Search Results (638)

Women of reproductive age, especially those with polycystic ovarian syndrome (PCOS), often use glucagon-like peptide-1 receptor agonists (GLP-1RAs) to improve their metabolic functions. A growing body of evidence suggests that GLP-1R signaling may directly affect ovarian physiology, influencing granulosa cell proliferation, survival pathways, and steroidogenic production, in addition to its systemic metabolic effects. Nonetheless, there is a limited comprehension of the molecular mechanisms that regulate these activities and their correlation with menstrual function, reproductive potential, and assisted reproduction. This comprehensive review focuses on ovarian biology, granulosa cell signaling networks, steroidogenesis, and translational fertility outcomes, integrating clinical, in vivo, and in vitro information to elucidate the effects of GLP-1 receptor agonists on reproductive health. We conducted a thorough search of PubMed, Scopus, and Web of Science for randomized trials, prospective studies, animal models, and cellular experiments evaluating the effects of GLP-1RA on reproductive or ovarian outcomes, in accordance with PRISMA criteria. The retrieved data included metabolic changes, androgen levels, monthly regularity, ovarian structure, granulosa cell growth and death, FOXO1 signaling, FSH-cAMP-BMP pathway activity, and fertility or IVF results. Clinical trials shown that GLP-1 receptor agonists improve menstrual regularity, decrease body weight and central adiposity, increase sex hormone-binding globulin levels, and lower free testosterone in overweight and obese women with PCOS. Liraglutide, when combined with metformin, significantly improved IVF pregnancy rates, whereas exenatide increased natural conception rates. Mechanistic studies demonstrate that GLP-1R activation affects FOXO1 phosphorylation, hence promoting granulosa cell proliferation and anti-apoptotic processes. Incretin signaling altered steroidogenesis by reducing the levels of StAR, P450scc, and 3β-HSD, so inhibiting FSH-induced progesterone synthesis, while simultaneously enhancing BMP-Smad signaling. Animal studies demonstrated both beneficial (enhanced follicular growth, anti-apoptotic effects) and detrimental results (oxidative stress, granulosa cell death, uterine inflammation), indicating a context- and dose-dependent response. GLP-1 receptor agonists influence female reproductive biology by altering overall physiological processes and specifically impacting the ovaries via FOXO1 regulation, steroidogenic enzyme expression, and BMP-mediated FSH signaling. Preliminary clinical data indicate improved reproductive function in PCOS, as seen by increased pregnancy rates in both natural and IVF cycles; nevertheless, animal studies reveal a potential risk of ovarian and endometrial damage. These results highlight the need for controlled human research to clarify reproductive safety, molecular pathways, and optimum therapy timing, particularly in non-PCOS patients and IVF settings. Full article

The Transforming Growth Factor-β (TGF-β) superfamily comprises highly conserved cytokines that orchestrate key cellular functions, including proliferation, differentiation, and apoptosis. Within the ovary, TGF-β family members serve as pivotal regulators of folliculogenesis, exerting stage-specific actions from embryonic germ cell development to advanced follicular maturation. During fetal development, activins and SMAD-dependent signaling pathways are essential for primordial germ cell proliferation, survival, and the breakdown of germ cell cysts, enabling the establishment of the primordial follicle pool. Throughout folliculogenesis, TGF-β supports follicle activation, promotes the transition from dormant to growing follicles, stimulates granulosa cell proliferation, sustains follicular viability, and modulates steroidogenesis through theca cell regulation. Notably, anti-müllerian hormone, a TGF-β family member, plays a central role in inhibiting premature follicle recruitment and serves as a key biomarker of ovarian reserve. Dysregulation of TGF-β signaling contributes to various ovarian disorders, including polycystic ovary syndrome and premature ovarian insufficiency. A deeper understanding of these complex signaling networks is critical for identifying novel therapeutic targets and advancing clinical interventions in female reproductive pathologies. This review provides an integrated overview of the roles of the TGF-β superfamily in ovarian physiology and its contributions to disease development. Full article

