Effect of corticotherapy on proteomics of endometrial fluid from mares susceptible to persistent postbreeding endometritis

The objective was to determine the effects of corticotherapy, in the presence and absence of uterine inflammation, on proteomics of endometrial fluid from mares susceptible to endometritis. In 11 mares, estrus was induced seven times with 5 mg PGF_2α given at 14-day intervals. The first estrus was a control (no treatment). During the third estrus, mares received glucocorticoid (GC) treatment (20 mg isoflupredone acetate) every 12 h, for three consecutive days. The fifth estrus was the Infected treatment (intrauterine infusion of 1 × 10⁹ colony-forming unit/mL Streptococcus equi subspecies zooepidemicus). Finally, the seventh was a combination of GC + Infected treatment (infusion of bacteria 24 h after the first GC treatment). At 12 h after the end of each treatment, uterine samples were collected and submitted to two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) for protein separation and mass spectrometry. Both GC treatment and uterine lumen infection induced proteomic alterations in the endometrial fluid of susceptible mares, characterized by an increase, decrease, or both in the relative optic density and/or frequency of inflammatory acute phase proteins (APP), with major alterations occurring when corticotherapy was applied in the presence of an infectious process. Corticotherapy in the presence of infection increased α₁-antitrypsin (AAT), transthyretin (TT), and actin, but reduced immunoglobulin G, whereas intrauterine infection increased haptoglobin (Hp) and apolipoprotein A-1 (ApoA-1) and decreased transferrin (TF). Infection reduced levels of α₁-antitrypsin and transthyretin, whereas corticotherapy in the presence of infection increased their frequency. We concluded that GC influenced the immune response, not only as suppressors, but also as enhancers of local defense mechanisms, through an immunomodulatory action. Short-term corticotherapy could be beneficial for treatment of uterine infectious processes in the mare.     

Comparison of three diagnostic methods to identify subclinical endometritis in mares

The objective of this study was to compare the accuracy of a uterine swab (US), a cytological brush (CB) and an endometrial biopsy (EB) to detect subclinical endometritis in mares. Cytological and bacteriological results of all three techniques were related to histological occurrence of polymorphonuclear neutrophils (PMNs) in the stratum compactum, commonly known as ‘best standard'; to diagnose endometritis.Samples were taken from 55 mares of different breeds without clinical signs of endometritis. Samples for US, CB and EB were collected, smeared on a microscopic slide and cultured for bacterial growth. Endometrial biopsy samples were additionally stored in 4% formaldehyde for histological analysis. Bacteriological cultures and cytological samples of all techniques were classified as negative (no uterine pathogens in monoculture; < 2% PMNs) or positive (uterine pathogens in > 90% of the grown colonies; > 2% PMNs) for endometritis. Uterine pathogens were diagnosed in 20.0% of the mares. Isolation of pathogens was not associated with positive cytological findings (r = −0.23; P = 0.87). None of the six mares with an Escherichia coli infection (10.9%) showed a positive cytological result. In contrast, two of five mares infected with Streptococcus zooepidemicus had a positive cytological result.Histologically, the presence of PMNs in the stratum compactum was regarded as positive for endometritis when the mare was in diestrus at time of sampling. Compared to the ‘best standard', sensitivity for cytology of CB, US and EB was 0.17, 0.00 and 0.25, respectively. Specificity for cytology of CB, US and EB was 0.83, 0.93 and 0.85, respectively. Sensitivity of uterine culture was 0.25, 0.33 and 0.25 for CB, US and EB, respectively. Specificity for culture of CB, US and EB was 0.80, 0.83 and 0.95, respectively. In conclusion, cytological or bacteriological examinations alone provide a high incidence of false negative results. Sensitivity of cytology combined with bacteriology of CB was 0.42. A combination of a bacteriological and a cytological examination of a CB sample improved the diagnostic performance in subfertile mares. Based on these results, we can recommend the CB to improve the diagnosis of subclinical endometritis in the mare compared to the US alone as currently used routine method.     

