Introduction:
Simvastatin (SIM) treatment has been found to be able to reduce the expression of miR-34a, and we found that interleukin-10 (IL-10) is a potential target gene of miR-34a by searching the online microRNA (miRNA) database. Furthermore, it has been shown that IL10 up-regulation could halt the progression of cirrhosis. The objective of this study was to explore the underlying mechanism of Simvastatin/miR-34a/IL-10 involved in HBV associated cirrhosis.

Material and methods:
Real-time PCR, western-blot analysis, immunohistochemistry, computational analysis, luciferase assay was carried out to explore the underlying mechanism of miR-34a involved in HBV associated cirrhosis.

Results:
SIM treatment dose-dependently decreased the levels of miR-34a while increasing the levels of IL-10 mRNA and protein. Levels of IL-10 mRNA and protein were remarkably decreased, while miR-34a mRNA level and active caspase-3 protein level was apparently increased in Cirrhosis group compared with sham group. Accordingly, SIM treatment obstructed the dysregulated miR-34a expression and IL-10 expression in cirrhosis animals. By performing computational analysis, we identified that a complementary binding site of miR-34a was located in IL-10 3’ untranslated region (3’UTR), and miR-34a reduced luciferase activity of wild-type IL-10 3’UTR.

Conclusions:
Our data also suggested that SIM may become a new therapeutic strategy for HBV-associated cirrhosis via targeting the miR-34a/IL-10 axis.