摘要
Interleukin(IL)-22,a member of the IL-10 cytokine family,plays critical roles in tissue repair and host defense.IL-22 binds to its hetereodimeric receptor(R)composed of IL-22R1 and IL-10R2 and activates downstream signaling,including Signal transducer and activator of transcription 3(STAT3)pathways.IL-22 promotes the expression of survival genes in a STAT3-dependent manner.IL-22R1 expression is restricted mainly in epithelial cells while IL-10R2 is ubiquitously expressed in almost all cell types.In the liver,IL-22R1 is expressed in hepatocytes,liver progenitor cells,hepatic stellate cells and liver cancer cells.IL-22 protects the liver in various liver damage models and promotes liver regeneration after liver injury.IL-22 also helps to resolve liver fibrosis by inducing hepatic stellate cell senescence.IL-22 is considered a pro-inflammatory cytokine in viral hepatitis although it does not directly act on immune cells.IL-22 is reported to be involved in the development of liver cancer and in regulating energy metabolism.Studies on IL-22 in liver inflammation,injury and repair will provide valuable information to clarify IL-22 as a potential candidate for treating liver injury and fibrosis.
基金
This work was in supported by the National Natural Science Foundation of China(grant number:81100311,81470879/H0318 to S.Yin)and intramural program of USA National Institute on Alcohol Abuse and Alcoholism(NIAAA),National Institutes of Health(NIH).