Endometrial Cytokine Research Articles

O-056 Can we tailor ART to endometriosis patients?

Abstract ART remains an effective treatment for endometriosis-associated infertility, although there is evidence that pregnancy rates are diminished in women with endometriosis compared with other etiologies of infertility. In this lecture, the literature relating to endometriosis-associated infertility will be evaluated and recommendations will be made on the management of patients both pre-ART and during ART in order to improve ART outcomes in women with endometriosis. Surgery as an adjuvant to ART appears to have a favorable effect in patients with minimal to mild endometriosis prior to IVF. However, this evidence is based on only one study and more research is needed. As deep endometriosis (DE) is usually accompanied by advanced intra-abdominal disease resulting in distortion of the pelvic anatomy and tubal dysfunction, it is not surprising that IVF is considered as first line treatment. Observational data are available on the outcomes of DE surgery regarding conception rates in infertile patients with endometriosis suggesting that surgery may increase natural pregnancy rates as well as improve IVF outcomes. However, randomized trials comparing IVF to DE surgery are non-existent, as DE surgery is still mainly performed for pain and reduced quality of life rather than for treating infertility. In order to improve IVF success rates in endometriosis, various pre-ART treatments have been suggested. The oldest one relates to the use of gonadotropin releasing hormone (GnRH) agonist prior to IVF. Currently there is uncertainty as to whether long-term GnRH agonist therapy is beneficial when compared to standard IVF/ICSI in endometriosis. In addition, there is no evidence to support the use of oral GnRH antagonists and oral contraceptives as pre-treatment prior to ART, but results of ongoing studies will determine further. More recent studies support defects in endometrial receptivity as a cause of IVF failure. In recent years a new marker for endometrial receptivity in endometriosis emerged: BCL6, a biomarker for endometrial inflammation as it stimulates endometrial cytokine expression. Prospective cohort data provide a proof of concept that high BCL6 expression is associated with adverse IVF outcomes in women with endometriosis and that patients with high BCL6 expression may benefit from medical and surgical treatment prior to IVF. In order to improve IVF success rates in endometriosis, various pre-ART treatments have been suggested. The oldest one relates to the use of gonadotropin releasing hormone (GnRH) agonist prior to IVF. Contrary to previous findings, there is currently uncertainty as to whether long-term GnRH agonist therapy is beneficial when compared to standard IVF in endometriosis. In addition, there is also no evidence to support the use of oral GnRH antagonists and oral contraceptives as pre-treatment prior to ART in endometriosis, but results of ongoing studies will determine further. It has been hypothesized that applying local endometrial injury might induce a beneficial effect on endometrial receptivity prior to ART. However, scratching the endometrium as well as infusing fluids (Lipiodol and ExEm gel) into the uterine cavity (uterine bathing) in endometriosis patients prior to ART did not improve IVF success. During ART, a specific protocol for ART in women with endometriosis cannot be recommended. Both GnRH agonist and antagonist protocols can be used. For ovarian stimulation, a higher dose of gonadotropins may be required in stage III-IV endometriosis due to a poorer ovarian response. There is insufficient evidence for the routine use of prophylactic antibiotics at the time of oocyte retrieval in patients with endometriosis, but their use is recommended in patients with endometrioma. Considering fertilization, there appears no added benefit in using ICSI over IVF in endometriosis unless male-factor infertility is present. Finally, there is insufficient evidence to recommend any particular luteal support in women with endometriosis undergoing ART.

Changes in interleukin-2, -4, -6 and -8 expression in the postovulatory sow endometrium after artificial insemination based on conceived or failed to conceive.

