Molecular human reproduction最新文献

Activin A, encoded by the Inhba gene, is a versatile protein crucial for numerous biological processes, and its dysregulation is implicated in various human disorders. However, the perinatal lethality of Inhba knockout mice restricts the delineation of the full extent of this protein's function in the adult organism, particularly in reproduction. Here, we report the identification and characterization of a previously unrecognized Inhba  LoxP/LoxP mouse line that exhibits a seven-fold reduction in activin A levels, establishing a novel hypomorphic Inhba model. Unlike the activin A knockout mice, the obtained Inhba  LoxP/LoxP individuals survive to adulthood but exhibit impaired growth, as well as defects in hair and eye development. Notably, hypomorphic females display disrupted estrous cycles, elevated luteinizing hormone levels, and severe congenital malformations of the urogenital tract, which markedly compromise their fertility. These abnormalities arise from defective postnatal remodeling of the urogenital sinus, which normally regresses after birth to establish separate vaginal and urethral structures. Persistent urogenital sinus in adult hypomorphic females narrows the vaginal lumen, causes abnormal urethral insertion into the vaginal canal, and likely predisposes to pelvic organ prolapse, collectively preventing successful copulation. This unique mouse model thus uncovers a previously unrecognized, dosage-sensitive requirement for activin A in female reproductive development and anatomy. Overall, our findings highlight Inhba as a critical regulator of urogenital tract remodeling and identify this gene as a potential genetic component in rare human disorders such as persistent urogenital sinus and pelvic organ prolapse, paving the way for investigating the pathogenesis of these conditions.

Estrogen receptor 1 (ESR1) and progesterone receptor (PGR) are essential regulators for endometrial receptivity and embryo implantation. Their expression is dysregulated in women with endometriosis-associated infertility. However, the relationship between ESR1 and PGR within the same endometrial cellular compartments has not been clearly defined. In this study, we examined ESR1 and PGR expression and their correlation in mid-secretory phase eutopic endometrium from fertile women without endometriosis (n = 9) and infertile women with endometriosis (n = 11) using immunohistochemistry and multiplex immunofluorescence. ESR1 levels were significantly reduced in endometrial stromal cells from infertile women with endometriosis compared to controls, and this attenuation of ESR1 was tightly associated with reduced PGR expression. In contrast, although epithelial PGR is normally downregulated in receptive mid-secretory phase endometrium, aberrant epithelial PGR overexpression was strongly correlated with epithelial ESR1 levels in infertile women with endometriosis. Multiplex immunofluorescence and AI-assisted single-cell quantitative analysis further confirmed a significant positive correlation between ESR1 and PGR in both stromal and epithelial compartments in the endometriosis group. These findings reveal compartment-specific dysregulation of ESR1 and PGR expression and identify aberrant ESR1-PGR co-expression as a potential molecular feature of a non-receptive eutopic endometrium in endometriosis-associated infertility, underscoring the importance of disrupted steroid hormone signaling in impaired implantation.

PCOS is the most common reproductive endocrine disorder among women of reproductive age. It is characterized by excess androgens, anovulation, and polycystic ovarian morphology, and is often accompanied by obesity, insulin resistance and glucose metabolism abnormalities. Although PCOS is a complex disease with diverse and uncertain etiologies, metabolic dysfunction and adipose tissue abnormalities are critical components in its pathology. Previous studies have demonstrated that letrozole exposure combined with high-fat diet treatment in female mice produced key endocrine and metabolic features of PCOS, including elevated testosterone levels, anovulation, and adipocyte hypertrophy. Orosomucoid 2 (ORM2), an acute-phase protein predominantly secreted by hepatocytes, plays a regulatory role in metabolic balance and gut microbiota composition. This study aimed to investigate the effects of ORM2 levels on the metabolic and endocrine dysregulations associated with letrozole-induced PCOS in female mice. We established a letrozole-induced PCOS by treating mice with Let+HFD (letrozole and high-fat diet) for 5 weeks. Our findings revealed that compared to control females receiving placebo and high-fat diet treatment, females treated with Let+HFD exhibited significantly reduced hepatic Orm2 expression. Furthermore, Orm2 knockout mice subjected to Let+HFD treatment developed more severe ovarian pathology, higher testosterone levels, hepatocyte hypertrophy, and reduced Ucp1 expression in white adipose tissue compared to wild-type mice. Conversely, supplementation with recombinant ORM2 protein in females under Let+HFD treatment resulted in improved ovarian morphology, reduced hepatocyte cell size, and enhanced Ucp1 expression in white adipose tissue. Overall, this research identifies ORM2 as a promising therapeutic target for PCOS treatment.

