Biology of Reproduction最新文献

In vitro oocyte maturation (IVM) is a vital step for many assisted reproductive technologies including in vitro embryo production. Modulation of ribonucleic acid (RNA) transcripts, lipids, mitochondria, and other molecules during maturation influences development significantly. To improve current maturation systems, inclusion of pre-maturation culture has been investigated to delay resumption of meiosis and allow appropriate progression of cytoplasmic maturation using C-type natriuretic peptide (CNP). In this study, the transcriptome and molecular fingerprint of germinal vesicle, conventional IVM, and CNP-IVM oocytes were compared to identify transcripts and associated pathways altered by CNP treatment. There were similar pathways associated with upregulated transcripts in both types of mature oocytes involved with mitochondrial function and translation. Oocytes that were matured under conventional conditions contained transcripts associated with messenger RNA surveillance, Polycomb repressive complex, and reactive oxygen species. Oocytes matured with CNP treatment contained transcripts associated with cofactor biosynthesis, autophagy, apoptosis, arginine and proline metabolism, and mechanistic target of rapamycin (mTOR). Compared to immature oocytes, all mitochondrial-derived protein encoding genes were upregulated after conventional IVM but not after CNP-IVM. The molecular fingerprint of lipid droplets was also significantly altered in CNP-treated oocytes. Overall, results of these experiments have demonstrated measurable transcriptomic and molecular differences in CNP treated oocytes that may enhance oocyte and embryo quality.

Global warming poses a public health risk, and heat-induced reproductive defects are a growing concern for both humans and animals. Disrupted estrous cycle and reduced estrogen synthesis are notable changes in females exposed to heat stress; however, the underlying mechanism remains largely unknown, thus effective preventive or interventional strategies are still lacking. Here, by focusing on Cyp19a1, the gene encoding the rate-limiting enzyme for estrogen synthesis in ovarian granulosa cells, we identify heat stress as a trigger for Ca2+ release from the endoplasmic reticulum (ER). The increased intracellular Ca2+ flux functions as a high-temperature sensor and activates STAT3 phosphorylation. The activated Ca2+-pSTAT3 cascade disrupts the expression of H3K27me3-modifying enzymes, thus elevating H3K27me3 levels and finally represses Cyp19a1. Moreover, we demonstrate that retinoic acid (RA), the primary active metabolite of vitamin A, rescues CYP19A1 expression by antagonizing heat stress on multiple layers of the cascade. In vivo, RA administration rescues estrogen synthesis and corrects the estrous cycle in female mice under heat stress. Together, our study establishes a mechanistic link between heat stress and impaired estrogen synthesis and identifies the antagonistic function of RA. Finally, we propose a nutritional strategy to prevent or alleviate high temperature-induced estrus disorders in females.

Parvalbumins (Pvalb) are members of the EF-hand protein superfamily which have been shown to play important roles in the nervous system and muscle. In the present study, the expression and potential roles of parvalbumin 5 (Pvalb5), a member of Parvalbumin subfamily, was characterized in a teleost the ricefield eel. RT-PCR analysis revealed a very restricted tissue distribution of pvalb5 mRNA, with dominant expression in the pituitary and eye of both female and male ricefield eels. Specific antisera against ricefield eel Pvalb5 were generated, and immunohistochemical analysis showed the presence of Pvalb5 in the adenohypophysis of adult fish but not of juveniles (about 4-month-old). Dual immunofluorescent immunostaining indicated the expression of Pvalb5 in Fsh cells but not in other pituitary tropic hormone-producing cells including Lh, Tsh, Gh, or Prl. Overexpression of pvalb5 increased Fsh release but not Lh release in primary pituitary cells. Results of the present study suggest that Pvalb5 may be specifically involved in the regulation of Fsh release in the pituitary of ricefield eels, which advances our understanding of the mechanisms underlying the differential regulation of Fsh and Lh release in vertebrates.

