Protease Expression in the Human and Rat Cumulus Oocyte Complex (COC) During the Periovulatory Period: A Role in COC Migration.

The migratory and matrix-invading capacities of the cumulus oocyte complex (COC) have been shown to be important for the ovulatory process. In metastatic cancers, these capacities are due to increased expression of proteases, however, there is limited information on protease expression in the COCs. The present study examined COC expression of plasmins, matrix metalloproteases (MMP) and A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTS) family members in the rat and human. In the rat, hCG administration increased COC expression of Mmp2, Mmp9, Mmp13, Mmp14, Mmp16, Adamts1, and the protease inhibitors Timp1, Timp3 and Serpine1 by 8-12 hours. This ovulatory induction of proteases in vivo could be mimicked by forskolin and ampiregulin treatment of cultured rat COCs with increases observed in Mmp2, Mmp13, Mmp14, Mmp16, Mmp19, Plat, and the protease inhibitors Timp1, Timp3 and Serpine1. Comparison of expression between rat COCs and granulosa cells at the time of ovulation showed decreased Mmp9 and increased Mmp13, Mmp14, Mmp16, Adamts1, Timp1 and Timp3 expression in the COCs. In human, comparison of expression between cumulus and granulosa cells at the time of IVF retrieval showed decreased MMP1, MMP2, MMP9, and ADAMTS1, while expression of MMP16, TIMP1, and TIMP3 were increased. Treatment of expanding rat COCs with a broad spectrum MMP inhibitor, GM6001, significantly reduced the migration of cumulus cells in vitro. These data provide evidence that multiple proteases and their inhibitors are expressed in the COCs and play an important role in imparting the migratory phenotype of the COCs at the time of ovulation.

Diaph1 knockout inhibits mouse primordial germ cell proliferation and affects gonadal development.

BACKGROUND: Exploring the molecular mechanisms of primordial germ cell (PGC) migration and the involvement of gonadal somatic cells in gonad development is valuable for comprehending the origins and potential treatments of reproductive-related diseases. METHODS: Diaphanous related formin 1 (Diaph1, also known as mDia1) was screened by analyzing publicly available datasets (ATAC-seq, DNase-seq, and RNA-seq). Subsequently, the CRISPR-Cas9 technology was used to construct Diaph1 knockout mice to investigate the role of Diaph1 in gonad development. RESULTS: Based on data from public databases, a differentially expressed gene Diaph1, was identified in the migration of mouse PGC. Additionally, the number of PGCs was significantly reduced in Diaph1 knockout mice compared to wild type mice, and the expression levels of genes related to proliferation (Dicer1, Mcm9), adhesion (E-cadherin, Cdh1), and migration (Cxcr4, Hmgcr, Dazl) were significantly decreased. Diaph1 knockout also inhibited Leydig cell proliferation and induced apoptosis in the testis, as well as granulosa cell apoptosis in the ovary. Moreover, the sperm count in the epididymal region and the count of ovarian follicles were significantly reduced in Diaph1 knockout mice, resulting in decreased fertility, concomitant with lowered levels of serum testosterone and estradiol. Further research found that in Diaph1 knockout mice, the key enzymes involved in testosterone synthesis (CYP11A1, 3ß-HSD) were decreased in Leydig cells, and the estradiol-associated factor (FSH receptor, AMH) in granulosa cells were also downregulated. CONCLUSIONS: Overall, our findings indicate that the knockout of Diaph1 can disrupt the expression of factors that regulate sex hormone production, leading to impaired secretion of sex hormones, ultimately resulting in damage to reproductive function. These results provide a new perspective on the molecular mechanisms underlying PGC migration and gonadal development, and offer valuable insights for further research on the causes, diagnosis, and treatment of related diseases.

Collision Tumor of the Ovary: Adult Granulosa Cell Tumor and Mesonephric-like Adenocarcinoma.

