PM2.5介导m6A甲基化调控STC2增强细胞自噬促进哮喘气道上皮间质转化的机制研究

流行病学表明PM2.5加重哮喘病程和发病率，但相关机制尚不完善。前期PM2.5暴露模型中，发现m6A甲基化酶METTL3表达增加，总m6A修饰升高。结合m6A和转录组测序筛选到关键基因STC2，其m6A修饰与表达量均受PM2.5诱导。同时，PM2.5诱导的上皮间质转化（EMT）与STC2激活的细胞自噬密切相关。为进一步证实PM2.5介导m6A修饰通过METTL3调控STC2，从而增强细胞自噬，诱导气道EMT发生，本项目拟以METTL3作为切入点，采用RNA免疫共沉淀、m6A-IP-qPCR和免疫印迹等方法分析m6A修饰对STC2的调节作用；采用分子细胞学方法并结合实验动物模型，研究STC2在激活细胞自噬过程中的潜在作用与调控机制。通过本课题的实施有助于阐明PM2.5暴露下，m6A甲基化、细胞自噬与哮喘急性发作之间的关系；发现潜在分子治疗靶点，并为相关靶点应用于临床转化奠定医学理论基础。

Epidemiological evidences suggested that PM2.5 aggravated the course and incidence rate of asthma, but the mechanism is not fully uncovered. Our previous studies revealed that the expression of m6A methylase METTL3 and the total level of m6A modification were increased after PM2.5 exposure. In addition, STC2, the key gene regulated by PM2.5, was screened out by using MeRIP-seq combined with RNA-seq. Both of the m6A enrichment and expression of STC2 were induced by PM2.5. Meanwhile, we found that PM2.5-induced epithelial mesenchymal transition (EMT) was mediated by STC2 through activation of autophage. To further confirm that PM2.5 induced EMT by STC2-dependent autophage through m6A methylation mediated by METTL3. We will apply RNA immunoprecipitation, m6A-IP-qPCR, Westernblot to analyze the regulatory effect of m6A modification on STC2; explore the potential role and regulatory mechanism of STC2-activated autophagy in promoting EMT both in vivo and in vitro. According to the implementation of this project, it would be helpful to clarify the relationship among m6A methylation, autophagy and asthma under PM2.5 exposure. As a result, we could find the potential molecular therapeutic targets and establish the theoretical evidence for the application of targets in clinical transformation.