EZH2-mediated H3K27me3 promotes autoimmune hepatitis progression by regulating macrophage polarization.

Autoimmune hepatitis (AIH) is a chronic progressive liver disease related to abnormal immune stimulation, leading to liver cirrhosis, liver cancer and liver failure. There is an urgent need to find novel biomarkers and potential drug targets for effective treatment of the disease. Although previous studies have shown that EZH2, as a histone methyltransferase, plays critical roles in tumor and autoimmune diseases, its role in autoimmune hepatitis remains largely unknown. In this study, we reported that the EZH2 and H3K27me3 expression level was significantly upregulated in liver tissues during the progression of AIH. High expression of EZH2 enhanced autoimmune hepatitis, immune response and liver fibrosis through H3K27me3. EZH2 inhibition induced the phenotype of hepatic macrophages to switch from M1 to M2 in the development of AIH. These findings indicated that EZH2-mediated H3K27me3 promoted autoimmune hepatitis by regulating the polarization of hepatic macrophages. EZH2 may be a promising therapeutic target for the prevention or treatment of autoimmune hepatitis.