Effect of susceptibility to endometritis on specific antibody in the endometria of mares

Endometrial biopsies were collected on two occasions from mares resistant to (n = 3) and once from mares susceptible to persistent endometritis (n = 6). The endometrial tissue was minced and cultured in vitro for 24 h. No hemolytic complement activity was detected in the endometrial culture supernatant. Endometrial culture supernatant from mares with persistent endometritis contained titers of antibodies to Streptococcus zooepidemicus similar to those from resistant mares. However, the culture supernatant of biopsies from mares with endometritis was less effective (P < 0.05) at opsonizing S. zooepidemicus in vitro.     

Endometritis in the mare: A comparison between reproductive history and uterine biopsy as techniques for predicting susceptibility of mares to uterine infection

Thirty mares with no clinical signs of endometritis were categorized as being susceptible or resistant to uterine infection depending on whether or not they had a history of recurrent endometritis. The same mares were then independently classified as susceptible or resistant on the basis of their uterine biopsies; those with significant endometrial degeneration were considered to be susceptible to endometritis. The mares then received an intrauterine inoculation of pathogenic Streptococcus zooepidemicus . Those mares which eliminated bacteria by 10 d after inoculation were considered truly resistant to endometritis, whereas those still infected at 10 d were considered susceptible. The original classifications based on history or biopsy were compared to the inoculation results. A history of recurrent endometritis provided a more sensitive (0.90) and specific (0.95) indication of susceptibility to uterine infection than a uterine biopsy with significant endometrial degeneration (sensitivity 0.5, specificity 0.75).     

Evaluation of cytokine expression by blood monocytes of lactating Holstein cows with or without postpartum uterine disease

Whereas neutrophils are the main phagocytic leukocytes, monocytes and macrophages are actively involved in immunomodulation after infection. Recent studies have demonstrated that neutrophil function is impaired by the state of negative energy balance around parturition, and that cows that develop uterine disease have a greater degree of negative energy balance than healthy cows. The objectives of this study were to compare monocyte gene expression and protein secretion of selected cytokines from calving to 42 d after calving in Holstein cows that did or did not develop uterine disease. Real time quantitative RT-PCR (Tumor necrosis factor-α (TNFα), Interleukin (IL)-1β, IL-6, IL-8 and IL-10) and ELISA (TNFα, IL-1β and IL-8) were used to evaluate cytokine response following in vitro stimulation of blood-derived monocytes with irradiated E. coli. Relative to unstimulated cells, E. coli-stimulated monocytes from cows with metritis had lower gene expression of key pro-inflammatory cytokines than healthy cows from calving to 14 d after calving (TNFα at 0, 7, and 14 d after calving, IL-1β and IL-6 at 7 and 14 d after calving; P < 0.05). There were no significant differences between groups for expression of IL-8 or the anti-inflammatory cytokine IL-10. This was due, in part, to higher gene expression in unstimulated monocytes (TNFα, IL-1β, IL-6 and IL-10) in early lactation from cows with metritis. Expression of mRNA in stimulated cells (relative to housekeeping genes) was lower for TNFα (7 and 14 d postpartum) and for IL-10 (7 and 14 d postpartum) in cows with metritis. Concentration of TNFα was lower in the culture medium of E. coli-stimulated monocytes from cows with metritis than healthy cows at calving and 7 and 21 d after calving (P < 0.05). Circulating cytokine concentrations were not different between groups for IL-8 and were below the limits of detection for TNFα and IL-1β. Cytokine gene expression and production were similar between healthy cows and cows that developed endometritis, diagnosed cytologically at 42 d after calving. We concluded that altered levels of expression and production of pro-inflammatory cytokines postpartum could contribute to impaired inflammatory response and predispose cows to development of metritis.     

