Biology of Reproduction最新文献

Hormonal contraceptives modulate the hypothalamic-pituitary-ovarian (HPO) axis; however, underlying mechanisms and differences between contraceptives are underexplored. The Women's Health Injectable Contraception and HIV trial randomised 521 women to intramuscular depot medroxyprogesterone acetate (DMPA-IM) or norethisterone enanthate (NET-EN) and showed similar decreased estradiol levels, but more amenorrhea for DMPA-IM users. This secondary study excluded for misreporting contraceptive use for 128 participants (DMPA-IM n = 65; NET-EN n = 63). Peripheral blood serum collected at initiation and one week after the 24-week injection (25 W), at peak progestin levels, was analysed for gonadal steroids, progestins and peptide hormones. While no changes were detected in peripheral gonadotropin-releasing hormone levels, DMPA-IM decreased luteinising hormone (LH) less than NET-EN. DMPA-IM increased, while NET-EN decreased follicle-stimulating hormone (FSH). Both contraceptives substantially decreased gonadal steroid levels, more so in NET-EN users for testosterone and estradiol. Post-menopausal-like hypoestrogenic effects were greater than previously reported, consistent with the substantial reduction in LH levels. Whether reduced LH levels are due to direct pituitary, hypothalamic, or supra-hypothalamic effects by progestins, is unclear. MPA, unlike NET, increased fsh expression in LβT2 cells, likely via the glucocorticoid receptor, consistent with direct effects on the pituitary by MPA in women. Amenorrhea associated in a time-varying manner with MPA and HPO hormone levels and LH/FSH, for DMPA-IM but not NET-EN users. HPO hormone profiles differ between DMPA-IM and NET-EN users and compared to pre- and post-menopausal women. Mechanisms affecting amenorrhea likely differ between contraceptives, with lower 25 W LH/FSH being consistent with more amenorrhea for DMPA-IM.

The endometrium is a hormonally responsive tissue that undergoes cyclic remodeling. Although endometrial organoids have been established in several species, detailed characterization remains limited. Here, we assessed the structural and molecular fidelity of equine endometrial organoids across reproductive cycle stages and during extended culture. Organoids were generated from biopsies collected during estrus and diestrus and analyzed using histology, immunohistochemistry, electron microscopy, and bulk- and single-cell RNA sequencing. Organoids formed polarized cystic structures composed of columnar cells with microvilli, tight junctions, and secretory vesicles. Compared to native tissue, organoids showed higher expression of genes involved in proliferation and metabolism, and lower expression of genes related to differentiation, angiogenesis, and immune responses. Single-cell analysis identified diverse epithelial and stromal populations in both tissue and organoids. While most cell types were preserved, organoids were enriched in progenitor-like cells but underrepresented in ciliated, proliferative glandular, endothelial, smooth muscle, and antigen-presenting cells. Cycle-specific differences were observed in morphology, hormone receptor expression, and gene expression profiles. Estrus-derived organoids showed increased proliferation and metabolic activity. Although organoids retained transcriptional signatures reflective of the hormonal cycle stage of the source tissue, these signatures faded with prolonged culture, despite overall transcriptomic stability. In summary, equine endometrial organoids replicate key features of the native tissue, retain reproductive cycle characteristics, and maintain transcriptomic stability over time. Endometrial organoids provide a robust platform to study the equine endometrium, though native tissue differences should be considered in the experimental design and data interpretation.

Transforming growth factor-beta (TGF-β) supports the in vitro maintenance of embryonic and trophoblast stem cells. Here, we demonstrated that, in a sheep embryo model, the transition from morula to blastocyst is positively regulated by TGF-β3, primarily through its promotion of trophoblast development. Our results indicate that morulae treated with TGF-β3 develop at a higher rate into blastocysts, characterized by an expanded trophoblast layer marked by CDX-2 expression. In blastocysts, TGF-β3 mediates transcriptional activation of genes involved in cell adhesion and lipid metabolism pathways, leading to remarkable in vitro outgrowth expansion and a substantial increase in trophoblast lipid droplet content. Functional analysis reveals that the positive effects of TGF-β3 are mitigated by inhibition of Acetyl-CoA Synthetase Short-Chain Family Member 2 (ACSS2), a key enzyme upregulated by TGF-β3 and a promoter of de novo lipogenesis. These findings suggest that TGF-β3 modulates lipid metabolism during blastocyst formation and may play a potential role in regulating implantation and placental development.

