A synthetic form of vitamin D may provide a new therapy for liver fibrosis in humans, according to a new study published in the journal Cell.
Liver fibrosis is the scarring process that results from injury to the liver. Main causes of liver diseases leading to fibrosis are chronic hepatitis virus infection, excessive continuous alcohol consumption, and nonalcoholic steatohepatitis (NASH).
Researchers at the Salk Institute for Biological Studies found that a vitamin D analog, calcipotriol (currently FDA approved for the treatment of psoriasis), inhibits the fibrotic response in mouse liver cells.
The Salk scientists examined a particular “stellate” liver cell that plays a central role in liver damage. When necessary, stellate cells produce fibrotic proteins in an attempt to heal an injury. However, under chronic stress, fibrosis increases, ultimately leading to loss of liver function and an increased risk of liver cancer.
Past research has shown that vitamin D plays a role in liver function, but “it was our discovery of high levels of vitamin D receptor (VDR) in the stellate cell that led us to consider it as a possible off switch for liver fibrosis,” says lead author Ning Ding.
Researchers are intrigued because current therapies for the treatment of liver disease symptoms don’t inhibit fibrosis from progressing. This new information may also be helpful when treating other diseases with fibrotic symptoms, including diseases of the lungs, pancreas, and kidney.
Human clinical trials for the treatment of liver fibrosis with vitamin D analogues are being planned. It’ll likely be years until these trials show if there is any benefit. Currently, we don’t yet know if vitamin D analogues are helpful for people with liver fibrosis.