A novel perspective on di-hexyl phthalate (2-ethylhexyl)-induced reproductive toxicity in females: Lipopolysaccharide synergizes with mono-2-ethylhexyl ester to cause inflammatory apoptosis rather than autophagy in ovarian granulosa cells

Di-hexyl phthalate (2-ethylhexyl) (DEHP) has been confirmed to cause female reproductive toxicity in humans and model animals by affecting the survival of ovarian granulosa cells (GCs), but the interrelationships between DEHP's on autophagy, apoptosis, and inflammation in GCs are not clear. Our previous study demonstrated that DEHP exposure resulted in the disturbance of intestinal flora associated with serum LPS release, which in turn led to impaired ovarian function. LPS has also been shown to determine cell fate by modulating cellular autophagy, apoptosis, and inflammation. Therefore, this study investigated the role and link between LPS and autophagy, apoptosis, and inflammation of GCs in DEHP-induced ovarian injury. Here, we constructed an in vivo injury model by continuous gavage of 0-1500 mg/kg of DEHP in female mice for 30 days and an in vitro injury model by treatment of human ovarian granulosa cells (KGN) cells with mono-2- ethylhexyl ester (MEHP, an active metabolite of DEHP in vivo). In addition, the expression of relevant pathway molecules was detected by immunohistochemistry, immunofluorescence, qRT-PCR, and Western blotting after the addition of the autophagy inhibitor 3-methyladenine (3-MA), the apoptosis inhibitor Z-VAD- FMK and the NF-κB inhibitor BAY11-7082. The current study found that autophagy and apoptosis were significantly activated in GCs of DEHP-induced atretic follicles in vivo and found that MEHP-induced KGN cells autophagy and apoptosis were independent and potentially cytotoxic of each other in vitro. Further studies confirmed that DEHP exposure resulted in LPS release from the intestinal tract and entering the ovary, thereby participating in DEHP-induced inflammation of GCs. In addition, we found that exogenous LPS synergized with MEHP could activate the NF-κB signaling pathway to induce inflammation and apoptosis of GCs in a relatively prolonged exposure condition. Meanwhile, inhibition of inflammatory activation could rescue apoptosis and estrogen secretion function of GCs induced by MEHP combined with LPS. These results indicated that the increased LPS influenced by DEHP might cooperate with MEHP to induce inflammatory apoptosis of GCs, an important cause of ovarian injury in mice.

Cellular senescence of granulosa cells in the pathogenesis of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age, but its pathology has not been fully characterized and the optimal treatment strategy remains unclear. Cellular senescence is a permanent state of cell-cycle arrest that can be induced by multiple stresses. Senescent cells contribute to the pathogenesis of various diseases, owing to an alteration in secretory profile, termed 'senescence-associated secretory phenotype' (SASP), including with respect to pro-inflammatory cytokines. Senolytics, a class of drugs that selectively eliminate senescent cells, are now being used clinically, and a combination of dasatinib and quercetin (DQ) has been extensively used as a senolytic. We aimed to investigate whether cellular senescence is involved in the pathology of PCOS and whether DQ treatment has beneficial effects in patients with PCOS. We obtained ovaries from patients with or without PCOS, and established a mouse model of PCOS by injecting dehydroepiandrosterone. The expression of the senescence markers p16INK4a, p21, p53, γH2AX, and senescence-associated β-galactosidase and the SASP-related factor interleukin-6 was significantly higher in the ovaries of patients with PCOS and PCOS mice than in controls. To evaluate the effects of hyperandrogenism and DQ on cellular senescence in vitro, we stimulated cultured human granulosa cells (GCs) with testosterone and treated them with DQ. The expression of markers of senescence and a SASP-related factor was increased by testosterone, and DQ reduced this increase. DQ reduced the expression of markers of senescence and a SASP-related factor in the ovaries of PCOS mice and improved their morphology. These results indicate that cellular senescence occurs in PCOS. Hyperandrogenism causes cellular senescence in GCs in PCOS, and senolytic treatment reduces the accumulation of senescent GCs and improves ovarian morphology under hyperandrogenism. Thus, DQ might represent a novel therapy for PCOS.

