The effect and mechanism of selenium supplementation on the proliferation capacity of bovine endometrial epithelial cells exposed to lipopolysaccharide in vitro under high cortisol background.

Bovine endometritis severely inhibits uterine repair and causes considerable economic loss. Besides, parturition-induced high cortisol levels inhibit immune function, reduce cell proliferation, and further inhibit tissue repair. Selenium (Se) is an essential trace element for animals to maintain normal physiological function and has powerful antioxidant functions. This study investigated whether Se supplementation reduces endometrial damage and promotes tissue repair in cows with endometritis under stress and explored the underlying mechanism. Primary bovine endometrial epithelial cells were isolated and purified from healthy cows. The cells were treated with different combinations of lipopolysaccharide (LPS), cortisol, and various concentrations of Se. Data showed that LPS stimulation inhibited cell proliferation and increased cell apoptosis. High levels of cortisol further exacerbated these effects. Flow cytometry, scratch wound healing tests, and 5-ethynyl-2'-deoxyuridine (EdU) proliferation assays showed that Se supplementation promoted cell cycle progression, cell migration, and cell proliferation in the presence of LPS and cortisol. The quantitative PCR results showed that the expression of related growth factors was increased after Se supplementation. After administering various inhibitors, we further demonstrated that Se supplementation decreased the activity of glycogen synthetase kinase 3ß (GSK-3ß) through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway to reduce the degradation of ß-catenin except the Wnt signal to promote cell proliferation. In conclusion, Se supplementation attenuated the cell damage induced by LPS at high cortisol levels and increased cell proliferation to promote uterine repair by elevating the mRNA expression of TGFB3 and VEGFA and activating the PI3K/AKT/GSK-3ß/ß-catenin signaling pathway.

After parturition, endometritis is a common bovine disease, which hinders endometrial repair and reduces bovine economic value. Besides, parturition-induced high cortisol levels cause immunosuppression, aggravate infection, and further inhibit cell proliferation and tissue repair. As an essential trace element, adding selenium to feed helps to maintain the normal physiological function of animals. This study developed a cellular model using lipopolysaccharide (LPS) and cortisol to simulate cows with endometritis in stress conditions. The results showed that Se supplementation attenuated bovine endometrial epithelial cell damage and promoted their proliferation in the presence of LPS and high cortisol levels, which are positively correlated with the concentration of Se. Besides, this study proved another molecular mechanism for Se to regulate ß-catenin except for the Wnt signal by affecting the ß-catenin degradation pathway.

Protective effect of the total flavonoids from Clinopodium chinense against LPS-induced mice endometritis by inhibiting NLRP3 inflammasome-mediated pyroptosis.

