Reproduction最新文献

Reproductive aging in females is characterized by decreased ovarian reserve and oocyte quality. With aging, both mouse and human ovaries become pro-fibrotic and stiff. However, whether follicles sense and respond to microenvironmental stiffness and affect folliculogenesis and oocyte quality independent of other aging-related factors is unknown. To address this question, we cultured mouse secondary follicles in alginate hydrogels that reproduce the stiffness of reproductively young and old mice. RNA-sequencing revealed that follicles respond rapidly to increased stiffness and exhibit enrichment in genes related to inflammation and extracellular matrix remodeling. Long-term culture in stiff hydrogels resulted in reduced follicle survival, granulosa cell viability, estradiol synthesis, and oocyte quality. To begin to determine how stiffness is transmitted within the follicle, we examined transzonal projections, which mediate granulosa cell-oocyte communication and nutrient exchange. In stiff conditions, the number of transzonal projections decreased. Our findings demonstrate that follicles are highly mechanosensitive and that stiffness alone can trigger hallmarks of ovarian aging, including reduced follicle growth, reduced oocyte quality, and a fibroinflammatory phenotype potentially integrated into the oocyte via transzonal projections.

The endocannabinoid system (ECS) plays a crucial role in various physiological processes, including reproduction. Canonical cannabinoid receptors type 1 (CB1) and type 2 (CB2) are activated by 2-acyl glycerol and anandamide, members of a broader endocannabinoid (ECB) lipidome. This study investigated the effect of CB1 receptor signaling on inflammatory mediators and ECS regulation in late pregnancy and its contribution to inflammation-induced preterm birth (PTB) using a murine model. CB1-knock-out (KO) and wild-type (WT) pregnant mice were treated with lipopolysaccharide (LPS) to induce PTB. CB1-KO mice exhibited significantly lower PTB rates compared to WT, suggesting a protective effect of CB1 deficiency. We also analyzed ECS components in decidual tissue and found that CB1-KO displayed lower basal fatty acid amide hydrolase activity than WT. LPS treatment reduced decidual CB2 protein levels only in CB1-KO mice. The pattern of ECBs and related lipids was similar in WT and CB1-KO decidua and serum, with a few key exceptions. Free fatty acids significantly increased in WT decidua with LPS but were unchanged in CB1-KO. Inflammatory markers such as prostaglandin E2, prostaglandin F2α, and matrix metalloproteinase 9 activity were also elevated in WT but not in CB1-KO after LPS administration. These findings suggest that CB1 deficiency modulates endogenous lipids and inflammatory responses during late pregnancy, decreasing the risk of LPS-induced PTB. This study provides new insights into the role of CB1 in pregnancy and its potential as a therapeutic target for PTB prevention.

During the first meiotic division, oocytes inevitably undergo physiological DNA double-strand breaks (DSBs), which are primarily repaired through Bloom (BLM) helicase-mediated homologous recombination repair (HRR). This study investigated the consequences of BLM helicase suppression on meiotic maturation in goat oocytes, revealing that BLM helicase exhibited nuclear-predominant expression over cytoplasmic localization during meiosis I/meiosis II stages and colocalized with spindle fibers. Functional impairment of BLM helicase blocked oocyte maturation, accompanied by dysregulated expression of cumulus expansion-related genes, downregulation of oocyte paracrine factors, elevated reactive oxygen species accumulation, compromised mitochondrial function, upregulated endoplasmic reticulum stress-responsive genes, impaired autophagolysosomal activity, and disrupted Golgi distribution and ribosome function, though mitochondrial fusion and fission remained unaffected. Transcriptomics and reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis further demonstrated that the inhibition of BLM significantly downregulated expression of HRR-associated genes (REC8, PPP4C) while upregulating non-homologous end joining-associated genes (DCLRE1B, ERCC4), suggesting that BLM helicase deficiency may shift DSB repair from HRR to error-prone non-homologous end joining. Consistently, immunofluorescence staining revealed a significant increase in the DNA damage response factor phosphorylated ATM and the repair protein RAD51, indicating that BLM inhibition induces substantial DNA damage in oocytes. These results demonstrate that BLM plays a critical role in maintaining nuclear genomic stability in oocytes. This study highlights BLM helicase as a critical regulator of organelle homeostasis during meiotic progression and provides novel mechanistic insights into its multifaceted roles in oocyte maturation.

