The histopathologic scoring criteria.

Objective
The aim of this study was to investigate the anti-inflammatory effect of Rosiglitazone (RGZ) on lipopolysaccharide (LPS) -induced Endometritis and explore its possible mechanism.
Methods
The preventive and therapeutic effects of RGZ on Endometritis were studied in vivo and in vitro. A total of 40 female C57BL/6 mice were randomly divided into the following 4 groups: RGZ+LPS, RGZ control, LPS and DMSO control. The mice uterine tissue sections were performed with HE and immunohistochemical staining. Human endometrial stromal cells (HESCs) were cultured, and different concentrations of LPS stimulation groups and RGZ and/or a TLR4 signaling inhibitor TAK-242 pretreatment +LPS groups were established to further elucidate the underlying mechanisms of this protective effect of RGZ.
Results
The HE results in mice showed that RGZ+LPS group had less tissue loss than LPS group. Immunohistochemical staining (IHC) results showed that the expression of TLR4 after RGZ treatment was significantly lower than that in LPS group. These findings suggested that RGZ effectively improves the pathological changes associated with LPS-induced endometritis by inhibiting TLR4. Reverse transcription-polymerase chain reaction and western blot analysis demonstrated that RGZ pretreatment suppresses the expression of Toll-like receptor 4 (TLR4) and its downstream activation of nuclear factor-κB (NF-κB). In vitro, RGZ inhibited LPS-stimulated expression of proinflammatory cytokines in a dose-dependent manner and also downregulated LPS induced toll-like receptor 4 (TLR4) expression and inhibited phosphorylation of LPS-induced nuclear transcription factor-kappa B (NF-κB) P65 protein.
Conclusions
These results suggest that RGZ may inhibit LPS-induced endometritis through the TLR4-mediated NF-κB pathway.