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Showing 100 Latest Publications
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Erythropoietin-activated mesenchymal stem cells promote healing ulcers by improving microenvironment.Sunday, September 25, 2016
Lu H, Wu X, Wang Z, Li L, Chen W, Yang M, Huo D, Zeng W, Zhu C,
The Journal of surgical research. Oct-2016
Our results indicate that EPO-activated MSCs can promote the effective healing of diabetic foot ulcers. The mechanism is that EPO can change stem cells from excessive inflammation into general inflammation and improved diabetic foot ulcers inflammatory microenvironment.
The effect of ionized collagen for preventing postoperative adhesion.Sunday, September 25, 2016
Chung YS, Park SN, Ko JH, Bae SH, Lee S, Shim IK, Kim SC,
The Journal of surgical research. Oct-2016
This preclinical investigation indicated that ionized collagen materials readily formed clinically suitable shapes for easy handling without the need for any complex processing and effectively reduced postoperative tissue adhesion profiles compared to conventional antiadhesive agents.
Amyloid β precursor protein regulates neuron survival and maturation in the adult mouse brain.Saturday, September 24, 2016
Wang S, Bolós M, Clark R, Cullen C, Southam KA, Foa L, Dickson T, Young KM,
Molecular and cellular neurosciences. 21-Sep-2016
The amyloid-β precursor protein (APP) is a transmembrane protein that is widely expressed within the central nervous system (CNS). While the pathogenic dysfunction of this protein has been extensively studied in the context of Alzheimer's disease, its normal function is poorly understood, and reports have often appeared contradictory. In this study we have examined the role of APP in regulating neurogenesis in the adult mouse brain by comparing neural stem cell proliferation, as well as new neuron number and morphology between APP knockout mice and C57bl6 controls. Short-term EdU administration revealed that the number of proliferating EdU(+) neural progenitor cells and the number of PSA-NCAM(+) neuroblasts produced in the SVZ and dentate gyrus were not affected by the life-long absence of APP. However, by labelling newborn cells with EdU and then following their fate over-time, we determined that ~48% more newly generated EdU(+) NeuN(+) neurons accumulated in the granule cell layer of the olfactory bulb and ~57% more in the dentate gyrus of young adult APP knockout mice relative to C57bl6 controls. Furthermore, proportionally fewer of the adult-born olfactory bulb granule neurons were calretinin(+). To determine whether APP was having an effect on neuronal maturation, we administered tamoxifen to young adult Nestin-CreER(T2)::Rosa26-YFP and Nestin-CreER(T2)::Rosa26-YFP::APP-knockout mice, fluorescently labelling ~80% of newborn (EdU(+)) NeuN(+) dentate granule neurons formed between P75 and P105. Our analysis of their morphology revealed that neurons added to the hippocampus of APP knockout mice have shorter dendritic arbors and only half the number of branch points as those generated in C57bl6 mice. We conclude that APP reduces the survival of newborn neurons in the olfactory bulb and hippocampus, but that it does not influence all neuronal subtypes equally. Additionally, APP influences dentate granule neuron maturation, acting as a robust regulator of dendritic extension and arborisation.
Prime-boost therapeutic vaccination in mice with DNA/DNA or DNA/Fowlpox virus recombinants expressing the Human Papilloma Virus type 16 E6 and E7 mutated proteins fused to the coat protein of Potato virus X.Saturday, September 24, 2016
Illiano E, Bissa M, Paolini F, Zanotto C, De Giuli Morghen C, Franconi R, Radaelli A, Venuti A,
Virus research. 21-Sep-2016
The therapeutic antitumor potency of a prime-boost vaccination strategy was explored, based on the mutated, nontransforming forms of the E6 (E6F47R) and E7 (E7GGG) oncogenes of Human Papilloma Virus type 16 (HPV16), fused to the Potato virus X (PVX) coat protein (CP) sequence. Previous data showed that CP fusion improves the immunogenicity of tumor-associated antigens and may thus increase their efficacy. After verifying the correct expression of E6F47RCP and E7GGGCP inserted into DNA and Fowlpox virus recombinants by Western blotting and immunofluorescence, their combined use was evaluated for therapy in a pre-clinical mouse model of HPV16-related tumorigenicity. Immunization protocols were applied using homologous (DNA/DNA) or heterologous (DNA/Fowlpox) prime-boost vaccine regimens. The humoral immune responses were determined by ELISA, and the therapeutic efficacy evaluated by the delay in tumor appearance and reduced tumor volume after inoculation of syngeneic TC-1* tumor cells. Homologous DNA/DNA genetic vaccines were able to better delay tumor appearance and inhibit tumor growth when DNAE6F47RCP and DNAE7GGGCP were administered in combination. However, the heterologous DNA/Fowlpox vaccination strategy was able to delay tumor appearance in a higher number of animals when E6F47RCP and in particular E7GGGCP were administered alone.
Donepezil promotes differentiation of neural stem cells into mature oligodendrocytes at the expense of astrogenesis.Saturday, September 24, 2016
Imamura O, Arai M, Dateki M, Takishima K,
Journal of neurochemistry. 24-Sep-2016
Oligodendrocytes are the myelin-forming cells of the central nervous system. Oligodendrocyte loss and failure of myelin development result in serious human disorders, including multiple sclerosis. Previously, using oligodendrocyte progenitor cells, we have shown that donepezil, which is an acetylcholinesterase inhibitor developed for the treatment of Alzheimer's disease, stimulates myelin gene expression and oligodendrocyte differentiation. Here, we aimed to analyze the effects of donepezil on primary mouse embryonic neural stem cells (NSCs). Donepezil treatment led to impaired self-renewal ability and increased apoptosis. These effects appeared to be mediated through the Akt/Bad signaling pathway. Using neurosphere differentiation analysis, we observed that donepezil leads to reduced numbers of astrocytes and increased numbers of oligodendrocytes and neurons. Consistent with this finding, mRNA and protein levels for the oligodendrocyte markers myelin-associated glycoprotein (MAG), 2', 3'-Cyclic-nucleotide 3'-phosphodiesterase (CNPase), and myelin basic protein (MBP), as well as the neuronal marker β-tubulin type III (Tuj1) were upregulated. In contrast, the expression of the astrocyte marker glial fibrillary acidic protein (GFAP) was downregulated by donepezil in a dose- and time-dependent manner. Moreover, donepezil increased oligodendrocyte differentiation, resulting in a reduction in the differentiation of NSCs into astrocytes, by suppressing the activation of signal transducer and activator of transcription 3 (STAT3), SMAD1/5/9, and the downstream target gene GFAP, even under astrocyte-inducing conditions. These results suggest that efficient differentiation of NSCs into oligodendrocytes by donepezil may indicate a novel therapeutic role for this drug in promoting repair in demyelinated lesions in addition to its role in preventing astrogenesis. This article is protected by copyright. All rights reserved.
Distribution of the obligate endosymbiont Blochmannia floridanus and expression analysis of putative immune genes in ovaries of the carpenter ant Camponotus floridanus.Saturday, September 24, 2016
Kupper M, Stigloher C, Feldhaar H, Gross R,
Arthropod structure & development. 21-Sep-2016
The bacterial endosymbiont Blochmannia floridanus of the carpenter ant Camponotus floridanus contributes to its hosts' ontogeny via nutritional upgrading during metamorphosis. This primary endosymbiosis is essential for both partners and vertical transmission of the endosymbionts is guaranteed by bacterial infestation of oocytes. Here we present a detailed analysis of the presence and localisation of B. floridanus in the ants' ovaries obtained by FISH and TEM analyses. The most apical part of the germarium harbouring germ-line stem cells (GSCs) is not infected by the bacteria. The bacteria are detectable for the first time in lower parts of the germarium when cystocytes undergo the 4(th) and 5(th) division and B. floridanus infects somatic cells lying under the basal lamina surrounding the ovarioles. With the beginning of cystocyte differentiation, the endosymbionts are exclusively transported from follicle cells into the growing oocytes. This infestation of the oocytes by bacteria very likely involves exocytosis-endocytosis processes between follicle cells and the oocytes. Nurse cells were never found to harbour the endosymbionts. Furthermore we present first gene expression data in C. floridanus ovaries. These data indicate a modulation of immune gene expression which may facilitate tolerance towards the endosymbionts and thus may contribute to their transovarial transmission.
Mineralocorticoid Receptor Antagonists-A New Sprinkle of Salt and Youth.Sunday, September 25, 2016
Stojadinovic O, Lindley LE, Jozic I, Tomic-Canic M,
The Journal of investigative dermatology. Oct-2016
Skin atrophy and impaired cutaneous wound healing are the recognized side effects of topical glucocorticoid (GC) therapy. Although GCs have high affinity for the glucocorticoid receptor, they also bind and activate the mineralocorticoid receptor. In light of this, one can speculate that some of the GC-mediated side effects can be remedied by blocking activation of the mineralocorticoid receptor. Indeed, according to Nguyen et al., local inhibition of the mineralocorticoid receptor via antagonists (spironolactone, canrenoate, and eplerenone) rescues GC-induced delayed epithelialization and accelerates wound closure in diabetic animals by targeting epithelial sodium channels and stimulating keratinocyte proliferation. These findings suggest that the use of mineralocorticoid receptor antagonists coupled with GC therapy may be beneficial in overcoming at least some of the GC-mediated side effects.
Autophagy stimulated proliferation of porcine PSCs might be regulated by the canonical Wnt signaling pathway.Saturday, September 24, 2016
Ren L, Han W, Yang H, Sun F, Xu S, Hu S, Zhang M, He X, Hua J, Peng S,
Biochemical and biophysical research communications. 21-Sep-2016
Porcine pancreatic stem cells (PSCs) are one kind of the potential cells for treatment of human diabetes. Autophagy is a highly conserved cellular degradation process in which it helps to maintain the balance between the synthesis, degradation and subsequent recycling of cellular components. However, how autophagy contributes to PSCs has not yet been investigated. Here, we established GFP-LC3 transfected porcine PSC lines in which the accumulation of autophagosomes can be efficiently visualized to evaluate the autophagic activity. Moreover, we observed that starved PSCs which showed increased autophagic activity exhibited an increased tendency to proliferate through the results of BrdU, flow cytometry and western blotting. Furthermore, increased expression of active β-catenin after inducing autophagy indicated that it might be the canonical Wnt signaling that autophagy activated to exert the function on the stimulation of PSCs proliferation. Collectively, these results demonstrated that autophagy stimulated proliferation of PSCs might be regulated by the canonical Wnt signaling pathway. Our results for the first time shed light on a role of autophagy for stimulating the proliferation of porcine PSCs.
Azithromycin modulates immune response of human monocyte-derived dendritic cells and Cd4(+) T cells.Saturday, September 24, 2016
Lin SJ, Kuo ML, Hsiao HS, Lee PT,
International immunopharmacology. 21-Sep-2016
Azithromycin (AZM) is a macrolide antibiotic that exhibits anti-inflammatory activity aside from its antimicrobial effect, a feature that may ameliorate certain inflammatory disorders and prevent graft-versus-host disease in patients receiving stem cell transplantation. In the present study, we investigated the ability of AZM to influence the function of human monocyte-derived dendritic cells (DCs) and CD4(+) T cells. We found that AZM down-regulated CD80, CD86, and HLA-DR expression in lipopolysaccharide (LPS)-stimulated DCs and suppressed interleukin (IL)-6, IL-10, IL-12, and tumor necrosis factor-alpha production in these cells. In addition, AZM increased endocytosis and/or expression of Toll-like receptor (TLR)2, TLR4, and TLR9 in DCs and suppressed anti-CD3/CD28-induced CD4(+) T cell proliferation and interferon-gamma production, an effect that was synergistic with dexamethasone. Finally, AZM suppressed DC-induced allogeneic T cell proliferation and cytokine production. Our study demonstrates that AZM modulates DC and CD4(+) T cell function and may be of therapeutic benefit in various inflammatory disorders.
Neohesperidin suppresses osteoclast differentiation, bone resorption and ovariectomised-induced osteoporosis in mice.Saturday, September 24, 2016
Tan Z, Cheng J, Liu Q, Zhou L, Wang T, Lin X, Yuan J, Quinn JM, Tickner J, Qin A, Zhao J, Xu J,
Molecular and cellular endocrinology. 21-Sep-2016
Excessive bone resorption by osteoclasts plays an important role in osteoporosis. Bone loss occurs in ovariectomised (OVX) mice in a similar manner to that in humans, so this model is suitable for evaluating potential new therapies for osteoporosis. Neohesperidin (NE) is a flavonoid compound isolated from citrus fruits. Its role in bone metabolism is unknown. In this study we found that neohesperidin inhibits osteoclast differentiation, bone resorption and the expression of osteoclast marker genes, tartrate-resistant acid phosphatase and cathepsin K. In addition, neohesperidin inhibited receptor activator of NF-kappaB ligand (RANKL)-induced activation of NF-κB, and the degradation of inhibitor of kappa B-alpha (IκBα). Furthermore, neohesperidin inhibited RANKL induction of nuclear factor of activated T-cells (NFAT) and calcium oscillations. In vivo treatment of ovariectomised mice with neohesperidin protected against bone loss in mice. The results suggest neohesperidin has anti-osteoclastic effects in vitro and in vivo and possesses therapeutic potential as a natural anti-catabolic treatment in osteoporosis.
Novel Multiplex Fluorescent PCR-Based Method for HLA Typing and Preimplantational Genetic Diagnosis of β-Thalassemia.Sunday, September 25, 2016
Khosravi S, Salehi M, Ramezanzadeh M, Mirzaei H, Salehi R,
Archives of medical research. May-2016
The optimized protocol worked well in PGD clinical cycle for selection of thalassemia-unaffected embryos with the desired HLA system.
Alterations in membrane trafficking and pathophysiological implications in lysosomal storage disorders.Saturday, September 24, 2016
Kuech EM, Brogden G, Naim HY,
Biochimie. 21-Sep-2016
Lysosomal storage disorders are a heterogeneous group of more than 50 distinct inborn metabolic diseases affecting about 1 in 5000 to 7000 live births. The diseases often result from mutations followed by functional deficiencies of enzymes or transporters within the acidic environment of the lysosome, which mediate the degradation of a wide subset of substrates, including glycosphingolipids, glycosaminoglycans, cholesterol, glycogen, oligosaccharides, peptides and glycoproteins, or the export of the respective degradation products from the lysosomes. The progressive accumulation of uncleaved substrates occurs in multiple organs and finally causes a broad spectrum of different pathologies including visceral, neurological, skeletal and hematologic manifestations. Besides deficient lysosomal enzymes and transporters other defects may lead to lysosomal storage disorders, including activator defects, membrane defects or defects in modifier proteins. In this review we concentrate on four different lysosomal storage disorders: Niemann-Pick type C, Fabry disease, Gaucher disease and Pompe disease. While the last three are caused by defective lysosomal hydrolases, Niemann-Pick type C is caused by the inability to export LDL-derived cholesterol out of the lysosome. We want to emphasise potential implications of membrane trafficking defects on the pathology of these diseases, as many mutations interfere with correct lysosomal protein trafficking and alter cellular lipid homeostasis. Current therapeutic strategies are summarised, including substrate reduction therapy as well as pharmacological chaperone therapy which directly aim to improve folding and lysosomal transport of misfolded mutant proteins.