Following fertilization in mice and humans, the first two blastomeres are not equivalent, but one produces more epiblast than the other (imbalance), therefore, they do not feature equal totipotency. Research into the causes has overlooked that the epiblast imbalance is preceded by a fertilization imbalance, since in nature, the spermatozoon fertilizes the oocyte preferentially in the animal hemisphere near the animal-vegetal midline (equator). We conceived a hypothesis that the two imbalances are linked to each other, and broke it down into testable predictions. If the two imbalances were interdependent, then changing the site of sperm entry into the oocyte should change the extent of the epiblast imbalance. Thus, we evened out the fertilization imbalance, using ICSI to fertilize mouse oocytes also in the vegetal hemisphere and the equator. Resultant embryos were split at the 2-cell stage, and the twin blastocysts originating from the sister blastomeres were analyzed. Against the similarity in mRNA levels of epiblast genes, twin blastocysts differed in epiblast function, as measured by NANOG protein expression and derivation of embryonic stem cells, and the epiblast imbalance was greater after oocyte fertilization at the equator. There is no simple way to explain the positional effect other than through differences in the molecular composition of the ooplasm, which, moreover, should also be apportioned variably at the first zygotic division. We tested these predictions by measuring the orientation of the first zygotic division regarding the ICSI site, and the composition of bisected oocytes' hemispheres using half-cell proteomics. Since we found that the hemispheres have different compositions depending on the bisection axis, and the angle of the first division is variable, we propose that the variable partition of non-homogeneous ooplasm sets the stage for the epiblast imbalance. These results revive the role of the oocyte's molecular architecture on embryogenesis in a mammalian species hitherto considered mostly regulative in development.

Maternal obesity is complicating an increasing number of pregnancies globally and is associated with a heightened risk of adverse obstetric and fetal outcomes. The placenta, which mediates maternal-fetal exchange, is postulated to be a key mediator of these outcomes. The development of the extensively branched placental vascular network, driven by spatial and temporal regulation of angiogenic cues, is critical to ensure efficient exchange capacity. In maternal obesity, the placenta exhibits lipotoxicity, inflammation, and a range of cellular stresses, which may impair angiogenic signalling and endothelial metabolism, thereby disrupting vascular development. Understanding the timing and nature of obesity-induced disruptions to placental vascular development is important to improve clinical monitoring, inform the development of targeted interventions to improve fetal outcomes, and reduce obesity-associated pregnancy complications. This review synthesises the current literature on the impact of maternal obesity on the placental vasculature, considering how changes in vascular architecture, angiogenic factors, and endothelial cell metabolism intersect to lead to dysfunction. Furthermore, we propose a conceptual framework to explain how distinct combinations of placental alterations may underlie the heightened risk of divergent fetal growth outcomes (both pathologically large and small babies) commonly observed in obese pregnancies.

The aim of this study was to develop an advanced in vitro model of human endometrium using single-cell-derived endometrial epithelial organoids, enabling the study of embryo secretome-endometrial crosstalk at the maternal-fetal interface. Single-cell-derived organoids generated from endometrial tissue of a parous 39-year-old woman recapitulated hormone-responsive decidualization, as demonstrated by expression of SPP1 and acetyl-α-tubulin. When cultured in embryo culture media, organoid viability was maintained with no cytotoxicity, but proliferation was suppressed, likely due to the lower concentrations of the required factors in organoid growth media. Organoids were stimulated with culture supernatants from morphologically good-quality embryos with known pregnancy outcomes (live birth (n = 4) vs no pregnancy (n = 4)). Transcriptomic profiling (RNA-sequencing) revealed that 32 genes were differentially expressed (DEGs) in organoids exposed to the culture supernatants from live-birth embryos versus non-pregnant outcomes: 24 upregulated and 8 downregulated. These DEGs were enriched for biological processes related to cell motility and cytoskeletal dynamics. In conclusion, soluble factors secreted by human blastocysts achieving live birth selectively modulate the endometrial epithelial transcriptome, enhancing pathways involved in cytoskeletal remodeling and immune modulation. This embryo-directed remodeling likely facilitates endometrial receptivity for successful implantation to occur. Our organoid model provides a robust platform for further investigating implantation failure.

The pregnancy-specific syndrome preeclampsia remains the syndrome of hypotheses. Still, there is not a single hypothesis explaining the etiology of the full spectrum of preeclampsia. This has direct consequences for the clinical management of the syndrome. So far, no single early biomarker has been identified to predict all women who will develop preeclampsia later in pregnancy. Similarly, no preventive treatment for all types of preeclampsia has been integrated into clinical routine. Interestingly, the last decade has not seen much progress in the quest of identifying the pathophysiological processes resulting in the clinical syndrome preeclampsia. This could be due to the following: (i) the preeclampsia definition has been immensely altered and widened to include a large variety of clinical subgroups; and/or (ii) scientists and clinicians still adhere to the already challenged two-stage hypothesis and give only little room for new hypotheses. These two reasons could have thwarted the deciphering of the etiology of preeclampsia. This review will describe the limitations and challenges of the two-stage hypothesis. It will also highlight some of the new ideas and theories that have been put forward. In conclusion, there is an urgent need for new concepts that allow a better explanation of the diversity of preeclampsia regarding symptoms and time of occurrence. This in turn will result in more options to develop specific predictive biomarkers and personalized treatment options.