Collision tumors of the ovaries are rare, with only a few reports in the literature. Adult granulosa cell tumors are a relatively common primary tumor component of previously reported collision tumors. The combination of serous and mucinous tumors with adult granulosa cell tumors has been reported in several cases. On the other hand, mesonephric-like adenocarcinomas are rare neoplasms that commonly arise in the uterine corpus and ovaries. In this report, we present the case of a collision tumor composed of an adult granulosa cell tumor and mesonephric-like adenocarcinoma of the ovary in a 63-year-old woman. The initial magnetic resonance imaging findings showed a cystic mass with an internal hemorrhage, which suggested an adult granulosa cell tumor, and a solid mass with different enhancements. Microscopically, the tumor had two distinct components: An adult granulosa cell tumor and a mesonephric-like adenocarcinoma. Recognizing collision tumors consisting of slow-growing and aggressive tumors may prove beneficial in future diagnostic and treatment strategies.

MTHFR as a Novel Candidate Marker for Litter Size in Rabbits.

Litter size is a significant economic trait during animal reproduction. This current study attempted to decipher whether MTHFR promotes the apoptosis of granulosa cells (GCs) and inhibits their proliferation by investigating the effects of the MTHFR gene using flow cytometry and a Cell Counting Kit-8 (CCK-8) assay. MTHFR is linked with ovarian follicle development in the reproductive performance of 104 female New Zealand rabbits. We observed that MTHFR could regulate the mRNA of follicular development-related genes (TIMP1, CITED1, FSHR, GHR, HSD17B1, and STAR) with a qRT-PCR, and we observed the protein expression of CITED1 and GHR using a western blot (WB) analysis. The dual luciferase activity assays helped identify the core promoter region of the MTHFR gene, and the polymorphism of the MTHFR promoter region was studied using Sanger sequencing. The results indicated four single nucleotide polymorphisms (SNPs) within the core promoter region, among which the g.-680C>A locus was significantly associated with both the total and alive litter sizes. Additionally, the CC genotype was associated with the largest total and alive litter sizes, compared to the CA and AA genotypes (p < 0.05). In conclusion, this study investigated the effects of MTHFR on ovarian granulosa cells and its association with selected reproductive parameters in rabbits. The results provide a theoretical foundation for the use of MTHFR as a molecular marker in rabbits.

Resveratrol ameliorates mitochondrial biogenesis and reproductive outcomes in women with polycystic ovary syndrome undergoing assisted reproduction: a randomized, triple-blind, placebo-controlled clinical trial.

BACKGROUND: This study was designed to examine the effect of resveratrol on mitochondrial biogenesis, oxidative stress (OS), and assisted reproductive technology (ART) outcomes in individuals with polycystic ovary syndrome (PCOS). METHODS: Fifty-six patients with PCOS were randomly assigned to receive 800 mg/day of resveratrol or placebo for 60 days. The primary outcome was OS in follicular fluid (FF). The secondary outcome involved assessing gene and protein expression related to mitochondrial biogenesis, mitochondrial DNA (mtDNA) copy number, and adenosine triphosphate (ATP) content in granulosa cells (GCs). ART outcomes were evaluated at the end of the trial. RESULTS: Resveratrol significantly reduced the total oxidant status (TOS) and oxidative stress index (OSI) in FF (P = 0.0142 and P = 0.0039, respectively) while increasing the total antioxidant capacity (TAC) (P < 0.0009). Resveratrol consumption also led to significant increases in the expression of critical genes involved in mitochondrial biogenesis, including peroxisome proliferator-activated receptor gamma coactivator (PGC-1α) and mitochondrial transcription factor A (TFAM) (P = 0.0032 and P = 0.0003, respectively). However, the effect on nuclear respiratory factor 1 (Nrf-1) expression was not statistically significant (P = 0.0611). Resveratrol significantly affected sirtuin1 (SIRT1) and PGC-1α protein levels (P < 0.0001 and P = 0.0036, respectively). Resveratrol treatment improved the mtDNA copy number (P < 0.0001) and ATP content in GCs (P = 0.0014). Clinically, the resveratrol group exhibited higher rates of oocyte maturity (P = 0.0012) and high-quality embryos (P = 0.0013) than did the placebo group. There were no significant differences between the groups in terms of chemical or clinical pregnancy rates (P > 0.05). CONCLUSIONS: These findings indicate that resveratrol may be a promising therapeutic agent for patients with PCOS undergoing assisted reproduction. TRIAL REGISTRATION NUMBER: http://www.irct.ir ; IRCT20221106056417N1; 2023 February 09.