PhIP/DSS-induced Colon Carcinogenesis in CYP1A-humanized Mice and the Possible Role of Lgr5+ Stem Cells.Saturday, September 24, 2016
Chen JX, Wang H, Liu A, Zhang L, Reuhl K, Yang CS,
Toxicological sciences : an official journal of the Society of Toxicology. 23-Sep-2016
In the past decades, experimental rodent models developed to study the pathogenesis of human colorectal cancer (CRC) generally employed synthetic chemical carcinogens or genetic manipulation. Our lab, in order to establish a more physiologically relevant CRC model, recently developed a colon carcinogenesis model induced by the meat-derived dietary carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), and promoted by dextran sodium sulfate (DSS)-induced colitis in the cytochrome P450 1A-humanized (hCYP1A) mice. The resulting colon tumors shared many histologic and molecular features of human colon cancer. In the present study, we characterized the early stages of PhIP/DSS-induced colon carcinogenesis. We found that PhIP/DSS treatments caused rapid destruction of the colon mucosa with severe inflammation, followed by the presence of reactive changes and low-grade dysplastic lesions, and then manifestation of high-grade dysplastic lesions and finally adenocarcinomas. Molecular analysis of the early time-points (i.e., days 1, 3, 7, 11, 14, and 21 after DSS exposure) indicates Ctnnb1/β-catenin mutations and β-catenin nuclear accumulation in the high-grade dysplastic lesions, but not low-grade dysplastic lesions or adjacent normal tissues. In addition, we investigated the role of Lgr5+ colon stem cells in the PhIP/DSS-induced colon carcinogenesis and found the presence of Lgr5-EGFP-expressing cells amidst some ulcerated mucosa, high-grade dysplastic lesions and adenocarcinomas, suggesting a possible role of Lgr5+ stem cells in this dietary carcinogen-induced, inflammation-promoted colon carcinogenesis model. Overall, the findings suggest that PhIP/DSS-induced colon carcinogenesis is likely initiated by dominant active Ctnnb1/β-catenin mutation in residual epithelial cells, which when promoted by colitis, developed into high-grade dysplasia and adenocarcinoma.
Screening ToxCastTM prioritized chemicals for PPARG function in a human adipose-derived stem cell model of adipogenesis.Saturday, September 24, 2016
Foley B, Doheny D, Black M, Pendse SN, Wetmore B, Clewell R, Andersen ME, Deisenroth C,
Toxicological sciences : an official journal of the Society of Toxicology. 23-Sep-2016
The developmental origins of obesity hypothesis posits a multifaceted contribution of factors to the fetal origins of obesity and metabolic disease. Adipocyte hyperplasia in gestation and early childhood may result in predisposition for obesity later in life. Rodent in vitro and in vivo studies indicate that some chemicals may directly affect adipose progenitor cell differentiation, but the human relevance of these findings is unclear. The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARG) is the master regulator of adipogenesis. Human adipose-derived stem cells (hASC) isolated from adipose tissue express endogenous isoforms of PPARG and represent a biologically relevant cell-type for evaluating activity of PPARG ligands. Here, a multi-endpoint approach based on a phenotypic adipogenesis assay was applied to screen a set of 60 chemical compounds identified in ToxCast(TM) Phase I as PPARG active (49) or inactive (11). Chemicals showing activity in the adipogenesis screen were further evaluated in a series of 4 orthogonal assays representing 7 different key events in PPARG-dependent adipogenesis, including gene transcription, protein expression, and adipokine secretion. An siRNA screen was also used to evaluate PPARG-dependence of the adipogenesis phenotype. A universal concentration-response design enabled inter-assay comparability and implementation of a weight-of-evidence approach for bioactivity classification. Collectively, a total of 14/49 (29%) prioritized chemicals were identified with moderate-to-strong activity for human adipogenesis. These results provide the first integrated screening approach of prioritized ToxCast(TM) chemicals in a human stem cell model of adipogenesis and provide insight into the capacity of PPARG-activating chemicals to modulate early-life programming of adipose tissue.
Upregulation of neurovascular communication through filamin abrogation promotes ectopic periventricular neurogenesis.Saturday, September 24, 2016
Houlihan SL, Lanctot AA, Guo Y, Feng Y,
eLife. 24-Sep-2016
Neuronal fate-restricted intermediate progenitors (IPs) are derived from the multipotent radial glia (RGs) and serve as the direct precursors for cerebral cortical neurons, but factors that control their neurogenic plasticity remain elusive. Here we report that IPs' neuron production is enhanced by abrogating filamin function, leading to the generation of periventricular neurons independent of normal neocortical neurogenesis and neuronal migration. Loss of Flna in neural progenitor cells (NPCs) led RGs to undergo changes resembling epithelial-mesenchymal transition (EMT) along with exuberant angiogenesis that together changed the microenvironment and increased neurogenesis of IPs. We show that by collaborating with β-arrestin, Flna maintains the homeostatic signaling between the vasculature and NPCs, and loss of this function results in escalated Vegfa and Igf2 signaling, which exacerbates both EMT and angiogenesis to further potentiate IPs' neurogenesis. These results suggest that the neurogenic potential of IPs may be boosted in vivo by manipulating Flna-mediated neurovascular communication.
Unilateral hip osteoarthritis: The effect of compensation strategies and anatomic measurements on frontal plane joint loading.Saturday, September 24, 2016
Schmidt A, Meurer A, Lenarz K, Vogt L, Froemel D, Lutz F, Barker J, Stief F,
Journal of orthopaedic research : official publication of the Orthopaedic Research Society. 24-Sep-2016
In order to reduce pain caused by the affected hip joint, unilateral hip osteoarthritis patients (HOAP) adopt characteristic gait patterns. However, it is unknown if the knee and hip joint loading in the non-affected (limbnon-affected ) and the affected (limbaffected ) limb differ from healthy controls (HC) and which gait parameters correlate with potential abnormal joint loading. Instrumented 3D-gait analysis was performed on 18 HOAP and 18 sex, age, and height matched HC. The limbnon-affected showed greater 1(st) and 2(nd) peak external hip adduction moments (1(st) HAM: +15%, p = 0.014; 2(nd) HAM: +15%, p = 0.021, respectively), than seen in HC. In contrast, the 2(nd) peak external knee adduction moment (KAM) in the limbaffected is reduced by about 23% and 30% compared to the limbnon-affected and HC, respectively. Furthermore, our patients showed characteristic gait compensation strategies including reduced peak vertical forces (pvF), a greater foot progression angle (FPA), and reduced knee range of motion (ROM) in the limbaffected . The limbaffected was 5.6 ± 3.8 mm shorter than the limbnon-affected . Results of stepwise regression analyses showed that increased 1(st) pvF explain 16% of 1(st) HAM alterations whereas knee ROM and FPA explain 39% of 2(nd) KAM alterations. We therefore expect an increased rate of progression of OA in the hip joint of the limbnon-affected and suggest that the shift in the medial-to-lateral knee joint load distribution may impact the rate of progression of OA in the limbaffected . The level of evidence is III. This article is protected by copyright. All rights reserved.
Quiescent Pluripotent Stem Cells Reside within Murine Peripheral Nerves that Can Be Stimulated to Proliferate by rhBMP-2 or by Nerve Trauma.Saturday, September 24, 2016
Heggeness MH, Strong N, Wooley PH, Yang SY,
The spine journal : official journal of the North American Spine Society. 21-Sep-2016
Exposure to BMP-2 causes a marked proliferation of previously quiescent cells within peripheral nerves. These cells simultaneously express KLF4, Sox2, Oct4, and c-Myc, the transcription factors that confer embryonic pluripotency. Work described in the companion paper reveals some of the differentiation capacity of the cells and their likely clinical significance. In addition, the effects of direct exposure of nerves to rhBMP-2 as described here should clearly illuminate the mechanism of BMP2 related nerve complications. We would suggest that the use of this agent in proximity to known neural structures should only be done with extreme caution.
"Early NK Cell Reconstitution Predicts Overall Survival in T-Cell Replete Allogeneic Hematopoietic Stem Cell Transplantation".Saturday, September 24, 2016
Minculescu L, Marquart HV, Friis LS, Petersen SL, Schiødt I, Ryder LP, Andersen NS, Sengeloev H,
Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation. 21-Sep-2016
Early immune reconstitution plays a critical role in clinical outcome after allogeneic hematopoietic stem cell transplantation (HSCT). Natural killer (NK) cells are the first lymphocytes to recover after transplantation and are considered powerful effector cells in HSCT. We aimed to evaluate the clinical impact of early NK cell recovery in T-cell replete transplant recipients. Immune reconstitution was studied in 298 adult patients undergoing HSCT for acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL) and myelodysplastic syndrome (MDS) from 2005 to 2013. In multivariate analysis NK cell numbers day 30 (NK30) >150cells/µL were independently associated with superior overall survival (hazard ratio 0.79, 95% confidence interval 0.66-0.95, p=0.01). Cumulative incidence analyses showed that patients with NK30 >150cells/µL had significantly less transplant related mortality (TRM), p=0.01. Patients with NK30 >150cells/µL experienced significantly lower numbers of life threatening bacterial infections as well as viral infections, including CMV. No association was observed in relation to relapse. These results suggest an independent protective effect of high early NK cell reconstitution on TRM which translates into improved overall survival after T-cell replete HSCT.
Constitutive Kit activity triggers B cell acute lymphoblastic leukemia-like disease in mice.Saturday, September 24, 2016
Weidemann RR, Behrendt R, Schoedel KB, Müller W, Roers A, Gerbaulet A,
Experimental hematology. 21-Sep-2016
Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy and is of pro- or pre-B cell origin in most cases. The receptor tyrosine kinase KIT is expressed by hematopoietic stem and precursor cells. Gain-of-function mutations of KIT cause systemic mastocytosis, which is characterized by abnormal accumulations of mast cells. We previously reported a mouse model of mastocytosis based on conditional expression of a constitutively active Kit protein. Half of these animals developed leukemic disease of B lineage origin. Herein, we report that this condition bears striking similarities to human B-ALL. The immuno-phenotype of the leukemic cells was compatible with a pro-B cell origin, as was the finding of immunoglobulin heavy chain gene rearrangements in all cases, whereas light chain loci were mostly not rearranged. Leukemogenesis was independent of pre-B cell receptor expression. Primary leukemic cells and permanent cell lines derived from these were serially transplantable and rapidly killed the recipients. In few animals, the leukemia was of T cell origin with abnormal CD4/8 double positive T cell precursors dominating in the circulation. In summary, we report a novel ALL mouse model that may prove useful for in vivo drug testing and identification of novel oncogenic mutations and principles.
Gene Therapy and Stem Cell Transplantation in Retinal Disease: The New Frontier.Saturday, September 24, 2016
MacLaren RE, Bennett J, Schwartz SD,
Ophthalmology. Oct-2016
Gene and cell therapies have the potential to prevent, halt, or reverse diseases of the retina in patients with currently incurable blinding conditions. Over the past 2 decades, major advances in our understanding of the pathobiologic basis of retinal diseases, coupled with growth of gene transfer and cell transplantation biotechnologies, have created optimism that previously blinding retinal conditions may be treatable. It is now possible to deliver cloned genes safely and stably to specific retinal cell types in humans. Preliminary results testing gene augmentation strategies in human recessive diseases suggest promising safety and efficacy profiles, including improved visual function outcomes over extended periods. Additional gene-based strategies under development include approaches to autosomal dominant disease ("gain of function"), attempts to deliver genes encoding therapeutic proteins with proven mechanisms of action interfering with specific disease pathways, and approaches that could be used to render retinal cells other than atrophied photoreceptors light sensitive. In the programs that are the furthest along-pivotal regulatory safety and efficacy trials studying individuals with retinal degeneration resulting from RPE65 mutations-initial results reveal a robust safety profile and clinically significant improvements in visual function, thereby making this program a frontrunner for the first approved gene therapy product in the United States. Similar to gene therapy, progress in regenerative or stem cell-based transplantation strategies has been substantial. It is now possible to deliver safely stem cell-derived, terminally differentiated, biologically and genetically defined retinal pigment epithelium (RPE) to the diseased human eye. Although demonstration of clinical efficacy is still well behind the gene therapy field, multiple programs investigating regenerative strategies in RPE disease are beginning to enroll subjects, and initial results suggest possible signs of efficacy. Stem cells capable of becoming other retinal cell types, such as photoreceptors, are on the cusp of clinical trials. Stem cell-derived transplants can be delivered to precise target locations in the eye, and their ability to ameliorate, reverse, regenerate, or neuroprotect against disease processes can be assessed. Results from these studies will provide foundational knowledge that may lead to clinically significant therapies for currently untreatable retinal disease.
Cap-independent translation by DAP5 controls cell fate decisions in human embryonic stem cells.Saturday, September 24, 2016
Yoffe Y, David M, Kalaora R, Povodovski L, Friedlander G, Feldmesser E, Ainbinder E, Saada A, Bialik S, Kimchi A,
Genes & development. 1-Sep-2016
Multiple transcriptional and epigenetic changes drive differentiation of embryonic stem cells (ESCs). This study unveils an additional level of gene expression regulation involving noncanonical, cap-independent translation of a select group of mRNAs. This is driven by death-associated protein 5 (DAP5/eIF4G2/NAT1), a translation initiation factor mediating IRES-dependent translation. We found that the DAP5 knockdown from human ESCs (hESCs) resulted in persistence of pluripotent gene expression, delayed induction of differentiation-associated genes in different cell lineages, and defective embryoid body formation. The latter involved improper cellular organization, lack of cavitation, and enhanced mislocalized apoptosis. RNA sequencing of polysome-associated mRNAs identified candidates with reduced translation efficiency in DAP5-depleted hESCs. These were enriched in mitochondrial proteins involved in oxidative respiration, a pathway essential for differentiation, the significance of which was confirmed by the aberrant mitochondrial morphology and decreased oxidative respiratory activity in DAP5 knockdown cells. Further analysis identified the chromatin modifier HMGN3 as a cap-independent DAP5 translation target whose knockdown resulted in defective differentiation. Thus, DAP5-mediated translation of a specific set of proteins is critical for the transition from pluripotency to differentiation, highlighting the importance of cap-independent translation in stem cell fate decisions.
Superenhancer reprogramming drives a B-cell-epithelial transition and high-risk leukemia.Saturday, September 24, 2016
Hu Y, Zhang Z, Kashiwagi M, Yoshida T, Joshi I, Jena N, Somasundaram R, Emmanuel AO, Sigvardsson M, Fitamant J, El-Bardeesy N, Gounari F, Van Etten RA, Georgopoulos K,
Genes & development. 1-Sep-2016
IKAROS is required for the differentiation of highly proliferative pre-B-cell precursors, and loss of IKAROS function indicates poor prognosis in precursor B-cell acute lymphoblastic leukemia (B-ALL). Here we show that IKAROS regulates this developmental stage by positive and negative regulation of superenhancers with distinct lineage affiliations. IKAROS defines superenhancers at pre-B-cell differentiation genes together with B-cell master regulators such as PAX5, EBF1, and IRF4 but is required for a highly permissive chromatin environment, a function that cannot be compensated for by the other transcription factors. IKAROS is also highly enriched at inactive enhancers of genes normally expressed in stem-epithelial cells. Upon IKAROS loss, expression of pre-B-cell differentiation genes is attenuated, while a group of extralineage transcription factors that are directly repressed by IKAROS and depend on EBF1 relocalization at their enhancers for expression is induced. LHX2, LMO2, and TEAD-YAP1, normally kept separate from native B-cell transcription regulators by IKAROS, now cooperate directly with them in a de novo superenhancer network with its own feed-forward transcriptional reinforcement. Induction of de novo superenhancers antagonizes Polycomb repression and superimposes aberrant stem-epithelial cell properties in a B-cell precursor. This dual mechanism of IKAROS regulation promotes differentiation while safeguarding against a hybrid stem-epithelial-B-cell phenotype that underlies high-risk B-ALL.
Assessment of 'one-step' versus 'sequential' embryo culture conditions through embryonic genome methylation and hydroxymethylation changes.Saturday, September 24, 2016
Salvaing J, Peynot N, Bedhane MN, Veniel S, Pellier E, Boulesteix C, Beaujean N, Daniel N, Duranthon V,
Human reproduction (Oxford, England). 22-Sep-2016
This work was supported by an 'AMP diagnostic prénatal et diagnostic génétique' 2012 grant from the French Agence de la Biomédecine. This study was performed within the framework of ANR LABEX 'REVIVE' (ANR-10-LABX-73). Authors are members of RGB-Net (TD 1101) and Epiconcept (FA 1201) COST actions. The authors declare that there is no competing interest.
