Effect of PM2.5 on MicroRNA Expression and Function in Nasal Mucosa of Rats With Allergic Rhinitis

Background Particulate matter 2.5 (PM2.5) refers to particulate matter with aerodynamic equivalent diameter less than or equal to 2.5 µm, which is an important component of air pollution. PM2.5 aggravates allergic rhinitis (AR) and promotes AR nasal mucosa inflammation. Therefore, the influence of PM2.5 inhalation exposure on microRNA (miRNA) expression profiles and function in the nasal mucosa of AR rats was investigated. Methods Female Sprague Dawley rats were distributed randomly to 2 groups: AR model PM2.5 exposure group (ARE group) and AR model PM2.5-unexposed control group (ARC group). The rats of ARE group were made to inhale PM2.5 at a concentration of 200 µg/m 3 , 3 h/day, for 30 days. miRNA expression profiles of the nasal mucosa from both groups were determined using an miRNA gene chip and were verified by quantitative real-time PCR (qRT-PCR). Gene function enrichment analysis was performed using bioinformatics analysis. Results The ARE group revealed 20 significantly differentially expressed miRNAs, including 4 upregulated and 16 downregulated miRNAs (fold change > 1.5 or < 0.66, P < .05). Of these, 9 selected miRNAs were verified by qRT-PCR, and the results of 8 miRNAs were in accordance with the miRNA gene chip results, with highly positive correlation ( r = .8583, P = .0031). Numerous target genes of differentially expressed miRNAs were functionally enriched in high-affinity immunoglobulin E receptor signaling, ErbB signaling, mucin O-glycans biosynthesis, transforming growth factor β signaling, mitogen-activated protein kinase signal transduction, phosphatidylinositol signaling, mucopolysaccharide biosynthesis, mammalian target of rapamycin signaling, T cell receptor signaling, Wnt signaling, chemokine signal transduction, and natural killer cell-mediated cytotoxicity pathways. Conclusions PM2.5 causes significant changes in miRNA expression in the nasal mucosa of AR rats. miRNA plays an important role in regulating PM2.5 effects in AR rat biological behavior and mucosal inflammation. This study provides a theoretical basis for the prevention and treatment of AR from the effects of environmental pollution on the gene regulation mechanism.