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Background: Bisphenol S (BPS) is the main substitute for bisphenol A (BPA), a well-known plasticiser and endocrine disruptor. BPS disrupts ovarian function in several species. Moreover, a few studies have reported that the effects of BPS might be modulated by the metabolic status, and none have characterised the granulosa cell (GC) proteome after chronic BPS exposure., Objectives: This study aimed to decipher the mechanisms of action of chronic BPS exposure on the proteome of ewe GCs while considering the interaction between a deliberate contrasted metabolism and reproductive function., Methods: Forty ewes were split into two groups with contrasted diets: restricted (R, n = 20) and well-fed (WF, n = 20). The R and WF ewes were subdivided according to the dose of BPS administered through the diet (0-50 µg/kg/day), forming four groups: R0, R50, WF0 and WF50. After 3-month BPS daily exposure, GCs were recovered during the pre-ovulatory stage and proteins were analysed by nano-liquid chromatography coupled with tandem mass spectrometry., Results: Chronic exposure to BPS affected the GC proteome differently according to the ewe metabolic status. Fifty-nine out of 958 quantified proteins were differentially abundant between groups and are mainly involved in carbohydrate and lipid pathways. Unsupervised hierarchical clustering of differentially abundant proteins (DAPs) identified four clusters of 34, 6, 5 and 14 proteins according to the BPS exposure and diet interaction. Pairwise comparisons between groups also revealed a strong effect of BPS exposure and diet interaction. Functional analysis of DAPs highlighted that BPS upregulated β-glucuronidase (GUSB; p = 0.002), a protein especially able to deconjugate bisphenol glucuronides (BP-g). Moreover, among unexposed ewes, GUSB was detected only in well-fed ewes., Discussion: Conjugation of glucuronides inhibits the oestrogenic activity of bisphenols. Upregulation of GUSB in ewes dosed with BPS would prolong the oestrogenic effects of BPS by deconjugating BPS-g into free BPS. In addition, literature has reported an up-regulation of GUSB in people suffering from obesity. Therefore, people suffering from obesity could be subjected to prolonged and aggravated exposure to BPS. These data highlighted the deleterious effects of BPS and its interaction with metabolic status., Competing Interests: Declarations Ethical approval and consent to participate All experimental procedures were conducted in accordance with the European Directive 2010/63/EU on the protection of animals used for scientific purposes and approved by the French Ministry of Nation Education, Higher Education, Research and Innovation after ethical assessment by the local ethics committee Comité d’Ethique en Expérimentation Animale Val de Loire (CEEA VdL) and INRAE consented to use the animals in this experimental protocol (protocols registered under APAFIS numbers 13965-2018042008519239v2 and 14014-2018030717477406v2). Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

The potential of microRNAs to protect the female reproductive system from the toxic influence of oil-related environmental contaminants has not yet been examined. The aim of the present study was to examine the ability of the microRNA miR-152 to prevent the toxic effects of toluene on ovarian cells. Porcine ovarian granulosa cells transfected or not transfected with miR-152 mimics were cultured with or without toluene (0, 10 and 100 ng/ml). The expression of miR-152; cell viability; proliferation (accumulation of PCNA, cyclin B1 and BrdU); cytoplasmic/mitochondrial apoptosis (accumulation of bax and caspase 3); and release of progesterone, testosterone and estradiol were quantified via RT-qPCR, the Trypan blue exclusion test, quantitative immunocytochemistry, the BrdU assay and ELISA. The addition of toluene reduced cell viability, decreased the levels of all the measured markers of proliferation and the release of all the measured steroid hormones, and promoted the expression of apoptosis markers. Transfection of cells with miR-152 mimics increased the expression of miR-152, cell proliferation, and progesterone release but reduced apoptosis and the release of testosterone and estradiol. Moreover, miR-152 prevented or inhibited all the toluene effects in addition to its inhibitory effect on testosterone and estradiol release. The present results demonstrate that miR-152 can protect ovarian cells from the harmful influence of toluene.