Role of circadian gene Clock during differentiation of mouse pluripotent stem cells.Saturday, September 24, 2016
Lu C, Yang Y, Zhao R, Hua B, Xu C, Yan Z, Sun N, Qian R,
Protein & cell. 23-Sep-2016
Biological rhythms controlled by the circadian clock are absent in embryonic stem cells (ESCs). However, they start to develop during the differentiation of pluripotent ESCs to downstream cells. Conversely, biological rhythms in adult somatic cells disappear when they are reprogrammed into induced pluripotent stem cells (iPSCs). These studies indicated that the development of biological rhythms in ESCs might be closely associated with the maintenance and differentiation of ESCs. The core circadian gene Clock is essential for regulation of biological rhythms. Its role in the development of biological rhythms of ESCs is totally unknown. Here, we used CRISPR/CAS9-mediated genetic editing techniques, to completely knock out the Clock expression in mouse ESCs. By AP, teratoma formation, quantitative real-time PCR and Immunofluorescent staining, we did not find any difference between Clock knockout mESCs and wild type mESCs in morphology and pluripotent capability under the pluripotent state. In brief, these data indicated Clock did not influence the maintaining of pluripotent state. However, they exhibited decreased proliferation and increased apoptosis. Furthermore, the biological rhythms failed to develop in Clock knockout mESCs after spontaneous differentiation, which indicated that there was no compensational factor in most peripheral tissues as described in mice models before (DeBruyne et al., 2007b). After spontaneous differentiation, loss of CLOCK protein due to Clock gene silencing induced spontaneous differentiation of mESCs, indicating an exit from the pluripotent state, or its differentiating ability. Our findings indicate that the core circadian gene Clock may be essential during normal mESCs differentiation by regulating mESCs proliferation, apoptosis and activity.
Targeting Immune Checkpoints in Hematologic Malignancies.Saturday, September 24, 2016
Alatrash G, Daver N, Mittendorf EA,
Pharmacological reviews. Oct-2016
The use of antibodies that target immune checkpoint molecules on the surface of T-lymphocytes and/or tumor cells has revolutionized our approach to cancer therapy. Cytotoxic-T-lymphocyte antigen (CTLA-4) and programmed cell death protein 1 (PD-1) are the two most commonly targeted immune checkpoint molecules. Although the role of antibodies that target CTLA-4 and PD-1 has been established in solid tumor malignancies and Food and Drug Administration approved for melanoma and non-small cell lung cancer, there remains a desperate need to incorporate immune checkpoint inhibition in hematologic malignancies. Unlike solid tumors, a number of considerations must be addressed to appropriately employ immune checkpoint inhibition in hematologic malignancies. For example, hematologic malignancies frequently obliterate the bone marrow and lymph nodes, which are critical immune organs that must be restored for appropriate response to immune checkpoint inhibition. On the other hand, hematologic malignancies are the quintessential immune responsive tumor type, as proven by the success of allogeneic stem cell transplantation (allo-SCT) in hematologic malignancies. Also, sharing an immune cell lineage, malignant hematologic cells often express immune checkpoint molecules that are absent in solid tumor cells, thereby offering direct targets for immune checkpoint inhibition. A number of clinical trials have demonstrated the potential for immune checkpoint inhibition in hematologic malignancies before and after allo-SCT. The ongoing clinical studies and complimentary immune correlatives are providing a growing body of knowledge regarding the role of immune checkpoint inhibition in hematologic malignancies, which will likely become part of the standard of care for hematologic malignancies.
Noninvasive in-vivo tracing and imaging of transplanted stem cells for liver regeneration.Saturday, September 24, 2016
Cen P, Chen J, Hu C, Fan L, Wang J, Li L,
Stem cell research & therapy. 25-9-2016
Terminal liver disease is a major cause of death globally. The only ultimate therapeutic approach is orthotopic liver transplant. Because of the innate defects of organ transplantation, stem cell-based therapy has emerged as an effective alternative, based on the capacity of stem cells for multilineage differentiation and their homing to injured sites. However, the disease etiology, cell type, timing of cellular graft, therapeutic dose, delivery route, and choice of endpoints have varied between studies, leading to different, even divergent, results. In-vivo cell imaging could therefore help us better understand the fate and behaviors of stem cells to optimize cell-based therapy for liver regeneration. The primary imaging techniques in preclinical or clinical studies have consisted of optical imaging, magnetic resonance imaging, radionuclide imaging, reporter gene imaging, and Y chromosome-based fluorescence in-situ hybridization imaging. More attention has been focused on developing new or modified imaging methods for longitudinal and high-efficiency tracing. Herein, we provide a descriptive overview of imaging modalities and discuss recent advances in the field of molecular imaging of intrahepatic stem cell grafts.
Depletion of the fragile X mental retardation protein in embryonic stem cells alters the kinetics of neurogenesis.Saturday, September 24, 2016
Khalfallah O, Jarjat M, Davidovic L, Nottet N, Cestèle S, Mantegazza M, Bardoni B,
Stem cells (Dayton, Ohio). 24-Sep-2016
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability (ID) and a leading cause of autism. FXS is due to the silencing of the Fragile X Mental Retardation Protein (FMRP), an RNA binding protein mainly involved in translational control, dendritic spine morphology and synaptic plasticity. Despite extensive studies, there is currently no cure for FXS. With the purpose to decipher the initial molecular events leading to this pathology, we developed a stem-cell-based disease model by knocking-down the expression of Fmr1 in mouse embryonic stem cells (ESCs). Repressing FMRP in ESCs increased the expression of amyloid precursor protein (APP) and Ascl1. When inducing neuronal differentiation, βIII-tubulin, p27(kip1) , NeuN and NeuroD1 were up-regulated, leading to an accelerated neuronal differentiation, that was partially compensated at later stages. Interestingly, we observed that neurogenesis is also accelerated in the embryonic brain of Fmr1-knockout (KO) mice, indicating that our cellular model recapitulates the molecular alterations present in vivo. Importantly, we rescued the main phenotype of the Fmr1 knockdown cell line, not only by reintroducing FMRP but also by pharmacologically targeting APP processing, showing the role of this protein in the pathophysiology of FXS during the earliest steps of neurogenesis. Our work allows to define an early therapeutic window but also to identify more effective molecules for treating this disorder. This article is protected by copyright. All rights reserved.
Molecular and Functional Characterization of a Cohort of Spanish Patients with Ataxia-Telangiectasia.Saturday, September 24, 2016
Carranza D, Vega AK, Torres-Rusillo S, Montero E, Martinez LJ, Santamaría M, Santos JL, Molina IJ,
Neuromolecular medicine. 23-Sep-2016
Ataxia-telangiectasia is a multisystemic disease with severe neurological affectation, immunodeficiency and telangiectasia. The disorder is caused by alterations in the ATM gene, whose size and complexity make molecular diagnosis difficult. We designed a target-enrichment next-generation sequencing strategy to characterize 28 patients from several regions of Spain. This approach allowed us to identify gene variants affecting function in 54 out of the 56 alleles analyzed, although the two unresolved alleles belong to brothers. We found 28 ATM gene mutations, of which 10 have not been reported. A total of 171 gene variants not affecting function were also found, of which 22 are reported to predispose to disease. Interestingly, all Roma (Spanish Gypsies) patients are homozygous for the same mutation and share the H3 ATM haplotype, which is strong evidence of a founder effect in this population. In addition, we generated a panel of 27 primary T cell lines from A-T patients, which revealed significant expression of ATM in two patients and traces of the protein in nine more. None of them retained residual ATM activity, and almost all T cell lines show increased or intermediate radiosensitivity.
Restoring Regulatory T Cells in Type 1 Diabetes.Sunday, September 25, 2016
Spence A, Tang Q,
Current diabetes reports. Nov-2016
Genetic and cellular studies of type 1 diabetes in patients and in the nonobese diabetic mouse model of type 1 diabetes point to an imbalance between effector T cells and regulatory T cells (Tregs) as a driver of the disease. The imbalance may arise as a consequence of genetically encoded defects in thymic deletion of islet antigen-specific T cells, induction of islet antigen-specific thymic Tregs, unfavorable tissue environment for peripheral Treg induction, and failure of islet antigen-specific Tregs to survive in the inflamed islets secondary to insufficient IL-2 signals. These understandings are the foundation for rationalized design of new therapeutic interventions to restore the balance by selectively targeting effector T cells and boosting Tregs.
Underlying Mechanisms that Restore Spermatogenesis on Transplanting Healthy Niche Cells in Busulphan Treated Mouse Testis.Saturday, September 24, 2016
Anand S, Bhartiya D, Sriraman K, Mallick A,
Stem cell reviews. 23-Sep-2016
Very small embryonic-like stem cells (VSELs) exist among spermatogonial stem cells and survive chemotherapy in both mice and human testes because of their relatively quiescent nature. Our earlier study revealed that inter-tubular transplantation of niche (Sertoli or bone marrow derived mesenchymal) cells can restore spermatogenesis from endogenous surviving VSELs. Present study was undertaken to delineate the effect of busulphan on testicular stem/germ/Sertoli cells and to comprehend the underlying mechanisms of how transplanted niche cells restore spermatogenesis. Ploidy analysis showed an increase in diploid cells on D7 and VSELs (2-6 μm; LIN-/CD45-/SCA-1+) were detected at all time-points studied and were maximum on D15 after busulphan treatment. They were visualized in cell smears, expressed nuclear NANOG and SOX2 and BrdU uptake on D15 suggested they were proliferating in response to stress induced by busulphan. Verapamil-sensitive side population detected comprised SCA-1 positive stem cells (5 ± 0.02 % in normal and 8.6 ± 2.02 % in chemoablated testis). Adverse effects of busulphan on Sertoli cells by transcriptome analysis included altered expression of Gdnf, Scf, Fgf, Bmp4, androgen binding protein, components of blood-testis-barrier and also stem cells related signaling pathways including Wnt. GFP positive transplanted cells aligned themselves as 'neo-tubules' and were visualized adjacent to 'native' germ cells depleted tubules. 'Neo-tubules' provide paracrine support to endogenous VSELs to undergo spermatogenesis. Quantitative analysis was done to track proliferation (PCNA) and differentiation (MVH) of stem cells by immuno-localization studies at different time intervals. Results provide an alternative strategy to restore spermatogenesis in cancer survivors from endogenous stem cells which needs to be further researched.
Role of KEAP1/NRF2 and TP53 Mutations in Lung Squamous Cell Carcinoma Development and Radiation Resistance.Saturday, September 24, 2016
Jeong Y, Hoang NT, Lovejoy A, Stehr H, Newman AM, Gentles AJ, Kong W, Truong D, Martin S, Chaudhuri A, Heiser D, Zhou L, Say C, Carter JN, Hiniker SM, Loo BW, West RB, Beachy P, Alizadeh AA, Diehn M,
Cancer discovery. 23-Sep-2016
Lung squamous cell carcinomas (LSCC) pathogenesis remains incompletely understood and biomarkers predicting treatment response remain lacking. Here we describe novel murine LSCC models driven by loss of Trp53 and Keap1, both of which are frequently mutated in human LSCCs. Homozygous inactivation of Keap1 or Trp53 promoted airway basal stem cell (ABSC) self-renewal, suggesting that mutations in these genes lead to expansion of mutant stem cell clones. Deletion of Trp53 and Keap1 in ABSCs, but not more differentiated tracheal cells, produced tumors recapitulating histological and molecular features of human LSCCs, indicating that they represent the likely cell of origin in this model. Deletion of Keap1 promoted tumor aggressiveness, metastasis, and resistance to oxidative stress and radiotherapy (RT). KEAP1/NRF2 mutation status predicted risk of local recurrence after RT in non-small lung cancer (NSCLC) patients and could be non-invasively identified in circulating tumor DNA. Thus, KEAP1/NRF2 mutations could serve as predictive biomarkers for personalization of therapeutic strategies for NSCLCs.
The chromatin binding protein Smyd1 restricts adult mammalian heart growth.Saturday, September 24, 2016
Franklin S, Kimball T, Rasmussen TL, Rosa Garrido M, Chen H, Tran T, Miller MR, Gray R, Jiang S, Ren S, Wang Y, Tucker HO, Vondriska TM,
American journal of physiology. Heart and circulatory physiology. 23-Sep-2016
All terminally differentiated organs face two challenges: maintaining their cellular identity and restricting organ size. The molecular mechanisms responsible for these decisions are of critical importance to organismal development and perturbations in their normal balance can lead to disease. A hallmark of heart failure, a condition affecting millions of people worldwide, is hypertrophic growth of cardiomyocytes. The various forms of heart failure in humans and animals models share conserved transcriptome remodeling events that lead to expression of genes normally silenced in the healthy adult heart. However, the chromatin remodeling events that maintain cell and organ size are incompletely understood-insights into these mechanisms could provide new targets for heart failure therapy. Using a quantitative proteomics approach to identify muscle-specific chromatin regulators in a mouse model of hypertrophy and heart failure, we identified up-regulation of the histone methyltransferase Smyd1 during disease. Inducible loss-of-function studies in vivo demonstrate that Smyd1 is responsible for restricting growth in the adult heart, with its absence leading to cellular hypertrophy, organ remodeling and fulminate heart failure. Molecular studies reveal Smyd1 to be a muscle-specific regulator of gene expression and indicate that Smyd1 modulates expression of gene isoforms whose expression is associated with cardiac pathology. Importantly, activation of Smyd1 can prevent pathologic cell growth. These findings have basic implications for our understanding of cardiac pathologies and open new avenues to the treatment of cardiac hypertrophy and failure by modulating Smyd1.
RGTA-based matrix therapy - A new branch of regenerative medicine in locomotion.Saturday, September 24, 2016
Barritault D, Desgranges P, Meddahi-Pellé A, Denoix JM, Saffar JL,
Joint, bone, spine : revue du rhumatisme. 20-Sep-2016
Matrix therapy is an innovative, minimally invasive approach in the field of regenerative medicine, that aims to promote tissue regeneration by reconstructing the cellular microenvironment following tissue injury. This approach has significant therapeutic potential in the treatment of pathologies characterized by tissue inflammation and damage, or following injury, conditions which can be incapacitating and cost-consuming. Heparan sulfate mimics, termed ReGeneraTing Agents (RGTAs) have emerged as a unifying approach to treat these diverse pathologies. Today, skin and corneal healing topical products have already been used in clinics, demonstrating a proof of concept in humans. In this review, we present key evidence that RGTAs regenerate damaged tissue in bone, muscle, tendon and nerve, with astonishing results. In animal models of bone surgical defects and inflammatory bone loss, RGTA induced healing of injured bones by controlling inflammation and bone resorption, and stimulated bone formation by coordinating vascularization, recruitment and differentiation of competent cells from specific niches, restoring tissue quality to that of uninjured tissue, evoking true regeneration. In models of muscle injury, RGTA had marked effects on healing speed and quality, evidenced by increased muscle fiber density, maturation, vascularization and reduced fibrosis, more mature motor endplates and functional recovery. Applications merging RGTA-based matrix therapy and cell therapy, combining Extra-Cellular Matrix reconstruction with cells required for optimal tissue repair show significant promise. Hence restoration of the proper microenvironment is a new paradigm in regenerative medicine. Harnessing the potential of RGTA in this brave, new vision of regenerative therapy will therefore be the focus of future studies.
Human adenosine deaminases ADA1 and ADA2 bind to different subsets of immune cells.Saturday, September 24, 2016
Kaljas Y, Liu C, Skaldin M, Wu C, Zhou Q, Lu Y, Aksentijevich I, Zavialov AV,
Cellular and molecular life sciences : CMLS. 23-Sep-2016
At sites of inflammation and tumor growth, the local concentration of extracellular adenosine rapidly increases and plays a role in controlling the immune responses of nearby cells. Adenosine deaminases ADA1 and ADA2 (ADAs) decrease the level of adenosine by converting it to inosine, which serves as a negative feedback mechanism. Mutations in the genes encoding ADAs lead to impaired immune function, which suggests a crucial role for ADAs in immune system regulation. It is not clear why humans and other mammals possess two enzymes with adenosine deaminase activity. Here, we found that ADA2 binds to neutrophils, monocytes, NK cells and B cells that do not express CD26, a receptor for ADA1. Moreover, the analysis of CD4+ T-cell subset revealed that ADA2 specifically binds to regulatory T cells expressing CD39 and lacking the receptor for ADA1. Also, it was found that ADA1 binds to CD16- monocytes, while CD16+ monocytes preferably bind ADA2. A study of the blood samples from ADA2-deficient patients showed a dramatic reduction in the number of lymphocyte subsets and an increased concentration of TNF-α in plasma. Our results suggest the existence of a new mechanism, where the activation and survival of immune cells is regulated through the activities of ADA2 or ADA1 anchored to the cell surface.