The establishment and maintenance of a pregnancy requires proper interaction between the endocrine and immune systems in the uterus. Therefore, it is crucial to understand how changes in endometrial cytokine levels facilitate reproduction. This study aimed to investigate how representative cytokines sequentially changed in the endometrium and whether conception could be attributed to these changes. In this study, artificial insemination was performed twice in 160 sows and ovulation was examined every 3 h using transrectal ultrasonography. Uterine endometrial tissues were obtained via repeated biopsies at 2, 4, 6, 8, 12, 16, and 20 h after ovulation and interleukin (IL)-2, IL-4, IL-6, and IL-8 expression was examined using real-time polymerase chain reaction. The conception rate was 91.9%. The IL-2 levels showed no differences in conception or time. The expression peaks of IL-4 and IL-6 were delayed in sows that failed to conceive within 4-6 h and 2 h, respectively, compared to those that did conceive. In sows that conceived, IL-8 was highest after 2 h, and no difference was observed at other time point, regardless of conception. In sows that failed to conceive, the increase in IL-8 levels might have been cancelled or terminated before the first sampling time. These results highlight the importance of timely increases and subsequent declines in the levels of some cytokines for the establishment of pregnancy. Differences in uterine capacity start just after ovulation; detection and correction of these deviations can improve the reproductive efficiency of sows.

Importance of Induction Endometritis and Vaginal Cytology in Rat Model: A Narrative Review Article

Introduction: Endometritis is a female reproductive disease characterized by the inflammation of the endometrial glandular and stromal tissues. It is usually occurred due to uterine contamination with infectious causes. Animal models of clinical endometritis are very important to prevent the incidence and treatment of endometritis. Vaginal cytology method is considered as a golden standard for determining the estrous cycle stage in female rats. The aim of this study was to induce endometritis in a rat model and determine the stages of the estrous cycle of this animal using vaginal cytology method in order to successfully induce this condition in this animal model.
 Conclusion: Inflammation changes the production of endometrial cytokines, which may result in menstrual disorders and decreased endometrial reception by impaired endometrial tissue dysfunction. Increased expression of specific cytokines genes such as IL-6, IL-8 and TNF-α can be used to detect the severity and degree of endometritis. Uterine infections are known as a result of damage to the defense mechanisms of the uterine tissue, which are caused by physiological changes in the postpartum period. Another change that occurs in the postpartum period is the increase in the production of reactive oxygen species. The imbalance between the production of reactive oxygen species and its clearance leads to the creation of oxidative stress conditions. On the other hand, there is a significant relationship between inflammatory diseases such as endometritis and oxidative stress. On other hand, by accurately determining the estrous cycle of rats by using vaginal cytology, endometritis can be well induced in this species.

Should the Treatment of Patients with Repeated Embryo Implantation Failure Be Adapted as a Function of the Endometrial Cytokine Profile? A Single-Center Experience.

Repeated embryo implantation failures (RIF) is a source of distress and frustration for patients and clinicians alike. Today's approaches for treating RIF are largely empirical and have limited effectiveness. The main causes of RIF are poor endometrial receptivity and poor-quality embryos. Recent studies have suggested the involvement of immune dysregulation due to an imbalance between T-helper (Th) 1 and Th2 cytokines; this opens up perspectives for treating women with RIF and increasing the implantation rate. We conducted an interventional, longitudinal, prospective cohort study of the impact of correcting the cytokine imbalance on the clinical pregnancy rate in women with RIF. Seventy-seven women with RIF underwent an endometrial biopsy during the implantation window. The cytokine profile was evaluated by studying the activation and maturation of uterine natural killer (uNK) cells, the IL-15/Fn-14 mRNA ratio (a biomarker of uNK activation/maturation), and the IL-18/TWEAK mRNA ratio (a marker of angiogenesis and the Th1/Th2 balance). Personalized treatment was initiated for women with an abnormal endometrial cytokine profile (hyper-activation or hypo-activation). We documented the clinical pregnancy rate after subsequent embryo transfers. In total, 72.7% (56/77) of patients had an abnormal endometrial cytokine profile (hyper-activation in 68.8% (n = 53) and hypo-activation in 3.9% (n = 3). After treatment (or not) as a function of the endometrial profile, the overall clinical pregnancy rate was 30.2%. Our results indicated a potential positive effect of appropriate treatment on the ongoing pregnancy rate in women with RIF, despite the small number of cases analyzed. The results must now be validated in randomized studies with larger numbers of well-characterized patients. By applying a previously published decision tree, this treatment approach could be implemented in clinics worldwide.