Differential expression of follicular fluid exosomal microRNA in women with diminished ovarian reserve

PURPOSE

Decreased ovarian reserve function is mainly characterized by female endocrine disorders and fertility decline. Follicular fluid (FF) exosomal microRNAs (miRNAs) have been shown to regulate the function of granulosa cells (GCs). The present study explored differentially expressed miRNAs (DEmiRNAs) in patients with diminished ovarian reserve (DOR).

METHODS

FF was collected from 12 DOR patients and 12 healthy controls. DEmiRNAs between the two groups were identified and analyzed using high-throughput sequencing technology and validated by real-time quantitative PCR (RT-qPCR).

RESULTS

A total of 592 DEmiRNAs were identified using high-throughput miRNA sequencing, of which 213 were significantly upregulated and 379 were significantly downregulated. The sequencing results were further validated by RT-qPCR. These DEmiRNA target genes were mainly involved in the cancer pathway, phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, regulation of actin cytoskeleton signaling pathway, and biological processes related to protein binding, nucleoplasm, cytoplasm, and cell membrane.

CONCLUSION

FF exosomal miRNAs are significantly differentially expressed in DOR patients versus non-DOR patients, underscoring their crucial role in regulating the pathogenesis of DOR.

Vitamin D3 reduces the symptoms of ovarian hyperstimulation syndrome in mice and inhibits the release of granulosa cell angiogenic factor through pentraxin 3

It has been reported that the effective inhibition of vascular endothelial growth factor (VEGF) can prevent the progression of ovarian hyperstimulation syndrome (OHSS). The present study aimed to investigate the mechanism underlying the effect of vitamin D3 (VD3) on OHSS in mouse models and granulosa cells. The effects of VD3 administration (16 and 24 IU) on ovarian permeability were determined using Evans blue. In addition, ovarian pathology, corpus luteum count, inflammatory responses, and hormone and VEGFA levels were assessed using pathological sections and ELISA. Molecular docking predicted that pentraxin 3 (PTX3) could be a potential target of VD3, and therefore, the effects of human chorionic gonadotropin (hCG) and VD3 as well as PTX3 overexpression on the production and secretion of VEGFA in granulosa cells were also investigated using western blotting and immunofluorescence. Twenty-four IU VD3 significantly reversed the increase in ovarian weight and permeability in mice with OHSS. Additionally, VD3 diminished congestion and the number of corpus luteum in the ovaries and reduced the secretion levels of inflammatory factors and those of estrogen and progesterone. Notably, VD3 downregulated VEGFA and CD31 in ovarian tissues, while the expression levels of PTX3 varied among different groups. Furthermore, VD3 restored the hCG-induced enhanced VEGFA and PTX3 expression levels in granulosa cells, whereas PTX3 overexpression abrogated the VD3-mediated inhibition of VEGFA production and secretion. The present study demonstrated that VD3 could inhibit the release of VEGFA through PTX3, thus supporting the beneficial effects of VD3 administration on ameliorating OHSS symptoms.

WNT4 promotes macrophage polarization via granulosa cell M-CSF and reduces granulosa cell apoptosis in endometriosis

BACKGROUND

WNT4 gene polymorphism are common in endometriosis and may functionally link estrogen and estrogen receptor signaling. Previous study confirmed estrogen and estrogen receptor signaling recruit macrophage to promote the pathogenesis of endometriosis. To investigate the effect of WNT4 in endometriosis involved in macrophage polarization and whether WNT4 could reduce the apoptosis of granulosa cells.

