Mir-34a Is Upregulated during Liver Regeneration in Rats and Is Associated with the Suppression of Hepatocyte Proliferation

Background: MicroRNAs are a class of small regulatory RNAs that modulate a variety of biological processes, including cellular differentiation, apoptosis, metabolism and proliferation. This study aims to explore the effect of miR-34a in hepatocyte proliferation and its potential role in liver regeneration termination. Methodology/Principal Finding: MiR-34a was highly induced after partial hepatectomy. Overexpression of miR-34a in BRL3A cells could significantly inhibit cell proliferation and down-regulate the expression of inhibin bB (INHBB) and Met. In BRL3A cells, INHBB was identified as a direct target of miR-34a by luciferase reporter assay. More importantly, INHBB siRNA significantly repressed cell proliferation. A decrease of INHBB and Met was detected in regenerating liver. Conclusion/Significance: MiR-34a expression was upregulated during the late phase of liver regeneration. MiR-34amediated regulation of INHBB and Met may collectively contribute to the suppression of hepatocyte proliferation.