MOZ (KAT6A) is essential for the maintenance of classically defined adult hematopoietic stem cells.Saturday, September 24, 2016
Sheikh BN, Yang Y, Schreuder J, Nilsson SK, Bilardi R, Carotta S, McRae HM, Metcalf D, Voss AK, Thomas T,
Blood. 23-Sep-2016
Hematopoietic stem cells (HSCs) are conventionally thought to be at the apex of a hierarchy that produces all mature cells of the blood. The quintessential property of these cells is their ability to reconstitute the entire hematopoietic system of hemoablated recipients. This characteristic has enabled HSCs to be used to replenish the hematopoietic system of patients after chemotherapy or radiotherapy. Here, we use deletion of the monocytic leukemia zinc finger gene (Moz/Kat6a/Myst3) to examine the effects of removing HSCs. Loss of MOZ, in adult mice leads to the rapid loss of HSCs as defined by transplantation. This is accompanied by a reduction of the LSK-CD48(-)CD150(+) and LSK-CD34(-)Flt3(-) populations in the bone marrow and a reduction in quiescent cells in G0 Surprisingly, the loss of classically defined HSCs did not affect mouse viability and there was no recovery of the LSK-CD48(-)CD150(+) and LSK-CD34(-)Flt3(-) populations 15-18 months after Moz deletion. Clonal analysis of myeloid progenitors, which produce short-lived granulocytes, demonstrate that these are derived from cells that had undergone recombination at the Moz locus up to 2 years earlier, suggesting that early progenitors have acquired extended self-renewal. Our results establish that there are essential differences in HSC requirement for steady state blood cell production compared to the artificial situation of reconstitution after transplantation into a hemoablated host. A better understanding of steady state hematopoiesis may facilitate the development of novel therapies engaging hematopoietic cell populations with previously unrecognized traits, as well as characterizing potential vulnerability to oncogenic transformation.
Interleukin-12 modulates the immunomodulatory properties of human periodontal ligament cells.Saturday, September 24, 2016
Issaranggun Na Ayuthaya B, Satravaha P, Pavasant P,
Journal of periodontal research. 24-Sep-2016
Expression of IL-12 during periodontitis may play an important role in the control of the inflammatory response via the induction of immunosuppressive molecules by hPDL cells. We hypothesize that this immunomodulatory property of IL-12 will serve as a protective mechanism to preserve a population of stem cells under inflammatory conditions.
Triple Antibiotic Polymer Nanofibers for Intracanal Drug Delivery: Effects on Dual Species Biofilm and Cell Function.Saturday, September 24, 2016
Pankajakshan D, Albuquerque MT, Evans JD, Kamocka MM, Gregory RL, Bottino MC,
Journal of endodontics. Oct-2016
Triple antibiotic-containing polymer nanofibers led to significant bacterial death, whereas they did not affect DPSC attachment and proliferation on dentin.
Identification of keratin19-positive cancer stem cells associating human hepatocellular carcinoma using 18F-fluorodeoxyglucose positron emission tomography.Saturday, September 24, 2016
Kawai T, Yasuchika K, Seo S, Higashi T, Ishii T, Miyauchi Y, Kojima H, Yamaoka R, Katayama H, Yoshitoshi EY, Ogiso S, Kita S, Yasuda K, Fukumitsu K, Nakamoto Y, Hatano E, Uemoto S,
Clinical cancer research : an official journal of the American Association for Cancer Research. 23-Sep-2016
Purpose The current lack of tools for easy assessment of cancer stem cells (CSCs) prevents the development of therapeutic strategies for hepatocellular carcinoma (HCC). We previously reported that keratin 19 (K19) is a novel HCC-CSC marker, and that positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) is an effective method for predicting postoperative outcome in HCC. Herein, we examined whether K19+ HCC-CSCs can be tracked using 18F-FDG-PET. Experimental Design K19 and glucose transporter-1 (GLUT1) expression was evaluated by immunohistochemistry in 98 HCC patients who underwent 18F-FDG-PET scans before primary tumor resection. Standardized uptake values (SUV) for primary tumors and tumor-to-nontumor SUV ratios (TNR) were calculated using FDG accumulation levels, and values were compared among K19+/K19- patients. Using HCC cell lines encoding with a K19 promoter-driven enhanced green fluorescence protein, 18F-FDG uptake and GLUT1 expression were examined in fluorescence-activated cell sorting (FACS)-isolated K19+/K19- cells. Results In HCC patients, K19 expression was significantly correlated with GLUT1 expression and FDG accumulation. Receiver operating characteristic analyses revealed that, among preoperative clinical factors, TNR was the most sensitive indicator of K19 expression in HCC tumors. In HCC cells, FACS-isolated K19+ cells displayed significantly higher 18F-FDG uptake than K19- cells. Moreover, gain/loss of function experiments confirmed that K19 regulates 18F-FDG uptake through transforming growth factor beta (TGFb)/Smad signaling including Sp1 and its downstream target GLUT1. Conclusion 18F-FDG-PET can be used to predict K19 expression in HCC, and should thereby aid in the development of novel therapeutic strategies targeting K19+ HCC-CSCs.
Postoperative Delirium Following Orthognathic Surgery in a Young Patient.Saturday, September 24, 2016
da Costa FH, Herrera PA, Pereira-Stabile CL, Vitti Stabile GA,
Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 27-Aug-2016
Delirium is an organic mental syndrome with acute onset characterized by diffuse brain dysfunction and neural activity disorganization. It is usually related to cognition and perception changes, decreased level of consciousness, and disorganization of thoughts that are unrelated to previous dementia. Occurrence is more frequent in patients with previous degenerative disease and elderly patients, especially those older than 85 years. Although the pathophysiology is not totally known, studies have shown that, among the main factors that lead to delirium, the drugs used for general anesthesia induction are the most relevant (hypnotics, anticholinergic drugs, and H2 receptor blockers), especially those used in long surgical procedures. This report describes the case of a 24-year-old woman with a noncontributory medical and psychological history. She underwent bimaxillary orthognathic surgery with a total general anesthesia time of 7 hours. Postoperatively, she developed agitation, confusion, and delirium. After a psychiatry consult and discussion with the anesthesia team, the diagnosis of psychotic break owing to late postoperative delirium was established.
Mice engrafted with human hematopoietic stem cells supports a human myeloid cell inflammatory response in vivo.Saturday, September 24, 2016
Baird A, Deng C, Eliceiri M, Haghi F, Dang X, Coimbra R, Costantini TW, Torbett BE, Eliceiri BP,
Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society. 24-Sep-2016
Mice engrafted with human CD34(+) hematopoietic stem and progenitor cells (CD34(+) -HSPCs) have been used to study human infection, diabetes, sepsis and burn, suggesting that they could be highly amenable to characterizing the human inflammatory response to injury. To this end, we analyzed human leukocytes infiltrating subcutaneous implants of polytetrafluoroethylene (PVA) sponges in immunodeficient NSG mice reconstituted with CD34(+) -HSPCs. We report that human CD45(+) (hCD45(+) ) leukocytes were present in PVA sponges 3 and 7 days post-implantation and could be localized within the sponges by immunohistochemistry. The different CD45(+) sub-types were characterized by flow cytometry and the profile of human cytokines they secreted into PVA wound fluid was assessed using a human-specific multiplex bead analyses of human IL-12p70, TNFα, IL-10, IL-6, IL1β, and IL-8. This enabled tracking the functional contributions of HLA-DR(+) , CD33(+) , CD19(+) , CD62L(+) , CD11b(+) or CX3CR1(+) hCD45(+) infiltrating inflammatory leukocytes. PCR of cDNA prepared from these cells enabled the assessment and differentiation of human, mouse and uniquely human genes. These findings support the hypothesis that mice engrafted with CD34(+) -HSPCs can be deployed as precision avatars to study the human inflammatory response to injury. This article is protected by copyright. All rights reserved.
Correlation of HIF-1α/HIF-2α expression with FDG uptake in lung adenocarcinoma.Saturday, September 24, 2016
Higashi K, Yamagishi T, Ueda Y, Ishigaki Y, Shimasaki M, Nakamura Y, Oguchi M, Takegami T, Sagawa M, Tonami H,
Annals of nuclear medicine. 23-Sep-2016
FDG uptake correlated more significantly with HIF-2α expression than with HIF-1α expression, and both FDG uptake and HIF-2α expression, but not HIF-1α expression was correlated with post-operative recurrence in the patients with lung adenocarcinoma. These results suggest that both FDG uptake and HIF-2α expression may represent a more aggressive phenotype and that HIF-2α may play a more important role than HIF-1α in the uptake of FDG in lung adenocarcinoma.
Efficacy of allogeneic mesenchymal stem cell administration in a model of acute ischemic kidney injury in cats.Saturday, September 24, 2016
Rosselli DD, Mumaw JL, Dickerson V, Brown CA, Brown SA, Schmiedt CW,
Research in veterinary science. Oct-2016
This study did not support the use of allogeneic MSCs in AKI in the regimen described here. Type of renal injury, MSC dose, allogenicity, duration, and route or timing of administration could influence the efficacy MSCs.
Anticholinergic drug burden in non-cancer vs. cancer patients near the end of life.Saturday, September 24, 2016
Hochman MJ, Kamal AH, Wolf S, Samsa GP, Currow DC, Abernethy AP, LeBlanc TW,
Journal of pain and symptom management. 20-Sep-2016
ACL is associated with worse fatigue and QOL, and may not differ significantly between cancer and non-cancer patients nearing end of life. SM drugs are more responsible for ACL in cancer and non-cancer patients, though DM drugs contribute significantly to ACL in the latter group. We recommend more attention to reducing anticholinergic use in all patients with life-limiting illness.
Concise Review: Lessons from Naïve Human Pluripotent Cells.Saturday, September 24, 2016
Ware CB,
Stem cells (Dayton, Ohio). 24-Sep-2016
The naïve state of pluripotency is actively being explored by a number of labs. There is some controversy in the field as to the true identity of naïve human pluripotent cells as they are not exact mirrors of the mouse. The various reports published, though in basic agreement, present discrepancies in the characterization of the various lines, which likely reflect the etiology of these lines. The primary lesson learned from these contributions is that a human naïve state reflecting the pre-implantation human is likely to exist. The essential factors that will universally maintain the naïve state in human cells in vitro are not yet fully understood. These first need to be identified in order to describe the definitive characteristics of this state. Comparisons of naïve and primed human pluripotent cells have also highlighted consistencies between states and broadened our understanding of embryonic metabolism, epigenetic change required for development, embryonic DNA repair strategies and embryonic expression dynamics. This article is protected by copyright. All rights reserved.
Neuroprotective effect of mesenchymal stem cell through complement component 3 downregulation after transient focal cerebral ischemia in mice.Saturday, September 24, 2016
Jung HS, Jeong SY, Yang J, Kim SD, Zhang B, Yoo HS, Song SU, Jeon MS, Song YS,
Neuroscience letters. 20-Sep-2016
Bone marrow-derived mesenchymal stem cells (MSCs) are used in stroke treatment despite the poor understanding of its mode of action. The immune suppressive and anti-inflammatory properties of MSCs possibly play important roles in regulating neuroinflammation after stroke. We investigated whether MSCs reduce the inflammatory complement component 3 (C3) levels, thus, providing neuroprotection during stroke. Mice were subjected to transient focal cerebral ischemia (tFCI), after which MSCs were intravenously injected. The infarct volume of the brain was reduced in MSC-injected tFCI mice, and C3 expression was significantly reduced in both the brain and the blood. Additionally, the profiles of other inflammatory mediators demonstrated neuroprotective changes in the MSCs-treated group. In order to analyze the effect of MSCs on neurons during cerebral ischemia, primary cortical neurons were co-cultured with MSCs under oxygen-glucose deprivation (OGD). Primary neurons co-cultured with MSCs exhibited reduced levels of C3 expression and increased protection against OGD, indicating that treatment with MSCs reduces excessive C3 expression and rescues ischemia-induced neuronal damage. Our finding suggests that reduction of C3 expression by MSCs can help to ameliorate ischemic brain damage, offering a new neuroprotective strategy in stroke therapy.
CRISPR/Cas9 Genome Editing in Embryonic Stem Cells.Saturday, September 24, 2016
Andrey G, Spielmann M,
Methods in molecular biology (Clifton, N.J.). 2017
Targeted mutagenesis is required to evaluate the function of DNA segments across the genome. In recent years the CRISPR/Cas9 technology has been widely used for functional genome studies and is partially replacing classical homologous recombination methods in different aspects. CRISPR/Cas9-derived tools indeed allow the production of a wide-range of engineered mutations: from point mutations to large chromosomal rearrangements such as deletions, duplications and inversions. Here we present a protocol to engineer Embryonic Stem Cells (ESC) with desired mutations using transfection of custom-made CRISPR/Cas9 vectors. These methods allow the in vivo modeling of congenital mutations and the functional interrogation of DNA sequences.
Advanced glycation endproducts impair endothelial progenitor cell migration and homing via syndecan 4 shedding.Saturday, September 24, 2016
Xie J, Li R, Wu H, Chen J, Li G, Chen Q, Wei Z, He G, Wang L, Ferro A, Xu B,
Stem cells (Dayton, Ohio). 24-Sep-2016
Endothelial progenitor cells (EPCs) are a subtype of bone marrow-derived progenitor cells. Stromal cell-derived factor 1 (SDF-1)-mediated EPC mobilization from bone marrow to areas of ischemia plays an important role in angiogenesis. Previous studies have reported that advanced glycation endproducts (AGEs), which are important mediators of diabetes-related vascular pathology, may impair EPC migration and homing, but the mechanism is unclear. Syndecan-4 (synd4) is a ubiquitous heparan sulfate proteoglycan receptor on the cell surface, involved in SDF-1-dependent cell migration. The extracellular domain of synd4 (ext-synd4) is shed in the context of acute inflammation, but the shedding of ext-synd4 in response to AGEs is undefined. Here we investigated changes in ext-synd4 on EPCs in response to AGEs, focusing on the influence of impaired synd4 signaling on EPC migration and homing. We found decreased full length and increased residue of synd4 in cells incubated with AGEs, with concomitant increase in the soluble fragment of ext-synd4 in the cell medium. EPCs from patients with type 2 diabetes expressed less ext-synd4 as assessed by western blotting. Flow cytometry analysis showed less ext-synd4 on circulating CD34(+) PMNCs, of which EPCs form a subgroup. We then explored the role of synd4 in EPC migration and homing. Impaired migration of synd4-deficient EPCs was observed by a 2D-chemotaxis slide. Furthermore, poor homing of synd4-/- EPCs was observed in a mouse model of lower limb ischemia. This study demonstrates that the shedding of synd4 from EPCs plays a key role in AGE-mediated dysfunction of EPC migration and homing. This article is protected by copyright. All rights reserved.
Dual effect of F-actin targeted carrier combined with antimitotic drug on aggressive colorectal cancer cytoskeleton: Allying dissimilar cell cytoskeleton disrupting mechanisms.Saturday, September 24, 2016
Taranejoo S, Janmaleki M, Pachenari M, Seyedpour SM, Chandrasekaran R, Cheng W, Hourigan K,
International journal of pharmaceutics. 20-Sep-2016
A recent approach to colon cancer therapy is to employ selective drugs with specific extra/intracellular sites of action. Alteration of cytoskeletal protein reorganization and, subsequently, to cellular biomechanical behaviour during cancer progression highly affects the cancer cell progress. Hence, cytoskeleton targeted drugs are an important class of cancer therapy agents. We have studied viscoelastic alteration of the human colon adenocarcinoma cell line, SW48, after treatment with a drug delivery system comprising chitosan as the carrier and albendazole as the microtubule-targeting agent (MTA). For the first time, we have evaluated the biomechanical characteristics of the cell line, using the micropipette aspiration (MA) method after treatment with drug delivery systems. Surprisingly, employing a chitosan-albendazole pair, in comparison with both neat materials, resulted in more significant change in the viscoelastic parameters of cells, including the elastic constants (K1 and K2) and the coefficient of viscosity (μ). This difference was more pronounced for cancer cells after 48h of the treatment. Microtubule and actin microfilament (F-actin) contents in the cell line were studied by immunofluorescent staining. Good agreement was observed between the mechanical characteristics results and microtubule/F-actin contents of the treated SW48 cell line, which declined after treatment. The results showed that chitosan affected F-actin more, while MTA was more effective for microtubules. Toxicity studies were performed against two cancer cell lines (SW48 and MCF10CA1h) and compared to normal cells, MCF10A. The results showed cancer selectiveness, safety of formulation, and enhanced anticancer efficacy of the CS/ABZ conjugate. This study suggests that employing such a suitable pair of drug-carriers with dissimilar sites of action, thus allying the different cell cytoskeleton disrupting mechanisms, may provide a more efficient cancer therapy approach.