Follicle-stimulating hormone receptor (FSHR) is expressed on the plasma membrane of granulosa cells in the ovarian follicles. FSHR is involved in the development and maturation of Graafian follicles, along with granulosa proliferation and estrogen synthesis. There are two well-characterized non-synonymous single-nucleotide gene polymorphisms in the exon 10 of the human FSHR gene, namely rs6165 (c.919G>A, Ala307Thr) and rs6166 (c.2039A>G, Ser680Asn). Recent research clarifies the association of rs6165/rs6166 with susceptibility to infertility-associated ovarian diseases, ranging from polycystic ovarian syndrome, premature ovarian insufficiency, endometriosis, to ovarian cancer, along with response/resistance to ovulation induction/ovarian stimulation with clomiphene citrate, letrozole, metformin, FSH preparations, and adjunctive growth hormone in infertility treatment. This narrative review aims to update the knowledge on the relationship among rs6165/rs6166, infertility etiology, and differential responses to oral ovulation induction agents, FSH preparations, and adjunctive growth hormone. The re6165/rs6166 genotype-guided choice of individualized ovulation stimulation preparations has great potential to reduce unexpected poor or high ovarian responses in ovulation induction and ovarian stimulation and improve clinical outcomes in reproductive medicine. Current evidence is insufficient, and further studies are warranted to ascertain its potential for clinical implementation. Full article

Microplastics (MPs) and nanoplastics (NPs) are widespread environmental contaminants with documented impacts on human health, particularly on the female reproductive system. Defined as polymeric fragments smaller than 5 mm, MPs (typically ranging from 1 µm to 5 mm) and NPs (smaller than 1 µm, often <100 nm) originate either from primary sources—intentionally manufactured for specific industrial applications—or from secondary sources through physical, chemical, or biological degradation of macroplastics. Human exposure occurs via multiple routes, including ingestion, inhalation, dermal absorption, and iatrogenic introduction, with growing evidence that these particles can accumulate in the ovaries, oocytes, and placental tissue. Experimental studies in rodents demonstrate that MPs and NPs induce oxidative stress, trigger inflammatory responses, and promote granulosa cell apoptosis, ultimately diminishing ovarian reserve and impairing folliculogenesis. Clinical and pilot human studies have confirmed the presence of MPs in placentas, umbilical cord blood, and meconium, indicating exposure from the earliest stages of development. Moreover, MPs and NPs may disrupt the hypothalamic–pituitary–ovarian axis, contributing to endocrine dysregulation and hormonal imbalance. Analytical methods such as Fourier-transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy enable detection of these particles in biological samples, although methodological standardization remains insufficient. This paper summarizes current evidence on the exposure pathways, toxicological effects, and reproductive consequences of MPs and NPs in women. It further highlights existing research gaps and evaluates available analytical approaches to support future studies and develop strategies aimed at mitigating their detrimental impact on women’s reproductive health and fertility. Full article

Background and Clinical Significance: Anti-Müllerian hormone (AMH) is a dimeric glycoprotein secreted from the granulosa cells of the preantral and small antral follicles, which has entered routine clinical practice as a valuable tool for the diagnosis of different ovarian disorders. Increased AMH levels have been recommended as a criterion for polycystic ovary syndrome (PCOS). However, its widespread use remains limited due to analytical diversity and contradictory age-specific thresholds, among other factors that modulate AMH levels. Case Presentation: Herein, we present a rare case series of women with increased AMH levels. The difficulties in the differential diagnosis of patients with elevated AMH levels, because of PCOS combined with pituitary dysfunction, increased ovarian volume, or granulosa cell tumors (GCTs), are discussed. Conclusions: The presented rare cases of increased AMH emphasize the important role of AMH as a diagnostic marker in women with hypogonadotropic hypogonadism and granulosa cell tumors. On the other hand, it is still unknown if increased AMH produced by unusually enlarged or supernumerary ovaries should be considered as actual PCOS cases or as a specific subgroup. Additionally, the unusual case of GCTs with pronounced AMH and LH increase but normal steroids supports the pathophysiological role of AMH for the development of neuroendocrine dysfunction. Moreover, it suggests that GCTs should be considered in the differential diagnosis of chronic anovulation even in women with normal ovarian steroid production in case of unusually high AMH levels for the age. Further studies are needed to explain PCOS heterogeneity and to ensure proper differential diagnosis for every affected woman. Full article

