ROCK介导缓激肽开放SD大鼠血肿瘤屏障

目的利用ROCK的特异性抑制剂Y-27632,研究ROCK是否介导缓激肽开放血肿瘤屏障。方法应用ROCK的特异性抑制剂Y-27632预处理大鼠原代脑微血管内皮细胞后,用缓激肽诱导血肿瘤屏障开放,测量跨内皮阻抗值(TEER),辣根过氧化物酶(HRP)渗漏量,分析血肿瘤屏障的通透性的改变;应用Western-blot法检测紧密连接相关蛋白ZO-1的表达;应用免疫荧光方法观察原代大鼠脑微血管内皮细胞紧密连接相关蛋白ZO-1和丝状肌动蛋白结构和分布的改变。结果 Y-27632显著抑制缓激肽诱导TEER值的降低,HRP的升高;Y-27632显著抑制ZO-1的表达;Y-27632抑制ZO-1由内皮细胞的边缘向细胞质转移,抑制丝状肌动蛋白由细胞膜边缘向细胞中央区分布,应力纤维形成明显减少。结论 ROCK介导缓激肽开放血肿瘤屏障。

ROCK mediates bradykinin-induced opening of blood-tumor barrier in SD rats

Objective To investigate if ROCK mediates bradykinin(BK)-induced opening of blood-tumor barrier (BTB) using a specific ROCK inhibitor, Y-27632 in SD rats. Methods Rat brain microvascular endothelail cells (RBMECs) were pretreated with a specific ROCK inhibitor, Y-27632 and then treated with bradykinin(BK) for 15 min. Horseradish peroxidase(HRP) flux and trans epithelial electric resistance(TEER) assays were used to reveal BTB permeability. The protein expression level of ZO-1 was observed as assessed by western blot. The stress fiber formation and distribution of Factin and ZO-1 were assessed by immunofluorescence microscopy. Results TY-27632 could partially inhibit BK-induced endothelial leakage and decrease of TEER values in RBMECs , and inhibit decrease of ZO-1 protein expression level, and inhibit BK-induced relocation of ZO-1 from cellular borders into the cytoplasm, and inhibit stress fiber formation in RBMECs. Conclusion ROCK mediates BK-induced opening of blood-tumor barrier .