摘要
目的 观察吸入高浓度氧所致急性肺损伤中细胞死亡方式 ,探讨细胞凋亡在急性肺损伤中所起的作用。方法 将 5 4只小鼠置于密闭的高浓度氧气室 (氧浓度 >98% ) ,另 18只小鼠呼吸正常空气作为对照组 ;分别于 2 4、4 8和 72h取出小鼠评价肺损伤及气道上皮脱落程度 ;用脱氧核糖核苷酸末端转移酶介导的末端标记法 (TUNEL)检测损伤的肺组织中细胞凋亡的发生程度 ;逆转录 聚合酶链反应 (RT PCR)及免疫组织化学测定肺组织中caspase 3的表达及组织分布。 结果 高氧能引起急性肺损伤 ,伴部分支气管上皮从基底膜分离甚至脱落 ;TUNEL分析显示当暴露于高氧 4 8h后 ,支气管上皮细胞及肺泡上皮细胞凋亡指数分别为 0 5 1± 0 10和 0 4 6± 0 0 8,较对照组 (0 0 4±0 0 2 ,0 0 2± 0 0 1)显著增加 (P均 <0 0 1) ;RT PCR结果显示caspase 3mRNA表达量在暴露于高氧4 8h后达 0 5 3± 0 0 9,较对照组 (0 34± 0 0 7)显著增加 (P <0 0 5 ) ,72h达最高 (0 6 0± 0 0 8) ;免疫组织化学研究结果显示在损伤的肺组织中 ,caspase 3蛋白表达于气道上皮细胞、肺泡上皮细胞和巨噬细胞的胞浆及细胞核中 ,caspase 3蛋白在气道上皮细胞的表达在高氧环境下 2 4h达 4 1 6 2± 3 4 6 ,较对照组 (15 86± 1 84 )显著升高
Objective To investigate the pathways to cell death in hyperoxia-induced lung injury and the functional significance of apoptosis in vivo in response to hyperoxia. Methods Seventy-two mice were exposed in sealed cages >98% oxygen(for 24-72 h) or room air,and the severity of lung injury and epithelium sloughing was evaluated. The extent and location of apoptosis in injured lung tissues were studied by terminal transferase dUTP end labeling assay(TUNEL),reverse transcript-polymerase chain reaction (RT- PCR) and immunohistochemistry. Results Hyperoxia caused acute lung injury;the hyperoxic stress resulted in marked epithelium sloughing. TUNEL assay exhibited increased apoptosis index both in alveolar epithelial cells and bronchial epithelial cells in sections from mice after 48 h hyperoxia compared with their control group(0.51±0.10,0.46±0.08 verse 0.04±0.02,0.02±0.01). This was accompanied by increased expression of caspase-3 mRNA in lung tissues after 48 h hyperoxia compared with their control group(0.53±0.09 verse 0.34±0.07),the expression was higher at 72 h of hyperoxia(0.60±0.08). Immunohistochemistry study showed caspase-3 protein was located in cytoplasm and nuclei of airway epithelial cells,alveolar epithelial cells and macrophage in hyperoxia mice. The expression of caspase-3 protein in airway epithelium significantly increased at 24 h of hyperoxia compared with their control group(41.62±3.46 verse 15.86±1.84),the expression level was highest at 72 h of hyperoxia (55.24±6.80). Conclusions Both apoptosis and necrosis contribute to cell death during hyperoxia. Apoptosis plays an important role in alveolar damage and cell death from hyperoxia.
出处
《中华结核和呼吸杂志》
CAS
CSCD
北大核心
2004年第7期465-468,共4页
Chinese Journal of Tuberculosis and Respiratory Diseases
