Awolesi M A, Sessa W C, Sumpio B E
Department of Surgery, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
J Clin Invest. 1995 Sep;96(3):1449-54. doi: 10.1172/JCI118181.
In vivo, endothelial cells (EC) are subjected to hemodynamic forces which may influence the production of nitric oxide. This study was designed to examine the effect of cyclic strain on the expression of endothelial nitric oxide synthase (eNOS) in cultured bovine aortic EC. EC were grown on flexible membranes which were subjected to deformation at 60 cycles/min with -5 or -20 kPa of vacuum. This results in an average strain of 6 and 10%, respectively, which is transmitted to the attached cells. Northern blot analysis of total cytosolic RNA demonstrated an increase in eNOS gene expression with both strain regimens but the increase with 10% average strain was greater than that at 6%. Nuclear runoff transcription assays confirmed the induction of eNOS transcripts. Western blot analysis showed an increase in eNOS level after 24 h of cyclic 10% average strain compared with controls or 6% average strain. Immunohistochemical staining of EC for eNOS was increased in the high strain periphery (7-24% strain) of membranes deformed with -20 kPa vacuum. These results demonstrate that cyclic strain upregulates the expression of eNOS transcripts and protein levels in bovine aortic EC thus emphasizing the importance of hemodynamic forces in the regulation of eNOS in vivo.
在体内，内皮细胞（EC）受到血流动力学力的作用，这些力可能会影响一氧化氮的产生。本研究旨在检测循环应变对培养的牛主动脉内皮细胞中内皮型一氧化氮合酶（eNOS）表达的影响。内皮细胞生长在柔性膜上，该膜以60次/分钟的频率在-5或-20 kPa的真空度下发生变形。这分别导致平均应变6%和10%，并传递给附着的细胞。对总胞质RNA进行的Northern印迹分析表明，两种应变方案均使eNOS基因表达增加，但平均应变10%时的增加幅度大于6%时的增加幅度。核转录延伸分析证实了eNOS转录本的诱导。蛋白质免疫印迹分析显示，与对照组或平均应变6%相比，在平均应变10%的循环作用24小时后，eNOS水平增加。在用-20 kPa真空度变形的膜的高应变周边（应变7%-24%）区域，对内皮细胞进行eNOS免疫组织化学染色增加。这些结果表明，循环应变上调了牛主动脉内皮细胞中eNOS转录本的表达和蛋白质水平，从而强调了血流动力学力在体内eNOS调节中的重要性。
