Effects and mechanisms of alveolar type II epithelial cell apoptosis in severe pancreatitis- induced acute lung injury
Effects and mechanisms of alveolar type II epithelial cell apoptosis in severe pancreatitis- induced acute lung injury
复制标题
肺泡II型上皮细胞凋亡对重症胰腺炎急性肺损伤的影响及机制
DOI：
10.3892/etm.2013.1453
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发表时间：
2014-03-01
影响因子：
2.7
通讯作者：
Guo, Huishu
中科院分区：
文献类型：
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作者：
Liu, Geliang;Zhang, Jingwen;Guo, Huishu
本研究旨在探讨肺泡Ⅱ型上皮细胞（AEC Ⅱ）凋亡在重症胰腺炎急性肺损伤（ALI）中的作用及清胰汤的干预作用。在雄性Sprague-Dawley大鼠中建立SAP模型。采用免疫组化方法观察胰腺和肺组织的病理变化。流式细胞术检测AEC II凋亡，激光扫描共聚焦显微镜检测AEC II内游离Ca2+浓度。采用放射免疫法测定血清TNF-α含量。采用定量聚合酶链反应（qPCR）和免疫组织化学方法检测肺组织Bax和caspase-8的mRNA和蛋白表达水平。重症急性胰腺炎（SAP）组肺组织切片的苏木精-伊红染色显示与对照组织相同的病理变化，与急性肺损伤（ALI）一致。流式细胞仪检测SAP组AEC Ⅱ凋亡率较对照组明显增高（P <0.01）。激光扫描共聚焦显微镜显示SAP组AECs II内游离Ca~（2+）浓度较对照组显著升高（P <0.01）。放射免疫分析显示SAP组TNF-α水平较对照组显著升高（P <0.01），qPCR结果显示SAP组AECs II中Bax和caspase-8凋亡基因表达水平较对照组显著升高（P <0.01）。与SAP模型组相比，药物治疗后上述指标显著降低。这些结果表明，AEC II凋亡参与了与SAP相关的ALI过程。线粒体途径和死亡受体途径可能在AEC II凋亡中起关键调节作用。使用QYT可显著减轻肺损伤的程度。
This study aimed to examine the role of alveolar type II epithelial cell (AEC II) apoptosis in severe pancreatitis-induced acute lung injury (ALI) and the intervening role of Qingyi decoction (QYT). An SAP model was established in male Sprague-Dawley rats. Immunohistochemical analysis was conducted to observe the pathological changes in the pancreas and lung tissue. AEC II apoptosis was detected by flow cytometry and the free Ca2+ concentration in AECs II was determined by laser scanning confocal microscopy. A radioimmunoassay was performed to determine serum TNF-α content. Quantitative polymerase chain reaction (qPCR) and immunohistochemical analysis were performed to detect the mRNA and protein expression levels of Bax and caspase-8 in the lung tissue. Hematoxylin and eosin staining of lung tissue sections in the severe acute pancreatitis (SAP) group showed pathological changes from control tissue, consistent with acute lung injury (ALI). Flow cytometry showed that the level of AEC II apoptosis in the SAP group was significantly increased compared with that in the control group (P<0.01). Laser scanning confocal microscopy indicated that the free Ca2+ concentration in the AECs II of the SAP group was also significantly increased compared with that in the control (P<0.01). Radioimmunoassay demonstrated that the TNF-α levels were significantly increased in the SAP group compared with those in the control group (P<0.01), and qPCR results showed that the levels of Bax and caspase-8 apoptotic gene expression in the AECs II of the SAP group were significantly elevated (P<0.01). The aforementioned indicators were significantly lower following drug treatment compared with the levels observed in the SAP model group. These results suggest that AEC II apoptosis is involved in the ALI procedure associated with SAP. The mitochondrial pathway and death receptor pathway may have key regulatory roles in AEC II apoptosis. The use of QYT may significantly reduce the extent of lung injury.