Role of VR1 in the differentiation of bone marrow-derived mesenchymal stem cells into cardiomyocytes associated with Wnt/β-catenin signaling.Friday, September 23, 2016
Ren M, Wang T, Huang L, Ye X, Xv Z, Ouyang C, Han Z,
Cardiovascular therapeutics. 23-Sep-2016
To summarize, our data demonstrate important role of VR1 in BMSCs differentiation into cardiomyocytes in conjunction of Wnt/β-catenin signaling. This article is protected by copyright. All rights reserved.
Safety and immunogenicity of a live attenuated pentavalent rotavirus vaccine in HIV-exposed infants with or without HIV infection in Africa.Friday, September 23, 2016
Levin MJ, Lindsey JC, Kaplan SS, Schimana W, Lawrence J, McNeal MM, Bwakura-Dangarembizi M, Ogwu A, Mpabalwani EM, Sato P, Siberry G, Nelson M, Hille D, Weinberg GA, Weinberg A,
AIDS (London, England). 20-Sep-2016
RV5 was immunogenic in both HIV+ and HEU infants and no safety signals were observed.
Nano-Cesium for Anti-Cancer Properties: An Investigation into Cesium Induced Metabolic Interference.Friday, September 23, 2016
Daza EA, Misra SK, Schwartz-Duval AS, Ohoka A, Miller C, Pan D,
ACS applied materials & interfaces. 23-Sep-2016
The use of cesium chloride (CsCl) for cancer therapy ("high pH therapy") has been theorized to produce anti-cancer properties by raising intracellular pH to induce apoptosis. Although considered as "alternative medicine", little scientific evidence supports this theory. Alternatively, cells have no cesium ion (Cs+) mediated channels for clearance. Thus, such unstable electrochemical distributions have the potential severe potential to disrupt electrochemical dependent cellular processes, such as glucose co-transporters. Hence, a detailed investigation of pH changing effects and glucose uptake inhibition are warranted as a possible cesium-induced anti-cancer therapy. We developed and characterized cesium nanoparticles (38 ± 6 nm), termed NanoCs, for nanoparticle-mediated internalization of the ion, and compared its treatment to free CsCl. Our investigations suggest that neither NanoCs nor CsCl drastically changed the intracellular pH, negating the theory. Alternatively, NanoCs lead to a significant decrease in glucose uptake when compared to free CsCl, suggesting cesium inhibited glucose uptake. An apoptosis assay of observed cell death affirms that NanoCs leads tumor cells to initiate apoptosis rather than follow necrotic behavior. Furthermore, NanoCs lead to in vivo tumor regression, where H&E analysis confirmed apoptotic cell populations. Thus, NanoCs persuaded pH-independent anti-cancer therapy by inducing metabolic stasis.
Tissue-Specific Stem Cells Obtained by Reprogramming of Non-Obese Diabetic (NOD) Mouse-Derived Pancreatic Cells Confer Insulin Production in Response to Glucose.Friday, September 23, 2016
Saitoh I, Sato M, Soda M, Inada E, Iwase Y, Murakami T, Ohshima H, Hayasaki H, Noguchi H,
PloS one. 23-9-2016
Type 1 diabetes occurs due to the autoimmune destruction of pancreatic β-cells in islets. Transplantation of islets is a promising option for the treatment of patients with type 1 diabetes that experience hypoglycemic unawareness despite maximal care, but the present shortage of donor islets hampers such transplantation. Transplantation of insulin-producing cells derived from the patients themselves would be one of the most promising approaches to cure type 1 diabetes. Previously, we demonstrated that insulin-producing cells could be produced by transfecting murine pancreatic cells with Yamanaka's reprogramming factors. Non-obese diabetic (NOD) mice are naturally occurring mutant mice defective in insulin production due to autoimmune ablation of pancreatic β-cells. In this study, we showed that glucose-sensitive insulin-producing cells are successfully generated by transfecting primary pancreatic cells from NOD mice (aged 6 months old) with a plasmid harboring the cDNAs for Oct-3/4, Sox2, Klf4, and c-Myc. Transfection was repeated 4 times in a 2 day-interval. Sixty-five days after final transfection, cobblestone-like colonies appeared. They proliferated in vitro and expressed pluripotency-related genes as well as Pdx1, a transcription factor specific to tissue-specific stem cells for the β-cell lineage. Transplantation of these cells into nude mice failed to produce teratoma unlike induced pluripotent stem cells (iPSCs). Induction of these cells to the pancreatic β-cell lineage demonstrated their capability to produce insulin in response to glucose. These findings suggest that functional pancreatic β-cells can be produced from patients with type 1 diabetes. We call these resultant cells as "induced tissue-specific stem cells from the pancreas" (iTS-P) that could be valuable sources of safe and effective materials for cell-based therapy in type 1 diabetes.
TRAP1 regulates stemness through Wnt/β-catenin pathway in human colorectal carcinoma.Friday, September 23, 2016
Lettini G, Sisinni L, Condelli V, Matassa DS, Simeon V, Maddalena F, Gemei M, Lopes E, Vita G, Del Vecchio L, Esposito F, Landriscina M,
Cell death and differentiation. 23-Sep-2016
Colorectal carcinoma (CRC) is a common cause of cancer-related death worldwide. Indeed, treatment failures are triggered by cancer stem cells (CSCs) that give rise to tumor repopulation upon initial remission. Thus, the role of the heat shock protein TRAP1 in stemness was investigated in CRC cell lines and human specimens, based on its involvement in colorectal carcinogenesis, through regulation of apoptosis, protein homeostasis and bioenergetics. Strikingly, co-expression between TRAP1 and stem cell markers was observed in stem cells located at the bottom of intestinal crypts and in CSCs sorted from CRC cell lines. Noteworthy, TRAP1 knockdown reduced the expression of stem cell markers and impaired colony formation, being the CSC phenotype and the anchorage-independent growth conserved in TRAP1-rich cancer cells. Consistently, the gene expression profiling of HCT116 cells showed that TRAP1 silencing results in the loss of the stem-like signature with acquisition of a more-differentiated phenotype and the downregulation of genes encoding for activating ligands and target proteins of Wnt/β-catenin pathway. Mechanistically, TRAP1 maintenance of stemness is mediated by the regulation of Wnt/β-catenin signaling, through the modulation of the expression of frizzled receptor ligands and the control of β-catenin ubiquitination/phosphorylation. Remarkably, TRAP1 is associated with higher expression of β-catenin and several Wnt/β-catenin target genes in human CRCs, thus supporting the relevance of TRAP1 regulation of β-catenin in human pathology. This study is the first demonstration that TRAP1 regulates stemness and Wnt/β-catenin pathway in CRC and provides novel landmarks in cancer biology and therapeutics.Cell Death and Differentiation advance online publication, 23 September 2016; doi:10.1038/cdd.2016.67.
Cellular Functions and Gene and Protein Expression Profiles in Endothelial Cells Derived from Moyamoya Disease-Specific iPS Cells.Friday, September 23, 2016
Hamauchi S, Shichinohe H, Uchino H, Yamaguchi S, Nakayama N, Kazumata K, Osanai T, Abumiya T, Houkin K, Era T,
PloS one. 23-9-2016
Downregulation of ECM receptor-related genes may be associated with impaired angiogenic activity in ECs derived from iPSCs from patients with MMD. Upregulation of splicing regulation-related proteins implied differences in splicing patterns between control and MMD ECs.
Overexpression of Glutamate Decarboxylase in Mesenchymal Stem Cells Enhances Their Immunosuppressive Properties and Increases GABA and Nitric Oxide Levels.Friday, September 23, 2016
Urrutia M, Fernández S, González M, Vilches R, Rojas P, Vásquez M, Kurte M, Vega-Letter AM, Carrión F, Figueroa F, Rojas P, Irarrázabal C, Fuentealba RA,
PloS one. 23-9-2016
The neurotransmitter GABA has been recently identified as a potent immunosuppressive agent that targets both innate and adaptive immune systems and prevents disease progression of several autoimmunity models. Mesenchymal stem cells (MSCs) are self-renewing progenitor cells that differentiate into various cell types under specific conditions, including neurons. In addition, MSC possess strong immunosuppressive capabilities. Upon cytokine priming, undifferentiated MSC suppress T-cell proliferation via cell-to-cell contact mechanisms and the secretion of soluble factors like nitric oxide, prostaglandin E2 and IDO. Although MSC and MSC-derived neuron-like cells express some GABAergic markers in vitro, the role for GABAergic signaling in MSC-mediated immunosuppression remains completely unexplored. Here, we demonstrate that pro-inflammatory cytokines selectively regulate GAD-67 expression in murine bone marrow-MSC. However, expression of GAD-65 is required for maximal GABA release by MSC. Gain of function experiments using GAD-67 and GAD-65 co-expression demonstrates that GAD increases immunosuppressive function in the absence of pro-inflammatory licensing. Moreover, GAD expression in MSC evokes an increase in both GABA and NO levels in the supernatants of co-cultured MSC with activated splenocytes. Notably, the increase in NO levels by GAD expression was not observed in cultures of isolated MSC expressing GAD, suggesting crosstalk between these two pathways in the setting of immunosuppression. These results indicate that GAD expression increases MSC-mediated immunosuppression via secretion of immunosuppressive agents. Our findings may help reconsider GABAergic activation in MSC for immunological disorders.
Individualized medicine using intestinal responses to CFTR potentiators and correctors.Friday, September 23, 2016
Beekman JM,
Pediatric pulmonology. Oct-2016
Cystic fibrosis transmembrane conductance regulator (CFTR) modulators that target the mutant CFTR protein are being introduced for treatment of cystic fibrosis. Stratification of subjects based on their CFTR genotype has been proven essential to demonstrate clinical efficacy of these novel treatments. Despite this stratification, considerable heterogeneity between subjects receiving CFTR modulators is still observed which remains largely uncharacterized. The CFTR genotype, and additional genetic and environmental factors that impact either tissue-specific CFTR protein characteristics or the pharmacokinetic properties of treatments will likely determine the individual response to therapy. The development of intestinal biomarkers for CFTR modulators may help to better quantitate individual responses to treatment, with potential to optimize treatments for subjects with limited responses, and the selection of responsive subjects that currently do not receive treatments. Here, recent advances concerning the use of intestinal biomarkers for CFTR modulator treatments are reviewed, with a focus on biomarkers of CFTR function in ex vivo rectal biopsies and in vitro cultured primary intestinal organoids. Their potential value is considered in the context of the current unmet needs for better treatments for the majority of subjects with CF, and individual biomarkers that enable the prediction of long term therapeutic responses to CFTR modulators. Pediatr Pulmonol. 2016;51:S23-S34. © 2016 Wiley Periodicals, Inc.
Inheritable Silencing of Endogenous Genes by Hit-and-Run Targeted Epigenetic Editing.Saturday, September 24, 2016
Amabile A, Migliara A, Capasso P, Biffi M, Cittaro D, Naldini L, Lombardo A,
Cell. 22-Sep-2016
Gene silencing is instrumental to interrogate gene function and holds promise for therapeutic applications. Here, we repurpose the endogenous retroviruses' silencing machinery of embryonic stem cells to stably silence three highly expressed genes in somatic cells by epigenetics. This was achieved by transiently expressing combinations of engineered transcriptional repressors that bind to and synergize at the target locus to instruct repressive histone marks and de novo DNA methylation, thus ensuring long-term memory of the repressive epigenetic state. Silencing was highly specific, as shown by genome-wide analyses, sharply confined to the targeted locus without spreading to nearby genes, resistant to activation induced by cytokine stimulation, and relieved only by targeted DNA demethylation. We demonstrate the portability of this technology by multiplex gene silencing, adopting different DNA binding platforms and interrogating thousands of genomic loci in different cell types, including primary T lymphocytes. Targeted epigenome editing might have broad application in research and medicine.
An increased expression profile of Th9/IL-9 correlated with Th17/IL-17 in patients with immune thrombocytopenia.Friday, September 23, 2016
Qiao J, Li X, Wu Y, Wu X, Zhu F, Liu N, Qi K, Cheng H, Li D, Sun H, Zeng L, Xu K,
Platelets. 23-Sep-2016
Immune thrombocytopenia (ITP) is a heterogeneous autoimmune disease, characterized by dysregulation of cellular immunity. Th9 cells were recently identified as a new subtype of Th cells, characterized by preferential production of IL-9. Given the pleiotropic function of IL-9, Th9 cells are demonstrated to be involved in various autoimmune diseases. However, whether Th9 cells are involved in the pathogenesis of ITP remains unclear. In this study, 49 active ITP patients, 39 ITP with remission and 20 healthy controls were included. Peripheral blood mononuclear cells (PBMCs) were isolated from ITP and controls for measuring Th9 and Th17 cells by flow cytometry. Meanwhile, RNA was isolated from PBMCs for the measurement of the mRNA level of PU.1, IRF4, BATF, and RORγt by quantitative real-time PCR. Plasma levels of IL-9 and IL-17 were detected by ELISA. Our results showed that higher expressions of Th9, IL-9, and associated transcription factors (PU.1, IRF4, and BATF) were found in active ITP patients and restored to the normal level (except IL-9) in patients in remission. Meanwhile, Th9 cells and the IL-9 plasma level were positively correlated with Th17 cells and the IL-17 level in ITP patients, respectively. Moreover, a positive correlation of IRF4 or BATF with RORγt was found. In conclusion, an aberrant expression profile of Th9/IL-9 was associated with pathogenesis of ITP possibly through cooperatively working with Th17/IL-17 and therapeutically targeting Th9/IL-9 might be a novel approach in the treatment of ITP.
Comprehensive Review on the Use of Graphene Based Substrates for Regenerative Medicine and Biomedical Devices.Friday, September 23, 2016
Kumar S, Chatterjee K,
ACS applied materials & interfaces. 23-Sep-2016
Owing to its extraordinary properties, recent research suggests that graphene holds great potential in the biomedical field. Whereas initial attempts focused on the use of suspended graphene for drug delivery and bioimaging, more recent work has demonstrated its advantages for preparing substrates for tissue engineering, and biomedical devices and products. Cells are known to interact with and respond to nanoparticles differently when presented in the form of a substrate than in the form of a suspension. In tissue engineering, a stable and supportive substrate or scaffold is needed to provide mechanical support, chemical stimuli and biological signals to cells. This review compiles recent advances of the impact of both graphene and graphene-derived particles to prepare supporting substrates for tissue regeneration and devices as well as the associated cell response to multifunctional graphene substrates. We discuss the interaction of cells with pristine graphene, graphene oxide, functionalized graphene, and hybrid graphene particles in the form of coatings and composites. Such materials show excellent biological outcomes in vitro, in particular for, orthopedic and neural tissue engineering applications. Preliminary evaluation of these graphene based materials in vivo reinforces their promise for tissue regeneration and implants. Although the reported findings of studies on graphene based substrates are promising, several questions and concerns associated with their in vivo use persist. Possible strategies to examine these issues are presented.
