Wu Mack H, Guo Mingzhang, Yuan Sarah Y, Granger Harris J
Cardiovascular Research Institute and Department of Medical Physiology, College of Medicine, Texas A&M University System Health Science Center, 702 Southwest HK Dodgen Loop, Temple, TX 76504, USA.
J Physiol. 2003 Nov 1;552(Pt 3):691-9. doi: 10.1113/jphysiol.2003.048405. Epub 2003 Aug 29.
Focal adhesion kinase (FAK) is known to mediate endothelial cell adhesion and migration in response to vascular endothelial growth factor (VEGF). The aim of this study was to explore a potential role for FAK in VEGF regulation of microvascular endothelial barrier function. The apparent permeability coefficient of albumin (Pa) was measured in intact isolated porcine coronary venules. Treating the vessels with VEGF induced a time- and concentration-dependent increase in Pa. Inhibition of FAK through direct delivery of FAK-related non-kinase (FRNK) into venular endothelium did not alter basal barrier function but significantly attenuated VEGF-elicited hyperpermeability. Furthermore, cultured human umbilical vein endothelial monolayers displayed a similar hyperpermeability response to VEGF which was greatly attenuated by FRNK. Western blot analysis showed that VEGF promoted FAK phosphorylation in a time course correlating with that of venular hyperpermeability. The phosphorylation response was blocked by FRNK treatment. In addition, VEGF stimulation caused a significant morphological change of FAK from a punctate pattern to an elongated, dash-like staining that aligned with the longitudinal axis of the cells. Taken together, the results suggest that FAK contributes to VEGF-elicited vascular hyperpermeability. Phosphorylation of FAK may play an important role in the signal transduction of vascular barrier response to VEGF.
已知粘着斑激酶（FAK）可介导内皮细胞对血管内皮生长因子（VEGF）产生反应时的粘附与迁移。本研究的目的是探究FAK在VEGF对微血管内皮屏障功能的调节中可能发挥的作用。在完整分离的猪冠状动脉小静脉中测量白蛋白的表观渗透系数（Pa）。用VEGF处理血管会导致Pa呈时间和浓度依赖性增加。通过将FAK相关非激酶（FRNK）直接递送至小静脉内皮中来抑制FAK，并不会改变基础屏障功能，但会显著减弱VEGF引发的高通透性。此外，培养的人脐静脉内皮单层对VEGF表现出类似的高通透性反应，而FRNK可大大减弱这种反应。蛋白质印迹分析表明，VEGF促进FAK磷酸化的时间进程与小静脉高通透性的时间进程相关。FRNK处理可阻断磷酸化反应。此外，VEGF刺激导致FAK的形态发生显著变化，从点状模式变为与细胞纵轴对齐的细长的、短划线样染色。综上所述，结果表明FAK促成了VEGF引发的血管高通透性。FAK的磷酸化可能在血管屏障对VEGF反应的信号转导中起重要作用。
