Aging Research Update: Scientists Identify 238 Genes Linked To Increased Lifespan

young and old
Scientists have identified 238 genes that, when removed, increase the lifespan of yeast cells; potentially some of these may be instrumental in the human aging process. Niko Knigge, CC by 2.0

Though we are well-acquainted with the aging process of our own bodies, only the scientists among us ask: What is happening on the cellular level? A new study has identified 238 genes that, when removed, increased the lifespan of yeast cells (specifically their ability to continue replicating themselves). While yeast cells may be a far cry from human cells, many of the cellular mechanisms found in their genes continue on, surprisingly enough, through higher organisms including human beings.

Importantly, 189 of these genes have never before been linked to aging. Someday, then, this valuable research may be applied to human health.

Lifespan Genes

The study began with an examination of 4,698 separate yeast strains, each with a single gene deleted. The researchers designed the study to answer a simple question: Which of the strains increased lifespan? And so they observed and recorded the entire life cycle of each microscopic strain. Every time the mother divided, the researchers used a needle (attached to a microscope) and teased out the daughter cells, and then counted how many times each of these new cells divided.

This detailed work, funded by the National Institutes of Health, was performed by the laboratories of Dr. Brian Kennedy, lead author and the Buck Institute's president and CEO, and Dr. Matt Kaeberlein, a professor in the department of pathology at the University of Washington.

Their painstaking efforts showed how different genes (or the absence of them) modulated the aging of yeast. For example, one gene called LOS1 appeared to have a particularly strong impact on lifespan.

LOS1 is known to be modulated by mTOR, a growth regulator inside each cell that, based on nutritional and environmental cues, helps to orchestrate energy levels, stress, growth, and amino acids — key factors associated with a cell's calorie use and lifespan. In turn, LOS1 influences a gene, Gcn4, that helps modulate DNA damage control. LOS1 also helps relocate transfer RNA, which performs the job of transporting amino acids to ribosomes in order to help build proteins, the worker bees of a cell.

Because a number of the genes identified by Kennedy and Kaeberlein are found in C. elegans roundworms, this suggests some of the same mechanisms may exist in higher organisms, possibly even humans.

“Many of the longevity genes identified here are known to act in longevity pathways conserved in multiple species,” wrote the authors. “...Others, like the LOS1 pathway, are largely unstudied.”

Source: McCormick MA, Delaney JR, Tsuchiya M, et al. A comprehensive analysis of replicative lifespan in 4,698 single-gene deletion strains uncovers conserved mechanisms of aging. Cell Metabolism. 2015.

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