Uterine Cytokine Profile in a Rat Model of Endometritis

Endometrial responses to bacterial and viral infection: a scoping review

BACKGROUND

The endometrium is a highly dynamic tissue that undergoes dramatic proliferation and differentiation monthly in order to prepare the uterus for implantation and pregnancy. Intrauterine infection and inflammation are being increasingly recognized as potential causes of implantation failure and miscarriage, as well as obstetric complications later in gestation. However, the mechanisms by which the cells of the endometrium respond to infection remain understudied and recent progress is slowed in part owing to similar overlapping studies being performed in different species.

OBJECTIVE AND RATIONALE

The aim of this scoping review is to systematically summarize all published studies in humans and laboratory animals that have investigated the innate immune sensing and response of the endometrium to bacteria and viruses, and the signaling mechanisms involved. This will enable gaps in our knowledge to be identified to inform future studies.

SEARCH METHODS

The Cochrane Library, Ovid Embase/Medline, PubMed, Scopus, Google Scholar, and Web of Science databases were searched using a combination of controlled and free text terms for uterus/endometrium, infections, and fertility to March 2022. All primary research papers that have reported on endometrial responses to bacterial and viral infections in the context of reproduction were included. To focus the scope of the current review, studies in domesticated animals, included bovine, porcine, caprine, feline, and canine species were excluded.

OUTCOMES

This search identified 42 728 studies for screening and 766 full-text studies were assessed for eligibility. Data was extracted from 76 studies. The majority of studies focused on endometrial responses to Escherichia coli and Chlamydia trachomatis, with some studies of Neisseria gonorrhea, Staphylococcus aureus, and the Streptococcus family. Endometrial responses have only been studied in response to three groups of viruses thus far: HIV, Zika virus, and the herpesvirus family. For most infections, both cellular and animal models have been utilized in vitro and in vivo, focusing on endometrial production of cytokines, chemokines, and antiviral/antimicrobial factors, and the expression of innate immune signaling pathway mediators after infection. This review has identified gaps for future research in the field as well as highlighted some recent developments in organoid systems and immune cell co-cultures that offer new avenues for studying endometrial responses to infection in more physiologically relevant models that could accelerate future findings in this area.

WIDER IMPLICATIONS

This scoping review provides an overarching summary and benchmark of the current state of research on endometrial innate immune responses to bacterial and viral infection. This review also highlights some exciting recent developments that enable future studies to be designed to deepen our understanding of the mechanisms utilized by the endometrium to respond to infection and their downstream effects on uterine function.

The curative effect of ozonated bidistilled water on Escherichia coli-induced endometritis in rats

BACKGROUND

Endometritis is a prevalent and challenging condition that affects livestock, and its effective treatment is the use of intrauterine antibiotics. Antibiotic use may lead to negative consequences, including residue in tissues and the emergence of antibiotic resistance.

OBJECTIVES

The aim of this study was to assess the therapeutic potential of ozonated bidistilled water in the treatment of Escherichia coli-induced endometritis in rat models, comparing it to conventional antibiotic treatment.

METHODS

A total of 21 female Wistar Albino rats were used for this study. E. coli from the uterus of cows with endometritis at a concentration of 1.0 × 109 cfu/mL inoculated into rat uteruses. After inoculation, it was confirmed macroscopically that experimental endometritis was induced in all individuals. And, the rats with endometritis were randomly divided into three groups treated with intrauterine bidistilled water enriched with ozone, antibiotics and 0.9% NaCl. The uterine tissues were examined histopathologically.

RESULTS

In the semiquantitative analyses, significantly lower histopathological scores were observed for both the bidistilled water enriched with ozone and antibiotic-treated endometritis groups compared to the control group (p < 0.05).

CONCLUSIONS

Ozone-enriched bidistilled water can be used in the treatment of experimentally induced endometritis in rats, and can provide effective microbiological and histopathological improvement. Further studies involving larger populations of different species are needed to determine the medical suitability of this new treatment.

Selenomethionine protects against Escherichia coli-induced endometritis by inhibiting inflammation and necroptosis via regulating the PPAR-γ/NF-κB pathway

Endometritis, inflammation of the endometrium, is a major cause of subfertility in women. Selenomethionine (SeMet)is known to exert anti-inflammatory activity. We aimed to verify the protective roles of SeMet on Escherichia coli (E.coli)-induced endometritis. The extent of uterus damage was assessed by detecting histopathology and inflammatory mediators. The results revealed that SeMet significantly prevented E.coli-induced endometritis by attenuating uterine histopathology and inflammatory cytokine production. E.coli-induced MPO activity and MDA content were inhibited by SeMey. E.coli-induced ZO-1 and occludin were upregulated by SeMet. E.coli-induced necroptosis was also inhibited by SeMet. Additionally, E.coli-induced NF-κB activation was alleviated by SeMet. PPAR-γ expression was upregulated by SeMet. Notably, the protective effects of SeMet on endometritis were abolished by a PPAR-γ inhibitor. In conclusion, SeMet inhibits E.coli-induced endometritis by attenuating inflammation and necroptosis, which is mediated by the PPAR-γ/NF-κB signaling pathway.