Genetic factors significantly influence the timing of menarche and menopause, key markers defining the female reproductive lifespan. However, previous genetic studies have primarily focused on additive genetic models, overlooking potential gene-gene interactions ("epistasis"), particularly within critical hormonal pathways such as follicle-stimulating hormone (FSH) signaling. This study investigates epistasis between common genetic variants in the FSH β-subunit gene (FSHB) and the FSH receptor gene (FSHR), by analyzing their combined impact on female reproductive lifespan. Using data from the UK Biobank, we performed genetic association analysis, including 124,336 White British women with reproductive lifespan data and 36,478 with menstrual cycle length data. Participants were stratified according to genotypes at FSHB rs11031006 (G > A) and FSHR rs6166 (C > T), and associations with reproductive lifespan and menstrual cycle length (categorized as <26, 26-28, >28 days) were tested using linear and ordinal logistic regression, including sub-stratified models to assess non-additive (epistatic) effects. In rs11031006 AA homozygotes, rs6166 C allele dosage was associated with longer menstrual cycles (p = 3.79 × 10-2; odds ratio = 1.24) and an extended reproductive lifespan of up to 7 months (p = 3.57 × 10-2). No significant effects were observed in rs11031006 G allele carriers, revealing a genotype-dependent epistatic interaction. By examining variants of the FSH pathway, we demonstrate how subtle changes in hormone production and receptor responsiveness can interact to yield significant biological effects on menstrual cycle dynamics, ovarian aging, and female reproductive lifespan-ultimately highlighting the need to move beyond purely additive genetic models in reproductive genetics.

Endometriosis, a chronic inflammatory condition characterized by pain and infertility, remains a clinical challenge. Current hormonal and surgical treatments are often limited by side effects and high recurrence rates. In search of more effective and less invasive alternatives, we analyzed a single-cell RNA sequencing dataset of menstrual effluents from patients (GSE203191) and identified a significant upregulation of heat shock protein 90 (HSP90), suggesting its pathogenic involvement. Using primary endometrial stromal cells (ESCs) isolated from human ovarian endometrioma and a murine endometriosis model, we evaluated the therapeutic potential of HSP90 inhibition with 17-allylamino-17-demethoxygeldanamycin (17-AAG). In vitro, 17-AAG (10 nM-10 μM) reduced ESC viability and proliferation in a dose-dependent manner while increasing caspase-3 activity. In vivo, 17-AAG (30 μg/g) significantly attenuated ectopic lesion growth without impairing systemic parameters such as body weight, anti-Müllerian hormone, or estrogen levels. Proteomic profiling revealed disruption of HSP90 client networks, including downregulation of importin 4 and tubulin gamma complex protein 3, and upregulation of DnaJ heat shock protein family member B1, glutamate-ammonia ligase, and sequestosome 1. These findings highlight HSP90 as a promising non-hormonal therapeutic target in endometriosis, offering mechanistic insights and translational potential for more targeted, well-tolerated treatment strategies.

This study investigates whether follicle-stimulating hormone (FSH) induces ferroptosis in TM4 Sertoli cells and mouse testes, and identifies potential mitigating factors. TM4 cells and mice were treated with FSH, and assessments included cell viability, testicular histology, and key ferroptosis markers (ferrous iron, malondialdehyde malondialdehyde, glutathione glutathione). Molecular expression was analyzed via quantitative real-time PCR and western blot. The role of ferroptosis was further examined using the inhibitor ferrostatin-1 (Fer-1). RNA sequencing was employed to explore underlying mechanisms, and functional validation was performed through knockdown and overexpression of the identified regulator, fibroblast growth factor 21 (FGF21). Our results demonstrate that FSH exposure induces ferroptosis in both TM4 Sertoli cells and mouse testes. This is evidenced by decreased protein levels of the ferroptosis suppressors SLC7A11 and FSP1, increased levels of the stress-response proteins FTH1 and HO1, elevated ferrous ion and malondialdehyde content, and reduced glutathione. This ferroptotic cell death may represent a key mechanism contributing to FSH-associated testicular damage. Notably, the ferroptosis inhibitor ferrostatin-1 effectively mitigated this process in TM4 cells. Transcriptomic analysis not only confirmed FSH-induced ferroptosis but also identified FGF21 as a potential modulator. Knockdown of FGF21 promoted ferroptosis, whereas supplementation with exogenous FGF21 alleviated FSH-induced ferroptosis, suggesting a novel inhibitory role for FGF21 in this pathway. In summary, our findings establish that FSH can induce testicular ferroptosis and identify FGF21 as a potential endogenous mitigator of this effect. This highlights FGF21 as a promising therapeutic target for preventing or treating FSH-induced testicular damage.

