Reproduction Abstracts

Introduction: Endometritis is one of the most common reproductive diseases affected postpartum bovine uteri. Lipopolysaccharide (LPS) from Gram-negative bacteria is recognized by Toll-like receptor 4 (TLR4). Binding of LPS and TLR4 mediates the expression of proinflammatory cytokines and chemokines. The excessive inflammatory responses could be involved with endometrial damage.TLR4 antagonist Rhodobacter sphaeroides LPS (RsLPS), is a potent antagonist of LPS from pathogenic bacteria. This study aimed to assess the effect of TLR4 antagonist RsLPS on the responses of bovine endometrium.

Methods: Primary cultures of mixed endometrial epithelial and stromal cells were challenged with LPS (100 ng/ml) after treated with and without TLR4 antagonist (5000 ng/ml). The mRNA expression of TLR4, TNFα and CXCL8 (also known as IL8) were investigated using quantitative real-time PCR.

Results and discussion: As expected, LPS up-regulated the expression of TNFα and CXCL8 (P<0.01). Endometrial cells treated LPS following the exposure of RsLPS showed significantly increased TLR4 expression (P<0.05). On the other hand, LPS did not significantly enhanced mRNA expression of TNFα and CXCL8 (P>0.05) in the endometrial cells pre-treated with RsLPS. Our findings suggested that the TLR4 antagonist may act as a potential treatment of clinical endometritis by mainly competition with endotoxin LPS for the same binding site on extracellular protein of TLR4 complex.