Bats may be synonymous with Halloween, but the spooky creatures could hold the key to ageing.
The nocturnal mammals have long fascinated scientists, with bats living well beyond what would be expected given their small size.
Bats can even harmlessly harbour infections, like Ebola and the coronavirus, which can be deadly in humans.
To better understand the secret to bats' good health, scientists from University College Dublin (UCD) have been analysing the blood of the longest living of the animals – Greater Mouse-eared bats – from infants to old age.
The team focused on the mammals' telomeres, protective caps that prevent DNA from deteriorating. Results suggest bats increase their ability to repair damaged genes with age, a process that diminishes in humans.
Giving a human the immune system of a bat would even prevent them from ending up on a ventilator with the coronavirus, according to the scientists.
One expert "firmly believes" the animals hold the key to us having longer, healthier lives, with a bat-mimicking drug potentially being available within the next 10 years.
Some bat species famously suck blood, just like the immortal Dracula.
"Maybe it's all in the blood," geneticist Professor Emma Teeling, who studies bats at UCD, told AFP.
The laws of nature generally state that the bigger the animal, the longer its lifespan, with mice generally surviving just one year, versus up to seven decades among elephants.
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Bats appear to be an exception, however, with some living to 15.
To better understand the animals' mysteriously long lifespan, Professor Teeling studies the blood of microchipped bats that dwell in rural churches and schools in Brittany, France.
Every year, the UCD scientists go to the bats' roosts, taking a little bit of blood from both the newborns and older animals.
"We're taking a little bit of blood, but rather than us being the vampires to the bats we're making them give us their secrets," said Professor Teeling.
The scientists have found that as the bats age, their ability to repair damaged DNA increases.
The animals can also balance their immune response. In humans, coronavirus complications are thought to partly come about when their immune system over-reacts, triggering widespread inflammation.
Transplanting a bat's immune system into a human would keep the latter safe amid the pandemic, according to the scientists. Give a human the immune system of a mouse and they will end up on a ventilator, they added.
Perhaps surprisingly, the genetics of humans and bats are relatively similar, with the latter having slight modifications.
If scientists discover the gene that helps bats to live into old age, a mimicking drug could be given to humans.
When it comes to anti-ageing, Professor Teeling said: "I firmly believe it [the key] lies in studying bats."
Such a drug may be available in just 10 years, however, the geneticist pointed out how fast new treatments are being developed.
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The UCD team is not the first to study bats' medical potential.
In 2020, scientists from the University of California, Berkley, took cells from the Egyptian fruit bat and Australian black flying fox, as well as from an African green monkey, which acted as the "control".
The Egyptian fruit bat is a "host" for the Marburg virus, an Ebola-like infection with a 24% to 88% death rate. Australian black flying fox bats are hosts to the Hendra virus, which can cause "severe and often fatal disease in humans".
The monkey cells were "rapidly overwhelmed and killed" when exposed to "viruses mimicking Ebola and Marburg". In contrast, the bat cells "successfully walled themselves off from viral infection".
Writing in the journal eLIFE, the scientists put this down to the bat cells "flooding" themselves with the infection-fighting protein interferon, which the monkey cells did not produce.
Bats are thought to have evolved to release high amounts of interferon to "mop up" the inflammatory damage caused by flying. The nocturnal creatures may therefore be "primed" to defend themselves against viruses.
"Our immune system would generate widespread inflammation if attempting this same antiviral strategy," said study author Cara Brook.
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