Acrolein is a widespread contaminant found in both diet and environment, entering the human body through food, alcohol, smoking, and exposure to fuel combustion fumes. While prior studies have highlighted acrolein's harmful impact on oocyte quality and early embryonic development in vitro, the specific mechanisms by which acrolein affects the female reproductive system in vivo remain poorly understood. This study first confirmed that in vitro acrolein exposure disrupts spindle morphology and chromosome alignment during the mid-MI stage of oocyte development, thus hindering oocyte maturation. Besides, exposure to acrolein not only stunts growth in mice but also impairs ovarian development, decreases the ovarian coefficient, disrupts follicular development, and increases the count of atretic follicles in vivo. Additional research has shown that acrolein exposure reduces the activity of key enzymes in glycolysis, pyruvate metabolism, and the tricarboxylic acid cycle within the ovaries. It also suppresses mitochondrial complex expression and disturbs the balance between mitochondrial fission and fusion, as confirmed by metabolomic analyses. Moreover, acrolein exposure in vivo induced granulosa cell apoptosis and reduced oocyte number. In summary, acrolein exposure impairs glucose metabolism and induces mitochondrial dysfunction in the ovaries., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Estrogen and estrogen receptors (ERα and ERβ) regulate a multitude of complicated physiological and pathological processes. Jan-Ake Gustafsson's group discovered ERβ in 1996, this crucial finding gives us new insights into the understanding of estrogen signaling. ERβ is highly expressed in the ovary and particularly exists in granulosa cells (GCs). ERβ is a key transcription factor in the maintenance of ovarian granulosa cell growth, differentiation, and homeostasis, and the ovulation function of ovarian follicles and oocytes. Additionally, ERβ can modulate the steroidogenic transcriptional program through phosphorylation and regulate both gonadotropin response and FOXL2 expression within the ovary. In this review, we focus on the role of ERβ in regulating ovarian granulosa cell development and homeostasis, particularly its significance in ovarian cancer (OC), premature ovarian failure (POF), and polycystic ovary syndrome (PCOS). It also highlights the prospects of small molecule compounds targeting ERβ, providing a new strategy for the treatment of ovarian-related diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective: Premature ovarian insufficiency (POI) is a disease with medical, psychological and reproductive implications, but its common therapies have limited efficacy and a likelihood of complications. This study delves into the therapeutic role of human umbilical cord mesenchymal stem cell-derived extracellular vesicles (hUC-MSCs-EVs) in POI mice through the insulin-like growth factor 1 (IGF-1)/nuclear factor E2 related factor 2 (Nrf2)/heme oxygenase-1 (HO-1)/autophagy pathway., Methods: hUC-MSCs were transfected with lentiviral short hairpin RNA of IGF-1 before EV extraction. Cyclophosphamide (CTX)-induced POI mouse models were administrated with hUC-MSCs-EVs. Mouse ovarian granulosa cells (GCs) were induced with CTX, then treated with hUC-MSCs-EVs and ML385. Ovarian histopathological changes were observed, changes in follicle number at all levels were counted and serum sex hormones were evaluated, as well as LC3II/I and Beclin-1 expression. GCs were subject to detection of proliferation, deaths, oxidative stress, and Nrf2 nuclear translocation., Results: After CTX exposure, mice showed thinner GCs layer in the ovary, reduced number of GCs and follicles at all levels, disturbed serum sex hormones, enhanced oxidative stress and autophagy, and downregulated ovarian IGF-1; whereas, hUC-MSCs-EVs upregulated IGF-1 to improve the ovarian function. hUC-MSCs-EVs carrying IGF-1 activated Nrf2/HO-1 signaling to inhibit CTX-induced excessive autophagy of GCs, but this ameliorative effect was partially weakened by inhibiting Nrf2/HO-1 signaling. hUC-MSCs-EVs inhibited excessive autophagy of GCs and improved ovarian function of CTX-induced mice through IGF-1/Nrf2/HO-1 pathway., Conclusion: hUC-MSCs-EVs activate the Nrf2/HO-1 signaling by carrying IGF-1, which in turn inhibits excessive autophagy and damage of GCs, thus improving ovarian function in POI mice., Competing Interests: Declarations Ethics approval and consent to participate All experiments were carried out after the review and approval from the ethics committee of Changzhi Medical College and conformed to internationally recognized animal research guidelines and ethics norms [Approval No. (2021)043]. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Background: Polycystic ovary syndrome (PCOS) is highly prevalent in women of reproductive age worldwide, exhibits highly heterogeneous clinical presentation and biochemical parameters, and has no cure. This study aimed to investigate the role of miR-34a-5p in PCOS, its effect on glycolysis in granulosa cells (GCs), and its potential contribution to follicular dysregulation., Methods: Herein, Follicular follicular fluid (FF) samples were collected from six patients with PCOS and six healthy controls undergoing in vitro fertilization-embryo transfer. The isolated extracellular vesicles were characterized by transmission electron microscopy, nanoparticle tracking analysis, and western blotting. Additionally, miRNA sequencing was performed to identify differentially expressed microRNAs, and their functions were analyzed through transcriptomics. The In vitro effects of miR-34a-5p on glycolysis, cell proliferation, and apoptosis were assessed in human ovarian granulosa tumour cell line (KGN cells). Targets of miR-34a-5p were identified by dual-luciferase reporter assays, and quantitative real-time polymerase chain reaction and western blotting were performed to determine gene and protein expression., Results: The level of miR-34a-5p in FF-derived extracellular vesicles derived from patients with PCOS was significantly higher than that of the control group. Transcriptomic analysis highlighted miR-34a-5p as a key regulator of glycolysis and apoptosis. Furthermore, in vitro analysis showed that miR-34a-5p targeted lactate dehydrogenase A (LDHA), inhibited glycolysis, reduced energy supply to GCs, and promoted apoptosis of KGN cells. Conversely, miR-34a-5p inhibition restored glycolysis function and cell viability., Conclusion: The findings of this study show that miR-34a-5p mediates GC apoptosis in PCOS by targeting LDHA and inhibiting glycolysis, suggesting its crucial role in PCOS pathophysiology, and offering potential therapeutic targets for improving follicular development and fertility outcomes in patients with PCOS. Further research is needed to explore the clinical implications of miR-34a-5p and its use as a biomarker for early diagnosis and prognosis of PCOS., Competing Interests: Declarations Ethics approval and consent to participate Ethical approval was provided by the Clinical Ethics Review Committee of Affiliated Hospital of Guilin Medical College (No.GZR202152). All methods were performed in accordance with the relevant guidelines and the standardized methods section. All participants signed an informed consent form. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Maternal germ plasm determines the germline in birds. Previously, we proposed the chicken-specific Bucky ball (cBuc) as a functional equivalent of the zebrafish germ plasm organizer. This study demonstrated the maternal cBuc synthesis, and verified a highly dynamic distribution of Bucky ball from oocyte nests to maturing follicles using specific antibodies. The dynamic re-localization of cBuc from the ovarian stroma to the granulosa cells, and the Balbiani structure of the oocyte was revealed. Following the accumulation of cBuc in the Balbiani body, an increased signal of chicken vasa homolog (CVH) in close contact to cBuc could be detected. Highest transcription of cBuc was recorded in follicles with diameters up to 500 µm. First RNA-interference experiments in an in-vivo follicle culture assay revealed inhibiting effects on cBuc in small follicles. These data demonstrate the maternal origin of cBuc, and underpin its role as germ plasm organizer., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Prior studies showed that mice deficient in the modifier subunit of glutamate cysteine ligase (Gclm), the rate-limiting enzyme in synthesis of the thiol antioxidant glutathione, have decreased ovarian glutathione concentrations, chronic ovarian oxidative stress, poor oocyte quality resulting in early preimplantation embryonic mortality and decreased litter size, and accelerated age-related decline in ovarian follicle numbers. Global deficiency of the catalytic subunit of this enzyme, Gclc, is embryonic lethal. We tested the hypothesis that granulosa cell- or oocyte-specific deletion of Gclc recapitulates the female reproductive phenotype of global Gclm deficiency. We deleted Gclc in granulosa cells or oocytes of growing follicles using Gclc floxed transgenic mice paired with Amhr2-Cre or Zp3-Cre alleles, respectively. We discovered that granulosa cell-specific deletion of Gclc in Amhr2Cre;Gclc(f/-) mice recapitulates the decreased litter size observed in Gclm-/- mice but does not recapitulate the accelerated age-related decline in ovarian follicles observed in Gclm-/- mice. In addition to having lower glutathione concentrations in granulosa cells, Amhr2Cre;Gclc(f/-) mice also had decreased glutathione concentrations in oocytes. By contrast, oocyte-specific deletion of Gclc in Zp3Cre;Gclc(f/-) mice did not affect litter size or accelerate the age-related decline in follicle numbers, and these mice did not have decreased oocyte glutathione concentrations, consistent with transport of glutathione between cells via gap junctions. The results suggest that glutathione deficiency at earlier stages of follicle development may be required to generate the accelerated follicle depletion phenotype observed in global Gclm null mice., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Biosynthesis of 17β-estradiol (E2) is a crucial ovarian function in mammals, which is essential for follicular development and pregnancy outcome. Exploring the epigenetic regulation of E2 synthesis is beneficial for maintaining ovary health and the optimal reproductive traits. NORFA is the first validated sow fertility-associated long non-coding RNA (lncRNA). However, its role on steroidogenesis is elusive. The aim of this study is to investigate the regulation and underlying mechanism of NORFA to E2 synthesis in sow granulosa cells (GCs)., Results: Through Pearson correlation analysis and comparative detection, we found that NORFA expression was positively correlated with the levels of pregnenolone (PREG) and E2 in follicles, which also exhibited similar alteration patterns during follicular atresia. ELISA was conducted and indicated for the first time that NORFA induced the synthesis of PREG and E2 in sow GCs in a dose- and time-dependent manner. RNA-seq, GSEA and quantitative analyses results validated that CYP11A1, the coding gene of P450SCC which is the first step rate-limiting enzyme of E2 synthesis, was a positive functional target of NORFA. Mechanistically, NORFA promotes SF-1 expression by stabilizing NR5A1 mRNA through directly interacting with its 3'-UTR, and also tethers SF-1 to shuttle into nucleus. Additionally, SF-1 in the nucleus activates CYP11A1 transcription by directly binding to its promoter, which ultimately induces E2 synthesis and inhibits GC apoptosis., Conclusion: Our findings highlight that NORFA, a multifunctional lncRNA, induces E2 synthesis and inhibits GC apoptosis through the SF-1/CYP11A1 axis in a ceRNA-independent manner, which provide valuable clues and potential targets for follicular atresia inhibition and female fertility improvement., Competing Interests: Declarations Ethics approval and consent to participate All the animal-involved experiments in this study were conducted in accordance with the Chinese guidelines for administration of affairs concerning experimental animals and were reviewed, approved, and supervised by the Institutional Animal Ethics Committee of Nanjing Agricultural University (NJAU.No20220324059). Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Background: Advanced maternal age is associated with decreased oocyte quantity and quality and in vitro fertilization (IVF) success rates. This study aimed to investigate whether melatonin supplementation can improve IVF outcomes in women of advanced maternal age by modulating cuproptosis and ferroptosis., Methods: This prospective cohort study included 161 women aged 35-45 years undergoing IVF-frozen embryo transfer cycles. Participants were assigned to either melatonin (n = 86, 2 mg daily for ≥ 8 weeks) or control (n = 75) groups. Cumulus cells were analyzed for cuproptosis and ferroptosis-related gene expression. Additional experiments were conducted on the HGL5 human granulosa cell line to assess mitochondrial function and metabolic reprogramming., Results: Melatonin supplementation significantly improved IVF outcomes in women aged ≥ 38 years, increasing clinical pregnancy rates (46.0% vs. 20.3%, P < 0.01), ongoing pregnancy rates (36.5% vs. 15.3%, P < 0.01), and live birth rates (33.3% vs. 15.3%, P < 0.05). In cumulus cells from patients, gene expression analysis revealed that melatonin modulated cuproptosis and ferroptosis-related genes, including ATP7B and GPX4, with more pronounced effects in the ≥ 38 years group. This suggests melatonin enhances cellular resilience against oxidative stress and metal-induced toxicity in the ovarian microenvironment. In vitro studies using HGL5 cells showed melatonin reduced oxidative stress markers, improved mitochondrial function, restored expression of glycolysis and TCA cycle-related genes and modulated cuproptosis and ferroptosis-related gene expression. These findings provide mechanistic insight into melatonin's protective effects against regulated cell death in ovarian cells, potentially explaining the improved IVF outcomes observed., Conclusions: Melatonin supplementation significantly improved IVF outcomes in women of advanced maternal age, particularly those ≥ 38 years old, likely by modulating cuproptosis and ferroptosis and enhancing mitochondrial function in cumulus and granulosa cells. These results suggest that melatonin could be a promising adjuvant therapy for improving IVF success rates in older women., (© 2024. The Author(s).)

Particulate matter 2.5 (PM2.5) pollution has emerged as a major global public health concern because of its adverse effects on human health. Our group has previously demonstrated that PM2.5 exposure can seriously impair ovarian function. However, the underlying mechanisms remain a mystery. This study verifies ovarian damage in mice, evidenced by inflammatory cell infiltration and follicular atresia, following 5 months of PM2.5 exposure via tracheal drip (35 µg/m³ for low dose and 150 µg/m³ for high dose). In addition, PM2.5 exposure inhibited the cell viability of human granulosa cells (KGN) and induced apoptosis at the concentrations of 50, 100, and 150 µg/mL for 24 h. The apoptosis of KGN cells induced by inflammation contributes to follicular atresia. Furthermore, we conducted RNA-sequencing analysis to identify the genes and pathways triggered by PM2.5 (100 µg/mL) exposure, which decreases the KGN cell viability. We found a significant increase in Activating Transcription Factor 3 (ATF3). Further mechanistic studies reveal a strong association between PM2.5-induced apoptosis, inflammation, and ATF3 with its downstream oxidative stress signals. In summary, the ATF3 pathway serves a vital role in the ovarian injury caused by PM2.5 exposures., (© 2024. The Author(s).)