CircRNAs involved in the red light of effect on follicle selection in pigeons.

Red light (RL) can enhance egg production in poultry. CircRNAs play a crucial role by serving as transcriptional regulators. However, their role in influencing follicle development in White King pigeons remains unexplored. In this study, 54 paired White King pigeons were chosen and divided into RL and white light (WL) groups, each with 3 subgroups. The egg production of paired pigeons in each replicate was recorded for 45 d, and the characteristics of follicle development were monitored during the laying interval (LI). The granulosa cell layer from follicles of the second-largest follicle (F2) was collected, and high-throughput sequencing was performed to elucidate the molecular mechanism of follicle development in pigeons. The study confirmed that RL enhances egg production in pigeons. Additionally, under RL, the F2 follicle was selected, while under WL, small follicles were kept on the third day (LI3). A total of 5,510 circRNAs were identified across all samples, revealing differentially expressed circRNAs (DECs) in various comparisons: 627 in RF1 vs. WF1, 900 in RF2 vs. WF2, 606 in RF1 vs. RF2, and 937 in WF1 vs. WF2. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that host genes of DECs were enriched in pathways like steroid hormone biosynthesis, oocyte meiosis, GnRH signaling pathway, and apoptosis pathway. Moreover, circRNA_5497, circRNA_2016, and circRNA_3328 were common DECs across 4 groups, sharing miRNA binding sites with follicle selection-associated genes. In conclusion, our findings suggest that RL promotes egg production by stimulating follicle selection during LI, offering insights into the regulatory mechanisms of circRNAs in follicle selection under RL. This knowledge can help enhance the reproductive performance of pigeons.

Basket study of oral progesterone antagonist onapristone extended release in progesterone receptor-positive recurrent granulosa cell, low-grade serous ovarian cancer, or endometrioid endometrial cancer.

OBJECTIVE: To determine the safety and efficacy of the oral progesterone antagonist onapristone extended release (onapristone-XR) in patients with recurrent progesterone receptor (PR)-positive adult-type granulosa cell tumor (aGCT), low-grade serous ovarian cancer (LGSOC), or endometrioid endometrial cancer (EEC). METHODS: This single-institution phase II study included patients with PR-positive aGCT, LGSOC, or EEC who received ≥1 prior line of chemotherapy. Patients were enrolled from 5/2019-5/2020. PR status was evaluated via immunohistochemistry. Eligible patients had PR expression ≥1% on tissue collected within 3 years of enrollment. Patients received 50 mg of onapristone-XR twice daily until disease progression or treatment discontinuation. Adverse events were graded by Common Terminology Criteria for Adverse Events version 5.0. The primary endpoint was overall response rate (ORR) by Response Evaluation Criteria in Solid Tumors 1.1. Secondary endpoints were response duration, clinical benefit rate (CBR), and safety. RESULTS: Five patients with LGSOC and 1 with EEC enrolled, but both cohorts closed early due to slow accrual. Fourteen patients with aGCT enrolled and completed stage 1 accrual. No responses were observed. Four patients with LGSOC were evaluable, with median PFS of 4.4 months (range, 1.8-NE) and CBR of 50% (range, 6.8%-93.2%). All 14 patients with aGCT were evaluable, with median PFS of 2.8 months (range, 1.6-4.9), 6-month PFS rate of 21.4% (range, 5.2%-44.8%), 12-month PFS rate of 14.3% (range, 2.3%-36.6%), and a CBR of 35.7% (range, 12.8%-64.9%). CONCLUSIONS: The study did not meet its primary endpoint. While onapristone-XR was well tolerated in all 3 arms, no objective responses were observed.

Therapeutic effects of curculigoside on cyclophosphamide-induced premature ovarian failure in mice.

