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

Epigenetic Clock Marks Age of Human Tissues and Cells

Published: Tuesday, November 05, 2013
Last Updated: Tuesday, November 05, 2013
Bookmark and Share
The age of many human tissues and cells is reflected in chemical changes to DNA. The finding provides insights for cancer, aging, and stem cell research.

We may gauge how we’re aging based on visible changes, such as wrinkles. For years, scientists have been trying to gauge aging based on changes inside our cells.

Many alterations occur to our DNA as we age. Some of these changes are epigenetic—they modify DNA without altering the genetic sequence itself. These changes affect how cells in different parts of the body use the same genetic code. By controlling when specific genes are turned on and off, or “expressed,” they tell cells what to do, where to do it, and when to do it.

One such type of modification occurs when chemical tags known as methyl groups attach to DNA in specific places. This process, known as methylation, affects interactions between DNA and protein-making machinery. Changes in DNA methylation—both increases and decreases—occur with aging.

Dr. Steve Horvath from the University of California, Los Angeles, examined the relationship between DNA methylation and aging. He took advantage of publicly available methylation datasets, including ones from The Cancer Genome Atlas, a joint effort of NIH’s National Cancer Institute (NCI) and National Human Genome Research Institute (NHGRI). The datasets were developed by hundreds of researchers and comprised almost 8,000 samples of 51 healthy tissues and cell types. Samples came from people ranging in age from newborns to 101 years. They included tissues from throughout the body, including the brain, breast, skin, colon, kidney, liver, lung, and heart.

Horvath first developed an age predictor using 39 datasets. The tool was based on 353 specific DNA sites where methyl groups increased or decreased with age. He then tested the predictor in 32 additional datasets. Results appeared in the October 21, 2013, issue of Genome Biology.

Horvath found that the computed biological age based on DNA methylation closely predicted the chronological age of numerous tissues and cells to within just a few years. There were some tissues, however, where the biological age did not match the chronological age. These included skeletal muscle, heart tissue, and breast tissue. The clock also worked well in chimpanzees.

In both embryonic and induced pluripotent stem cells—genetically altered adult cells with characteristics of embryonic stem cells—the DNA methylation age proved to be near zero.

Horvath also analyzed nearly 6,000 samples from 20 different cancers and found that cancer greatly affected DNA methylation age. However, in most cancers the age acceleration didn’t reflect the tumor grade and stage.

The rate of ticking of the biological clock, as measured by the rates of change in DNA methylation, wasn’t constant. It was faster from birth to adulthood, and then slowed to a constant rate around the age of 20.

Horvath didn’t find evidence of a relationship with DNA methylation age in B cells (a type of white blood cell) from people with a premature aging disease (progeria).

“Pinpointing a set of biomarkers that keeps time throughout the body has been a 4-year challenge,” Horvath says. “My goal in inventing this age-predictive tool is to help scientists improve their understanding of what speeds up and slows down the human aging process.”

UCLA has filed a provisional patent on the age-predictive tool, which is freely available to scientists online. Horvath plans to examine whether DNA methylation is only a marker of aging or itself affects aging.

Further Information
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 2,600+ scientific posters on ePosters
  • More than 3,800+ 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 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