With increasing age, the reproductive performance of women and female animals declines. However, the molecular mechanisms underlying ovarian aging and age-related fertility decline remain unclear. Granulosa cells (GCs) are suspected to play an important role in reproductive aging, and their proliferation, apoptosis, and steroid hormone secretion are used to determine the fate of follicles and ovarian function. First, we found that the proliferative ability of GCs from the old mouse group (10-month-old) decreased compared with that from the young mouse group (6-week-old), and cell cycle arrest occurred in old mice. To investigate changes in protein modification, we compared the levels of protein acetylation in GCs from young and old mice. We found that the K1118, K1120, K1122, and K1124 sites of DNA methyltransferase 1 (DNMT1) were increasingly acetylated with age, resulting in a decrease in DNMT1 protein expression. Therefore, we performed whole-genome methylation sequencing of GCs in the two groups and found that the CG methylation levels in the old group were lower than those in the young group. Furthermore, the inhibition of DNMT1 expression in GCs resulted in cell cycle arrest. This study revealed the dynamics and importance of protein acetylation and DNA methylation in GCs during reproductive aging. The findings provide a theoretical basis for studying the mechanism of reproductive aging in mammals., (© 2024. The Author(s).)

Sleep deprivation (SD) is observed to adversely affect the reproductive health of women. However, its precise physiological mechanisms remain largely elusive. In this study, using a mouse model of SD, it is demonstrated that SD induces the depletion of ovarian primordial follicles, a phenomenon not attributed to immune-mediated attacks or sympathetic nervous system activation. Rather, the excessive secretion of stress hormones, namely norepinephrine (NE) and epinephrine (E), by overactive adrenal glands, has emerged as a key mediator. The communication pathway mediated by the KIT ligand (KITL)-KIT between granulosa cells and oocytes plays a pivotal role in primordial follicle activation. SD heightened the levels of NE/E that stimulates the activation of the KITL-KIT/PI3K and mTOR signaling cascade in an β2 adrenergic receptor (ADRB2)-dependent manner, thereby promoting primordial follicle activation and consequent primordial follicle loss in vivo. In vitro experiments further corroborate these observations, revealing that ADRB2 upregulates KITL expression in granulosa cells via the activation of the downstream cAMP/PKA pathway. Together, these results reveal the significant involvement of ADRB2 signaling in the depletion of ovarian primordial follicles under sleep-deprived conditions. Additionally, ADRB2 antagonists are proposed for the treatment or prevention of excessive activation of primordial follicles induced by SD., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

The development and maturation of follicles are intricately linked to egg production and reproductive performance of chickens. Granulosa cells death directly affects the development and maturation of follicles, thereby impacting the reproductive performance of hens. Ferroptosis is a new type of cell death, it is unknown how it affects the growth and development of chicken follicles. In this study, RNA-seq analysis revealed significant differences in the expression of ferroptosis-related genes between normal follicles and atretic follicles, suggesting a potential role for ferroptosis in follicle growth and development. In addition, we found that ubiquitin-specific protease 13 (USP13) was significantly upregulated in atrophic follicles. Overexpression of USP13 results in depletion of glutathione (GSH), peroxidation of lipids, accumulation of iron, and activation of ferroptosis in chicken granulosa cells. In contrast, USP13 knockdown significantly inhibited ferroptosis events. Mechanistically, USP13 prevents the degradation of autophagy related 7 (ATG7) by deubiquitinating it, thereby enhancing the stability of ATG7 protein and ultimately promoting ferroptosis. In conclusion, this study elucidates the crucial role of the USP13-ATG7 axis in regulating ferroptosis in chicken follicle granulosa cells, thereby presenting a novel avenue for molecular breeding research in chickens., Competing Interests: DISCLOSURES The authors declare no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Glyphosate-based herbicides (GBH) are the most extensively used herbicides worldwide. Despite a presumed nondangerousness for animals, several studies reported negative effects after a GBH exposure in several animal models including birds, notably on reproductive functions. Several studies concerning the advantages of Vitamin E (VE) for antioxidant activity but also growth and reproduction have been reported in birds. However, it remains unclear whether VE could alleviate the negative effect of GBHs on chicken ovarian cells. Here we exposed chicken primary granulosa cells (GCs) from F1 and F3/4 follicles to growing doses of GBH (0.036, 0.36, 3.6, and 36 gly eq/L), with or without VE supplementation (1 mg/L) and investigated cell viability, proliferation, oxidative stress and steroidogenesis. GBH exposure did not affect F1 and F3 GCs viability but it increased cell proliferation only in F1 GCs and this effect was not altered by VE. In both F1 and F3/4 GCs, GBH exposure increased total oxidant status (TOS), reduced total antioxidant status (TAS) and consequently increased index of oxidative stress (OSI) in dose dependent manner. This latter effect for GBH 36 mg eq gly/L was totally abolished in response to VE. In both F1 and F3/4 GCs, GBH exposure reduced progesterone secretion in a dose dependent manner and this effect with GBH 0.36 and 1.8 mg eq glyphosate/L was alleviated by VE. However, we did not observe any effect of GBH and VE on the gene expression of several components of the steroidogenesis process. Taken together, these results show that GBH may have endocrine disruptor effects, and that these effects might be alleviated by antioxidant VE supplementation., Competing Interests: DISCLOSURES The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The in-depth mechanisms of microRNA regulation of premature ovarian failure (POF) remain unclear. Crispr-cas9 technology was used to construct transgenic mice. The qPCR and Western blot was used to detect the expression level of genes. H&E staining were used to detect ovarian pathological phenotypes. We found that the expression levels of microRNA-3061 were significantly higher in ovarian granulosa cells (OGCs) of POF mouse models than in controls. The miR-3061 +/- /AMH-Cre +/- transgenic mice manifested symptoms of POF. RNA-Seq and luciferase reporter assay confirmed that the PAX7 was one of the target genes negatively regulated by microRNA-3061 (miR-3061-5p). Moreover, PAX7 mediated the expression of non-canonical Wnt/Ca 2+ signalling pathway by binding to the motifs of promoters to stimulate the transcriptional activation of Wnt5a and CamK2a. In contrast, specific knock-in of microRNA-3061 in OGCs significantly downregulated the expression levels of PAX7 and inhibited the expression of downstream Wnt/Ca 2+ signalling pathway. We also discerned a correlation between the expression levels of mRNAs of the Wnt/Ca2+ signalling pathway and the levels of E2 and FSH in POF patients by examining gene expression in the follicular fluid-derived exosomes of women. We confirmed that overexpression of microRNA-3061 induced proliferative inhibition of OGCs and ultimately induced POF in mice by suppressing the transcription factor PAX7 and downregulating expression levels of its downstream Wnt/Ca 2+ signalling pathway genes., (© 2024 The Author(s). Cell Proliferation published by Beijing Institute for Stem Cell and Regenerative Medicine and John Wiley & Sons Ltd.)

The development of ovarian follicles in poultry is a key factor affecting the performance of egg production. Ovarian follicle development is regulated via the Wnt/β-catenin signaling pathway, and β-catenin, encoded by CTNNB1, is a core component of this pathway. In this study, using ovary GCs from laying hens, we investigated the regulatory role of CTNNB1 in steroid synthesis. We found that CTNNB1 significantly regulates the expression of StAR and CYP11A1 (key genes related to progesterone synthesis) and the secretion of progesterone (P4). Furthermore, simultaneous overexpression of CTNNB1 and SF1 resulted in significantly higher levels of CYP11A1 and secretion of P4 than in cells overexpressing CTNNB1 or SF1 alone. We also found that in GCs overexpressing SF1 , levels of CYP11A1 and secreted P4 were significantly greater than in controls. Silencing of CYP11A1 resulted in the inhibition of P4 secretion while overexpression of SF1 in CYP11A1- silenced cells restored P4 secretion to normal levels. Together, these results indicate that synergistic cooperation between the β-catenin and SF1 regulates progesterone synthesis in laying hen ovarian hierarchical granulosa cells to promote CYP11A1 expression.

At various stages of ovarian follicular development, more than 99% of follicles will be eliminated through a degenerative process called atresia. The regulatory mechanisms of atresia have been elucidated to some extent, involving hormones, growth factors, cytokines, and other factors. However, the stimuli initiating atresia in follicular granulosa cells remain unknown. In this study, we isolated the granulosa cells from porcine ovarian follicles (3-5 mm diameter) divided into healthy follicles (HFs) and early atretic follicles (EAFs). We applied high-throughput RNA sequencing to identify and compare differentially expressed genes (DEGs) between HFs and EAFs. A total of 31,694 genes were detected, of which 21,806 were co-expressed in six samples, and 243 genes ( p  < 0.05; FDR < 0.05) were differentially expressed (DEGs), including 123 downregulated and 120 upregulated in EAFs. GO analysis highlighted hormone metabolism, plasma membrane localization, and transporter activity. The pathway analysis indicated that 51 DEGs, involved in steroidogenesis, cell adhesion molecules, and TGF-beta signaling pathways, were highly related to atresia. Additionally, the interaction network of DEGs ( p  < 0.01; FDR < 0.05) using STRING highlighted LHR, ACACB, and CXCR4 as central nodes. In summary, this transcriptome analysis enriched our knowledge of the shifted mechanisms in granulosa cells during early atresia and provided novel perspectives into the atresia initiation.