Endometrial cytokines in patients with and without endometriosis evaluated for infertility

To evaluate whether endometrial molecular profiles distinguish subsets of patients according to clinical characteristics, and to infer dysregulated immune networks, by measuring cytokines, chemokines, and growth factors in endometrial biopsy specimens from a cohort of infertile women with a high incidence of endometriosis. Prospective cohort study. Department of Gynecology at a university hospital. Patients undergoing laparoscopy for infertility assessment (n = 103). Endometrial biopsies were performed during surgery. Fertility outcome and clinical parameters were registered preoperatively and after 6 months. The concentrations of 48 factors in endometrial biopsy specimens were analyzed with respect to clinical status in univariate and multivariate frameworks. The concentrations of 44 factors from endometrial tissues of 74 patients were suitable for analysis. Although the tissue concentrations of interleukin (IL)15, IL-7, and interferon γ-induced protein (IP)-10 were individually lower in patients with endometriosis than in those without endometriosis, the differences were not significant after multiple comparison. However, multivariate modeling incorporating covariation showed separation between subsets of endometriotic and nonendometriotic patients, based predominantly on IP-10, monocyte chemoattractant protein-1, IL-16, and IL-18; this result was independent of cycle and fertility status. Analysis restricted to endometrial tissues from the secretory phase separated endometriotic and nonendometriotic patients by a combination of IL-15, IP-10, monocyte chemoattractant protein-1, IL-16, and IL-18. This combination suggests a uterine natural killer cell defect. We found no significant correlations between endometrial cytokines and fertility outcome. A molecular signature in endometrial tissue was able to distinguish endometriotic from nonendometriotic patients, implicating uterine natural killer cells in endometriosis.

Endometrial cytokine expression from clinically suspected genital tuberculosis patients at tertiary care hospitals in Dhaka

ObjectiveThe objective of this study was to measure gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) expression in endometrial tissue and/or aspirate from suspected genital tuberculosis patients with ectopic pregnancy and infertility in Bangladesh. MethodologyA total 78 women of clinically suspected genital tuberculosis patients were enrolled as study population. These patients underwent manual vaccum aspiration (MVA) procedure, and endometrial tissues and/or aspirates were collected. Ziehl -Neelsen staining (Z-N staining) and Lowen–Stein Jensen (L-J) culture were done to detect Mycobacterium. The study participants were categorized as genital tuberculosis positive cases, genital tuberculosis negative cases and presumptive for tuberculosis cases based on the case definition used in this study. TNF-α and IFN-γ were measured by ELISA. Statistical analysis was done using SPSS (version-22). ResultsOut of 78 participants, pro-inflammatory cytokines IFN-γ and TNF-α were significantly increased in TB positive patients than TB negative patients (p < 0.05). IFN-γ value of TB positive patients (41.26 ± 41.05) was higher than TB negative (22.94 ± 44.51) patients. TNF-α value (44.31 ± 64.22) of TB positive patients was higher than TB negative (15.86 ± 41.45) patients. IFN-γ and TNF-α value of presumptive for tuberculosis cases were not statistically significant. According to ROC analysis, cut off value for IFN-γ was 23.5 and for TNF-α was 10 with highest sensitivity and specificity of 66.7%, 89.3%, and 66.7% and 73.1% respectively. ConclusionIFN-γ and TNF-α were significantly higher in TB positive patients and it may act as a potential biomarker for diagnosis of genital tuberculosis.

Characteristics of the main links of immunity and endometrial cytokines in women with reproductive disorders

Characteristics of the main links of immunity and endometrial cytokines in women with reproductive disorders

