【摘要】 目的 探讨热休克蛋白70(heat shock protein 70,HSP70)对急性肺损伤(acute lung injury, ALI)小鼠发病的影响及其相关机制。方法 构建ALI模型小鼠，免疫印迹法检测肺组织中HSP70的表达情况，酶联免疫法检测支气管肺泡灌洗液(bronchoalveolar lavage fluid, BALF)中HSP70的分泌情况。ALI小鼠经鼻滴HSP70抗体(anti-HSP70)后，抽取BALF,检测其中肿瘤坏死因子α(tumor necrosis factorα,TNF-α)、白细胞介素6(interleukin 6,IL-6)、白细胞介素1β(interleukin 1β,IL-1β)和蛋白的含量，并计数中性粒细胞的数目；获取肺组织进行苏木精-伊红染色并计算肺湿/干重比。以LPS刺激小鼠肺泡上皮细胞株MLE-12细胞，酶联免疫法检测培养上清液中TNF-α和IL-1β的含量。不同浓度的HSP70(10～500 ng/mL)刺激小鼠肺泡上皮细胞(alveolar epithelial cells, AECs)后，流式细胞术检测AEC吞噬凋亡细胞的情况。结果 与正常对照组小鼠相比，ALI小鼠肺组织中HSP70的表达及BALF中HSP70的分泌均增加(均P<0.05)。与ALI组小鼠相比，经anti-HSP70鼻滴治疗后的ALI小鼠，其BALF中TNF-α、IL-6、IL-1β和蛋白的含量均降低(均P<0.05),中性粒细胞数目减少(P<0.05);其肺组织中炎性细胞浸润减少，肺湿/干重比降低(P<0.05)。与LPS刺激组相比，anti-HSP70+LPS组MLE-12细胞培养上清液中TNF-α和IL-1β含量均减少(均P<0.05)。与未刺激组相比，10～500 ng/mL HSP70刺激组MLE-12细胞吞噬凋亡细胞百分率明显降低，其中以200 ng/mL HSP70刺激组降低最为明显(P<0.01);与未刺激组相比，200 ng/mL HSP70刺激的小鼠原代肺泡上皮细胞吞噬率降低(P<0.01)。结论 HSP70促进ALI小鼠肺部炎症反应，这一效应可能与HSP70降低肺泡上皮细胞吞噬凋亡细胞的功能相关。更多还原

【Abstract】 Objective To explore the role of heat shock protein 70(HSP70)in the pathogenesis of acute lung injury(ALI)mice and its related mechanisms.Methods The ALI mice models were constructed.The expression of HSP70 in lung tissue was detected by Western blotting and the secretion of HSP70 in bronchoalveolar lavage fluid(BALF)was detected by ELISA.After nasal instillation of anti-HSP70 in ALI mice, BALF was extracted to detect the contents of the tumor necrosis factor α(TNF-α),interleukin 6(IL-6),interleukin 1β(IL-1β),total protein and counts of neutrophils.Lung tissue was obtained for HE staining, and wet-to-dry weight(W/D)ratio of the lung was calculated.LPS was used to stimulate the MLE-12 cells in alveolar epithelium of mice, and the contents of TNF-α and IL-1β in the supernatant were detected by ELISA.Mouse alveolar epithelial cells(AECs)were stimulated by using HSP70 at different concentrations(10-500 ng/mL),and then flow cytometry was used to detect the phagocytosis of apoptotic cells by AEC.Results Compared with normal control mice, the expression of HSP70 in lung tissues and the secretion of HSP70 in BALF of ALI mice were increased(both P<0.05).Compared with ALI mice, TNF-α,IL-6,IL-1β and protein in BALF declined in mice that conducted nasal instillation of anti-HSP70(all P<0.05);the number of neutrophils decreased(P<0.05);the infiltration of inflammatory cells and W/D ratio of the lung tissue decreased(both P<0.05).Compared with the LPS stimulation group, the levels of TNF-α and IL-1β in the supernatant of MLE-12 cells in the anti-HSP70+LPS group were reduced(both P<0.05).Compared with the untreated group, the apoptotic cell phagocytosis rate of MLE-12 cells in the 10-500 ng/mL HSP70 stimulation groups was significantly decreased, among which the 200 ng/mL HSP70 stimulation group witnessed the steepest drop(P<0.01).Compared with the untreated group, phagocytic rate in 200 ng/mL HSP70 stimulated primary alveolar epithelial cells(AECs)decreased(P<0.01). Conclusion HSP70 promotes pulmonary inflammatory response in ALI mice, which may be related to HSP70 inhibiting the phagocytic effect of AECs on apoptotic cells.更多还原