背景:证据表明,暴露于PM2.5会增加呼吸系统疾病的住院率和死亡率。然而,与PM2.5诱导的肺功能障碍相关的潜在生物标志物和靶标尚未完全发现.
方法:基因本体论(GO),应用了京都基因和基因组百科全书(KEGG)和HALLMARK对RNA-seq数据(用PM2.5处理的Beas-2B细胞)的富集分析。进行基因集富集分析(GSEA)以鉴定与自噬相关的生物学过程。从基因表达综合(GEO)数据库下载三个基因表达谱数据集(GSE158954、GSE155616和GSE182199)以鉴定潜在靶标。构建了暴露于PM2.5的小鼠。实时qPCR,siRNA转染,westernblot,免疫荧光,和病理染色用于体外和体内研究的验证。
结果:GO,基于RNA-seq数据的KEGG和HALLMARK富集显示差异表达基因(DEGs)与自噬样溶酶体和巨自噬相关。GSEA分析显示,与对照组相比,PM2.5与自噬相关的生物过程呈正相关。维恩图表明,在我们的数据以及这三个数据集(GSE158954,GSE155616和GSE182199)中,IL24在PM2.5暴露后被上调。与分析一致,在体内和体外验证了PM2.5对自噬的激活。在暴露于PM2.5的小鼠中,观察肺部病理变化,包括气道炎症和粘液分泌。关键基因的mRNA和蛋白质水平,IL24显著增加。此外,巴弗洛霉素A1,自噬抑制剂,抑制自噬,改善PM2.5所致的肺损伤。此外,IL24的下调降低了自噬活性。同时,IL24受mTOR信号调节。
结论:总之,我们发现了在PM2.5暴露期间IL24与自噬之间的潜在关系。IL24可能是PM2.5通过调节自噬导致肺功能障碍的新的潜在生物标志物或治疗靶点。
BACKGROUND: Evidence suggests that exposure to PM2.5 increased hospitalization and mortality rates of respiratory diseases. However, the potential biomarkers and targets associated with PM2.5-induced lung dysfunction are not fully discovered.
METHODS: Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and HALLMARK enrichment analysis of the RNA-seq data (Beas-2B cells treated with PM2.5) were applied. Gene set enrichment analysis (GSEA) was performed to identify the biological processes correlated with autophagy. Three gene expression profile datasets (GSE158954, GSE155616 and GSE182199) were downloaded from the Gene Expression Omnibus (GEO) database to identify the potential targets. PM2.5-exposed mice were constructed. Real-time qPCR, siRNA transfection, western blot, immunofluorescence, and pathological staining were applied for validation both in vitro and in vivo studies.
RESULTS: GO, KEGG and HALLMARK enrichment based on RNA-seq data showed that the differentially expressed genes (DEGs) were associated with autophagy like lysosome and macroautophagy. GSEA analysis revealed that PM2.5 was positively correlated with autophagy-related biological processes compared with control group. Venn diagrams identified
IL24 was upregulated in our data as well as in these three datasets (GSE158954, GSE155616 and GSE182199) after PM2.5 exposure. Consistent with the analysis, activation of autophagy by PM2.5 was validated in vivo and in vitro. In PM2.5-exposed mice, lung pathological changes were observed, including airway inflammation and mucus secretion. The mRNA and protein levels of the key gene,
IL24, were significantly increased. Moreover, Bafilomycin A1, the inhibitor of autophagy, inhibited the autophagy and ameliorated lung injury induced by PM2.5. Furthermore, downregulation of
IL24 decreased autophagy activity. Meanwhile,
IL24 was regulated by mTOR signaling.
CONCLUSIONS: In summary, we discovered a potential relationship between
IL24 and autophagy during PM2.5 exposure. IL24 might be a novel potential biomarker or therapeutic target in PM2.5 caused lung dysfunction through regulation of autophagy.