Search Results (224)

The activation mechanism of the reproductive axis in Kazakh ewes during the non-breeding season was explored by supplementation with glycerol complex (7% glycerol + tyrosine + vitamin B9). The experiment divided 50 ewes into five groups (n = 10). After 90 days of intervention, it was found that significant changes in serum DL-carnitine, N-methyl-lysine and other differential metabolites were observed in the GLY-Tyr-B9 group (p < 0.05, “p < 0.05” means significant difference, “p < 0.01” means “highly significant difference”). The bile acid metabolic pathway was specifically activated (p < 0.01). The group had a 50% estrus rate, ovaries contained 3–5 immature follicles, and HE staining showed intact granulosa cell structure. Serum E2/P4 fluctuated cyclically (p < 0.01), FSH/LH pulse frequency increased (p < 0.01), peak Glu/INS appeared on day 60 (p < 0.05), and LEP was negatively correlated with body fat percentage (p < 0.01). Molecular mechanisms revealed: upregulation of hypothalamic kiss-1/GPR54 expression (p < 0.01) drove GnRH pulses; ovarian CYP11A1/LHR/VEGF synergistically promoted follicular development (p < 0.05); the HSL of subcutaneous fat was significantly increased (p < 0.05), suggesting involvement of lipolytic supply. Glycerol activates the reproductive axis through a dual pathway—L-carnitine-mediated elevation of mitochondrial β-oxidation efficacy synergizes with kisspeptin/GPR54 signalling enhancement to re-establish HPO axis rhythms. This study reveals the central role of metabolic reprogramming in regulating seasonal reproduction in ruminants. Full article

Background: Polycystic ovary syndrome (PCOS) is a complex and multifactorial disorder affecting reproductive, endocrine, and metabolic functions in women of reproductive age. While environmental and lifestyle factors play a role, increasing evidence highlights the contribution of genetic and epigenetic mechanisms to its pathogenesis. Objective: This narrative review aims to provide an updated overview of the current evidence regarding the role of genetic variants, gene expression patterns, and epigenetic modifications in the etiopathogenesis of PCOS, with a focus on their impact on ovarian function, fertility, and systemic alterations. Methods: A comprehensive search was conducted across MEDLINE, EMBASE, PubMed, Web of Science, and the Cochrane Library using MeSH terms including “PCOS”, “Genes involved in PCOS”, and “Etiopathogenesis of PCOS” from January 2015 to June 2025. The selection process followed the SANRA quality criteria for narrative reviews. Seventeen studies published in English were included, focusing on original data regarding gene expression, polymorphisms, and epigenetic changes associated with PCOS. Results: The studies analyzed revealed a wide array of molecular alterations in PCOS, including the dysregulation of SIRT and estrogen receptor genes, altered transcriptome profiles in cumulus cells, and the involvement of long non-coding RNAs and circular RNAs in granulosa cell function and endometrial receptivity. Epigenetic mechanisms such as the DNA methylation of TGF-β1 and inflammation-related signaling pathways (e.g., TLR4/NF-κB/NLRP3) were also implicated. Some genetic variants—particularly in DENND1A, THADA, and MTNR1B—exhibit signs of positive evolutionary selection, suggesting possible ancestral adaptive roles. Conclusions: PCOS is increasingly recognized as a syndrome with a strong genetic and epigenetic background. The identification of specific molecular signatures holds promise for the development of personalized diagnostic markers and therapeutic targets. Future research should focus on large-scale genomic studies and functional validation to better understand gene–environment interactions and their influence on phenotypic variability in PCOS. Full article

