Mesenchymal stem cells attenuate sepsis-induced liver injury via inhibiting M1 polarization of Kupffer cells

Sepsis is a leading cause of death in intensive care units that can result in acute hepatic damage. Animal experiments and clinical trials have shown that mesenchymal stem cell (MSC) therapy has some beneficial in several liver diseases. However, the protective effects of MSC therapy on sepsis-induced hepatic damage and associated mechanisms are not completely understood. The aim of the present study was to investigate the effects of MSCs on sepsis-induced liver injury and underlying mechanisms. A rat model of sepsis-induced liver injury was established by cecal ligation and puncture, and serum alanine aminotransferase and aspartate transaminase activities as well as liver histological changes were measured. Inflammatory cytokines, Kupffer cell M1 phenotype markers, and associated signal molecules were also determined in septic rats and in lipopolysaccharide (LPS)-treated Kupffer cells. Our results showed that injection of MSCs attenuated sepsis-induced liver injury. Treatment with MSCs inhibited activation of Kupffer cells towards M1 phenotype, attenuated TNF-α and IL-6 expression, and promoted IL-4 and IL-10 expression in septic rats and LPS-treated Kupffer cells. Furthermore, MSCs also inhibited the nuclear translocation of nuclear factor-kappa B in LPS-challenged Kupffer cells and the liver of septic rats. These results indicated that MSCs attenuated sepsis-induced liver injury through suppressing M1 polarization of Kupffer cells.