DEC 20, 2018 04:50 PM PST

Identifying Molecular Markers of Aging

WRITTEN BY: Carmen Leitch

As people get older, some remain healthy while others begin to get chronically ill. There are many factors like lifestyle choices and environmental influences that we know play a role in whether people stay healthy as they age, and there are other contributors that are unclear. Researchers at the Salk Institute wanted to know more about molecular markers that might indicate who will age better than others. These markers could also be useful for treating health conditions that are related to old age, like dementia or heart disease. Their findings have been reported in Genome Biology.

Image credit: Pexels

"This experiment was designed to determine whether there are molecular signatures of aging across the entire range of the human lifespan," explained co-senior author Saket Navlakha, an assistant professor in Salk's Integrative Biology Laboratory. "We want to develop algorithms that can predict healthy aging and non-healthy aging, and try to find the differences."

"The study provides a foundation for quantitatively addressing unresolved questions in human aging, such as the rate of aging during times of stress," added the co-senior author of the study, Professor Martin Hetzer, Salk's vice president and chief science officer.

For this work, the researchers utilized dermal fibroblasts, a skin cell type that helps heal injuries and generates connective tissue; these cells are easy to harvest with a non-invasive biopsy, and earlier studies have suggested that they probably carry aging markers. While many of our cells are constantly renewing, some of these dermal fibroblasts stay with us for our whole lives.

The scientists obtained fibroblasts from 133 healthy people, from age one to 94, with an average of thirteen individuals from every decade. After culturing the cells and sequencing the RNA they contained, the researchers could assess which genes were active, and find biomarkers that change throughout life. Machine learning and custom algorithms sifted through the data generated from the RNA sequencing (RNA-Seq) data. They identified biomarkers that could predict a person’s age, with an error of eight years.

A human fibroblast cell line was derived from a skin biopsy. To confirm cell identity, staining was performed for a fibroblast marker (SERPINH1, magenta), nuclear pore complexes (Nup153, yellow) and DNA (DAPI, blue).  CREDIT Roberta Schulte/Swati Tyagi/Salk Institute.

"The fact that our system can predict this kind of aging shows that this model is starting to get at the true underpinnings of biological age," said first author Jason Fleischer, a Salk postdoctoral fellow. "

"We took a 'kitchen sink' approach with this project. Rather than going into this research with an idea of what we wanted to find, we decided to look at the changes in expression of all the protein-coding genes and let the algorithms sort it out. We used what's called an ensemble machine-learning method to do this.”

The researchers took advantage of a large dataset to assess changes that occurred throughout the entire genome, an approach that’s different from some others. The data has also been made publicly available.

The team cautions that something may predict aging, but that doesn’t mean it’s causing aging. It could help doctors screen for age-related biomarkers, however, and counsel patients about their lifestyle choices. More research remains before that’s possible, however.

"Aging is a driver of so many diseases, including Alzheimer's and other neurologic problems," Navlakha concluded. "If we are able to show that the changes we've seen in fibroblasts are connected with aging in other types of cells, we may eventually be able to use these signatures to develop targeted interventions."

Learn more about healthy aging from the video above by Harvard Medical School.


Sources: AAAS/Eurekalert! via Salk Institute, Genome Biology

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JAN 18, 2020
Cell & Molecular Biology
JAN 18, 2020
Linking Intestinal Stem Cells with Increased Cancer Risk From a High-Fat Diet
The work, which used a mouse model, links stem cell activity with cellular fat consumption in a new way....
JAN 18, 2020
Cell & Molecular Biology
JAN 18, 2020
Time-Restricted Eating Improves Symptoms of Metabolic Syndrome
Occasional fasting has been linked to a variety of health benefits....
JAN 18, 2020
Drug Discovery & Development
JAN 18, 2020
Could the diabetic drug 'metformin' extend a healthy lifespan?
The most commonly prescribed diabetic medication for the Type 2 condition is ‘Metformin’—a drug with a mysterious mechanism of action but...
JAN 18, 2020
Microbiology
JAN 18, 2020
Viruses Can Escape the Effects of CRISPR by Shielding Their Genomes
Our world is filled with microbes, and in every kind of environment, they compete for supremacy, a competition that dates back to the origins of life....
JAN 18, 2020
Genetics & Genomics
JAN 18, 2020
A New Type of Muscle Cell That Could be a Target for Gene Therapy is ID'ed
Muscles have a supply of restorative stem cells called satellite cells, and now they have identified a new type....
JAN 18, 2020
Neuroscience
JAN 18, 2020
Amyloid Plaques May Not Come First in Alzheimer's
It’s commonly thought that excessive build-up of amyloid plaques, destroying the connections between nerve cells, is the first sign of Alzheimer&rsqu...
Loading Comments...