Splenic pooling and loss of VCAM-1 causes an engraftment defect in patients with myelofibrosis after allogeneic hematopoietic stem cell transplantation.Friday, September 23, 2016
Hart C, Klatt S, Barop J, Mueller G, Schelker R, Holler E, Huber E, Herr W, Grassinger J,
Haematologica. 4-Aug-2016
Myelofibrosis is a myeloproliferative neoplasm that results in cytopenia, bone marrow fibrosis and extramedullary hematopoiesis. Allogeneic hematopoietic stem cell transplantation is the only curative treatment but is associated with a risk of delayed engraftment and graft failure. In this study patients with myelofibrosis (n=31) and acute myeloid leukemia (n=31) were analyzed for time to engraftment, graft failure and engraftment related factors. Early and late neutrophil engraftment and late thrombocyte engraftment was significantly delayed in patients with myelofibrosis as compared to acute myeloid leukemia and graft failure only occurred in myelofibrosis (6%). Only spleen size had a significant influence on engraftment efficiency in myelofibrosis patients. To analyze the cause for the engraftment defect clearance of hematopoietic stem cells from peripheral blood was measured and immunohistological staining of bone marrow sections was performed. Numbers of circulating CD34+ were significantly reduced at early time points in myelofibrosis patients, whereas CD34+CD38- and colony-forming cells showed no significant difference in clearance. Staining of bone marrow sections for homing proteins revealed a loss of VCAM-1 in myelofibrosis. This was mirrored by a significant increased level of soluble VCAM-1 within the peripheral blood. In conclusion, our data suggest that reduced engraftment and graft failure in myelofibrosis patients is caused by an early pooling of CD34+ hematopoietic stem cells in the spleen and a bone marrow homing defect caused by the loss of VCAM-1. Improved engraftment in myelofibrosis might be achieved by approaches that reduce spleen size and cleavage of VCAM-1 in these patients prior to hematopoietic stem cell transplantation.
The Department of Defense at the Forefront of a Global Health Emergency Response: Lessons Learned from the Ebola Outbreak.Saturday, September 24, 2016
Diehl G, Bradstreet N, Monahan F,
Health security. 4-8-2016
Tasked with analyzing the effectiveness of the Department of Defense's (DoD's) global health engagements, the Uniformed Services University of the Health Sciences (USU) used the Measures Of Effectiveness in Defense Engagement and Learning (MODEL) study to conduct a qualitative analysis of the DoD's response efforts to the Ebola pandemic in West Africa. The research aims to summarize the findings of studies that monitor and evaluate the DoD's response to the Ebola pandemic or compare the effectiveness of different DoD response activities; it further aims to identify common themes around positive and negative lessons learned and recommendations that can be applied to future DoD humanitarian assistance and disaster response efforts. The search included documents and observations from PubMed, Disaster Lit: Resource Guide for Disaster Medicine and Public Health, the Joint Lessons Learned Information System, the DoD and US Africa Command websites, and Google Scholar. The records selected from the search were analyzed to provide insights on the DoD's humanitarian assistance and disaster response engagements that could be employed to inform future operations and policy. Furthermore, the research identifies strengths and gaps in military capabilities to respond to disasters, which can be used to inform future training and education courses. Overall, the findings demonstrate the importance of monitoring, evaluating, and assessing disaster response activities and provide new evidence to support the implementation of activities, in accordance with the Global Health Security Agenda, to strengthen all-threat prevention, detection, and response capabilities worldwide.
A novel optical microscope for imaging large embryos and tissue volumes with sub-cellular resolution throughout.Friday, September 23, 2016
McConnell G, Trägårdh J, Amor R, Dempster J, Reid E, Amos WB,
eLife. 24-9-2016
Current optical microscope objectives of low magnification have low numerical aperture and therefore have too little depth resolution and discrimination to perform well in confocal and nonlinear microscopy. This is a serious limitation in important areas, including the phenotypic screening of human genes in transgenic mice by study of embryos undergoing advanced organogenesis. We have built an optical lens system for 3D imaging of objects up to 6 mm wide and 3 mm thick with depth resolution of only a few microns instead of the tens of microns currently attained, allowing sub-cellular detail to be resolved throughout the volume. We present this lens, called the Mesolens, with performance data and images from biological specimens including confocal images of whole fixed and intact fluorescently-stained 12.5-day old mouse embryos.
Imaging far and wide.Friday, September 23, 2016
Chhetri RK, Keller PJ,
eLife. 23-9-2016
A custom-built objective lens called the Mesolens allows relatively large biological specimens to be imaged with cellular resolution.
Hypoglycemia Enhances Epithelial-Mesenchymal Transition and Invasiveness, and Restrains the Warburg Phenotype, in Hypoxic HeLa Cell Cultures and Microspheroids.Friday, September 23, 2016
Marín-Hernández Á, Gallardo-Pérez JC, Hernández-Reséndiz I, Del Mazo-Monsalvo I, Robledo-Cadena DX, Moreno-Sánchez R, Rodríguez-Enríquez S,
Journal of cellular physiology. 23-Sep-2016
The accelerated growth of solid tumors leads to episodes of both hypoxia and hypoglycemia (HH) affecting their intermediary metabolism, signal transduction and transcriptional activity. A previous study showed that normoxia (20% O2 ) plus 24 h hypoglycemia (2.5 mM glucose) increased glycolytic flux whereas oxidative phosphorylation (OxPhos) was unchanged vs. normoglycemia in HeLa cells. However, the simultaneous effect of HH on energy metabolism has not been yet examined. Therefore, the effect of hypoxia (0.1-1% O2 ) plus hypoglycemia on the energy metabolism of HeLa cells was analyzed by evaluating protein content and activity, along with fluxes of both glycolysis and OxPhos. Under hypoxia, in which cell growth ceased and OxPhos enzyme activities, ΔΨm and flux were depressed, hypoglycemia did not stimulate glycolytic flux despite increasing H-RAS, p-AMPK, GLUT1, GLUT3 and HKI levels, and further decreasing mitochondrial enzyme content. The impaired mitochondrial function in HH cells correlated with mitophagy activation. The depressed OxPhos and unchanged glycolysis pattern was also observed in quiescent cells from mature multicellular tumor spheroids, suggesting that these inner cell layers are similarly subjected to HH. The principal ATP supplier was glycolysis for HH 2D monolayer and 3D quiescent spheroid cells. Accordingly, the glycolytic inhibitors iodoacetate and gossypol were more effective than mitochondrial inhibitors in decreasing HH-cancer cell viability. Under HH, stem cell-, angiogenic-, and EMT-biomarkers, as well as glycoprotein-P content and invasiveness, were also enhanced. These observations indicate that HH cancer cells develop an attenuated Warburg and pronounced EMT- and invasive-phenotype. This article is protected by copyright. All rights reserved.
Intervertebral disc repair by allogeneic mesenchymal bone marrow cells: a randomized controlled trial.Friday, September 23, 2016
Noriega DC, Ardura F, Hernández-Ramajo R, Martín-Ferrero MA, Sánchez-Lite I, Toribio B, Alberca M, García V, Moraleda JM, Sánchez A, García-Sancho J,
Transplantation. 21-Sep-2016
Allogeneic MSC therapy may be a valid alternative for the treatment of DDD that is more logistically convenient than the autologous MSC treatment. The intervention is simple, does not require surgery, provides pain relief, and significantly improves disc quality.
Pask integrates hormonal signaling with histone modification via Wdr5 phosphorylation to drive myogenesis.Friday, September 23, 2016
Kikani CK, Wu X, Paul L, Sabic H, Shen Z, Shakya A, Keefe A, Villanueva C, Kardon G, Graves B, Tantin D, Rutter J,
eLife. 21-9-2016
PAS domain containing protein kinase (Pask) is an evolutionarily conserved protein kinase implicated in energy homeostasis and metabolic regulation across eukaryotic species. We now describe an unexpected role of Pask in promoting the differentiation of myogenic progenitor cells, embryonic stem cells and adipogenic progenitor cells. This function of Pask is dependent upon its ability to phosphorylate Wdr5, a member of several protein complexes including those that catalyze histone H3 Lysine 4 trimethylation (H3K4me3) during transcriptional activation. Our findings suggest that, during myoblast differentiation, Pask stimulates the conversion of repressive H3K4me1 to activating H3K4me3 marks on the promoter of the differentiation gene myogenin (Myog) via Wdr5 phosphorylation. This enhances accessibility of the MyoD transcription factor and enables transcriptional activation of the Myog promoter to initiate muscle differentiation. Thus, as an upstream kinase of Wdr5, Pask integrates signaling cues with the transcriptional network to regulate the differentiation of progenitor cells.
Phage Display Technology in Biomaterials Engineering: Progress and Opportunities for Applications in Regenerative Medicine.Friday, September 23, 2016
Martins IM, Reis RL, Azevedo HS,
ACS chemical biology. 23-Sep-2016
The field of regenerative medicine has been gaining momentum steadily over the past few years. The emphasis in regenerative medicine is to use various in-vitro and in-vivo approaches that leverage on the intrinsic healing mechanisms of the body to treat patients with disabling injuries and chronic diseases such as diabetes, osteoarthritis, and degenerative disorders of the cardiovascular and central nervous system. Phage display has been successfully employed to identify peptide ligands for a wide variety of targets, ranging from relatively small molecules (enzymes, cell receptors) to inorganic, organic, and biological (tissues) materials. Over the last two decades, phage display technology has advanced tremendously and has become a powerful tool in the most varied fields of research, including biotechnology, materials science, cell biology, pharmacology, and diagnostics. The growing interest in and success of phage display libraries is largely due its incredible versatility and practical use. This review discusses the potential of phage display technology in biomaterials engineering for applications in regenerative medicine.
Heterotopic Ossification: A Review of Current Understanding, Treatment, and Future.Friday, September 23, 2016
Edwards DS, Kuhn KM, Potter BK, Forsberg JA,
Journal of orthopaedic trauma. Oct-2016
Heterotopic ossification is the formation of bone at extraskeletal sites. The incidence of heterotopic ossification in military amputees from recent operations in Iraq and Afghanistan has been demonstrated to be as high as 65%. Heterotopic ossification poses problems to wound healing, rehabilitation, and prosthetic fitting. This article details the current evidence regarding its etiology, prevention, management, and research strategies.
Introduction.Friday, September 23, 2016
Stinner DJ, Fleming ME,
Journal of orthopaedic trauma. Oct-2016
Boundary cells restrict dystroglycan trafficking to control basement membrane sliding during tissue remodeling.Friday, September 23, 2016
McClatchey ST, Wang Z, Linden LM, Hastie EL, Wang L, Shen W, Chen A, Chi Q, Sherwood DR,
eLife. 23-Sep-2016
Epithelial cells and their underlying basement membranes (BMs) slide along each other to renew epithelia, shape organs, and enlarge BM openings. How BM sliding is controlled, however, is poorly understood. Using genetic and live cell imaging approaches during uterine-vulval attachment in C. elegans, we have discovered that the invasive uterine anchor cell activates Notch signaling in neighboring uterine cells at the boundary of the BM gap through which it invades to promote BM sliding. Through an RNAi screen, we found that Notch activation upregulates expression of ctg-1, which encodes a Sec14-GOLD protein and member of the Sec14 phosphatidylinositol-transfer protein superfamily that is implicated in vesicle trafficking. Through photobleaching, targeted knockdown, and cell-specific rescue, our results suggest that CTG-1 restricts BM adhesion receptor DGN-1 (dystroglycan) trafficking to the cell-BM interface, which promotes BM sliding. Together, these studies reveal a new morphogenetic signaling pathway that controls BM sliding to remodel tissues.
DAPK interacts with Patronin and the microtubule cytoskeleton in epidermal development and wound repair.Friday, September 23, 2016
Chuang M, Hsiao TI, Tong A, Xu S, Chisholm AD,
eLife. 23-Sep-2016
Epidermal barrier epithelia form a first line of defense against the environment, protecting animals against infection and repairing physical damage. In C. elegans, death-associated protein kinase (DAPK-1) regulates epidermal morphogenesis, innate immunity and wound repair. We find that DAPK-1 maintains epidermal tissue integrity through regulation of the microtubule (MT) cytoskeleton. dapk-1 epidermal phenotypes are suppressed by treatment with microtubule-destabilizing drugs and mimicked or enhanced by microtubule-stabilizing drugs. Loss of function in ptrn-1, the C. elegans member of the Patronin/Nezha/CAMSAP family of MT minus-end binding proteins, suppresses dapk-1 epidermal and innate immunity phenotypes. Over-expression of the MT-binding CKK domain of PTRN-1 triggers epidermal and immunity defects resembling those of dapk-1 mutants, and PTRN-1 localization is regulated by DAPK-1. DAPK-1 and PTRN-1 physically interact in co-immunoprecipitation experiments, and DAPK-1 itself undergoes MT-dependent transport. Our results uncover an unexpected interdependence of DAPK-1 and the microtubule cytoskeleton in maintenance of epidermal integrity.
MicroRNA-552 enhances metastatic capacity of colorectal cancer cells by targeting a disintegrin and metalloprotease 28.Friday, September 23, 2016
Wang J, Li H, Wang Y, Wang L, Yan X, Zhang D, Ma X, Du Y, Liu X, Yang Y,
Oncotarget. 21-Sep-2016
Colorectal cancer (CRC) is one of the most common prevalent cancer types worldwide. MicroRNAs (miRNAs or miRs) have been demonstrated to play crucial roles in the development, metastasis and drug resistance of CRC. In the present study, a strikingly elevated expression of miR-552 was determined in CRC tumor tissues and cells by a miRNA profiling analysis. Importantly, the gene of A Disintegrin And Metalloprotease (ADAM) family member 28 (ADAM28) was identified as a target of miR-552, which was further validated in terms of genetic dual luciferase report assay. Furthermore, an inhibition of miR-552 in LOVE and LS174T CRC cells by transducing miR-552 inhibitor (antagomiR-552) with a lentiviral vector exhibited an ability to reduce cell proliferation, migration and clonogenicity. Moreover, both LOVO and LS174T cells stably expressing miR-552 inhibitor displayed a decreased ability to develop tumors in a murine xenograft model in vivo. In contrast, a knockdown of ADAM28 by short hairpin RNA could reverse the antagomiR-552-induced inhibition of metastatic features of CRC cells in vitro. These results suggested that miR-552 is an oncomir able to promote CRC metastasis in part through a mechanism of targeting ADAM28, which may be a novel target for CRC treatment and warrants for further investigation.
Decreased Sperm Motility Retarded ICSI Fertilization Rate in Severe Oligozoospermia but Good-Quality Embryo Transfer Had Achieved the Prospective Clinical Outcomes.Friday, September 23, 2016
Zheng J, Lu Y, Qu X, Wang P, Zhao L, Gao M, Shi H, Jin X,
PloS one. 21-9-2016
The reduction of motile spermatozoa in severe oligozoospermia decreased the rates of fertilization and good-quality embryo. Obtaining and transfer of good-quality embryos was the good prognostic to achieve prospective clinical outcomes regardless of the severity of oligozoospermia.
BMP signaling and its paradoxical effects in tumorigenesis and dissemination.Friday, September 23, 2016
Zhang L, Ye Y, Long X, Xiao P, Ren X, Yu J,
Oncotarget. 20-Sep-2016
Bone morphogenetic proteins (BMPs) play important roles in embryonic and postnatal development by regulating cell differentiation, proliferation, motility, and survival, thus maintaining homeostasis during organ and tissue development. BMPs can lead to tumorigenesis and regulate cancer progression in different stages. Therefore, we summarized studies on BMP expression, the clinical significance of BMP dysfunction in various cancer types, and the molecular regulation of various BMP-related signaling pathways. We emphasized on the paradoxical effects of BMPs on various aspects of carcinogenesis, including epithelial-mesenchymal transition (EMT), cancer stem cells (CSCs), and angiogenesis. We also reviewed the molecular mechanisms by which BMPs regulate tumor generation and progression as well as potential therapeutic targets against BMPs that might be valuable in preventing tumor growth and invasion.