Phthalates are widely used plasticizers that leach into the environment and have impacts on health and fertility of humans and animals. Among these ubiquitous environmental contaminants is diisobutyl phthalate (DiBP), a plasticizer known to affect fetal murine reproductive organs during prenatal exposure. However, studies investigating whether DiBP influences mammalian postpubertal ovarian function are lacking. In the present study, we tested the hypothesis that DiBP influences the function of bovine granulosa cells. Furthermore, we investigated the impacts of DiBP on expression of genes associated with ovarian steroidogenesis, DNA methylation, RNA methylation, histone acetylation, and inflammation. Bovine granulosa cells were treated with various doses of DiBP (0, 1, 10, and 100 ng/mL) combined with FSH or FSH plus IGF1 from 24 to 48 h. In combination with FSH, various doses of DiBP influenced the expression of genes associated with histone acetylation. In combination with FSH plus IGF1, DiBP at 10 ng/mL decreased synthesis of estradiol and expression of genes associated with RNA m6A methylation, RNA m5C methylation, and inflammation in comparison to the negative control (0 ng/mL DiBP) group. Taken together, these findings show that DiBP alters the function of granulosa cells of cattle, a mono-ovulatory species, at environmentally important doses and may impair mammalian fertility via inflammatory and epigenetic mechanisms.

Cervical remodeling (CR) is essential for pregnancy maintenance and successful parturition, yet its molecular regulation in humans remains incompletely defined. This study aimed to present a high-resolution, longitudinal proteomic atlas of the human CR across normal gestation. A retrospective study was conducted using cervical tissue samples collected during nonpregnancy and at three trimesters. The study cohort included 10 healthy controls and 31 pregnant women with uncomplicated singleton pregnancies. Proteomic analyses were performed using data-independent acquisition mass spectrometry. Then, we carried out comparative proteomic analyses across adjacent gestational stages and unsupervised clustering of all quantified proteins based on their expression dynamics. Subsequently, we systematically characterized the dynamic regulation of collagen. Finally, protein-protein interaction networks based on temporally regulated proteins were constructed. We quantified 6092 proteins, revealing stage-specific shifts in immune regulation, extracellular matrix remodeling, and hormone responsiveness. Systematic evaluation of five canonical hypotheses for functional progesterone withdrawal identified receptor downregulation and hormone-binding protein sequestration as the dominant mechanisms within cervical tissue. Collagen composition and organization were progressively disrupted, accompanied by coordinated remodeling of hyaluronan, enzymatic expression levels, and elastic fiber components. Network-based analyses uncovered modular regulatory architectures and stage-specific rewiring of protein interactions. Finally, we infer fibronectin 1 (FN1), matrix-metalloproteases 9 (MMP9) and estrogen receptor 1 (ESR1) protein as central regulator molecules for CR. Our study provides a temporal framework to dissect stage-specific molecular events that drive CR. These findings establish a comprehensive proteomic framework for understanding human CR and highlight novel targets for predicting and modulating CR disorders.

Premature ovarian insufficiency (POI), a major cause of female infertility, is a condition where the ovaries lose their function before the age of 40. Growing evidence suggests that Lysine acetyltransferase 2A (KAT2A) has been identified as a critical factor for mammalian development and the maintenance of genome stability, and is associated with aging. However, the function of KAT2A in POI remains unclear. Our objective was to elucidate the role of KAT2A in the progression of POI and the intricate underlying mechanisms involved. KAT2A expression was significantly increased in human granulosa cells (hGCs) isolated from POI patients, as well as in the ovaries of aged mice. KAT2A overexpression aggravated estrous cyclicity irregularity, hormonal imbalances, follicular development disorders, increased follicular atresia, and decreased ovarian reserve in mice. Meanwhile, KAT2A overexpression exacerbates reactive oxygen species (ROS)-induced cellular apoptosis in mouse GCs (mGCs). Mechanistically, gene set enrichment analysis revealed that KAT2A upregulation significantly enriched apoptosis and p38 mitogen-activated protein kinase (MAPK) signaling pathway. Using a p38/MAPK-specific inhibitor in rescue experiments confirmed that the inhibit of p38/MAPK is essential for KAT2A-mediated ovarian dysfunction. In summary, the current study elucidated the molecular network of KAT2A- p38/MAPK in pathogenesis of POI, thereby implying it to be a potential therapeutic target for female reproductive aging.

