In Linhua Wang’s ideal world, all humans would be a little more like bats.
Wang, a biochemist and zoonotic disease expert at Duke-NUS School of Medicine in Singapore, harbors fantasies of people flying through the air and echolocating to find the best burger in town. do not have. The point is “don’t do it” live “Like bats,” Wang told me, drawing inspiration from their very strange physiology to improve the quality and even longevity of human life. Although it may not seem like it to them, bats are “the healthiest mammals on the planet,” Wang said.
Given bats’ recent track record, this idea may be difficult to correct. Over the past 30 years, from 1994, when Hendra virus infected humans, to 2019, when SARS-CoV-2 emerged, at least some of the most devastating virus outbreaks known to have recently jumped from wild animals to humans have occurred. Six cases are most likely of bat origin. But bats themselves seem to rarely, if ever, get sick. Ebora, Nipah, marburg, and the various coronaviruses don’t seem to bother them.Some bats can survive encounters rabies, if left untreated in humans, the mortality rate is nearly 100%. “They have evolved mechanisms to limit the impact of disease,” says Emma Teeling, a bat biologist at University College Dublin who collaborates with Wang.
This creature’s apparent ability to refuse death goes even further. Some nectar-eating species spend years sucking on nectar. Blood glucose level is high enough Although it puts humans into a hyperglycemic coma, the bats don’t seem to develop what’s called diabetes.Other survivors have been recorded Up to 41 years in the wild— nearly 10 times the lifespan typically expected for a mammal of that size — all the while. cancer and fertility declines.
Mr. Wang and Mr. Teeling, along with several colleagues, recently won a $13 million grant The European Research Council is trying to better understand the biology behind these bat abilities, and how it helps other creatures. (and they certainly are That’s not all ) Wang’s team is already testing some of his ideas by genetically engineering people to be healthier and more resistant to disease, as he cheerfully likes to boast.bat rat” It will still be many years before he and his colleagues will be able to create any kind of bat. ManBut they believe this idea could one day lead to new treatments for humans to fight diabetes, relieve infections and even extend lifespans.
The key to bat health appears to be flight, or at least its effects. Evolve There is a fly on the bat body. Flight, despite all its perks, is one of the most energetic. burdensome Transportation: When bats fly, their metabolism increases. Up to 15-16 times Above rest.heart rate may increase rapidly Over 1,000 beats per minute; their body temperature can Above 105 degrees Fahrenheit, the animal is effectively hyperthermic. If we apply all this to other mammals, their bodies can be overwhelmed by the flames of extreme inflammation, and the toxic byproducts of their metabolism can effectively tear apart their cells.
To cope with this self-destructive form of locomotion, bats have evolved two important safeguards. First, they are very good at maintaining physical zen. Even when pushed to extreme exercise, bats’ bodies do not become inflamed as much. Not enough Part of the molecular machinery that turns these systems on.So the bats just flock together. less damage When your body feels stressed. And for that damage, do Bat cells appear to be unusually efficient in: cleaning and repairrapidly piecing together torn pieces of DNA.
These strategies, Wang and Teeling told me, not only made it easier for bats to fly. It also reduces other types of harm to the body. Cancer tends to develop when errors appear in specific parts of the genetic code. And, molecularly speaking, aging is essentially what happens to your body as cellular wear and tear accumulates throughout your life. In a sense, stress is just stress. The root cause of these chronic health problems overlaps with our biggest tax: avoidance. Therefore, a solution that keeps the bat body running smoothly in the air can address issues throughout the life of the bat. As humans age, our ability to repair damage decreases, but bats’ ability improves, Teeling said.
