Endometrial mRNA expression of matrix metalloproteinases, their tissue inhibitors and cell adhesion molecules in unexplained infertility and implantation failure patients

Cytokine and chemokine profiles in women with endometriosis, polycystic ovary syndrome, and unexplained infertility

Numerous factors (including immunological, congenital, hormonal, and morphological disorders) can lead to infertility. In this regard, 3 specific diseases associated with infertility are discussed in this review study (i.e., polycystic ovary syndrome [PCOS], endometriosis [EMS], and unexplained infertility [UI]). PCOS is a common endocrine disorder characterized by chronic low-grade inflammation, and EMS is a benign disease characterized by the presence of ectopic endometrial tissue. UI refers to couples who are unable to conceive for no known reason. Conception and pregnancy are significantly affected by the immune system; in this regard, chemokines and cytokines play important roles in the regulation of immune responses. Patients with PCOS, EMS, and UI have altered cytokine and chemokine profiles, suggesting that dysregulation of these molecules may contribute to infertility in these conditions. Accordingly, the issue of infertility is addressed in this review study, a condition that affects approximately 16% of couples worldwide.

Progesterone-mediated immunoregulation of cytokine signaling by miRNA-133a and 101-3p in Chlamydia trachomatis-associated recurrent spontaneous abortion

miRNAs regulate the expression of various genes involved in cellular and metabolic pathways in pregnancy related complications including recurrent spontaneous abortion (RSA). Modulation of progesterone and associated pro-inflammatory cytokines by miRNAs in Chlamydia trachomatis-associated RSA is still under investigation. Present study aimed to evaluate the expression/correlation of serum-circulating miRNAs-133a, 101-3p, 320b, 146b-5p, 24, 559, progesterone and few cytokines in C. trachomatis-positive spontaneous aborters. Non-heparinized blood and urine was collected from 120 patients with history of RSA (Group I) and 120 patients with ≥ 2 successful deliveries (Group II) attending Department of Obstetrics and Gynecology, Safdarjung hospital, New Delhi, India. C. trachomatis detection was performed by PCR and chlamydial load by real time PCR. Progesterone concentration was estimated by ELISA. miRNAs and cytokine expression was studied by quantitative real-time PCR and correlated with progesterone expression. Twenty six patients were found to be positive for C. trachomatis. miRNAs- 133a, 101-3p showed maximum upregulation in infected versus control patients. miRNA expression showed positive correlation with chlamydial load. Progesterone concentration showed significant decrease while cytokines (IL-6, IFN-γ, TNF-α) were significantly upregulated in C. trachomatis-positive patients. Positive correlation was observed between expression of miRNAs-133a and 101-3p and cytokines while negative correlation was observed with progesterone in infected RSA patients. Correlation between progesterone and cytokines was found to be significantly negative in infected RSA patients. Although further validation is required, the study concludes that miR-133a and 101-3p are of clinical importance and have a role in immunoregulation of progesterone and cytokines in infection associated RSA.

Identification of potential quality markers of Zishen Yutai pill based on spectrum-effect relationship analysis

