去天门冬氨酸血管紧张素Ⅰ减轻大鼠心肌微血管内皮细胞缺血/再灌注损伤

Protective effects of des-aspartate-angiotensin-Ⅰ against cardiac microvascular endothelial cell injury induced by ischemia/reperfusion

目的探讨去天门冬氨酸血管紧张素Ⅰ(DAA-Ⅰ)对大鼠心肌微血管内皮细胞(CMECs)缺血/再灌注损伤的影响。方法分离培养大鼠CMECs,建立模拟缺血/再灌注模型,完全随机分组,分为对照组、模拟缺血/再灌注组(SI/R组)、模拟缺血/再灌注+DAA-Ⅰ(2.5、3.75、5.0μmol/L)组。MTT检测细胞增殖能力,细胞划痕实验检测细胞迁移能力,TUNEL法检测细胞凋亡,采用Western blot检测GRP78/Bip、CHOP/GADD153、pro-caspase-12、cleaved-caspase-12蛋白的表达。结果与对照组相比较,SI/R组CMECs增殖能力明显降低(P<0.01),凋亡率显著上升(24.85%±0.67%比3.55%±0.11%,P<0.01)。与SI/R组相比,SI/R+DAA-Ⅰ组细胞增殖能力明显升高(P<0.01)并呈剂量依赖性,细胞迁移率上升(P<0.01)并呈剂量依赖性,凋亡率明显下降(15.18%±0.40%比24.85%±0.67%,P<0.01)并呈剂量依赖性。与对照组相比较,SI/R组和SI/R+DAA-Ⅰ组的GRP78、CHOP/GADD153、cleaved-caspase-12表达明显上升(均为P<0.01)。与SI/R组相比,SI/R+DAA-Ⅰ组的GRP78、CHOP/GADD153、cleaved-caspase-12表达明显降低(均为P<0.01)。结论 DAA-Ⅰ可显著抑制缺血/再灌注损伤诱导的CMECs凋亡,促进CMECs存活,改善细胞功能,其保护作用可能与下调ERS相关蛋白的表达有关。

Objective To explore the protective effect of DAA-I against ischemia/repeffusion injury of cardiac microvascular endothelial cell. Methods CMECs isolated from the hearts of aduh rats were exposed to hypoxia （94% N2, 5% CO2, 1% O2 ） and ischemia buffer for 2 h followed by 4 h reoxygenation （95% air, 5% CO2 ）. The cell viability of CMECs was measured by MTY assay and migration ability of CMECs was detected by cell scratch wound assay. The apoptosis of CMECs was detected by TUNEL method. The expression of ERS related apoptotic proteins were analyzed by western blot. Results Both cell viability and migration ability were impaired after SI/R （P 〈 0. 01 vs. control）, and the apoptosis index was increased compared with control group （24.85% ±0.67% vs. 3.55% ±0.11% , P 〈0. 01 ）. While administration of DAA-I during reperfusion dramatically attenuate the dysfunction of CMECs and down-regulate the expression of ERS related proteins. Conclusions DAA-I has protective effect of CMECs against ischemia/reperfusion injury through down-regulating of ERS related proteins expression.