OBJECTIVE: The main purpose of this study was to elucidate the anti-apoptotic effects of curculigoside (CUR) on ovarian granulosa cells (GCs) in a mouse model of cyclophosphamide (CTX)-induced premature ovarian failure (POF). METHOD: Intraperitoneal injection of CTX (100 mg/kg body weight) induced POF in mice. Thirty-six female mice were divided into six groups: blank group; POF model group; low-dose CUR group; medium-dose CUR group; high-dose CUR group; and estradiol benzoate group. Mice were orally administered for 28 consecutive days. Twenty-four hours after the completion of treatment, mice were weighed and euthanized, and blood was collected from the eyeball under anesthesia. The ovaries were surgically separated and weighed, and the ovarian index was calculated. Hematoxylin-eosin (HE) staining was used to observe follicular development and corpus luteum morphology in the ovaries. Serum levels of follicle stimulating hormone (FSH), anti-Müllerian hormone (AMH) and estradiol (E2) were measured. Superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) content and malondialdehyde (MDA) levels in ovarian tissue were determined. The GC apoptosis level was measured. Western blotting was used to detect protein expression levels of Beclin-1, LC3, P62, AKT, p-AKT, mTOR and p-mTOR in the ovaries. RESULTS: The results showed that CUR can improve body weight and ovarian index; promote follicular development and reduce follicular atresia; improve FSH, AMH and E2 levels; downregulate MDA levels and restore antioxidant enzyme activity; inhibit the autophagy level; activate the AKT/mTOR signaling pathway; and alleviate GC apoptosis. CONCLUSION: CUR improves POF by activating the AKT/mTOR signaling pathway, inhibiting autophagy and alleviating GC apoptosis.

Mitochondrial Quality Control in Ovarian Function: From Mechanisms to Therapeutic Strategies.

Mitochondrial quality control plays a critical role in cytogenetic development by regulating various cell-death pathways and modulating the release of reactive oxygen species (ROS). Dysregulated mitochondrial quality control can lead to a broad spectrum of diseases, including reproductive disorders, particularly female infertility. Ovarian insufficiency is a significant contributor to female infertility, given its high prevalence, complex pathogenesis, and profound impact on women's health. Understanding the pathogenesis of ovarian insufficiency and devising treatment strategies based on this understanding are crucial. Oocytes and granulosa cells (GCs) are the primary ovarian cell types, with GCs regulated by oocytes, fulfilling their specific energy requirements prior to ovulation. Dysregulation of mitochondrial quality control through gene knockout or external stimuli can precipitate apoptosis, inflammatory responses, or ferroptosis in both oocytes and GCs, exacerbating ovarian insufficiency. This review aimed to delineate the regulatory mechanisms of mitochondrial quality control in GCs and oocytes during ovarian development. This study highlights the adverse consequences of dysregulated mitochondrial quality control on GCs and oocyte development and proposes therapeutic interventions for ovarian insufficiency based on mitochondrial quality control. These insights provide a foundation for future clinical approaches for treating ovarian insufficiency.

Per2 mediated steroid hormone synthesis by regulating transcription of StAR in porcine granulosa cells.

Steroidogenesis is associated with circadian clock genes. However, the regulation of steroid hormone production in sow granulosal cells by Per2, a crucial circadian regulator, remains unexplored. In this study, we have identified the presence of Per2 in ovarian granulosa cells and have observed its circadian expression pattern. Employing siRNA to interfere with Per2 expression, our investigation revealed that Per2 knockdown notably elevated progesterone (P4) levels along with increasing the expression of StAR but interference of Per2 did not alter the rhythm of clock-related gene (Bmal1, Clock, Per1 and Cry1) in granulosa cells. Subsequent mechanistic analysis showed that Per2 formed complexes with PPARγ and interference with Per2 promoted the formation of the PPARγ:RXRα heterodimer. Importantly, we uncovered that PPARγ:RXRα heterodimer could control the expression of StAR via direct peroxisome proliferator response element (PPRE) binding to its promoter to regulate its activity, and knockdown of Per2 promoted the transcription of StAR via increasing the binding of PPARγ:RXRα ligands. Altogether, these findings indicated a noncanonical role of Per2 in controlling PPARγ:RXRα binding to regulate transcription of StAR and progesterone synthesis, thus revealing potential avenues of pharmacological and therapeutic intervention.

An Approach to Improve Endometrial Receptivity: Is It Beneficial to Flush The Uterine Cavity with Follicular Fluid and Granulosa Cells? A Phase III Randomised Clinical Trial.