The hypothalamus–pituitary–ovarian (HPO) axis orchestrates reproductive functions through intricate neuroendocrine crosstalk. Here, we integrated single-nucleus RNA sequencing (snRNA-seq) and spatial transcriptomics (ST) to decode the cellular heterogeneity and intercellular communication networks in the reproductive systems of pregnant Mongolian cattle. We retained a total of 6161 high-quality nuclei from the hypothalamus, 14,715 nuclei from the pituitary, and 26,072 nuclei from the ovary, providing a comprehensive cellular atlas across the HPO axis. In the hypothalamus, neurons exhibited synaptic and neuroendocrine specialization, with glutamatergic subtype Glut4 serving as a TGFβ signaling hub to regulate pituitary feedback, while GABAergic GABA1 dominated PRL signaling, likely adapting maternal behavior. Pituitary stem cells dynamically replenished endocrine populations via TGFβ, and lactotrophs formed a PRL–PRLR paracrine network with stem cells, synergizing mammary development. Ovarian luteal cells exhibited steroidogenic specialization and microenvironmental synergy: endothelial cells coregulated TGFβ-driven angiogenesis and immune tolerance, while luteal–stromal PRL–PRLR interactions amplified progesterone synthesis and nutrient support. Granulosa cells (GCs) displayed spatial-functional stratification, with steroidogenic GCs persisting across pseudotime as luteinization precursors, while atretic GCs underwent apoptosis. Spatial mapping revealed GCs’ annular follicular distribution, mediating oocyte–somatic crosstalk, and luteal–endothelial colocalization supporting vascularization. This study unveils pregnancy-specific HPO axis regulation, emphasizing multi-organ crosstalk through TGFβ/PRL pathways and stem cell-driven plasticity, offering insights into reproductive homeostasis and pathologies. Full article

Background: Against the backdrop of the large-scale and intensive development of the livestock industry, enhancing the reproductive efficiency of cattle has become a crucial factor in industrial development. Holstein cows, as the most predominant dairy cattle breed globally, are characterized by high milk yield and excellent milk quality. However, their reproductive efficiency is comprehensively influenced by a variety of complex factors, and improving their reproductive performance faces numerous challenges. The ovary, as the core organ of the female reproductive system, plays a decisive role in embryonic development and pregnancy maintenance. It is not only the site where eggs are produced and developed but it also regulates the cow’s estrous cycle, ovulation process, and the establishment and maintenance of pregnancy by secreting various hormones. The normal functioning of the ovary is crucial for the smooth development of the embryo and the successful maintenance of pregnancy. Methods: Currently, traditional sequencing technologies have obvious limitations in deciphering ovarian function and reproductive regulatory mechanisms. To overcome the bottlenecks of traditional sequencing technologies, this study selected Holstein cows as the research subjects. Ovarian samples were collected from one pregnant and one non-pregnant Holstein cow, and single-nucleus transcriptome sequencing technology was used to conduct an in-depth study on the ovarian cells of Holstein cows. Results: By constructing a cell type-specific molecular atlas of the ovaries, nine different cell types were successfully identified. This study compared the proportions of ovarian cell types under different physiological states and found that the proportion of endothelial cells decreased during pregnancy, while the proportions of granulosa cells and luteal cells increased significantly. In terms of functional enrichment analysis, oocytes during both pregnancy and non-pregnancy play roles in the “cell cycle” and “homologous recombination” pathways. However, non-pregnant oocytes are also involved in the “progesterone-mediated oocyte maturation” pathway. Luteal cells during pregnancy mainly function in the “cortisol synthesis and secretion” and “ovarian steroidogenesis” pathways; non-pregnant luteal cells are mainly enriched in pathway processes such as the “AMPK signaling pathway”, “pyrimidine metabolism”, and “nucleotide metabolism”. Cell communication analysis reveals that there are 51 signaling pathways involved in the pregnant ovary, with endothelial cells, granulosa cells, and luteal cells serving as the core communication hubs. In the non-pregnant ovary, there are 48 pathways, and the interaction between endothelial cells and stromal cells is the dominant mode. Conclusions: This study provides new insights into the regulatory mechanisms of reproductive efficiency in Holstein cows. The differences in the proportions of ovarian cell types, functional pathways, and cell communication patterns under different physiological states, especially the increase in the proportions of granulosa cells and luteal cells during pregnancy and the specificity of related functional pathways, indicate that these cells play a crucial role in the reproductive process of cows. These findings also highlight the importance of ovarian cells in pathways such as “cell cycle”, “homologous recombination”, and “progesterone-mediated oocyte maturation”, as well as the cell communication mechanisms in regulating ovarian function and reproductive performance. Full article

