Corporate Banner
Satellite Banner
Proteomics
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Proteins Causing Daytime Sleepiness Also Tied to Bone Formation

Published: Saturday, June 14, 2014
Last Updated: Saturday, June 14, 2014
Bookmark and Share
Orexin proteins provide target for osteoporosis, UT Southwestern researchers find.

Orexin proteins, which are blamed for spontaneous daytime sleepiness, also play a crucial role in bone formation, according to findings by UT Southwestern Medical Center researchers. The findings could potentially give rise to new treatments for osteoporosis, the researchers say.

Orexins are a type of protein used by nerve cells to communicate with each other. Since their discovery at UT Southwestern more than 15 years ago, they have been found to regulate a number of behaviors, including arousal, appetite, reward, energy expenditure, and wakefulness. Orexin deficiency, for example, causes narcolepsy - spontaneous daytime sleepiness. Thus, orexin antagonists are promising treatments for insomnia, some of which have been tested in Phase III clinical trials.

UT Southwestern researchers, working with colleagues in Japan, now have found that mice lacking orexins also have very thin and fragile bones that break easily because they have fewer cells called osteoblasts, which are responsible for building bones.

“Osteoporosis is highly prevalent, especially among post-menopausal women. We are hoping that we might be able to take advantage of the already available orexin-targeting small molecules to potentially treat osteoporosis,” said Dr. Yihong Wan, Assistant Professor of Pharmacology, the Virginia Murchison Linthicum Scholar in Medical Research, and senior author for the study, published in the journal Cell Metabolism.

Osteoporosis, the most common type of bone disease in which bones become fragile and susceptible to fracture, affects more than 10 million Americans. The disease, which disproportionately affects seniors and women, leads to more than 1.5 million fractures and some 40,000 deaths annually. In addition, the negative effects impact productivity, mental health, and quality of life. One in five people with hip fractures, for example, end up in nursing homes.

Orexins seem to play a dual role in the process: they both promote and block bone formation. On the bones themselves, orexins interact with another protein, orexin receptor 1 (OX1R), which decreases the levels of the hunger hormone ghrelin. This slows down the production of new osteoblasts and, therefore, blocks bone formation locally.

At the same time, orexins interact with orexin receptor 2 (OX2R) in the brain. In this case, the interaction reduces the circulating levels of leptin, a hormone known to decrease bone mass, and thereby promotes bone formation. Therefore, osteoporosis prevention and treatment may be achieved by either inhibiting OX1R or activating OX2R.

“We were very intrigued by this yin-yang-style dual regulation,” said Dr. Wan, a member of the Cecil H. and Ida Green Center for Reproductive Biology Sciences and UT Southwestern’s Harold C. Simmons Comprehensive Cancer Center. “It is remarkable that orexins manage to regulate bone formation by using two different receptors located in two different tissues.”

The central nervous system regulation through OX2R, and therefore promotion of bone formation, was actually dominant over regulation through OX1R. So when the group examined mice lacking both OX1R and OX2R, they had very fragile bones with decreased bone formation. Similarly, when they assessed mice that expressed high levels of orexins, those mice had increased numbers of osteoblasts and enhanced bone formation.

The research was done in collaboration with Dr. Masashi Yanagisawa, Adjunct Professor of Molecular Genetics at UT Southwestern, a Howard Hughes Medical Institute investigator, and now with the International Institute for Integrative Sleep Medicine at the University of Tsukuba, in Japan. Dr. Yanagisawa’s laboratory discovered orexins in 1998.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,200+ scientific posters on ePosters
  • More than 4,800+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