Characterization of the innate immune response in goats after intrauterine infusion of E. coli using histopathological, cytologic and molecular analyses

The objective was to characterize the innate immune response in dairy goats after intrauterine infusion of E. coli. A suspension of Escherichia coli (E. coli; 4 × 10⁹ cfu (cfu)/mL; experimental group, n = 6) or 5 mL PBS (control group, n = 6) were infused once into each uterine horn in goats at 25 days postpartum. Blood and endometrial biopsy samples were collected preinoculation (0 h) and at 3, 6, 12, 24, 72, 120, and 168 h post inoculation (pi). Relative gene expression analyses of Toll-like receptor4 (TLR4), tumor necrosis factorα (TNF-α), β-defensin2, and interleukins (IL-1β, IL-6, IL-8) were performed on RNA extracted from endometrial tissue and peripheral white blood cells (WBCs) using quantitative real-time PCR. Endometrial tissue was also used for histopathology and cytology. In experimental goats, the mRNA expression of TLR4 and proinflammatory cytokines were increased within 24 h pi (P < 0.01) in endometrium and WBCs. Similarly, expression of β-defensin2 was higher at 72 h pi in endometrium (P < 0.001), and at 120 h pi in WBCs (P < 0.05). The %PMNs in the experimental group increased up to 92.16 ± 3.95% at 3 h pi (P < 0.001). Endometrial histopathology revealed a severe inflammatory response at 3 to 12 h pi, whereas no changes were detected in the control group. In conclusion, intrauterine infusion of E. coli in goats resulted in a rapid activation of the local innate immune response, characterized by infiltration of PMNs into the endometrium and up-regulation of gene expression for TLR4, cytokines and β-defensin2.     

The effects of EDTA-Tris infusion on the equine endometrium

Four groups of five pony mares each were used to determine if the intrauterine infusion of EDTA-Tris solution caused adverse effects on the endometrium. The uteri of mares were infused with either saline or EDTA-Tris solution or biopsied or sham-biopsied without infusion. Acute endometritis developed in one (20%) to three (60%) mares in each group during the seven days following treatment, but there were no differences (P > 0.05) in the incidence of endometritis among the groups. Endometrial fibrosis was not evident in biopsies taken on days 14, 30 and 60 following infusion of saline or EDTA-Tris. It was concluded that the endometrial response to saline and EDTA-Tris was not different and that EDTA-Tris may be a useful adjunct to treatment of uterine infections in the mare.     

Endometrial expression of selected transcripts involved in prostaglandin synthesis in cows with endometritis

Several cytokines and prostaglandins play an important role in preparing the endometrium for implantation and mediating pro-inflammatory events. The aim of the present study was to examine mRNA expression of interleukin 1α (IL-1α), interleukin receptor antagonist (IL-1-RN), cytosolic prostaglandin E synthase (cPGES), microsomal PGES (mPGES-1 and mPGES-2) and lipocalin-type PGDS (L-PGDS) in the bovine endometrium. Endometrial epithelium samples were collected ex vivo from cows with different status of health at day 21-27 postpartum on a dairy farm. Three groups (n = 9 animals each) were defined: (1) healthy cows with no signs of endometritis (control group), (2) cows with subclinical endometritis, and (3) cows with signs of clinical endometritis. Oestrous cycle-dependent mRNA expression pattern was investigated using bovine endometrial epithelial cells from healthy uteri collected at the abattoir. These uteri were classified into post-ovulatory, early-to-mid luteal, late luteal or pre-ovulatory phase (n = 8 animals for each cycle phase). After collecting endometrial epithelium using the cytobrush-method, mRNA analysis was performed by real-time RT-PCR. L-PGDS, IL-1α and IL-1-RN mRNA were expressed significantly higher (P < 0.05) in the endometrium of cows with subclinical or clinical endometritis compared with healthy cows. A twofold lower cPGES mRNA expression (P < 0.05) was detected in cows with subclinical endometritis compared to healthy cows. L-PGDS and IL-1-RN mRNA expression was increased (P < 0.05) after ovulation compared with the pre-ovulatory or luteal phase, respectively. These results support the hypothesis that a dys-regulated cytokine and/or prostaglandin profile in the uterus could be induced by subclinical endometritis or clinical endometritis.     

