Silencing p53 inhibits interleukin 10-induced activated hepatic stellate cell senescence and fibrotic degradation in vivo

Activated hepatic stellate cells are reported to play a significant role in liver fibrogenesis. Beside the phenotype reversion and apoptosis of activated hepatic stellate cells, the senescence of activated hepatic stellate cells limits liver fibrosis. Our previous researches have demonstrated that interleukin-10 could promote hepatic stellate cells senescence via p53 signaling pathway in vitro. However, the relationship between expression of p53 and senescence of activated hepatic stellate cells induced by interleukin-10 in fibrotic liver is unclear. The purpose of present study was to explore whether p53 plays a crucial role in the senescence of activated hepatic stellate cells and degradation of collagen mediated by interleukin-10. Hepatic fibrosis animal model was induced by carbon tetrachloride through intraperitoneal injection and transfection of interleukin-10 gene to liver was performed by hydrodynamic-based transfer system. Depletions of p53 in vivo and in vitro were carried out by adenovirus-based short hairpin RNA against p53. Regression of fibrosis was assessed by liver biopsy and collagen staining. Cellular senescence in the liver was observed by senescence-associated beta-galactosidase (SA-β-Gal) staining. Immunohistochemistry, immunofluorescence double staining, and Western blot analysis were used to evaluate the senescent cell and senescence-related protein expression. Our data showed that interleukin-10 gene treatment could lighten hepatic fibrosis induced by carbon tetrachloride and induce the aging of activated hepatic stellate cells accompanied by up-regulating the expression of aging-related proteins. We further demonstrated that depletion of p53 could abrogate up-regulation of interleukin-10 on the expression of senescence-related protein in vivo and vitro. Moreover, p53 knockout in fibrotic mice could block not only the senescence of activated hepatic stellate cells, but also the degradation of fibrosis induced by interleukin-10 gene intervention. Taken together, our results suggested that interleukin-10 gene treatment could attenuate carbon tetrachloride-induced hepatic fibrosis by inducing senescence of activated hepatic stellate cells in vivo, and this induction was closely related to p53 signaling pathway. Impact statement This work further expanded the knowledge of the molecular mechanisms underlying IL-10 anti-fibrogenic effect by exploring the function of p53 in IL-10-induced activated HSCs senescence and fibrotic degradation in vivo. Our data showed that IL-10 gene intervention could lighten hepatic fibrosis induced by CCL4 and induce the senescence of activated HSCs accompanied by up-regulating the expression of senescence-related proteins. In addition, depletion of p53 could abrogate up-regulation of IL-10 on the expression of aging-related proteins in vivo and vitro. Moreover, p53 knockout in fibrotic mice could block the senescence of activated HSCs and the degradation of fibrosis induced by IL-10 gene treatment. In summary, our results suggested that IL-10 gene intervention could attenuate CCL4-induced hepatic fibrosis by inducing senescence of activated HSCs in vivo, and this induction was closely related to p53 signaling pathway. Our study sheds important light into the anti-fibrogenic therapy of IL-10.