METHODS

An observational study consisting of 8 cases of women with endometriosis (diagnosed by surgery and histology) and 22 mice of endometriosis animal model was conducted. Granulosa cells were isolated from 16 patients with endometriosis and co-cultured with macrophage under WNT4 treatment using TUNEL assay, quantitative reverse transcription PCR, flow cytometry and ELISA analysis. 22 mice of endometriosis animal model confirmed the WNT4 treatment effects using histology and immunohistochemistry, Western blot and flow cytometry.

RESULTS

We observed that the apoptotic proportion of granulosa cells was significantly decreased and M2 macrophage was significantly increased after WNT4 treatment during the granulosa cell and macrophage co-culture system. To reveal the underlying mechanism for this, we conducted a series of experiments and found that high expression of granulosa cell M-CSF led to the M2 polarization of macrophages. The animal model also suggested that the anti-apoptotic effect of WNT4 on granulosa cells were conducted by the M2 polarized macrophage.

CONCLUSIONS

WNT4 could reduce granulosa cell apoptosis and improve ovarian reserve by promoting macrophage polarization in endometriosis. M-CSF secreted by granulosa cell after WNT4 treatment was the main mediator of macrophage polarization.

Serum granulosa cell-derived TNF-α promotes inflammation and apoptosis of renal tubular cells and PCOS-related kidney injury through NF-κB signaling

Polycystic ovary syndrome (PCOS) is a disorder with endocrinal and metabolic problems in reproductive aged women. Evidence shows that PCOS is in a high prone trend to develop kidney diseases. In this study, we investigated the mediators responsible for PCOS-related kidney injury. We found that tumor necrosis factor (TNF-α) levels were significantly increased in serum and primary cultured granulosa cells (GCs) from PCOS patients. Serum TNF-α levels were positively correlated with serum testosterone and luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratio, suggesting its positive role in the severity of PCOS. Serum TNF-α levels were also positively correlated with the levels of urinary KapU, LamU, α1-MU and β2-MU, the markers for renal tubular cell-derived proteinuria. We established a PCOS mouse model by resection of the right kidney, followed by daily administration of dihydrotestosterone (DHT, 27.5 μg, i.p.) from D7 for 90 days. We found that TNF-α levels were significantly increased in the ovary and serum of the mice, accompanied by increased renal tubular cell apoptosis, inflammation and fibrosis in kidneys. Furthermore, the receptor of TNF-α, tumor necrosis factor receptor 1 (TNFR1), was significantly upregulated in renal tubular cells. We treated human ovarian granulosa-like tumor cells (KGN) with DHT (1 μg/ml) in vitro, the conditioned medium derived from the granulosa cell culture greatly accelerated apoptotic injury in human proximal tubular epithelial cells (HKC-8), which was blocked after knockdown of TNF-α in KGN cells. Furthermore, knockdown of TNFR1 in renal tubular epithelial cells greatly ameliorated cell injury induced by granulosa cell-derived conditioned medium. These results suggest that serum TNF-α plays a key role in mediating inflammation and apoptosis in renal tubular cells associated with PCOS-related kidney injury.

The function of exosomes in ovarian granulosa cells

Granulosa cells (GCs), as the basic components of ovarian tissue, play an indispensable role in maintaining normal ovarian functions such as hormone synthesis and ovulation. The abnormality of GCs often leads to ovarian endocrine disorders, which exert a negative effect on life quality and life expectancy. However, the pathogenesis and treatment of diseases are still poorly understood. Exosomes contain regulatory molecules and can transmit biological information in cell interaction. The role of exosomes in GCs has been studied extensively. This review summarizes the regulatory function of exosomes in GCs, as well as their participation in etiopathogenesis and their promising application in treatment when it comes to ovarian endocrine diseases, which can help us better understand ovarian diseases from the perspective of GCs.