NIH Funding Targets Gaps in Biomedical Research
New awards support emerging issues in cutting-edge biomedical research fields.
Tuesday, October 06, 2015
NIH Framework Points The Way Forward For Developing The President’s Precision Medicine Initiative
The NIH Advisory Committee to the Director has presented to NIH Director Francis S. Collins, M.D., Ph.D., a detailed design framework for building a national research participant group, called a cohort, of 1 million or more Americans to expand our knowledge and practice of precision medicine.
Monday, September 21, 2015
Beth Israel Cardiology Team Awarded $3 Million by NIH
Work will help predict outcomes in patients with heart disease.
Friday, September 18, 2015
Novel Mechanism to Explain Autoimmune Uveitis Proposed
A new study on mice suggests that bacteria in the gut may provide a kind of training ground for immune cells to attack the eye.
Wednesday, August 19, 2015
Nuclear Process in the Brain That May Affect Disease Uncovered
Scientists have shown that the passage of molecules through the nucleus of a star-shaped brain cell, called an astrocyte, may play a critical role in health and disease.
Tuesday, August 18, 2015
Scientists Uncover Nuclear Process in the Brain that May Affect Disease
NIH-funded study highlights the possible role of glial brain cells in neurological disorders.
Tuesday, August 18, 2015
PINK1 Protein Crucial for Removing Broken-Down Energy Reactors
NIH study suggests potential new pathway to target for treating ALS and other diseases.
Thursday, August 13, 2015
Tell-tale Biomarker Detects Early Breast Cancer in NIH-funded Study
The study published online in the issue of Nature Communications.
Thursday, August 13, 2015
Researchers Identify Protein in Mice that Helps Prepare for Healthy Egg-sperm Union
Protein RGS2 plays a critical role in preserving the fertilizability of the ovulated egg.
Wednesday, August 05, 2015
Protein Related to Long Term Traumatic Brain Injury Complications Discovered
NIH-study shows protein found at higher levels in military members who have suffered multiple TBIs.
Tuesday, August 04, 2015
Crystal Clear Images Uncover Secrets of Hormone Receptors
NIH researchers gain better understanding of how neuropeptide hormones trigger chemical reactions in cells.
Monday, August 03, 2015
Vital Protein in Healthy Fertilization Process Identified
Researchers at the National Institutes of Health have discovered a protein that plays a vital role in healthy egg-sperm union in mice.
Monday, July 27, 2015
NIH Joins Public-Private Partnership to Fund Research on Autism Biomarkers
Biomarkers Consortium project to improve tools for measuring and treating social impairment in children with autism.
Tuesday, July 21, 2015
Mystery of the Tubulin Code Unravelled
NIH study provides a glimpse into the code that controls variety of cell functions.
Wednesday, May 13, 2015
Mouse Study Reveals Potential Clue to Extra Fingers or Toes
NIH-funded study finds that gene appears to regulate protein signals inside the cell.
Tuesday, December 02, 2014
Scientific News
Key to Natural Detoxifier’s Reactivity Discovered
Results have implications for health, drug design and chemical synthesis.
New Protein Found in Immune Cells
Immunobiologists from the University of Freiburg discover Kidins220/ARMS in B cells and demonstrate its functions.
Cell's Waste Disposal System Regulates Body Clock Proteins
New way to identify interacting proteins could identify potential drug targets.
How a Molecular Motor Untangles Protein
Diseases such as Alzheimer’s, Parkinson’s and prion diseases, all involve “tangled” proteins.
Compound Doubles Up On Cancer Detection
Researchers have found that tagging a pair of markers found almost exclusively on a common brain cancer yields a cancer signal that is both more obvious and more specific to cancer.
How Cell Growth Triggers Cell Division
Researchers in Jan Skotheim's lab have discovered a previously unknown mechanism that controls how large cells grow, an insight that could one day provide insight into attacking diseases such as cancer.
Probing the Forces Involved in Creating The Mitotic Spindle
Scientists at The Rockefeller University reveal new insights into the mechanical forces that govern elements of the mitotic spindle formation.
Identifying Cancer’s Food Sensors May Help to Halt Tumour Growth
Oxford University researchers have identified a protein used by tumours to help them detect food supplies. Initial studies show that targeting the protein could restrict cancerous cells’ ability to grow.
Specific Variations in RNA Splicing Linked to Breast Cancer
Researchers have identified cellular changes that may play a role in converting normal breast cells into tumors. Targeting these changes could potentially lead to therapies for some forms of breast cancer.
Thousands of Protein Interactions Identified
Thanks to the work by Utrecht University researcher Fan Liu and her colleagues, it is now possible to map the interactions between proteins in human cells.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
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
2,600+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,800+ scientific videos