Astrocyte-produced leukemia inhibitory factor expands the neural stem/progenitor pool following perinatal hypoxia-ischemia.Friday, September 23, 2016
Felling RJ, Covey MV, Wolujewicz P, Batish M, Levison SW,
Journal of neuroscience research. 23-Sep-2016
Brain injuries, such as cerebral hypoxia-ischemia (H-I), induce a regenerative response from the neural stem/progenitors (NSPs) of the subventricular zone (SVZ); however, the mechanisms that regulate this expansion have not yet been fully elucidated. The Notch- Delta-Serrate-Lag2 (DSL) signaling pathway is considered essential for the maintenance of neural stem cells, but it is not known if it is necessary for the expansion of the NSPs subsequent to perinatal H-I injury. Therefore, the aim of this study was to investigate whether this pathway contributes to NSP expansion in the SVZ after H-I and, if so, to establish whether this pathway is directly induced by H-I or regulated by paracrine factors. Here we report that Notch1 receptor induction and one of its ligands, Delta-like 1, precedes NSP expansion after perinatal H-I in P6 rat pups and that this increase occurs specifically in the most medial cell layers of the SVZ where the stem cells reside. Pharmacologically inhibiting Notch signaling in vivo diminished NSP expansion. With an in vitro model of H-I, Notch1 was not induced directly by hypoxia, but was stimulated by soluble factors, specifically leukemia inhibitory factor, produced by astrocytes within the SVZ. These data confirm the importance both of the Notch-DSL signaling pathway in the expansion of NSPs after H-I and in the role of the support cells in their niche. They further support the body of evidence that indicates that leukemia inhibitory factor is a key injury-induced cytokine that is stimulating the regenerative response of the NSPs. © 2016 Wiley Periodicals, Inc.
Novel Function of Sprouty4 as a Regulator of Stemness and Differentiation of Embryonic Stem Cells.Friday, September 23, 2016
Lee JY, Park S, Kim KS, Ko JJ, Lee S, Kim KP, Park KS,
Development & reproduction. Jun-2016
Sprouty (Spry) genes encode inhibitors of the receptor tyrosine kinase signaling cascade, which plays important roles in stem cells. However, the role of Spry4 in the stemness of embryonic stem cells has not been fully elucidated. Here, we used mouse embryonic stem cells (mESCs) as a model system to investigate the role of Spry4 in the stem cells. Suppression of Spry4 expression results in the decreases of cell proliferation, EB formation and stemness marker expression, suggesting that Spry4 activity is associated with stemness of mESCs. Teratoma assay showed that the cartilage maturation was facilitated in Spry4 knocked down mESCs. Our results suggest that Spry4 is an important regulator of the stemness and differentiation of mESCs.
Rad51 Regulates Reprogramming Efficiency through DNA Repair Pathway.Friday, September 23, 2016
Lee JY, Kim DK, Ko JJ, Kim KP, Park KS,
Development & reproduction. Jun-2016
Rad51 is a key component of homologous recombination (HR) to repair DNA double-strand breaks and it forms Rad51 recombinase filaments of broken single-stranded DNA to promote HR. In addition to its role in DNA repair and cell cycle progression, Rad51 contributes to the reprogramming process during the generation of induced pluripotent stem cells. In light of this, we performed reprogramming experiments to examine the effect of co-expression of Rad51 and four reprogramming factors, Oct4, Sox2, Klf4, and c-Myc, on the reprogramming efficiency. Co-expression of Rad51 significantly increased the numbers of alkaline phosphatase-positive colonies and embryonic stem cell-like colonies during the process of reprogramming. Co-expression ofRad51 significantly increased the expression of epithelial markers at an early stage of reprogramming compared with control cells. Phosphorylated histone H2AX (γH2AX), which initiates the DNA double-strand break repair system, was highly accumulated in reprogramming intermediates upon co-expression of Rad51. This study identified a novel role of Rad51 in enhancing the reprogramming efficiency, possibly by facilitating mesenchymal-to-epithelial transition and by regulating a DNA damage repair pathway during the early phase of the reprogramming process.
Involvement of cAMP in the Human Serum-Induced Migration of Adipose-Derived Stem Cells.Friday, September 23, 2016
Lee M, Koh W, Kim B, Chung H, Cho G, Kim H,
Development & reproduction. Jun-2016
Previously we observed that human adipose-derived stem cells (hADSCs) could form aggregation during culture in the presence of human serum (HS). In the present study, we have examined if the aggregation might result from the cell migration and analyzed the difference of cell adhesivity after culture in various conditions. When cells were cultured in fetal bovine serum (FBS) alone, there was no morphological change. Similarly, cells pretreated with FBS for 1 day or cultured in a mixture of FBS and HS showed little change. In contrast, cells cultured in HS alone exhibited formation of cell-free area (spacing) and/or cell aggregation. When cells cultured in FBS or pretreated with FBS were treated with 0.06% trypsin, almost cells remained attached to the dish surfaces. In contrast, when cells cultured in HS alone were examined, most cells detached from the dish by the same treatment. Treatment of cells with forskolin, isobutylmethyl xanthine (IBMX) or LY294002 inhibited the formation of spacing whereas H89 or Y27632 showed little effect. When these cells were treated with 0.06% trypsin after culture, most cells detached from the dishes as cells cultured in HS alone did. However, cells treated with IBMX exhibited weaker adhesivity than HS alone. Based on these observations, it is suggested that HS treatment might decrease the adhesivity and induce three-dimensional migration of hADSCs, in the latter of which cAMP signaling could be involved.
Endothelial and circulating C19MC microRNAs are biomarkers of infantile hemangioma.Friday, September 23, 2016
Strub GM, Kirsh AL, Whipple ME, Kuo WP, Keller RB, Kapur RP, Majesky MW, Perkins JA,
JCI insight. 2016
Infantile hemangioma (IH) is the most common vascular tumor of infancy, and it uniquely regresses in response to oral propranolol. MicroRNAs (miRNAs) have emerged as key regulators of vascular development and are dysregulated in many disease processes, but the role of miRNAs in IH growth has not been investigated. We report expression of C19MC, a primate-specific megacluster of miRNAs expressed in placenta with rare expression in postnatal tissues, in glucose transporter 1-expressing (GLUT-1-expressing) IH endothelial cells and in the plasma of children with IH. Tissue or circulating C19MC miRNAs were not detectable in patients having 9 other types of vascular anomalies or unaffected children, identifying C19MC miRNAs as the first circulating biomarkers of IH. Levels of circulating C19MC miRNAs correlated with IH tumor size and propranolol treatment response, and IH tissue from children treated with propranolol or from children with partially involuted tumors contained lower levels of C19MC miRNAs than untreated, proliferative tumors, implicating C19MC miRNAs as potential drivers of IH pathogenesis. Detection of C19MC miRNAs in the circulation of infants with IH may provide a specific and noninvasive means of IH diagnosis and identification of candidates for propranolol therapy as well as a means to monitor treatment response.
Phenotypic and Cytogenetic Characterization of Mesenchymal Stromal Cells in De Novo Myelodysplastic Syndromes.Friday, September 23, 2016
Rathnayake AJ, Goonasekera HW, Dissanayake VH,
Analytical cellular pathology (Amsterdam). 08-09-2016
Bone marrow (BM) mesenchymal stem/stromal cells (MSCs) are vital in hematopoiesis. Whether BM-MSCs alter their characteristics in Myelodysplastic Syndromes (MDS) is still controversial. We characterized MSCs of de novo MDS patients in Sri Lanka who have not been reported previously in the literature. We also analyzed MSCs derived from different MDS subtypes. MSCs were culture-expanded, characterized by flow cytometry, and induced towards osteogenic and adipogenic differentiation. Growth properties were determined using growth curves and population doubling times. Karyotyping and FISH were performed on MSCs. Cell morphology, differentiation potential, and CD marker expression of MDS-MSCs of all subtypes were comparable to those of control-MSCs. No significant growth differences were observed between control MSCs and MDS-MSCs of all subtypes (p > 0.05). 31% of MDS-MSCs had chromosomal aberrations (der(3),del(6q),del(7p), loss of chromosomes) whose BM karyotypes were normal. Highest percentage of karyotypic abnormalities was observed in RCMD-MSCs. Patients with abnormal BM karyotypes had no aberrant MSC clones. Results show that in spite of presence of genetically abnormal clones in MDS-MSC populations, in vitro phenotypic and growth characteristics of MSCs in MDS remain unchanged. Further, the occurrence of genetic abnormalities in BM-MSCs in MDS could be considered as an autonomous event from that of their hematopoietic counterparts.
Efficient intravesical therapy of bladder cancer with cationic doxorubicin nanoassemblies.Friday, September 23, 2016
Jin X, Zhang P, Luo L, Cheng H, Li Y, Du T, Zou B, Gou M,
International journal of nanomedicine. 29-8-2016
Nanoparticles have promising applications in drug delivery for cancer therapy. Herein, we prepared cationic 1,2-dioleoyl-3-trimethylammonium propane/methoxypoly (ethyleneglycol) (DPP) nanoparticles to deliver doxorubicin (Dox) for intravesical therapy of bladder cancer. The DPP micelles have a mean dynamic diameter of 18.65 nm and a mean zeta potential of +19.6 mV. The DPP micelles could prolong the residence of Dox in the bladder, enhance the penetration of Dox into the bladder wall, and improve cellular uptake of Dox. The encapsulation by DPP micelles significantly improved the anticancer effect of Dox against orthotopic bladder cancer in vivo. This work described a Dox-loaded DPP nanoparticle with potential applications in intravesical therapy of bladder cancer.
Experimental bladder regeneration using a poly-l-lactide/silk fibroin scaffold seeded with nanoparticle-labeled allogenic bone marrow stromal cells.Friday, September 23, 2016
Yudintceva NM, Nashchekina YA, Blinova MI, Orlova NV, Muraviov AN, Vinogradova TI, Sheykhov MG, Shapkova EY, Emeljannikov DV, Yablonskii PK, Samusenko IA, Mikhrina AL, Pakhomov AV, Shevtsov MA,
International journal of nanomedicine. 08-9-2016
In the present study, a poly-l-lactide/silk fibroin (PL-SF) bilayer scaffold seeded with allogenic bone marrow stromal cells (BMSCs) was investigated as a potential approach for bladder tissue engineering in a model of partial bladder wall cystectomy in rabbits. The inner porous layer of the scaffold produced from silk fibroin was designed to promote cell proliferation and the outer layer produced from poly-l-lactic acid to serve as a waterproof barrier. To compare the feasibility and efficacy of BMSC application in the reconstruction of bladder defects, 12 adult male rabbits were divided into experimental and control groups (six animals each) that received a scaffold seeded with BMSCs or an acellular one, respectively. For BMSC tracking in the graft in in vivo studies using magnetic resonance imaging, cells were labeled with superparamagnetic iron oxide nanoparticles. In vitro studies demonstrated high intracellular incorporation of nanoparticles and the absence of a toxic influence on BMSC viability and proliferation. Following implantation of the graft with BMSCs into the bladder, we observed integration of the scaffold with surrounding bladder tissues (as detected by magnetic resonance imaging). During the follow-up period of 12 weeks, labeled BMSCs resided in the implanted scaffold. The functional activity of the reconstructed bladder was confirmed by electromyography. Subsequent histological assay demonstrated enhanced biointegrative properties of the PL-SF scaffold with cells in comparison to the control graft, as related to complete regeneration of the smooth muscle and urothelium tissues in the implant. Confocal microscopy studies confirmed the presence of the superparamagnetic iron oxide nanoparticle-labeled BMSCs in newly formed bladder layers, thus indicating the role of stem cells in bladder regeneration. The results of this study demonstrate that application of a PL-SF scaffold seeded with allogenic BMSCs can enhance biointegration of the graft in vivo and support bladder tissue regeneration and function.
Green synthesis of silver nanoparticles using Pimpinella anisum seeds: antimicrobial activity and cytotoxicity on human neonatal skin stromal cells and colon cancer cells.Friday, September 23, 2016
Alsalhi MS, Devanesan S, Alfuraydi AA, Vishnubalaji R, Munusamy MA, Murugan K, Nicoletti M, Benelli G,
International journal of nanomedicine. 06-9-2016
Overall, our results highlighted the capacity of P. anisum-synthesized AgNPs as novel and cheap bioreducing agents for eco-friendly nanosynthetical routes. The data confirm the multipurpose potential of plant-borne reducing and stabilizing agents in nanotechnology.
Carbon nanotube-based substrates promote cardiogenesis in brown adipose-derived stem cells via β1-integrin-dependent TGF-β1 signaling pathway.Friday, September 23, 2016
Sun H, Mou Y, Li Y, Li X, Chen Z, Duval K, Huang Z, Dai R, Tang L, Tian F,
International journal of nanomedicine. 06-9-2016
Stem cell-based therapy remains one of the promising approaches for cardiac repair and regeneration. However, its applications are restricted by the limited efficacy of cardiac differentiation. To address this issue, we examined whether carbon nanotubes (CNTs) would provide an instructive extracellular microenvironment to facilitate cardiogenesis in brown adipose-derived stem cells (BASCs) and to elucidate the underlying signaling pathways. In this study, we systematically investigated a series of cellular responses of BASCs due to the incorporation of CNTs into collagen (CNT-Col) substrates that promoted cell adhesion, spreading, and growth. Moreover, we found that CNT-Col substrates remarkably improved the efficiency of BASCs cardiogenesis by using fluorescence staining and quantitative real-time reverse transcription-polymerase chain reaction. Critically, CNTs in the substrates accelerated the maturation of BASCs-derived cardiomyocytes. Furthermore, the underlying mechanism for promotion of BASCs cardiac differentiation by CNTs was determined by immunostaining, quantitative real-time reverse transcription-polymerase chain reaction, and Western blotting assay. It is notable that β1-integrin-dependent TGF-β1 signaling pathway modulates the facilitative effect of CNTs in cardiac differentiation of BASCs. Therefore, it is an efficient approach to regulate cardiac differentiation of BASCs by the incorporation of CNTs into the native matrix. Importantly, our findings can not only facilitate the mechanistic understanding of molecular events initiating cardiac differentiation in stem cells, but also offer a potentially safer source for cardiac regenerative medicine.
Downregulation of DOCK1 sensitizes bladder cancer cells to cisplatin through preventing epithelial-mesenchymal transition.Friday, September 23, 2016
Chen DJ, Chen W, Jiang H, Yang H, Wang YC, Chen JH,
Drug design, development and therapy. 06-9-2016
During the past several decades, resistance to single or multiple anticancer agents has posed a great challenge in cancer therapy. Dedicator of cytokinesis 1 (DOCK1), the first identified member in DOCK family, plays diverse roles in cellular processes, including tumorigenesis. In this study, we explored the biological role of DOCK1 in the chemotherapeutic resistance in bladder cancer and its underlying mechanism. Our results showed that the bladder cancer cell lines UM-UC-3 and J82 with higher DOCK1 are more resistant to cisplatin, whereas B87 cells with the lowest expression of DOCK1 exhibited the highest sensitivity to cisplatin. Down-regulation of DOCK1 with small interfering RNA (siRNA) increased the cisplatin sensitivity in bladder cancer cells. Moreover, treatment with cisplatin induced epithelial-mesenchymal transition (EMT), while transfection with Twist siRNA restored the chemosensitivity to cisplatin. In addition, we found that downregulation of DOCK1 reversed EMT program in bladder cancer cells. However, cotransfection with DOCK1 siRNA could not further enhance the cisplatin sensitivity and cellular phenotypic changes in tumor cells. Taken together, these results demonstrate that downregulation of DOCK1 could increase the chemosensitivity in bladder cancer cells via preventing cisplatin-induced EMT, suggesting that DOCK1 may serve as a potential therapeutic target in bladder cancer.
Tankyrase inhibition promotes a stable human naïve pluripotent state with improved functionality.Friday, September 23, 2016
Zimmerlin L, Park TS, Huo JS, Verma K, Pather SR, Talbot CC, Agarwal J, Steppan D, Zhang YW, Considine M, Guo H, Zhong X, Gutierrez C, Cope L, Canto-Soler MV, Friedman AD, Baylin SB, Zambidis ET,
Development (Cambridge, England). 22-Sep-2016
The derivation and maintenance of hPSC in stable naïve pluripotent states has wide impact in human developmental biology. However, hPSC are unstable in classical naïve mouse ESC WNT and MEK/ERK signal inhibition (2i) culture. We show that a broad repertoire of conventional human embryonic stem cell (hESC) and transgene-independent hiPSC lines could be reverted to stable human preimplantation ICM-like naïve states with only WNT, MEK/ERK, and tankyrase inhibition (LIF-3i). LIF-3i-reverted hPSC retained normal karyotypes and attained defining mouse ESC-like functional features including high clonal self-renewal, independence from MEK-ERK signalling, dependence on JAK-STAT3 and BMP4 signaling, and naïve-specific transcriptional and epigenetic configurations. Tankyrase inhibition promoted a stable acquisition of a human preimplantation ICM-like ground state via modulation of WNT signalling, and was most efficacious in efficiently reprogrammed conventional hiPSC. Importantly, naïve reversion of a broad repertoire of conventional hiPSC reduced lineage-primed gene expression, and significantly improved their multi-lineage differentiation capacities. Stable naïve hPSC with reduced genetic variability and improved functional pluripotency will have great utility in regenerative medicine and human disease modeling.