Organ functions generally decline with age, but the ovary is a prototypical organ that undergoes functional loss over time. Autophagy plays a crucial role in maintaining organ homeostasis, and age-related upregulation of the autophagy inhibitor protein, Rubicon, has been linked to cellular and tissue dysfunction. This review describes how granulosa cell autophagy supports follicular growth and oocyte selection and maturation by regulating cellular energy metabolism and protein quality control. We then introduce the role of selective autophagy, including mitophagy or lipophagy, in steroidogenesis and cellular remodeling during luteinization. In aged ovaries, Rubicon accumulation suppresses autophagic flux, leading to diminished oxidative-stress resilience and enhanced DNA damage. Moreover, impaired autophagy drives the accumulation of ATP citrate lyase, which correlates with poor oocyte quality and reduced ovarian reserve. Following fertilization, oocytes further upregulate autophagy to provide the energy required for blastocyst transition. Conversely, in infertility-related disorders, such as premature ovarian insufficiency, endometriosis, and polycystic ovary syndrome, either deficient or excessive autophagy contributes to disease pathogenesis. Both autophagy inhibitors (e.g., Rubicon) and activators (e.g., Beclin1) could be emerging as promising biomarkers for assessing ovarian autophagy status. Therapeutically, Rubicon inhibition by trehalose in aged ovaries and autophagy suppression by agents such as hydroxychloroquine in polycystic ovary syndrome and endometriosis hold potential. Establishing robust methods to evaluate ovarian autophagy will be essential for translating these insights into targeted treatments. Full article

The accumulation of nanoparticles (NPs) in the female body has raised global concerns regarding potential effects on the reproductive system. This study aimed to investigate the toxic effects of nano-titanium dioxide (nano-TiO₂) exposure on the ovaries and the underlying mechanisms. By establishing a nano-TiO₂ accumulation model in mice, our research systematically evaluated the effects of different concentrations of nano-TiO₂ exposure on the development and reproductive endocrine functions of mice. The results showed that nano-TiO₂ exposure significantly reduced the littering rate, sex hormone levels, and ovarian index of mice, and the effects were dose-dependent. Studies on the mechanisms involved revealed that nano-TiO₂ induces an excessive production of reactive oxygen species (ROS), leading to the potential collapse of the mitochondrial membrane and an increase in the apoptosis rate of granulosa cells, thereby triggering oxidative stress and inhibiting the expression of ovarian-specific genes and granulosa-cell function genes. This study reveals the “dual blow” mechanism of nano-TiO₂-mediated ovarian morphology and function through oxidative stress in granulosa cells, namely directly disrupting cellular homeostasis and interfering with the reproductive-related gene network, ultimately leading to decreased ovarian function. This provides experimental evidence for assessing the reproductive risks of nanomaterials in women. Full article

The normal development of ovarian follicles, characterized by oocyte growth and granulosa cell proliferation, is essential for maintaining female fertility. Elevated oxidative stress, resulting from various in vivo and in vitro factors, significantly impairs follicular development, ovulation, and overall female fertility. Swertiamarin, a naturally occurring iridoid terpenoid compound, exhibits multiple beneficial properties, including anti-hyperlipidemic, anti-diabetic, and antioxidant effects. This study investigates the impact of Swertiamarin on follicular development impairment induced by oxidative stress, using the commonly applied oxidant 3-nitrophthalic acid (3-NPA) in a murine model. Our findings indicate that Swertiamarin administration mitigates the adverse effects of 3-NPA on follicular development and ovulation. Further analyses reveal that Swertiamarin treatment partially enhances granulosa cell proliferation and inhibits apoptosis under oxidative stress in vivo and in vitro. Moreover, Swertiamarin reduces oxidative stress in ovaries and granulosa cells exposed to 3-NPA. The expression levels of key members of the NRF2/HO-1 signaling pathway, including nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (Ho-1), and superoxide dismutase 1 (Sod1), were upregulated following Swertiamarin supplementation in 3-NPA-treated ovaries and granulosa cells. In conclusion, the present study demonstrates that Swertiamarin can partially restore defective follicular development induced by oxidative stress via modulating the NRF2/HO-1 pathway in granulosa cells. These findings provide novel insights into the potential application of Swertiamarin in enhancing female reproductive health and offer a promising strategy for addressing reproductive damage caused by oxidative stress. Full article

