卡格列净改善自发性高血压大鼠主动脉重构的作用及其机制

Effects and mechanisms of Canagliflozin in mitigating aortic remodeling in spontaneously hypertensive rats

目的:探索卡格列净通过调控血管平滑肌细胞(VSMCs)增殖迁移及肾素-血管紧张素-醛固酮系统(RAAS)/转化生长因子β1(TGF-β1)信号通路,改善自发性高血压大鼠(SHR)胸主动脉重构。方法:将大鼠分为正常血压大鼠对照组(WKY组)、SHR组和SHR+卡格列净组。尾袖血压计监测大鼠尾动脉血压,H-E染色评估胸主动脉血管壁中膜厚度及中膜厚度/管腔直径比值,Masson染色检测血管壁纤维化程度。体外分离培养WKY和SHR胸主动脉VSMCs,细胞分为WKY组、WKY+卡格列净组、SHR组和SHR+卡格列净组。CCK-8检测细胞增殖,划痕实验检测细胞迁移,RT-qPCR和免疫印迹检测α-平滑肌肌动蛋白(α-SMA)、分泌型磷酸蛋白1(SPP1)、I型胶原蛋白(Col1a)、Ⅲ型胶原蛋白(Col3a)、血管紧张素原(AGT)、血管紧张素Ⅱ受体1(AGTR1)、TGF-β1 mRNA与蛋白表达。结果:给予卡格列净灌胃8周后,与SHR组相比,SHR+卡格列净组大鼠尾动脉血压、胸主动脉中膜厚度、中膜厚度/管腔直径比值、胶原蛋白沉积程度降低。SHR组VSMCs增殖、迁移能力较WKY组明显增强,α-SMA表达降低,SPP1、Col1a、Col3a、AGT、AGTR1、TGF-β1表达增高;SHR+卡格列净组较SHR组VSMCs的增殖与迁移能力明显减弱,α-SMA表达升高,SPP1、Col1a、Col3a、AGT、AGTR1、TGF-β1表达降低。结论:卡格列净可能通过抑制RAAS/TGF-β1信号通路,从而抑制高血压VSMCs增殖、迁移,改善自发性高血压大鼠主动脉血管重构。

Objective:To explore the effect of Canagliflozin on thoracic aorta remodeling in spontaneous hypertension rats(SHR)by regulating vascular smooth muscle cell proliferation,migration,and the reninangiotensin-aldosterone system(RAAS)/transforming growth factorβ1(TGF-β1)signaling pathway.Methods:The rats were divided into normal blood pressure control group(WKY group),SHR group,and SHR+Canagliflozin group.Tail-cuff sphygmomanometer was used to monitor the rats tail artery blood pressure(BP).H-E staining was used to evaluate the media thickness of thoracic aortic wall and the ratio of media thickness to lumen diameter.Masson staining was used to detect the degree of vascular wall fibrosis.Vascular smooth muscle cells(VSMCs)were isolated and cultured from thoracic aorta of WKY and SHR.Cells were divided into WKY group,WKY+Canagliflozin group,SHR group,and SHR+Canagliflozin group.Scratch assay was conducted to evaluate cell migration,while CCK-8 assay was performed to assess cell proliferation.The expressions of alpha-smooth muscle actin(α-SMA),secreted phosphoprotein 1(SPP1),collagen typeⅠalpha(Col1a),collagen typeⅢalpha(Col3a),angiotensinogen(AGT),angiotensinⅡreceptor 1(AGTR1)and TGF-β1 were detected by real-time quantitative polymerase chain reaction and Western blotting.Results:After eight weeks of canagliflozin administration,compared with the SHR group,the blood pressure,thoracic aortic media thickness,media thickness/lumen diameter ratio,and collagen deposition degree in the SHR+Canagliflozin group were decreased.The proliferation and migration ability of VSMCs in SHR group was significantly enhanced compared with that in WKY group,the expression ofα-SMA was decreased,and the expression of SPP1,Col1a,Col3a,AGT,AGTR1 and TGF-β1 were increased.Compared with SHR group,SHR+Canagliflozin group significantly reduced the proliferation and migration capacity of VSMCs,and the expression ofα-SMA was increased,and the expressions of SPP1,Colla,Col3a,AGT,AGTR1,and TGF-β1 were decreased.Conclusion:Canagliflozin may inhibit the proliferation and migration of hypertensive vascular smooth muscle cells by inhibiting RAAS/TGF-β1 signaling pathway,thereby improving aortic vascular remodeling in SHR.