Effects of fluctuant hyperglycemia on autophagy of endothelial cells

ObjectiveTo investigate the effect of fluctuant hyperglycemia on autophagy of endothelial cells and its possible mechanism.

MethodsHuman umbilical vein endothelial cells (HUVEC) were cultured in vitro for experiments with control group (5.5 mmol/L glucose) and intermittent high glucose group (5.5/28 mmol/L glucose). Intermittent high glucose simulating human blood glucose fluctuations was alternately cultured every 4 hours in the first 12 h and 5.5mmol/L for another 12 h.According to this cycle, the cells were cultured for 48 h in total.Cell viability was measured by CCK-8, indicators related oxidative stress were detected by microplate reader, and detection of gene related autophagy by real-time fluorescent quantitative PCR.

ResultsCompared with the control group, intermittent high glucose group reduced cell viability, decreased intracellular antioxidant enzyme activity, increased the expression of malondialdehyde (MDA) and 8-Hydroxydeoxyguanosine (8-OHdG) (P < 0.01), and increased the expression of Atg4 and Atg5 related autophagy(P < 0.001).

ConclusionFluctuant hyperglycemia may induce oxidative stress of HUVEC, thereby causing autophagy of HUVEC, ultimately to reduce cell viability.