ETHNOPHARMACOLOGICAL RELEVANCE: Clinopodium chinense (Benth.) O. Kuntze (C. chinense) is a Chinese herbal medicine used in treating gynecological hemorrhagic diseases for hundreds of years. Flavonoids are one kind of the major components in C. chinense. The flavonoids of C. chinense (TFC) have a vital role in treating endometritis but the underlying therapeutic mechanisms of TFC against endometritis have been rarely reported. AIM OF THE STUDY: To elucidate the therapeutic effect and possible mechanisms of TFC against lipopolysaccharide (LPS)-induced endometritis in vivo and LPS-induced primary mouse endometrial epithelial cells (MEECs) injury in vitro. MATERIALS AND METHODS: The holistic phytochemicals of the TFC and TFC-contained serum were screened and identified using UPLC-Q-TOF-MS. The model of endometritis was established by intrauterine injection of LPS (5 mg/mL) into female BALB/c mice, and the model mice were treated with TFC for 7 days. The value of MPO was measured by Myeloperoxidase assay kit, the pathological changes in the endometrium were evaluated using H&E staining and transmission electron microscope (TEM), the secretions of IL-18, IL-1ß and TNF-α were determined by ELISA kits, the mRNA expressions of IL-18, IL-1ß and TNF-α were determined by RT-PCR assay, and the protein levels of TLR4, IKBα, p-IKBα, p65, p-p65, caspase-1, ASC, NLRP3 and GSDMD were measured by Western blot. Subsequently, MEECs were isolated from the uterus of pregnant female mice, injured by LPS for 24 h and incubated with the TFC-contained serum. Finally, cell viability, LDH release, hoechst 33342/PI staining, immunofluorescence staining, scanning electron microscope observation, ELISA assay, RT-PCR detection and Western blot analysis were carried out to further validate the therapeutic effect and the underlying mechanisms of TFC. RESULTS: A total of 6 compounds in the plasma of mice after being intragastric administrated of TFC were identified. The results in vivo showed that TFC significantly reduced MPO value and alleviated pathological injury of the endometrium. Furthermore, TFC significantly decreased the serum IL-18, IL-1ß and TNF-α levels, and the mRNA levels of IL-18, IL-1ß and TNF-α. TFC also inhibited the expressions of TLR4, p-IKBα, p-p65, caspase-1, ASC, NLRP3 and GSDMD. Besides, compared with the model group in MEECs cells, TFC-contained serum prevented pyroptosis, decreased the levels of IL-18 and IL-1ß, and inhibited the mRNA expressions of IL-18, IL-1ß and GSDMD. TFC-contained serum also reversed the activation of NLRP3 inflammasome caused by nigericin, and restrainted the translocation of NF-κB into nuclear. CONCLUSIONS: TFC protects mice endometritis from the injury of LPS via suppressing the activation of NLRP3 inflammasome and pyroptosis, the underlying mechanisms of which were related to restraining the TLR4/NF-κB/NLRP3 pathway activation.

Ginsenoside Rb1 Mitigates Escherichia coli Lipopolysaccharide-Induced Endometritis through TLR4-Mediated NF-κB Pathway.

Endometritis is the inflammatory response of the endometrial lining of the uterus and is associated with low conception rates, early embryonic mortality, and prolonged inter-calving intervals, and thus poses huge economic losses to the dairy industry worldwide. Ginsenoside Rb1 (GnRb1) is a natural compound obtained from the roots of Panax ginseng, having several pharmacological and biological properties. However, the anti-inflammatory properties of GnRb1 in lipopolysaccharide (LPS)-challenged endometritis through the TLR4-mediated NF-κB signaling pathway has not yet been researched. This study was planned to evaluate the mechanisms of how GnRb1 rescues LPS-induced endometritis. In the present research, histopathological findings revealed that GnRb1 ameliorated LPS-triggered uterine injury. The ELISA and RT-qPCR assay findings indicated that GnRb1 suppressed the expression level of pro-inflammatory molecules (TNF-α, IL-1ß and IL-6) and boosted the level of anti-inflammatory (IL-10) cytokine. Furthermore, the molecular study suggested that GnRb1 attenuated TLR4-mediated NF-κB signaling. The results demonstrated the therapeutic efficacy of GnRb1 in the mouse model of LPS-triggered endometritis via the inhibition of the TLR4-associated NF-κB pathway. Taken together, this study provides a baseline for the protective effect of GnRb1 to treat endometritis in both humans and animals.

Acute endometritis induced by Escherichia coli in mares evaluated through color doppler ultrasonography / [Endometrite aguda induzida por Escherichia coli em éguas avaliadas por ultrassonografia com Doppler colorido]