Background/Objectives: Puberty is a critical stage in sheep development when reproductive capability is established, but the hormonal mechanisms underlying this transition remain incompletely understood. This study aimed to investigate the dynamic changes in estradiol (E2) levels and the expression patterns of estrogen receptors (ERα and ERβ) during puberty in Duolang sheep, a breed characterized by early sexual maturity and high reproductive efficiency. Methods: A total of 18 female Duolang sheep were assigned to three developmental stages (n = 6 per group): prepuberty (145 days), puberty (within 0 h of first estrus), and postpuberty (+3 days). Serum E2 concentrations and the mRNA and protein levels of ERα and ERβ were assessed in the hypothalamus, pituitary, and ovary. Additionally, primary ovarian granulosa cells (GCs) were isolated and stimulated in vitro with increasing concentrations of E2 (0–1000 ng/mL) to evaluate the dose-dependent expression of ERα, ERβ, and gonadotropin-releasing hormone (GnRH). Results: E2 levels peaked at the onset of puberty and declined thereafter. ERα expression in the hypothalamus and pituitary decreased during puberty but rebounded postpuberty, indicating a role in negative feedback regulation. In contrast, ovarian ERα expression reached its highest level during puberty, while ERβ expression in the ovary gradually increased from prepuberty to postpuberty. In GCs, ERα exhibited a biphasic expression pattern, peaking at 250 ng/mL E2 and decreasing at higher concentrations. ERβ and GnRH expression levels increased in a dose-dependent manner. Conclusions: These findings suggest that ERα primarily mediates E2 feedback within the hypothalamus–pituitary axis, whereas ERβ is associated with ovarian development and may regulate GnRH expression during the pubertal transition. The study provides new insights into the hormonal regulation of puberty in Duolang sheep and offers potential biomarkers for improving reproductive efficiency through targeted breeding strategies. Full article

Infertility affects 17.5% of couples worldwide, and is notably caused in females by ovarian disorders that impact follicle development and oocyte maturation. Polycystic ovary syndrome (PCOS), affecting 8 to 13% of women of reproductive age, is a leading cause of anovulation and is characterized by arrested antral follicle development before the preovulatory stage. Reproductive issues of PCOS are often exacerbated in overweight or obese women. Obesity, which is increasingly prevalent worldwide, is also associated with anovulation, primarily due to defects in oocyte quality. Oocyte quality and competence depend on the proper activity of granulosa cells (GCs), which surround and support the oocyte. GCs produce key factors, such as 17β-estradiol, which regulate follicle growth and oocyte maturation. They also provide essential metabolic support for oocyte maturation and play a critical role in ovulation and fertilization. This review outlines the physiological role of GCs in follicle growth and maturation and explores recent advancements in understanding GCs’ molecular and physiological dysfunctions that contribute to infertility in PCOS and obesity. Improved knowledge of the endocrine mechanisms underlying follicular abnormalities in these conditions could help to predict oocyte competence and enhance assisted reproduction outcomes. Full article

Donkeys (Equus asinus) hold significant agricultural value in China, particularly for their hides and meat, which possess notable medicinal and dietary importance. However, their reproductive efficiency remains suboptimal compared with other livestock. Ovarian function is a key determinant of fertility, yet the molecular mechanisms underlying donkey ovarian biology remain largely unexplored. To address this gap, we performed single-cell RNA sequencing of donkey ovaries, generating a high-resolution transcriptomic atlas comprising 17,423 cells. Cross-species comparative analysis revealed a high degree of evolutionary conservation in core ovarian cell types, including endothelial, epithelial, immune, and smooth muscle cells, among vertebrates. In contrast, granulosa and theca cells exhibited distinct transcriptional profiles across species, reflecting lineage-specific adaptations. Notably, we identified key genes with donkey-specific expression patterns, including NR3C1 in endothelial cells, LIPE in granulosa cells, and DHRS9 in theca interna cells. Furthermore, an in vitro cumulus–oocyte complex model demonstrated the critical role of GATM in mammalian oocyte maturation. Collectively, these findings provide a comprehensive characterization of ovarian cell-type conservation and species-specific adaptations, offering key molecular insights into the mechanisms underlying cross-species differences in reproductive efficiency. Full article

