Respiratory Department, Hunan Children's Hospital, Changsha, 410007, China.
Respiratory Department, Hunan Children's Hospital, Changsha, 410007, China.
Exp Cell Res. 2024 Feb 15;435(2):113945. doi: 10.1016/j.yexcr.2024.113945. Epub 2024 Jan 28.
Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease among neonates, with increasing morbidity and mortality. This study aims to investigate the effect and mechanism of lysine demethylase 3A (KDM3A) on hyperoxia-induced BPD. Hyperoxia-induced BPD mouse and alveolar epithelial cell models were constructed. The effects of hyperoxia on lung development were evaluated by histological and morphological analysis. The levels of KDM3A, E26 transformation specific-1 (ETS1), H3 lysine 9 dimethylation (H3K9me2), and endoplasmic reticulum (ER) stress-related indexes were quantified by RT-qPCR, Western blot, and IF staining. Cell apoptosis was assessed by flow cytometry and TUNEL staining. Transfection of oe-ETS1, oe-KDM3A, and sh-ETS1 was applied in hyperoxia-induced alveolar epithelial cells to explore the mechanism of the KDM3A/ETS1 axis in hyperoxia-induced apoptosis. KDM3A inhibitor IOX1 was applied to validate the in vivo effect of KDM3A in hyperoxia-induced BPD mice. The results displayed that hyperoxia-induced BPD mice showed reduced body weight, severe destruction of alveolar structure, decreased radial alveolar count (RAC), and increased mean linear intercept (MLI) and mean alveolar diameter (MAD). Further, hyperoxia induction down-regulated ETS1 expression, raised ER stress levels, and increased apoptosis rate in BPD mice and alveolar epithelial cells. However, transfection of oe-ETS1 improved the above changes in hyperoxia-induced alveolar epithelial cells. Moreover, transfection of oe-KDM3A up-regulated ETS1 expression, down-regulated H3K9me2 expression, inhibited ER stress, and reduced apoptosis rate in hyperoxia-induced alveolar epithelial cells. In addition, transfection of sh-ETS1 reversed the inhibitory effect of KDM3A on hyperoxia-induced apoptosis by regulating ER stress. In vivo experiments, KDM3A inhibitor IOX1 intervention further aggravated BPD in newborn mice. In a word, KDM3A alleviated hyperoxia-induced BPD in mice by promoting ETS1 expression.
支气管肺发育不良（BPD）是新生儿最常见的慢性肺部疾病，其发病率和死亡率呈上升趋势。本研究旨在探讨赖氨酸去甲基化酶 3A（KDM3A）对高氧诱导的 BPD 的作用及机制。构建高氧诱导的 BPD 小鼠和肺泡上皮细胞模型。通过组织学和形态学分析评估高氧对肺发育的影响。通过 RT-qPCR、Western blot 和 IF 染色定量检测 KDM3A、E26 转化特异性 1（ETS1）、H3 赖氨酸 9 二甲基化（H3K9me2）和内质网（ER）应激相关指标的水平。通过流式细胞术和 TUNEL 染色评估细胞凋亡。转染 oe-ETS1、oe-KDM3A 和 sh-ETS1 应用于高氧诱导的肺泡上皮细胞中，以探讨 KDM3A/ETS1 轴在高氧诱导细胞凋亡中的作用机制。应用 KDM3A 抑制剂 IOX1 验证 KDM3A 在高氧诱导的 BPD 小鼠体内的作用。结果显示，高氧诱导的 BPD 小鼠体重减轻，肺泡结构严重破坏，肺泡计数减少（RAC），平均线性截距（MLI）和平均肺泡直径（MAD）增加。此外，高氧诱导降低了 BPD 小鼠和肺泡上皮细胞中 ETS1 的表达，增加了 ER 应激水平，并增加了细胞凋亡率。然而，oe-ETS1 的转染改善了高氧诱导的肺泡上皮细胞中的上述变化。此外，oe-KDM3A 的转染上调了 ETS1 的表达，下调了 H3K9me2 的表达，抑制了 ER 应激，减少了高氧诱导的肺泡上皮细胞的凋亡率。此外，sh-ETS1 通过调节 ER 应激逆转了 KDM3A 对高氧诱导凋亡的抑制作用。体内实验中，KDM3A 抑制剂 IOX1 的干预进一步加重了新生小鼠的 BPD。总之，KDM3A 通过促进 ETS1 的表达缓解了高氧诱导的 BPD。
