Loss of steroid receptor co-activator-3 attenuates carbon tetrachloride-induced murine hepatic injury and fibrosis

Abstract

Hepatic fibrosis, a disease characterized by altered accumulation of extracellular matrix, can cause cirrhosis and liver failure. There is growing interest in the impact of co-activators on hepatic fibrogenesis. Here, we provided genetic evidence that mice lacking steroid receptor co-activator-3 (SRC-3) were protected against carbon tetrachloride (CCl 4)-induced acute liver necrosis and chronic hepatic fibrosis. After acute CCl 4 treatment, SRC-3 / mice showed attenuated profibrotic response and hepatocyte apoptosis, whereas hepatocyte proliferation was elevated in SRC-3 / mice versus SRC-3 / mice. Similarly, chronically CCl 4 -treated SRC-3 / mice showed significant weakening of inflammatory infiltrates, hepatic stellate cell activation and collagen accumulation in the liver compared with SRC-3 / mice. Further investigation revealed that TGFΒ1/Smad signaling pathway was impaired in the absence of SRC-3. Moreover, the expression levels of SRC-3, as assessed in human tissue microarray of liver diseases, correlated positively with degrees of fibrosis. These data revealed that SRC-3 / mice were resistant to CCl 4 -induced acute and chronic hepatic damage and TGFΒ1/Smad signaling was suppressed in the lack of SRC-3. Our results established an essential involvement of SRC-3 in liver fibrogenesis, which might provide new clues to the future treatment of hepatic fibrosis. © 2009 USCAP, Inc All rights reserved.