Ovarian fibrosis is increasingly recognized as a pivotal factor contributing to ovarian ageing, dysfunction, and female infertility. It results from chronic or repetitive ovarian injury, such as that caused by repeated ovulation, which induces inflammation and excessive extracellular matrix (ECM) deposition, predominantly by activated fibroblasts and myofibroblasts. The key molecular pathways driving ovarian fibrosis include transforming growth factor-beta (TGF-β)/Smad signalling, Wnt/β-catenin, and PI3K/Akt pathways, which orchestrate fibroblast activation, ECM remodelling, and tissue stiffening. Elevated collagen types I and III, fibronectin, and hyaluronan characterize the fibrotic ovarian stroma, disrupting normal folliculogenesis and steroidogenesis. Ovarian fibrosis is also implicated in reproductive pathologies such as polycystic ovary syndrome, premature ovarian insufficiency and endometriosis, and may contribute to an increased risk of ovarian cancer, although definitive causal links require further elucidation. Current therapeutic strategies remain largely experimental, focusing on antifibrotic agents such as pirfenidone, TGF-β inhibitors, and modulation of oxidative stress, alongside emerging interventions such as stem cell therapies, which are offer potential avenues for intervention in the ovary. This review synthesizes current insights into the cellular and molecular mechanisms driving ovarian fibrosis, its association with reproductive disorders, and emerging therapeutic strategies. It underscores key knowledge gaps and emphasizes the need for future research focused on fibroblast activation, inflammatory signalling, and immune-ECM interactions to facilitate the development of targeted, long-term interventions aimed at preventing or reversing ovarian fibrosis and preserving female fertility.

Endometriosis (EM) is a debilitating disease involving the growth of endometrial glands and stroma outside the uterus. To further our understanding of epigenomic dysregulation in EM and search for disease biomarkers, we performed a comprehensive evaluation of DNA methylation in eutopic endometrium (EE) and EM lesions. We undertook deconvolution analysis of DNA methylation data previously generated from endometrial aspirate biopsies obtained from 637 EM cases and 347 controls using microarray-based DNA methylation analysis. We further analyzed DNA methylation in EM lesions and paired EE samples via solution phase hybridization and DNA sequencing. For analysis of microarray data, we used a reference-free approach (BCconf) to recover latent factors and found high correlation with EM status, suggesting EE cell proportions vary between EM cases and controls. Deconvolution revealed that epithelial cells (P-value = 9.1 × 10-3) and fibroblasts (P-value = 0.022) were reduced in EM cases. Deconvolution of the sequencing data identified differences between EM lesions and EE of cases and controls, including vascular endothelial cells (false discovery rate [FDR]-adjusted P-value = 6.1 × 10-3; more abundant in EM lesions), natural killer cells (FDR-adjusted P-value = 0.031; less abundant in EM lesions) and ovarian/endometrial epithelium (FDR-adjusted P-value = 3.2 × 10-3). We detected significant differences in cell type proportion between EE samples of cases and controls. Improved reference data for deconvolution to inform more intelligent region targeting approaches will provide further insight into the molecular phenotype of EM and may inform novel approaches for minimally invasive detection.

Cyclic AMP (cAMP) regulates multiple aspects of sperm function essential for attaining fertilizing ability; therefore, its intracellular levels must be tightly controlled to ensure proper signaling dynamics. In recent years, multidrug resistance-associated protein 4 (MRP4) has emerged as a novel regulator of cAMP homeostasis by facilitating its efflux. Previous studies from our laboratory have identified MRP4 in mammalian sperm and demonstrated its role in capacitation-associated events in murine and bovine species. However, its relevance in human sperm remains unknown. Our study demonstrates a functional MRP4 in human sperm, as its pharmacological inhibition led to a rapid (5 min) intracellular cAMP accumulation and a subsequent decrease in extracellular levels (30 min) under capacitating conditions, as assessed by radio binding protein assay. At the biological level, MRP4 inhibition resulted in a decrease in tyrosine phosphorylation at 360 min of capacitation. Membrane hyperpolarization was also affected, diminishing the induced acrosome reaction. Moreover, a significant reduction in intracellular Ca2+ levels was observed, leading to a significant decrease in progressive and total motility, as well as an inhibition of hyperactivation. In addition, our results indicated that the decrease in Ca2+ levels was due to impaired CatSper channel activity upon MRP4 inhibition. These findings suggest that MRP4-mediated cAMP efflux is essential for proper sperm function, playing a critical role in maintaining nucleotide homeostasis, which is a key determinant in the regulation of human sperm capacitation.