PTPN14 aggravates inflammation through promoting proteasomal degradation of SOCS7 in acute liver failure

Abstract

Acute liver failure (ALF) is a rare but life-threatening systemic disorder. The innate immune regulation has an important role in this process; however, the specific mechanisms are not completely clear. Using the LPS + D-GalN-induced ALF mouse model, we found that the survival rate of PTPN14-deficient mice was higher than that of the control group, while the release of inflammatory factors was significantly lower. We further showed that PTPN14 interacted with SOCS7, and promoted the degradation of SOCS7 through ubiquitination at K11 and K48, thereby reducing the protein level of SOCS7 and weakening the inhibitory effects on inflammatory factors. More importantly, SOCS7 blocked the NF-κB signaling pathway by preventing the activity of the IKK complex, and then reduced the expression of downstream inflammatory factors. In this study, we firstly reported the inhibitory effect of SOCS7 on the NF-κB pathway in the ALF mouse model and elucidated the mechanism of PTPN14–SOCS7–NF-κB axis in the regulation of inflammation. These results provide new insights into the clinical treatment of ALF.