Search Results (76)

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

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

Lipid accumulation disrupts mitochondrial dynamics, leading to dysfunctional energy metabolism and increased oxidative stress. However, the relationship between mitochondrial dynamics and ovarian function in therapeutic contexts is still not fully elucidated. Therefore, the objective of this study was to demonstrate whether increased carnitine palmitoyltransferase 1A (CPT1A) expression induced by placenta-derived mesenchymal stem cells (PD-MSCs) improves ovarian function in ovaries of a lipid toxicity-induced rat model by regulating lipid metabolism and mitochondrial dynamics. A rat model of injury was induced through intraperitoneal administration of thioacetamide (TAA) for 12 weeks. During the 8th week of induction, PD-MSCs (2 × 10⁶ cells) were transplanted via the tail vein. Initially, we examined the engraftment of PD-MSCs. The inflammatory response (e.g., IL-6, TNFα) and apoptosis (e.g., LDH levels, TUNEL assay) were significantly increased in the non-transplanted (NTx) group compared to the normal group; however, they were significantly decreased in the transplanted (Tx) group compared to the NTx group (* p < 0.05). Additionally, oxidative stress was attenuated through the regulation of mitochondrial dynamics, including the expression of DRP1, ATP5B, and PGC1α, in the Tx group compared to the NTx group (* p < 0.05). In the NTx group, abnormally accumulated lipid droplets were observed due to dysfunctional mitochondria, whereas in the Tx group, the accumulation of lipid droplets and the expression of CPT1A were significantly comparable to those in the normal group (* p < 0.05). The levels of the steroidogenesis markers (e.g., CYP11A1 and HSD3β1) were decreased in the NTx group compared to the normal group and increased in the Tx group compared to the NTx group (* p < 0.05). The levels of sex hormone and follicular development were protected in the Tx group compared to the NTx group. Furthermore, cocultivation of PD-MSCs with etomoxir (CPT1A inhibitor)-treated primary theca cells increased the expression of steroidogenesis. In conclusion, PD-MSCs improve ovarian function in TAA-induced injury by reducing lipid accumulation and oxidative stress through the regulation of lipid metabolism and mitochondrial dynamics. The upregulation of CPT1A and related mitochondrial proteins contributes to enhanced steroidogenesis and restoration of ovarian homeostasis. These findings offer new insights into the application of stem cell therapies for reproductive medicine. 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

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder affecting reproductive-aged women. Previous studies have identified genomic associations at chromosome 12q13.2, but the functional mechanisms underlying these associations remain unclear. We integrated three complementary datasets: (1) WES-identified single nucleotide variants (SNVs) from PCOS and normal theca cells with association testing for forskolin-stimulated androgen production, (2) STARR-seq enhancer activity data with eQTL colocalization analysis, and (3) scRNA-seq expression data comparing forskolin-stimulated PCOS and normal theca cells. We previously identified haplotypes involving 10 SNVs at 12q13.2 containing RPS26/RAB5B/SUOX that are significantly associated with forskolin-stimulated androgen production. The identified haplotypes were further shown to associate with PCOS in a whole genome sequencing (WGS) cohort. Other studies have recently found the enhancer variant rs1081975 demonstrated perfect colocalization (PP = 1.0) with RPS26/RAB5B/SUOX eQTLs. Our scRNA-seq analysis revealed differential expression patterns for key genes. RAB5B showed a forskolin response upregulation in normal cells but an impaired response in PCOS. SUOX exhibited opposite forskolin responses between normal and PCOS cells. PA2G4, an androgen corepressor in the locus, was upregulated in normal untreated cells. ERBB3, an epidermal growth factor receptor in the locus, was downregulated in normal forskolin treated cells. The integration of multimodal genomic data provides functional validation of PCOS-associated variants at 12q13.2, revealing coordinated dysregulation of vesicular trafficking (RAB5B), androgen receptor regulation (PA2G4), and metabolic processes (SUOX) in PCOS theca cells. Full article

The yak is a large ruminant that lives in the high-altitude and hypoxic environment of the Qinghai–Tibet Plateau in China and typically exhibits limited reproductive capacity, posing a significant challenge to the advancement of animal husbandry in the region. Retinoid X receptors (RXRs), as an important member of the NR superfamily, play a key role in the regulation of reproductive hormone synthesis, follicular development, and embryo implantation. However, there is still a lack of systematic research on the expression characteristics and potential functions of RXRs in the yak’s reproductive system. This study characterized RXR expression in ovarian, uterine, and oviductal tissues from three yaks per reproductive phase (follicular, luteal, and pregnancy). Using Quantitative Real-Time PCR Experiments (RT-qPCR), Western blot (WB), immunohistochemistry (IHC), and immunofluorescence (IF), we analyzed RXR mRNA and protein expression and localization. RXR expression varied significantly (p ≤ 0.05), peaking in ovaries during the follicular phase, oviducts during the luteal phase, and uteri during pregnancy. RXRs were localized in ovarian granulosa and theca cells, oviductal epithelium, and uterine endometrial glands, with dynamic nuclear–cytoplasmic shifts. These findings suggest RXRs regulate key reproductive processes in yaks, offering insights on improving fertility in high-altitude environments. Full article

