Objective: To investigate the expression of long non-coding RNA NANCI in lung tissues of neonatal mice with hyperoxia-induced lung injury and its regulatory effect on NKX2.1.
Methods: A total of 48 neonatal C57BL/6J mice were randomly divided into an air group and a hyperoxia group, with 24 mice in each group. Each group was further divided into 7-day, 14-day, and 21-day subgroups, with 8 mice in each subgroup. The mice in the air group were fed in the indoor environment (FiO2=21%) and those in the hyperoxia group were fed in a high-oxygen box (oxygen concentration: >95%). The mice were sacrificed at each time point and lung tissue samples were collected. Hematoxylin and eosin staining was used to observe pathological changes in lung tissues. RT-qPCR and Western blot were used to measure the mRNA and protein expression of NANCI and NKX2.1.
Results: The air group had the highest mRNA expression of NANCI and NKX2.1 at 7 days and the same level of mRNA expression at 14 and 21 days. Compared with the air group, the hyperoxia group had significant reductions in the degree of alveolarization and radial alveolar count (RAC) in lung tissues (P<0.05), and in the hyperoxia group, RAC gradually decreased over the time of hyperoxia exposure (P<0.05). The hyperoxia group had significantly lower mRNA and protein expression of NANCI and NKX2.1 than the air group at all time points (P<0.05). In both groups, the relative mRNA and protein expression of NANCI and NKX2.1 gradually decreased over the time of hyperoxia exposure (P<0.05). The expression of NKX2 was positively correlated with that of NANCI (r=0.585, P=0.003), and the expression of NKX2 and NANCI was positively correlated with RAC in the hyperoxia group (r=0.655 and 0.541 respectively, P<0.05).
Conclusions: NANCI may be involved in the development of immature lung tissues. Lung injury is gradually aggravated over the time of hyperoxia exposure. The levels of NANCI and NKX2.1 are associated with the severity of lung injury, suggesting that the NANCI/NKX2.1 target gene signaling pathway might be involved in the development of hyperoxia-induced lung injury in neonatal mice.
目的: 探讨长链非编码RNA NANCI在高氧诱导肺损伤新生小鼠肺组织中的表达变化及对NKX2.的调控作用。
方法: 采用随机分组法将48只C57BL/6J新生小鼠随机分为空气组和高氧组，每组24只，各组再随机分为生后7d组、14d组、21d组，每组8只。空气组置于室内环境（FiO2=21%）中饲养，高氧组置于高氧箱（保持氧浓度>95%）中饲养，在各时间点分别处死两组动物后收集肺组织标本。采用苏木精-伊红染色法观察小鼠肺组织病理变化；采用RT-qPCR及Western blot技术分别检测NANCI、NKX2.1的mRNA和蛋白表达水平。
结果: 空气组新生小鼠肺组织NANCI和NKX2.1的mRNA表达水平7d最高（P < 0.05），14d与21d呈同水平表达。与空气组比较，高氧组肺组织肺泡化程度降低，辐射状肺泡计数（RAC）减少（P < 0.05），且高氧组RAC值随高氧处理时间延长逐渐降低（P < 0.05）。各时间点高氧组NANCI mRNA、NKX2.1mRNA及其蛋白表达水平均低于空气组（P < 0.05），且随高氧处理时间延长逐渐降低（P < 0.05）。NKX2.1与NANCI表达呈正相关（r=0.585，P=0.003）；两者与高氧组RAC水平均呈正相关（分别r=0.655、0.541，P < 0.05）。
结论: NANCI可能主要参与未成熟肺组织发育；肺组织损伤程度随高氧暴露时间的延长逐渐加重，且NANCI及NKX2.1水平与肺损伤程度相关，提示NANCI/NKX2.1靶基因信号通路可能参与新生小鼠高氧肺损伤过程。