IGF-I induces senescence of hepatic stellate cells and limits fibrosis in a p53-dependent manner

• Published in: Scientific reports 2016-10, Vol.6 (1), p.34605-34605, Article 34605
• Main Authors: Nishizawa, Hitoshi, Iguchi, Genzo, Fukuoka, Hidenori, Takahashi, Michiko, Suda, Kentaro, Bando, Hironori, Matsumoto, Ryusaku, Yoshida, Kenichi, Odake, Yukiko, Ogawa, Wataru, Takahashi, Yutaka
• Format: Article
• Language: English
• Subjects: 13/1; 14/63; 38/90; 631/443/319/1642/2037; 631/80/509; 64/110; 64/60; 82/1; 82/29; Animal models; Animals; Cellular Senescence; Choline; Cirrhosis; Disease Models, Animal; Fibrosis; Gene Expression Regulation - drug effects; Hepatic Stellate Cells - metabolism; Hepatic Stellate Cells - pathology; Humanities and Social Sciences; Insulin-like growth factor I; Insulin-Like Growth Factor I - genetics; Insulin-Like Growth Factor I - metabolism; Liver; Liver cirrhosis; Liver Cirrhosis - chemically induced; Liver Cirrhosis - genetics; Liver Cirrhosis - metabolism; Liver Cirrhosis - pathology; Male; Methionine; Mice; Mice, Inbred ICR; Mitochondria; multidisciplinary; N-Nitrosodimethylamine; Non-alcoholic Fatty Liver Disease - chemically induced; Non-alcoholic Fatty Liver Disease - genetics; Non-alcoholic Fatty Liver Disease - metabolism; Non-alcoholic Fatty Liver Disease - pathology; Oxidative stress; p53 Protein; Rodents; Science; Senescence; Steatosis; Stellate cells; Tumor Suppressor Protein p53 - genetics; Tumor Suppressor Protein p53 - metabolism
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep34605

Hepatic fibrosis in nonalcoholic steatohepatitis (NASH) and cirrhosis determines patient prognosis; however, effective treatment for fibrosis has not been established. Oxidative stress and inflammation activate hepatic stellate cells (HSCs) and promote fibrosis. In contrast, cellular senescence inhibits HSCs’ activity and limits fibrosis. The aim of this study was to explore the effect of IGF-I on NASH and cirrhotic models and to clarify the underlying mechanisms. We demonstrate that IGF-I significantly ameliorated steatosis, inflammation, and fibrosis in a NASH model, methionine-choline-deficient diet-fed db/db mice and ameliorated fibrosis in cirrhotic model, dimethylnitrosamine-treated mice. As the underlying mechanisms, IGF-I improved oxidative stress and mitochondrial function in the liver. In addition, IGF-I receptor was strongly expressed in HSCs and IGF-I induced cellular senescence in HSCs in vitro and in vivo . Furthermore, in mice lacking the key senescence regulator p53, IGF-I did not induce cellular senescence in HSCs or show any effects on fibrosis. Taken together, these results indicate that IGF-I induces senescence of HSCs, inactivates these cells and limits fibrosis in a p53-dependent manner and that IGF-I may be applied to treat NASH and cirrhosis.