Reversibility of Liver Fibrosis

Reversibility of liver fibrosis has been reported both experimentally and clinically, if the cause of liver damage is removed or adequately treated. We first reported the collagenase activity in the process of experimental liver fibrosis in 1974. The present review discusses the participation of matrix metalloproteinases (MMPs), especially MMP-1/MMP-13, in the spontaneous resolution of liver fibrosis, in association with tissue inhibitor of MMPs (TIMPs). A recent advance in molecular biology has revealed the important role of MMPs and TIMPs in the recovery from liver fibrosis and cirrhosis. In situ hybridization study showed that some stem/progenitor cells expressing MMP-13 mRNA may play an important role in the recovery from liver cirrhosis, and these cells were determined to be neural cells by us to be neural origin. Transfusion of stem cells derived from bone marrow will be applied to patients with liver cirrhosis in near future. Suitable conditions to make stem cells proliferate and differentiate for the expression of MMP-13 should be developed.