Cure for liver disease may be in bacteria that causes leprosy

EDINBURGH, Scotland — Leprosy may hold the key to curing liver disease — ending the need for organ transplants, according to new research.

A team at the University Edinburgh say the ancient infection harbors a bug that can actually program cells to regenerate the vital organ, increasing its size without causing damage, scarring, or tumors. Experiments on armadillos suggest that scientists can adapt it to combat the growing rates of liver problems. Liver disease is generally triggered by obesity, with one in four people dealing with the disorder — many don’t even know they have it.

It initially causes no symptoms, making it hard to spot until it is too late. Ultimately, this leads to liver failure, leaving patients in need of a transplant. The armored mammal carries Mycobacterium leprae, which causes leprosy — also known as Hansen’s disease.

“If we can identify how bacteria grow the liver as a functional organ without causing adverse effects in living animals, we may be able to translate that knowledge to develop safer therapeutic interventions to rejuvenate aging livers and to regenerate damaged tissues,” says lead author Professor Anura Rambukkana from the University of Edinburgh’s Center for Regenerative Medicine in a media release.

Leprosy has had a terrifying reputation for centuries

Leprosy has haunted humanity for thousands of years, leaving victims scarred, deformed, and social outcasts. Lepers have been near-universally reviled, locked in colonies, forbidden from marrying, and expelled from cities. Their appearance in literature often paints them as morally unfit and brimming with ill-will.

However, evidence is growing that Mycobacterium leprae can reinvigorate aging livers and increase the disease-free window of human lifespans. It would help address the chronic donor organ shortage. Currently, the only option for people with end-stage scarred livers is a transplant.

Previous attempts at boosting mouse livers with an invasive technique using stem cells capable of being any type of tissue resulted in scarring and tumors. Prof. Rambukkana and colleagues overcame the harmful side-effects by turning to Mycobacterium leprae.

They discovered it performing “biological alchemy,” turning nerves into stem cells and muscle in a natural host’s body. The team, including colleagues at the U.S. Department of Health and Human Services, infected 57 armadillos with the parasite.

They compared their livers with those of uninfected armadillos and those that were found to be resistant to infection. Infected animals developed enlarged yet healthy and unharmed livers with the same vital components such as blood vessels, bile ducts, and functional units called lobules.

The bacteria “hijacked” the inherent regenerative ability of the liver to increase the organ’s size and provide it with more cells within which to increase. The team also found the main liver cells, called hepatocytes, reached a “rejuvenated” state.

The infected armadillos’ livers also contained gene expression patterns, the blueprint for building a cell, similar to those in younger animals and human fetal livers. Genes related to metabolism, growth, and cell proliferation activated and those linked with aging were downregulated — or suppressed.

Scientists believe the bacteria reprogramed the liver cells, returning them to the earlier stage of progenitor cells, which in turn became new hepatocytes and liver tissue. The findings in the journal Cell Reports Medicine have the potential to help develop interventions for aging and damaged livers in humans, Prof. Rambukkana adds.

Is the best treatment for liver disease a healthy diet?

Liver diseases claim two million lives worldwide each year. It often goes undiagnosed and can eventually lead to cardiovascular disease. Known as non-alcoholic fatty liver disease (NAFLD), the condition is the result of vast amounts of fat gathering around the organ.

The life-threatening condition sometimes results in inflammation, scarring, and even organ failure. Prevalence could be even higher given the challenges in diagnosis. Unhealthy diets of junk food and sugary beverages are fueling the epidemic.

The condition increases the risk of serious liver damage, including cirrhosis. Lifestyle changes are the cornerstone of treatment. These include cutting down on ready-to-eat meals, burgers, processed meats, pizzas, and pastries, and eating more fiber-rich vegetables and whole grains. Health experts also recommend a Mediterranean-style diet and avoiding alcohol.

South West News Service writer Mark Waghorn contributed to this report.

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