Embryo Implantation Research Articles

Autophagy and Female Fertility: Mechanisms, Clinical Implications, and Emerging Therapies.

Autophagy, an evolutionarily conserved cellular mechanism essential for maintaining internal stability, plays a crucial function in female reproductive ability. In this review, we discuss the complex interplay between autophagy and several facets of female reproductive health, encompassing pregnancy, ovarian functions, gynecologic malignancies, endometriosis, and infertility. Existing research emphasizes the crucial significance of autophagy in embryo implantation, specifically in the endometrium, highlighting its necessity in ensuring proper fetal development. Although some knowledge has been gained, there is still a lack of research on the specific molecular impacts of autophagy on the quality of oocytes, the growth of follicles, and general reproductive health. Autophagy plays a role in the maturation, quality, and development of oocytes. It is also involved in reproductive aging, contributing to reductions in reproductive function that occur with age. This review explores the physiological functions of autophagy in the female reproductive system, its participation in reproductive toxicity, and its important connections with the endometrium and embryo. In addition, this study investigates the possibility of emerging treatment approaches that aim to modify autophagy, using both natural substances and synthetic molecules, to improve female fertility and reproductive outcomes. Additionally, this review intends to inspire future exploration into the intricate role of autophagy in female reproductive health by reviewing recent studies and pinpointing areas where current knowledge is lacking. Subsequent investigations should prioritize the conversion of these discoveries into practical uses in the medical field, which could potentially result in groundbreaking therapies for infertility and other difficulties related to reproduction. Therefore, gaining a comprehensive understanding of the many effects of autophagy on female fertility would not only further the field of reproductive biology but also open new possibilities for diagnostic and treatment methods.

The histone methyltransferase KMT2D is essential for embryo implantation via regulating precise differentiation of endometrial cells

Embryo implantation failures are a major challenge in reproductive medicine, but the underlying mechanism remains poorly understood. Successful implantation requires dynamic remodeling of the endometrium through integrated proliferation and differentiation of endometrial cells including luminal epithelial, glandular epithelial, and stromal cells. Conversely, their disruption causes infertility. Spatiotemporal control of transcription is required for these processes; however, the underlying epigenetic regulation is largely unknown. In this study, we examined expression data from the human endometrium during implantation and discovered that expression of the histone lysine methyltransferase KMT2D was significantly suppressed in patients with recurrent implantation failure. Further study revealed that uterine deletion of Kmt2d in mice caused infertility due to implantation failure. Morphological analysis discovered a reduction in the number of uterine glands and aberrant differentiation of the luminal and glandular epithelium into stratified phenotypes in Kmt2d knockout uteri. Administration of leukemia inhibitory factor protein, which is expressed in uterine glands and is essential for implantation, did not rescue implantation failure in Kmt2d knockout mice, suggesting that infertility was not solely due to uterine gland dysfunction. RNA sequencing analysis revealed that Kmt2d knockout uteri displayed suppressed expression of genes involved in ion homeostasis, which may affect the uterine luminal morphology. Our study suggests that KMT2D plays an essential role in facilitating successful embryo implantation by regulating the coordinated differentiation of endometrial cells, providing valuable insights into unexplained implantation failures in women.

Monoamine oxidases activity maintains endometrial monoamine homeostasis and participates in embryo implantation and development

BackgroundMonoamine oxidases (MAOs) is an enzyme that catalyzes the deamination of monoamines. The current research on this enzyme is focused on its role in neuropsychiatric, neurodevelopmental, and neurodegenerative diseases. Indeed, MAOs with two isoforms, namely, A and B, are located on the outer mitochondrial membrane and are widely distributed in the central nervous system and peripheral tissues. Several reports have described periodic changes in the levels of this enzyme in the human endometrial tissue.ResultsThe novel role of MAOs in endometrial receptivity establishment and embryonic development by maintaining monoamine homeostasis was investigated in this study. MAOs activity was observed to be enhanced during the first trimester in both humans and mice under normal conditions. However, under pathological conditions, MAOs activity was reduced and was linked to early pregnancy failure. During the secretory phase, the endometrial stromal cells differentiated into decidual cells with a stronger metabolism of monoamines by MAOs. Excessive monoamine levels cause monoamine imbalance in decidual cells, which results in the activation of the AKT signal, decreased FOXO1 expression, and decidual dysfunction.ConclusionsThe findings suggest that endometrial receptivity depends on the maintenance of monoamine homeostasis via MAOs activity and that this enzyme participates in embryo implantation and development.