BACKGROUND: The follicular fluid (FF) of mature oocytes contains a high concentration of growth factors and cytokines that have the potential to influence implantation in either a paracrine or autocrine manner. During the physiological processes of ovulation, FF enters the fallopian tubes in conjunction with the oocyte. The purpose of this study is to evaluate implantation and clinical pregnancy rates following uterine flushing with FF and granulosa cells in infertile women with moderate male factor infertility after ovum retrieval for intracytoplasmic sperm injection (ICSI). MATERIALS AND METHODS: This phase III randomised clinical trial enrolled 140 women with moderate male factor infertility who intended to undergo ICSI at Royan Infertility Clinic (Tehran, Iran). A computer-generated program and opaque sealed envelopes were used to randomly allocate patients to either an intervention group (n=70) or a control group (n=70). Participants in the intervention group received 2 ml of clear FF (without blood contamination) from 2 to 3 dominant follicles after oocyte retrieval. The control group only underwent uterine cavity catheterisation. RESULTS: The intervention group had a clinical pregnancy rate of 38.5% (25/65) compared to the control group [42.9% (27/63); P=0.719] and an implantation rate of 24.1% compared to the control group (27%; P=0.408). These rates did not differ between the groups. There were no statistically significant differences between the intervention and control groups in terms of pregnancy-related complications-ectopic pregnancy, blighted ovum or anembryonic pregnancy, and abortion. CONCLUSION: Uterine cavity flushing with FF from mature follicles following oocyte retrieval had no effect, either positively or negatively, on clinical pregnancy or implantation rates in women with moderate male factor infertility (registration number: NCT04077970).

Single-cell transcriptomic profiling unveils insights into ovarian fibrosis in obese mice.

BACKGROUND: Adiposity profoundly impacts reproductive health in both humans and animals. However, the precise subpopulations contributing to infertility under obese conditions remain elusive. RESULTS: In this study, we established an obese mouse model through an eighteen-week high-fat diet regimen in adult female mice. Employing single-cell RNA sequencing (scRNA-seq), we constructed a comprehensive single-cell atlas of ovarian tissues from these mice to scrutinize the impact of obesity on the ovarian microenvironment. ScRNA-seq revealed notable alterations in the microenvironment of ovarian tissues in obese mice. Granulosa cells, stromal cells, T cells, and macrophages exhibited functional imbalances compared to the control group. We observed heightened interaction strength in the SPP1-CD44 pairing within lgfbp7+ granulosa cell subtypes and Il1bhigh monocyte subtypes in the ovarian tissues of obese mice. Moreover, the interaction strength between Il1bhigh monocyte subtypes and Pdgfrb+ stromal cell subtypes in the form of TNF - TNFrsf1α interaction was also enhanced subsequently to obesity, potentially contributing to ovarian fibrosis pathogenesis. CONCLUSIONS: We propose a model wherein granulosa cells secrete SPP1 to activate monocytes, subsequently triggering TNF-α secretion by monocytes, thereby activating stromal cells and ultimately leading to the development of ovarian fibrosis. Intervening in this process may represent a promising avenue for improving clinical outcomes in fertility treatments for obese women.

The modulating effects of astaxanthin on apoptosis in women with polycystic ovarian syndrome: A randomized clinical trial.

Objective: Astaxanthin (ASX) is a lipid-soluble keto-carotenoid with several biological effects. These effects may benefit polycystic ovarian syndrome (PCOS) patients. Imbalanced apoptosis/anti-apoptosis signaling has been considered the major pathogenesis of PCOS. In a randomized clinical trial, we tested the impact of ASX on the apoptotic pathway in PCOS granulosa cells (GCs). The present study hypothesizes that ASX may improve apoptosis in PCOS patients. Materials and Methods: This trial recruited patients with confirmed PCOS. A total of 58 patients were randomly assigned to take ASX (12 mg) or placebo for 8 weeks. Aspirated follicular fluid (FF) and blood samples were taken from both groups to measure BAX and BCL2 protein expression. Following FF aspiration, GCs from both groups were obtained; Real-Time PCR and Western blotting were used to evaluate the apoptotic pathway's gene and protein expression levels in GCs.BAXBCL2. Results: In GCs analysis, ASX reduced DR5 gene and protein expression after 8 weeks compared to placebo(p<0.05). Also, Caspase8 (p>0.05) and BAX (p<0.05) gene expression declined, although the difference was not statistically significant for Caspase8. Besides,ASX treatment contributed to an elevated BCL2 gene expression in GCs(p<0.05). In FF and serum analysis, a statistically significant increase was found in BCL2 concentration in the ASX group (p<0.05). Moreover, a reduction in BAX level was confirmed in both FF and serum of the ASX group; however, this change was not significant in the serum (p>0.05). Conclusion: It seems that ASX consumption among women with PCOS improved serum and FF levels of apoptotic factors and modulated genes and protein expression of the apoptosis pathway in GCs. Nevertheless, further investigations are needed to reveal the potential role of this compound in PCOS treatment.

