SIRT1 and Hepatic fibrosis: In liver tissue of rats with hepatic fibrosis, it has been observed that miR-34a and acetyl-p53 were up-regulated and SIRT1 was down-regulated; nevertheless, SIRT1 activator significantly reduced the levels of miR-34a and acetyl-p53, and inhibited fibrosis, which suggested that miR-34a/SIRT1/p53 signaling pathway was activated in fibrosis; in vitro, it was further confirmed that miR-34a/SIRT1/p53 signaling pathway was activated in epithelial cells to induce apoptosis, which activate hepatic stellate cells (HSCs) and accelerate the process of liver fibrosis (Tian et al., 2016).