Abstract:

BACKGROUND: Under physiological conditions, bile acids play an important role in the digestion and absorption of lipids and cholesterol metabolism, and the bile acid overload can lead to liver cell apoptosis and necrosis. However, studies of the effect of the low-concentration bile acids on liver cell proliferation are still few.
OBJECTIVE: To investigate the effect of the low-concentration cholic acid (CA) on rat liver cell proliferation and JNK, p38-MAPK protein expression.
METHODS: Rat hepatocytes were cultured in primary culture for 48 hours, then they were incubated in medium containing 0, 10, 20, 40, 80 μmol/L CA for 12 hours. The cell survival rate was determined by MTT assay. The cell cycles were detected by flow cytometry, and the relative percentage of S phase was calculated. The expression of JNK and p38-MAPK protein was detected by western blotting.
RESULTS AND CONCLUSION: There was no significant difference in survival rate below the concentration of 40 μmol/L CA; however, the relative percentage of S phase and JNK protein expression were significantly increased by 40 μmol/L CA (P < 0.05, P < 0.01). 80 μmol/L CA significantly decreased survival rate, relative percentage of S phase, and JNK expression (P < 0.01) but significantly increased p38-MAPK protein expression (P < 0.01). Therefore, low-concentrations CA could promote liver cell DNA synthesis, which might be caused by an increase of the JNK protein expression.