Effects of Luteolin on Biofilm of Trueperella pyogenes and Its Therapeutic Effect on Rat Endometritis

Trueperella pyogenes is an opportunistic pathogen that causes suppurative infections in animals. The development of new anti-biofilm drugs will improve the current treatment status for controlling T. pyogenes infections in the animal husbandry industry. Luteolin is a naturally derived flavonoid compound with antibacterial properties. In this study, the effects and the mechanism of luteolin on T. pyogenes biofilm were analyzed and explored. The MBIC and MBEC of luteolin on T. pyogenes were 156 μg/mL and 312 μg/mL, respectively. The anti-biofilm effects of luteolin were also observed by a confocal laser microscope and scanning electron microscope. The results indicated that 312 μg/mL of luteolin could disperse large pieces of biofilm into small clusters after 8 h of treatment. According to the real-time quantitative PCR detection results, luteolin could significantly inhibit the relative expression of the biofilm-associated genes luxS, plo, rbsB and lsrB. In addition, the in vivo anti-biofilm activity of luteolin against T. pyogenes was studied using a rat endometritis model established by glacial acetic acid stimulation and T. pyogenes intrauterine infusion. Our study showed that luteolin could significantly reduce the symptoms of rat endometritis. These data may provide new opinions on the clinical treatment of luteolin and other flavonoid compounds on T. pyogenes biofilm-associated infections.

The NF-κB signaling pathway in mare's endometrium infiltrated with the inflammatory cells

Endometritis is an important issue decreasing mares' fertility. In the case of endometritis both, inflammatory cells infiltration and proinflammatory molecules production are regulated by various cellular and gene-regulatory mechanisms, including the nuclear factor-κB (NF-κB) dependent pathway. NF-κB signaling pathway has been recently studied in the equine endometrium in the context of endometrosis. Thus, this study aimed to determine gene transcription of NF-κB subunits (RelA; NF-κB1; NF-κB2), proinflammatory molecules (MCP-1; IL-6), and hyaluronan synthases (HAS 1; HAS 2; HAS 3) in endometritis and compare them with the intensity and type of inflammatory cell infiltration. Endometrial samples, collected post-mortem from cyclic mares in estrus or diestrus, were classified histologically and examined using quantitative PCR. Transcription NF-κB subunits genes did not differ with either inflammatory intensity or type of inflammatory cell infiltration. Transcription of MCP-1 and IL-6 genes increased with the severity of inflammation, with the involvement of HAS 3 and HAS 2 genes, as opposed to HAS 1 genes. These proinflammatory molecules and hyaluronan synthases in the equine inflamed endometrium do not seem to be regulated by the NF-κB pathway. Hence, separate signaling pathways for the development and progression of equine endometritis and endometrosis may be suggested.

The Effect of Ascorbic Acid on Interleukin-10 and Tumor Necrosis Factor-α Cytokines in Rattus norvegicus with Endometritis

BACKGROUND: Endometritis is a gynecological disease characterized by inflammation of the endometrial glands and stroma. Inflammatory stimuli or tissue injury induce inflammatory pain through the release of cytokines. Ascorbic acid (AA) is a water-soluble Vitamin that plays a role in inhibiting the production of proinflammatory cytokines and increases the expression of anti-inflammatory cytokines. AIM: The purpose of this study was to find out the association between administration of AA and inflammatory cytokines in experimental animals Rattus norvegicus with endometritis. METHODS: The research was conducted using virgin female R. norvegicus laboratory mice weighing 250–300 g and aged 11–12 weeks with an estrus cycle of 5–6 days. Mice with regular oestrous cycles were randomly divided into three groups: group 1 was given 200 L of water orally without Escherichia coli inoculation and represented a negative control. Groups 2 and 3 were inoculated (50 L/rat) E. coli intravaginally, 106 colony-forming unit/mL, Group 2 was not given AA and the other side Group 3 was assigned AA. The interleukin (IL)-10 and tumor necrosis factor (TNF)-α _cytokines examination was carried out by histopathological examination through a biopsy of the endometrial tissue. Hypothesis testing on the data was analyzed by the Kruskal Wallis test using Statistical Package for Social Sciences. RESULTS: Data from the current study revealed that the highest mean value of IL-10 was found in the negative control group (2.5) and the lowest value in the positive control group (1.3). Regarding TNF-α _the highest mean value (2.8) was found in the treatment group and the lowest mean value (2.1) was found in the treatment group. Using the Kruskal Wallis test, IL-10 and TNF-α _showed insignificant results (p = value 0.304 and 0.145 respectively). CONCLUSIONS: The administration of AA did not affect the decrease in TNF-α _or the upregulation of IL-10 as anti-inflammatory cytokines.