Intrauterine adhesion (IUA) is an adhesion of the uterine cavity or cervical canal resulting from damage to the basal layer of the endometrium， usually accompanied by fibrosis of the endometrium. This study analyzed endometrial samples from three IUA patients and three healthy control participants and screened for differentially expressed genes (DEGs) using RNA-seq and bioinformatics techniques. A total of 2402 DEGs were identified in endometrial tissues compared to normal endometrial tissues, among which microfibrillar-associated protein 5 (MFAP5) was upregulated in IUA tissues (log2FoldChange = 3.81, P = 1.98E-08). Meanwhile, clinical tissue specimens revealed remarkably up-regulated MFAP5 expression in endometrial tissues of IUA patients, accompanied by increases in the fibrosis markers collagen type I A 1 and α-smooth muscle actin. A mouse model of IUA was constructed by mechanical curettage. Histopathology revealed that MFAP5 downregulation attenuated IUA model-induced reduction in endometrial gland number and collagen deposition. Furthermore, MFAP5 knockdown alleviated the increase in embryo uptake ratio and the decrease in embryo and placental weight in IUA model. In vitro, the expression of fibrosis indicators was upregulated in Ishikawa cells treated with 5 ng/mL transforming growth factor-β1 (TGF-β1), while MFAP5 siRNA reduced levels of the endometrial fibrosis markers. RNA-seq analysis was performed on normal-treated and MFAP5 knockdown-treated TGF-β1-induced cell lines. Enrichment analysis revealed that the MFAP5 siRNA may be involved in microfibril formation, collagen deposition, and the TGF-β pathway. These results further confirm the potential role of MFAP5 in promoting endometrial fibrosis, which provides new insight for the clinical treatment of IUA.

The maternal-fetal interface comprises trophoblast cells, immune cells, decidual cells, and various other cellular components that collectively contribute to the maintenance of 1immune homeostasis through the secretion of specific cytokines and hormones. Inflammation plays a crucial role in successful embryo implantation, pregnancy maintenance, and parturition; however, it also exhibits a dual role in reproduction and pregnancy. Excessive activation of inflammatory processes, conversely, may have detrimental effects on pregnancy outcomes. Research has demonstrated that elevated levels of High Mobility Group Box 1 (HMGB1) in maternal circulation correlate with negative pregnancy outcomes, including unexplained recurrent miscarriage, gestational diabetes, and preeclampsia (PE). Furthermore, HMGB1 functions by activating the NF-κB signaling pathway through its interaction with the receptor for advanced glycation end-products (RAGE) and Toll-like receptors (TLRs), which subsequently enhances the expression of downstream pro-inflammatory cytokines such as IL-18, interleukin-1 beta (IL-1β), and TNF-α, thereby contributing to adverse pregnancy outcomes. Collectively, this evidence positions HMGB1 as a potential biomarker for these negative pregnancy results. This review aims to elucidate the mechanisms by which HMGB1 acts as an inflammatory regulatory factor in various adverse pregnancy outcomes and to investigate the potential therapeutic value of HMGB1 antagonists as candidate agents for the prevention and treatment of preterm birth (PB) and inflammatory damage, thereby providing a theoretical foundation for developing intervention strategies targeting HMGB1.

Exposure to testosterone (T) in pregnant ewes resulted in placental dysfunction and fetal growth restriction (FGR). However, the impact of T on gut microbiota and its contribution to exacerbating intestinal and placental pathologies remains uncharacterized. Pregnant sheep received intramuscular injections of 100 mg T propionate or a control vehicle. To examine the gut microbiota' s role in T-induced FGR, gut microbiota transplantation (GMT) was conducted from T-exposed and control ewes into antibiotic-treated pregnant mice. The findings demonstrated that T exposure exacerbated mitochondrial impairment, autophagy, and ferroptosis in placental and intestinal tissues, alongside inducing gut microbial dysbiosis. GMT further revealed that pathological alterations were mechanistically linked to gut microbiota imbalance. The findings demonstrated that gut-placental axis play a central role in mediating T-induced mitochondrial dysfunction, autophagy, and ferroptosis in maternal intestinal and placental tissues. These results underscore novel therapeutic opportunities, which operate via the gut-placental axis to mitigate FGR.

