Scientists study bats' longevity and viruses
HONG KONG — Count Dracula was onto something. Bats.
The immortal Prince of Darkness has been associated with the flying mammals since he first flitted through Bram Stoker's 1897 novel. Now, scientists seek to unlock another trait the vampire shares with bats: the secret of longevity.
The volume of published scientific research on bat viruses has doubled in the past decade with the discovery that they're probably a natural reservoir for global killers such as Ebola, severe acute respiratory syndrome and the Middle East respiratory syndrome. Along the way, scientists have been startled by how well they respond to the genetic wear and tear that's a feature of life, aging and diseases such as cancer.
“The most outstanding difference we've seen between bats and other mammals has to do with DNA repair,” said Linfa Wang, 53, director of the emerging infectious disease program at the Duke-NUS graduate medical school in Singapore. “If the science is as true as we think it is, we can unlock the mechanisms and it can have a huge, huge impact.”
Wang, dubbed by some colleagues the “Bat Man,” was awarded a grant in April from the National Research Foundation of Singapore and is hiring a team of 10 researchers to study the animals' genomics.
How some species can live three times longer than other mammals their size may be linked to their ability to carry viruses that are deadly to other animals, as well as their low rates of cancer, he said.
It's a positive spin for a group of mammals that's suffered from negative connotations in Western culture for centuries: from bat-winged demons in medieval Christian imagery, to a modern association with rabies and other viruses.
The ability to fly means bats can spread zoonoses — diseases that transmit from vertebrate animals to humans — across the globe.
Flight may make bats a threat. It may also be their biggest gift. As people globally live longer lives, diseases related to aging and cell damage, such as cancer and Alzheimer's, are a growing scourge.
Metabolic activity and environmental factors cause damage to DNA in humans. Wang said that newborn babies have almost homogeneously healthy cells, while a 70-year-old may have damage in 90 percent of his mitochondria — structures inside cells that produce energy.
Bats' cells are adapted to survive surges in metabolism — their hearts can go from 10 beats per minute during hibernation to 1,000 beats in flight. A similar change in humans would create a lethal shortage of oxygen and oversupply of toxic by-products of the metabolic process that damage DNA.
“So everything is interlinked,” Wang said. “Bats' ability to do better with DNA damage repair, live longer, have less cancer, carry viruses without disease — we think this is all a different display of the same thing.”