Bats live remarkably long, healthy lives for being such small creatures, and researchers at the University of Vermont are part of an international team that says they’ve discovered a key reason why. They say their findings could someday help humans live longer, healthier lives too.
“Because bats are exceptional in these ways, it tells us something about how extreme longevity can evolve,” said Vermont researcher Elise Lauterbur, a co-author on the new study, published in the science journal Nature.
The secret to bats’ longevity lies in their genes, the researchers say, and in their immune systems — specifically, in how their bodies respond to viral infections.
Some kinds of bats can live for decades. Most similarly long-lived mammals like humans regularly succumb to cancer, but bats do not.
“They just don't seem to turn up with tumors like you would expect of something that is living an extremely long time, and has cells continuing to divide, and eventually those processes start to degrade and allow cancers to crop up,” Lauterbur said.
To learn more about how the bats avoid disease, the scientists mapped the genomes of eight closely related bats found all over the world, with very different lifespans.
Some of the bats they studied live for just three years. Others, like the endangered little brown bat, which is native to Vermont and weighs on average just 5 grams, can live for 40 or more years.
That, Lauterbur says, is like a human being living for a thousand years or more without becoming frail or succumbing to age-related disease.
The scientists wanted to understand what small differences between these animals might be responsible for the little brown bat’s exceptionally long lifespan and good health.
To do this, they biopsied tiny circular patches of skin from the bat wings. Study co-author and Penn State University geneticist Juan Manual Vazquez then grew cells from the sample in the lab and mapped the animals’ genomes.
From there, the scientists exposed the lab-grown bat cells and cells of other mammals to viruses and things known to cause cancer.
They discovered that longer-lived bats had multiple copies of certain genes related to the immune system that most mammals have just one of, and that this appears to help them live longer and fight off cancer.
Long-lived bats, Lauterbur says, are also uniquely good at finding and getting rid of or abandoning cells with damaged DNA, such as cancer cells. The researchers believe this makes them resistant to many viruses and aging-related diseases.
When a virus infects an animal, it sometimes breaks or damages some of the host’s genes. Having multiple copies of certain genes that are critical for directing immune response appears to allow bat immune systems to essentially keep an arsenal of defenses tucked away in their cells.
The researchers say the findings could be helpful to scientists exploring whether gene therapy — the process of editing genes — could be used to treat cancer and other aging-related diseases in humans.
“What we're seeing here is that any given gene that might potentially, in the future, get tweaked to reduce cancer risk — well, that gene probably also has a role in contributing to something to do with longevity. It probably also has a role in dealing with viruses or pathogen response,” Lauterbur said.
So, they say, consider that the tiny bat flying around outside your home at night eating bugs might just have superhuman resistance to cancer that could someday save people, too.