Revealing active ingredients, potential targets, and action mechanism of Ermiao fang for treating endometritis based on network pharmacology strategy

ETHNOPHARMACOLOGICAL RELEVANCE

Ermiao fang (EMF) is a traditional Chinese medicinal herbal formula from ancient times and recorded in the pharmacopeia of the People's Republic of China. It is composed of two typical Chinese herbal medicines, Cortex Phellodendri (Huangbai), the bark of Phellodendron chinensis Schneid. (Rutaceae), and Rhizoma Atractylodis (Cangzhu), the rhizome of Atractylodes lancea (Thunb.) DC. (Compositae). EMF has been clinically used for the treatment of endometritis for many years in China.

AIM OF THE STUDY

This study was aimed to identify the active ingredients, potential targets, and mechanism of action of EMF for the treatment of endometritis.

MATERIALS AND METHODS

In this research, the pharmacological effects of EMF on endometritis were first evaluated by establishing a rat model of endometritis. A network pharmacology-based analytical strategy was then used to predict its targets and signaling pathways. An endometritis-related protein target and compound database was built for EMF. The compounds in EMF and those absorbed into the blood were identified by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS). High-throughput virtual screening and molecule docking methods were used to predict the protein targets of EMF. The surface plasmon resonance analysis (SPR) method was used to validate the affinity between the compound and proteins. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was used to predict the related pathways. Western blotting analysis was used to evaluate the expression of key proteins in the related pathways.

RESULTS

The animal study showed that EMF could reduce uterine inflammation in rats with endometritis. Then, an ingredient database including 187 compounds and a protein target database including 836 proteins were constructed. Twenty-four compounds in EMF were identified by UHPLC-Q-TOF/MS, among which eight compounds were present in rat plasma after an oral administration of EMF. Afterward, 39 potential target proteins were predicted by the high-throughput screening method, and 20 of them were selected after further screening using molecular docking. Subsequently, an ingredient-target network was constructed, and the target proteins were classified into the NF-κB and MAPK signal pathways by KEGG pathway enrichment analysis. Finally, the affinity between the active ingredients and the target proteins was verified by SPR. The Western blotting analysis showed that EMF significantly inhibited the elevated NF-κB and MAPK pathway proteins in rats with endometritis.

CONCLUSIONS

EMF exhibited a significant pharmacological effect on rats with endometritis. Network pharmacology analysis revealed that eight compounds were absorbed into the blood after oral administration and interacted with 20 targets. Western blotting analysis indicated that EMF exerted anti-inflammatory effects by inhibiting the NF-κB and MAPK signaling pathway proteins in the treatment of endometritis.

Cortisol inhibits the Escherichia coli-induced endometrial inflammatory response through NF-κB and MAPK pathways in postpartum goats

Glucocorticoids have been widely used as anti-inflammatory therapies. The mechanisms of cortisol action in goat does with endometritis, however, have not been reported. The aim of this study was to investigate the mechanism of cortisol in modulation of effects of E. coli-induced endometritis in the does. Does (n = 24) were assigned to four groups (n = 6): control, E. coli, cortisol, and E. coli + cortisol groups. Does in the cortisol and E. coli + cortisol group were treated with cortisol from 3 days before E. coli inoculations occurred to 36 days post-partum. Does in the E. coli and inoculation groups were administered via intrauterine infusion E. coli O₅₅ (10⁹ CFU/mL) at 0 h. Physical indicators, macroscopic and microscopic changes in the endometrium, uterine secretion cytology and bacteriology were evaluated before (0 h) and at 6, 12, 24, 48, and 72 h after E. coli inoculation. The TLR4 and pro-inflammatory cytokine mRNA transcripts were detected using qPCR. The activations of NF-κB and MAPK signaling pathways were detected using Western blot procedures. As a result, cortisol inhibited the inflammatory response of does by reducing the clinical symptoms, morphological endometrial damage, % PMN in uterine secretions, relative abundance of inflammatory gene mRNA transcripts in the endometrium of does. Cortisol inhibited NF-κB activity by reducing MyD88 and IκB phosphorylation. Treatment with cortisol suppressed the phosphorylation of ERK1/2, p38MAPK, and JNK. These results indicate the anti-inflammatory effect of cortisol in the endometrium of does may be regulated by NF-κB and MAPK pathways.

