高浓度氧对早产鼠II型肺泡上皮细胞增殖和细胞周期的影响

目的探讨高浓度氧(简称高氧)对早产鼠II型肺泡上皮细胞(AECII)增殖和细胞周期的影响。方法原代培养早产大鼠AECII,建立高氧细胞损伤模型。血球计数板计数法对培养细胞计数,台盼蓝拒染法检测细胞活力,流式细胞术检测细胞周期和Ki67表达。结果空气组AECII在培养后其数目不断增加,高氧组给氧后48和72h,细胞数目减少、细胞活力降低。高氧使G0/G1期细胞比例显著增多,S和G2/M期细胞比例明显减少。高氧组给氧后24、48及72h,Ki67阳性细胞的表达率及荧光指数较同时间点空气组均明显降低(P<0.05或P<0.01)。结论原代培养的早产大鼠AECII暴露在高氧环境中发生G1期阻滞,Ki67表达减少,细胞增殖受抑,这种增殖受抑与早产儿慢性肺损伤的发生密切相关。

Effects of hyperoxia on the proliferation and cell cycle of type II alveolar epithelial cell from premature rat

Objective To investigate the effects of hyperoxia on the proliferation and cell cycle of type II alveolar epithelial cell (AEC II) in premature rat.Methods AEC IIs from premature rat lung were cultured primarily and a hyperoxia-damage cell model was established.Cell number was counted with a hemacytometer.Cell viability was determined by typan blue dye exclusion method.Flow cytometry was used as assays for the cell cycle and Ki67 expression.Results Cell number in room air group increased gradually.After exposed to hyperoxia for 48 and 72?h,cell number reduced and cell viability was decreased.Hyperoxia increased the percentage of cells in G1 and decreased the percentage in S and G2/M phases of the cell cycle.Compared with the room air group,the expression rate of Ki67 in cells and fluorescence index (FI) decreased markedly at 3 time points of hyperoxia exposure for 24,48 and 72 hours(P<0.05 or P<0.01).Conclusion Hyperoxia inhibited proliferation of primarily cultured AEC II from premature rat lung in G1 phase of the cell cycle and decreased the expression rate of Ki67,and this proliferation arrest may be associated with the pathogenesis of chronic lung disease of premature infants.