Liver Scarring Mechanism Identified In Mice
The human liver may be our most undervalued organ.
Not only does it have lizard-like regenerative powers, its eight connected lobes work round the clock to detoxify us of our vices – be they a slab of fatty steak or a flagon of beer.
When we aren’t being bad, and even when we are, the liver also helps us digest our food, store energy and vitamins (it can hold several years’ worth of B-12), and clear our blood of residues from taking medications. It even plays a role in maintaining our hormonal balance and keeping our bones strong.
It does all of this if that meaty three-pound organ under the right side of our ribcage is working properly. If the liver becomes diseased, many vital bodily processes can go awry.
Regardless of the type of assault or insult, the liver almost always shows signs of abuse by forming fibrous scar tissue, which can further impair the liver’s ability to function, with profound health consequences.
Reporting in the current issue of Proceedings of the National Academy of Sciences, researchers at the University of California, San Diego School of Medicine have described a fundamental mechanism underlying the progression of cholestatic liver fibrosis, which is caused by the impairment of bile formation or bile flow not by lifestyle choices, like heavy drinking.
“Our study puts into perspective many previously contradictory studies, and provides a general approach to understanding the distinct mechanisms which lead to liver scaring and fibrosis,” said senior author Tatiana Kisseleva, MD, PhD and an assistant professor in the Department of Surgery. Fibrosis refers to progressive liver scarring, occurring in most types of chronic liver disease.
In the study, researchers identified a type of cell in the livers of mice (portal fibroblasts) that respond to bile-related liver injuries. When these cells become activated and proliferate, they secrete fibrous scar tissue.
Though the study was conducted in mice, preventing the activation of these cells in human livers could help prevent liver scarring in people with cholestatic liver disease.
Toward this effort, the scientists have now identified novel markers of activated portal fibroblasts that could be used to evaluate the source of liver injury in patients.