Transcriptome comparisons of trophoblasts from regenerative cell models with peri-implantation human embryos.

Mechanisms controlling trophoblast proliferation and differentiation during embryo implantation are poorly understood. Human trophoblast stem cells (TSC) and BMP4/A83-01/PD173074-treated pluripotent stem cell-derived trophoblast cells (BAP) are two widely employed, contemporary models to study trophoblast development and function, but how faithfully they mimic early trophoblast cells has not been fully examined. We evaluated the transcriptomes of trophoblast cells from BAP and TSC and directly compared them with those from peri-implantation human embryos during extended embryo culture (EEC) between embryonic day 8 to 12. The BAP and TSC grouped closely with trophoblast cells from EEC within each trophoblast sublineage following dimensional analysis and unsupervised hierarchical clustering. However, subtle differences in transcriptional programs existed within each trophoblast sublineage. We also validated the presence of six genes in peri-implantation human embryos by immunolocalization. Our analysis reveals that both BAP and TSC models have features of peri-implantation trophoblasts, while maintaining minor transcriptomic differences, and thus serve as valuable tools for studying implantation in lieu of human embryos.

The activation of cGAS-STING pathway causes abnormal uterine receptivity in aged mice.

Maternal age is one of the most important factors affecting the success of maternal pregnancy. Uterine aging is the leading cause of pregnancy failure in older women. However, how uterine aging affects uterine receptivity and decidualization is unclear. In this study, naturally aged one-year-old female mice were used to investigate effects of maternal age on embryo implantation during early pregnancy. In our study, we found abnormal uterine receptivity in aged mice. Aged mouse uterus indicates a decrease in nuclear LAMIN A, and an increase in PRELAMIN A and PROGERIN. In aged mouse uterus, double-stranded DNA (dsDNA) in cytoplasmic fraction is significantly increased. PROGERIN overexpression in mouse uterine epithelial cells and epithelial organoids leads to nuclear DNA leakage and impaired uterine receptivity. DNase I, DNase II, and TREX1 are obviously reduced in aged mouse uterus. Treatments with foreign DNA or STING agonist significantly downregulate uterine receptivity markers and activate cGAS-STING pathway. Uterine estrogen (E2) concentration is significantly increased in aged mice. After ovariectomized mice are treated with a high level of E2, there are significant increase of PROGERIN and cytoplasmic DNA, and activation of cGAS-STING pathway. CD14 is significantly increased in aged uterus. Intrauterine CD14 injection inhibits embryo implantation. Invitro CD14 treatment of cultured epithelial cells or epithelial organoids decreases uterine receptivity. Uterine abnormality in aged mouse can be partially rescued by STING inhibitor. In conclusion, uterine PROGERIN increase in aged mouse uterus results in cytoplasmic DNA accumulation and cGAS-STING pathway activation. CD14 secretion in aged uterus impairs uterine receptivity.

