In Linfa Wang’s perfect world… humans are like bats

Humans and bats

Wang, a biochemist and biopathologist, didn’t envision humans flapping their wings in the sky or using echolocation to find the best burger in town. Improve and extend their lives through their peculiar physiology. “It may not be obvious to them, but bats are the healthiest mammals on Earth,” Wang says.

Given the bats’ long recent record, that may seem hard to convince; In the past three decades, from 1994, when “Hendra virus” was transmitted to humans, to 2019, when the “SARS-CoV-2” outbreak occurred, the emergence of about 5 deadly epidemics transmitted to humans by bats. Wildlife.

But bats rarely get sick, because “Ebola,” “Nipah,” “Marburg” and all kinds of coronaviruses do not affect them, and they are able to escape the disease. 100% mortality rate in humans if untreated.

Developed mechanisms to resist death

“Bats have evolved mechanisms to limit disease damage,” explains bat biologist Emma Tilling of University College Dublin, who works with Wang.

The ability of these creatures to resist death goes even further. Some honey-eating species spend years raising blood sugar levels high enough to cause a diabetic coma in humans, even though they show no signs of diabetes. Research indicates that others live up to 41 years outdoors; That means ten times the life expectancy of mammals of the same size, and without suffering from cancer or reduced fertility.

Wang, Tilling and their colleagues recently received a $13 million grant from the European Research Council to try to better understand these bat abilities and how they might help other species.

Invention of the “Man-Bat”.

Wang’s team began testing some of their ideas by genetically engineering a healthy, disease-resistant bat. Wang and his team are still several years away from developing a “human bat,” but they believe the ideas could one day be the source of new treatments for humans to fight diabetes, suppress infectious diseases and extend life.

In practice; Flight, or at least its effect on the body of bats, appears to be a major factor in the superior health of these creatures. Flying is one of the most demanding transportation options in terms of energy consumption, as bats fly; Her metabolic rate rises to 15 or 16 times her resting rate, her heart rate soars to more than a thousand beats per minute, and her body temperature rises above 40 degrees Celsius, sending her into a sickly fever.

If we imagine any other type of mammal in this situation, its body would no doubt be exhausted by severe inflammation.

To cope with this destructive movement, bats have developed two basic defenses: the first is their excellent ability to maintain physical stillness; Even when these organisms are subjected to extreme stress, their bodies maintain a reasonable temperature. This may be because bats lack some of the molecular mechanisms that operate these systems.

In other words, bats suffer less damage after their bodies are exposed to stress. When damage occurs, bats have another trick: their cells are incredibly efficient at maintaining and rapidly repairing their damaged DNA.

Mitigating Physical Ailments Wang and Tilling point out that these techniques also contribute to the alleviation of other physical ailments. Human cancers develop after errors appear in specific regions of the genetic code. At the molecular level, aging is the primary result of the accumulation of cellular losses and complications over the years.

In bats, stress is a stressor, meaning that the main causes of these chronic health problems can be addressed by flying and all associated stressors. In other words, solutions that allow the bat’s body to fly smoothly through the air will help solve its health problems throughout its life. While humans’ efficiency at repairing damage declines with age, bats’ abilities steadily improve, says Tilling.

Prevent infection

This information may help explain why bats are good hosts for pathogens that kill humans.

In humans, the body’s excessive inflammatory response increases the risk of infectious diseases. This response poses a greater risk than any damage an infectious pathogen may cause to the cells of the human body. Our defenses are like bombs installed at the doors of our homes, which are capable of eliminating invaders, but at a very high cost to our bodies.

On the contrary; Bats have a high threshold of protection before inflammation erupts; Many viruses appear to be able to inhabit their cells without causing this level of destruction.

During laboratory experiments, scientists injected bats with so many viruses that their tissues overflowed (it reached 10 million units of the “Ebola” virus per milliliter of solution, and 10 million units of the “Corona” virus per gram of lung). Researchers have not been able to identify any health-threatening problems for the bats. Tony Sants, an expert on bat immunity at Colorado State University, believes that bats and their viruses have reached a state of “immune immunity.”

But this massive amount of viruses is not a preferred situation for bats, and of course, their bodies are very adept at preemptively suppressing the spread of viruses. That’s in part because some bat species have “parts of their defense system” always active, according to Wang, which he calls “combat readiness.” permit; When a pathogen emerges, it encounters a host that has already equipped itself with powerful proteins that disrupt the virus’s life cycle, thus preventing the virus from getting out of control.

Transient bat infestations are devastating to humans

The idea here is that the viruses evolved themselves to adapt to the bats’ tricks, and became stronger as they attempted to infiltrate, reproduce, and then spread inside the bats’ fortified cells. According to Cara Brock, an environmental scientist who specializes in diseases, an attack on the scale of bats may be too much for humans to not have this level of protection, and it could help explain the harm caused to us by viruses that develop in bats. In short, an infection that goes unnoticed by a bat can cause great confusion in humans.

One of his ideas for dealing with this kind of variation in pathogen hospitality is to use drugs that slightly dampen our immune responses, Wang suggests. That is, to become a bit like a bat. The move could also reduce the risk of autoimmunity, he said, and delay aging or some types of chronic metabolic diseases. Notably, one of his experiments was the “bat-mouse,” which he and his team engineered to express a specific gene that suppresses inflammation in bats, and whose results were similar to influenza, SARS-CoV-2, and even arthritis.

* “The Atlantic Online”

– Tribune Media Services: “The human bat” could be the source of new treatments to fight diabetes and control infectious diseases.