Endogenous miR-21 and TIMP-1 Regulate Hepatic Injury and Fibrosis by Bile Duct Ligation in Vivo

Abstract TIMP metallopeptidase inhibitor 1 (TIMP-1) has been identified as a multifunctional molecule with divergent functions. It participates in wound healing and regeneration, cell morphology and survival, tumor metastasis, angiogenesis, and inflammatory responses. An imbalance of Matrix Metalloproteinase/TIMP regulation has been implicated in several inflammatory diseases. TIMP-1 could be considered an important regulator in the process of liver fibrosis and bile duct degeneration. Thus, we aimed to determine the role of TIMP-1 in a rat model of Common Bile Duct Ligation (CBDL). Male Sprague-Dawley rats were divided into several groups, including those with/ without CBDL surgery and those with/without amiodarone or simvastatin administration. Amiodarone/simvastatin treatment was given at a daily dose of 15 mg/kg and 18 mg/kg by means of intergalactic gavage, which began 7 days prior to CBDL induction. Two weeks after surgery, the animals in each group were sacrificed and hepatocyte degeneration severity was examined using histological morphologies. Large-scale array for secretory factors is intended for the purpose of finding key functional protein after CBDL. The hepatic level of miR-21 was determined through Taqman miRNA analysis. Furthermore, the TIMP-1 level in liver tissue was also visualized by histological stain. Liver injury and fibrosis were founded in CBDL rats based upon histopathological examination and serum biochemical analysis. Hepatic miR-21 and TIMP-1 were significantly up-regulated in CBDL rats, while being slightly rescued in response to amiodarone or simvastatin treatment. Up-regulation of miR-21 and TIMP-1 may result in the progression of hepatic cirrhosis after bile duct obstruction. Drug intervention for cirrhosis, like the use of statin, may function via similar mechanisms.