Effects of 'dedo de moça' pepper extract administration on wistar rat pregnancy and fetal development

Introduction: The dedo de moça pepper is spicy due to capsaicin, which activates receptors in sensory neurons, generating a burning sensation. Studies suggest that capsaicin-sensitive neurons, by releasing neuropeptides, may affect uterine contraction. Objective: To evaluate the effect of chronic administration of capsaicin extract (Cps) during pregnancy in Wistar rats and their fetuses. Methodology: Pregnant female Wistar rats were divided into 4 groups (n = 5/group): Group I – Negative Control; Group II – Positive Control; Group III – Cps 1 – 0.25 mL; Group IV – Cps 2 – 0.5 mL. Exposure was initiated after embryo implantation (3rd day of pregnancy) until full term (20th day of pregnancy), with gavage performed three times per week. Results: On the 20th day, pregnant rats were euthanized, and outcomes evaluated included weight gain, placental morphology, reproductive capacity, and embryonic/fetal development. Ingestion of capsaicin extract resulted in negative impacts on fetal intrauterine growth parameters and placental alterations, with deposition of atypical hyaline material for gestational age and changes in vascular structures. Conclusion: The results indicate that capsaicin extract interfered with placental exchange, leading to intrauterine growth restriction of the fetuses.

Effects of Zishen Yutai pills combined with metformin on women with polycystic ovary syndrome undergoing in vitro fertilization.

In this study, we analyzed the clinical efficacy of Zishen Yutai pills (ZSYTP) combined with metformin hydrochloride on infertile women diagnosed with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization and embryo transfer (IVF-ET). Patients were assigned into 3 groups: the ZSYTP group (n = 50), the metformin group (n = 50), and the combination group (ZSYTP combined with metformin hydrochloride, n = 50), based on their respective and the indicated treatments before undergoing IVF-ET. Then, their glucose metabolism indices, sex hormone indices, traditional Chinese medicine (TCM) syndrome scores, and outcomes of IVF-ET were compared. Baseline characteristics were not significantly different between the 2 groups. After treatment, various parameters such as body mass index (BMI), fasting plasma glucose (FPG), fasting insulin (FIN), homeostatic model assessment of insulin resistance (HOMA-IR), luteinizing hormone (LH), estradiol (E2), follicle-stimulating hormone (FSH), testosterone (T) levels, and TCM syndrome scores were found to be reduced compared to pretreatment levels in both groups. Moreover, the improvement observed in the treatment group exceeded that of the control group. Specifically, the observation group displayed significantly lower gonadotropin (Gn) dosage and duration, as well as a reduced abortion rate compared to the control group. Furthermore, the observation group had higher numbers of obtained eggs, high-quality embryos, eggs obtained through IVF-ET, average transferred embryos, clinical pregnancy rate, and embryo implantation rate compared to the control group. Pretreatment with ZSYTP combined with metformin before IVF-ET in PCOS patients improves the outcome of IVF-ET.

ST6GALNAC1-mediated sialylation in uterine endometrial epithelium facilitates the epithelium-embryo attachment

IntroductionEmbryo implantation requires synergistic interaction between the embryo and the receptive endometrium. Glycoproteins and glycan-binding proteins are involved in endometrium-embryo attachment. Sialyl Tn (sTn), a truncated O-glycan, is catalyzed by ST6 N-Acetylgalactosaminide Alpha-2,6-Sialyltransferase 1 (ST6GALNAC1) and can be detected by specific Sialic-acid-binding immunoglobulin-like lectins (Siglecs). Whether the sTn-Siglecs axis supports embryo implantation remains unknown. ObjectivesThis paper aims to study the role of ST6GALNAC1/sTn-Siglecs axis in embryo implantation. MethodsST6GALNAC1 and sTn in human endometrium were analyzed by immunohistochemistry. An in vitro implantation model was conducted to evaluate the effects of ST6GALNAC1/sTn on the receptivity of human endometrial AN3CA cells to JAR spheroids. Immunoprecipitation combined with mass spectrometry analysis was carried out to identify the key proteins modified by sTn in endometrial cells. Siglec-6 in human embryos was analyzed by published single-cell RNA sequencing (scRNA-seq) datasets. Protein interaction assay was applied to verify the bond between the Siglec-6 with sTn-modified CD44. St6galnac1 siRNAs and anti-sTn antibodies were injected into the uterine horn of the mouse at the pre-implantation stage to evaluate the role of endometrial St6galnac1/sTn in embryo implantation. Siglec-G in murine embryos was analyzed by immunofluorescence staining. The function of Siglec-G is evidenced by uterine horn injection and protein interaction assay. ResultsBoth human and murine endometrium at the receptive stage exhibit higher ST6GALNAC1 and sTn levels compared to the non-receptive stage. Overexpression of ST6GALNAC1 significantly enhanced the receptivity of AN3CA cells to JAR spheroids. Inhibition of endometrial ST6GALNAC1/sTn substantially impaired embryo implantation in vivo. CD44 was identified as a carrier for sTn in the endometrial cells of both species. Siglec-6 and Siglec-G, expressed in the embryonic trophectoderm, were found to promote embryo attachment, which may be achieved through binding with sTn-modified CD44. ConclusionST6GALNAC1-regulated sTn in the endometrium aids in embryo attachment through interaction with trophoblastic Siglecs.

