We have studied the prophylactic efficacy of curcumin to ameliorate the impairment of tight junction protein integrity and fluid clearance in lungs of rats under hypoxia. A549 cells wereexposed to 3 % O2 for 1 h, 3 h, 6 h, 12 h, 24 h and 48 h and rats were exposed to 7620 m for 6 h. NF-κB, Hif-1α and their related genes, tight junction protein (TJ) (ZO-1, JAM-C, claudin-4 and claudin-5, claudin-18) expressions were determined in A549 cells and lungs of rats by western blotting, ELISA and their activity by reporter gene assay, siRNAp65 knock out. Tissue specific localization of tight junction protein was determined by immunohistochemistry and immunoflorescence. Further transmission electron microscopy (TEM) was used to visualize the TJ structures between pulmonary epithelial cells. Blood gas and hematological parameters were also assessed. Later we checked, whether prior treatment with curcumin can restore the altered alveolar epithelial barrier integrity that is compromised through inflammatory mediators under hypoxia, A549 cells were pre-treated (1 h) with 10 μM curcumin and rats with 50 mg curcumin/kg BW and exposed to hypoxia. Curcumin pre-treatment both in vitro and in vivo showed significant changes in TJ protein integrity, attenuated NF-κB activity with reduced expression of its regulatory genes in lung tissues, serum and bronchoalveolar lavage fluid (BALF) along with stabilized HIF-1α levels under hypoxia. NF-κB inhibitors MG132, SN50 or siRNA mediated p65 knock down significantly reduced the dextran FITC influx into the lungs. The present study indicates that, curcumin prophylaxis augments alveolar epithelial barrier integrity and alveolar fluid clearance under hypoxia.

中文翻译：

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姜黄素的预防可翻新缺氧条件下肺泡上皮屏障的完整性和肺泡液的清除。

我们研究了姜黄素在缺氧条件下改善大鼠肺部紧密连接蛋白完整性和液体清除的预防作用。将A549细胞暴露于3％O2中1h，3h，6h，12h，24h和48h，将大鼠暴露于7620m中6h。NF-κB，Hif-1α及其相关基因，紧密连接蛋白（TJ）（ZO-1，JAM-C，claudin-4和claudin-5，claudin-18）的表达可以通过A549细胞和肺的表达来检测。免疫印迹，ELISA及其活性，通过报道基因检测siRNAp65敲除。通过免疫组织化学和免疫荧光测定紧密连接蛋白的组织特异性定位。进一步的透射电子显微镜（TEM）用于观察肺上皮细胞之间的TJ结构。还评估了血气和血液学参数。后来我们检查了姜黄素的先前治疗是否可以恢复缺氧条件下炎症介质损害的改变的肺泡上皮屏障完整性，用10μM姜黄素预处理A549细胞（1小时），用50 mg姜黄素/ kg体重对大鼠A549细胞进行预处理（1小时）。暴露于缺氧状态。姜黄素预处理在体内和体外均显示出TJ蛋白完整性的显着变化，NF-κB活性减弱，其在肺组织，血清和支气管肺泡灌洗液（BALF）中的调节基因表达降低以及HIF-1α水平稳定在缺氧。NF-κB抑制剂MG132，SN50或siRNA介导的p65敲低可显着减少右旋糖酐FITC流入肺部。本研究表明，姜黄素预防可增强缺氧条件下肺泡上皮屏障的完整性和肺泡液清除率。