Toll-like receptors (TLRs) play crucial roles in innate immunity, but their function in reproduction remains poorly understood. This study investigated the expression patterns and localization of TLR1-9 in the reproductive system of Hu sheep and their potential association with prolificacy. All TLRs were expressed in the oviduct, uterus, and ovary, with TLR6 showing significantly higher expression in the oviduct, while TLR3, TLR6, and TLR7 were predominantly expressed in the ovary. Following this initial screening, we focused on TLR2, TLR6, and TLR7 for detailed analysis. Immunohistochemical analysis revealed that TLR2, TLR6, and TLR7 were localized in the luminal epithelium and circular muscle of the oviduct, the luminal and superficial glandular epithelium of the uterus, and in ovarian follicles at all developmental stages. A comparative analysis between high-prolificacy (HP) and low-prolificacy (LP) Hu sheep demonstrated significantly lower TLR2 expression in the reproductive organs of HP sheep, while TLR6 expression was higher and TLR7 expression was lower in HP ovaries compared to LP ovaries. Notably, TLR7 was observed around apoptotic bodies of granulosa cells, suggesting a potential role in follicular development through the regulation of granulosa cell apoptosis. These findings establish a novel link between innate immunity and reproductive function in sheep, suggesting that TLRs, particularly TLR2, TLR6, and TLR7, may serve dual roles as immune sentinels and reproductive regulators influencing ovine fertility. Full article

Hepatitis E, caused by the hepatitis E virus (HEV), is a zoonotic disease that extends beyond hepatocellular necrosis to replicate in multiple organs. While most infections are self-limiting, HEV infection during pregnancy is associated with severe outcomes, including acute liver failure, preterm delivery, and miscarriage, with the mechanisms underlying this high pathogenicity remaining poorly understood. This study established a pregnant tree shrew model with a late-stage HEV infection and a cellular model using zoonotic HEV genotypes GT3 and GT4 to investigate the effects of estrogen on HEV replication. Results showed that negative-strand RNA detection revealed replicative intermediates in feces and tissues during the acute phase, with peak viral loads occurring within one week and the highest titers in bile. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels rose at 3 days post-inoculation (DPI), peaking at 7 DPI. Elevated estrogen levels post-miscarriage correlated with increased viral loads, a trend mirrored in cell culture models showing linear relationships between estrogen and viral replication. Histopathology demonstrated viral hepatitis lesions in liver tissues and abnormalities in the uterus, ovaries, and brain, including hydropic degeneration, neuronal disruption, and granulosa cell necrosis. This study developed a pregnant tree shrew model for HEV infection, providing a robust tool for exploring pathogenic mechanisms during pregnancy and genotype-specific differences in zoonotic HEV pathogenicity. These findings offer new insights into the role of estrogen in HEV replication and its contribution to adverse pregnancy outcomes. Full article