Introduction: The current quality evaluation of traditional Chinese medicine (TCM) is difficult to attribute to clinical efficacy due to the complexity of TCM. Zishen Yutai pill (ZYP), a well-known traditional Chinese patent medicine, has been widely used to prevent recurrent miscarriage and treat threatened abortion. However, the chemical components of ZYP are unknown, and there is no convincing quality control method applied on ZYP. Although ZYP has been found to promote endometrial receptivity and treat impending abortion, the substantial basis of the therapeutic effects is unclear. The aim of this study was to clarify the quality markers correlated with the potential medicinal activities and provide a theoretical foundation for scientific quality control and product quality improvement of ZYP. Methods: The chemical constituents of ZYP were comprehensively analyzed by offline two-dimensional liquid chromatography-mass spectrometry (2DLC-LTQ-Orbitrap-MS). The efficacy of the 27 ZYP orthogonal groups was investigated using the HTR-8/SVneo oxidative damage model and migration model in vitro, as well as the endometrial receptivity disorder mouse model and premature ovarian failure mouse model in vivo. Based on the efficacy and mass spectral results, spectrum-effect relationship analysis was used to identify the chemical components with corresponding pharmacological activities. Results: A total of 589 chemical components were found in ZYP, of which 139 were not identified in the literature. The potential quality markers for ZYP were successfully identified through orthogonal design and spectrum-effect relationship analysis. By combining mass spectrum data and pharmacological results of 27 orthogonal groups, 39 substances were identified as potential quality markers. Conclusion: The approaches used in this study will provide a feasible strategy for the discovery of quality markers with bioactivity and further investigation into the quality evaluation of TCM.

Gene profiling reveals the role of inflammation, abnormal uterine muscle contraction and vascularity in recurrent implantation failure

Objective: Recurrent implantation failure (RIF) is now disturbing numerous infertile couples accepting assisted reproductive technology (ART). And the endometrial factors are crucial causes of recurrent implantation failure. However, its mechanism is still unclear. Thus, the aim of this study is to identify altered biologic processes in endometrium that may contribute to recurrent implantation failure. Methods: We recruited two microarray datasets (GSE103465, GSE111974) from Gene Expression Omnibus database (GEO), which contain endometrium from RIF and normal women during implantation period. Using the online tools GEO2R and Venny, we identified Differentially Expressed Genes (DEGs) of selected datasets, and obtained common DEGs. Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) and BioCatar pathway enrichment were conducted with Enrichr platform, "ssgsea" and "ggplot2" package of RStudio. PPI networks and hub gene related TF-gene interaction and TF-miRNA co-regulation networks were built via online tools STRING and NetworkAnalyst. Immune infiltration analysis was performed by CIBERSORT platform. Recurrent implantation failure subgroup identification was achieved through "ConsensusClusterPlus," "tsne," "ssgsea", and "ggpubr" package in RStudio. Diagnostic characteristic ROC curves were constructed via "pROC" and "ggplot2" package of RStudio. Enrichr platform was utilized to find drugs targeting hub genes. Results: 26 common DEGs were confirmed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes/BioCarta analysis determined common DEGs were mainly enriched in inflammation associated pathways including TNF, NF-κB, IL-4, IL-10, IL-6, and TGF-β signaling pathways. Five hub genes (PTGS2, VCAM1, EDNRB, ACTA2, and LIF) and related TF-gene and TF-miRNA interactions were identified. Immune infiltration analysis indicated the importance of macrophage M2 in recurrent implantation failure patients. Importantly, subgroup identification analysis highlighted that recurrent implantation failure patients can be divided into two subgroups with different phenotypes. Moreover, the ROC curves and drugs may provide new diagnostic and therapeutic thought for recurrent implantation failure.

The role of extracellular matrix on unfavorable maternal–fetal interface: focusing on the function of collagen in human fertility

Extracellular matrix (ECM) is characterized as widespread, abundant, and pluripotent. Among ECM members, collagen is widely accepted as one of the most prominent components for its essential structural property that can provide a scaffold for other components of ECM and the rich biological functions, which has been extensively used in tissue engineering. Emerging evidence has shown that the balance of ECM degradation and remodeling is vital to regulations of maternal–fetal interface including menstrual cycling, decidualization, embryo implantation and pregnancy maintenance. Moreover, disorders in these events may eventually lead to failure of pregnancy. Although the improvement of assisted conception and embryo culture technologies bring hope to many infertile couples, some unfavorable outcomes, such as recurrent implantation failure (RIF), recurrent pregnancy loss (RPL) or recurrent miscarriage (RM), keep troubling the clinicians and patients. Recently, in vitro three-dimensional (3D) model mimicking the microenvironment of the maternal–fetal interface is developed to investigate the physiological and pathological conditions of conception and pregnancy. The progress of this technology is based on clarifying the role of ECM in the endometrium and the interaction between endometrium and conceptus. Focusing on collagen, the present review summarized the degradation and regulation of ECM and its role in normal menstruation, endometrium receptivity and unsatisfying events occurring in infertility treatments, as well as the application in therapeutic approaches to improve pregnancy outcomes. More investigations about ECM focusing on the maternal–fetal interface interaction with mesenchymal stem cells or local immunoregulation may inspire new thoughts and advancements in the clinical application of infertility treatments.

