Studies on the mechanism of SIRT1/AMPK signaling pathway between hepatocytes and hepatic stellate cells / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To investigate the mechanism of SIRT1/AMPK signaling pathway between hepatocytes and hepatic stellate cells (HSCs). METHODS Normal human Chang liver cells and human hepatic stellate cell line, LX-2 cells were treated with SRT1720 (10 μmol·L-1) and AICAR (500 μmol·L-1) prior to ethanol (50 mmol·L-1) for 24 and 48 h. Cell viability was analyzed by methyl thiazolyl tetrazolium assay. SIRT1, AMPK and p-AMPK mRNA levels for 24 h and 48 h were analyzed by RT-PCR, SIRT1, AMPK and p-AMPK protein expressions in the supernatant at 24 and 48 h was detected by Western blot. RESULTS SRT1720 and AICAR effectively decreased LX-2 cell viabilities and exhibited scarcely little toxicity in human Chang liver cells. SRT1720 and AICAR attenuated collagen-I, α-smooth muscle actin (α-SMA) levels, activated liver kinase B-1 (LKB1) and AMPK phosphorylation in ethanol treated LX-2 cells. Meanwhile, SRT1720 and AICAR enhanced SIRT1 expression mediated by ethanol both in Chang liver cells and LX-2 cells. Furthermore, SRT1720 and AICAR suppressed the expression of sterol regulatory element-binding protein-1 (SREBP-1) to regulate fatty acid synthesis. CONCLUSION SIRT1 agonist and AMPK agonist blocked the crosstalk between hepatocytes and HSCs via SIRT1/AMPK signaling pathway to modulate hepatocytes accumulation of lipid and HSCs activation.