The role of microRNAs in the regulation of critical genes and signalling pathways that determine endometrial receptivity.

Endometrial receptivity is the ability of the endometrium to accept embryos. Thus, endometrial receptivity dysfunction is an important factor leading to embryo implantation failure. A good endometrial receptivity provides a suitable environment for embryo implantation, improving the embryo implantation rate. The "implantation window" stage, or the receptive stage of the endometrium, is regulated by various hormones, genes, proteins and cytokines, among which microRNAs (miRNAs) and their target genes have a regulatory effect on endometrial receptivity. This review outlines the relationship between endometrial receptivity and pregnancy, the mRNAs and related signalling pathways that regulate endometrial receptivity, and the regulatory role of miRNA in endometrial receptivity, providing a deeper understanding of the regulatory mechanisms of miRNA on endometrial receptivity in humans and animals and reference for the endometrial receptivity-related research.

Preovulation body mass index and pregnancy after first frozen embryo transfer in patients with polycystic ovary syndrome and insulin resistance

ObjectiveTo examine the association between preovulation body mass index and pregnancy outcomes after frozen embryo transfer in patients with polycystic ovary syndrome with insulin resistance. DesignThis was a single-center, retrospective cohort study. SubjectsWomen with infertility, diagnosed with polycystic ovary syndrome and insulin resistance, and treated at the Reproductive Medicine Center, Second People’s Hospital of Nanning, China, between January 2020 and August 2023, were included. ExposurePatients were divided into four groups according to their body mass index (BMI): slim (<18.5 kg/m2), normal (18.5≤ BMI <24 kg/m2), overweight (24≤ BMI <28 kg/m2), or obese (≥28 kg/m2). Main Outcome MeasuresThe main pregnancy outcomes included rates of embryo implantation, biochemical pregnancy, clinical pregnancy, and ongoing pregnancy. ResultsIn total, 282 eligible patients were included. A linear association was observed between the BMI and clinical pregnancy outcomes of the first frozen embryo transfer (P for nonlinearity>0.05). After accounting for all potential variables, each 1 kg/m2 increase in BMI was linked to a 2% decrease in the embryo implantation rate (P<0.05), 11% decrease in the frequency of biochemical pregnancy (P<0.05), and 9% decrease in the both clinical (P<0.05) and ongoing pregnancy rates. ConclusionIn patients with polycystic ovary syndrome and insulin resistance, a higher BMI was associated with lower rates of embryo implantation, biochemical pregnancy, clinical pregnancy, and ongoing pregnancy.