Ceftiofur derivates in serum and endometrial tissue after intramuscular administration in healthy mares

Endometritis is one of the major problems in the horse breeding industry. The use of antibiotics for treatment of endometritis in the mare is recommended as best practice. The intrauterine application of antibiotics, however, has been under discussion over the last years because of concerns about its efficacy. The systemic use of antibiotics has been considered more effective because of its better distribution within the uterus. The objective of the present study was to determine the concentration of ceftiofur derivates in serum and endometrial tissue after intramuscular administration. Specifically, the authors tested the hypothesis that ceftiofur concentrations in serum and endometrial tissue remain above the minimum inhibitory concentration (MIC) for common uterine pathogens for 24 h. Nine mares in estrus received a single dose of 2.2 mg/kg ceftiofur hydrochloride intramuscular per kg of body weight. Blood samples and endometrial tissue were obtained immediately before treatment (−1 h) and 2 h and 24 h after treatment. Endometrial tissue was collected with a Kevorkian biopsy punch. Additional blood samples were collected 4 h and 10 h after treatment from the jugular veins. For determination of ceftiofur derivates in serum and endometrial tissue a high performance liquid chromatography (HPLC) assay was used. Results in serum and uterine tissue revealed greatest concentration of ceftiofur at 2 h and lowest concentrations at 24 h after treatment. Concentrations of ceftiofur at 2 and 24 h after treatment were significantly greater in serum than in endometrial tissue, but remained above the reported MIC for Streptococcus equi zooepidemicus and Escherichia coli in both serum and endometrial tissue until 24 h after treatment.     

Susceptibility to persistent breeding-induced endometritis in the mare: relationship to endometrial biopsy score and age, and variations between seasons

The objectives were to: (1) investigate the associations of age and endometrial biopsy score with uterine fluid retention after insemination; and (2) determine if a strict classification of susceptibility to persistent breeding-induced endometritis (PBIE) based on biopsy score, endometrial cytology, and fluid retention after inseminations, is consistent over subsequent breeding seasons. In Experiment 1, 57 mares were inseminated with 10⁹ freeze-killed sperm during estrus and evaluated for uterine fluid retention 48 h and 96 h after insemination. Comparisons were made between fluid retention and biopsy score or age. In Experiment 2, a subset of 14 mares was classified for susceptibility to persistent breeding-induced endometritis in two subsequent breeding seasons. Biopsy score and age were associated with fluid retention (P < 0.001). In addition, age was related to biopsy score (P < 0.001). Of the mares examined for susceptibility, 36% (5 of 14) changed status during subsequent seasons. Three mares changed to a more severe classification (intermediate to susceptible, or resistant to intermediate), whereas two mares changed to a less severe classification (susceptible to intermediate).     

Use of mesenchymal stem cells or autologous conditioned serum to modulate the inflammatory response to spermatozoa in mares

Current treatments for Persistent mating-induced endometritis such as uterine lavage and oxytocin therapy focus on aiding the uterus in removal of inflammatory products, but these treatments do not modulate the inciting inflammatory response. Biological treatments, such as autologous conditioned serum (ACS) and mesenchymal stem cells (MSCs), have been used in human and veterinary medicine for immunomodulation for over 10 years. The objectives of this project were to evaluate the ability of ACS or MSCs to modulate the inflammatory response to spermatozoa after breeding. Two experiments were performed with six normal mares in each study to evaluate the effects of intrauterine administration of ACS, dexamethasone, or a placebo (experiment 1), or allogeneic MSCs or a placebo (experiment 2) on the inflammatory response to spermatozoa using clinical and biochemical endpoints. Treatment with ACS and MSCs significantly (P < 0.05) reduced the number of neutrophils in the uterine lumen 6 hours after the sperm challenge. An increase (P < 0.05) in the anti-inflammatory cytokine IL-1Ra was observed after treatment with MSCs before exposure to spermatozoa. There was no difference in IL-1Ra concentration in mares treated with ACS, dexamethasone, or a placebo. Mesenchymal stem cells and ACS were able to modulate the immune response to spermatozoa in normal mares. The effect may be due to an increase in IL-1Ra in MSCs-treated mares, but other bioactive molecules may be responsible for the decrease in neutrophils in ACS-treated mares. Autologous conditioned serum and bone-derived culture expanded MSCs were able to modulate the uterine inflammatory response to spermatozoa in normal mares. Treatment with allogeneic stem cells may be beneficial if a similar modulation in inflammatory cytokines occurs in mares affected by persistent mating–induced endometritis.     