Graphical abstract

Potential innate immunity-related markers of endometrial receptivity and recurrent implantation failure (RIF)

The successful implantation of the embryo into a receptive endometrium is essential for the establishment of a viable pregnancy while recurrent implantation failure (RIF) is a real challenge in assisted reproduction. The maternal innate immune system, specifically the Toll-like receptors (TLRs), are involved in maintaining immunity in the female reproductive tract (FRT) required for fertility. In this study, we aimed to investigate the importance of innate immunity-related gene expression in the regulation of human fertility and as a prediction of potential outcome of in vitro fertilization - embryo transfer (IVF-ET), thus, we assessed the gene expression levels of TLR signalling molecules using quantitative real-time PCR between endometrial biopsies of healthy fertile women, and the patients experiencing RIF. Interestingly, our results showed that, TRIB2 and TLR9 genes were differentially expressed between the endometrial biopsies of healthy women and those with RIF. However, comparing expression levels of same genes between pre-receptive and receptive healthy endometrial biopsies showed different genes (ICAM1, NFKBIA, VCAM1, LIF, VEGFB, TLR5) had significantly altered expression, suggesting their involvement in endometrial receptivity. Thus, further investigations will enable us to better understand the role of these genes in the biology of FRT and as a possible target for the improvement of infertility treatments and/or development of non-hormonal contraception.

Mating to Intact, but Not Vasectomized, Males Elicits Changes in the Endometrial Transcriptome: Insights From the Bovine Model

An appropriate female reproductive environment is essential for pregnancy success. In several species, including mice, pigs and horses, seminal plasma (SP) components have been shown to modulate this environment, leading to increased embryo viability and implantation. Due to the characteristics of mating in the aforementioned species, SP comes into direct contact with the uterus. However, it is questionable whether any SP reaches the uterus in species that ejaculate inside the vagina, such as humans and cattle. Hence, we hypothesized that sperm, perhaps acting as a vehicle for SP factors, play a more important role in the modulation of the maternal uterine environment in these species. In addition, changes elicited by SP and/or sperm may originate in the vagina and propagate to more distal regions of the female reproductive tract. To test these hypotheses, a bovine model in which heifers were mated to intact or vasectomized bulls or were left unmated was used. RNA-sequencing of endometrial samples collected 24 h after mating with a vasectomized bull did not reveal any differentially expressed genes (DEGs) in comparison with control samples. However, the endometrium of heifers mated with intact bulls exhibited 24 DEGs when compared to heifers mated with vasectomized bulls, and 22 DEGs when compared to unmated control heifers. The expression of a set of cytokines (IL6, IL1A, IL8, and TNFA) and candidate genes identified in the endometrial RNA-sequencing (PLA2G10, CX3CL1, C4BPA, PRSS2, BLA-DQB, and CEBPD) were assessed by RT-qPCR in the vagina and oviductal ampulla. No differences in expression of these genes were observed between treatments in any region. However, mating to both intact and vasectomized bulls induced an increase in IL1A and TNFA expression in the vagina compared to the oviduct. These data indicate that sperm, but not secretions from the accessory glands alone, induce modest changes in endometrial gene expression after natural mating in cattle. However, it is not clear whether this effect is triggered by inherent sperm proteins or SP proteins bound to sperm surface at the time of ejaculation.

