Background p120 catenin （p120ctn） is an adheren junction protein that regulates barrier function, but its role has not been explored in alveolar edema induced by ventilation. We measured stretch-induced cell gap for...Background p120 catenin （p120ctn） is an adheren junction protein that regulates barrier function, but its role has not been explored in alveolar edema induced by ventilation. We measured stretch-induced cell gap formation in MLE 12 cells due to the loss of p120. We hypothesized that alveolar permeability was increased by high tung inflation associated with alveolar epithelia cell tight junctions being destroyed, which resulted from the loss of p120. Methods Cultured MLE12 cells were subjected to being stretched or un-stretched （control） and some cells were pretreated with pp2 （c-src inhibitor）. After the end of stretching for 0, 1, 2, and 4 hours, the cells were lysed, and p120 expression and c-src activation was determined by Western blotting analysis. In vivo, SD rats were taken to different tidal volumes （Vt 7 ml/kg or 40 ml/kg, PEEP=0, respiratory rate 30-40 betas/min） for 0, 1, 2, and 4 hour and some were pretreated with pp2, and alveolar edema was calculated. Rerults It was found that p120 expression was reduced and c-src activation increased in a time-dependent and strain- dependent manner due to cyclic-stretch of the alveolar epithelial cells. These changes could be reversed by inhibition of c-src. We obtained similar changes in rats when they were subjected to large tidal volumes and the alveolar edema increased more than in rats in the low Vt group. Pretreated the rats with inhibition of c-src had less pulmonary edema induced by the high tidal volume ventilation. Conclusions Cyclic stretch MLE 12 cells induced the loss of p120 and may be the same reason by high tidal volume ventilation in rats can aggravate alveolar edema. Maintenance of p120 expression may be a novel therapeutic strategy for the prevention and treatment of ventilation induced lung injury （VILI）.展开更多
目的布比卡因是长效酰胺类局麻药,本研究旨在观察布比卡因对人肺上皮细胞短路电流的影响,并探讨可能的机制。方法应用尤斯灌流室装置测定H441单层细胞的短路电流。由总电流减去阿米洛利抑制后的电流算得阿米洛利敏感性电流,以用药前H44...目的布比卡因是长效酰胺类局麻药,本研究旨在观察布比卡因对人肺上皮细胞短路电流的影响,并探讨可能的机制。方法应用尤斯灌流室装置测定H441单层细胞的短路电流。由总电流减去阿米洛利抑制后的电流算得阿米洛利敏感性电流,以用药前H441单层细胞的阿米洛利敏感性电流初始值为100%对照。用100μmol·L^(-1)布比卡因处理H441细胞,在0、15、30、60 min 4个时间点提取蛋白用于Western blot,研究布比卡因对ERK1/2蛋白磷酸化的影响。结果布比卡因能够剂量依赖性抑制H441单层细胞的短路电流,此电流可被阿米洛利抑制;Western blot结果显示,布比卡因能够促进ERK1/2蛋白磷酸化。结论布比卡因通过抑制人肺上皮细胞阿米洛利敏感性电流而降低肺泡上皮离子转运,其机制可能与其促进ERK1/2蛋白磷酸化有关。临床上对伴有肺部疾患的病人应用布比卡因时应考虑其可能对肺泡上皮液体清除的影响。展开更多
目的观察大鼠油酸型肺损伤时肺泡上皮通透性和肺泡上皮液体清除能力的变化,旨在阐明肺泡上皮屏障功能在渗透性肺水肿发生中的作用。方法W istar大鼠35只,随机分为正常对照组和油酸致伤组。经股静脉注入油酸0.25 m l/kg复制急性肺损伤模...目的观察大鼠油酸型肺损伤时肺泡上皮通透性和肺泡上皮液体清除能力的变化,旨在阐明肺泡上皮屏障功能在渗透性肺水肿发生中的作用。方法W istar大鼠35只,随机分为正常对照组和油酸致伤组。经股静脉注入油酸0.25 m l/kg复制急性肺损伤模型,分别于伤后3、6、12、24 h测定肺泡上皮通透性(AEP)、肺泡内液体清除率(ALCR)、总肺水量(TLW)和肺血管外肺水量(EVLW)。结果静注油酸后,大鼠AEP进行性增高,ALCR呈现逐渐下降趋势;同时TLW及EVLW逐渐增加。上述指标均于24 h时相点改变最为显著。伤后24 h,AEP较对照组增高68.7%,TLW和EVLW分别增加44.6%和92.0%,ALCR降低49.4%。结论油酸致伤后,肺泡上皮屏障功能障碍与肺泡水肿形成密切相关,详细机制有待于进一步研究。展开更多
基金This study was supported by a grant from the Natural Science Foundation of Shandong Province,China
文摘Background p120 catenin （p120ctn） is an adheren junction protein that regulates barrier function, but its role has not been explored in alveolar edema induced by ventilation. We measured stretch-induced cell gap formation in MLE 12 cells due to the loss of p120. We hypothesized that alveolar permeability was increased by high tung inflation associated with alveolar epithelia cell tight junctions being destroyed, which resulted from the loss of p120. Methods Cultured MLE12 cells were subjected to being stretched or un-stretched （control） and some cells were pretreated with pp2 （c-src inhibitor）. After the end of stretching for 0, 1, 2, and 4 hours, the cells were lysed, and p120 expression and c-src activation was determined by Western blotting analysis. In vivo, SD rats were taken to different tidal volumes （Vt 7 ml/kg or 40 ml/kg, PEEP=0, respiratory rate 30-40 betas/min） for 0, 1, 2, and 4 hour and some were pretreated with pp2, and alveolar edema was calculated. Rerults It was found that p120 expression was reduced and c-src activation increased in a time-dependent and strain- dependent manner due to cyclic-stretch of the alveolar epithelial cells. These changes could be reversed by inhibition of c-src. We obtained similar changes in rats when they were subjected to large tidal volumes and the alveolar edema increased more than in rats in the low Vt group. Pretreated the rats with inhibition of c-src had less pulmonary edema induced by the high tidal volume ventilation. Conclusions Cyclic stretch MLE 12 cells induced the loss of p120 and may be the same reason by high tidal volume ventilation in rats can aggravate alveolar edema. Maintenance of p120 expression may be a novel therapeutic strategy for the prevention and treatment of ventilation induced lung injury （VILI）.
文摘目的布比卡因是长效酰胺类局麻药,本研究旨在观察布比卡因对人肺上皮细胞短路电流的影响,并探讨可能的机制。方法应用尤斯灌流室装置测定H441单层细胞的短路电流。由总电流减去阿米洛利抑制后的电流算得阿米洛利敏感性电流,以用药前H441单层细胞的阿米洛利敏感性电流初始值为100%对照。用100μmol·L^(-1)布比卡因处理H441细胞,在0、15、30、60 min 4个时间点提取蛋白用于Western blot,研究布比卡因对ERK1/2蛋白磷酸化的影响。结果布比卡因能够剂量依赖性抑制H441单层细胞的短路电流,此电流可被阿米洛利抑制;Western blot结果显示,布比卡因能够促进ERK1/2蛋白磷酸化。结论布比卡因通过抑制人肺上皮细胞阿米洛利敏感性电流而降低肺泡上皮离子转运,其机制可能与其促进ERK1/2蛋白磷酸化有关。临床上对伴有肺部疾患的病人应用布比卡因时应考虑其可能对肺泡上皮液体清除的影响。