In goats, most follicles in the ovaries will be atresia and only a few dominant follicles (DFs) may eventually mature and ovulate at a follicular wave. To investigate the potential microRNAs (miRNAs) that regulate the expression of genes associated with follicular dominance or atresia, small RNA sequencing was performed on granulosa cells of DF and subordinate follicle at the first follicular wave in goats. A total of 108 differentially expressed miRNAs were detected in the two types of follicle granulosa cells: 16 upregulated miRNAs and 92 downregulated miRNAs. Kyoto Encyclopedia of Genes and Genomes analysis of the target genes showed that TKTL1 , LOC102187810 , LOC102184409 and ALDOA are closely associated with follicle dominance and are involved in the pentose phosphate pathway. Furthermore, a coexpression network of miRNAs and follicular dominance-related genes was constructed. The qPCR results well correlated with the small RNA sequencing data. Our findings provide new insight for exploring the molecular mechanism of miRNAs in regulating follicular development in goats.

Several clinical trials have been conducted to evaluate the use of flavopiridol (FP) to treat a variety of cancers, and almost all cancer drugs were found to be associated with toxicity and side effects. It is not clear whether the use of FP will affect the female reproductive system. Granulosa cells, as the important cells that constitute the follicle, play a crucial role in determining the reproductive ability of females. In this study, we investigated whether different concentrations of FP have a toxic effect on the growth of immortalized human ovarian granulosa cells. The results showed that FP had an inhibitory effect on cell proliferation at a level of nanomole concentration. FP reduced cell proliferation and induced apoptosis by inducing mitochondrial dysfunction and oxidative stress, as well as increasing BAX/BCL2 and pCDK1 levels. These results suggest that toxicity to the reproductive system should be considered when FP is used in clinical applications., (© 2024. The Author(s).)

The timing of puberty significantly influences subsequent reproductive performance in cattle. N6-methyladenosine (m6A) is a key epigenetic modification involved in the regulation of pubertal onset. However, limited research has investigated alterations in m6A methylation within the hypothalamic-pituitary-ovarian (HPO) axis during the onset of puberty. In this study, combined analysis of methylated RNA immunoprecipitation sequencing (MeRIP-Seq) and RNA sequencing (RNA-seq) is used to describe the overall modification pattern of m6A in the HPO axis, while GSEA, KEGG, and GO analyses are used to describe the enrichment pathways of differentially expressed genes and differentially methylated genes. The m6A modifications of the differential genes KL, IGSF10, PAPPA2, and BMP15 and the pathways of cell adhesion molecules (CAMs), TGF-β, cell cycle, and steroid hormone synthesis may play roles in regulating the function of the HPO axis tissue during pubertal transition. Notably, BMP15's m6A modification depends on the action of the demethylase ALKBH5, which is recognized by the reader protein YTHDF2, promoting bovine granulosa cell proliferation, steroid production, and estrogen secretion. This study reveals for the first time the modification mechanism of BMP15 m6A during the initiation of bovine puberty, which will provide useful information for improving the reproductive efficiency of Chinese beef cattle.

Background: There are many gaps in our understanding of the mechanisms involved in ovarian follicular development in cattle, particularly regarding follicular deviation, acquisition of ovulatory capacity, and preovulatory changes. Molecular evaluations of ovarian follicular cells during follicular development in cattle, especially serial transcriptomic analyses across key growth phases, have not been reported. This study aims to address this gap by analyzing gene expression using RNA-seq in granulosa and antral cells recovered from ovarian follicular fluid during critical phases of ovarian follicular development in Holstein cows., Results: Integrated analysis of gene ontology (GO), gene set enrichment (GSEA), protein-protein interaction (PPI), and gene topology identified that differentially expressed genes (DEGs) in the largest ovarian follicles at deviation (Dev) were primarily involved in FSH-negative feedback, steroidogenesis, cell proliferation, apoptosis, and the prevention of early follicle rupture. In contrast, DEGs in the second largest follicles (DevF2) were mainly related to loss of cell viability, apoptosis, and immune cell invasion. In the dominant (PostDev) and preovulatory (PreOv) follicles, DEGs were associated with vascular changes and inflammatory responses., Conclusions: The transcriptome of ovarian follicular fluid cells had a predominance of granulosa cells in the dominant follicle at deviation, with upregulation of genes involved in cell viability, steroidogenesis, and apoptosis prevention, whereas in the non-selected follicle there was upregulation of cell death-related transcripts. Immune cell transcripts increased significantly after deviation, particularly in preovulatory follicles, indicating strong intrafollicular chemotactic activity. We inferred that immune cell invasion occurred despite an intact basal lamina, contributing to follicular maturation., (© 2024. The Author(s).)

Background: Buffalo is a globally important livestock species, but its reproductive performance is relatively low than cattles. At present, dominant follicle development specific process and mechanistic role of follicular growth related genes in water buffaloes are not well understood. Therefore, we comprehensively performed transcriptomics of granulosa cells and oocytes from different-sized follicles in water buffalo to identify key candidate genes that influence follicle development and diameter, and further explored the potential regulatory mechanisms of granulosa cells and oocytes in the process of water buffalo follicle development., Results: In this study, we found918 granulosa cell transcripts and 1401 oocyte transcripts were correlated in follicles of different diameters, and the expression differences were significant. Subsequent enrichment analysis of the co-expressed differentially expressed transcripts identified several genes targeted by long non-coding RNAs (lncRNAs) and associated with follicular development. Notably, the upregulation of BUB1 regulated by MSTRG.41325.4 and interactive action of SMAD2 and SMAD7 might have key regulatory role in follicular development. Additionally, we also detected key differentially expressed genes that potentially influence follicular hormone metabolism and growth, like ID2, CHRD, TGIF2 and MAD2L1, and constructed an interaction network between lncRNA transcripts and mRNAs., Conclusions: In summary, this study preliminarily revealed the differences in gene expression patterns among buffalo follicles of different sizes and their potential molecular regulatory mechanisms. It provides a new perspective for exploring the mechanism of buffalo follicular dominance and improving buffalo reproductive performance., (© 2024. The Author(s).)

Polycystic ovary syndrome (PCOS) is one of the most complicated chronic inflammatory diseases in women of reproductive age and is one of the primary factors responsible for infertility. There is substantial dispute relating to the pathophysiology of PCOS. Consequently, there is a critical need for further research to identify the factors underlying the pathophysiology of PCOS. Three transcriptome profiles of granulosa cells from patients with PCOS and normal controls were obtained from the gene expression integration database. We also obtained relevant microarrays of granulocytes prepared from PCOS patients and normal controls from the gene expression integration database. Then, we used the R package to perform correlations and identify differences between PCOS and normal controls with regard to immune infiltrating cells and functionality. Subsequently, intersecting genes were identified and risk models were constructed. Finally, the results were validated by enzyme linked immunosorbent assay and real-time PCR. We identified 8 genes related to cuproptosis (SLC31A1, PDHB, PDHA1, DLST, DLD, DLAT, DBT, and ATP7A) and 5 genes related to m7G (SNUPN, NUDT16, GEMIN5, DCPS, and EIF4E3) that were associated with immune infiltration. Furthermore, the expression levels of DLAT (P = .049) and NUDT16 (P = .024) differed significantly between the PCOS patients and normal controls, as revealed by multifactorial analysis. Both DLAT and NUDT16 were negatively correlated with immune cell expression and function and expression levels were significantly lower in the PCOS group. Finally, real-time PCR and enzyme linked immunosorbent assay demonstrated that the expression levels of DLAT and NUDT16 were significantly reduced in the granulosa cells of PCOS patients. In conclusion, our findings shed fresh light on the roles of immune infiltration, cuproptosis, and m7G alternations in PCOS. We also provide a reliable biomarker for the pathological classification of PCOS patients., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Patients with Polycystic ovary syndrome (PCOS) have chronic low-grade ovarian inflammation. Inflammation can cause telomere dysfunction, and telomere and telomerase complex are also involved in regulating inflammation. However, the specific mechanisms of inflammatory signaling feedback and telomere-telomerase mutual regulation remain to be discovered. This study elucidates the role of Nuclear factor kappa-B (NF-κB)-Telomerase reverse transcriptase (TERT) feedback in PCOS granulosa cell apoptosis. Using letrozole and a high-fat diet, a PCOS rat model was established, along with a Lipopolysaccharide (LPS) -treated KGN cell inflammation model was established. NF-κB and TERT inhibitors (BAY 11-7082 and BIBR1532) were then administered to LPS-induced KGN cells. PCOS rats displayed disrupted estrous cycles, increased weight, elevated serum testosterone, cystic follicles, granulosa cell layer thinning, and reduced corpora lutea count (P are all less than 0.05). In PCOS rat ovaries, NF-κB, Interleukin-6 (IL-6), Tumor Necrosis Factor α (TNF-α), TERT, Bax, and Caspase-3 exhibited notable upregulation, while Bcl-2 decreased, with telomere elongation (P are all less than 0.05). There were significant correlations among NF-κB-related inflammatory factors, TERT and apoptotic factors, and they were positively correlated with Bax and Caspase-3, and negatively correlated with Bcl-2 (P are all less than 0.05). LPS-treated KGN cells demonstrated increased expression of inflammatory and pro-apoptotic factors, later restored post-treatment with NF-κB and TERT inhibitors (P are all less than 0.05). In conclusion, TERT may induce granulosa cell apoptosis by participating in the regulation of the NF-κB signaling pathway, thereby mediating the chronic inflammatory response of PCOS through downstream inflammatory factors IL-6 and TNF-α., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Xue et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Primordial follicle activation (PFA) is a pivotal event in female reproductive biology, coordinating the transition from quiescent to growing follicles. This study employed comprehensive single-cell RNA sequencing to gain insights into the detailed regulatory mechanisms governing the synchronized dormancy and activation between granulosa cells (GCs) and oocytes with the progression of the PFA process. Wntless (Wls) conditional knockout (cKO) mice served as a unique model, suppressing the transition from pre-GCs to GCs, and disrupting somatic cell-derived WNT signaling in the ovary. Our data revealed immediate transcriptomic changes in GCs post-PFA in Wls cKO mice, leading to a divergent trajectory, while oocytes exhibited modest transcriptomic alterations. Subpopulation analysis identified the molecular pathways affected by WNT signaling on GC maturation, along with specific gene signatures linked to dormant and activated oocytes. Despite minimal evidence of continuous up-regulation of dormancy-related genes in oocytes, the loss of WNT signaling in (pre-)GCs impacted gene expression in oocytes even before PFA, subsequently influencing them globally. The infertility observed in Wls cKO mice was attributed to compromised GC-oocyte molecular crosstalk and the microenvironment for oocytes. Our study highlights the pivotal role of the WNT-signaling pathway and its molecular signature, emphasizing the importance of intercellular crosstalk between (pre-)GCs and oocytes in orchestrating folliculogenesis., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Takase et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The Hedgehog signaling pathway plays a crucial role in folliculogenesis; however, the association between FF-MAS oxysterol activity in folliculogenesis and the Hedgehog signaling pathway has not been revealed. The evaluation of FF-MAS activity in polycystic ovary syndrome (PCOS) with folliculogenesis disorder might provide a new approach to tackle follicular and oocyte maturation failure. The question is: does FF-MAS oxysterol affect granulosa cell (GC) proliferation? If so, is this effect facilitated through the Hedgehog pathway? To answer these questions, GCs were isolated from follicle fluids obtained from patients undergoing oocyte retrieval during in vitro fertilization (IVF) treatment. After the isolated GCs were incubated in different cell culture media, the levels of Hedgehog pathway components (SMO, Gli1) were measured by using immunohistochemical methods, cytoELISA, and qRT-PCR. Meanwhile, cell proliferation rates were determined. Significant increases (p < 0.001) in SMO and Gli1 expressions and cell proliferation were observed in the FF-MAS-treated subgroups of both PCOS and male factor participants compared to the FF-MAS deficient subgroup. Remarkably, FF-MAS positively affected the pathway components despite the pathway inhibitor cyclopamine. Although the increase in Hedgehog pathway components was slightly higher in the male factor group (MF), it was not statistically significant. In our study, we demonstrated for the first time the molecular effect of FF-MAS on human GCs in folliculogenesis. Since FF-MAS is already used in assisted reproductive techniques in animals and is known to be synthesized in the human body, it could be considered a new approach in human IVF treatments., (© 2024. The Author(s).)