The use of dexamethasone administered to mares at breeding time in the modulation of persistent mating induced endometritis

The present study describes the effect of a single dose of dexamethasone administered to mares at time of breeding. In an initial experiment, the authors investigated safety of treatment. In a second experiment the effect of treatment on the uterine environment, fetal development and pregnancy outcome was examined. In the final part of the study, mares susceptible to persistent mating induced endometritis were identified, by means of a risk factor score system and the effect of treatment evaluated. Results indicated that dexamethasone administered at breeding time did not negatively impact on mares medical and reproductive traits. A reduced inflammatory response was observed post-mating in treated versus control mares and mares with multiple risk factors for susceptibility to persistent mating induced endometritis showed improved pregnancy rates following treatment. The authors concluded that a single dose of dexamethasone administered at the time of breeding is safe and can be used to modulate the uterine inflammatory response to breeding in susceptible mares.     

The functional competence of uterine-derived polymorphonuclear neutrophils (PMN) from mares resistant and susceptible to chronic uterine infection: a sequential migration analysis

The functional competence of uterine-derived polymorphonuclear neutrophils (PMNs) from 28 mares was measured for migration responsiveness by use of a chamber (filter) assay. Uterine infection was induced with Streptococcus zooepidemicus in mares considered resistant to chronic uterine infection (Grade I). In sequential analysis of uterine flushings obtained from these mares 5, 12, 15, 20, and 25 h after infection was induced, PMNs showed an initial rise at 12 h (from 5), then a general decline in migration response and in concentration of cells per ml from 12 through 25 h post-inoculation. In contrast, PMNs obtained from the uterine flushings from mares considered susceptible to chronic uterine infection (Grade III) demonstrated premature migration dysfunction 12 h after infection. Subsequent increases in functional competence of the PMNs were demonstrated at 15 and again at 25 h after induced infection. The concentration of uterine PMNs per ml from mares considered susceptible to chronic endometritis remained elevated from 12 through 25 h after inoculation, which suggests a possible continued recruitment of new PMNs from the peripheral circulation. The results of this study suggest that uterine-derived PMNs obtained from mares susceptible to chronic uterine infection have a compromised ability to migrate. This dysfunction may play an important role in rendering the endometrium (uterus) susceptible to chronic endometritis.     

Uterine Microbiology and Antimicrobial Susceptibility in Isolated Bacteria from Mares with Fertility Problems

Uterine microbiology and antimicrobial susceptibility was investigated in 239 mares with fertility problems in a prospective study in Sweden. Uterine swab samples were collected with double guarded swabs and transported overnight before being cultured. The Minimum Inhibitory Concentrations (MIC) was determined for a panel of antimicrobials. From 152 of the 239 mares at least one bacterial species was isolated, most frequently E. coli (104 isolates), β -haemolytic streptococci (31) and fungi (16). β -haemolytic streptococci were more frequently (p < 0.01) associated with clinical endometritis than with repeat breeding. The opposite was true for E. coli (p < 0.01). Among β -haemolytic streptococcal isolates some resistance was noted for 4 of 11 tested antibiotics, however, all isolates were susceptible to the widely used penicillin G. Among E. coli isolates enrofloxacin was the only of the 10 tested antibiotics for which no resistance was noted. Resistance was most commonly noted to cephalothin (39% of the isolates), streptomycin (22%), trimethoprim/sulphamethoxazole (15%) and ampicillin (11%). In conclusion, we show that both E. coli and β -haemolytic streptococci are frequently associated with fertility problems in mares and that antimicrobial resistance is a common feature of E. coli but also recognised for β -haemolytic streptococcal uterine isolates.     