IL-2 Complexed With Anti–IL-2 Antibody Expands the Maternal T-Regulatory Cell Pool and Alleviates Fetal Loss in Abortion-Prone Mice

Regulatory T (Treg) cells are essential for immune tolerance of embryo implantation and insufficient Treg cells are implicated in early pregnancy loss. An abortion-prone mouse model was utilized to evaluate the utility of IL-2 complexed with JES6-1 anti-IL-2 antibody (IL-2/JES6-1) to boost uterine Treg cells and improve reproductive success. IL-2/JES6-1 but not IL-2/IgG control administered in the peri-conception phase to CBA/J females mated with DBA/2 males elicited a >2-fold increase in the proportion of CD4+ T cells expressing FOXP3, and an increase in the ratio of FOXP3+ Treg cells to FOXP3- T conventional cells, in the uterus and its draining lymph nodes at embryo implantation that was sustained into mid-gestation. An attenuated phenotype was evident in both thymic-derived and peripheral Treg cells with elevated CTLA4, CD25, and FOXP3 indicating improved suppressive function, as well as increased proliferative marker Ki67. IL-2/JES6-1 treatment reduced fetal loss from 31% to 10%, but this was accompanied by a 6% reduction in late gestation fetal weight, despite comparable placental size and architecture. Similar effects of IL-2/JES6-1 on Treg cells and fetal growth were seen in CBA/J females with healthy pregnancies sired by BALB/c males. These findings show that expanding the uterine Treg cell pool through targeting IL-2 signaling is a strategy worthy of further investigation for mitigating immune-mediated fetal loss.

Fetal growth restriction and placental defects in obese mice are associated with impaired decidualisation: the role of increased leptin signalling modulators SOCS3 and PTPN2

Decidualisation of the endometrium is a key event in early pregnancy, which enables embryo implantation. Importantly, the molecular processes impairing decidualisation in obese mothers are yet to be characterised. We hypothesise that impaired decidualisation in obese mice is mediated by the upregulation of leptin modulators, the suppressor of cytokine signalling 3 (SOCS3) and the protein tyrosine phosphatase non-receptor type 2 (PTPN2), together with the disruption of progesterone (P4)-signal transducer and activator of transcription (STAT3) signalling. After feeding mice with chow diet (CD) or high-fat diet (HFD) for 16 weeks, we confirmed the downregulation of P4 and oestradiol (E2) steroid receptors in decidua from embryonic day (E) 6.5 and decreased proliferation of stromal cells from HFD. In vitro decidualised mouse endometrial stromal cells (MESCs) and E6.5 deciduas from the HFD showed decreased expression of decidualisation markers, followed by the upregulation of SOCS3 and PTPN2 and decreased phosphorylation of STAT3. In vivo and in vitro leptin treatment of mice and MESCs mimicked the results observed in the obese model. The downregulation of Socs3 and Ptpn2 after siRNA transfection of MESCs from HFD mice restored the expression level of decidualisation markers. Finally, DIO mice placentas from E18.5 showed decreased labyrinth development and vascularisation and fetal growth restricted embryos. The present study revealed major defects in decidualisation in obese mice, characterised by altered uterine response to E2 and P4 steroid signalling. Importantly, altered hormonal response was associated with increased expression of leptin signalling modulators SOCS3 and PTPN2. Elevated levels of SOCS3 and PTPN2 were shown to molecularly affect decidualisation in obese mice, potentially disrupting the STAT3-PR regulatory molecular hub.

Acupuncture combined with gonadotropin-releasing hormone agonists improves endometrial receptivity and pregnancy outcome in patients with recurrent implantation failure of in vitro fertilization-embryo transfer.

