Effects of heat shock protein 27 phosphorylation in human umbilical vein endothelial cells apoptosis induced by high glucose

Objective To investigate the role of heat shock protein-27(HSP-27) phosphorylation in human umbilical vein endothelial cells(HUVEC) apoptosis induced by high glucose.Methods HUVEC were isolated from umbilical cords of healthy caesarean women.Cells at passages 2-3 were used in this study.①To detect the effect of high glucose on activity of HSP-27 in HUVEC:cells were divided into normal group and high glucose group.The protein in normal group cells was extracted without any interventions.And the protein in high glucose group was extracted after cells were incubated by high glucose(30.5 mmol/L) for 24 h,48 h and 72 h respectively.②To detect the effect of quercetin on activity of HSP-27 induced by high glucose in HUVEC:cells were divided into three groups:normal group,high glucose groups,quercetin plus high glucose groups.Normal group received no interventions,high glucose group cells were treated with high glucose(30.5 mmol/L),and quercetin plus high glucose group cells were pretreated with quercetin(10 μmol/L) for 1 h before high glucose was added.Cellular proteins were obtained after incubation for 48 h.HSP-27 activity was evaluated by Western blotting with specific phospho-HSP27 antibody in the two experimental programs.Apoptosis of HUVEC was analyzed by Annexin V-FITC/PI Apoptosis Detection Kit and flow cytometry in program ②.Results High glucose induced HUVEC HSP-27 phosphorylation in a time-dependent manner.Compared with the control group,HSP-27 phosphorylation increased 100%(P0.05),182.5%(P0.01) and 117%(P0.05) respectively.after incubation with 30.5 mmol/L high glucose for 24,48 and 72 h.In comparison with high glucose group,HSP-27 phosphorylation induced by high glucose was inhibited 52.6% and apoptosis was increased 37.6% after exposure to the selective HSP-27 blocker quercetin(10 μmol/L) for 48 h(allP0.01).Conclusions HSP-27 phosphorylation may play a key role in HUVEC apoptosis induced by high glucose.