Telomerase activity, telomere length, and the euploidy rate of human embryos.

BACKGROUND: Telomeres maintain chromosome stability, while telomerase counteracts their progressive shortening. Telomere length varies between cell types, with leukocyte telomere length (LTL) decreasing with age. Reduced telomerase activity has been linked to reproductive issues in females, such as low pregnancy rates and premature ovarian failure, with recent studies indicating correlations between telomere length in granulosa cells and IVF outcomes. OBJECTIVES: The study aims to explore the relationship between telomere length, telomerase activity, and euploid blastocyst rate in infertile women undergoing IVF/ICSI PGT-A cycles. METHODS: This prospective study involves 108 patients undergoing controlled ovarian stimulation and PGT-A. Telomere length and telomerase activity were measured in peripheral mononuclear cells and granulosa cells (GC), respectively. RESULTS: The telomere repeat copy number to single gene copy number ratio (T/S) results respectively 0.6 ± 0.8 in leukocytes and 0.7 ± 0.9 in GC. An inverse relationship was found between LTL and the patient's age (p < .01). A higher aneuploid rate was noticed in patients with short LTL, with no differences in ovarian reserve markers (p = .15), number of oocytes retrieved (p = .33), and number of MII (p = 0.42). No significant association was noticed between telomere length in GC and patients' age (p = 0.95), in ovarian reserve markers (p = 0.32), number of oocytes retrieved (p = .58), number of MII (p = .74) and aneuploidy rate (p = .65). CONCLUSION: LTL shows a significant inverse correlation with patient age and higher aneuploidy rates. Telomere length in GCs does not correlate with patient age or reproductive outcomes, indicating differential telomere dynamics between leukocytes and granulosa cells.

Granulosa Cell-Layer Stiffening Prevents Escape of Mural Granulosa Cells from the Post-Ovulatory Follicle.

Ovulation is vital for successful reproduction. Following ovulation, cumulus cells and oocyte are released, while mural granulosa cells (mGCs) remain sequestered within the post-ovulatory follicle to form the corpus luteum. However, the mechanism underlying the confinement of mGCs has been a longstanding mystery. Here, in vitro and in vivo evidence is provided demonstrating that the stiffening of mGC-layer serves as an evolutionarily conserved mechanism that prevents mGCs from escaping the post-ovulatory follicles. The results from spatial transcriptome analysis and experiments reveal that focal adhesion assembly, triggered by the LH (hCG)-cAMP-PKA-CREB signaling cascade, is necessary for mGC-layer stiffening. Disrupting focal adhesion assembly through RNA interference results in stiffening failure, mGC escape, and the subsequent development of an abnormal corpus luteum characterized by decreased cell density or cavities. These findings introduce a novel concept of "mGC-layer stiffening", shedding light on the mechanism that prevents mGC escape from the post-ovulatory follicle.

Extremely late recurrence of adult granulosa cell tumor in the retroperitoneal space 27 years after surgery manifesting as a liver tumor.

We present a patient with an extremely late and rare manifestation of recurrent AGCTs. After 27 years, the recurrence of the disease is unlikely, and the manifestation of liver lymphatic cavernoma is not a premise for suspicion of AGCT recurrence. The retroperitoneal site of recurrence is also very rare, and surgical resection of the tumor may not always be possible. We suggest that the decision to resect should always be made if possible. Patients with a history of AGCT should always be carefully considered for surgery for other indications, as even extremely long recurrences are possible.

The inhibition roles of RAB23 gene in granulosa cell proliferation and progesterone synthesis of hen ovarian prehierarchical follicles.

