In a groundbreaking discovery, researchers have found that parasites behind leprosy disease can reprogramme cells to increase the size of a liver.
The latest findings from a research team from the University of Edinburgh suggest the possibility of adapting this natural process from leprosy disease to renew ageing livers and increase health span which is the length of time living disease-free in humans.
It could help regrow damaged livers reducing the need for transplantation, which is currently the only cure for people with end-stage scarred liver.
The findings were published in Cell Reports Medicine.
Reprogramming the bacteria from leprosy disease
Previous studies have shown the regrowth of mouse livers by generating stem cells and progenitor cells, which is the step following the stem cell that can become any type of cell for a specific organ. An invasive technique was used in this process which often resulted in scarring and tumour growth.
These harmful side effects lead the Edinburgh team to discover the partial cellular reprogramming ability of the leprosy disease bacteria called Mycobacterium leprae.
They worked with the US Department of Health and Human Services in Baton Rouge, Louisiana, where they infected 57 armadillos – a natural host of leprosy disease bacteria – with the parasite and compared their livers with unaffected armadillos and those who were resistant to infection.
The teams found that the infected animals developed enlarged but healthy and unharmed livers with the same vital components, such as blood vessels, as the uninfected and resistant armadillos.
The regenerative ability of the liver
The team believe that the leprosy disease bacteria ‘hijacked’ the inherent regenerative ability of the liver to increase the organ’s size and, therefore, to provide it with more cells within which to increase.
Several indicators were found showing the main kinds of liver cells, known as hepatocytes, had reached a ‘rejuvenated’ state in the infected armadillos. The livers of the infected armadillos contained gene expression patterns similar to those seen in young animals and human fetal livers.
Genes related to metabolism, growth, and cell proliferation were activated and those linked with ageing were downregulated or suppressed. The scientists believe that the leprosy disease bacteria reprogrammed the liver cells, returning them to the earlier stage of progenitor cells, which became new hepatocytes and grow new liver tissues.
The team are hoping the discovery could lead to new developments for ageing and damaged livers in humans.
“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 ageing livers and to regenerate damaged tissues,” commented Professor Anura Rambukkana of the University of Edinburgh’s Centre for Regenerative Medicine.