Endometrial Cytokines in Women with Reproductive Disorders

The purpose of this research was to study changes in endometrial cytokine concentrations in women suffering from reproductive disorders with and without chronic endometritis (CE) to justify pathogenetic treatment. Methods and Results: The study included 100 women of reproductive age with reproductive disorders. Group 1 included 50 patients with reproductive disorders and CE; Group 2 included 50 patients with reproductive disorders and without CE. Later on, all patients were divided into the following subgroups: Sub1A (n=31), and Sub2A (n=16) with an isolated bacterial flora, Sub1B (n=19) and Sub2B (n=34) with the absence of bacterial flora. The control group consisted of 31 fertile women. Endometrial aspiration pipe biopsy was performed on days 4-9 of the menstrual cycle (middle proliferative phase) using a disposable intrauterine probe (Taizhou Kechuang Medical Apparatus Co., Ltd, China) followed by histological examination of endometrial tissue. Laboratory diagnostics for sexually transmitted infections (STIs) was performed using the bacterial culture method. For the diagnosis of viral infection (HPV, HSV, CMV), cervical samples were studied using PCR. If STIs were detected, the patients were excluded from further research. Ultrasound examination of the pelvic organs was performed using the Aloka-5500 device with a 7MHz vaginal probe in two-dimensional visualization mode. The concentration of cytokines (IL-1β, INF-γ, TNF-α, ILs-4,6,8,10) in the endometrium was determined using the Protein Contour test systems (Saint Petersburg) and Multiskan EX ELISA Analyzer (Germany). In both groups, reproductive disorders were accompanied by hypoprogesteronemia and relative hyperestrogenemia, significantly apparent in CE. We found a 3-fold increase in the level of tissue pro- and anti-inflammatory cytokines (IL-1β, IL-4,6,10, INF-γ), and a 4-fold increase in the level of TNF-α and IL-8 in Group 1, compared to the CG. In Group 2, we found a 1.4-fold increase in the levels of IL-1β and INF-γ, compared to the CG. In Sub 1a, the levels of IL-6 and IL-8 were significantly higher than in the control group. In Sub1A, the isolated bacterial flora caused a cytokine inflammatory response characterized by a significant increase in the concentration of INF-γ and TNF-α, compared to Sub2A and Sub2B (P&lt;0.05). In Sub1A, we found a tendency towards a decrease in the tissue levels of IL-4 compared to Sub1B and Sub2B; the IL-10 level was significantly lower than in Sub2B (P=0.0009) Conclusion: The results obtained in the present study showed the peculiarities of changes in cytokines at the level of endometrial tissue both in chronic inflammation of the endometrium and in its absence in women with reproductive disorders. The severity of the immune response is significantly higher in patients with CE, with the most significant change in the role of IL-10.

Embryonic Trophectoderm Secretomics Reveals Chemotactic Migration and Intercellular Communication of Endometrial and Circulating MSCs in Embryonic Implantation.

Embryonic implantation is a key step in the establishment of pregnancy. In the present work, we have carried out an in-depth proteomic analysis of the secretome (extracellular vesicles and soluble proteins) of two bovine blastocysts embryonic trophectoderm primary cultures (BBT), confirming different epithelial–mesenchymal transition stages in these cells. BBT-secretomes contain early pregnancy-related proteins and angiogenic proteins both as cargo in EVs and the soluble fraction. We have demonstrated the functional transfer of protein-containing secretome between embryonic trophectoderm and maternal MSC in vitro using two BBT primary cultures eight endometrial MSC (eMSC) and five peripheral blood MSC (pbMSC) lines. We observed that eMSC and pbMSC chemotax to both the soluble fraction and EVs of the BBT secretome. In addition, in a complementary direction, we found that the pattern of expression of implantation proteins in BBT-EVs changes depending on: (i) their epithelial–mesenchymal phenotype; (ii) as a result of the uptake of eMSC- or pbMSC-EV previously stimulated or not with embryonic signals (IFN-τ); (iii) because of the stimulation with the endometrial cytokines present in the uterine fluid in the peri-implantation period.

Intrauterine Infusion of TGF-β1 Prior to Insemination, Alike Seminal Plasma, Influences Endometrial Cytokine Responses but Does Not Impact the Timing of the Progression of Pre-Implantation Pig Embryo Development.

