Department of Children, Beijing Luhe Hospital, Capital Medical University, Beijing, China.
Department of NICU, Senior Department of Pediatrics, the Seventh Medical Center of PLA General Hospital, Beijing, China.
Allergol Immunopathol (Madr). 2023 Mar 1;51(2):191-204. doi: 10.15586/aei.v51i2.710. eCollection 2023.
Bronchopulmonary dysplasia (BPD) is a serious and long-term lung condition commonly observed in premature babies. Sirtuin 3 (SIRT3) has been reported to reduce pulmonary injury and pulmonary fibrosis.
The present study investigated the specific role of SIRT3 in BPD by establishing hyperoxia-induced BPD rat and cell models. Hematoxylin and eosin staining was used to observe pathological changes in lung tissues.
The expression levels of SIRT3 and forkhead box protein O1 (FOXO1), as well as its acetylation levels, were detected in hyperoxia-induced lung tissues and cells by Western blot analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Levels of reactive oxygen species, superoxide dismutase, and malondialdehyde were assessed by using biochemical kits. Following SIRT3 overexpression, the levels of inflammatory cytokines were assessed by RT-qPCR. Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nickend labeling (TUNEL) and Western blot analysis. Upon FOXO1 knockout, cell inflammation, oxidative stress and apoptosis were evaluated again.
Compared to the control group, the SIRT3 and FOXO1 expression levels were decreased and the FOXO1 acetylation levels were increased in hyperoxia-induced lung tissues and cells. In addition, SIRT3 reduced hyperoxia-induced inflammation, oxidative stress, and apoptosis in A549 cells, and inhibited FOXO1 acetylation to activate FOXO1. However, FOXO1 knockdown reversed the effects of SIRT3 overexpression in hyperoxia-induced A549 cells.
SIRT3 relieved alveolar epithelial cell damage caused by BPD via deacetylation of FOXO1, suggesting that SIRT3 could be a therapeutic target in BPD.
支气管肺发育不良（BPD）是一种常见于早产儿的严重且长期的肺部疾病。Sirtuin 3（SIRT3）已被报道可减轻肺损伤和肺纤维化。
本研究通过建立高氧诱导的 BPD 大鼠和细胞模型，探讨 SIRT3 在 BPD 中的具体作用。苏木精-伊红染色观察肺组织的病理变化。
采用 Western blot 分析和逆转录定量聚合酶链反应（RT-qPCR）检测高氧诱导的肺组织和细胞中 SIRT3 和叉头框蛋白 O1（FOXO1）的表达水平及其乙酰化水平。采用生化试剂盒评估活性氧、超氧化物歧化酶和丙二醛的水平。过表达 SIRT3 后，通过 RT-qPCR 评估炎症细胞因子的水平。采用末端脱氧核苷酸转移酶 dUTP 缺口末端标记（TUNEL）和 Western blot 分析检测细胞凋亡。敲除 FOXO1 后，再次评估细胞炎症、氧化应激和细胞凋亡。
与对照组相比，高氧诱导的肺组织和细胞中 SIRT3 和 FOXO1 的表达水平降低，FOXO1 的乙酰化水平升高。此外，SIRT3 降低了 A549 细胞中高氧诱导的炎症、氧化应激和细胞凋亡，并抑制了 FOXO1 乙酰化以激活 FOXO1。然而，FOXO1 敲低逆转了 SIRT3 过表达在高氧诱导的 A549 细胞中的作用。
SIRT3 通过去乙酰化 FOXO1 缓解 BPD 引起的肺泡上皮细胞损伤，提示 SIRT3 可能是 BPD 的治疗靶点。