Dabie Mountain cattle are characterized by their ability to tolerate coarse feed, strong disease resistance, and delicious meat. Lower reproductive efficiency has become one of the key factors limiting its development. Therefore, this study investigated the developmental patterns of Dabie Mountain cattle follicles and screened key candidate genes for in vitro experimental validation. Research collected granulosa cells from small follicles (<5 mm), medium (5–8 mm), and big (>8 mm), followed by RNA extraction for transcriptomic sequencing. A total of 20,775 genes were identified, including 13,777 (66.3%) differentially expressed genes (DEGs). DEGs showing up-regulation and down-regulated in B vs. S, B vs. M, and M vs. S groups were collected. A total of 19 commonly up-regulated DEGs across the three groups were identified, including genes such as DEFB, FAM124A, and RASSF10. Additionally, 227 commonly down-regulated DEGs were identified, including genes such as INSL3, GAS7, and PAQR7. Protein interaction network analysis revealed an interaction between INSL3 and STAR. Bovine ovarian granulosa cells (GCs) were collected to investigate the effect of the INSL3 on GCs proliferation. The results revealed that INSL3 expression was highest in small follicles and was almost absent in big follicles. Subsequently, the INLS3 gene was knocked down in GCs using small interfering RNA. RT-qPCR results demonstrated that both si-INSL3 (239) and si-INSL3 (392) significantly knock down INSL3 expression (p < 0.01), si-INSL3 (239) for follow-up research. CCK-8 was used to assess cell proliferation, revealing that INSL3 knockdown significantly enhanced GCs viability and number at 24, 48, and 72 h (p < 0.05). Flow cytometry was used to detect cell cycle distribution. The results showed that knockdown of INSL3 expression significantly decreased the proportion of G1 phase cells and significantly increased the number of S phase cells (p < 0.01). RT-qPCR was used to detect the expression of cell proliferation-related genes. The results showed that compared with the siNC group, the expression levels of Myc, PCNA, Cytochrome C, and Cyclin D1 were significantly increased in the si-INSL3 group. In conclusion, knockdown of INSL3 affects follicular development in Dabie Mountain cattle by regulating granulosa cell proliferation in the ovaries, providing new insights into the regulatory mechanisms of follicular development in cattle. Full article

Ovarian interstitial tissue (IT) is a prominent but poorly characterised component of the koala ovary. This study analysed the morphology and immunohistochemical profile of IT in the koala ovary across different reproductive phases. Ovaries from ten sexually mature females were examined histologically and immunolabelled for aromatase, HSD3B2, HSD17B1, the follicle stimulating hormone receptor (FSHR), and the luteinizing hormone receptor (LHR). IT occurred as multifocal cortical aggregates composed of two distinct cell types. Large interstitial cells were polygonal with highly vacuolated and weakly eosinophilic cytoplasm and were morphologically consistent with a steroidogenic phenotype. Small interstitial cells were densely eosinophilic, non-vacuolated, and morphologically uniform across reproductive phases. Immunohistochemical analysis revealed that small interstitial cells exhibited the broadest expression of steroidogenic markers in the ovary, with coexpression of HSD3B2, HSD17B1, aromatase, FSHR, and LHR. In contrast, large interstitial cells exhibited comparatively limited enzyme and receptor expression. Staining intensity across all markers was strongest during the interoestrous phase, moderate in the proliferative phase, reduced in the luteal phase, and minimal or absent when the koalas were lactating, suggesting potential cyclical variation in IT function. Granulosa, theca and germinal epithelial cells showed variable expression of steroidogenic enzymes and gonadotropin receptors, indicating that ovarian steroidogenesis in the koala may be more heterogeneous than predicted by the classical two-cell, two-gonadotropin model. Together, these findings provide preliminary evidence for the steroidogenic capacity of ovarian IT in the koala, indicating that its activity varies across reproductive phases, and appear to suggest a unique cellular organisation compared to other mammals. As these results are based on morphology and immunohistochemistry alone, further functional studies are required to confirm the steroidogenic output and clarify the physiological significance of IT in this species. Full article