Reproductive tract defense and disease in postpartum dairy cows

This paper briefly reviews recent data and concepts on the development and mitigation of infection and inflammation in the reproductive tract of dairy cows during the first 2 mo after calving. The incidence of metritis is typically between 10 and 20%, of clinical endometritis or purulent vaginal discharge (PVD) approximately 15%, and of subclinical or cytological endometritis a further 15%. Worse postpartum negative energy balance is associated with more severe or prolonged uterine inflammation. Changes in feed intake, expression of genes for pro-inflammatory cytokines, notably interleukin (IL) 1, IL6 and IL8, circulating concentrations of beta-hydroxybutyrate (BHBA) or nonesterified fatty acids (NEFA), and innate immune function precede both metritis and endometritis by several weeks. Infections with Escherichia coli and Arcanobacterium pyogenes are associated with both metritis and PVD. There are new data to suggest that specific virulence factors in E. coli associated with adherence may be important in metritis and PVD. Cytological endometritis and PVD are overlapping but largely distinct conditions, and there are emerging data that cervicitis exists both concurrent with and separate from endometritis. Much remains to be learned about what initiates and sustains harmful inflammation of the reproductive tract. Such information is necessary to develop effective treatments for the various forms of disease and, more importantly, to develop means to prevent endometritis and cervicitis. In particular, vaccination against specific uterine pathogens and interventions to modulate innate immune response appear to be important avenues for investigation. Presently, commonly recommended best management practices for cows in the transition period are likely to be helpful to mitigate the risk of reproductive disease.     

Reproductive tract defense and disease in postpartum dairy cows

This paper briefly reviews recent data and concepts on the development and mitigation of infection and inflammation in the reproductive tract of dairy cows during the first 2 mo after calving. The incidence of metritis is typically between 10 and 20%, of clinical endometritis or purulent vaginal discharge (PVD) approximately 15%, and of subclinical or cytological endometritis a further 15%. Worse postpartum negative energy balance is associated with more severe or prolonged uterine inflammation. Changes in feed intake, expression of genes for pro-inflammatory cytokines, notably interleukin (IL) 1, IL6 and IL8, circulating concentrations of beta-hydroxybutyrate (BHBA) or nonesterified fatty acids (NEFA), and innate immune function precede both metritis and endometritis by several weeks. Infections with Escherichia coli and Arcanobacterium pyogenes are associated with both metritis and PVD. There are new data to suggest that specific virulence factors in E. coli associated with adherence may be important in metritis and PVD. Cytological endometritis and PVD are overlapping but largely distinct conditions, and there are emerging data that cervicitis exists both concurrent with and separate from endometritis. Much remains to be learned about what initiates and sustains harmful inflammation of the reproductive tract. Such information is necessary to develop effective treatments for the various forms of disease and, more importantly, to develop means to prevent endometritis and cervicitis. In particular, vaccination against specific uterine pathogens and interventions to modulate innate immune response appear to be important avenues for investigation. Presently, commonly recommended best management practices for cows in the transition period are likely to be helpful to mitigate the risk of reproductive disease.     

Association between endometritis and endometrial cytokine expression in postpartum Holstein cows

The endometrium regulates the inflammatory response after infection by production and release of cytokines and chemokines. The objective was to compare gene expression of important pro-inflammatory (TNFα, IL-1β, IL-6) and anti-inflammatory (IL-10) cytokines, and the main neutrophil chemokine (IL-8), from calving to Week 7 after calving, in cows that developed endometritis and healthy control cows. Uterine biopsies were obtained at calving and at Weeks 1, 3, 5 and 7. Endometritis was evaluated at Week 5 by uterine lavage and cytology; cows with ≥ 10% neutrophils were considered to have endometritis. Real-time RT-PCR threshold values (Ct) were used to calculate the fold difference in gene expression, using the 2^−ddCt method, normalized to GAPDH and calibrated to the average dCt for all cows at calving. Serum IL-8 concentrations were measured with ELISA. The analysis included 28 cows (11 had endometritis) for the PCR data and 44 cows (20 had endometritis) for ELISA. Expression of the TNFα gene in uterine tissue was decreased in cows with endometritis compared to control cows at calving (P = 0.09) and at Week 1 (P = 0.05). Iterleukin-1β gene expression tended to be decreased (P = 0.08) in cows with endometritis compared to control cows at Week 1, but tended to be increased (P ≤ 0.10) at Weeks 5 and 7. Cows with endometritis had increased (P < 0.05) IL-6 gene expression at calving and at Week 7 compared to control cows. Interleukin-8 gene expression was increased (P = 0.03) in endometritic cows compared to control cows at Week 7. Uterine disease was not significantly associated with IL-10 gene expression. A lower local level of expression of pro-inflammatory cytokines in the endometrium soon after calving might impair activation of inflammation and clearance of bacteria, and lead to development of endometritis.     