Simple SummaryAlthough endometrial immune regulation in pigs during the early preimplantation period is poorly documented, particularly under conditions of embryo transfer (ET), it is recognized that seminal plasma (SP) induces molecular changes in the reproductive tract, influencing numerous reproductive functions. A principal constituent of SP is the cytokine transforming growth factor β1 (TGF-β1), which has an important role in embryo development, pregnancy establishment, and progression. The present study evaluated different intrauterine infusion treatments at estrus (40 mL of SP, porcine TGF-β1 in an extender, or an extender alone (control)) by mimicking an ET scenario in so-called “donor” (inseminated) and “recipient” (uninseminated) sows. We investigated the effects of these treatments on day 6 embryo development (“donors”) and endometrial explants’ cytokine production (“donors” and “recipients”). SP infusion positively influenced embryo development compared with TGF-β1 or extender infusions. Infusion treatments differentially affected endometrial cytokine production, with the effects being stronger in “donors” than in “recipients.” Increased knowledge of the effects of SP or some of its active components on the female immune system may help to develop strategies for increasing the reproductive efficiency for the benefit of pig ET.Seminal plasma (SP) in the female genital tract induces changes that affect multiple reproductive processes. One of the active components in SP is the transforming growth factor β1 (TGF-β1), which has major roles in embryo development and pregnancy. Embryo transfer (ET) technology is welcomed by the pig industry provided that embryo quality at embryo collection as well as the fertility and prolificacy of the recipients after the ET is increased. This study evaluated different intrauterine infusion treatments at estrus (40 mL of SP, TGF-β1 cytokine in the extender, or the extender alone (control)) by mimicking an ET scenario in so-called “donor” (inseminated) and “recipient” (uninseminated) sows. On day 6 (day 0—onset of estrus), all “donors” were laparotomized to determine their pregnancy status (presence and developmental stage of the embryos). In addition, endometrial explants were collected from pregnant “donors” and cyclic “recipients,” incubated for 24 h, and analyzed for cytokine production. SP infusions (unlike TGF-β1 infusions) positively influenced the developmental stage of day 6 embryos. Infusion treatments differentially influenced the endometrial cytokine production, mainly in donors. We concluded that SP infusions prior to AI not only impacted the porcine preimplantation embryo development but also influenced the endometrial cytokine production six days after treatment, both in donors and recipients.

Cytokine imbalance at materno-embryonic interface as a potential immune mechanism for recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a prominent reproductive disease that distresses about 2%-5% of couples. RPL is the loss of two or more successive spontaneous pregnancies prior to the 20th week of embryo development. The commencement of pregnancy necessitates implantation of the embryo into responsive maternal decidua synchronized with the process of placentation, decidual and myometrial trophoblast incursion as well as refashioning of spiral blood arteries of uterus. The collapse of any of the processes fundamental for pregnancy success may result into an array of pregnancy problems including spontaneous pregnancy loss. Endometrium of human female manufactures an extensive range of cytokines during the proliferative and secretory stage of the menstrual cycle. These endometrial cytokines are thought as major players for making the uterus ready for embryo implantation and placental development during pregnancy. Decidual cytokines regulate the invasion of trophoblast and remodeling of spiral arteries as well as take part in immune suppression to accomplish the pregnancy. Deterrence of maternal rejection of embryo needs a regulated milieu, which takes place essentially at the embryo-maternal interface and the tissues of the uterus. The reasons of RPL remain anonymous in a large number of cases that lead to difficulties in management and severe trauma in couples. Cytokine modulatory therapies have been shown promising for preventing RPL. Further study of novel factors is wanted to establish more effective RPL treatment protocols. The present study aims to review the outcome of cytokine breach at materno-embryonic interface and the efficacy of cytokine modulatory therapies in RPL.

Subclinical endometritis and postpartum ovarian resumption in respect to TNF-α, IL-8 and CRP in Egyptian buffaloes.