Differential gene expression in bovine endometrial epithelial cells after challenge with LPS; specific implications for genes involved in embryo maternal interactions

Lipopolysaccharide (LPS) expressed on the surface of Gram-negative bacteria activates pro-inflammatory pathways, dys-regulates the function of endometrial cells and is a key player in the mechanisms involved in endometritis. This study aimed to investigate the effects of LPS on bovine endometrial epithelial cells (bEEC) from whole transcriptome with a special focus on genes involved in embryo-maternal interactions. Following in vitro culture, bEEC from three cows were exposed to 0, 2, and 8 μg/mL LPS for 24h. RNA samples extracted at 0 and 24 hours were analyzed by RNA sequencing (RNA-seq). At 24h, 2035 differentially expressed genes (DEGs) were identified between controls and samples treated with 2 μg/mL LPS. Gene ontology analysis showed that over-expressed DEGs were associated to immune response, response to stress and external stimuli, catalytic activity, and cell cycle. Genes associated with cell membrane and cell adhesion pathways were under-expressed. LPS induced changes in expression of specific genes related to embryo-maternal interactions including under-expression of eight members of the cadherin superfamily, over-expression of six members of the mucin family, and differential expression of a large set of genes binding the above molecules and of more than 20 transcripts coding for cytokines and their receptors. Type I interferon-τ dependent genes were also over-expressed. From a sub-set of 19 genes, (biological replicates of bEEC from cows taken at time 6 (n = 3), 24 (n = 6) and 48 hours (n = 3), and 2 technical replicates per sample) differential gene expression was confirmed by RT²-qPCR (r² between fold changes at 24 hours by RT²-qPCR and RNA-seq = 0.97). These results indicate that LPS affects the function of bEEC in many ways by differential transcription, glycolytic metabolism and oxidative stress. Many transcriptomic signatures related to implantation and embryo maternal interactions were strongly affected by LPS. These results pave the way for further studies to investigate the duration of these changes and their possible impact on endometrial function and fertility.

Dysregulation of collagen expression in peri-implantation endometrium of women with high ovarian response

AIM

To analyze the effects of high ovarian response on endometrial collagen synthesis and related gene expression during the peri-implantation period in patients undergoing in vitro fertilization-embryo transfer.

METHODS

Peripheral blood and endometrial biopsies were obtained from infertile women on day 6 after oocytes retrieval or ovulation in 16 stimulated cycles (SC) and 16 natural cycles (NC) respectively. Serum estrogen (E₂ ), progesterone (P₄ ), histological staging, endometrial collagen, matrix metalloproteinases (MMP2, 9) and tissue inhibitors of metalloproteinases (TIMP1, 3) were assayed.

RESULTS

Serum levels of both E₂ and P₄ were significantly higher in the SC group than those in the NC group. All endometrial samples were in the secretory phase. The collagen in the stroma of the SC group was more dense and higher than that in the NC group. MMP2 and MMP9 were detected significantly lower in the SC group than those in the NC group, while TIMP1 and TIMP3 were significantly higher. MMP2, 9 expressions are increased by estrogen and reduced by progesterone in dose-dependent manner through estrogen receptor and progesterone receptor. Correspondingly, TIMP1, 3 expressions decreased by estrogen dose-dependently while progesterone played the opposite role.

CONCLUSION

High levels of P₄ could stimulate excessive synthesis of collagen in peri-implantation endometrium of women with high ovarian response, and the mechanisms may be related to the decrease of MMP2, 9 and the increase of TIMP1, 3 through P₄ receptor.