Gonadotropin-releasing hormone agonists (GnRHa), combined with other auxiliary treatments, can improve pregnancy outcomes in in vitro fertilization-embryo transfer (IVF-ET). This research investigated the effect of acupuncture combined with GnRHa in patients with recurrent implantation failure (RIF) of IVF-ET. A total of 164 patients who intended to undergo frozen-thawed embryo transfer after RIF of IVF-ET were selected for experiments and then divided into the control (received conventional hormone replacement therapy (HRT) for endometrial preparation) and study groups (received a combination of acupuncture, GnRHa, and HRT for endometrial preparation) (n = 82). Endometrial thickness (EMT), endometrial morphological classification, submucosal uterine blood flow classification, clinical pregnancy rate, embryo implantation rate, and early abortion rate for each transfer cycle were compared between the two groups. EMT of the study group was higher than that of the control group 1 day before transfer. There were more patients with linear endometrium (A + B type) in the study group on the day of endometrial transformation than in the control group. The number of patients with type I submucosal uterine blood flow in the study group was decreased and the number of patients with type III was increased compared with the control group on the day of endometrial transformation. The clinical pregnancy rate and embryo implantation rate of the study group were higher than those of the control group. Acupuncture combined with GnRHa improves the endometrial receptivity of patients with RIF of IVF-ET, thereby increasing clinical pregnancy rates and improving pregnancy outcomes.

Intrauterine administration of paternal and maternal peripheral blood mononuclear cells mix as solution for repeated implantation failure.

To date, implantation is the rate-limiting step for the success of in vitro fertilization (IVF) treatment. Accumulating evidence suggests that immune cells contribute to embryo implantation, and several therapeutic approaches have been proposed for the treatment of recurrent implantation failure (RIF). Endometrial immune modulation with autologous activated peripheral blood mononuclear cells (PBMCs) is one of the most widely used protocols. However, the effect of intrauterine insemination of mixed paternal and maternal-activated PBMCs has not yet been attempted and studied. The aim of our study is to test the effect of the addition of paternal lymphocytes on the implantation rate in RIF patients. Mononuclear cells were isolated from the peripheral blood of 98 RIF patients and cultured for 72h before insemination into the endometrial cavity 48h before embryo transfer. Our patients were divided into 4 groups according to the type and number of PBMCs inseminations. Our study shows that activated PBMCs promoted clinical pregnancy rates (CPR) in all groups. Moreover, we found that the groups injected with more than 2 million cells showed a better clinical outcome and, more interestingly, patients inseminated with both paternal and maternal activated PBMCs showed the highest CPR, reaching 47.2%, in addition to the highest implantation rate 31. 2% and the live birth rate 41.39%. Our work demonstrates the importance of administering a large number of activated PBMCs with the addition of paternal activated PBMCs to immunomodulate the endometrium for the success of in vitro fertilization in RIF patients.

Cervical Cancer Evades the Host Immune System through the Inhibition of Type I Interferon and CXCL9 by LIF.

Cervical cancer is a viral-associated tumor caused by the infection with the human papilloma virus. Cervical cancer is an immunogenic cancer that expresses viral antigens. Despite being immunogenic, cervical cancer does not fully respond to immune checkpoint inhibitors (ICI). LIF is a crucial cytokine in embryo implantation, involved in maternal tolerance that acts as an immunomodulatory factor in cancer. LIF is expressed in cervical cancer and high levels of LIF is associated with poor prognosis in cervical cancer. We evaluated the impact of LIF on the immune response to ICI using primary plasmocytoid dendritic cells (pDC) and macrophage cultures, syngeneic animals and patient-derived models that recapitulate the human tumor microenvironment. We found that the viral proteins E6 and E7 induce the expression of LIF via the NFκB pathway. The secreted LIF can then repress type I interferon expressed in pDCs and CXCL9 expressed in tumor-associated macrophages. Blockade of LIF promotes the induction of type I interferon and CXCL9 inducing the tumor infiltration of CD8 T cells. This results in the sensitization of the tumor to ICI. Importantly, we observed that patients with cervical cancer expressing high levels of LIF tend to be resistant to ICI. Our data show that the HPV virus induces the expression of LIF to provide a selective advantage to the tumor cell by generating local immunosuppression via the repression of type I interferon and CXCL9. Combinatory treatment with blocking antibodies against LIF and ICI could be effective against cervical cancer expressing high levels of LIF.

Impact of Luteinizing Hormone on IVF/ICSI Assisted Reproduction on the Initiation Day of Gonadotropin-releasing Hormone Antagonist Protocol.

