组蛋白H2AX在高体积分数氧暴露肺泡Ⅱ型上皮细胞中的动态表达及其意义  

Dynamic Expression of H2AX in Alveolar Epithelial Type Ⅱ Cells Exposured to Hyperoxia and Its Significance

作　　者：张慧[1] 富建华[1] 薛辛东[1] 

机构地区：[1]中国医科大学附属盛京医院儿科,沈阳110004

出　　处：《实用儿科临床杂志》2012年第16期1274-1277,共4页Journal of Applied Clinical Pediatrics

基　　金：国家自然科学基金(30872781)

摘　　要：目的研究组蛋白H2AX在高体积分数氧(高氧)暴露肺泡Ⅱ型上皮细胞(AECⅡ)中的动态表达,探讨其在高氧致肺细胞损伤中的作用。方法以原代培养的AECⅡ为研究对象,随机分为高氧组和空气组。在实验开始后6 h、12 h、24 h、48 h收集细胞,运用免疫荧光、Western blot及实时荧光定量PCR技术检测AECⅡ中H2AX的表达规律。结果高氧组H2AX蛋白平均荧光强度在实验开始后6 h、12 h均明显高于空气组(Pa<0.05),24 h与空气组比较差异无统计学意义(P>0.05),48 h明显低于空气组(P<0.05)。高氧组H2AX蛋白平均荧光强度随着高氧暴露时间延长渐下降(F=62.7,P<0.01),空气组无明显变化(F=0.3,P>0.05)。H2AX蛋白相对表达量和H2AX mRNA相对表达量的变化趋势与免疫荧光法结果基本相同,高氧暴露6 h后明显升高,随高氧暴露时间延长逐渐降低(F=126.6、244.4,Pa<0.01)。结论在高氧暴露早期,H2AX表达明显升高,随着高氧暴露时间的延长H2AX逐渐降低,这可能造成AECⅡ中DNA双链断裂修复障碍,导致细胞凋亡和坏死,提示H2AX可能与肺损伤密切相关。Objective To explore the dynamic expression of H2AX in alveolar epithelial type cells Ⅱ （ AEC Ⅱ） exposured to hyperoxia and its role in lung cells damage induced by hyperoxia. Methods Primary culture of AEC Ⅱ from newborn rat within 24 hours, and after ad- herenced, the cells were randomly divided into room air group and hyperoxia group. The cells in 2 groups at 6 h, 12 h ,24 h ,48 h after exposure were collected. The expression of H2AX in AEC Ⅱwas detected by immunofluorescence technique, Western blot and real - time fluorescent quantitative polymerase chain reaction. Results Average intensity of H2AX protein in AEC II of hyperoxia group was significantly higher compared with that in the room air group at the 6 h and 12 h （ Pa 〈 0.05 ）, and there was no statistical difference at the 24 h between 2 groups （ P 〉 0.05 ）, but at the 48 h,it was significantly lower than that in room air group （ P 〈 0.05 ）. In the hyperoxia group, the H2AX average in- tensity was decreased with the time of hyperoxia exposure going on（ F = 62.7, P 〈 0.01 ）. The expression trend of H2AX protein and H2AX mRNA were consisted with the result of average intensity, which were the H2AX protein and gene expression of hyperoxia group increased quickly compared with the room air group, and decreased gradually with the length of time exposure to hyperoxia （ F = 126.6,244.4, Pa 〈 0.01 ）. Conclusions Expression of H2AX in AEC 11 increases in early stage of hyperoxia exposure,which is in favour of the repair of DNA damage. But H2AX gradually decreases as prolonged exposure to hyperoxia ,which may cause DNA double - strand breaks repair disable and result in cell apoptosis or necrosis. H2AX is closely related to the lung injury induced by hyperoxia probably.

关 键 词：H2AX 肺损伤 高氧 肺泡Ⅱ型上皮细胞 

分 类 号：R722.6[医药卫生—儿科]