Does endometrial scratching increase the rate of spontaneous conception in couples with unexplained infertility and a good prognosis (Hunault > 30%)? Study protocol of the SCRaTCH-OFO trial: a randomized controlled trial

Background

In the Netherlands, couples with unexplained infertility and a good prognosis to conceive spontaneously (i.e. Hunault > 30%) are advised to perform timed intercourse for at least another 6 months. If couples fail to conceive within this period, they will usually start assisted reproductive technology (ART). However, treatment of unexplained infertility by ART is empirical and can involve significant burdens. Intentional endometrial injury, also called ‘endometrial scratching’, has been proposed to positively affect the chance of embryo implantation in patients undergoing in vitro fertilization (IVF). It might also be beneficial for couples with unexplained infertility as defective endometrial receptivity may play a role in these women. The primary aim of this study is to determine whether endometrial scratching increases live birth rates in women with unexplained infertility.

Method

A multicentre randomized controlled trial will be conducted in Dutch academic and non-academic hospitals starting from November 2017. A total of 792 women with unexplained infertility and a good prognosis for spontaneous conception < 12 months (Hunault > 30%) will be included, of whom half will undergo endometrial scratching in the luteal phase of the natural cycle. The women in the control group will not undergo endometrial scratching. According to Dutch guidelines, both groups will subsequently perform timed intercourse for at least 6 months. The primary endpoint is cumulative live birth rate. Secondary endpoints are clinical and ongoing pregnancy rate; miscarriage rate; biochemical pregnancy loss; multiple pregnancy rate; time to pregnancy; progression to intrauterine insemination (IUI) or IVF; pregnancy complications; complications of endometrial scratching; costs and endometrial tissue parameters associated with reproductive success or failure. The follow-up duration is 12 months.

Discussion

Several small studies show a possible beneficial effect of endometrial scratching in women with unexplained infertility trying to conceive naturally or through IUI. However, the quality of this evidence is very low, making it unclear whether these women will truly benefit from this procedure. The SCRaTCH-OFO trial aims to investigate the effect of endometrial scratching on live birth rate in women with unexplained infertility and a good prognosis for spontaneous conception < 12 months.

Trial registration

NTR6687, registered August 31st, 2017.

Protocol version

Version 2.6, November 14th, 2018.

Does the dysregulation of matrix metalloproteinases contribute to recurrent implantation failure?

INTRODUCTION

The progress in in vitro fertilization (IVF) techniques for infertility management has led to the investigation of embryo implantation site proteins such as Matrix metalloproteinases (MMPs), which may have a key role in embryo-endometrium crosstalk and in the molecular mechanisms of the embryo implantation. Areas covered: Numerous studies have generated much information concerning the relation between the different proteins at the site of implantation such as cytokines, growth factors, adhesion molecules and MMPs. However, the exact role of the MMPs in embryo implantation and the impact of their dysregulation in recurrent implantation failure have yet to be characterized. Expert commentary: The proteomic investigation of the MMPs and their molecular pathways may enable scientists and clinicians to correct this dysregulation (via appropriate means of prevention and treatment), better manage embryo transfer during IVF cycles, and thus increase the ongoing pregnancy rate.

Intrauterine exosomes are required for bovine conceptus implantation

Exosomes, extracellular vesicles, are present in uterine flushing fluids (UFs), which are involved in conceptus-endometrial interactions during peri-implantation periods. Despite several studies on intrauterine exosomes conducted, the roles conceptus and endometrial exosomes play during peri-implantation periods have not been well characterized. To investigate the effect of bovine intrauterine exosomes on conceptus implantation, exosomes isolated from bovine UFs during peri-implantation periods were subjected to global protein analysis. The analysis detected 596 exosomal proteins, including ruminants' pregnancy recognition factor IFNT, and 172 differentially expressed proteins with more than 1.5-fold changes in UFs on days 17, 20 and 22 pregnancy (day of conceptus implantation is initiated on days 19-19.5). Treatment of primary bovine endometrial epithelial cells with exosomes from day 17 UFs up-regulated the expression of apoptosis-related genes, and treatment with exosomes from day 20 and 22 UFs up-regulated the expression of adhesion molecule. Based on these findings, intrauterine exosomes should be considered as an essential constituent for successful implantation.

