Lepra Bacillus helps regenerate the liver

Leprosy-causing bacteria may help regenerate a healthy liver, Writing Scottish Scholars in the journal Medicine Cell Reports. They discovered that armadillos with leprosy had larger livers than armadillos without leprosy, without any scarring or tumor growth in those livers, for example. But before leprosy bacteria can regenerate human livers, a lot of additional research is needed.

Leprosy is an infectious disease that can have severe consequences for humans. If left untreated, the disease can cause serious deformities of the face and limbs in a proportion of patients and can also affect the nerves. The culprit is bacteria leprae. Other animals are also susceptible, including the nine-banded armadillo Dasypus novemcinctus From South and Central America. Armadillos also develop skin and nerve disorders after being injured.

The liver is most suitable for the regeneration of all human organs. This makes organ donation relatively easy; A donor donates part of his liver, after which the remaining part grows into a full-fledged organ within a few weeks.

The bad news, however, is that this regeneration does not occur naturally in people with liver disease: internal scar tissue (as in cirrhosis) or tumor growth often develops. And if the liver has to repair itself too often, eventually the process stops and there is no other option than a transplant.

For this reason, the Scottish researchers are particularly interested in the enlarged liver in the injured armadillo, whose liver is four times its normal weight (290 instead of 70 grams) and is functioning healthily. Regeneration biologist Anura Rambukkana, who is one of the authors, discovered this phenomenon when he saw in 2013 how leprosy bacteria were able to ‘hijack’ the plasticity and regenerative properties of so-called Schwann cells. These cells are located around neurons, but are passed through them leprae They are partially reprogrammed to behave like stem cells. Stem cells are the ones that can grow into organs. This research was performed in Petri dishes, using cells taken from mice.

“The discovery sometimes kept me awake in the years that followed,” says Rambukkana — who once began his research on leprosy bacteria while he was a student in Amsterdam — by email. And one night I thought: In Louisiana, leprosy bacteria have been cultured in armadillo livers for decades for research purposes. Could there be something wrong with those livers? So I called a friend who researched there and casually asked him if he had noticed anything unusual about armadillos. Then he started talking about those enlarged livers of his own! That reinforced my suspicions that we might also be seeing the ‘biological chemistry’ we saw in petri dishes in live animals.”

Thus, Rambukkana and colleagues initiated the current study. To do this, they hit 45 armored personnel carriers and used 12 as a control group. Under the influence of leprosy bacteria, hepatocytes and own liver cells also began to act as a kind of stem cells. This caused the affected armadillo’s liver to swell, but retain all vital functions. In addition, genes related to aging were repressed, while genes related to growth were activated.

Exactly what beneficial applications this discovery might have for medicine still needs further research. “If we can figure out how to reprogram bacteria and regenerate the liver, we might be able to apply this method to humans as well,” Rambukkana says. “But we’re not there yet.”