苦瓜蛋白对低剪切应力下apoE^(−/−)小鼠内皮-间充质转化的影响

Effect of momordicin on endothlial-mesenchymal transition in apoE−/−mice under low shear stress

目的:探讨苦瓜蛋白对低剪切应力内皮-间充质转化的影响,探讨其抗动脉粥样硬化作用新机制。方法:构建apoE^(−/−)小鼠颈动脉低剪切应力模型,将20只apoE^(−/−)小鼠随机分为苦瓜蛋白组和模型组,均予以高脂饮食喂养,苦瓜蛋白组腹腔注射苦瓜蛋白(5 mg·kg^(−1)·d^(−1)),模型组注射等体积的生理盐水。ELISA检测apoE^(−/−)小鼠血浆中炎症因子水平;Western blot和免疫荧光检测颈总动脉中内皮及间充质标志物表达和共定位情况,以及细胞间黏附分子1(ICAM-1)和血管细胞黏附分子1(VCAM-1)表达水平。结果:模型组低剪切应力下内皮完整性受损,且出现了动脉粥样硬化病变和内皮-间充质转化,但均可被苦瓜蛋白可所抑制。与模型组比较,苦瓜蛋白组内皮标志物血管内皮钙黏蛋白(VE-cadherin)表达显著上调(P<0.05),间充质标志物α-平滑肌肌动蛋白(α-SMA)表达显著下调(P<0.05)。机制研究发现,苦瓜蛋白可降低血清炎症因子肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)及IL-1β水平,以及黏附分子ICAM-1和VCAM-1的表达水平。结论:苦瓜蛋白能减轻低剪切应力下内皮-间充质转化,与其抑制炎症因子和黏附分子的表达有关。

AIM:To investigate the effect of momordicin on the endothelial-mesenchymal transition(EnMT)of low shear stress endothelium,and to explore its new mechanism of anti-atherosclerosis.METHODS:carotid artery low shear stress model of apoE^(−/−)mice was constructed.The apoE^(−/−)mice(n=20)were randomly divided into momordicin group and model group,all fed with high-fat diet.The mice in momordicin group were intraperitoneally injected with momordicin at 5 mg·kg^(−1)·d^(−1),while the mice in model group was injected with an equal volume of normal saline.ELISA was used to measure the levels of inflammatory factors in the plasma of apoE^(−/−)mice.Western blot and immunofluorescence were used to detect the expression and colocalization of endothelial and mesenchymal markers in the common carotid artery,and the expression levels of adhesion molecules intercellular adhesion molecule-1(ICAM-1)and vascular cell adhesion molecule-1(VCAM-1).RESULTS:The endothelial integrity was impaired under low shear stress in model group,and the atherosclerotic lesions and EnMT were observed,which were all inhibited by momordicin.Compared with model group,the expression of VE-cadherin in momordicin group was significantly up-regulated(P<0.05),and the expression of mesenchymal markerα-smooth muscle actin(α-SMA)was significantly down-regulated(P<0.05).Moreover,momordicin decreased the serum levels of inflammatory factors tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and IL-1β,and the levels of adhesion molecules ICAM-1 and VCAM-1 were also reduced.CONCLUSION:Momordicin alleviates EnMT under low shear stress,which is related to the inhibition of inflammatory factor and adhesion molecule expression.