MicroRNA‐145 regulates immune cytokines via targeting FSCN1 in Staphylococcus aureus‐induced mastitis in dairy cows

Abstract

Dairy cow mastitis is a detrimental factor in milk quality and food safety. Mastitis generally refers to inflammation caused by infection by pathogenic microorganisms. Our studies in recent years have revealed the role of miRNA regulation in Staphylococcus aureus‐induced mastitis. In the present study, we overexpressed and suppressed miR‐145 to investigate the function of miR‐145 in Mac‐T cells. Flow cytometry, ELISA and EdU staining were used to detect changes in the secretion of several Mac‐T cytokines and in cell proliferation. We found that overexpression of miR‐145 in Mac‐T cells significantly reduced the secretion of IL‐12 and TNF‐α, but increased the secretion of IFN‐γ; the proliferation of bovine mammary epithelial cells was also inhibited. Using quantitative real‐time PCR (qRT‐PCR), Western blotting and luciferase multiplex verification techniques, we found that miR‐145 targeted and regulated FSCN1. Knock‐down of FSCN1 significantly increased the secretion of IL‐12, while the secretion of TNF‐α was significantly downregulated in Mac‐T cells. Upon S. aureus infection of mammary gland tissue, the body initiated inflammatory responses; Bta‐miR‐145 expression was downregulated, which reduced the inhibitory effect on the FSCN1 gene; and upregulation of FSCN1 expression promoted mammary epithelial cell proliferation to allow the recovery of damaged tissue. The results of the present study will aid in understanding the immune mechanism opposing S. aureus infection in dairy cows and will provide a laboratory research basis for the prevention and treatment of mastitis.

Exosomal miR‐145‐5p derived from orthohantavirus‐infected endothelial cells inhibits HTNV infection

“…53 Chen et al revealed that miR-145 modulated immune cytokines by targeting fas-cin1 (FSCN1) in Staphylococcus aureus-induced mastitis in dairy cows. 54 Further studies will be needed to elucidate which signaling targets of miR-145-5p are involved in IFN induction during HTNV infection.…”

RNA-Seq Whole Transcriptome Analysis of Bovine Mammary Epithelial Cells in Response to Intracellular Staphylococcus aureus

“…Previous studies have also shown that Bta-miR-145 expression was downregulated in udder tissues after S. aureus infection, consistent with our research. It was also found that overexpression of Bta-miR-145 significantly inhibited the proliferation of bMECs, and also reduced the secretion of IL-12 and TNF-α, but increased the secretion of IFN-γ (77). Therefore, the down-regulation of Bta-miR-145 is conducive to the production of IL-12 and TNF-α, thus inducing an immune response.…”

Tea Tree Oil Prevents Mastitis-Associated Inflammation in Lipopolysaccharide-Stimulated Bovine Mammary Epithelial Cells

“…When calculating differences in gene expression, we used Htseq-count software to determine the number of gene reads in each sample. The estimate SizeFactors function in the DESeq R package was used to standardize the data, and the nbinomTest function was used to calculate the P-value and fold-change values in the difference comparisons (13). The condition used to screen differentially expressed genes was a P < 0.05 and multiple differences was more than 2 times.…”