Sox2 and Lef-1 interact with Pitx2 to regulate incisor development and stem cell renewal.Friday, September 23, 2016
Sun Z, Yu W, Navarro MS, Sweat M, Eliason S, Sharp T, Liu H, Seidel K, Zhang L, Moreno M, Lynch T, Holton NE, Rogers L, Neff T, Goodheart MJ, Michon F, Klein OD, Chai Y, Dupuy A, Engelhardt JF, Chen Z, Amendt BA,
Development (Cambridge, England). 22-Sep-2016
Sox2 marks dental epithelial stem cells (DESC) in both mammals and reptiles, and in this report we demonstrate several Sox2 transcriptional mechanisms that regulate dental stem cell fate and incisor growth. Conditional Sox2 deletion in the oral and dental epithelium results in severe craniofacial defects, including impaired dental stem cell proliferation, arrested incisor development and abnormal molar development. The murine incisor develops initially but is absorbed independent of apoptosis due to a lack of progenitor cell proliferation and differentiation. Tamoxifen induced inactivation of Sox2 demonstrates the requirement of Sox2 for maintenance of the DESCs in adult mice. Conditional overexpression of Lef-1 in mice increases DESC proliferation and creates a new labial cervical loop stem cell compartment, which produces rapidly growing long tusk-like incisors, and Lef-1 epithelial overexpression partially rescues the tooth arrest in Sox2 conditional knockout mice. Mechanistically, Pitx2 and Sox2 interact physically and regulate Lef-1, Pitx2 and Sox2 expression during development. Thus, we have uncovered a Pitx2:Sox2:Lef-1 transcriptional mechanism that regulates DESC homeostasis and dental development.
Restoration of Hydrogen Sulfide Production in Diabetic Mice Improves Reparative Function of Bone Marrow Cells.Friday, September 23, 2016
Cheng Z, Garikipati V, Nickoloff E, Wang C, Polhemus DJ, Zhou J, Benedict C, Khan M, Verma SK, Rabinowitz JE, Lefer D, Kishore R,
Circulation. 22-Sep-2016
-Decreased CSE-mediated H2S bioavailability is an underlying source of BMC dysfunction in diabetes. Our data indicate that H2S and overexpression of CSE in diabetic BMCs may rescue their dysfunction and open novel avenues for cell-based therapeutics of CLI in diabetic patients.
Activation of Transient Receptor Potential Vanilloid 4 Promotes the Proliferation of Stem Cells in the Adult Hippocampal Dentate Gyrus.Friday, September 23, 2016
Tian Y, Qi M, Hong Z, Li Y, Yuan Y, Du Y, Chen L, Chen L,
Molecular neurobiology. 22-Sep-2016
Neurogenesis plays an important role in adult hippocampal function, and this process can be modulated by intracellular calcium. The activation of transient receptor potential vanilloid 4 (TRPV4) induces an increase in intracellular calcium concentration, but whether neurogenesis can be modulated by TRPV4 activation remains unclear. Here, we report that intracerebroventricular injection of the TRPV4 agonist GSK1016790A for 5 days enhanced the proliferation of stem cells in the hippocampal dentate gyrus (DG) of adult mice without affecting neurite growth, differentiation, or survival of newborn cells. GSK1016790A induced increases in the hippocampal protein levels of cyclin-dependent kinase (CDK) 6, CDK2, cyclin E1, and cyclin A2 but did not affect CDK4 and cyclin D1 expression. The phosphorylation of retinoblastoma protein (Rb) in hippocampi was enhanced in GSK1016790A-injected mice compared with control mice. Moreover, hippocampal protein levels of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation were enhanced by GSK1016790A. Finally, GSK1016790A-enhanced proliferation was markedly blocked by a MAPK/ERK kinase or p38 MAPK antagonist (U0126 or SB203580, respectively). The increased protein levels of CDK2 and CDK6, as well as those of cyclin E1 and cyclin A2, in GSK1016790A-injected mice were substantially reduced by co-injection of U0126 or SB203580. We conclude that TRPV4 activation results in the proliferation of stem cells in the adult hippocampal DG, which is likely mediated through ERK1/2 and p38 MAPK signaling to increase the expression of CDKs (CDK6 and CDK2) and cyclins (cyclin E1 and A2), phosphorylate Rb consequently, and accelerate the cell cycle ultimately.
MicroRNA-Mediated Reprogramming of Somatic Cells into Neural Stem Cells or Neurons.Friday, September 23, 2016
Yang H, Zhang L, An J, Zhang Q, Liu C, He B, Hao DJ,
Molecular neurobiology. 22-Sep-2016
Cellular reprogramming is a promising strategy to generate neural stem cells (NSCs) or desired subtype-specific neurons for cell-based therapeutic intervention. By far, the intricate cell event like reprogramming of non-neural cells to desired cell types can be achieved by forced expression of lineage-related transcription factors (TFs), nuclear transfer, a defined set of factors, and via non-coding microRNAs (miRNAs), as well as other precisely defined conditions. In addition, scientists have been trying to develop better approaches for reprogramming, either by using distinct combinations of a set of small molecules and certain TFs or delivery of appropriate small molecules and miRNAs. The miRNA-mediated approach is fascinating because of its potential to rapidly generate a variety of therapeutically desired cell types from other cell lineages. Recent studies have made great progress in miRNA-mediated neural reprogramming of somatic cells to various specific neuronal subtypes with more efficiency even though the exact mechanisms remain to be further explored. Based on key roles of miRNAs in neural reprogramming across differentiated cell lineages, it is of vital interest to summarize the recent knowledge regarding the instructive role of miRNAs in direct conversion of somatic cells into neural lineages. This precise review mainly focuses on recent discoveries of miRNAs functions in initiating cell reprogramming and fate specification of the neuronal subtype. Moreover, we discuss most recent findings about some miRNAs' activity in regulating various developmental stages of neurons, which is helpful for understanding the event network between miRNAs and their targets.
Sepsis and septic shock-is a microcirculation a main player?Friday, September 23, 2016
Lipinska-Gediga M,
Anaesthesiology intensive therapy. 23-Sep-2016
Shock, defined at a cellular level, is a condition in which oxygen delivery to the cells is not sufficient to sustain cellular activity and support organ function. The central role of microcirculation in providing oxygen to the cells makes it of prime importance in determining organ function. In sepsis and septic shock, macrocirculatory alterations and microcirculatory dysfunction participate concurrently in the pathophysiology of organ failure. Haemodynamic coherence in shock is a condition in which normalization of systemic haemodynamic variables results in simultaneous amelioration in the perfusion of the microcirculation and restoration of tissue oxygenation as a final result. Septic shock is most frequently characterized by a lack of microcirculatory recruitment despite of macrocirculatory successful resuscitation. The lack of haemodynamic coherence between macrocirculation and microcirculation in septic patients results in treatment failure and increased mortality. The monitoring of microcirculation and the effects of its changes are an important area of future clinical research and treatment modification.
Expression and localization of forkhead box protein FOXJ1 in S100β-positive multiciliated cells of the rat pituitary.Friday, September 23, 2016
Nakakura T, Suzuki T, Horiguchi K, Fujiwara K, Tsukada T, Asano-Hoshino A, Tanaka H, Arisawa K, Nishijima Y, Nekooki-Machida Y, Kiuchi Y, Hagiwara H,
Medical molecular morphology. 22-Sep-2016
S100β-positive cells exist in the marginal cell layer (MCL) of the adenohypophysis and follicle structure in the parenchyma of anterior lobe (ALFS) in pituitary. They have multiple functions as phagocytes or cells that regulate hormone secretion. Majority of S100β-positive cells in the adenohypophysis express sex determining region Y-box 2 protein (SOX2), a stem cell marker; therefore, S100β/SOX2 double positive cells are also considered as one type of stem/progenitor cells. MCL and ALFS are consisting of morphologically two types of cells, i.e., multiciliated cells and non-ciliated cells. However, the relationship between the S100β-positive cells and multiciliated cells in the pituitary is largely unknown. In the present study, we first immunohistochemically verified the feature of multiciliated cells in MCL and ALFS. We then examined the expression patterns of FOXJ1, an essential expression factor for multiciliated cell-differentiation, and SOX2 in the S100β-positive multiciliated cells by in situ hybridization and immunohistochemistry. We identified anew the S100β/SOX2/FOXJ1 triple positive multiciliated cells, and revealed that they were dispersed throughout the MCL and ALFS. These results indicate that the MCL and ALFS are consisting of morphologically and functionally distinct two types of cells, i.e., S100β/SOX2 double positive non-ciliated cells and S100β/SOX2/FOXJ1 triple positive multiciliated cells.
Heterogeneity of CD34 and CD38 expression in acute B lymphoblastic leukemia cells is reversible and not hierarchically organized.Friday, September 23, 2016
Jiang Z, Deng M, Wei X, Ye W, Xiao Y, Lin S, Wang S, Li B, Liu X, Zhang G, Lai P, Weng J, Wu D, Chen H, Wei W, Ma Y, Li Y, Liu P, Du X, Pei D, Yao Y, Xu B, Li P,
Journal of hematology & oncology. 22-9-2016
The existence and identification of leukemia-initiating cells in adult acute B lymphoblastic leukemia (B-ALL) remain controversial. We examined whether adult B-ALL is hierarchically organized into phenotypically distinct subpopulations of leukemogenic and non-leukemogenic cells or whether most B-ALL cells retain leukemogenic capacity, irrespective of their immunophenotype profiles. Our results suggest that adult B-ALL follows the stochastic stem cell model and that the expression of CD34 and CD38 in B-ALL is reversibly and not hierarchically organized.
Activated monocytes resist elimination by retinal pigment epithelium and downregulate their OTX2 expression via TNF-α.Friday, September 23, 2016
Mathis T, Housset M, Eandi C, Beguier F, Touhami S, Reichman S, Augustin S, Gondouin P, Sahel JA, Kodjikian L, Goureau O, Guillonneau X, Sennlaub F,
Aging cell. 22-Sep-2016
Orthodenticle homeobox 2 (OTX2) controls essential, homeostatic retinal pigment epithelial (RPE) genes in the adult. Using cocultures of human CD14(+) blood monocytes (Mos) and primary porcine RPE cells and a fully humanized system using human-induced pluripotent stem cell-derived RPE cells, we show that activated Mos markedly inhibit RPEOTX2 expression and resist elimination in contact with the immunosuppressive RPE. Mechanistically, we demonstrate that TNF-α, secreted from activated Mos, mediates the downregulation of OTX2 and essential RPE genes of the visual cycle among others. Our data show how subretinal, chronic inflammation and in particular TNF-α can affect RPE function, which might contribute to the visual dysfunctions in diseases such as age-related macular degeneration (AMD) where subretinal macrophages are observed. Our findings provide important mechanistic insights into the regulation of OTX2 under inflammatory conditions. Therapeutic restoration of OTX2 expression might help revive RPE and visual function in retinal diseases such as AMD.
Aging and anti-aging.Friday, September 23, 2016
Lara J, Sherratt MJ, Rees M,
Maturitas. 24-Aug-2016
The effect of Me2SO overexposure during cryopreservation on HOS TE85 and hMSC viability, growth and quality.Friday, September 23, 2016
Morris TJ, Picken A, Sharp DM, Slater NK, Hewitt CJ, Coopman K,
Cryobiology. 19-Sep-2016
With the cell therapy industry continuing to grow, the ability to preserve clinical grade cells, including mesenchymal stem cells (MSCs), whilst retaining cell viability and function remains critical for the generation of off-the-shelf therapies. Cryopreservation of MSCs, using slow freezing, is an established process at lab scale. However, the cytotoxicity of cryoprotectants, like Me2SO, raises questions about the impact of prolonged cell exposure to cryoprotectant at temperatures >0 °C during processing of large cell batches for allogenic therapies prior to rapid cooling in a controlled rate freezer or in the clinic prior to administration. Here we show that exposure of human bone marrow derived MSCs to Me2SO for ≥1 h before freezing, or after thawing, degrades membrane integrity, short-term cell attachment efficiency and alters cell immunophenotype. After 2 h's exposure to Me2SO at 37 °C post-thaw, membrane integrity dropped to ∼70% and only ∼50% of cells retained the ability to adhere to tissue culture plastic. Furthermore, only 70% of the recovered MSCs retained an immunophenotype consistent with the ISCT minimal criteria after exposure. We also saw a similar loss of membrane integrity and attachment efficiency after exposing osteoblast (HOS TE85) cells to Me2SO before, and after, cryopreservation. Overall, these results show that freezing medium exposure is a critical determinant of product quality as process scale increases. Defining and reporting cell sensitivity to freezing medium exposure, both before and after cryopreservation, enables a fair judgement of how scalable a particular cryopreservation process can be, and consequently whether the therapy has commercial feasibility.
Isolation and Culture of Muscle Stem Cells.Friday, September 23, 2016
Mozzetta C,
Methods in molecular biology (Clifton, N.J.). 2016
Polycomb group (PcG) proteins are key epigenetic factors responsible for the proper spatiotemporal repression of defined transcriptional programs along the process of cell differentiation, including myogenesis. The discovery of the pivotal role played by PcG factors during myogenic differentiation relied on the possibility to culture myogenic cells in vitro. We describe here the methods currently used to isolate muscle stem cells (MuSCs) both from single myofibers and from bulk muscles by fluorescence-activated cell sorting (FACS), highlighting experimental details and critical steps. Through these techniques MuSCs can be efficiently isolated and cultured in vitro to recapitulate the different phases of myogenesis: activation, expansion, differentiation, and self-renewal.
Reprogramming of Somatic Cells Towards Pluripotency by Cell Fusion.Friday, September 23, 2016
Malinowski AR, Fisher AG,
Methods in molecular biology (Clifton, N.J.). 2016
Pluripotent reprogramming can be dominantly induced in a somatic nucleus upon fusion with a pluripotent cell such as embryonic stem (ES) cell. Cell fusion between ES cells and somatic cells results in the formation of heterokaryons, in which the somatic nuclei begin to acquire features of the pluripotent partner. The generation of interspecies heterokaryons between mouse ES- and human somatic cells allows an experimenter to distinguish the nuclear events occurring specifically within the reprogrammed nucleus. Therefore, cell fusion provides a simple and rapid approach to look at the early nuclear events underlying pluripotent reprogramming. Here, we describe a polyethylene glycol (PEG)-mediated cell fusion protocol to generate interspecies heterokaryons and intraspecies hybrids between ES cells and B lymphocytes or fibroblasts.
Analysis of Endogenous Protein Interactions of Polycomb Group of Proteins in Mouse Embryonic Stem Cells.Friday, September 23, 2016
Morey L, Di Croce L,
Methods in molecular biology (Clifton, N.J.). 2016
PRC1 complexes contain four core subunits: Pcgf, Phc, Ring1, and Cbx proteins. Interestingly, mammalian genomes have several paralogues for each subunit, which are differentially expressed depending on the cell type, differentiation program, and cellular stimuli. Therefore, identification and characterization of the specific architecture of different PRC1 complexes during cellular differentiation are essential to better understand the function and recruitment mechanism of PRC1 complexes. In this chapter we describe several methods to study Polycomb architecture, and identification of novel interactors in both pluripotent and differentiating mouse embryonic stem cells.
The Dynamics of Polycomb Complexes.Friday, September 23, 2016
Palacios D,
Methods in molecular biology (Clifton, N.J.). 2016
Polycomb complexes are essential regulators of embryonic and adult stem cells, highly conserved from flies to mammals. Traditionally, their study was based on biochemical and genetic approaches. More recently, the development of novel technologies and the improvement and standardization of existing ones has allowed to address previously unexplored aspects of Polycomb biology, such as dynamics and regulation. In this chapter, relevant researchers in the field discuss novel technologies aimed at dissecting the dynamics of Polycomb complexes in normal and pathological conditions.
Source: NCBI - Disclaimer and Copyright notice
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