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

Blockade of Learning and Memory Genes may Occur Early in Alzheimer's Disease

Published: Thursday, March 01, 2012
Last Updated: Thursday, March 01, 2012
Bookmark and Share
A repression of gene activity in the brain appears to be an early event affecting people with Alzheimer's disease. In mouse models of Alzheimer's disease, this epigenetic blockade and its effects on memory were treatable.

"These findings provide a glimpse of the brain shutting down the ability to form new memories gene by gene in Alzheimer's disease, and offer hope that we may be able to counteract this process," said Roderick Corriveau, Ph.D., a program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS), which helped fund the research.

The study was led by Li-Huei Tsai, Ph.D., who is director of The Picower Institute for Learning and Memory at the Massachusetts Institute of Technology and an investigator at the Howard Hughes Medical Institute. It was published online February 29 in Nature.

Dr. Tsai and her team found that a protein called histone deacetylase 2 (HDAC2) accumulates in the brain early in the course of Alzheimer's disease in mouse models and in people with the disease. HDAC2 is known to tighten up spools of DNA, effectively locking down the genes within and reducing their activity, or expression.

In the mice, the increase in HDAC2 appears to produce a blockade of genes involved in learning and memory. Preventing the build-up of HDAC2 protected the mice from memory loss.

Dr. Tsai and her team examined two mouse models of Alzheimer's around the time that the mice begin to show signs of brain cell degeneration. They found that the mice had higher levels of HDAC2, but not other related HDAC proteins, specifically in the parts of the brain involved in learning and memory. This increase in HDAC2 was associated with a decrease in the expression of neuronal genes that HDAC2 is known to regulate.

Use of a gene therapy approach to reduce the levels of HDAC2 prevented the blockade of gene expression. The treatment also prevented learning and memory impairments in the mice. It did not prevent neuronal death, but it did enhance neuroplasticity — the ability of neurons to form new connections.

Dr. Tsai and her team also examined HDAC2 levels in autopsied brain tissue from 19 people with Alzheimer’s at different stages of the disease, and from seven unaffected individuals. Even in its earliest stages, the disease was associated with higher HDAC2 levels in the learning and memory regions of the brain.

"We think that the blockade of gene expression plays a very important role in the cognitive decline associated with Alzheimer's disease," said Dr. Tsai. "The good news is that the blockade is potentially reversible."

Alzheimer's disease is the most common cause of dementia in older adults, and affects as many as 5.1 million Americans. In the most common type of Alzheimer's disease, symptoms usually appear after age 65. A hallmark of the disease is the accumulation of a toxic protein fragment called beta-amyloid in brain cells, which is widely believed to be the initial trigger for neurodegeneration.

Dr. Tsai theorizes that HDAC2 is brought into play by beta-amyloid. Indeed, she and her team found that exposing mouse neurons to beta-amyloid caused them to produce more HDAC2.

"We think beta-amyloid triggers a cascade of damaging reactions. Once of these is to activate HDAC2, which in turn blocks the expression of genes needed for brain plasticity. Once this blockade is in place, it may have a more systemic, chronic effect on the brain," she said.

Vaccines and other therapies aimed at reducing beta-amyloid are in clinical trials. Efforts to reduce HDAC2 may provide a complementary approach to treating Alzheimer's, Dr. Tsai said. She has previously reported that HDAC inhibitor compounds can protect against signs of Alzheimer's disease in mice. A problem with such compounds is that they inhibit not only HDAC2 but related HDAC proteins, leading to broad and potentially toxic effects. The new study supports the possibility of developing drugs more specifically targeted to HDAC2 and the pathology of Alzheimer’s disease, Dr. Tsai said. Her team is working to identify HDAC2-specific inhibitors that could be developed into drugs and moved into trials.

Dr. Tsai's study was supported by NINDS and the National Institute on Aging through the NIH Common Fund Epigenomics Program. Additional support was provided through the NIH Blueprint for Neuroscience Research and its Neuroplasticity initiative.