Continuous model of conceptus implantation to the maternal endometrium

As placental morphology as well as trophoblast characteristics exhibit wide diversity across mammalian species, underling molecules were also thought to vary greatly. In the majority of cases, however, regardless of the mode of implantation, physiological and biochemical processes in conceptus implantation to the maternal endometrium including the kinds of gene expression and their products are now considered to share many similarities. In fact, recent progress has identified that in addition to the hormones, cytokines, proteases and cell adhesion molecules classically characterized, molecules related to lymphocyte homing and epithelial-mesenchymal transition (EMT) are all required for the progression of conceptus implantation to placentation. In this review, therefore, the newest findings are all incorporated into the molecular and cellular events related to conceptus implantation to the maternal endometrium; primarily from non-invasive bovine placentation and also from invasive human implantation.

Effect of Endometrial Injury on Secretion of Endometrial Cytokines and IVF Outcomes in Women with Unexplained Subfertility

In order to determine the effect of endometrial injury (EI) on in vitro fertilization (IVF) outcomes in women with unexplained subfertility and explore the relationship between EI and endometrial inflammatory cytokines, 66 women with unexplained subfertility undergoing IVF treatment were recruited. 38 patients in the EI group underwent EI in the mid-luteal phase of the cycle and 28 patients in the non-EI (NEI) group. According to the pregnancy outcome, the NEI and EI groups were divided into NEI-nonpregnant (NEI-NP), NEI-pregnant (NEI-P), EI-NP, and EI-P. All patients underwent aspiration of endometrial secretions immediately before embryo transfer. The concentrations of ten mediators were measured using Milliplex Magnetic Bead assay. The clinical pregnancy was significantly higher in the EI than in the NEI group. The concentrations of interleukin- (IL-) 6, IL-8, IL-12 (p70), IL-13, interferon- (IFN-) γ, monocyte chemotactic protein- (MCP-) 1, and vascular endothelial growth factor (VEGF) were significantly higher in the EI than the NEI group. The expression of IFN-γ and VEGF in the EI-P was significantly increased compared to the EI-NP group. These findings suggest that, in women with unexplained subfertility, endometrial injury might be a potential method to improve clinical pregnancy rates by promoting the expression of IFN-γ and VEGF.

Conceptus implantation and placentation: molecules related to epithelial-mesenchymal transition, lymphocyte homing, endogenous retroviruses, and exosomes

Processes of conceptus implantation and placentation, unique to mammalian reproduction, have been extensively studied. It was once thought that processes of these events varied greatly, notably between invasive and noninvasive modes of implantation and/or placentation. Regardless of the mode of implantation, however, physiological and biochemical processes in conceptus implantation to the maternal endometrium including the kinds of gene expression and their products are now considered not to differ so much. Recent progress has identified that in addition to the hormones, cytokines, proteases and cell adhesion molecules classically characterized, epithelial-mesenchymal transition, molecules related to lymphocyte homing, the expression of endogenous retroviruses and possibly exosomes are all required for the progression of conceptus implantation to placentation. In this review, therefore, new findings related to these events are integrated into the context of conceptus implantation to the maternal endometrium.

Association of tissue inhibitor of metalloproteinase gene polymorphisms and unexplained recurrent spontaneous abortions in Han Chinese couples

OBJECTIVE

To investigate the association of tissue inhibitor of metalloproteinase (TIMP) gene polymorphisms with unexplained recurrent spontaneous abortions (URSA) in a well-defined group of Han Chinese couples.

STUDY DESIGN

This is a case-control association study. Genomic DNA was extracted from peripheral blood samples from 84 couples with histories of three or more pregnancy losses and 69 age-matched healthy couples with at least one live birth and no histories of pregnancy loss. Polymerase chain reactions (PCRs) and sequencing with the fluorescent dye dideoxy-termination method were used to detect the rs4898 in TIMP-1, rs2277698 in TIMP-2, rs2234921 and rs5749511 in TIMP-3 and rs17035945 in TIMP-4 genotypes and allele frequencies.