We studied fine particulate matter (PM) effects on porcine granulosa, a model of endocrine reproductive cells, and on ovarian endothelial cells. PM produced a significant decrease (p < 0.05) in metabolic activity. PM reduced endothelial cell proliferation (p < 0.001). As for redox status, superoxide anion (O₂⁻) production by granulosa was reduced (p < 0.05) by PM, while it was increased in endothelial cells (p < 0.001). PM increased (p < 0.001) nitric oxide (NO) levels in granulosa, while in endothelial cells, it displayed a biphasic effect (p < 0.05) as well as for superoxide dismutase activity (SOD) in granulosa cells (p < 0.001). In endothelial cells, PM increased (p < 0.001) SOD. A reduction in Ferric Reducing Ability of Plasma (FRAP) (p < 0.01) was observed. In granulosa, PM did not induce oxidative damage to DNA, while in endothelial cells, it determined a reduction (p < 0.05). PM significantly inhibited steroidogenesis (p < 0.05). The accumulation of autophagic vacuoles and Vascular Endothelial Growth Factor (VEGF) production was increased (p < 0.05) by PM. The data obtained likely demonstrate that PM induces critical effects on ovarian cells. Full article

Oocyte-granulosa cell complexes (OGCs) cultivation is crucial for advancing reproductive biotechnology but remains incomplete and needs further optimization. Insulin-like growth factor-I (IGF-I) regulates granulosa cell proliferation and apoptosis, and numerous studies have confirmed its role in promoting ovarian follicle development. Porcine follicular fluid (PFF) contains factors beneficial for oocyte growth, which may enhance oocyte development. To investigate whether IGF-I and PFF improve the in vitro culture efficiency of porcine OGCs, we cultured OGCs with IGF-I (0, 10, 50, 100 ng/mL) and PFF (from 3 to 6 mm follicles) at concentrations of 0, 2.5%, 5%, 10%, respectively. The results revealed that 50 and 100 ng/mL IGF-I significantly increased the antrum formation rate of OGCs (from 61.11 ± 7.35% to 88.89 ± 7.35%) and diameter growth of oocytes (from 108.77 ± 0.27 µm to 114.94 ± 0.58 and 113.29 ± 0.50 µm, respectively). However, only the 50 ng/mL group, but not the 100 ng/mL group, significantly improved the maturation rate (38.13 ± 3.77% vs. 25.00 ± 3.27%, p < 0.05) of oocytes. Additionally, 50 ng/mL IGF-I downregulated BAX (a pro-apoptotic gene) and upregulated BCL-2 (an anti-apoptotic factor) in granulosa cells, ultimately reducing apoptosis. In contrast, none of the PFF doses used in this study induced the formation of enclosed antrum-like structures in OGCs, nor did they significantly enhance their in vitro development. Our findings demonstrate that 50 ng/mL IGF-I effectively promotes the in vitro growth of porcine early antral follicle-derived OGCs by reducing apoptosis, whereas tested PFF concentrations had no beneficial effects and induced abnormal granulosa cell growth. How PFF modulates the adherent and spreading growth of granulosa cells has not been fully elucidated and requires further clarification. Full article

Ovulation and granulosa cell luteinization are induced by ovulatory signals, including luteinizing hormone (LH) and human chorionic gonadotropin (hCG). Histone modifications enable rapid, signal-responsive transcriptional reprogramming. However, the effects of LH/hCG-induced histone modification changes on the mural granulosa cells (MGCs) function remain to be fully elucidated. By mining public datasets we integrated transcriptomic and histone-modification profiles of MGCs across the ovulatory interval and tracked LH/hCG-driven gene expression at three time points (0, 4, and 12 h after-hCG). During oocyte maturation, the 4 h LH-surge constitutes a critical window for meiotic resumption, during which many genes display rapid transcriptional changes followed by a return to baseline levels. Early-response genes are enriched for cell locomotion, inflammatory responses, the activation of signaling pathways, and histone modifications. Furthermore, LH/hCG-induced transcriptome remodeling is highly correlated with dynamic gains or losses of H3K4me3 and H3K27ac. Notably, we discovered for the first time that H3K27ac marks super-enhancers (SEs) that regulate LH/hCG-induced transcriptional activation in MGCs. Finally, through complementary in vitro and in vivo pharmacological inhibition, we demonstrate that LH/hCG governs oocyte maturation and ovulation by reshaping the MGC transcriptome via H3K4me3- and H3K27ac-dependent chromatin remodeling. In summary, our study advances the understanding of how gonadotropins regulate MGC function and oocyte maturation through histone-modification-mediated transcriptional control. Full article