The aim of the study was to explore the optimal timing of gonadotropin initiation and the reasonable interval of luteinizing hormone (LH) levels in the gonadotropin-releasing hormone antagonist (GnRH-A) protocol. A retrospective cohort study was conducted to analyze the data concerning the oocyte retrieval cycles from 1,361 cases with the GnRH-A protocol implemented. The ovarian responses (including AMH, AFC) in these patients were divided into the poor ovarian response group (an antral follicle count [AFC] ≤ 6, n = 394), the normal ovarian response group (an AFC > 6 and < 15, n = 570), and the high ovarian response group (an AFC ≥ 15, n = 397), according to the AFC. The patients were sub-grouped according to LH levels on the protocol initiation day, and the clinical outcomes (including dose of Gn initiation, Gn administration days, GnRH-ant administration days, P levels on the HCG day, E2 levels on the HCG day, LH levels on the HCG day, number of embryos transferred, total fertilization rate, embryo implantation rate(%), proportion of 2PN, proportion of good-quality embryos, endometrial thickness on the hCG injection day(mm), moderate to severe OHSS, AFC on the initiation day, proportion of type A endometrium on the hCG injection day, clinical pregnancy rate, biochemical pregnancy rate, early abortion rate, ectopic pregnancy rate) were compared. On the GnRH-A protocol initiation day, among all patients with different ovarian responses, the body mass index (BMI) in those with an LH ≥ 5 IU/L was lower. The differences in pregnancy outcomes between the LH < 5 IU/L group and the LH ≥ 5 IU/L group were not statistically significant across the different ovarian response groups, but the LH < 5 IU/L group had a higher proportion of good-quality embryos (80.3±24.9 vs. 74.8±26.9, P =0.035) than the LH≥5IU/Lgroup in those with poor ovarian response. The total fertilization rate (82.2±18.1 vs 85.4±15.1, P =0.021) and proportion of two pronuclei (2PN) (69.0±20.9 vs 72.7±19.9, P =0.035) were higher in the LH ≥ 5 IU/L group than the LH<5 IU/L group for those with normal ovarian responses. The embryo implantation rate (41.4±41.3 vs 52.6±43.4, P =0.012) was higher in the LH ≥ 5 IU/L group than in the LH<5 IU/L group in those with high ovarian response. The results of the multivariate logistic analysis showed that the age of the female partner, number of embryos transferred, proportion of good-quality embryos, endometrial thickness on the hCG injection day, and moderate- to-severe ovarian hyperstimulation syndrome (OHSS) were independent factors correlated with the outcome of live births (P < 0.05). The LH levels on the gonadotropins (Gn) initiation day in the GnRH-A protocol will not affect pregnancy outcomes.

The Role of Immunological Factors in Recurrent Miscarriage and Advances in Immunotherapy

Recurrent miscarriage is a complex reproductive health problem when a woman suffers spontaneous miscarriage during two or more consecutive pregnancies. Recurrent miscarriage is a distressing condition in which immune factors play an important role. The immune system has an impact on the processes of embryo implantation, growth and development, and immune abnormalities may lead to rejection of the foetus or difficulties in implantation, thus triggering recurrent miscarriage. Therefore, the role of immune factors in recurrent miscarriages and advances in immunotherapy will open up more possibilities and hopefully bring new reproductive hopes and possibilities to couples who suffer from recurrent miscarriages.