RESULTS

Neither the allele frequencies nor any of the genetic model of the five TIMP gene SNPs (i.e., TIMP-1-rs4898, TIMP-2-rs2277698, TIMP-3-rs5749511 and rs2234921, and TIMP-4-rs7035945) were significantly differences between the URSA couples and the control group.

CONCLUSIONS

No evidence was found for any associations between the TIMP-1,-2,-3, or -4 genes SNPs with URSA in this Han Chinese Han.

Involvement of VCAM1 in the bovine conceptus adhesion to the uterine endometrium

Following bidirectional communication, the conceptus and the uterine epithelium must establish a proper cell-cell interaction, resulting in the progression of implantation processes. To clarify the mechanism of conceptus attachment to the uterine endometrium, we studied whether vascular cell adhesion molecule (VCAM1) was expressed in bovine conceptuses or endometrium during the peri-attachment period. Uterine VCAM1 expression was minimal in day 17 (day 0=day of estrus) cyclic and pregnant animals, but increased between days 20 and 22 of pregnancy. In the intercaruncular regions, VCAM1 protein was localized to the luminal and glandular epithelia, whereas in the caruncular regions, VCAM1 protein was detected in the stroma and endothelia of the uterine endometrium. In cultured endometrial epithelial cells (EECs), VCAM1 expression was up-regulated when treated with uterine flushings or growth factor and further increased when EECs were cocultured with bovine trophoblast CT1 cells. VCAM1 expression in CT1 cells was also up-regulated with the use of uterine flushings, and further increased when these cells were cocultured with EECs. Expression of VCAM1 receptor, integrin α 4 (ITGA4) mRNA, increased significantly in day 22 conceptuses. In day 22 pregnant uteri, VCAM1 protein was found in both EECs and conceptuses, but ITGA4 was localized only to trophoblasts. These observations indicate that cell-cell interactions between conceptuses and uterine epithelial cells are required for sufficient VCAM1 and ITGA4 expression in the bovine species and suggest that uterine VCAM1 and conceptus ITGA4 play a role in the establishment of conceptus adhesion to the uterine endometrium.

Endometrial scratching to improve pregnancy rate in couples with unexplained subfertility: a randomized controlled trial

AIM

The aim of this study was to examine the effect of endometrial scratching in women with unexplained infertility.

MATERIAL AND METHODS

A randomized controlled trial was conducted in Mansoura University Teaching Hospital and a private practice setting. A total of 105 couples with unexplained infertility were randomly allocated into two groups: group A comprised 54 women who underwent endometrial scratching in the luteal phase of a spontaneous menstrual cycle; and group B included 51 women who underwent a placebo procedure. The main outcome measured was cumulative clinical pregnancy rate after 6 months and miscarriage rate.

RESULTS

Clinical pregnancy rate was significantly higher in the women experiencing endometrial biopsy than in the control group (25.9% and 9.8%, respectively, P = 0.04). There was no significant difference in miscarriage rate between pregnant women in the endometrial injury group and pregnant women in the control group (12.5% and 16.5%, respectively, P = 0.79).

CONCLUSIONS

Endometrial scratching may improve clinical pregnancy rates in couples with unexplained infertility. Adequately powered studies are mandated to confirm or refute the findings.

