Dimethyl itaconate protects against lipopolysaccharide-induced endometritis by inhibition of TLR4/NF-κB and activation of Nrf2/HO-1 signaling pathway in mice

OBJECTIVE(S): Endometritis is the inflammation of the uterine lining that is associated with infertility. It affects milk production and reproductive performance and leads to huge economic losses in dairy cows. Dimethyl itaconate (DI), a promising chemical agent, has recently been proved to have multiple health-promoting effects. However, the effects of DI on endometritis remain to be unknown. MATERIALS AND METHODS: In this study, we assessed the anti-inflammatory effects of DI on Lipopolysaccharide (LPS)-induced endometritis in mice. The endometritis was induced by LPS treatment for 24 hr, and DI was given 24 hr before induction of LPS. RESULTS: As a result, DI administered mice significantly suffered less impairment of uterine tissue and less recruitment of inflammatory cells than LPS administered mice. In addition, DI markedly inhibited uterine myeloperoxidase (MPO) activity and pro-inflammatory cytokines of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) induced by LPS. Moreover, LPS-induced toll-like receptor 4/ nuclear factor-kappa B (TLR4/NF-κB) activation was suppressed by DI. In addition, the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase (HO-1) were upregulated by DI. CONCLUSION: These findings suggest that DI has anti-inflammatory functions in the LPS-induced mice and may be a therapeutic agent against endometritis.