Baogong decoction treats endometritis in mice by regulating uterine microbiota structure and metabolites

Endometritis is persistent inflammation caused by bacteria, which can lead to infertility. Although traditional Chinese medicine (TCM) has been used to treat endometritis, the underlying mechanism is still unclear. Here, Baogong Decoction (BGD), a TCM compound, was used to treat mouse endometritis induced by Escherichia coli (E. coli), and then 16S rRNA sequencing and non-targeted metabolomics were used to investigate the change of uterine microbiota and metabolomes in serum and uterine after BGD treatment. Finally, the therapeutic effect of potential metabolites for treating mouse endometritis screened by combined omics analyses was verified using pathological model. The results showed that BGD treatment could effectively treat endometritis associated with the increasing relative abundance of Firmicutes, Bacteroides, Lactobacillus and Lactococcus, and the decreasing relative abundance of Cupriavidus and Proteobacteria. 133 and 130 metabolites were found to be potential biomarkers in serum and uterine tissue respectively. In serum and tissues, dehydroepiandrosterone (DHEA) and catechol were significantly increased in the BGD treatment versus the inflammation group. Results of combined omics analyses demonstrated that DHEA was positively correlated with changes in microbiota. Results of pathological model demonstrated that DHEA could cure endometritis effectively associated with the decreasing infiltration of inflammatory cells and expression of inflammatory factors in the uterus. In summary, our results demonstrated that BGD could cure endometritis in mice by modulating the structure of the uterine microbiota and its metabolites, in which DHEA may be one of the main components of the therapeutic effect of BGD.     

Biodegradable estradiol microspheres do not affect uterine involution or characteristics of postpartum estrus in mares

Quarterhorse mares were used to investigate effects of estradiol-17beta on uterine involution, duration of estrus, interval to ovulation, and fertility achieved by breeding on the first postpartum estrus. On the day of foaling, mares were injected with biodegradable poly (DL-lactide) microspheres containing either 100 mg estradiol-17beta (25 mares) or no drug (27 mares). The treatment period was considered to last for 12 to 15 d. Estrus was determined by teasing mares (n=16) with a stallion. Ovulation was detected by transrectal ultrasonographic examination of ovaries (n=48). On Days 6, 11 and 16 post partum, transrectal ultrasonography was used to measure cross-sectional diameters of the uterine body, uterine horns, and fluid within the uterine lumen (n=28). Uteri were swabbed for bacteriologic culture, and uterine biopsies were obtained from the previously gravid uterine horn on Days 11 and 16 post partum, for assessment of endometritis and morphometric analysis of endometrial histioarchitecture (n=19). Twenty-two mares were bred on foal-heat, and pregnancy was determined by transrectal ultrasonography on 14 to 16 and 30 to 35 d after breeding. With only one exception (diameter of previously gravid uterine horn on Day 11), mean values for all measures of uterine involution did not differ between treatment groups (P > 0.05). No differences were detected between treatment group means for length of estrus or interval to ovulation (P > 0.05). No differences were detected between treatment group liklihoods for recovery of potential bacterial pathogens, presence of endometritis, or presence of intrauterine fluid at 11 or 16 d post partum (P > 0.05). Pregnancy rate of mares treated with estradiol (5 11 ; 45%) was not different from that of control mares (9 11 ; 82%; P > 0.05). Estradiol treatment did not hasten uterine involution, increase duration of estrus, delay ovulation, or increase fertility in these postpartum mares.