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.