NLF2 gene expression in the endometrium of patients with implantation failure after IVF treatment

The aim of this study was to analyze the expression of microfibril-associated protein 2 (MFAP2), microfibril-associated protein 5 (MFAP5) and nuclear localized factor 2 (NLF2) genes in patients with repeated IVF failure and compare with fertile population. Total RNA was isolated from 38 patients (repeated implantation failure, group 1, n=22; fertile patients, group 2, n=16). mRNA expression levels were measured quantitatively using real-time polymerase chain reaction. Our results showed that mRNA expression of NLF2 significantly decreased in the infertility group as compared to control group (P=0.023). In addition a marked decrease was observed in the expression of MFAP2 in women with repeated implantation failure. In conclusion, NLF2 gene expression levels and differences in MFAP2 and MFAP5 gene expressions (albeit being insignificant) between infertile group and control group draw attention to a genetic basis under implantation failure.

Association between testicular Aryl hydrocarbon Receptor levels and idiopathic male infertility: a case-control study in Iran

Increased urinary concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) and their metabolites are associated with increased risk of unexplained infertility in males. The toxicity of PAHs and dioxins are exclusively mediated through Aryl hydrocarbon Receptor (AhR). AhR overexpression contributes to the loss of normal ovarian function in polluted environments but its expression level in unexplained male infertility has remained unclear. This study aimed to compare the differential testicular levels of AhR and its interactions with other fundamental genes (ER, AR, PgR and MMP9) in a case control study. To conduct the immunohistochemical studies, 29 unexplained infertile and 10 fertile males were selected retrospectively from Jahad pathology center of Tehran from 2007 to 2009. Differential expression of AhR in Leydig, Sertoli, spermatogonia, spermatocyte, spermatid, and spermatozoa cells was determined and AhR association with other genes was compared between cases and controls. Higher levels of AhR in Leydig cells (p=0.024), Sertoli cells (p=0.041) and spermatid cells (p=0.028) of infertile men have emphasized the susceptibility of these cells to environmental-induced impaired testicular functions. Moreover 85% of infertile cases showed coexpression of AhR and MMP9 in their Leydig cells (p=0.02). Inactivation of ER, PgR and AR in AhR positive testicular cells suggests the antagonistic interactions between AhR ligands and sex steroid hormones receptors. It seems that unexplained male infertility could be originated from environmental AhR ligands which overexpress the AhR in Leydig cells, downregulate the expression of sex steroid receptors and upregulate the MMP9 in Leydig cells as the main testicular target cell of AhR ligands.

Association of controlled ovarian hyperstimulation treatment with down-regulation of key regulators involved in embryonic implantation in mice

The debate exists whether or not gonadotropin-releasing hormone (GnRH) analogs used in controlled ovarian hyperstimulation (COH) impair endometrial receptivity. Homeobox A11 (Hoxa11), Meis homeobox 1 (Meis1), cadherin 1 (Cdh1), and catenin beta 1 (Ctnnb1) are well known to be involved in successful implantation. In this study, the endometrial expression of Hoxa11, Meis1, Cdh1, and Ctnnb1 during the peri-implantation period was investigated in an in vitro fertilization (IVF) mouse model by real-time RT-PCR and Western blot to evaluate the relationship between Hoxa11, Meis1, Cdh1, and Ctnnb1 expression and the impact of the COH on endometrial receptivity. The mimic COH protocols included GnRH agonist plus human menopausal gonadotropin (HMG) (GnRH agonist group), GnRH antagonist plus HMG (GnRH antagonist group), and HMG alone (HMG group). The expression levels of Hoxa11, Meis1, Cdh1, and Ctnnb1 mRNA and protein were decreased in all of the COH groups. The expression levels of Hoxa11 and Ctnnb1 were the lowest in the GnRH agonist group, and those of Meis1 and Cdh1 were lower in the GnRH analog groups than the HMG group. There were positive correlations between the expression of Hoxa11 and Ctnnb1, as well as the expression of Meis1 and Cdh1 among all the groups. In conclusion, the COH protocols, particularly with GnRH analogs, suppressed Hoxa11, Meis1, Ctnnb1 and Cdh1 expression, in mouse endometrium during the peri-implantation period. Our data reveal a novel molecular mechanism by which the COH protocols might impair endometrial receptivity.