氯沙坦通过JAK2/STAT3信号通路在晚期糖基化终产物诱导心肌微血管内皮细胞损伤中的保护机制研究

Protective mechanism of losartan in the injury of myocardial microvascular endothelial cells induced by advanced glycation end products via JAK2/STAT3 signaling pathway

目的观察氯沙坦对大鼠心肌微血管内皮细胞的作用,以及对Janus蛋白酪氨酸蛋白激酶2/信号转导子和转录激活子3(JAK2/STAT3)信号通路的影响,探究氯沙坦对糖尿病的保护机制。方法将大鼠分成空白对照组、晚期糖基化终末产物(AGEs)组、AGEs加氯沙坦治疗组以及氯沙坦治疗组,进行晚期糖基化终产物和氯沙坦的干预。采用MTT法和TUNEL法检测大鼠心肌微血管内皮细胞的活力和凋亡率;采用Western blot和RT-PCR法对JAK2/STAT3信号通路中的相关蛋白表达水平进行检测;ELISA检测白细胞介素-6(IL-6)、肿瘤坏死因子-β(TNF-β)的水平。结果与空白对照组相比,AGEs组的大鼠心肌微血管内皮细胞的活力明显减弱、凋亡率上升,在JAK2/STAT3信号通路中相关蛋白表达和相关炎症因子IL-6、TNF-β的表达也明显升高(P<0.05)。AGEs加氯沙坦治疗组与AGEs组相比,细胞活力有所提升,凋亡率下降,JAK2/STAT3信号通路中相关蛋白表达和相关炎症因子IL-6、TNF-β的表达也有所下降(P<0.05)。氯沙坦治疗组的相关蛋白表达情况和炎性介质与空白对照组相比,差异无统计学意义(P>0.05)。结论氯沙坦可以通过JAK2/STAT3信号通路来对晚期糖基化终产物进行有效抑制,从而缓解其对心肌微血管内皮细胞的损伤,起到保护作用。

Objective To observe the effects of losartan on rat myocardial microvascular endothelial cells and Janus protein tyrosine protein kinase 2/signal transducer and transcriptional activator 3(JAK2/STAT3) signaling pathway, and explore protective mechanism of losartan on diabetes. Methods Rats were divided into a blank control group,(advanced glycation end products) AGEs group, AGEs plus losartan treatment group, and losartan treatment group for advanced glycation end products and losartan intervention. The activity and apoptosis rate of myocardial microvascular endothelial cells in rats were detected by MTT assay and TUNEL assay. The expression levels of related proteins in JAK2/STAT3 signaling pathway were detected by Western blot and RT-PCR. The levels of IL-6 and tumor necrosis factor-β(TNF-β) were detected by ELISA. Results Compared with the blank control group, the viability of myocardial microvascular endothelial cells in the AGEs group was significantly weakened and the apoptotic rate was increased. The expression of related proteins and the expression of related inflammatory factors IL-6 and TNF-β in the JAK2/STAT3 signaling pathway were also significantly elevated(P<0.05). Compared with the AGEs group, the AGEs plus losartan treatment group showed an increase in cell viability and a decrease in apoptotic rate. The expression of related proteins in the JAK2/STAT3 signaling pathway and the expression of related inflammatory factors IL-6 and TNF-β also decreased(P<0.05). There was no significant difference in the expression of related proteins and inflammatory mediators in the losartan group compared with the blank control group(P>0.05). Conclusion Losartan can effectively inhibit the advanced glycation end products through the JAK2/STAT3 signaling pathway, thereby alleviating the damage to myocardial microvascular endothelial cells and protecting them.