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder and metabolic abnormality disease that mainly affects women of reproductive age. LINC00173, a novel long noncoding RNA (lncRNA), has emerged as an important factor in the development of PCOS. However, the role of LINC00173 in PCOS development and its specific upstream and downstream mechanisms remain to be further clarified. Here, we found that LINC00173 was significantly upregulated in granulosa cells (GCs) of PCOS patients, and played a crucial role in promoting apoptosis of GCs. Mechanistically, we observed the activation of endoplasmic reticulum (ER) stress in the GCs of PCOS patients, and the ER stress sensor ATF4 could directly induce LINC00173 expression by binding to its promoter. LINC00173 further upregulated the expression of Harakiri (HRK) and subsequently inhibited downstream PI3K/AKT pathway. In conclusions, our study uncovered that ER stress-induced upregulation of LINC00173 leads to increased HRK expression and inhibition of the PI3K/AKT pathway, thereby promoting the progression of PCOS. These findings provide a new therapeutic strategy for the treatment of PCOS., (© 2024. The Author(s).)

Transfer RNA-derived small RNAs (tsRNAs) are novel regulatory small non-coding RNAs that have been found to modulate many life activities in recent years. However, the exact functions of tsRNAs in follicle development remain unclear. Follicle development is a remarkably complex process that follows a strict hierarchy and is strongly associated with reproductive performance in ducks. The process of converting small yellow follicles into hierarchal follicles is known as follicle selection, which directly determines the number of mature follicles. We performed small RNA sequencing during follicle selection in ducks and identified tsRNA-00764 as the target of interest based on tsRNA expression profiles in this study. Bioinformatics analyses and luciferase reporter assays further revealed that peroxisome proliferator-activated receptor-γ (PPAR-γ) was the target gene of tsRNA-00764. Moreover, tsRNA-00764 knockdown promoted estrogen and progesterone synthesis and lipid deposition in duck granulosa cells, while a PPAR-γ inhibitor reversed the above phenomenon. Taken together, these results demonstrate that tsRNA-00764, differentially expressed in pre-hierarchal and hierarchy follicles, modulates estrogen and progesterone synthesis and lipid deposition by targeting PPAR-γ in duck granulosa cells, serving as a potential novel mechanism of follicle selection. Overall, our findings provide a theoretical foundation for further exploration of the molecular mechanisms underlying follicle development and production performance in ducks.

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder affecting women of reproductive age, affecting reproductive health, and increasing the incidence of diabetes mellitus and hypertension. Metabolic syndrome (MetS) is the most common metabolic disorder. Although clinical studies have shown a close association between PCOS and MetS, the molecular mechanisms are unknown. In this study, datasets of PCOS and MetS were obtained from the Gene Expression Omnibus database; differential expression analysis and weighted gene coexpression network analysis (WGCNA) were performed; and gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses also performed of differentially expressed genes (DEGs). The PCOS- and MetS-coexpressed DEGs were subsequently intersected with the coexpressed genes in the WGCNA module to obtain the core genes. By constructing receiver operating characteristic curves, we verified the predictive effects of the core genes. We also validated the expression of the core genes in the datasets. Finally, we verified the expression of the core genes by quantitative polymerase chain reaction in human follicular fluid granulosa cells. In addition, we used Cell-type Identification By Estimating Relative Subsets Of RNA Transcripts to analyze the immune infiltration of immune cells in PCOS and MetS. Finally, we obtained 52 coexpressed DEGs of PCOS and MetS and 3 coexpressed genes in the WGCNA module. By taking the intersection of coexpressed DEGs and coexpressed genes of the WGCNA module, we get ELOVL fatty acid elongase 7 (ELOVL7) as the core gene. Receiver operating characteristic curve analysis showed that ELOVL7 is a reliable biological marker for PCOS and MetS. The expression level of ELOVL7 in human follicular fluid granulosa cells from PCOS patients was significantly higher than that of controls, as verified by quantitative polymerase chain reaction. This study provides the first evidence of the role of ELOVL7 in developing PCOS and MetS. This gene may serve as a potential diagnostic marker and therapeutic target for both conditions., Competing Interests: The authors declare that the research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Dysfunctional mitochondria producing excessive ROS are the main factors that cause ovarian aging. Immp2l deficiency causes mitochondrial dysfunction and excessive ROS production, leading to ovarian aging, which is attributed to granulosa cell senescence. The pathway controlling mitochondrial proteostasis and mitochondrial homeostasis of the UPR mt and mitophagy are closely related with the ROS and cell senescence. Our results suggest that Immp2l knockout led to granulosa cell senescence, and enocyanin treatment alleviated Immp2l deficiency-induced granulosa cell senescence, which was accompanied by improvements in mitochondrial function and reduced ROS levels. Interestingly, redox-related protein modifications, including S-glutathionylation and S-nitrosylation, were markedly increased in Immp2l -knockout granulosa cells, and were markedly reduced by enocyanin treatment. Furthermore, STAT1 was significantly increased in Immp2l -knockout granulosa cells and reduced by enocyanin treatment. The co-IP results suggest that the expression of STAT1 was controlled by S-glutathionylation and S-nitrosylation, but not phosphorylation. The UPR mt was impaired in Immp2l -deficient granulosa cells, and unfolded and misfolded proteins aggregated in mitochondria. Then, the HIF1α/BNIP3-mediated mitophagy pathway was activated, but mitophagy was impaired due to the reduced fusion of mitophagosomes and lysosomes. The excessive aggregation of mitochondria increased ROS production, leading to senescence. Hence, Enocyanin treatment alleviated granulosa cell senescence through STAT1/ATF4-mediated UPR mt and STAT1/(ATF4)/HIF1α/BNIP3-mediated mitophagy.