Background/Objectives: Increasing evidence points to hypoxia and inflammation as two major causes of compromised ovarian function. Increased oxidative stress under hypoxic conditions can damage cellular components, leading to the dysfunction and apoptosis of granulosa cells (GCs). The inflammatory response induced by hypoxia may further impair the function of the ovaries and contribute to the development of premature ovarian insufficiency (POI). In animal models of premature ovarian failure, research has demonstrated that the transplantation of mesenchymal stem cells (MSCs) can enhance reproductive outcomes, increase the number of functioning ovarian follicles, and restore estradiol production. However, the specific mechanisms underlying the observed positive results are not well understood. Methods: The present study provides a comparative analysis of how MSCs influence human GC function under inflammatory and hypoxic conditions, using three different experimental approaches: direct co-culture, indirect co-culture with transwell cell culture inserts, and treatment with MSC-derived conditioned medium (MSCcm). Results: Inflammation significantly suppressed GC estradiol secretion and increased apoptosis. MSCs increased estradiol secretion in normal and hypoxic culture conditions when co-cultured directly with GCs. Our results also showed that, under inflammation, MSCs tended to decrease GC proliferation and that hypoxia alone did not have an effect on GC estradiol secretion or proliferation. Conclusions: The study emphasizes the dual nature of MSCs, which largely determines their effects on other cell types, and the need for the condition-specific optimization of MSC therapies for ovarian regeneration. Full article

During oocyte maturation, granulosa cells (GCs) respond to fluctuating hormone levels in the ovary. The study aims to reveal metabolism and activity patterns of isolated and cultured GCs, reflecting in vivo processes. A downregulation of GARNL3 and ARRDC4 across all time points (48 h, 96 h, and 144 h) suggests reduced cell signaling and response to external stimuli, which may be related to the isolation and in vitro culturing of GCs from the complex ovarian microenvironment. The consistent elevation of LOX underscores its role in extracellular matrix (ECM) cross-linking, crucial for oocyte quality, whereas FN1 and ITGB3 highlight cellular adhesion and ECM interaction during adaptation to in vitro conditions. The study further demonstrates that ANKRD1 and SLC1A1 are upregulated over time in vitro, indicating cellular differentiation and metabolic alterations. Furthermore, proteoglycan and MAPK signaling pathways are identified as key players in cell-to-cell and cell-to-ECM interactions. GSEA revealed heightened activity in vasculature development, the TGF-β signaling pathway, cell development, and lipid response. The findings suggest that while GCs in vitro mimic in vivo processes related to ECM remodeling and oocyte development, they also exhibit a tendency towards aging. The research emphasizes that isolated GCs in vitro exhibit time-dependent activity shifts related to cellular differentiation, ECM remodeling, and lipid metabolism, which also have implications for the understanding of reproductive physiology and pathologies. Full article

Previous studies have identified oxidative stress and inflammatory responses in granulosa cells (GCs) of periparturient dairy cows. However, whether non-esterified fatty acids (NEFA)-induced endoplasmic reticulum (ER) stress is involved in GC apoptosis remains unclear. In this study, treatment with NEFA (0.9 mM, 24 h) activated the ER stress pathway. This was evidenced by increased expression of both CHOP and GRP78. Furthermore, upregulation of pro-apoptotic factors BAX and Caspase-3 and downregulation of the anti-apoptotic factor Bcl-2 were observed. Pretreatment of GCs with 4-phenylbutyric acid (4-PBA, 2.5 mM, 2 h) reversed the ER stress and apoptotic effects. This suggests that NEFA-induced apoptosis is mediated through activation of the PERK pathway of ER stress, and that 4-PBA alleviates this effect. Furthermore, targeted metabolomics revealed disruptions in lipid and hormone metabolism in GCs following NEFA treatment. Analysis revealed an increase in the levels of 26 types of fatty acids, while a decrease was detected in the levels of 3 types of fatty acids. In summary, NEFA induces ER stress and disrupts intracellular fatty acid, ultimately leading to cell apoptosis. Our findings offer valuable insights for developing strategies to regulate follicular development in dairy cows and mitigate the impacts of postpartum negative energy balance (NEB). Full article