The effect of endometriosis on the fertility of women

Endometriosis is defined by the presence of ectopic endometrial tissue outside the uterus, frequently located on pelvic organs such as the fallopian tubes and ovaries, and occasionally beyond the pelvic region. This condition manifests as dysmenorrhea, chronic pelvic pain, dyspareunia, and subfertility. Despite extensive research, the etiology and pathogenesis of endometriosis remain unclear, with laparoscopy being the definitive diagnostic method. The association between endometriosis and infertility has been extensively debated. Endometriosis can impair fertility by disrupting embryo implantation, altering hormone levels, and compromising oocyte quality. This literature review aims to examine the effects of endometriosis on female fertility. The review encompasses documents from clinical trials with control groups involving 196 to 22,416 reproductive-age participants (25-42 years), and case studies published over the past thirty-seven years from various regions (USA, Australia, Turkey, Africa, and Europe. Reputable databases such as BMJ, NEJM, Elsevier, AJR, Medline, and PubMed were utilized, with references compiled in the bibliography. A risk-benefit analysis indicates that up to 50% of women with endometriosis experience infertility. Consensus on treatment options remains elusive. The relationship between endometriosis and infertility is supported by studies of both fertile and infertile women, animal studies, donor sperm studies, and in vitro fertilization outcomes. Diagnostic methodologies based on endometrial changes are providing insights into potential mechanisms of infertility, especially in women with milder disease. However, clinical management of endometriosis-related infertility has not shown conclusive success beyond in vitro fertilization.

Osteopontin expression in dromedary camel's conceptuses during the peri-implantation period.

The reproductive efficiency of dromedary camels is hindered by challenges such as early embryonic mortality, which may be attributed to a lack of synchronization between conceptus signalling and uterine receptivity. Understanding the intricate biological processes involved in feto-maternal interactions during implantation is crucial to address these limitations. Osteopontin (OPN) is a protein involved in cell signalling and adhesion, playing a crucial role in embryonic implantation. Previous studies have shown the presence of OPN in the uterine endometrium of various mammalian species including dromedary camels. However, the expression pattern of OPN in dromedary conceptuses remains unexplored. Thus, the current study aimed, for the first time, to investigate the temporospatial expression of OPN in dromedary conceptuses during the peri-implantation period at Days 8, 10, and 12 of pregnancy. Twelve conceptuses were recovered non-surgically from pregnant females on Days 8, 10, 12 of pregnancy. Quantitative real-time PCR (qrt-PCR), immunohistochemistry (IHC), and immunofluorescence (IF) were employed for analysis of the expression of OPN mRNA and protein. The results revealed significant increases in both OPN mRNA and protein expression started on Day 10 and peaked at Day 12 of pregnancy. Immuno-localization confirmed the presence of OPN protein in the trophectoderm and endoderm of dromedary conceptuses. In conclusion, the expression and localization of OPN during the peri-implantation period in dromedary conceptuses imply its involvement as a crucial reproductive factor and its upregulation during this period, with a pronounced increase close to attachment time (Day 12 of pregnancy) further supports its role in embryo adhesion, implantation, and placentation.

Poised PABP–RNA hubs implement signal-dependent mRNA decay in development

Signaling pathways drive cell fate transitions largely by changing gene expression. However, the mechanisms for rapid and selective transcriptome rewiring in response to signaling cues remain elusive. Here we use deep learning to deconvolve both the sequence determinants and the trans-acting regulators that trigger extracellular signal-regulated kinase (ERK)–mitogen-activated protein kinase kinase (MEK)-induced decay of the naive pluripotency mRNAs. Timing of decay is coupled to embryo implantation through ERK–MEK phosphorylation of LIN28A, which repositions pLIN28A to the highly A+U-rich 3′ untranslated region (3′UTR) termini of naive pluripotency mRNAs. Interestingly, these A+U-rich 3′UTR termini serve as poly(A)-binding protein (PABP)-binding hubs, poised for signal-induced convergence with LIN28A. The multivalency of AUU motifs determines the efficacy of pLIN28A–PABP convergence, which enhances PABP 3′UTR binding, decreases the protection of poly(A) tails and activates mRNA decay to enable progression toward primed pluripotency. Thus, the signal-induced convergence of LIN28A with PABP–RNA hubs drives the rapid selection of naive mRNAs for decay, enabling the transcriptome remodeling that ensures swift developmental progression.