Di-(2-ethylhexyl) phthalate (DEHP), an endocrine-disrupting chemical present in plasticized products, exerts strong modulation on the anatomy and function of the female reproductive system. However, the potential mechanisms underlying DEHP-induced regulation of prepubertal female reproductive toxicity have not yet been elucidated. Therefore, this study was designed to elucidate the molecular mechanism of ovarian injury induced by DEHP exposure in mice. Elevated serum mono-2-ethylhexyl phthalate (MEHP) concentrations, decreased levels of ovarian hormones (E2 and P4), and observed ovarian injury were found after DEHP exposure. Ovarian transcriptome analysis revealed significant alterations in ferroptosis-associated gene expression, with potential regulation by Nrf2. Subsequent analysis of ferrous iron, malondialdehyde (MDA), Western blotting, and immunofluorescence of the ovaries confirmed the RNA-seq findings. Transcriptome analysis of granulosa cells revealed a direct or indirect regulatory relationship between Nrf2 and downstream ferroptosis-related proteins following MEHP exposure. Further experiments demonstrated that ferrostatin-1 attenuated MEHP-induced ferroptosis in granulosa cells. Additionally, Nrf2 stabilization and accumulation in the nucleus of granulosa cells were observed following MEHP treatment. RNAi-mediated knockdown of Nrf2 exacerbated MEHP-induced ferroptosis in granulosa cells. This evidence indicates that DEHP exposure induces ferroptosis through regulation of the Nrf2-mediated signaling pathway in mouse ovaries, laying the groundwork for future studies aiming to develop therapeutic strategies against DEHP toxicity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this manuscript., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Copper (Cu) is a common heavy metal and a hazardous environmental pollutant. Emerging epidemiological evidence suggests that Cu exposure is associated with female infertility, especially ovarian dysfunction. However, the mechanisms underlying ovarian toxicity remain poorly understood. Granulosa cells play crucial roles in follicle development and are the main target cells of environmental pollutants for ovarian toxicity. In this study, we investigated the effects of Cu exposure on human granulosa (KGN) cells by using cell biology and metabolomics methods, and explored the molecular mechanisms of Cu-induced cytotoxicity. We found that Cu reduced cell viability in a dose- and time-dependent manner. Then, metabolomic analyses led to the identification of 279, 368 and 466 differentially expressed metabolites (DEMs) in KGN cells exposed to 10, 60 and 240 μM Cu, respectively. Pathway enrichment analysis revealed that high Cu led to disturbances of glutathione metabolism, nucleotide metabolism, glycerophospholipid and ether lipid metabolism. Using cell biological assays, we found that exposure to high Cu significantly decreased the GSH/GSSG ratio and altered the activities of the antioxidant enzymes SOD and CAT. Exposure to high Cu significantly increased the level of mitochondrial ROS. These findings further supported the results revealed by metabolomic analysis and provided clues for elucidating the mechanism by which Cu interferes with the development of ovarian follicles., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Examining the mechanistic cellular responses to heat stress could aid in addressing the increasing prevalence of decreased fertility due to elevated ambient temperatures. Here, we aimed to study the differential responses of oocytes and granulosa cells to thermal fluctuations due to seasonal differences. Dry beef cows (n = 10) were housed together, synchronized and subjected to a stimulation protocol to induce follicular growth before ovum pick-up (OPU). Two OPU's were conducted (summer and winter) to collect cumulus-oocyte-complexes (COCs) and granulosa cells. In addition, rectal temperatures and circulating blood samples were collected during OPU. Oocytes were separated from the adherent cumulus cells, and granulosa cells were isolated from the collected OPU fluid. RNA was extracted from pools of oocytes and granulosa cells, followed by library preparation and RNA-sequencing. Blood samples were further processed for the isolation of plasma and leukocytes. The transcript abundance of HSP70 and HSP90 in leukocytes was evaluated using RT-qPCR, and plasma cortisol levels were evaluated by immunoassay. Environmental data were collected daily for three weeks before each OPU session. Data were analyzed using MIXED, Glimmix or GENMOD procedures of SAS, according to each variable distribution., Results: Air temperatures (27.5 °C vs. 11.5 °C), average max air temperatures (33.7 °C vs. 16.9 °C), and temperature-humidity indexes, THI (79.16 vs. 53.39) were shown to contrast significantly comparing both the summer and winter seasons, respectively. Rectal temperatures (Summer: 39.2 ± 0.2 °C; Winter: 38.8 ± 0.2 °C) and leukocyte HSP70 transcript abundance (Summer: 4.18 ± 0.47 arbitrary units; Winter: 2.69 ± 0.66 arbitrary units) were shown to increase in the summer compared to the winter. No visual differences persisted in HSP90 transcript abundance in leukocytes and plasma cortisol concentrations during seasonal changes. Additionally, during the summer, 446 and 940 transcripts were up and downregulated in oocytes, while 1083 and 1126 transcripts were up and downregulated in the corresponding granulosa cells, respectively (Fold Change ≤ -2 or ≥ 2 and FDR ≤ 0.05). Downregulated transcripts in the oocytes were found to be involved in ECM-receptor interaction and focal adhesion pathways, while the upregulated transcripts were involved in protein digestion and absorption, ABC transporters, and oocyte meiosis pathways. Downregulated transcripts in the granulosa cells were shown to be involved in cell adhesion molecules, chemokine signaling, and cytokine-cytokine receptor interaction pathways, while those upregulated transcripts were involved in protein processing and metabolic pathways., Conclusion: In conclusion, seasonal changes dramatically alter the gene expression profiles of oocytes and granulosa cells in beef cows, which may in part explain the seasonal discrepancies in pregnancy success rates during diverging climatic weather conditions., (© 2024. The Author(s).)

Previous in vitro studies have suggested that SLIT ligands could play roles in regulating ovarian granulosa cell proliferation and gene expression, as well as luteolysis. However, no in vivo study of Slit gene function has been conducted to date. Here, we investigated the potential role of Slit1 in ovarian biology using a Slit1-null mouse model. Female Slit1-null mice were found to produce larger litters than their wild-type counterparts due to increased ovulation rates. Increased ovarian weights in Slit1-null animals were found to be due to the presence of greater numbers of healthy antral follicles with similar numbers of atretic ones, suggesting both an increased rate of follicle recruitment and a decreased rate of atresia. Consistent with this, treatment of cultured granulosa cells with exogenous SLIT1 induced apoptosis in presence or absence of follicle-stimulating hormone, but had no effect on cell proliferation. Although few alterations in the messenger RNA levels of follicle-stimulating hormone-responsive genes were noted in granulosa cells of Slit1-null mice, luteinizing hormone target gene mRNA levels were greatly increased. Finally, increased phospho-AKT levels were found in granulosa cells isolated from Slit1-null mice, and SLIT1 pretreatment of cultured granulosa cells inhibited the ability of both follicle-stimulating hormone and luteinizing hormone to increase AKT phosphorylation, suggesting a mechanism whereby SLIT1 could antagonize gonadotropin signaling. These findings therefore represent the first evidence for a physiological role of a SLIT ligand in the ovary, and define Slit1 as a novel autocrine/paracrine regulator of follicle development., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for the Study of Reproduction.)

Considering the properties of myo-inositol (MI) and D-chiro-inositol (DCI), which are well known in polycystic ovary syndrome therapy, and the limitations of adult granulosa cell tumor (AGCT) treatment, especially for androgen-secreting tumors, we studied the role of MI and DCI in the androgen-rich environment of AGCTs. For this purpose, we analyzed the mRNA expression of steroidogenic genes and the secretion of progesterone (P4) and 17β-estradiol (E2) in an unstimulated and/or dihydrotestosterone (DHT)-stimulated environment under MI and DCI influence. Thus, we used the HGrC1 and KGN cell lines as in vitro models of healthy and cancerous granulosa cells. We found that DHT, the most potent androgen, increased E2 secretion and steroidogenic acute regulatory protein ( StAR ) and cytochrome P450 side-chain cleavage gene ( CYP11A1 ) mRNA expression without affecting 450 aromatase ( CYP19A1 ) in AGCTs. However, after the MI and DCI treatment of KGN cells, both compounds strongly reduced StAR and CYP11A1 expression. Interestingly, in DHT-stimulated KGN cells, only DCI alone and its cotreatment with MI reduced both CYP11A1 mRNA and E2 secretion. These findings suggest that CYP11A1 is responsible for the antiestrogenic effect of DCI in the androgen-rich environment of AGCTs. Therefore, MI and DCI could be used as effective agents in the adjuvant treatment of AGCT, but further detailed studies are needed.

Gossypol (GP), a polyphenolic compound in cottonseed, has notable effects on female reproduction and the respiratory system in pigs. This study aimed to discern the alterations in gene expression within swine granulosa cells (GCs) when treated with two concentrations of GP (6.25 and 12.5 µM) for 72 h, in vitro. The analysis revealed significant changes in the expression of numerous genes in the GP-treated groups. A Gene Ontology analysis highlighted that the differentially expressed genes (DEGs) primarily pertained to processes such as the mitotic cell cycle, chromosome organization, centromeric region, and protein binding. Pathway analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated distinct impacts on various pathways in response to different GP concentrations. Specifically, in the GP6.25 group, pathways related to the cycle oocyte meiosis, progesterone-mediated oocyte maturation, and p53 signaling were prominently affected. Meanwhile, in the GP12.5 group, pathways associated with PI3K-Akt signaling, focal adhesion, HIF-1 signaling, cell cycle, and ECM-receptor interaction showed significant alterations. Notably, genes linked to female reproductive function (CDK1, CCNB1, CPEB1, MMP3), cellular component organization (BIRC5, CYP1A1, TGFB3, COL1A2), and oxidation-reduction processes (PRDX6, MGST1, SOD3) exhibited differential expression in GP-treated groups. These findings offer valuable insights into the changes in GC gene expression in pigs exposed to GP.