Background: Adult granulosa cell tumours (AGCT) of the ovary account for 2–5% of ovarian tumours, with 30% occurring in women of childbearing age. Despite a good prognosis, up to 25% recur. There is a paucity of high-quality evidence to guide management. Objective: To describe management of AGCT across multiple gynaecological cancer centres. Methods: Retrospective analysis of electronic patient records from six gynaecological cancer centres in Southwest England between 2000 and 2021 (n = 119). Results: We included 107 patients with a median follow-up of 60 months (0–261 months). Most (97/107; 90.7%) were diagnosed with stage I disease (31.8% stage Ic). Primary management was staging surgery in 33/107 (30.8%), hysterectomy and bilateral salpingo-oophorectomy (BSO) (28/107; 26.2%), or conservation of an ovary (17/107; 15.9%). Three had a subsequent pregnancy. A quarter (27/107; 25.2%) were diagnosed with recurrent disease. Fifteen patients (15/107; 14%) had multiple recurrences. Recurrence was more likely if cyst rupture was reported at surgery (38.7%) compared with no rupture (14.3%; p < 0.001). The recurrence rate was higher with ovarian conservation (6/17; 35.3%) compared with BSO (21/90; 23.3%; p < 0.01), and all recurrences involved the residual ovary. Of the 11 deaths, 6 (54.5%) were attributed to progressive disease. Conclusions: Although survival with early-stage disease is good, ovarian cystectomy or unilateral ovarian conservation was associated with increased risk of recurrence. There is no conclusive evidence to support a contralateral oophorectomy in pre-menopausal women, but completion surgery should at least be considered, either immediately or after childbearing/assisted reproductive treatment. Full article

The aim of this study is to examine the influence of food restriction on rabbit ovarian functions. A total of eight females were fed ad libitum (NF), while eight females were subjected to 50% food restriction (RF). One month later, all females were euthanized. Weights and lengths of ovaries and uterine horns were measured. Representative parts of the ovaries were subjected to histomorphometry analysis of folliculogenesis. Granulosa cells were isolated and cell viability, proliferation (accumulation of PCNA, cyclin B1, and BrdU-positive cells), apoptosis (accumulation of bax, caspase 3, and DNA fragmentation) were evaluated. Granulosa cells were subjected to proteomic analysis by using the nano HPLC-Chip-MS/MS method. Estradiol and progesterone release by ovarian and granulosa cells was assessed by ELISA. Ovarian and uterine horn weights were lower in RF than NF. The diameter of follicles and oocytes and the thickness of the theca and granulosa cells were higher in RF than NF. RF showed a lower percentage of cells containing bax and caspase 3, occurrence of DNA fragmented cells, and estradiol and progesterone. RF had higher incorporation of BrdU, a higher proportion of cells containing PCNA and cyclin B1, and a lower percentage of viable cells. RF produced more specific proteins than NF, including peptides involved in cell differentiation, proliferation/division, mitotic cell cycle, and GTP-ase activity. In conclusion, food restriction can activate reproduction by (1) selection of the growing primordial follicles, (2) better transformation of secondary to preovulatory follicles, (3) increasing growth of oocytes, (4) increasing proliferation and decreasing apoptosis in granulosa cells, (5) changes in ovarian secretory activity, and (6) changes in the number of peptides. Full article

Thyroid hormone (TH) plays a vital role in ovarian follicle development, and glucose-regulated protein 78 (GRP78) is involved in these processes, which is regulated by TH. However, the mechanisms are still unclear. To evaluate the possible mechanism of TH on the regulation of GRP78 expression, Cleavage Under Targets and Tagmentation (CUT & Tag) sequencing, luciferase assays, and Electrophoretic Mobility Shift Assays (EMSA) were employed to delineate the binding sites of thyroid hormone receptor β (TRβ) on the GRP78 promoter and to confirm the interactions. Additionally, Co-Immunoprecipitation (Co-IP) and Immunofluorescence (IF) assays were used to investigate the interactions between TRβ and the coactivator peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) after triiodothyronine (T₃) treatment with different concentrations. Our findings identified a thyroid hormone response element (TRE) on the GRP78 promoter and demonstrated that TRβ can activate GRP78 expression by interacting with PGC-1α. In order to simulate the condition of hyperthyroidism, granulosa cells (GCs) extracted from rats were treated by T₃ with high concentrations, which decreased the expression of PGC-1α, resulting in decreased expressions of GRP78 and other ferroptosis-related markers such as glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11, xCT), thereby inducing ferroptosis in GCs. Taken together, the present study demonstrates that T₃ induces cellular ferroptosis by binding TRE of the GRP78 promoter in ovarian GCs via TRβ. As a switcher, PGC-1α is also involved in these processes. Full article