The study was carried out to find the relation between subclinical endometritis (SCE) and postpartum (pp.) ovarian resumption as well as to evaluate serum and endometrial TNF-α, IL-8 and serum CRP in buffaloes with and without SCE. Thirty-nine pluriparous buffaloes at the 3rd (W3), 5th (W5) and 7th (W7) week pp. were involved in this experiment. The parity of the buffaloes ranged from 4 to 8 with an average 5.8±0.2. Subclinical endometritis was diagnosed by the percentage of polymorphonuclear cells (PMNs) in uterine cytology obtained from endometrial cytobrush at W5 and W7. The cut-off point of PMNs% in buffaloes for SCE was ≥ 6% at W5 or ≥ 4% at W7. According to PMNs%, buffaloes were divided into SCE group (n=27) and non-SCE group (n=12). Ovarian cyclicity was monitored by rectal palpation, ultrasonography and progesterone assay at W3, W5 and W7. Serum and endometrial TNF-α, IL-8 and serum CRP were estimated at W5 and W7. Buffaloes with SCE (55.6%) showed delayed ovarian activity as compared to non-SCE (16.7%) animals (P=0.036). Significant increase in serum cytokines and CRP levels were detected at W5 (P ˂0.05) and W7 (P <0.01) in SCE buffaloes as compared to non-SCE. Endometrial levels of cytokines were significantly (P ˂0.05) elevated in SCE buffaloes. Serum and endometrial cytokines showed significant positive correlation. Furthermore, levels of TNF-α, IL-8 and CRP exhibited significant positive correlation with PMNs%. In conclusion, SCE delayed postpartum ovarian cyclicity in buffaloes. Moreover, TNF-α, IL-8 and CRP assessments could be efficient tools in prediction of SCE in buffaloes.

Endometrial cytokine levels in recurrent pregnancy loss and implantation failure

Endometrial cytokine levels in recurrent pregnancy loss and implantation failure

Role of endometrial cytokines of the female genital tract tuberculosis in the context of infertility

BACKGROUND: Nowadays, one of the most common vulnerable sites of extrapulmonary tuberculosis is female genital tract tuberculosis (FGTB) leading to infertility. As FGTB produce clinical symptom quite late, its detection is very difficult to the health-care providers and according to some experts in this field; FGTB has no confirmatory investigation procedure. FGTB can cause other form of reproductive failure through ectopic pregnancy, tubal block, and implantation failure. Their presence may alter the cytokines level in endometrium. METHODS: A total of 300 cases in our clinic had undergone polymerase chain reaction (PCR) for detection of tubercle bacillus (TB-PCR). Among of them, 91 individuals fulfilling all inclusion and exclusion criteria were included in this study. In our study, we measured cytokines, two from pro-inflammatory group (interleukin-6 [IL-6] and IL-10) and three from inflammatory group (IL-2, interferon gamma [IFNγ], and tumor necrosis factor alpha [TNFα]). RESULTS: Out of 91 participants, 45 (49.46%) cases were TB-PCR positive, and 46 (50.55%) cases were TB-PCR negative. It has been observed that the value of IL-10 and TNFα did not fit any statistical parameter. The result showed that pro-inflammatory indicators IL-6 and inflammatory indicators IL-2 and IFNγ had significant different values between TB-PCR- positive and TB-PCR-negative groups. P value of this cytokines has statistically significant. CONCLUSION: From our study, we conclude that cytokine study was undertaken, of which IFNγ showed a possibility to become an important clinical indicator of endometrial hostility followed by IL-2.

Molecular analysis of endometrial inflammation in preterm birth.

Spontaneous preterm birth (sPTB) represents the 35%-45% of all preterm birth (PTB) cases and its etiology is unknown. We investigated if the expression level of endometrial cytokines and angiogenetic factors is related to the onset of sPTB.Endometrial tissues from non-pregnant women who experienced sPTB and from non-pregnant women who did not experience sPTB were collected and examined for their expression profile. With this aim, the PCR Array analysis was performed and data were confirmed by Real-Time PCR. Differential gene expression measurements (pathological vs control tissues) showed a significant up-regulation for genes codifying for two angiogenetic factors known as connective tissue growth factor (CTGF), and coagulation factor III (F3). An increased level of expression was detected both for tyrosine kinase endothelial (TEK) and for transforming growth factor beta 2 (TGF-β2) genes but without reaching the statistical significance. The expression level of interleukin 10 receptor alpha (IL10RA) gene was slightly decreased in pathological group compared to control one but, as well as forTEK and TGF-β2 measurements, without reaching the statistical significance. Our work is the first to correlate the imbalance in endometrial district of non -pregnant women with sPTB. These data could suggest a new point of view whence to read sPTB. We need additional clinical and biological studies to clarify sPTB pathogenesis.