Purpose: To reveal the metabolic differences of follicle fluid (FF) and granulosa cell (GC) between younger women and advanced age women in ART cycles, and then find potential therapeutic targets of ovarian aging., Methods: Forty-five patients were included in the study and they were divided into three groups according to their age (Group A: 20-30 years old; Group B: 30-35 years old; Group C: 35-45 years old). All patients underwent controlled ovarian stimulation using the follicular phase long-acting protocol, FF and GC were obtained 36-38 hours after HCG administration. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for metabolomics analysis and metabolic pathway analysis (MetPA) was utilized to find related pathways., Results: Between group A and group C, there were 72 and 21 differential metabolites in FF and GC, respectively. KEGG enrichment analysis showed six pathways were co-enriched by the differential metabolites of FF and GC. Among them, we noticed that in the pathway GABAergic synapse, GABA (gamma-aminobutyric acid) was down-regulated in GC, while its downstream metabolite succinic acid was down-regulated in FF. Further ROC curve analysis was performed on these two metabolites, and the results showed that they all had a favorable predictive value., Conclusion: This study indicated that GABA and succinic acid could be potential therapeutic targets for ovarian aging, GABA may delay ovarian aging and improve ovarian function through its antioxidant properties, which may be a future direction of clinical treatment.

Fragile X mental retardation protein (FMRP) is a translational repressor encoded by FMR1 . It targets bone morphogenetic protein receptor type II (BMPR2), which regulates granulosa cell (GC) function and follicle development. However, whether this interaction affects folliculogenesis remains unclear. Therefore, this study investigated the potential effect of FMRP-BMPR2 dysregulation in ovarian reserves and infertility. COV434 cells and patient-derived GCs were used to evaluate FMRP and BMPR2 expression. Similarly, FMR1 , BMPR2 , LIMK1 , and SMAD expression were evaluated in GCs with normal (NOR) and poor (POR) ovarian responses. FMRP and BMPR2 were expressed in both cell types. They were co-localized to the nuclear membrane of COV434 cells and cytoplasm of primary GCs. FMR1 silencing increased the mRNA and protein levels of BMPR2. However, the mRNA levels of FMR1 and BMPR2 were significantly lower in the POR group. FMR1 and BMPR2 levels were strongly positively correlated in the NOR group but weakly correlated in the POR group. Additionally, SMAD9 expression was significantly reduced in the POR group. This study highlights the crucial role of FMR1 /FMRP in the regulation of BMPR2 expression and its impact on ovarian function. These findings indicate that the disruption of FMRP-BMPR2 interactions may cause poor ovarian responses and infertility.

LncRNAs are highly implicated in oxidative stress (OS) during the growth of mammalian follicles. TAK1 binding protein 2 gene (TAB2) has been suggested to involve in the normal apoptosis and proliferation of granulosa cells (GCs), the main supporting cells in ovarian follicles. In this study, we found that TAB2 increased the expressions of SOD1, P50, and P65 to suppress the OS, thereby inhibiting the apoptosis and promoting the proliferation in GCs. Notably, DNMTs appeared to mediate the expression of TAB2 without the changes of DNA methylation at TAB2's promoter. We identified an antisense lncRNA of TAB2, discovered that DNA methylation regulated the transcription of TAB2-AS in GCs, and found TAB2-AS medicated the follicular growth of ovaries in vivo. Mechanistically, the hypomethylation of the CpG site (-1759/-1760) activated the transcription of TAB2-AS, and the 1-155 nt and 156-241 nt of TAB2-AS were respectively complementary to 4368-4534 nt and 4215-4300 nt of TAB2's mRNA to increase the expression of TAB2. Moreover, TAB2-AS inhibited the OS and apoptosis of GCs, while promoted the proliferation of GCs to expedite the follicular growth, which was in line with that of TAB2. Collectively, these findings revealed the antisense lncRNA mechanism mediated by DNA methylation, and TAB2-AS might be the target to control OS during follicular growth in mammals., (© 2024. The Author(s).)

Sow fertility is an economically important quantitative trait. Hundreds of quantitative trait loci (QTLs) containing tens of thousands of potential candidate genes are excavated. However, among these genes, non-coding RNAs including long non-coding RNAs (lncRNAs) are often overlooked. Here, it is reported that NORSF is a novel causal lncRNA for sow fertility traits in QTLs. QTLs are characterized for sow fertility traits at the genome-wide level and identified 4,630 potential candidate lncRNAs, with 13 differentially expressed during sow follicular atresia. NORSF, a lncRNA that involved in sow granulosa cell (sGC) function, is identified as a candidate gene for sow fertility traits as a G to A transversion at 128 nt in its transcript is shown to be markedly associated with sow fertility traits. Mechanistically, after forming the RNA:dsDNA triplexes with the promoter of Caspase8, NORSF transcript with allele G binds to an RNA-binding protein (RBP) NR2C1 and recruits it to the promoter of Caspase8, to induce Caspase8 transcription in sGCs. Functionally, this leads to a loss of inducing effect of NORSF on sGC apoptosis by inactivating the death receptor-mediated apoptotic pathway. This study identified a novel causal lncRNA that can be used for the genetic improvement of sow fertility traits., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Introduction: Fetal hypoxia has long-term effects on postnatal reproductive functions and the mitochondrial impairments of ovarian granulosa cells may be one of the causes. Melatonin applied to mitigate mitochondrial dysfunction and autophagy in mammalian cells has been reported. However, the potential mechanisms by which fetal hypoxia damages reproductive function in neonatal female mice and the melatonin effects on this problem remain unclear., Objectives: This research aimed to explore the mechanism that fetal hypoxia damages reproductive function in neonatal female mice and attempt to improve the reproductive function by treating with melatonin in vivo and in vitro., Methods: We established a fetal hypoxia model and confirmed that fetal hypoxia affects ovarian function by inducing GC excessive autophagy. Transcriptomic analysis, gene interference, cell immunofluorescence, immunohistochemistry and western blot were conducted to explore and verify the underlying mechanisms in mice GCs and KGN cells. Finally, melatonin treatment was executed on hypoxia-treated mice GCs and KGN cells and melatonin injection to fetal-hypoxia-treated mice to determine its effect., Results: The results of in vitro experiments found that fetal hypoxia led to mitochondrial dysfunction in ovarian GCs causing autophagic cell death. And the PI3K/Akt/FoxO pathway mediated the occurrence of this process by transcriptome analysis of ovarian GCs from normal and fetal hypoxia mice, which was further verified in mice GCs and KGN cells. Additionally, melatonin administration prevented autophagic injuries and mitochondrial impairments in hypoxia-treated mice GCs and KGN cells. Meanwhile, in vivo experiments by melatonin injection ameliorated oxidative stress of ovary in fetal-hypoxia-treated mice and improved their low fertility., Conclusion: Our data found that fetal hypoxia causes ovarian GCs excessive autophagy leading to low fertility in neonatal female mice and mitigated by melatonin. These results provide a potential therapy for hypoxic stress-related reproductive disorders., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Production and hosting by Elsevier B.V.)