The objectives of this study were to characterize the endometritis induced in mares using color Doppler ultrasonography and traditional exams. Experiment 1. Mares (n=20) were submitted to intrauterine inoculation with Escherichia coli. Uterine evaluation was performed at M0 and M1. Experiment 2. Animals were divided into two groups: control group (n=10), and treated group (n=10) using phytotherapeutic solution. In both groups, the uterine evaluation was performed at time T1, T2, and T3. Experiment 3: Uterine evaluation was compared after antibiotic therapy, phytotherapy, and M0. For statistical analysis, the Tukey test, t Student, and Anova test were applied. Experiment 1. The mean values of vascularization at M1 were significantly higher than those obtained at M0 (P<0.05). Bacterial growth was observed in all samples collected. Experiment 2. The mean value of vascularization at time T1 in both groups was significantly higher (P<0.05) compared to M2 and M3. Experiment 3. After antibiotic therapy, the vascularization of the body and uterine horns was not equivalent to the vascularization presented at M0. We can conclude that it was not possible to correlate results obtained by color Doppler ultrasonography with the traditional findings for the diagnosis of endometritis.(AU)

Os objetivos deste estudo foram caracterizar a endometrite induzida em éguas utilizando-se a ultrassonografia com Doppler colorido e exames tradicionais. Experimento 1: as éguas (n=20) foram submetidas à inoculação intrauterina com Escherichia coli. A avaliação uterina foi realizada em M0 e M1. Experimento 2: os animais foram divididos em dois grupos: grupo controle (n=10) e grupo tratado (n=10), sendo usada solução fitoterápica. Nos dois grupos, a avaliação uterina ocorreu nos momentos T1, T2 e T3. Experimento 3: a avaliação uterina foi comparada após antibioticoterapia, fitoterapia e M0. Para análise estatística, foram aplicados os testes de Tukey, t de Student e ANOVA. Experimento 1: os valores médios de vascularização em M1 foram significativamente maiores que os obtidos no M0 (P<0,05). Houve crescimento bacteriano em todas as amostras coletadas. Experimento 2: o valor médio da vascularização no tempo T1 nos dois grupos foi significativamente maior (P<0,05) do que o obtido em M2 e M3. Experimento 3: após antibioticoterapia, a vascularização do corpo e dos cornos uterinos não era equivalente à vascularização apresentada em M0. Pode-se concluir que não foi possível correlacionar os resultados obtidos pela ultrassonografia com Doppler colorido com os achados tradicionais para o diagnóstico de endometrite.(AU)

Selenium alleviates lipopolysaccharide-induced endometritis via regulating the recruitment of TLR4 into lipid rafts in mice.

Selenium (Se) is an essential trace element for living organisms and plays diverse biological roles. Endometritis is a common reproductive disorder in dairy cows, causing huge economic losses. In this study, we explored the effects of Se on lipopolysaccharide (LPS)-induced endometritis in mice and expounded its underlying mechanism of action. We validated the anti-inflammatory effects of Se in vivo by establishing a mouse model of endometriosis induced by LPS. Se significantly reversed the LPS-induced uterine histopathological changes, MPO activity and inflammatory cytokine levels in vivo. Simultaneously, TLR4 and its downstream signaling pathways, lipid rafts and cholesterol levels in the tissues were also attenuated by Se under LPS stimulation. In addition, the molecular mechanism of the Se anti-inflammatory effect was clarified in mouse endometrial epithelial cells. Se inhibited TLR4-mediated NF-κB and IRF3 signal transduction pathways to reduce the production of inflammatory factors. We found that Se promoted the consumption of cholesterol to suppress the lipid rafts coming into being and inhibited the TLR4 positioning to the lipid raft to prevent the inflammatory response caused by LPS. Meanwhile, Se activated the LxRα-ABCA1 pathway to cause the outflow of cholesterol in cells. The anti-inflammatory effect of Se was disrupted by silencing LxRα. In conclusion, Se exerted anti-inflammatory effects most likely by the LxRα-ABCA1 pathway activation, which inhibited lipid rafts by depleting cholesterol and ultimately impeded the migration of TLR4 to lipid rafts.

Matrine alleviates Staphylococcus aureus lipoteichoic acid-induced endometritis via suppression of TLR2-mediated NF-κB activation.

