N6-methyladenosine mediates Nrf2 protein expression involved in PM2.5-induced pulmonary fibrosis.
N6-methyladenosine mediates Nrf2 protein expression involved in PM2.5-induced pulmonary fibrosis.
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DOI：
10.1016/j.ecoenv.2023.114755
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发表时间：
2023-03
影响因子：
6.8
通讯作者：
Ding Ji;Chenxi Hu;Jie Ning;Xiaoling Ying;Haiqing Zhang;Bo Zhang;Bixia Liu;Qingping Liu
中科院分区：
文献类型：
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作者：
Ding Ji;Chenxi Hu;Jie Ning;Xiaoling Ying;Haiqing Zhang;Bo Zhang;Bixia Liu;Qingping Liu
据报道，空气动力学直径<2.5 µm的颗粒物（PM2.5）可诱导上皮-间充质转化（EMT）和细胞外基质（ECM）相关的肺纤维化（PF）。转录因子Nrf 2通过拮抗氧化应激减轻PM2.5诱导的PF。N6-甲基腺苷（m6 A）修饰在应激反应中起着重要作用。然而，m6 A修饰对Nrf 2介导的防御PM2.5诱导的PF的机制的影响仍然未知。本研究通过建立过滤空气（FA）、未过滤空气（UA）和浓缩PM2. 5空气（CA）组小鼠模型以及0、50和100 μg/mL PM2. 5处理的16 HBE细胞模型，探讨Nrf 2 mRNA m6 A甲基化在PM2. 5诱导肺纤维化中的作用及其分子机制。通过组织病理学分析、免疫组化染色和Western blotting检测小鼠肺纤维化程度和纤维化指标。通过m6 A-甲基化RNA免疫沉淀（MeRIP）、RNA免疫沉淀（RIP）、qRT-PCR和基于T3连接酶的PCR证实了m6 A修饰Nrf 2的分子机制。我们的数据表明，PM2.5暴露16周可诱导肺纤维化并激活Nrf 2信号通路。PM2.5在体内和体外处理后，m6 A甲基转移酶胃L3表达上调。此外，在PM2.5暴露后，胃L3介导了Nrf 2 mRNA的m6 A修饰，并促进了小鼠和16 HBE细胞中Nrf 2的翻译。从机制上讲，在PM2.5处理的16 HBE细胞中鉴定了Nrf 2 mRNA的三个m6 A修饰位点（1317、1376和935;相对于3 'UTR的第一个核苷酸编号）。此外，m6 A结合蛋白YTHDF 1/IGF 2BP 1通过结合Nrf 2 mRNA的m6 A残基促进Nrf 2翻译。我们的研究结果揭示了m6 A介导的Nrf 2信号通路对抗氧化应激的机制，从而影响PM2.5诱导的PF的发展。
It has been reported that particulate matter with an aerodynamic diameter of <2.5 µm (PM2.5) could induce epithelial–mesenchymal transition (EMT)- and extracellular matrix (ECM)-related pulmonary fibrosis (PF). The transcription factor Nrf2 alleviated PM2.5-induced PF by antagonizing oxidative stress. The N6-methyladenosine (m6A) modification plays a significant role in the stress response. However, the effect of m6A modification on the mechanisms of Nrf2-mediated defense against PM2.5-induced PF remained unknown. Here, we explored the role and the underlying molecular mechanisms of m6A methylation of Nrf2 mRNA in PM2.5-induced PF. We established filtered air (FA), unfiltered air (UA), and concentrated PM2.5 air (CA) group mice model and 0, 50, and 100 μg/mL PM2.5-treated 16HBE cell models. The extent of lung fibrosis in mice and fibrosis indicators were detected by histopathological analysis, immunohistochemical staining and western blotting. The molecular mechanism of m6A-modified Nrf2 was demonstrated by m6A-methylated RNA immunoprecipitation (MeRIP), RNA immunoprecipitation (RIP), qRT-PCR and T3 ligase-based PCR. Our data showed that PM2.5 exposure for 16 weeks could induce pulmonary fibrosis and activate Nrf2 signaling pathway. m6A methyltransferase METTL3 was upregulated after PM2.5 treatment invivoand invitro. Moreover, METTL3 mediated m6A modification of Nrf2 mRNA and promoted Nrf2 translation in mice and 16HBE cells after PM2.5 exposure. Mechanistically, three m6A-modified sites (1317, 1376 and 935; numbered relative to the first nucleotide of 3’UTR) of Nrf2 mRNA were identified in PM2.5-treatment 16HBE cells. Furthermore, the m6A binding proteins YTHDF1/IGF2BP1 promoted Nrf2 translation by binding to m6A residues of Nrf2 mRNA. Our results revealed the mechanism of m6A mediated Nrf2 signaling pathway against oxidative stress, which affected the development of PM2.5-induced PF.