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 4,000+ scientific posters on ePosters
  • More than 5,300+ 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

Protein-Folding Gene Helps Heal Wounds
Researchers identified a protein that dramatically accelerates wound healing in animal models.
Wednesday, November 23, 2016
NIH Researchers Unveil New Wound-Healing Role for Protein-Folding Gene in Mice
The study found that topical treatment of an Hsp60-containing gel dramatically accelerates wound closure in a diabetic mouse model.
Friday, October 28, 2016
Gene Editing Corrects Sickle Cell Mutation
Researchers demonstrate a potential pathway to developing gene-editing treatments for sickle cell disease.
Wednesday, October 26, 2016
NIH Scientists Uncover Genetic Explanation for Frustrating Syndrome
Researchers at NIH have suggested that the multiple alpha tryptase gene copies might underlie health issues that affect a substantial number of people.
Tuesday, October 18, 2016
NIH Commits $6.7 M to Advance DNA, RNA Sequencing Technology
"Can you believe they make DNA sequencers the size of staplers?" asked Meni Wanunu, Ph.D. "Ideas that were crazy twenty years ago are now happening!"
Friday, October 07, 2016
“Sixth Sense” More Than a Feeling
NIH study of rare genetic disorder reveals importance of touch and body awareness.
Monday, September 26, 2016
The Genetics of Blood Pressure
Researchers have identifed areas of the genome associated with blood-pressure including 17 previously unknown loci.
Wednesday, September 21, 2016
Catalogue of Human Genetic Diversity Expands
The largest data set of human exomes to date has been assembled to better study seqence variants and their consequences.
Wednesday, September 07, 2016
$12.4M Awarded to Neural Regeneration Projects
The National Institutes of Health will fund six projects to identify biological factors that influence neural regeneration.
Friday, September 02, 2016
New Inflammatory Disease Discovered
NIH researchers have discovered a rare and potentially deadly disease - otulipenia - the mostly affects children.
Tuesday, August 23, 2016
Public Support for National Study
Survey shows the majority of respondents support or show willingness for national precision medicine study.
Thursday, August 18, 2016
Schizophrenia, Autism Share Genetic Causes
Monkey brain developmental atlas pinpoints when, where genes activate.
Tuesday, August 16, 2016
How Breast Cancers Resist Chemotherapy
Researchers discovered an unexpected way that breast cancers cells with mutant BRCA1 or BRCA2 genes acquire drug resistance and evade chemotherapies.
Wednesday, August 10, 2016
Mutations Linked to Immunotherapy Resistance
Researchers uncover mutations in tumors of three patients with advanced melanoma that allowed the tumors to become resistant to the immune checkpoint inhibitor pembrolizumab (Keytruda®).
Tuesday, August 09, 2016
Genetic Cause of Rare Pediatric Neuropathy Identified
NIH mouse study identifies the mechanism responsible for a rare form of pediatric neuropathy.
Thursday, August 04, 2016
Scientific News
Big Genetics in BC: The American Society for Human Genetics 2016 Meeting
Themes at this year's meeting ranged from the verification, validation, and sharing of data, to the translation of laboratory findings into actionable clinical results.
Cancer Genetics: Key to Diagnosis, Therapy
When applied judiciously, cancer genetics directs caregivers to the right drug at the right time, while sparing patients of unnecessary or harmful treatments.
Tissue Damage Is Key for Cell Reprogramming
Researchers have shown tissue damage is important for cells to return to an embryonic state for cell reprogramming.
Improving Drug Production with Computer Model
A model has been developed that can be used to improve and accelerate the production of biotherapeutics, cancer drugs, and vaccines.
New Form of Autism Found
An international team of researchers have identified a new form of syndromic autism.
Accelerating the Detection of Foodborne Bacterial Outbreaks
The speed of diagnosis of foodborne bacterial outbreaks could be improved by a new technique developed by researchers at the Georgia Institute of Technology.
Scientists Identify Unique Genomic Features in Testicular Cancer
The findings may shed light on factors in other cancers that influence their sensitivity to chemotherapy.
Top 10 Life Science Innovations of 2016
2016 has seen the release of some truly innovative products. To help you digest these developments, The Scientist have listed their top picks for the year.
Secret Phenotypes: Disease Devils in Invisible Details
Algorithmic deep phenotyping exposes masses of hidden traits and possible subtle genetic connections relevant to unseen influences on disease.
Hunting the Missing Link Between Genetics and the Environment
The International Phenome Centre Network (IPCN) works to transform healthcare through phenomics - the dynamic interactions between our genes and our environment.
Skyscraper Banner

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
4,000+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
5,300+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!