Effect of high glucose toxicity on JNK pathway,cell viability and apoptosis in pancreatic ?-cell line INS-1 / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effect of high glucose toxicity on JNK pathway and cell function of INS-1 cells.METHODS: Cultured INS-1 cells with or without IGF-1 exposure,were treated with glucose at 3 concentrations (5.6 mmol/L,11.2 mmol/L and 33.3mmol/L),respectively. MTT was used to measure the cell viability. Apoptosis was determined by immuno-fluorescence and flow-cytometry analysis. The serine 270 phosphorylation of IRS and phosphorylation of JNK in INS-1 cells were detected in the presence or absence of SP600125 treatment.RESULTS: The cell viability decreased and apoptosis increased with elevated glucose concentrations. The percentage of apoptosis cells was 11.3% in 5.6 G group,12.7% in 11.2 G group and 28.2% in 33.3 G group. There was remarkable increase in apoptosis in 33.3 G group with a 2.49-fold increase to the cells in the basal 5.6 mmol/L glucose. High glucose activated the serine 270 phosphorylation of IRS correlates with JNK phosphorylation in INS-1 cells. Using Western blotting analysis,the levels of JNK phosphorylation were 3.33 fold increased and serine 270 phosphorylation of IRS was 1.17 fold increased in 33.3 G group compared to 11.2 G group (P