New Autism Blood Biomarker Identified
Researchers at UT Southwestern Medical Center have identified a blood biomarker that may aid in earlier diagnosis of children with autism spectrum disorder, or ASD.
Friday, May 06, 2016
Researchers Find New Cytoplasmic Role
Researchers at UT Southwestern Medical Center have found new cytoplasmic role for proteins linked to neurological diseases, cancers.
Friday, March 18, 2016
HIV Protein Manipulates Hundreds of Human Genes
Findings search for new or improved treatments for patients with AIDS.
Thursday, January 28, 2016
Researchers Find a Small Protein that Plays a Big Role in Heart Muscle Contraction
New protein, DWORF, stimulates a calcium-ion pump that controls muscle contraction.
Friday, January 15, 2016
UTSW-led Study Establishes Biomarkers to Help Diagnose, Treat Psychosis
In this study, the Bipolar-Schizophrenia Network on Intermediate Phenotypes identified three neurobiologically distinct biotypes.
Saturday, December 12, 2015
Physiologists Uncover a New Code at the Heart of Biology
New “code” - the speed limit of assembly - dictate the ultimate function of a given protein.
Thursday, September 24, 2015
Cell that Replenishes Heart Muscle Found by UT Southwestern Researchers
Researchers devise a new cell-tracing technique to detect cells that do replenish themselves.
Tuesday, June 23, 2015
Researchers Find Molecular Mechanisms within Fetal Lungs that Initiate Labor
Biochemists found that steroid receptor coactivators 1 and 2 (SRC-1 and SRC-2) proteins control genes.
Tuesday, June 23, 2015
MAGE Genes Provide Insight into Optimizing Chemotherapy
UT Southwestern Medical Center scientists have identified a new biomarker that could help identify patients who are more likely to respond to certain chemotherapies.
Tuesday, February 17, 2015
Researchers Find New Mechanism That Controls Immune Responses
The findings appear online in the journal Science.
Friday, February 13, 2015
Protein Variant may Boost Cardiovascular Risk by Hindering Blood Vessel Repair
Researchers have found that apoE3 helps repair the lining of blood vessels.
Friday, September 19, 2014
UTSW Cancer Researchers Identify Irreversible Inhibitor for KRAS Gene Mutation
Irreversible inhibitor for KRAS gene mutation involved in lung, colon, and pancreatic cancers.
Tuesday, July 29, 2014
UT Southwestern Researcher Selected for ASBMB Merck Award
Award recognizes Dr. Zhijian Chen’s outstanding contributions to research in biochemistry and molecular biology.
Friday, July 18, 2014
Cellular Force That Drives Allergy and Asthma Can be Blocked by Interferon
Type I interferons block the development of allergy- and asthma-driving Th2 cells.
Friday, June 20, 2014
New Mechanism Explains How Cancer Cells Spread
A protein critical to the spread of deadly cancer cells has been identified and how it works determined.
Wednesday, May 28, 2014
Scientific News
Liquid Biopsies: Miracle Diagnostic or Next New Fad?
Thanks to the development of highly specific gene-amplification and sequencing technologies liquid biopsies access more biomarkers relevant to more cancers than ever before.
Cell Cargo Ships in Near Future?
Virus-inspired container design may lead to cell cargo ships following construction of ten large, two-component, icosahedral protein complexes.
Protein Reinforces Growth of Damaged Muscles
Biologists have found a protein involved in stem cells that bolsters damaged muscle tissue growth - potential for muscle degeneration treatments.
Structure of Cold Virus Solved
Researchers have identified the structure of an elusive cold virus linked to child asthma and respiratory infections, providing the foundation for treating the virus.
New Protein Model Could Accelerate Drug Development
Stony Brook-led international research team creates ultra-fast approach to model protein interactions.
Researchers Can Control Genes Involved in Cancer
A new way to control the activity of a protein, that is often upregulated in cancer, has been discovered by Moffitt researchers through monoubiquitination mechanism.
Mitochondrial Role in Metastatic Cancer
Researchers have manipulated proteins, sourced from tumour cells, that are essential for maintaining tumour cells and in doing so, have significantly reduced the ability of cancer cells.
Liquid Biopsy Predicts Colon Cancer Recurrence
Scientists have used a genetic test that spots bits of cancer-related DNA circulating in the blood to accurately predict the likelihood of the disease’s return in some — but not all — of a small group of patients with early-stage colon cancer.
Scientists Culture Elusive Yellowstone Microbe
ORNL scientists have successfully isolated and cultured a Yellowstone sourced acidic hot-spring based microbe.
Seeing RNA at the Nanoscale
MIT researchers have developed a new way to image proteins and RNA inside neurons of brain tissue.
Scroll Up
Scroll Down
SELECTBIO

SELECTBIO Market Reports
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,200+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,800+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!