JUL 16, 2018 08:44 AM PDT

Preventing Aging by Protecting Ribosomes

WRITTEN BY: Carmen Leitch
2 5 327

As time and exposure to the elements wear organisms down and at the cellular level a gradual deterioration occurs, aging happens. Scientists have now learned more about a protein that helps protect cells from senescence, the loss of vitality and reduction in growth that accompanies the degradative processes of aging. The protein, SIRT7, can help shield a group of vulnerable genes from damage. This work, by researchers at the VA Palo Alto Health Care System (VAPAHCS), has been reported in the Journal of Biological Chemistry.

In the absence of SIRT7, a human primary cell displays multiple nucleoli. DNA was stained with DAPI (turquoise) and nucleolus was stained with anti-fibrillarin (red). / Credit: Silvana Paredes

Proteins are essential components of tissues and organs and are critical parts of the cell that are often in high demand. That makes ribosomes, the protein-making factories of the cell, extremely important and well-used. There tend to be many copies of the genes that encode for the ribosome, and many of those genes remain silent until they are needed. If genes that normally code for the ribosome become damaged or unstable, the backup genes can kick in and start doing their job. That redundancy is critical because the DNA encoding for ribosomes (rDNA) often becomes rearranged and mutated.
 
"Ribosomal DNA is one of the major hotspots for instability in the genome," explained the leader of this research, Silvana Paredes.

In the lab of Katrin Chua, which is associated with both Stanford and the Geriatric Research Education and Clinical Center at the VAPAHCS, the researchers investigated the connections between rDNA, aging, and the SIRT7 protein. Normally, SIRT7 acts to change histones, which help DNA organize properly; that allows the right parts of the genetic material to be exposed at the correct times, activating the proper genes. Paredes discovered that SIRT7 was critical to the regulation of rDNA; it keeps portions of it turned off.

If SIRT7 is removed from a cell, the scientists found that rDNA genes suffer damage; they stop dividing and show signs of aging. That indicates that SIRT7 is critical to preventing age-related cellular deterioration. In disorders like diabetes, arthritis, cancer, heart disease, and neurodegeneration, cells that are senescent (exhibiting the signs of aging) tend to accumulate. Removing those cells could have a therapeutic effect. Finding a way to keep SIRT7 active may also help researchers maintain cellular health.

"By identifying rDNA instability as an underlying trigger of senescence of human cells and demonstrating the central role of SIRT7 in protecting against this process, our studies not only provide important insights into basic mechanisms of aging but also identify potential molecular targets for aging-related disease processes," Chua concluded.

This video from the Mayo Clinic briefly describes an unrelated study in which scientists removed senescent cells from mice, and saw a dramatic lengthening of the lifespan of those research models.

Sources: AAAS/Eurekalert! Via American Society for Biochemistry and Molecular Biology, Journal of Biological Chemistry

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
JUN 17, 2018
Cardiology
JUN 17, 2018
Microtubule Intervention to Reverse Heart Disease
Changes in the cellular structure of heart muscle cells have a large impact: past and present studies show that these types of changes can lead to heart fa
JUL 04, 2018
Microbiology
JUL 04, 2018
Revealing How Gut Bacteria can Impact our Health
Our GI tract pays host to trillions of microbes, which have been shown to play a highly influential role in our health and well-being.
JUL 11, 2018
Microbiology
JUL 11, 2018
New Insight Into Bacterial Pathogenicity
Scientists have learned how some pathogenic bacteria stick to cells in the intestine, which gets their infection started.
JUL 28, 2018
Cell & Molecular Biology
JUL 28, 2018
Self-organizing Synthetic Tissues are Getting More Complex
All the structures in the body arise from a fertilized cell, and scientists are learning more about how that happens.
AUG 04, 2018
Cell & Molecular Biology
AUG 04, 2018
Bioengineered Lung Successfully Grown and Transplanted
The complexity of human organs has made them difficult to engineer, but real progress is being made.
AUG 05, 2018
Genetics & Genomics
AUG 05, 2018
Newly ID'ed Lung Cell Changes Our Understanding of Disease
This rare type of cell seems to play a major role in cystic fibrosis.
Loading Comments...