All of this also helps explain why bats are such favorable hosts for pathogens that can kill us. Many of the most dangerous cases of infection are caused by the body’s excessive inflammatory response. That response can pose a greater threat than any damage the pathogen itself may cause to cells. Many of our defenses are like bombs placed on our home base, which can certainly kill the invaders, but at great cost to us. Bats have a very high threshold for inflammation, so it appears that many viruses can live in bat tissues without causing too much destruction. In laboratory experiments, bats have been given so much virus that their tissues are packed to the brim, about 10 million units of Ebola virus per milliliter of serum, or about 10 million units of MERS coronavirus per gram of lung. has been detected.It was still there Failing to identify serious health problems in bats. Tony Schonz, a bat immunologist at Colorado State University, says bats and their viruses are effectively creating an “immunological détente.”
Such astronomical levels of viruses are not a desirable condition for bats.There also happens to be a dead bat. Very good at inhibiting viral replication in front. Part of the reason, Wang told me, is that part of the antiviral defense system appears to be “always on” in the bodies of certain bat species. “I call them ‘combat ready.'” do When they spawn, they attack hosts that are already overrun. Powerful ready-to-use protein It blocks part of the virus’ life cycle and prevents microorganisms from getting out of control.
The catch here is that the virus is cleverly exploiting the bat’s tricks, trying to enter well-protected cells to replicate and spread between cells, thus evolving to become more powerful. That’s what I’m doing. And bat-level attack power could be excessive for humans who don’t have the same shield, says Carla Brook, a disease ecologist at the University of Chicago.it might help explain Why are bat viruses so common? hit us so hard.. Couple the difficulties we have in controlling our own inflammation, and what might have been a minor infection for bats can turn into a complete mess for humans. there is.
One of Wang’s main ideas for dealing with this kind of host-pathogen mismatch is to use drugs to suppress the inflammatory response a little more, in other words, to make it a little more bat-like. That option is particularly interesting, he told me. Because it may also lower the risk of autoimmunity and perhaps even prevent aging and certain chronic metabolic diseases. His bat rat was designed to express a specific emotion. Bat gene that suppresses inflammationhas conducted experiments using this principle, and it appears to be effective against influenza, SARS-CoV-2, and even gout crystals.
But the idea of reducing inflammation is not entirely new. Our medical arsenal has included steroids and other immune system-modulating drugs for decades. Arinjay Banerjee, a virologist and bat immunologist at the University of Saskatchewan, said all treatments have limitations and drawbacks, and bat-inspired treatments in particular may require similar attention. They say it’s expensive. Inflammation, however harmful, is an essential defense. Drugs that change it, especially those taken long-term, must avoid the following harms: excessively while avoiding the risk of not enough. And humans are not bats, after all. Hanna Frank, a bat immunologist at Tulane University, said that implanting bat defenses into humans might not work the way researchers hope. To truly realize bat-like effects in humans, Banerjee said, multiple treatments that turn multiple physiological dials are likely needed.
Researchers are learning more about bats, but gaps in knowledge remain large. What he observed in one of the more than 1,400 species of bat may not apply to others. Additionally, no one can say exactly what optimal health for bats is because their physiology is so different from ours, Frank said. Bats rarely die from viruses, Brooke said, but these infections may be taking a toll in ways researchers aren’t yet aware of. Bats aren’t the only interesting vectors of viruses.Lots of rodents roam around too. deadly pathogen As Schontz points out, you won’t get sick. They are also not the only mammals that live in extreme environments. Naked mole rats tolerate low oxygen conditions underground. When seals dive, they must withstand pressure that crushes their organs. Similar to flight, these adaptations may recalibrate immunity in as-yet unknown ways.
But it’s true that bats give us a lot more than many people realize they give us. Years ago, right after the Hendra virus outbreak in Australia, a politician said to me: Let’s bomb the bats‘ said Mr. Wang to me.of The beginning of the coronavirus pandemichas sparked calls for bats to be culled. Some animals were even reportedly burned from their roosts. “I don’t want a bat as a pet yet,” Wang told me. But if his discoveries continue on track, people may one day associate bats with traits that make us healthy, rather than with diseases we don’t want to contract.