Microrna bta-mir-24-3p suppressed galectin-9 expression through tlr4/nf-kbsignaling pathway in lps-stimulated bovine endometrial epithelial cells

Abstract

Endometritis is a major infectious disease affecting dairy development. MicroRNAs are recognized as critical regulators of the innate immune response. However, the role and mechanism of bta-miR-24-3p in the development of endometritis are still unclear. This study aimed to investigate the effect of bta-miR-24-3p on the inflammatory response triggered by lipopolysaccharide (LPS) and to clarify the possible mechanism. LPS-treated bovine endometrial epithelial cells (BEECs) were cultured to investigate the role of bta-miR-24-3p. The expression levels of bta-miR-24-3p were downregulated, and galectin-9 (LGALS9) were measured by quantitative real-time polymerase chain reaction. The LPS-induced inflammatory response was assessed by the elevated secretion of inflammatory cytokines measured by using enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction. Activation of nuclear factor-κB (NF-κB) and TLR4 pathway was assessed by Western blot. The interaction between bta-miR-24-3p and LGALS9 was validated by bioinfor-matics analysis and a luciferase reporter assay. LPS-induction in BEECs with bta-miR-24-3p was overexpressed leads inhibition of pro-inflammatory cytokines, LGALS9 expression, and TLR4/NF-kB pathway deactivation. Knockdown of LGALS9 inhibited the LPS-induced inflammatory response in BEECs. LGALS9 was validated as a target of bta-miR-24-3p. Cloned overexpression of LGALS9 failed to alter the effect of bta-miR-24-3p on the inflammatory response in BEECs. Overall, bta-miR-24-3p attenuated the LPS-induced inflammatory response via targeting LGALS9. The immunotherapeutic stabilisation of bta-miR-24-3p could give a therapeutic option for endometritis and other disorders commonly associated with endometritis, suggesting a novel avenue for endometritis treatment.