摘要目的 探讨高体积分数氧(高氧)暴露对早产新生SD大鼠肺组织中微小RNA 125b(miR-125)和肿瘤坏死因子-α(TN F-α)、白细胞介素6(IL-6)表达水平的影响.方法 将80只早产SD大鼠出生24 h按随机数字表法分为空气组和高氧组.将高氧组早产大鼠暴露于氧箱中,调节氧流量1～3 L/min,氧体积分数维持(800±50) mL/L;空气组置于同一室内常压空气中,氧体积分数为210 mL/L,饲养条件相同.分别于不同时间点(1、4、7、10、14 d)提取各组及各个时间点早产SD大鼠肺组织标本,采用苏木精-伊红(HE)染色法观察肺组织病理变化,应用反转录聚合酶链反应(RT-PCR)及酶联免疫吸附试验(ELISA)检测不同时间点高氧暴露肺损伤肺组织中miR-125b、TNF-α及IL-6的表达情况.结果 与空气组相比,高氧组早产大鼠肺组织miR-125b的表达自第1天后缓慢增加,第10天达到最高值(2.554±0.323),第14天表达量略有下降(2.329±0.263),各时间点组间比较差异均有统计学意义(均P＜0.05);TNF-o自第7天开始增高[(78.55±39.53) ng/L],且在第10天显著增高[(80.16±11.24) ng/L],差异有统计学意义(P＜0.05);IL-6自第7天起开始增高[(45.44±31.94) ng/L],在第10天显著增高[(90.38±8.24) ng/L],差异均有统计学意义(均P＜0.05).高氧组中,miR-125b与TNF-α不存在显著线性相关(r=0.132,P＞0.05),miR-125b与IL-6呈正相关(r=0.439,P＜0.05).结论 miR-125b与TNF-α、IL-6均参与高氧暴露所致支气管肺发育不良的发病过程,IL-6可能为其关键因子.

abstractsObjective To observe the expression of microRNA-125b (miR-125),tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in premature rats exposed to hyperoxia.Methods Eighty 1-day old Sprague Dawley (SD) rats were randomly divided into an air group and a hyperoxia group.The rats in the hyperoxia group were continuously exposed to oxygen chamber for 1-3 L/min,oxygen volume fraction was maintained at (800 ± 50) mL/L,and the rats in air group were placed in the same room with the oxygen volume fraction at 210 mL/L.The feeding conditions were same in 2 groups.Lung tissues of premature rats were extracted at different time (1,4,7,10,14days).The pathologic changes in the lung tissues were observed by hematoxylin-eosin (HE) staining.The levels of miR-125b and TNF-α t,IL-6 in lung tissues were detected by reverse transcription polymerase chain reaction (qRT-PCT) and enzyme-linked immunosorbent assay (ELISA).Results Compared with the air group,miR-125b in the hyperoxia group increased slowly after day 1,reached the highest in day 10 (2.554 ± 0.323),and the relative expression in day 14 decreased slightly(2.329 ±0.263),and there were significant differences between 2 groups at different time (all P ＜ 0.05);in particular TNF-α level increased in day 7 [(78.55 ± 39.53) ng/L],and reached the peak at day 10 [(80.16 ± 11.24) ng/L],and there was a significant difference(P ＜0.05);IL-6 levels increased at day 7 [(45.44 ±31.94) ng/L],and reached the peak at day 10 [(90.38 ±8.24) ng/L],and there was a significant difference(P ＜ 0.05).There was a no significant correlation between miR-125b and TNF-α in the hyperoxia groups (r =0.132,P ＞ 0.05),but there was significant correlation between miR-125b and IL-6 in hyperoxia groups (r =0.439,P ＜ 0.05).Conclusions The levels of miR-125b,TNF-α and IL-6 are involved in the pathological process of bronchopulmonary dysplasia induced by hyperoxia,and IL-6 may be the key factor for miR-125b.