肺泡上皮细胞在高氧急性肺损伤中的作用研究

On Role of Alveolar Epithelial Cells in Hyperoxic Acute Lung Injury

目的:观察新生小鼠肺组织甲状腺转录因子[TTF-1]及肺表面活性物质蛋白B[SP-B]的表达,探讨高氧急性肺损伤[HALI]可能存在的损伤机制.方法:新生1d的C57BL/6小鼠30只,随机分为:高氧暴露组及空气对照组,每组15只.高浓度氧暴露72h建立ALI小鼠模型,各组于24,48及72h随机取5只小鼠肺组织标本,测定肺湿/干重(W/D)比值、观察肺组织形态学变化并进行病理评分及肺泡计数(RAC),荧光定量PCR法及免疫荧光标记法检测各组各实验点TTF-1,SP-BmRNA及蛋白的表达情况.结果:与空气对照组比较,高氧暴露48h时,肺组织出现肺泡间质细胞数量增多及肺水肿等HALI的表现;W/D比值及病理评分显著升高(P<0.05);RAC显著减少(P<0.05).高氧暴露72h时,TTF-1,SP-B mRNA及蛋白表达较空气对照组下调(P<0.05).结论:高浓度氧暴露能导致ALI,肺泡上皮细胞的损伤在HALI发生进程中可能发挥重要作用.

Observed the expressions of thyroid transcription factor-1（TTF-1）and surfactant protein B （SP-B） in the lungs of newborn mice with exposed to hyperoxia in order to explain the possible pathogenesis of hyperoxia acute lung injury（HALI）. Totally 30 postnatal day 1 mice, which were randomly divided into hyperoxia exposed group and air control group（ n =15） respectively. hyperoxia exposed for 72 hours induce the HALI.assessed the wet/dry weight（W/D）ratio,observed the changes of lung pathology , injury score and radical alveolar counts . The protein and mRNA expressions of thyroid transcription factor-1（TTF-1）and surfactant protein B （SP-B） were detected by immunofluorescence and real-time PCR after 24,48and72 hours, respectively. Contrasted the air control group, lung tissue gradually showed increased interstitial cell and pulmonary edema at hyperoxia exposed for 48 hours.and W/D ratio and injury scores of 48 hours（all P 〈0.05） were noted increased . RAC were decreased significantily （ P 〈0.05）. The mRNA and protein expression of TTF-1 and SP-B in lung tissue were decreased markedly at 72 hours of hyperoxia exposed group compared with the air control group. In newborn mice hyperoxia exposed can induced lung injury , and disrupts pulmonary epithelial may be plays an very important role in the development of HALI .