How bats could hold the key to human health – and slow the ageing process
Batman may not have any special superpowers, but he has proved remarkably resilient and lived a long time. Created way back in 1939, he’s never come down with anything nasty like Ebola, Marburg or Covid, and has certainly never suffered from more common inflammatory conditions such as heart disease or arthritis.
We mention this because scientific truth may be about to get a whole lot weirder than fiction. Bats, the furry but not so cute flying mammals, have more than once threatened human civilisation with lethal viruses. But now they may be about to save us – to extend our life spans by giving us the power to fend off even the most pernicious of pathogens.
A “bat-mouse chimaera” model, which exhibits signs of such superpowers, already exists and if things go well, batpeople (he, she or they) could be next. Indeed a powerful bat protein known as “bat ASC2” is already being tested on human cells at a high security lab in Singapore, a city-state that is not dissimilar to Gotham, albeit much cleaner and rules based.
The breakthrough, published yesterday in the journal Cell, has been led by Dr Linfa Wang, a professor of emerging infectious diseases at Duke-NUS Medical School in Singapore, and one of the world’s foremost authorities on bats.
It shows that a protein carried by bats could hold the secret to slowing the human ageing process and combating inflammatory diseases as diverse as Covid-19, heart disease and arthritis. Further, it demonstrates the protein appears to work in transgenic mice, cutting their vulnerability to dying from flu by up to 50 per cent. “Our results demonstrate an important mechanism by which bats limit excessive virus-induced and stress-related inflammation with implications for their long lifespan,” said the study’s authors.
They added that when the bat ASC2 (only slightly different from our own) was tested on human cells they too became more resilient, demonstrating its “therapeutic potential”. The study’s findings “provide new insights and strategies to combat ageing and inflammatory diseases in humans”, they concluded.
It was Prof Wang who, in 2005, was part of the team that first discovered that bats were the natural reservoir of Sars viruses. That discovery did not come in time to prevent the Covid-19 pandemic, but it did bolster the early research on Sars vaccines by teams like the one in Oxford – something that paid dividends when Sars-CoV-2 broke out.
The professor, together with many other scientists around the world, is keenly interested in bats not just because they carry so many lethal pathogens, but also because they carry those viruses without themselves suffering any ill effects. Be it Ebola, Marburg, Mers, Covid, Nipah or countless other nasties, bats can fly about with them for decades without ever suffering so much as a cough or a haemorrhage.
And bats have another, not unassociated, fascination for scientists. They live extremely long lives, some of the little critters living for up to four decades. Forty may not seem a big number but in bat years it’s phenomenal and runs directly counter to the “rate of living theory” which postulates that the faster an animal’s metabolism, the shorter its life.
Bats, of course, have one of the fastest metabolisms on the planet, their heavily muscled wings and nights spent flying requiring a metabolic rate that is three to five times greater than the maximum observed during exercise in similar-sized mammals.
So why can bats tolerate so many viruses? Well, the new paper says that the protein ASC2 is the key. It’s a genetic adaptation in the “inflammasomes” of bats which appear to protect the animals against the ill effects of a normal inflammatory response. Humans have ASC2 as well but it is slightly different, the bat version having evolved differently over millions of years. Prof Wang hypotheses this happened because bats are the only mammal capable of flying, putting their bodies under huge physiological stress and forcing an evolutionary change. “Since bats are the only mammals with powered flight, the metabolically costly flight might be one of the key drivers for this adaptation,” the report said.
Significantly more sedentary than bats, humans do not have such powerful ASC2 – not yet anyway. This means our immune response kicks in much sooner. While this is often a good thing – a sign our immune system is working – it also has serious drawbacks. Sometimes, as with some cases of Covid or in the 1918 Spanish Flu, a virus sets the human immune response into overdrive, triggering a “cytokine storm”. This acute, often uncontrollable inflammatory response can be deadly, killing not just the invading virus but us too.
So what are the chances of us becoming bat people, inflammatory-resistant bat-human chimaera like the bat-mice Prof Wang and colleagues have cooked up in their Singapore laboratory? The answer, thankfully, is low but we may still get the benefits of bat ASC2 in a medicinal form in years to come.
Much more research is needed, but Prof Wang’s team are so excited about the potential of their discovery for the creation of drugs to combat the negative effects of the human inflammatory response, that they’re already working on several treatments. “We have filed patents based on this work and are exploring commercial partnerships for drug discovery,” he told the Telegraph. “We are hoping to develop a new class of anti-inflammatory drugs for inflammasome-driven human diseases.”
Others caution that new anti-ageing or anti-inflammatory drugs are still some time away. “Bats are fascinating mammals,” said Prof Gilda Tachedjian, head of life sciences at the Burnet Institute in Australia, but they are not the same as humans, and nor are mice. “While the findings of this study are intriguing, more work is needed to translate these findings into new therapies that can be used in people to reduce mortality from viruses or increase longevity.”
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