Fertility in mammals is influenced by the interaction between spermatozoa and the female reproductive tract. While sperm has traditionally been regarded as passive carriers of paternal DNA, there is growing evidence that they actively influence the oviductal environment. In cattle and other species, a subpopulation of sperm binds to epithelial cells in the isthmus, forming a reservoir that prolongs viability, modulates capacitation, and ensures a timed release of competent cells. This adhesion involves multiple mechanisms, including recognition of specific glycans such as fucosylated residues, protein-protein interactions, and binding between integrins and fibronectin. Beyond mechanical anchoring, these contacts initiate signaling cascades within the epithelium. Ciliated cells transmit signals to secretory cells, leading to transcriptomic remodeling and changes in protein and extracellular vesicle secretion. As a result, the luminal fluid becomes enriched with cytokines, antioxidants, and immunomodulatory factors that help maintain sperm function under oxidative and immune pressure. Interestingly, the oviduct also appears capable of discriminating between spermatozoa of different quality or those subject to sexing procedures, although the precise molecular mediators remain poorly defined. This selective response suggests that sperm interact with maternal regulatory mechanisms and may represent one of several contributors to oviductal plasticity, together with endocrine, oocyte- and embryo-derived signals. From an applied perspective, a deeper understanding of these mechanisms may help to refine assisted reproductive technologies, by improving in vitro fertilization media or developing functional assays for sire fertility. Despite recent progress, much remains to be clarified regarding how sperm-derived signals are sensed and integrated by the oviduct.

Human embryo implantation is crucial for successful pregnancy, yet its molecular mechanisms remain poorly understood due to ethical and technological limitations. In this study, we constructed an embryo implantation model using single-cell RNA sequencing (scRNA-seq) data from the implantation sites (ISs) of patients with tubal ectopic pregnancy (TEP) to infer the embryo implantation mechanisms at the maternal-fetal interface during early human pregnancy. Based on scRNA-seq data from normal intrauterine pregnancies (IUP) in the public database (GSE214607), we identified and validated marker genes for trophoblast cells and their subtypes. We applied CellPhoneDB and CellChat to map intercellular communication networks at the maternal-fetal interface in the TEP model. By validating the predicted ligand-receptor interacting pairs against IUP data, we assessed the utility of the TEP model as a reference for studying implantation mechanisms. Results revealed similar gene expression patterns at the transcriptional level between trophoblast cells in TEP and IUP, and Immunofluorescence staining further supported the conserved expression of key marker genes in the two types of pregnancy tissues. Cell-cell interaction analysis suggested bidirectional ligand-receptor communications between extravillous trophoblasts (EVTs) and non-ciliated secretory epithelial cells, involving extracellular matrix remodeling, angiogenesis, and immune regulation. Meanwhile, macrophages may participate in trophoblast-immune interactions through the IL-1 signaling pathway. These signaling pathways showed a certain degree of conservation between TEP and IUP. The TEP model provides a complementary tool for studying early implantation, offering new perspectives for elucidating molecular mechanisms at the maternal-fetal interface and for preventing and treating infertility.

During mammalian gametogenesis, the chromatin landscape is especially dynamic. Primordial germ cells (PGCs), the precursors to mature male and female gametes, are a transient and small cell population that undergoes profound epigenetic reprogramming. Our knowledge of this process has come primarily from descriptive studies of mouse and human PGCs, and functional studies in mouse. Now, advances in both epigenetic profiling and in vitro gametogenesis are facilitating more in-depth study of germ cell chromatin. Here, we review these findings in the broader context of chromatin dynamics in mouse and human PGCs.

Recent findings highlight NAD+ as a central regulator of various cellular processes, including energy metabolism, stress response, and aging. Growing evidence of the benefits associated with dietary NAD+ precursors has elevated NAD+ to a promising therapeutic target for addressing female infertility. This review aims to evaluate existing literature on the mechanisms governing the availability and utilization of NAD+ in the ovaries and its alterations in female reproductive disorders, with a particular focus on ovarian aging and dysfunction including polycystic ovary syndrome and premature ovarian insufficiency. Alongside data from in vivo and in vitro studies on various NAD+ boosters, this review incorporates findings from research on genetic mutations, polymorphisms in human and animal populations, and insights from transgenic animal models. The present work emphasizes that NAD+ deficiency is largely driven by a combination of factors, including heightened consumption, impaired utilization efficiency, and diminished biosynthesis or transport. Based on this analysis, we suggest that the ovary possesses its own unique NAD+ metabolism, but our understanding of its regulatory mechanisms is still in its infancy. Key questions remain unanswered, such as how NAD+ and its precursors are transported into oocytes and ovarian cells, their specific preferences for different NAD+ precursors, as well as the specific changes associated with different ovarian dysfunctions. Finally, we reviewed methods for studying NAD+ metabolism as essential tools for investigating the potential of NAD+ boosting therapies to counteract ovarian aging and dysfunction.