Therapeutic effects of resveratrol in Escherichia coli-induced rat endometritis model

Endometritis is an inflammatory disorder of the endometrial lining of the uterine tissue in postpartum stage. Endometritis mostly progresses subclinically and causes infertility through the disruption of the hormonal balance. It has been shown in many studies that resveratrol has anti-inflammatory and antioxidant properties. However, the possible beneficial effects of resveratrol in endometritis have not been determined yet. The aim of the present study is to evaluate the treatment potential of resveratrol in an experimentally induced endometritis model in rats. Endometritis was induced in 12-week-old female, nonpregnant, Sprague Dawley rats. The animals were divided into six groups: control (NaCl 0.9%) and endometritis (NaCl 0.9%), marbofloxacin + PGF_2α, marbofloxacin, marbofloxacin + resveratrol, and resveratrol groups. To induce endometritis, 5 mg/kg/s.c. progesterone was given for 5 days, and then Escherichia coli (50 μl, 1 × 10⁵ cfu/rat) was injected in the right cornu uteri following laparotomy. Sixteen hours after bacterial inoculation, the treatment protocol was applied for 14 days. At the end of the experiment, the total oxidant status (TOS) and total antioxidant status (TAS) were examined spectrophotometrically in uterus tissues. The severity of inflammation in uterus samples and follicular activity in ovarian tissues were histopathologically evaluated. In addition, serum cytokine levels were determined. While TAS in uterine tissue significantly increased in the resveratrol group when compared to that of the other groups (p < 0.05), there was no difference between the groups in TOS (p > 0.05). The inflammation of the endometrium and the numbers of corpus luteum in the endometritis group were highly significant when compared to those of the other groups (p < 0.05). The recovery of inflammation and follicular activity were similar to those of the other groups in resveratrol group. However, it was realized that resveratrol administration reduced serum cytokine levels. According to the results of the current study, resveratrol was found to be effective in the treatment of endometritis with its antioxidant and anti-inflammatory functions.

Association between Mannheimia haemolytica infection with reproductive physiology and performance in small ruminants: A review

Mannheimiosis or pneumonic pasteurellosis commonly occurs in small ruminants. Mannheimiosis is caused by Mannheimia haemolytica (M. haemolytica) a Gram-negative coccobacillus producing acute febrile and infectious condition resulting in death of animal if not diagnosed and treated promptly. M. haemolytica serotype A2 is a commensal of the nasopharynx, gaining access to the lungs when host defenses are compromised by stress or infection in small ruminants. Till date, there is a vast literature and research that has been conducted on the pathogenesis of M. haemolytica invariably on respiratory system and its related immune system and mechanisms. From the clinical point of view, infection or diseases involving vital organs will systemically affect the production and performance of the infected animal. Therefore, there is a huge gap of knowledge and research to answer the question whether there is any association between M. haemolytica infection with reproductive physiology and performance in small ruminants and how it affects the productivity level. This review will explore the possibilities of involvement and new potential research to be carried out to determine the involvement of male and female reproductive system with M. haemolytica infection among small ruminants.

The Anti-Inflammatory Effect of Feiyangchangweiyan Capsule and Its Main Components on Pelvic Inflammatory Disease in Rats via the Regulation of the NF-κB and BAX/BCL-2 Pathway

Although gastroenteritis and pelvic inflammatory disease (PID) occur in the gastrointestinal tract and pelvis, respectively, they display similar pathogeneses. The incidence of inflammation in these conditions is usually associated with dysbacteriosis, and, at times, they are caused by the same pathogenic bacteria, Escherichia coli and Streptococcus aureus. Feiyangchangweiyan capsule (FYC) is a traditional Chinese patent medicine that is widely used to treat bacterial dysentery and acute and chronic gastroenteritis. However, whether it has an effect on PID is unclear. The aim of this study was to investigate the anti-inflammatory effect of FYC and its main components, gallic acid (GA), ellagic acid (EA), and syringin (SY), on a pathogen-induced PID model and illustrate their potential mechanism of action. Female specific pathogen-free SD rats (n = 1110) were randomly divided into control, PID, FYC, GA, EA, SY, GA + EA, GA + SY, EA + SY, GA + EA + SY, and Fuke Qianjin capsule (FKC) positive groups. Histological examination and enzyme-linked immunosorbent assay (ELISA) were carried out as well as western blot analysis to detect the expression of NF-κB, BAX, BCL-2, and JNK. In this study, FYC and its main components dramatically suppressed the infiltration of inflammatory cells, reduced the production of IL-1β, TNF-α, and MCP-1, and elevated the IL-10 level to varying degrees. We also found that FYC and its main components inhibited the expression of BAX induced by infection and increased the expression of Bcl-2. FYC, GA, EA, and SY could also block the activation of the NF-κB pathway. Finally, we found that the phosphorylation of JNK could be decreased by FYC, GA, and SY. FYC and its main components exhibit anti-inflammatory effect on a pathogen-induced PID model by regulating the NF-κB and apoptosis signaling pathways.