This review article focuses on the role of choline in ovarian follicular development, regulated by nutrient–epigenetic interactions. Choline, a key feed additive, participates in DNA methylation and steroid hormone synthesis via its methyl donor function. However, its role in follicular hierarchy and maturation is unclear. Research lacks an understanding of species-specific choline metabolism, follicular fluid methylation dynamics, and toxicity thresholds. This study combines animal nutrition, epigenetics, and reproductive endocrinology. Using in vitro follicle culture models, metabolomics analysis, and cytochrome P450 family 19 subfamily A member 1 (CYP19a1) methylation site screening, it reveals that choline regulates follicle hierarchy through the betaine-S-adenosylmethionine (SAM) pathway. Proper dietary choline reduces homocysteine (HCY) and boosts CYP19a1 demethylation, enhancing theca cell estradiol (E₂) production and accelerating follicle maturation. In contrast, inadequate or excessive choline causes mesoderm-specific transcript (MEST) gene methylation abnormalities or trimethylamine N-oxide (TMAO)-mediated β-oxidation inhibition, increasing follicle atresia. A phenomenon of steroidogenic factor 1 (SF-1) methylation has been observed in poultry, showing that choline affects offspring egg-laying persistence by altering the adrenal–ovarian axis DNA methylation imprint. Future research should establish a precise choline supply system based on the HCY/TMAO ratio in follicular fluid and the CYP19a1 methylation map to improve animal reproduction. Full article

Background/Objectives: Platelet-derived growth factor receptor alpha (PDGFRα) is a receptor involved in cell growth and differentiation, with unclear roles in ovarian tissues and potential interactions with KCNK3 (potassium two-pore domain channel subfamily K member 3), a member of the two-pore domain K⁺ channel involved in cellular homeostasis. This study aims to map PDGFRα expression across mouse tissues and to explore its co-expression with KCNK3 in the ovary. Methods: We visualized PDGFRα expression using RNA-seq data from the genotype-tissue expression (GTEx) BodyMAP across 54 human tissues and Cap Analysis of Gene Expression (CAGE) data for various mouse tissues. In PDGFRα^EGFP mice expressing EGFP in PDGFRα⁺ cells, histological and fluorescence imaging were used to assess ovarian expression. Immunohistochemistry determined the co-localization of PDGFRα and KCNK3, and qPCR quantified their mRNA levels in the ovary, oviduct, and uterus. Results: PDGFRα showed high expression in human and mouse female reproductive tissues, particularly the ovary. In the PDGFRα^EGFP mouse model, PDGFRα was primarily found in the thecal layer and stromal cells, not in granulosa cells or oocytes. Immunohistochemistry indicated that 90.2 ± 8.7% of PDGFRα⁺ cells expressed KCNK3 in the ovarian stroma. qPCR revealed lower PDGFRα and KCNK3 expression in the ovary compared to the oviduct and uterus. Conclusions: This study shows that PDGFRα is predominantly expressed in ovarian stromal and theca cells and is highly co-localized with KCNK3, suggesting a potential role for PDGFRα⁺ cells in ionic regulation and their possible involvement in follicular development and ovarian physiology. 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

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

The ovary is a dynamic organ where mechanical forces profoundly regulate follicular development, oocyte maturation, and overall reproductive function. These forces, originating from the extracellular matrix (ECM), granulosa and theca cells, and ovarian stroma, influence cellular behavior through mechanotransduction, translating mechanical stimuli into biochemical responses. This review explores the intricate interplay between mechanical cues and ovarian biology, focusing on key mechanosensitive pathways such as Hippo signaling, the PI3K/AKT pathway, and cytoskeletal remodeling, which govern follicular dormancy, activation, and growth. Additionally, it examines how ovarian aging disrupts the mechanical microenvironment, with ECM stiffening and altered mechanotransduction contributing to a decline in ovarian reserve and reproductive potential. Emerging technologies, including 3D culture systems and organ-on-chip platforms, are highlighted for their ability to replicate the ovarian microenvironment and advance drug discovery and therapeutic interventions. By integrating mechanobiological principles, this review aims to enhance our understanding of ovarian function and provide new strategies for preserving fertility and combating infertility. Full article