Preimplantation embryogenesis requires precise synchronization of transcriptional activation, mRNA export and translation, and metabolic reprogramming to sustain developmental requirements. Nuclear cap-binding protein 1 (NCBP1), a conserved subunit of the cap-binding complex, has established roles in mRNA processing and export in somatic cells, but its potential functions in preimplantation embryogenesis remain undefined. The spatiotemporal expression dynamics of Ncbp1 were explored on multiple levels. After microinjecting interfering RNA at zygotic stage to knockdown Ncbp1, embryonic developmental competence was evaluated. Co-injection of small interfering RNA and in vitro transcribed Ncbp1 mRNA into the zygote was used to rescue the knockdown phenotype. Further, poly-adenylated RNA-fluorescence in situ hybridization, RNA sequencing, and quantitative proteomics were used to investigate the effects of Ncbp1 knockdown. In addition, oleic acid (OA) supplementation was used to rescue developmental abnormalities. NCBP1 exhibited dynamic spatiotemporal expression coinciding with nuclear-to-cytoplasmic translocation of protein from morula stage. Depletion of Ncbp1 caused morula arrest or fragmentation, accompanied by nuclear poly-adenylated RNA retention and down-regulation of lipid metabolic pathways, notably, stearoyl-CoA desaturase 1 (SCD1), a key enzyme generating monounsaturated OA. Exogenous OA supplementation partially rescued blastocyst formation, implicating NCBP1 in the regulation of SCD1-OA-mediated metabolic homeostasis during morula-to-blastocyst transition. This study illustrates NCBP1 as a mediator that regulates RNA export and lipid homeostasis during early mouse embryo development. Especially NCBP1 regulates the SCD1-OA metabolic pathways, ensuring metabolic flexibility essential for successful morula-to-blastocyst transition, thereby providing new insights into the molecular basis of embryonic developmental competence.

Uterine smooth muscle undergoes electrical, chemical, and mechanical transients during phasic contraction. The spread of electrical activity precedes the mechanical contraction of muscle fibers, and the initiation and coordination of these events is critical to uterine function, in both pregnancy and non-pregnancy. Characterization of non-pregnant activity is scarce, and understanding of the relationship between electrical and mechanical events is not well understood. Isolated uterine horns from virgin female Wistar rats were used in this study. Electrical and mechanical activity were assessed ex vivo using high-resolution surface electrodes and motion tracking. Electrophysiology data were analyzed to provide frequency and timing metrics; displacement and velocity were quantified from the motion-tracking data. Major coordinated electrical events were correlated with longitudinal displacement of tissue markers, with the peak displacement occurring at or near the point of electrical signal initiation. Overall, 82% of electrical slow wave events were associated with mechanical displacement of tracking points. Minor uncoordinated electrical events were accompanied by little or no displacement, indicating that a level or coordination is required to achieve tissue-level contraction. Electrical slow wave propagation occurred at a higher speed (0.60 ± 0.04 mm/s) than mechanical tissue displacement velocity (0.42 ± 0.39 mm/s, p = 0.0024), and electrical propagation speed was lowest during metestrus when compared with estrus (p = 0.0042) and diestrus (p = 0.0066). This technique advances our understanding of the electro-mechanical properties of the non-pregnant rat uterus and provides an avenue to measure electrical-mechanical coupling in ex vivo uterine tissue preparations.

The pronuclei in human one-cell stage embryos (zygotes) contain several nucleoli called nucleolus precursor bodies (NPBs). Based on their number and distribution, it is possible to predict the developmental potential of the zygote. Recently, it has been demonstrated that the speed of NPBs movement in pronuclei may also indicate how the embryo will develop, as well as its chromosomal constitution (euploidy versus aneuploidy). These observations, however, do not elucidate the mechanisms behind these processes, and a deeper understanding will certainly be important for the more efficient production of healthy human embryos.

Humans and rhesus macaques are known to express two molecular forms of gonadotropin-releasing hormone (GnRH-I and GnRH-II), which appear to differentially contribute to the regulation of the menstrual cycle. Specifically, there is evidence to suggest that GnRH-I is the primary mediator of negative estrogen feedback to the hypothalamus and pituitary gland, while GnRH-II is the primary mediator of the positive feedback that stimulates the preovulatory surge of luteinizing hormone. Therefore, it is plausible that selective silencing of GnRH-II would block ovulation and lay the platform for development of a novel contraceptive. To test this possibility female rhesus macaques were actively immunized against GnRH-II (and/or GnRH-I), and serum estradiol and progesterone concentrations were monitored for an additional ∼2.5 years. Despite multiple booster immunizations every ∼6 weeks, and elevated GnRH antibody titers, none of the animals ceased ovulating (i.e., revealed by monthly peaks of serum progesterone concentrations followed by menstruation). Taken together, these findings question the efficacy of GnRH vaccines as a stratagem for selectively blocking ovulation in humans. However, they do not negate the potential value of pharmacological interventions aimed at selectively silencing GnRH-II function and its involvement in stimulating the preovulatory luteinizing hormone surge.