Objective: To investigate changes of NLRP3 signal transduction pathway of acute lung injury induced by phosgene to analyze NLRP3-mediated IL-1β release inflammatory process in rats. Methods: Rats were randomly divided into two groups, 10 rats in the Air group that consists of the rats with air exposure, 10 rats in the Psg group that consists of the rats with phosgene exposure at 8.33 g/m(3) for 5 min. The specimens of serum, bronchoalveolar lavage fluid (BALF) and lung were collected after 6h. Morphological changes were observed by HE staining. The expression of NLRP3 in the lung of two groups was detected by immunohistochemistry. NLRP3、ASC and caspase-1 expression in the lung tissue was quantified by Western blot. Reverse transcription-polymerase chain reaction (RT-PCR) were used to detect the expression of NLRP3、ASC and caspase-1 mRNA in the lung tissue. The concentrations of IL-1β、IL-18 and IL-33 in the serum and BALF were measured by enzyme-linked immunosorbent assay. RT-PCR were used to detect the expression of IL-1β、IL-18 and IL-33 mRNA in the lung tissue. Results: We successfully replicated the model of phosgene-induced ALI in rats. Morphological of HE staining after phosgene exposure to 6 h observed inflammatory cell infiltration in lung tissue in Phosgene group. Immunohistochemical staining results showed that there were many NLRP3 positive cells in lung tissue in Phosgene group. The levels of NLRP3 and caspase-1 mRNA and protein expression in lung were significantly increased (P<0.05) in Phosgene group, but no significant change was observed in lung ASC mRNA and protein expression (P>0.05) . Compared with Air group, the serum, BALF and lung tissue of IL-1β、IL-18 and IL-33 mRNA and protein expression were significantly increased (P<0.01) in Phosgene group. Conclusion: NLRP3-mediated inflammatory response probably involved in the process of the phosgene, so it maybe one of the pathogenesis of acute lung injury.
目的： 探讨NOD样受体热蛋白结构域相关蛋白3（NLRP3）炎症小体介导的白细胞介素-1β（IL-1β）等炎性因子释放在大鼠光气致急性急性肺损伤（ALI）发病机制中的作用。 方法： 将20只大鼠随机分为2组，空气对照组（吸入与光气染毒组同等流量的空气）10只，光气染毒组（吸入8.33 mg/L纯度为100%的光气5 min）10只。染毒6 h后收集血清、支气管肺泡灌洗液（BALF）和肺组织。制作肺脏石蜡切片，HE染色观察形态学改变，免疫组化检测肺组织中NLRP3蛋白表达水平。蛋白质免疫印迹试验（Western blot）技术和反转录-聚合酶链反应（RT-PCR）方法检测肺组织中NLRP3、凋亡相关斑点样蛋白（ASC）和天冬氨酸特异性半胱氨酸蛋白酶1（caspase-1）mRNA和蛋白的表达。采用双抗体夹心酶标免疫分析法（ELISA法）测定各组血清和BALF中IL-1β、IL-18和IL-33水平；反转录-聚合酶链反应（RT-PCR）方法对肺组织IL-1β、IL-18和IL-33 mRNA水平进行半定量研究。 结果： 成功复制光气吸入性肺损伤模型。染毒6h后HE染色形态学观察可见，光气染毒组肺组织中有大量炎性细胞浸润，免疫组化染色结果显示，光气染毒组大鼠肺泡间隔增厚，肺组织中可见较多NLRP3阳性细胞。与空气对照组（mRNA：NLRP3为21.49±1.44，Caspase-1为23.38±1.37；蛋白含量的相对值：NLRP3为0.090 6±0.025 7，Caspase-1为0.094 2±0.034 6）比较，光气染毒组肺组织中NLRP3和caspase-1 mRNA和蛋白表达量（mRNA：NLRP3为28.19±1.11，caspase-1为28.67±0.89；蛋白含量的相对值：NLRP3为0.655 6±0.171 4，caspase-1为0.964 1±0.284 6）明显升高，差异有统计学意义（P<0.05）；ASC mRNA和蛋白表达量无明显变化，差异无统计学意义（P>0.05）。与空气对照组（肺组织mRNA：IL-1β为15.25±0.72、IL-18为23.16±0.60、IL-33为22.48±1.25；血清IL-1β为109.6±1.9、IL-18为36.12±1.49、IL-33为11.30±1.27；BALF：IL-1β为170.4±3.0、IL-18为48.15±3.08、IL-33为21.00±1.43）比较，光气染毒组肺组织IL-1β、IL-18和IL-33 mRNA（IL-1β为22.68±1.16、IL-18为30.35±1.23、IL-33为31.44±1.21）表达量明显升高，血清和BALF中IL-1β、IL-18和IL-33蛋白含量（血清：IL-1β为418.7±13.9、IL-18为140.4±5.0、IL-33为25.70±1.16；BALF：IL-1β为615.8±24.9、IL-18为151.60±6.38、IL-33为38.30±1.248）明显升高，差异均有统计学意义（P<0.01）。 结论： NLRP3炎症小体介导炎性反应可能参与了光气致急性肺损伤的发病过程，可能是急性肺损伤的发病机制之一。.
Keywords: Acute lung injury; Inflammation; NLRP3 Inflammasome; Phosgene.