Olive flounder (Paralichthys olivaceus) is a commercially important fish species in Japan, China, and the Republic of Korea. Despite numerous attempts to improve productivity, there have been no studies of in vitro germline stem cell (GSC) culture in this species. Here, olive flounder testicular and ovarian cell lines (OFT and OFO, respectively) were established and characterized. RT-PCR demonstrated that OFT and OFO expressed several gonadal somatic cell markers, including wt1 and fgf2, but lacked expression of germ cell markers, such as vasa, nanos2, and scp3. In addition, SNP analysis revealed that OFT originated from XY male P. olivaceus and OFO originated from XX female P. olivaceus. These results suggest that OFT was composed of Sertoli cells and OFO was composed of granulosa cells and theca cells. Finally, coculture of OFT or OFO with enriched male P. olivaceus GSCs isolated from the top 20% and 20–30% Percoll density gradient layers showed that GSCs were attached on both cell lines. In conclusion, we established P. olivaceus testicular and ovarian cell lines, which were expected to use for development of an in vitro GSC culture system. Full article

The dinoflagellate genus Heterocapsa includes several widely distributed and potentially toxic species associated with Harmful Algal Blooms (HABs), particularly affecting the Western Pacific Ocean. To reveal the biodiversity of Heterocapsa in Beibu Gulf, six strains were morphologically characterized using light and scanning electron microscopy, while large subunit rDNA (LSU rDNA) and internal transcribed spacer (ITS) were sequenced for phylogenetic analysis through maximum likelihood and Bayesian inferences. Two strains (BGERL169, BGERL170) were identified as Heterocapsa philippinensis ribotype I, three (BGERL171-BGERL173) as a new Heterocapsa philippinensis ribotype II, and one strain (BGERL174) as Heterocapsa pseudotriquetra. Cells of H. philippinensis were ovoid to spherical, yellowish-brown, with reticulate chloroplasts, and had a sausage-shaped nucleus positioned longitudinally along the dorsal side of the cell, and the theca was arranged in Po, cp, X, 5′, 3a, 7″, 6c, 5s, 5‴, 2⁗. Additionally, BGERL169 and BGERL171 showed no hemolytic toxicity in rabbit erythrocyte lysis assays. To the best of our knowledge, this research provides the first morphological and phylogenetic analysis of H. philippinensis, including the identification of a new ribotype, as well as the discovery of H. pseudotriquetra in Chinese waters. The findings contribute to the understanding of Heterocapsa species biogeography and toxicity in Chinese waters, offering valuable data for future HAB monitoring in Beibu Gulf. Full article

The development of chicken ovarian follicles involves two key stages of primordial follicle recruitment and follicle selection that are tightly regulated by multiple reproductive hormones and cytokines. Our previous study revealed an estrogen-stimulated increase in the phosphorylation level of serine at position 54 of lysine demethylase 1A (LSD1Ser54p) in the theca cells of chicken hierarchical ovarian follicles (Post-TCs). In this study, we further found that the upregulation of LSD1Ser54p by estrogen was performed by glycogen synthase kinase 3 beta (GSK3β) and that GSK3β promoted LSD1Ser54p levels by directly binding to the SWIRM and AOL1 domains of LSD1. Upon estrogen stimulation, the phosphorylation level of tyrosine at position 216 of GSK3β (GSK3βTyr216p) increased, which enhanced the binding between LSD1 and GSK3β. The subsequent transcriptome sequencing on chicken Post-TCs treated with estrogen and CUT&RUN sequencing against the LSD1Ser54p protein revealed that the expression of the farnesyl-diphosphate farnesyltransferase 1 (FDFT1) gene was simultaneously upregulated by estrogen, GSK3β, and LSD1Ser54p. Moreover, the overexpression of FDFT1 further promoted cholesterol biosynthesis in chicken Post-TCs. In short, the findings of this study suggest that estrogen-induced tyrosine phosphorylation at position 216 of GSK3β can upregulate the level of LSD1Ser54p, leading to the activation of FDFT1 expression and subsequently promoting cholesterol biosynthesis in chicken Post-TCs, which may in turn enhance estrogen synthesis. Full article

The aging ovary in mammals leads to the reduced production of sex hormones and a deterioration in follicle quality. The interstitial gland originates from the hypertrophy of the theca cells of atretic follicles and represents an accumulative structure of the ovary that may contribute to its aging. Here, reproductive and mature rabbit ovaries are used to determine whether the interstitial gland plays a crucial role in ovarian aging. We demonstrate that, in the mature ovary, interstitial gland cells accumulate lipid droplets and show ultrastructural characteristics of lipophagy. Furthermore, they undergo modifications and present a foamy appearance, do not express the pan-leukocyte CD-45 marker, and express CYP11A1. These cells are the first to present an increase in lipofuscin accumulation. In foamy cells, the expression of p21 remains low, PCNA expression is maintained at mature ages, and their nuclei do not show positivity for H2AX. The interstitial gland shows a significant increase in lipofuscin accumulation compared with the ovaries of younger rabbits, but lipofuscin accumulation remains constant at mature ages. Surprisingly, no accumulation of cells with DNA damage is evident, and an increase in proliferative cells is observed at the age of 36 months. We suggest that the interstitial gland initially uses lipophagy to maintain steroidogenic homeostasis and prevent cellular senescence. Full article