Lifespan May Be Determined by the Size of a Tiny Part of the Cell

You're going to wish you paid attention in high school biology. 

If it was possible to know how long someone is destined to live, would it be possible to resist taking a peek at it? A review published this year in Cell Biology tempted us with that information. The length of a person’s life, they argued, could very well be determined by the size of one key part of every human cell.

We’re already aware of a few key markers that indicate how fast cells — and the organisms that are composed of them — age. The most famous is the length of telomeres, the tiny nubs at the end of chromosomes that shorten as we age. There are also genes that seem to impact other processes of aging. But this April, Adam Antebi, Ph.D., the director of the Max Planck Institute for Biology of Aging, and postdoctoral fellow Varnesh Tiku, Ph.D., identified the a part of the cell called the nucleolus as another important indicator of how long a person might live.

This story is #3 on Inverse’s 25 Most Surprising Human Discoveries Made in 2018.

nucleolus
The smaller the  nucleolus (green) the longer the organism seems to live 

To find the nucleolus, you have to zoom way into a cell. At the heart of every cell is the nucleus, where most of our DNA is stored, but at the center of the nucleus is the nucleolus. Its usual role is to help the cell perform some basic housekeeping functions, but Antebi and Tiku believe that its physical size could affect how long an organism lives. In their paper, they reviewed studies on nucleolus size in humans, worms, yeast and mice and found that, across species, smaller nucleoli were associated with longer lifespans.

They’re still not sure why this connection exists, though Antebi speculated in an interview with the New York Times that small nucleoli might simply be more efficient than their bigger counterparts, which seemed to be associated with diseases like cancer. In the review, Antebi and his team suggest that a place to start investigating this connection is by examining the function of a gene called NCL-1, which appears to regulate how the nucleolus functions. Previous studies have shown that animals with longer lifespans seem to have both smaller nucleoli and higher NCL-1 activity.

If they’re able to actually find what causes the connection between nucleolus size and lifespan, it might open up new ways that scientists can intervene in the aging process. This work is already underway when it comes to telomeres; come 2019, the nucleolus might be another avenue of attack in our ongoing battle against mortality.

As 2018 winds down, Inverse is highlighting 25 surprising things we learned about humans this year. These stories told us weird stuff about our bodies and brains, uncovered insights into our social lives, and illuminated why we’re such complicated, wonderful, and weird animals. This story was #3. Read the original story here.