Department of Pediatrics, Affiliated Hospital of Jiangsu University, Zhenjiang, 212000, China.
Department of Pediatrics, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
BMC Pulm Med. 2019 Aug 6;19(1):142. doi: 10.1186/s12890-019-0911-x.
This study aims to investigate the effects of CCAAT/enhancer binding protein alpha (C/EBPα) overexpression on cell proliferation, apoptosis and surfactant protein-C(SP-C) in alveolar epithelial type II (AEC II) cells after exposure to hyperoxia.
pcDNA3.1(+)-C/EBPα plasmid or air-empty vector were transfected into AEC II cells with or without hyperoxia. AEC II cells were divided into air group, air+pcDNA3.1-C/EBPα group, air-empty vector group, hyperoxia group, hyperoxia+pcDNA3.1-C/EBPα group, and hyperoxia-empty vector group. Cell proliferation was analyzed using Cell Counting Kit-8. The mRNA level and protein expression were measured using PCR and Western blot techniques, respectively. The cell cycle and apoptosis were analyzed using flow cytometry.
After 48 h of post-transfection, significantly higher protein expression of C/EBPα was observed in the C/EBPα transfection group with or without hyperoxia compared to the others (P < 0.05). Compared to the air group, hyperoxia decreased cell proliferation, increased apoptosis, decreased SP-C expression, decreased percentage of cells in G1 phase, and increased percentage of cells in the S and G2 phases (P < 0.05); however, reversed by C/EBPα transfection (P < 0.05). No significant changes were observed in cell proliferation, SP-C expression, and apoptosis rates in the C/EBPα transfection group as compared to the controls air-empty vector group.
C/EBPα overexpression significantly upregulates the expression of SP-C, promotes cell proliferation, and inhibits apoptosis in AEC II cells after exposure to hyperoxia. Hence, this data suggests that C/EBPα overexpression may reverse the damage and exert a protective role in hyperoxia-induced lung injury.
本研究旨在探讨过氧化物酶体增殖物激活受体γ共激活因子 1α（PGC-1α）过表达对高氧暴露后肺泡上皮细胞 II 型（AEC II）细胞增殖、凋亡及表面活性蛋白-C（SP-C）的影响。
将 pcDNA3.1(+)-C/EBPα 质粒或空载质粒转染入 AEC II 细胞，分为常氧组、常氧+pcDNA3.1-C/EBPα 组、空载组、高氧组、高氧+pcDNA3.1-C/EBPα 组和高氧空载组。采用细胞计数试剂盒-8 检测细胞增殖，聚合酶链反应（PCR）和 Western blot 技术分别检测 mRNA 水平和蛋白表达，流式细胞术检测细胞周期和凋亡。
转染 48 h 后，高氧或无高氧时 C/EBPα 转染组 C/EBPα 蛋白表达明显高于其他组（P<0.05）。与常氧组相比，高氧降低细胞增殖，增加细胞凋亡，降低 SP-C 表达，降低 G1 期细胞比例，增加 S 和 G2 期细胞比例（P<0.05），而过表达 C/EBPα 可逆转上述改变（P<0.05）。C/EBPα 转染组与空载组比较，细胞增殖、SP-C 表达和凋亡率无明显变化。
过表达 C/EBPα 可显著上调 SP-C 表达，促进高氧暴露后 AEC II 细胞增殖，抑制细胞凋亡，提示 C/EBPα 过表达可能逆转高氧诱导的肺损伤并发挥保护作用。
