Posted on August 13, 2015 by MFeiock
UCSD NEWS RELEASE
Newly Discovered Cells Regenerate Liver Tissue Without Forming Tumors
Of all major organs, the liver has the highest capacity to regenerate — that’s why many liver diseases, including cirrhosis and hepatitis, can often be cured by transplanting a piece of liver from a healthy donor. The liver’s regenerative properties were previously credited to a population of adult stem cells known as oval cells. But recent studies concluded that oval cells don’t give rise to hepatocytes; instead, they develop into bile duct cells. These findings prompted researchers to begin looking elsewhere for the source of new hepatocytes in liver regeneration.
In this latest study, led by Michael Karin, PhD, Distinguished Professor of Pharmacology and Pathology, researchers traced the cells responsible for replenishing hepatocytes following chronic liver injury induced by exposure to carbon tetrachloride, a common environmental toxin. That’s when they found a unique population of hepatocytes located in one specific area of the liver, called the portal triad. These special hepatocytes, the researchers found, undergo extensive proliferation and replenish liver mass after chronic liver injuries. Since the cells are similar to normal hepatocytes, but express low levels of bile duct cell-specific genes, the researchers called them “hybrid hepatocytes.”... (CONTINUED)
This research was funded by the National Institutes of Health, including the Superfund Research Program at the National Institute of Environmental Health Sciences (grants CA118165, CA155120, P30 CA014195-38, F32CA136124, ES010337, HL053670, AI048034, DK078803 and DK068471), California Institute for Regenerative Medicine, Rotary Foundation, Uehara Memorial Foundation, German Research Foundation, Japan Society for the Promotion of Science, Japanese Society of Gastroenterology, Tokyo Society of Medical Sciences, Kanae Foundation for the Promotion of Medical Science, Frances C. Berger Foundation, Leona M. and Harry B. Helmsley Charitable Trust and JDRF.
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