The alterations of miRNA and mRNA expression profile and their integration analysis induced by silica nanoparticles...

Air pollution and the application of Silica nanoparticles (SiNPs) have increased the risk of human exposure to SiNPs. SiNPs are known to induce cytotoxicity in spermatocyte cells (GC-2spd cells) of mice and male reproductive system damage. However, the expression profiles of miRNA and mRNA and the molecular mechanism of miRNA-mRNA integration in reproductive toxicity induced by SiNPs in GC-2spd cells are still unclear. Therefore, GC-2spd cells were divided into 0 μg/mL and 5 μg/mL SiNPs groups, and the cells were collected and analyzed after passaging for 30 generations using miRNA microarray and Illumina high-throughput sequencing (Illumina HiSeq) for the integrated analysis of miRNA and mRNA expression. Both miRNA Microarray and Illumina Hiseq identified 15 significant differentially expressed miRNAs and 1648 significant differentially expressed mRNAs. Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and miRNA-gene-pathway-network analysis revealed 15 significant differentially expressed miRNAs that could regulate the DNA replication and the fatty acid metabolism, respectively. Furthermore, the mRNA-mRNA regulatory network analysis revealed that Pkfl (phosphofructokinase, liver, B-type) and DHCR24 (24-dehydrocholesterol reductase) were highly expressed, but also affected DNA replication and fatty acid metabolism in SiNPs-treated GC-2spd cells. Additionally, miRNA-mRNA integration analysis revealed that miRNA-138-1-3p might have a regulatory relationship with fatty acid metabolism and DNA replication. It is confirmed that SiNPs could decrease the expression of 10 miRNAs and increase the expression of 5 miRNAs. These findings suggest that the cytotoxicity of GC-2spd cells induced by SiNPs depends on the deregulation of multiple miRNAs, which regulate the DNA replication and fatty acid metabolism. Our results are the first to establish an integrated analysis of miRNA-mRNA interactions and mRNA-mRNA and defines multiple pathways involved in SiNPs-treated GC-2spd cells.