抑制桩蛋白磷酸化对机械通气所致肺损伤的效应

The Effects of Inhibition of Paxillin Phosphorylation on Ventilation Associated Lung Injury

目的研究抑制桩蛋白(Paxillin)磷酸化对机械通气相关性肺损伤的效应。方法60只健康雄性SD大鼠随机分为正常对照组、保护性通气组、大潮气量通气组和PP2抑制剂组,每组15只。正常对照组仅做气管切开;保护性通气组进行保护性机械通气2 h,大潮气量通气组进行大潮气量机械通气2 h;PP2抑制剂组通气前1 h腹腔注射酪氨酸蛋白激酶抑制剂PP2并进行大潮气量机械通气2 h。正常对照组在自然吸气2 h,其余组在机械通气结束时处死,光镜观察肺组织病理学改变并进行弥漫性肺泡损伤(DAD)评分;测定髓过氧化物酶(MPO)活性;计算肺湿/干重比值(W/D);酶联免疫吸附试验(ELISA)检测肺泡灌洗液中肿瘤坏死因子(TNF-α)的水平;伊文思蓝法检测肺血管通透性;蛋白免疫印迹法检测磷酸化桩蛋白(p-Paxillin)和Paxillin表达情况;TUNEL法检测原位细胞凋亡。结果大潮气量通气组和PP2抑制剂组的DAD评分、伊文思蓝渗出量、W/D、MPO及TNF-α差异均有统计学意义(P<0.05)。各组细胞原位凋亡率从高到低排序:大潮气量通气组>PP2抑制剂组>保护性通气组>正常对照组。p-Paxillin的表达量在大潮气量通气组中最高,与其他组比较差异有统计学意义(P<0.05)。保护性通气组、大潮气量通气组和PP2抑制剂组间Paxillin的表达量差异无统计学意义(P>0.05)。结论抑制Paxillin磷酸化可以明显改善机械通气相关性肺损伤。

Objective To explore the effects of inhibition of paxillin phosphorylation on ventilation associated lung injury. Methods Sixty healthy male SD rats were randomly divided into four groups,namely a control group,a protective ventilation group,a high tidal volume ventilation group,and an inhibitor group.The rats in the control group received only tracheotomy and breathe naturally. The rats in the protective ventilation group received protective ventilation for 2 hours. The rats in the high tidal volume ventilation group and the inhibitor group received high tidal volume ventilation for 2 hours. The rats in the inhibitor group additionally received intraperitoneal injection of tyrosine protein kinase inhibitor PP2 before ventilation. All rats were sacrificed and the specimens of lung tissue were collected. The pathological changes of lungs were observed under light microscope and estimated by the diffuse alveolar damage（ DAD）score system. The activity of myeloperoxidase（ MPO） and the lungs wet / dry（ W / D） weight ratio were measured. The expression of tumor necrosis factor-α（ TNF-α） in BALF was detected by ELISA. Evans blue（ EB） method was used to detect the pulmonary vascular permeability. The expression levels of phosphorylated paxillin（ p-paxillin） and paxillin in lung tissue were measured by Western blot. Apoptosis in situ was detected by TUNEL. Results There were significant differences in the W / D ratio,the EB extravasation,DAD score,the MPO activity and the TNF-α expression in BALF between the high tidal volume ventilation group and the inhibitor group（ P 0. 05）. The apoptosis rate of each group was sorted from high to low as the high tidal volume ventilation group,the inhibitor group,the protective ventilation group,and the control group. The expression level of p-paxillin was the highest in the high tidal volume ventilation group which was significantly different from other groups（ all P 0. 05）. There was no significant difference in the expression of paxillin in the protective ventilation group,the high tidal volume ventilation group and the inhibitor group（ P 0. 05）. Conclusion Inhibition of paxillin phosphorylation can significantly alleviate mechanical ventilation associated lung injury.