Huang Dan, Tang Bin, Li Qiugen, Tong Bo, Liu Na
Department of Anesthesiology, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, Jiangxi Province, China.
Department of Pulmonary and Critical Care Medicine, Jiangxi Provincial People's Hospital (The First Affiliated Hospital of Nanchang Medical College), Nanchang 330038, Jiangxi Province, China.
Transl Res. 2025 May;279:1-15. doi: 10.1016/j.trsl.2025.03.002. Epub 2025 Mar 12.
Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. The DNA methyltransferase DNMT3a has been implicated in COPD, however its upstream regulation and downstream mechanisms remain unclear.
Relative mRNA and protein levels of indicated genes in lung tissues and dendritic cells (DCs) were tested via qRT-PCR and western blot, respectively. Cellular distribution of DNMT3a in DCs was determined by immunofluorescence staining. COPD mouse model was established by exposing mice to cigarette smoke (CS) via nose. The Th17/Treg cell ratio was examined using flow cytometry. Production of indicated cytokines was assessed by corresponding commercial ELISA kit. Interplay between DACH1 and c-Jun was verified by Co-immunoprecipitation, ChIP and luciferase reporter assays. Methylation level of DACH1 was tested by methylation specific PCR.
DNMT3a expression was upregulated and negatively correlated with lung function in COPD patients. CS exposure increased pulmonary DNMT3a in mice. DNMT3a was predominantly expressed in the nucleus and CS exposure promoted its translocation to cytoplasm. RNA binding protein ELAVL1 upregulated DNMT3a expression, induced its nuclear translocation and increased its enzyme activity. DNMT3a promoted Th17 differentiation while inhibited Treg differentiation. DNMT3a methylated DACH1 and inhibited its expression, resulting in c-Jun pathway activation. In vivo DNMT3a knockdown ameliorated lung injury and Th17/Treg imbalance in COPD mice.
This study suggests that ELAVL1 regulates DNMT3a expression and nuclear translocation to modulate dendritic cell function and Th17/Treg balance through DACH1/c-Jun pathway in COPD.
慢性阻塞性肺疾病（COPD）是全球发病和死亡的主要原因。DNA甲基转移酶DNMT3a与COPD有关，但其上游调控和下游机制仍不清楚。
分别通过qRT-PCR和蛋白质印迹法检测肺组织和树突状细胞（DCs）中所示基因的相对mRNA和蛋白质水平。通过免疫荧光染色确定DNMT3a在DCs中的细胞分布。通过经鼻将小鼠暴露于香烟烟雾（CS）建立COPD小鼠模型。使用流式细胞术检测Th17/Treg细胞比例。通过相应的商业ELISA试剂盒评估所示细胞因子的产生。通过免疫共沉淀、染色质免疫沉淀和荧光素酶报告基因测定验证DACH1和c-Jun之间的相互作用。通过甲基化特异性PCR检测DACH1的甲基化水平。
COPD患者中DNMT3a表达上调且与肺功能呈负相关。CS暴露增加了小鼠肺组织中的DNMT3a。DNMT3a主要在细胞核中表达，CS暴露促进其向细胞质的转位。RNA结合蛋白ELAVL1上调DNMT3a表达，诱导其核转位并增加其酶活性。DNMT3a促进Th17分化而抑制Treg分化。DNMT3a使DACH1甲基化并抑制其表达，导致c-Jun途径激活。在体内敲低DNMT3a可改善COPD小鼠的肺损伤和Th17/Treg失衡。
本研究表明，ELAVL1通过DACH1/c-Jun途径调节DNMT3a的表达和核转位，以调节COPD中树突状细胞功能和Th17/Treg平衡。
