ObjectiveTo explore the mechanisms by which microplastic toxicity leads to DNA damage in mouse spermatocytes.MethodsWe randomly divided GC-2 cells into a control group and a polystyrene microplastic (PS) group and then evaluated the DNA fragmentation index (DFI) in these cells via a comet assay. Whole-transcriptome sequencing was performed on the basis of DFI results. GO and KEGG enrichment analyses were based on the results of the entire transcriptome sequencing. At the same time, we also performed q-PCR validation on some significantly expressed genes and drew a toxicological network diagram on PS and mouse spermatocytes.ResultsComet assay results revealed that the intake of PS increased the DFI of mouse spermatocytes. Whole-transcriptome sequencing revealed that 61 circRNAs, 132 lncRNAs, 40 miRNAs, and 140 mRNAs were differentially expressed between the control and PS groups. GO and KEGG analyses revealed some notable enrichment in cellular components, molecular functions, biological processes, and gene expression pathways such as the defense response to viruses, the defense response to symbionts, the RIG-I-like receptor, the NOD-like receptor, and the calcium signaling pathways. Q-PCR and the network analysis revealed that PS affects the DFI of mouse spermatocytes mainly by influencing immune responses.ConclusionPS may damage the sperm DNA and increase the DFI by affecting cellular immunity-related pathways and redox pathways such as the RIG-I-like receptor and NOD-like receptor signaling pathways.
Keywords: DNA fragmentation index; cellular immune network; polystyrene microplastics; reproductive damage; whole-transcriptome sequencing.