1. The proliferation of granulosa cells is vital for the development and recruitment of hen ovarian prehierarchical follicles (PF). The RAB23 protein is a member of the Rab family, belonging to the GTPase family. This study studied the regulatory roles of the RAB23 gene in PF.2. The expression of RAB23 was significantly increased in granulosa cells (GC) during PF growth and was highest in GC at 6-8 mm diameter (p < 0.05). The RAB23 protein was mainly expressed in the GC, oocytes (OC) as well as somatic cells (SC) of the PF.3. The mRNA expression of FSHR, CCND1,CYP11A1, StAR and HSD3B1 was significantly increased in the siRNA RAB23 group (p < 0.05). Additionally, protein expression of FSHR, CCND1, CYP11A1, HSD3B1 was significantly increased (p < 0.05) after GC were transfected with RAB23-specific siRNA. Protein expression of StAR in the siRNA RAB23 group was numerically higher than that in the positive control (PC) and negative control (NC) groups. The GC proliferation rate and progesterone synthesis of the prehierarchical follicles in hen ovaries were markedly increased in vitro (p < 0.05).4.This study revealed that RAB23 might play an inhibitory role in GC proliferation and progesterone synthesis during the prehierarchical follicles development in vitro.

Transcriptome Dynamics and Cell Dialogs Between Oocytes and Granulosa Cells in Mouse Follicle Development.

The development and maturation of follicles is a sophisticated and multistage process. The dynamic gene expression of oocytes and their surrounding somatic cells and the dialogs between these cells are critical to this process. In this study, we accurately classified the oocyte and follicle development into nine stages and profiled the gene expression of mouse oocytes and their surrounding granulosa cells and cumulus cells. The clustering of the transcriptomes showed the trajectories of two distinct development courses of oocytes and their surrounding somatic cells. Gene expression changes precipitously increased at Type 4 stage and drastically dropped afterward within both oocytes and granulosa cells. Moreover, the number of differentially expressed genes between oocytes and granulosa cells dramatically increased at Type 4 stage, most of which persistently passed on to the later stages. Strikingly, cell communications within and between oocytes and granulosa cells became active from Type 4 stage onward. Cell dialogs connected oocytes and granulosa cells in both unidirectional and bidirectional manners. TGFB2/3, TGFBR2/3, INHBA/B, and ACVR1/1B/2B of TGF-ß signaling pathway functioned in the follicle development. NOTCH signaling pathway regulated the development of granulosa cells. Additionally, many maternally DNA methylation- or H3K27me3-imprinted genes remained active in granulosa cells but silent in oocytes during oogenesis. Collectively, Type 4 stage is the key turning point when significant transcription changes diverge the fate of oocytes and granulosa cells, and the cell dialogs become active to assure follicle development. These findings shed new insights on the transcriptome dynamics and cell dialogs facilitating the development and maturation of oocytes and follicles.

Fat Mass and Obesity-Associated Protein Regulates Granulosa Cell Aging by Targeting Matrix Metalloproteinase-2 Gene Via an N6-Methyladenosine-YT521-B Homology Domain Family Member 2-Dependent Pathway in Aged Mice.

In this study, we aimed to investigate the molecular mechanisms of RNA N6-methyladenosine (m6A) modification and how its associated proteins affect granulosa cell aging. A granulosa cell senescence model was constructed to detect the differences in total RNA m6A modification levels and the expression of related enzymes. Changes in downstream molecular expression and the effects on the cellular senescence phenotype were explored by repeatedly knocking down and overexpressing the key genes fat mass and obesity-associated protein (FTO), YT521-B homology domain family member 2 (YTHDF2), and matrix metalloproteinase-2 (MMP2). There was an increased total RNA m6A modification and decreased expression of the demethylase FTO and target gene MMP2 in senescent granulosa cells. FTO and MMP2 knockdown promoted granulosa cell senescence, whereas FTO and MMP2 overexpression retarded it. YTHDF2 and FTO can bind to the messenger RNA of MMP2. The extracellular signal-regulated kinase (ERK) pathway, which is downstream of MMP2, retarded the process of granulosa cell senescence through ERK activators. In granulosa cells, FTO can regulate the expression of MMP2 in an m6A-YTHDF2-dependent manner, influencing the activation status of the ERK pathway and contributing to the aging process of granulosa cells.