Objective This study aims to investigate the role of miR-193a-5p in bovine mastitis by constructing an inflammatory response model of lipopolysaccharide (LPS)-induced bovine mammary epithelial cells line (MAC-T).

Method The miR-193a-5p expression level in LPS-induced MAC-T cells inflammatory response model was detected. By overexpressing miR-193a-5p in MAC-T cells, qPCR, CCK-8 and EdU assays were used to examine expression changes of inflammatory factors, proliferation- and apoptosis-related genes, as well as cell viability and proliferation. Bioinformatics methods were employed to predict candidate target genes of miR-193a-5p, and GO and KEGG analyses were conducted to reveal its potential mechanisms of action.

Result The miR-193a-5p expression levels were significantly downregulated at 3, 6 and 12 h after LPS induction in MAC-T cells (P<0.01). Overexpression of miR-193a-5p promoted the expressions of inflammatory cell factors (IL-1β and IL-8) and apoptosis-related gene (CASP9), and inhibited the expression of proliferation-related genes (BCL2 and PCNA). Furthermore, miR-193a-5p overexpression suppressed cell viability and proliferation. A total of 44 candidate target genes of miR-193a-5p were predicted. These genes were enriched in pathways including ribosome biogenesis in eukaryotes, adherens junction, NF-κB signaling pathway, Wnt signaling pathway, and Alzheimer disease, and were primarily involved in biological processes such as the regulation of cell differentiation and regulation of cytokine production.

Conclusion The miR-193a-5p expression is downregulated in LPS-induced MAC-T cells. Overexpression of miR-193a-5p potentially promotes inflammatory responses, inhibits proliferation, and induces apoptosis through the NF-κB and Wnt signaling pathways, suggesting its regulatory role in the bovine mastitis pathogenesis.