The effect of select seminal plasma proteins on endometrial mRNA cytokine expression in mares susceptible to persistent mating-induced endometritis.

In the horse, breeding induces a transient endometrial inflammation. A subset of mares are unable to resolve this inflammation, and they are considered susceptible to persistent mating-induced endometritis PMIE Select seminal plasma proteins cysteine-rich secretory protein-3 (CRISP-3) and lactoferrin have been shown to affect the innate immune response to sperm in vitro. The objective of this study was to determine whether the addition of CRISP-3 and lactoferrin at the time of insemination had an effect on the mRNA expression of endometrial cytokines in susceptible mares after breeding. Six mares classified as susceptible to PMIE were inseminated during four consecutive oestrous cycles with treatments in randomized order of: 1mg/ml CRISP-3, 150μg/ml lactoferrin, seminal plasma (positive control) or lactated Ringer's solution (LRS; negative control) to a total volume of 10ml combined with 1 × 109 spermatozoa pooled from two stallions. Six hours after treatment, an endometrial biopsy was obtained for qPCR analysis of selected genes associated with inflammation (pro-inflammatory cytokines interleukin (IL)-1β, IL-8, tumour necrosis factor (TNF)-α, interferon (INF)-γ, anti-inflammatory cytokines IL-1RN and IL-10, and inflammatory-modulating cytokine IL-6). Seminal plasma treatment increased the mRNA expression of IL-1β (p=.019) and IL-8 (p=.0068), while suppressing the mRNA expression of TNF (p=.0013). Lactoferrin also suppressed the mRNA expression of TNF (p=.0013). In conclusion, exogenous lactoferrin may be considered as one modulator of the complex series of events resulting in the poorly regulated pro-inflammatory response seen in susceptible mares.

The presence of heparins during decidualization modulates the response of human endometrial stromal cells to IL-1β in vitro.

The aim of this paper is to study the impact of heparin on the response of human endometrial stromal cells (ESCs) to interleukin (IL)-1β during decidualization in vitro. ESCs were isolated from hysterectomy specimens of premenopausal women undergoing hysterectomy for benign reasons; decidualized in vitro and incubated in parallel with unfractionated heparin or tinzaparin; and stimulated with IL-1β at days 0, 3, 6, and 9 during decidualization. IL-6, IL-11, and leukemia inhibitory factor (LIF) were analyzed using ELISAs and real-time RT-PCR. Cell viability was determined by a fluorometric assay. IL-1β dose-dependently stimulated IL-6, IL-11, and LIF in distinct patterns in ESCs during decidualization. Unfractionated heparin as well as tinzaparin attenuated the IL-1β-mediated induction of IL-6, IL-11, and LIF on protein and messenger RNA (mRNA) levels. The relative effects of heparin and tinzaparin were getting more pronounced during the time course of decidualization. Unfractionated heparin and the low molecular weight heparin tinzaparin have modulating effects on IL-1β-induced endometrial cytokines of the IL-6 family during decidualization. These effects of heparins beyond their classical anti-coagulatory properties might have implications on the regulation of endometrial receptivity and early implantation.

The Effect of Cysteine-Rich Secretory Protein-3 and Lactoferrin on Endometrial Cytokine mRNA Expression After Breeding in the Horse

