自发性高血压大鼠左室心肌细胞FAK-pTyr576磷酸化及其定位

目的探讨黏着斑激酶酪氨酸576(focal adhesion kinase tyrosine 576,FAK-pTyr576)磷酸化在自发性高血压大鼠(spontaneously hypertensive rats,SHR)心肌肥大发生与发展机制中的作用。方法选择2、6和18月龄雄性SHR为SHR组,相同月龄Wistar-Kyoto(WKY)雄性大鼠作为正常血压对照组(WKY组),每个月龄段大鼠6只。乙醚麻醉,于胸骨剑突下肋骨侧缘剪开,取适量左心室组织,通过免疫荧光标记、共聚焦显微镜及蛋白质印迹(Western blotting,WB)等方法,检测2组不同月龄大鼠心肌细胞中FAK-pTyr576的表达和定位的变化。结果 HE染色发现,与WKY组相比,SHR组左心室心肌细胞不同程度增大。WB检测结果显示:FAK-pTyr576的表达SHR组随大鼠月龄的增加而增强(P0.05),而WKY组不同月龄大鼠间无统计学意义(P0.05);与WKY组比较,SHR组6月龄、18月龄大鼠FAK-pTyr576的表达明显增强(P0.01)。免疫荧光染色结果显示:WKY组不同月龄大鼠心肌细胞FAKpTyr576的表达相似,无明显变化;而SHR组6月龄及18月龄大鼠出现了定位变化。结论 SHR的心肌细胞中存在FAK-pTyr576磷酸化,这可能是高血压致左心室失代偿肥大时心肌细胞黏着斑激酶信号转导通路活化的重要一环。

Phosphorylation and Location of FAK-pTyr576 in Left Ventricular Cardiac Myocytes of Spontaneously Hypertensive Rats

Objective To investigate the effect of FAK-pTyr576 （focal adhesion kinase tyrosine 576） phosphoryla- tion on the pathogenesis of left ventricular hypertrophy cardiac myocyte in spontaneously hypertensive rats. Methods Male spontaneously hypertensive rats （spontaneously hypertensive rats, SHR） of 2, 6 and 18 month-old were selected as SHR groups, and the same month-old Wistar-Kyoto （WKY） male rats were chosen as normotensive control groups （WKY groups） , and each age group had 6 rats. After ether anesthesia, the lower edge of the sternum xiphoid lateral margin was cut, and ap- propriate ventricular tissues were taken out. Expressions and subcellular locations of FAK-pTyr576 were determined by using methods of immunofluorescent labeling, confocal microscopy and Western Blotting （WB） in each age group. Results HE staining results showed that different degrees of left ventricular hypertrophy could be found in SHR groups compared with those in WKY groups. WB results showed that the expression of FAK-pTyr576 increased with age in months in SHR groups （P 〈 0.05 ） , but the differences in WKY rats of different age groups showed no statistical significances （ P 〉 0.05 ） ; compared with those in WKY groups, in SHR groups FAK-pTyr576 expressions of 6 and 18 month-old rats were significantly enhanced （P 〈 O. O1 ）. Immunofluorescence staining results showed that cardiomyocytes FAK-pTyr576 expressions of different age groups were similar without obvious changes in WKY groups; while location changes were found in 6 and 18 month-old rats in SHR groups. Conclusion SHR cardiomyocytes have FAK-pTyr576 phosphorylation, which may be an important part of cell adhesion plaque kinase signal transduetion pathway activation induced by left ventricular deeompensation in hypertensive cardiac hyper- trophy.