Maternal stress caused by the environmental factors varied in intrauterine and extrauterine during pregnancy may significantly affect placental and fetal development, as well as offspring health in adulthood. Epigenetic mechanisms are frequently invoked to elucidate these effects. RNA N6-methyladenosine (m6A) modification, one of the most prevalent and abundant post-transcriptional epigenetic modifications in eukaryotic mRNA, has recently garnered widespread attention in life sciences. RNA m6A modification plays critical roles in RNA splicing, translation, localization, stability, and has been implicated in various biological processes, including embryonic development, sex determination, and disease pathogenesis. In studies of placental developmental abnormalities induced by maternal stress during pregnancy, m6A modification has emerged as a key mechanism. This article initially introduces the impact of RNA m6A methylation modification on placental development, subsequently elaborates on recent advances in understanding how maternal stress induces placental abnormalities via m6A modification, and finally summarizes unresolved key questions in this field. This review aims to propose strategies for preventing and treating placental developmental abnormalities caused by maternal stress.

Pain tolerance varies significantly among humans, with disparities attributable to genetic factors and environmental influences. The developmental origins of health and disease approach postulate that pre- and early postnatal maternal environment affects individuals' health and well-being. In the present study, we aimed to determine the influence of prenatal and early postnatal maternal environment and care on the offspring's physiology and pain response. To this end, we analysed the influence of bidirectional embryo transfer (ET) and cross-fostering (CF) between two mouse lines divergently selected for high (HA) and low (LA) swim stress-induced analgesia (SSIA) on offspring phenotype, SSIA-related traits and opioid component of SSIA. Our findings reveal that both the fetal development and early maternal care significantly influence the level of SSIA in mice. HA mice born after ET to LA surrogate mothers showed reduced SSIA levels alongside a diminished effect of the opioid antagonist naloxone, suggesting a decreased opioid component in SSIA regulation. This effect was preserved in the F2 generation of individuals originating from ET, but not CF. Additionally, both ET and CF resulted in changes in body weight and body temperature towards an average value of the surrogate or foster maternal line; however, these changes were not preserved in the F2 generation. Together, our findings indicate that maternal influence during fetal development and the early postnatal period may influence physiological parameters, as well as traits associated with stress response. Maternal influence is more pronounced in progeny subject to ET, indicating a stronger influence of the prenatal period.

KIT signaling is a fundamental regulatory pathway that preserves cellular homeostasis and controls cell development and fate across a wide range of organs and cell types. Consistent with this pleiotropic role, mutations in c-KIT/Kit have been associated with a wide range of phenotypes, including sterility, piebaldism, nevus formation, mastocytosis, and multiple malignancies. The contribution of c-KIT/Kit to reproductive function has attracted sustained attention for several decades, underscoring its essential role in fertility and gonadal biology. KIT expression is observed in oocytes - localized to the oocyte membrane and the cytoplasm - as well as in theca cells and interstitial cells, suggesting a multifaceted role in follicular development. Notably, all Kit mutant models develop primary ovarian insufficiency (POI) with variable onset, characterized by endocrine dysfunction, impaired folliculogenesis, and eventual female infertility. These findings collectively establish KIT signaling as a critical regulator of ovarian integrity, as both gain- or loss-of-function mutations in Kit consistently recapitulate POI-associated phenotypes. However, despite substantial progress, the precise molecular mechanisms by which KIT signaling integrates these pathways to preserve primordial follicle survival and prevent POI remain incompletely understood. Here, we summarize current knowledge of KIT expression and the functional consequences of Kit mutations, with particular emphasis on oocytes across ovarian cell populations and in comparison to other organ systems in humans and mice. We further evaluate the physiological and pathological significance of ovarian KIT signaling in female fertility and highlight crucial knowledge gaps that must be addressed to fully elucidate its role in maintaining ovarian function.