【摘要】 目的探究增龄和高血压对胸主动脉血管平滑肌细胞(VSMC)表型转换的影响及磷脂酰肌醇激酶(PI3K/Akt)和丝裂原活化蛋白激酶(MAPK)信号通路对VSMC表型的调控。方法选取1、3、9、16月龄的雄性Wistar Kyoto大鼠(WKY)和自发性高血压大鼠(SHR)各12只,尾动脉无创测定血压,取各组大鼠的胸主动脉进行实验。HE染色测量胸主动脉的管壁厚度;免疫组织化学染色检测VSMC表型标志蛋白α平滑肌肌动蛋白(α-SMactin)、调宁蛋白、骨桥蛋白(OPN)的表达和分布;Western blot检测VSMC表型标志蛋白α-SM-actin、调宁蛋白、OPN及信号蛋白p-Akt、内皮型一氧化氮合酶(eNOS)、p-42/44ERK、p-p38MAPK的表达量。结果 HE染色结果显示,增龄导致管壁厚度增加,且在9月龄时WKY和SHR出现显著差异(P<0.01)。免疫组织化学染色和Western blot结果表明,3月龄后,WKY和SHR的α-SM-actin、调宁蛋白表达量随月龄增加出现下调,而OPN出现上调;p-Akt、eNOS的蛋白表达量随月龄增加逐渐下调,p-42/44ERK、p-p38MAPK蛋白表达量随月龄增长逐渐上调,且3月龄时两组已有显著差异(P<0.01)。结论增龄和高血压均导致大鼠胸主动脉VSMC收缩表型标志蛋白α-SM-actin、调宁蛋白的表达下调,合成表型标志蛋白OPN的表达上调,二者的交互作用更显著。VSMC的表型转换可能是通过PI3K/Akt和MAPK信号通路间的平衡作用进行调控的。更多还原

【Abstract】 Aim To explore the effects of aging and hypertension on phenotypic switching of thoracic aortic vascular smooth muscle cell( VSMC) and regulation of VSMC phenotype by phosphatidylinositol 3-kinase( PI3K/Akt) and mitogen-activated protein kinase( MAPK) signaling pathway. Methods Male Wistar Kyoto rats( WKY) and spontaneously hypertensive rats( SHR) were studied at 1,3,9,16 months of age,and each group had 12 rats. Blood pressure was noninvasively measured in the caudal artery. The thoracic aorta of rats in each group was taken for the experiment. HE staining was used to measure the wall thickness of the thoracic aorta. The expression and distribution of VSMC phenotype marker proteins α-smooth muscleactin( α-SM-actin),calponin and osteopontin( OPN) were detected by immunohistochemical staining. Western blot was used to detect the expression of VSMC phenotype marker protein α-SM-actin,calponin,OPN,and signal proteins p-Akt,endothelial nitric oxide synthase( e NOS),p-42/44 ERK and p-p38 MAPK. Results HE staining showed that aging resulted in an increase in the thickness of vascular wall,and at 9 months old,there was a significant difference between WKY and SHR( P<0.01). Immunohistochemical staining and Western blot showed that after 3 months old,the expressions of α-SM-actin and calponin in WKY and SHR decreased with the increase of age,while OPN increased; The expressions of p-Akt and e NOS proteins gradually decreased with the increase of age,and the expressions of p-42/44 ERK and p-p38 MAPK proteins increased gradually with the increase of age; At 3 months old,there was significant difference between the two groups( P<0.01). Conclusion Aging and hypertension all contribute to the decreases in expressions of VSMC contractile phenotype marker proteins α-SM-actin and calponin,and the increase in the expression of VSMC synthetic phenotypic marker protein OPN in rat thoracic aorta. The interaction between aging and hypertension is more significant. The phenotypic switching of VSMC may be mediated by the balance between PI3K/Akt and MAPK signaling pathways.更多还原