The study of ovarian biology is hampered by the lack of in vitro models that faithfully recapitulate the physiology of granulosa cells (GCs). Primary GCs have a limited lifespan, while most immortalized lines are tumor-derived and exhibit non-physiological hormonal responses. The purpose of this study was to develop and characterize a novel immortalized GC line with a stable, physiologically relevant phenotype. We immortalized primary murine GCs from early antral follicles using lentiviral vector to introduce human telomerase reverse transcriptase (hTERT) gene to create the IMG-A1 cell line. The line was extensively characterized using molecular (qRT-PCR, Western blot), cytogenetic (karyotyping), and functional (hormone stimulation, ELISA, proliferation assays) methods to assess its phenotype and responsiveness to gonadotropins and metabolic stressors. Exhibiting a non-transformed phenotype, IMG-A1 cells retain a stable karyotype and express the follicle-stimulating hormone receptor (FSHR) but not the luteinizing hormone/chorionic gonadotropin receptor (LHCGR). Accordingly, they respond to FSH by upregulating steroidogenic genes like aromatase (Cyp19a1) but are unresponsive to LH/hCG. Furthermore, the line exhibits physiologically relevant responses to hormonal stimulation, including a strong induction of aromatase by FSH and its synergistic upregulation in a hyperandrogenic and hyperinsulinemic milieu. The IMG-A1 cell line is a unique and robust model of early antral granulosa cells, offering a valuable new tool for studying FSH-dependent folliculogenesis, cellular aspects of ovarian pathophysiology, and drug discovery. Full article

Objectives: Fibroblast growth factor 9 (FGF9), a crucial member of the FGF family, functions as an intercellular signaling molecule involved in angiogenesis, embryogenesis, and tissue repair. Our previous study demonstrated that FGF9 expression in chicken hierarchical granulosa cells (Post-GCs) is regulated by LSD1 Ser54 phosphorylation and that FGF9 promotes cell proliferation. This study aims to analyze the expression and regulation of the FGF9 gene in chicken ovarian follicles and its genetic effect on laying traits in hens. Methods: Chicken FGF9 mRNA expression patterns were examined by real-time quantitative PCR (RT-qPCR). Detection of single nucleotide polymorphisms (SNPs) was performed using PCR amplification and Sanger sequencing. Transcription activity was compared using dual-luciferase reporter assay. Results: Following follicle selection, chicken FGF9 expression significantly decreased in granulosa cells (p < 0.05) while it increased in theca cells (p < 0.05). Hormonal treatments revealed differential regulation; estradiol and FSH downregulated FGF9 in both pre-hierarchical and hierarchical granulosa cells (p < 0.05), whereas progesterone exhibited opposing effects, suppressing expression in pre-hierarchical granulosa cells (Pre-GCs) but stimulating its expression in Post-GCs (p < 0.05). In theca cells, estradiol consistently inhibited FGF9 expression (p < 0.05), while FSH only affected FGF9 expression in pre-hierarchical follicles. Six SNPs in the promoter region (g.−1965G>A, g.−2177G>A, g.−2289G>A, g.−3669A>G, g.−3770A>G, g.−3906G>A) were identified, five of which (g.−1965G>A, g.−2177G>A, g.−2289G>A, g.−3669A>G, g.−3906G>A) showed significant associations with egg production traits. Notably, alleles A (g.−2289), G (g.−3669), and A (g.−3906) enhanced the transcription activity of chicken FGF9 in Pre-GCs. Conclusions: These findings provide novel insights into the expression pattern and regulatory mechanisms of chicken FGF9 during follicular development and identify some genetic markers for egg-laying traits in chickens. Full article