Quercetin has been shown to mitigate the cytotoxic effects of heavy metals. While copper is an essential trace element for bodily functions, excessive intake has been linked to impaired female reproductive function. Transcriptome analysis was employed to identify genes that are differentially expressed in response to high copper and were validated through qRT-PCR and western blotting. ATP content and Tunel were used to identify the damage of mitochondrial and cell apoptosis. PPI analysis revealed that MKI67, TOPII, ASPM, CASP3, PLK1, and TTK are central proteins within the network. Additionally, exposure to elevated levels of copper resulted in the dysregulation of 86 genes associated with mitochondria. Conversely, treatment with quercetin (QUE) in combination with high copper led to the normalization of 42 mitochondria-related genes previously affected by high copper levels. Furthermore, CuSO 4 decreases ATP content and induces cell apoptosis, which can be reversed by QUE. Results suggest that elevated copper levels could lead to oxidative stress and apoptosis by inducing mitochondrial damage, while QUE has the potential to mitigate these effects, ultimately safeguarding granulosa cells and halting the progression of cell death. This study provides novel insights into the molecular pathways involved in female reproductive toxicity caused by excessive copper exposure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Lipid droplets (LDs) are endoplasmic reticulum-derived organelles that store neutral lipids (mostly triglycerides and cholesterol esters) within a phospholipid monolayer and appear in most eukaryotic cells. Perilipins (PLINs, comprising PLIN1-5) are abundant LD-associated proteins with highly variable expression levels among tissues. Although PLINs are expressed in the mammalian ovaries, little is known about their subcellular localization and physiological functions. In this study, we investigated the localization of PLIN1-3 and their relationship with LD synthesis using mCherry-HPos reporter mice, thereby enabling the visualization of LD biogenesis in vivo. PLIN2 and PLIN3 were localized as puncta in granulosa cells with low levels of LD synthesis in developing follicles. This localization pattern was quite different from that of PLIN1, which was mainly localized in the theca and interstitial cells with high levels of LD synthesis. In the corpus luteum, where LD synthesis is highly induced, PLIN2 and PLIN3 are abundant in the particulate structures, whereas PLIN1 is poorly distributed. We also generated global Plin2-deficient mice using the CRSPR/Cas9 system and demonstrated that the lack of PLIN2 did not alter the distribution of PLIN1 and PLIN3 but unexpectedly induced LD enlargement in the corpus luteum. Collectively, our results suggest that the localization of PLIN1-3 is spatiotemporally regulated and that PLIN2 deficiency influences LD mobilization in the corpus luteum within the ovaries.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by chronic ovulation dysfunction and overproduction of androgens. Women with PCOS are commonly accompanied by insulin resistance (IR), which can impair insulin sensitivity and elevate blood glucose levels. IR promotes ovarian cysts, ovulatory dysfunction, and menstrual irregularities in women patients, leading to the pathogenesis of PCOS. Secreted frizzled-related protein 4 (SFRP4), a secreted glycoprotein, exhibits significantly elevated expression levels in obese individuals with IR and PCOS. Whereas, whether it plays a role in regulating IR-induced PCOS still has yet to be understood. In this study, we respectively established in vitro IR-induced hyperandrogenism in human ovarian granular cells and in vivo IR-induced PCOS models in mice to investigate the action mechanisms of SFRP4 in modulating IR-induced PCOS. Here, we revealed that SFRP4 expression levels in both mRNA and protein were remarkably upregulated in the IR-induced hyperandrogenism with elevated testosterone in the human ovarian granulosa cell line KGN. Under normal conditions without hyperandrogenism, overexpressing SFRP4 triggered the remarkable elevation of testosterone along with the increased nuclear translocation of β-catenin, cell apoptosis and proinflammatory cytokine IL-6. Furthermore, we found that phytopharmaceutical disruption of SFRP4 by genistein ameliorated IR-induced increase in testosterone in ovarian granular cells, and IR-induced PCOS in high-fat diet obese mice. Our study reveals that SFRP4 contributes to IR-induced PCOS by triggering ovarian granulosa cell hyperandrogenism and apoptosis through the nuclear β-catenin/IL-6 signaling axis. Elucidating the role of SFRP4 in PCOS may provide a novel therapeutic strategy for IR-related PCOS therapy., Competing Interests: Declaration of competing interest No conflict of interest exists in the submission of this manuscript. All authors have read and approved submission of the manuscript and the manuscript has not been published and is not being considered for publication elsewhere in whole or in part in any language, including publicly accessible Websites or e-print servers., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Ovarian aging, a complex and challenging concern within the realm of reproductive medicine, is associated with reduced fertility, menopausal symptoms and long-term health risks. Our previous investigation revealed a correlation between Peroxiredoxin 4 (PRDX4) and human ovarian aging. The purpose of this research was to substantiate the protective role of PRDX4 against ovarian aging and elucidate the underlying molecular mechanism in mice. In this study, a Prdx4 -/- mouse model was established and it was observed that the deficiency of PRDX4 led to only an accelerated decline of ovarian function in comparison to wild-type (WT) mice. The impaired ovarian function observed in this study can be attributed to an imbalance in protein homeostasis, an exacerbation of endoplasmic reticulum stress (ER stress), and ultimately an increase in apoptosis of granulosa cells. Furthermore, our research reveals a noteworthy decline in the expression of Follicle-stimulating hormone receptor (FSHR) in aging Prdx4 -/- mice, especially the functional trimer, due to impaired disulfide bond formation. Contrarily, the overexpression of PRDX4 facilitated the maintenance of protein homeostasis, mitigated ER stress, and consequently elevated E2 levels in a simulated KGN cell aging model. Additionally, the overexpression of PRDX4 restored the expression of the correct spatial conformation of FSHR, the functional trimer. In summary, our research reveals the significant contribution of PRDX4 in delaying ovarian aging, presenting a novel and promising therapeutic target for ovarian aging from the perspective of endoplasmic reticulum protein homeostasis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Ovarian granulosa cells (GCs) play crucial roles in follicular growth and development. Their normal function is influenced by various factors, including oxidative stress, which is a significant factor. Afamin protein is a vitamin E-specific binding protein that acts as a vitamin E carrier in follicular fluid. Although the mechanism of the protective effect of afamin on human ovarian GCs is still unclear, there is evidence it has an antioxidant effect in neuronal cells., Methods: In this study, we investigated the protective effects of afamin proteins on testosterone propionate (TP)-induced ovarian GCs using a human ovarian tumor granulosa cell line (KGN)., Results: The results showed that afamin reduced TP-induced oxidative stress in KGN cells by decreasing the levels of oxidative damage markers, enhancing the activity of antioxidant enzymes, and exerting a protective effect on GCs. Supplementation with afamin repaired mitochondrial dysfunction by improving mitochondrial membrane potential damage and ATP levels. It counteracted TP-induced apoptosis by decreasing the activity of Caspase-3 and upregulating the expression of the anti-apoptotic gene (BCL-2) while downregulating the expression of the pro-apoptotic gene BCL-2-associated X protein (BAX). In addition, afamin regulated the expression of genes related to ovarian steroid hormone synthesis, ameliorating the endocrine dysfunction observed in TP-induced KGN cells., Conclusion: Therefore, Afamin proteins may serve as important complementary factors that protect GCs from other types of damage, such as oxidative stress, and may help improve ovarian follicle quality and female reproductive function., (© 2024. The Author(s).)

Background: Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disease in women of childbearing age, making it imperative to explore more biomarkers for PCOS. Furthermore, previous studies have reported that cyclin dependent kinase inhibitor 1 C (CDKN1C) might be associated with PCOS progression. However, the molecular mechanism of CDKN1C involved in PCOS is poorly defined., Methods: CDKN1C and Yin-Yang-1 (YY1) expression levels were determined using real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot assay. Cell viability, proliferation, cell cycle progression, and cell apoptosis were analyzed using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry assays. Caspase 3 activity was examined using a commercial kit. Binding between YY1 and CDKN1C promoter was predicted by JASPAR and verified using Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays., Results: CDKN1C and YY1 were highly expressed in PCOS granulosa cells (GCs). Furthermore, CDKN1C silencing could promote cell proliferation and cell cycle process and repress cell apoptosis in human ovarian granulosa cell line KGN cells. For mechanistic analysis, YY1 is directly bound to the promoter of CDKN1C and transcriptional-regulated CDKN1C expression., Conclusion: YY1-activated CDKN1C might block KGN cell proliferation and induce cell apoptosis, providing a possible therapeutic target for PCOS treatment., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Ovarian cysts are linked to hormone imbalances and altered gene expressions, but the connection between cysts and ion channel expression is understudied. This study explored the role of TWIK-related acid-sensitive K + (TASK) channels in bovine ovarian cyst formation. The ovarian follicles were split into small (5 to 10 mm in diameter) and large (>25 mm in diameter) groups. Among the measured K + , Na + , and Cl - concentrations in follicular fluid (FF) obtained from small-sized follicles (SFs) and large-sized follicles (LFs), the K + concentration was significantly lower in LFFF. Quantitative PCR, Western blot, and immunocytochemistry data revealed that TASK-3 expression levels significantly decreased by approximately 50% in LFs and granulosa cells obtained from LFs (LFGCs) compared to the corresponding controls. The TASK-3 protein was localized to the plasma membranes of GCs. The diameters of LFGCs were larger than those of SFGCs. The cell swelling response to exposure to a hypotonic solution (200 mOsm/L) was highly reduced in TASK-3-overexpressing cells compared to vector-transfected cells. TASK-3-knockdown cells showed arrested growth. Senescence markers were detected in LFGCs and TASK-3-knockdown cells. These findings suggest that reduced TASK-3 expression in LFs is associated with the inhibition of GC growth, leading to senescence and cyst formation.

Circular RNAs (circRNAs) are a class of circular non-coding RNAs that play essential roles in the intricate and dynamic networks governing cell growth, development, and apoptosis. Resveratrol (RSV), a non-flavonoid polyphenol, is known to participate in follicular development and ovulation. In our previous research, we established a model using porcine ovarian granulosa cells (POGCs) treated with resveratrol, which confirmed its regulatory effects on long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) within these cells. However, the influence of resveratrol on circRNA expression has not been thoroughly investigated. To explore how resveratrol affects circRNA levels in POGCs, we designed an experiment with three groups: a control group (CON, n = 3, 0 μM RSV), a low-dose RSV group (LOW, n = 3, 50 μM RSV), and a high-dose RSV group (HIGH, n = 3, 100 μM RSV) for circRNA sequencing. We identified a total of 10,045 candidate circRNAs from POGCs treated with different concentrations of resveratrol (0, 50, and 100 μM). Differential expression analysis indicated that 96 circRNAs were significantly altered in the LOW vs. CON group, while 109 circRNAs showed significant changes in the HIGH vs. CON group. These circRNAs were notably enriched in biological processes associated with cell metabolism, apoptosis, and oxidative stress. Functional enrichment analysis of the host genes revealed their involvement in critical signaling pathways, including mTOR, AMPK, and apoptosis pathways. Additionally, we identified potential miRNA sponge candidates among the differentially expressed circRNAs, particularly novel&#95;circ&#95;0012954 and novel&#95;circ&#95;0004762, which exhibited strong connectivity within miRNA-target networks. Our findings provide valuable insights into the regulatory mechanisms of circRNAs in the context of resveratrol-induced apoptosis in POGCs, highlighting their potential as innovative therapeutic targets in reproductive biology.