Endometritis is one of the main diseases that causes great economic losses in the dairy industry. Recent studies have shown that matrine extracted from the traditional Chinese herb Sophora flavescens is an alkaloid with a broad range of bioactivities. Here, we aimed to investigate the protective effects of matrine on Staphylococcus aureus lipoteichoic acid (LTA)-induced endometritis in mice and elucidate the possible molecular mechanisms in vitro. Histopathological changes showed that matrine remarkably attenuated the uterus injury in a mouse model of LTA-induced endometritis. qPCR and ELISA results showed that matrine dose-dependently reduced the expression of pro-inflammatory cytokines (TNF-α and IL-1ß). To further elucidate the underlying mechanisms of this protective effect of matrine, LTA-stimulated bovine endometrial epithelial cells (bEECs) were employed in this study. The results demonstrated that TLR2 expression and its downstream nuclear factor (NF)-κB activation were both suppressed by matrine treatment. Furthermore, a small interference RNA targeting TLR2 gene mimicked matrine in its inhibition on LTA-induced activation of TLR2 and NF-κB. In conclusion, these findings suggest the protective effect of matrine against LTA-induced endometritis through negative regulation of TLR2-mediated NF-κB pathway.

Melatonin inhibits endoplasmic reticulum stress-associated TXNIP/NLRP3 inflammasome activation in lipopolysaccharide-induced endometritis in mice.

Endometritis, an inflammatory response of the uterus tissue, is characterized by the production of inflammatory cytokines and migration of neutrophil (PMN) into the uterus tissue. Melatonin has been demonstrated to have anti-inflammatory and antioxidant effects. The purpose of this study was to investigate the protective effects of melatonin on lipopolysaccharide (LPS)-induced endometritis in mice. An endometritis model was induced by LPS and melatonin was given 1 h before LPS treatment. The results showed that melatonin inhibited LPS-induced pathologic changes, Myeloperoxidase (MPO) activity, and levels of interleukin-1 beta (IL-1ß). Melatonin also inhibited LPS-induced thioredoxin-interacting protein (TXNIP)/NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome and nuclear factor kappa B (NF-κB) activation, reactive oxygen species (ROS) production, and endoplasmic reticulum (ER) stress. Furthermore, melatonin was found to increase AMPK activity. In conclusion, our results demonstrated that melatonin inhibited ER stress-associated TXNIP/NLRP3 inflammasome activation with a regulation of adenosine monophosphate activated protein kinase (AMPK) in LPS-induced endometritis. Melatonin may serve as a promising nutritional supplement for the treatment of endometritis.

Selenium Deficiency Facilitates Inflammation Through the Regulation of TLR4 and TLR4-Related Signaling Pathways in the Mice Uterus.

Selenium (Se) is an essential nutritional trace element that affects the development and function of the reproductive system. Endometritis is a reproductive obstacle disease that can seriously reduce the reproductive capacity of animal. To study the effects of dietary Se deficiency on lipopolysaccharide (LPS)-induced mice endometritis, we generated a model of LPS-induced mice endometritis. The Se content in uterine tissues was detected by fluorescence spectrophotometry. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR). The extent of phosphorylation of IκBα, NF-κB p65, ERK, JNK, and p38 and the expression of Toll-like receptor 4 (TLR4) were detected with Western blots. The TLR4 messenger RNA (mRNA) was analyzed with qRT-PCR. The results indicated that dietary Se intake significantly influenced Se levels in uterine tissues. The Se-deficient mice model was successfully replicated, and Se deficiency exacerbated uterine tissue histopathology; increased the expression of TNF-α, IL-1ß, and IL-6; facilitated the activation of TLR4; and enhanced the phosphorylation of IκBα, p65, ERK, JNK, and p38 in LPS-induced mice endometritis. Also, the effects were inhibited by a supplement of Se. In conclusion, our studies demonstrated that Se deficiency makes mice uterus more prone to inflammation. An appropriate Se supplement could enhance the immune condition of the uterus.