The equine uterus undergoes a transient innate immune response after breeding, also known as mating-induced endometritis. The deposition of spermatozoa triggers the expression of pro-inflammatory cytokines, which results in the migration of polymorphonuclear neutrophils (PMNs) into the endometrium and the uterine lumen. Select seminal plasma proteins, specifically cysteine-rich secretory protein 3 (CRISP-3) and lactoferrin, have been shown to affect the activity of the PMNs, either by suppressing (CRISP-3) or promoting (lactoferrin) the phagocytosis of spermatozoa based on their viability in vitro. Conjointly, many components of inseminate, including seminal plasma, bacteria, and spermatozoa itself, have shown to have an effect on the expression of endometrial cytokines after breeding. The objective of this study was to determine if select proteins affect the mRNA expression of endometrial cytokines after insemination. Six mares were bred during four consecutive estrous cycles with treatments in randomized order of: 1mg/mL CRISP-3, 150 ug/mL lactoferrin, seminal plasma, or Lactated Ringer’s Solution (LRS) to a total volume of 10 mL combined with 1×109 progressively motile spermatozoa pooled from two stallions. Six hours after treatment, an endometrial biopsy was obtained for qPCR analysis. No treatment effects were found for the mRNA expression of IL-1β, IL-6, IL-8, IL-10, TNFα, and IFNγ, while lactoferrin significantly suppressed the mRNA expression of IL-1RN when compared to LRS. In conclusion, the seminal plasma proteins CRISP-3 and lactoferrin have minimal effect on the expression of select endometrial cytokines at 6 hours post breeding.

Our current understanding of the pathophysiology of equine endometritis with an emphasis on breeding-induced endometritis

Equine endometritis is characterized by the expression of pro- and anti- inflammatory cytokines and an influx of polymorphonuclear neutrophils (PMNs) into the uterus. Mares resistant to persistent endometritis clear the inflammation within 24–36h after exposure to microorganisms or semen. These mares have a rapid increase of pro-inflammatory cytokines and an upregulation of inflammatory modulating cytokines within 6h after exposure to inflammatory challenge. In conjunction with effective uterine contractions, these events are believed to be responsible for the transient nature of the inflammation. In contrast, mares that are susceptible to persistent endometritis fail to clear the inflammation in a timely fashion. They have an imbalanced endometrial mRNA expression of pro- and anti-inflammatory cytokines, and have also been shown to suffer from an accumulation of intraluminal nitric oxide, which may be related to impaired myoelectrical activity and delayed uterine clearance. As a consequence, these mares establish a chronic inflammation, which interferes with the establishment of pregnancy. Recent studies on endometrial cytokine expression in resistant and susceptible mares have revealed information that suggest an underlying immunologic basis for susceptibility to persistent endometritis. However, the inflammatory pathways have yet not been fully studied, and a relationship between cytokine expression, nitric oxide, and myometrial contractions has not been established. In addition, seminal plasma has been shown to modulate breeding induced inflammation, but the molecular basis of the modulation is not understood. A holistic approach appears to be needed to better understand the characteristics of inflammatory pathways and ultimately the pathophysiology of the disease.

TLR4 Signaling Is a Major Mediator of the Female Tract Response to Seminal Fluid in Mice.

Seminal fluid interacts with epithelial cells lining the female reproductive tract to induce expression of proinflammatory cytokines and chemokines, initiating immune tolerance mechanisms to facilitate pregnancy. TGFB cytokines are key signaling agents in seminal plasma but do not fully account for the female response to seminal fluid. We hypothesized that additional molecular pathways are utilized in seminal fluid signaling. Affymetrix microarray was employed to compare gene expression in the endometrium of mice 8 h after mating with either intact males or seminal fluid deficient (SVX/VAS) males. Bioinformatics analysis revealed TLR4 signaling as a strongly predicted upstream regulator activated by the differentially expressed genes and implicated TGFB signaling as a second key pathway. Quantitative PCR and microbead data confirmed that seminal fluid induces endometrial synthesis of several TLR4-regulated cytokines and chemokines, including CSF3, CXCL1, CXCL2, IL1A, IL6, LIF, and TNF. In primary uterine epithelial cells, CSF3, CXCL1, and CXCL2 were strongly induced by the TLR4 ligand LPS but suppressed by TGFB, while IL1A, TNF, and CSF2 were induced by both ligands. TLR4 was confirmed as essential for the full endometrial cytokine response using mice with a null mutation in Tlr4, where seminal fluid failed to induce endometrial Csf3, Cxcl2, Il6, and Tnf expression. This study provides evidence that TLR4 contributes to seminal fluid modulation of the periconception immune environment. Activation of TLR4 signaling by microbial or endogenous components of seminal fluid is thus implicated as a key element of the female tract response to seminal fluid at the outset of pregnancy in mice.