Effect of sitagliptin on lipopolysaccharide-induced changes in the mass and function of islet β cells / 中华内分泌代谢杂志

ABSTRACT

Objective To investigate the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor on lipopolysaccharide (LPS)-induced changes in the mass and function of pancreatic β-cells.Methods RINm cells were cultured and treated with LPS alone or combined with different concentrations of sitagliptin for 24 h.The proliferation of RINm cells was detected by CCK-8 assay.Apoptotic rate was determined by Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide flow cytometry.Insulin secretion was measured by enzyme-linked immunosorbent assay.The expression of IL-6 mRNA was displayed by RT-PCR.Results LPS significantly stimulated the proliferation of RINm cells (0.89 ± 0.04 vs 1.14 ± 0.08,P＜0.01),while LPS+sitagliptin showed no significant difference compared with LPS group.The cell apoptotic rate in LPS + 10-1 mmol/L sitagliptin group was significantly lower than that in LPS group.There were no significant differences in basal insulin secretion among all groups,but after the high/low glucose stimulation,LPS increased insulin secretion as compared with the control.The IL-6 mRNA expression in LPS+sitagliptin group was significantly lower than that in LPS group (0.77 ± 0.33 vs 1.30 ± 0.41,P =0.006).Conclusions DPP-4 inhibitor has no influence on LPS-induced proliferation of pancreatic β-cell,but it can inhibit LPS-induced apoptosis and insulin secretion,and IL-6 may be involved in the process.