Regulatory roles of PGE2 in LPS-induced tissue damage in bovine endometrial explants

Bovine endometritis is the most common uterine disease following parturition. The role of prostaglandin E₂ (PGE₂) in regulating normal physiological function in the bovine endometrium has been clearly established. Although PGE₂ accumulation is observed in multiple inflammatory diseases, such as endometritis, its association with pathogen-induced inflammatory damage in the endometrium is unclear. To clarify the role of PGE₂ in lipopolysaccharide (LPS)-induced endometritis in cultured bovine endometrial explants, the levels of PGE₂ secretion, prostaglandin synthetases, pro-inflammatory factors, and damage-associated molecular patterns (DAMPs) were evaluated in the present study. Significant PGE₂ accumulation in response to LPS stimulation, up-regulation of prostaglandin-endoperoxide synthase-2 (PTGS-2), microsomal prostaglandin E synthase-1 (mPGES-1), pro-inflammatory factors including interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and induced nitric oxide synthase (iNOS)/nitric oxide (NO) and DAMPs including hyaluronan binding protein 1 (HABP1) and high mobility group box-1 (HMGB1), were observed compared to the control group. LPS induced distinct damage in the bovine endometrium, characterized by morphological changes and increases in HABP1 and HMGB1 expression. PTGS-2 inhibitors CAY10404 and NS398 effectively decreased the secretion of PGE₂ and the expression of prostaglandin synthetases, pro-inflammatory factors and DAMPs, and alleviated LPS-induced tissue damage. These results indicate that PGE₂ accumulates via PTGS-2 and mPGES-1 and induces tissue damage by upregulating pro-inflammatory factors and DAMPs in LPS-treated bovine endometrial explants. These findings provide a basis for the effect of PGE₂ on LPS-treated bovine endometrium, and suggest a potential target for curing endometritis.

Sulfasalazine treatment can cause a positive effect on LPS-induced endotoxic rats

The aim of this study, was to determine the effect of sulfasalazine for different periods of time reduces disseminated intravascular coagulation, inflammation and organ damages by inhibiting the nuclear factor kappa beta pathway. The study was performed with 30 Wistar albino rats and the groups were established as Control group, LPS group; endotoxemia was induced with LPS, SL5 group: sulfasalazine (300 mg/kg, single dose daily) was administered for 5 days before the LPS-induced endotoxemia, and LS group: sulfasalazine (300 mg/kg, single dose) was administered similtenously with LPS. Hemogram, biochemical, cytokine (IL-1β, IL-6, IL-10, TNF-α) and acute phase proteins (HPT, SAA, PGE2) analyzes and oxidative status values were measured from blood samples at 3 and 6 h after the last applications in the all groups. The rats were euthanized at 6 h and mRNA levels of BCL2 and BAX genes were examined from liver and brain tissues. Sulfasalazine reduced the increased IL-1β, IL-6, TNF-α and PGE₂ levels and significantly increased anti-inflammatory cytokine IL-10 levels. In addition, decreasing of ATIII level was prevented in the SL5 group, and decreasing of fibrinogen levels were prevented in the LS and SL5 groups within first 3 h. In LPS group, leukocyte and thrombocyte levels were decreased, however sulfasalazine application inhibited decreases of leukocyte levels in LS and SL5 groups. In addition, sulfasalazine inhibited the decrease of total antioxidant capacity and unchanged apoptosis in brain and liver. In conclusion, the use of sulfasalazine in different durations reduce the excessive inflammation of endotoxemia cases.