Fine particulate matter (PM2.5) induces microRNA-192–5p causing glomerular damage

To unravel changes in gene expression due to exposure to PM2.5, we performed bulk RNA-seq analyses of zebrafish larvae exposed to PM2.5 and controls. Among others, PM2.5 increased oxoglutarate alpha-ketoglutarate receptor 1a, nitric oxide synthase, arachidonate 5-lipoxygenase b, immunity-related GTPase family e1, sulfotransferase family 5A, and macrophage expressed 1. NADPH oxidase organizer 1a and NADPH oxidase 1 were upregulated due to PM2.5 exposure. Furthermore, protein tyrosine/serine/threonine phosphatase activity was decreased after exposure to PM2.5. GESA analysis showed that genes involved in proteasome complex formation, inflammatory and immune response, leucocyte-mediated cytotoxicity, peptidase activator activity protein folding, and apoptotic signaling were upregulated after exposure to PM2.5. These results indicate that PM2.5 exposure caused the activation of immune-inflammatory and oxidative stress pathways and lipid and metabolic dysregulation. Overall design: Zebrafish were mated at 28.5°C, and larvae grew in standard E3 solution. Zebrafish larvae were exposed to 1.2 × 10^7 smog particles from 72 hours post-fertilization (hpf) till 120 hpf. Untreated zebrafish larvae served as controls. RNA was isolated from 5-7 zebrafish larvae in each group. RNA from whole zebrafish was isolated using the ReliaPrep™ RNA Miniprep System (Promega, Madison, WI, USA), based on the manufacturer's protocol. The RNA quality of each sample was evaluated with a bioanalyzer, and only samples with an RNA Integrity Number (RIN) greater than 7.8 were selected for sequencing. Libraries were prepared following Novogene's in-house protocol. Sequencing was carried out using paired-end reads of 150 base pairs on an Illumina Novaseq 6000 (Illumina, USA), yielding an average of 20 million reads per sample.