高糖致心肌微血管内皮细胞损伤时SIRT1与STAT3乙酰化的关系

Relationship between SIRT1 and STAT3 acetylation during high glucose-induced cardiac microvascular endothelial cell injury

目的评价高糖致心肌微血管内皮细胞损伤时沉默信息调节因子1(SIRT1)与信号转导子及转录激活子3(STAT3)乙酰化的关系。方法培养SD大鼠心肌微血管内皮细胞,取正常对数期生长的细胞,采用随机数字表法分为3组(n=24):对照组(C组)、高糖组(HG组)和高糖+SIRT1激动剂SRT1720组(HG+SRT组)。心肌微血管内皮细胞以每孔2×10^(5)个/ml的密度接种于6孔板或96孔板中培养,当细胞密度达50%时,将HG组和HG+SRT组更换为含1%胎牛血清和1%双抗的葡萄糖浓度为33 mmol/L的高糖培养基,同时HG+SRT组加入20μmol/L SRT1720,置于37℃、5%CO2培养箱中孵育24 h。采用CCK-8法检测细胞活力,测定细胞SOD活性,ELISA法检测上清液LDH、IL-6和TNF-β水平,Western blot法检测SIRT1、乙酰化STAT3(ac-STAT3)及磷酸化STAT3(p-STAT3)的表达水平。结果与C组比较,HG组和HG+SRT组细胞活力和SOD活性降低,上清液LDH、IL-6和TNF-β水平升高,细胞SIRT1表达下调,ac-STAT3和p-STAT3表达上调(P<0.05);与HG组比较,HG+SRT组细胞活力和SOD活性升高,上清液LDH、IL-6和TNF-β水平降低,细胞SIRT1表达上调,ac-STAT3和p-STAT3表达下调(P<0.05)。结论SIRT1可通过促进STAT3脱乙酰化,减轻高糖致心肌微血管内皮细胞损伤。

Objective To evaluate the relationship between silence information regulator 1(SIRT1)and signal transducers and activators of transcription 3(STAT3)acetylation during high glucose-induced cardiac microvascular endothelial cell injury.Methods Cardiac microvascular endothelial cells of Sprague-Dawley rats were cultured.The cells at the logarithmic growth phase were selected and divided into 3 groups(n=24 each)using a random number table method:control group(C group),high glucose group(HG group)and high glucose+SIRT1 agonist SRT1720 group(HG+SRT group).The cardiac microvascular endothelial cells were seeded in a 6-or 96-well cell culture plate at a density of 2×10^(5) cells/ml.When the cell density reached 50%,the culture medium was then replaced with high-glucose(glucose 33 mmol/L)DMEM culture medium containing with 10%fetal bovine serum and 1%double antibody in HG and HG+SRT groups.In group HG+SRT,20μmol/L SRT1720 was added simultaneously,and the cells were cultured at 37℃in an incubator with 5%CO2 for 24 h.The cell viability was determined by CCK-8 assay,the activity of superoxide dismutase(SOD)was detected using a spectrophotometer,the levels of lactic dehydrogenase(LDH),interleukin-6(IL-6)and tumor necrosis factor-β(TNF-β)in the supernatant were detected by enzyme-linked immunosorbent assay,and the expression of SIRT1,acetylated STAT3(ac-STAT3)and phosphorylated STAT3(p-STAT3)was determined by Western blot.Results Compared with C group,the cell viability and SOD activity were significantly decreased,levels of LDH,IL-6 and TNF-βin the supernatant were increased,expression of SIRT1 was down-regulated,and expression of ac-STAT3 and p-STAT3 was up-regulated in group HG and group HG+SRT(P<0.05).Compared with group HG,the cell viability and SOD activity were significantly increased,levels of LDH,IL-6 and TNF-βin the supernatant were decreased,expression of SIRT1 was up-regulated,and expression of ac-STAT3 and p-STAT3 was down-regulated in group HG+SRT(P<0.05).Conclusion SIRT1 can alleviate high glucose-induced cardiac microvascular endothelial cell injury by promoting STAT3 deacetylation.