FABP5 inhibitor SBFI-26 regulates FOXM1 expression and Wnt signaling pathway in ovarian granulosa cell of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most prevalent endocrinopathy among females of reproductive age. Due to its unclear etiopathogenesis, it is of vital significance to take a deeper understanding of molecular mechanisms underlying PCOS. Quantitative real-time PCR (RT-qPCR) and western blot were applied for detection of gene expression and protein expression individually. Cell Counting Kit-8 (CCK-8) and colony formation assays were used for the evaluation of cell proliferation while Caspase-3/9 activity was measured for the assessment of cell apoptosis. We found that FOXM1 was overexpressed in ovarian granulosa cell (OGC) of patients with PCOS. Functionally, upregulation of FOXM1 promotes the proliferative ability of PCOS-OGC cells. As for mechanism, FOXM1 exerts its functions in PCOS-OGC cell through activation of the Wnt signaling pathway. More importantly, a novel FABP5 inhibitor, SBFI-26, was verified to downregulate the expression of FOXM1 to impede the proliferation of PCOS-OGC cells. In addition, SBFI-26 inactivates Wnt signaling pathway in PCOS-OGC cells. FABP5 inhibitor SBFI-26 regulates FOXM1 expression and Wnt signaling pathway in OGC of patients with PCOS, which might provide a new perspective into PCOS treatment.

Endocrine Disrupting Chemicals in Polycystic Ovary Syndrome: The Relevant Role of the Theca and Granulosa Cells in the Pathogenesis of the Ovarian Dysfunction

Polycystic ovary syndrome (PCOS) is the most common heterogeneous endocrine disorder among women of reproductive age. The pathogenesis of PCOS remains elusive; however, there is evidence suggesting the potential contribution of genetic interactions or predispositions combined with environmental factors. Among these, endocrine disrupting chemicals (EDCs) have been proposed to potentially contribute to the etiology of PCOS. Granulosa and theca cells are known to cooperate to maintain ovarian function, and any disturbance can lead to endocrine disorders, such as PCOS. This article provides a review of the recent knowledge on PCOS pathophysiology, the role of granulosa and theca cells in PCOS pathogenesis, and the evidence linking exposure to EDCs with reproductive disorders such as PCOS.

The Role of Inactivated NF-κB in Premature Ovarian Failure

Premature ovarian failure (POF) is defined as deployment of amenorrhea due to the cessation of ovarian function in a woman younger than 40 years old. The pathologic mechanism of POF is not yet well understood, although genetic aberrations, autoimmune damage, and environmental factors have been identified. The current study demonstrated that NF-κB inactivation is closely associated with the development of POF based on the data from literature and cyclophosphamide (Cytoxan)-induced POF mouse model. In the successfully established NF-κB-inactivated mouse model, the results showed the reduced expression of nuclear p65 and the increased expression of IκBα in ovarian granulosa cells; the reduced numbers of antral follicles; the reduction of Ki-67/proliferating cell nuclear antigen-labeled cell proliferation and enhanced Fas/FasL-dependent apoptosis in granulosa cells; the reduced level of E2 and anti-Müllerian hormone; the decreased expression of follicle-stimulating hormone receptor and cytochrome P450 family 19 subfamily A member 1 (CYP19A1) in granulosa cells, which was reversed in the context of blocking NF-κB signaling with BAY 11-7082; and the decreased expressions of glucose-regulated protein 78 (GRP78), activating transcription factor 6, protein kinase R-like endoplasmic reticulum kinase, and inositol-requiring enzyme 1 in granulosa cells. Dual-luciferase reporter assay demonstrated that p50 stimulated the transcription of GRP78, and NF-κB affected the expression of follicle-stimulating hormone receptor and promoted granulosa cell proliferation through GRP78-mediated endoplasmic reticulum stress. Taken together, these data indicate, for the first time, that the inactivation of NF-κB signaling plays an important role in POF.

FTO protects human granulosa cells from chemotherapy-induced cytotoxicity

BACKGROUND

Premature ovarian failure (POF) is a serious problem for young women who receive chemotherapy, and its pathophysiological basis is the dysfunction of granulosa cells. According to previous reports, menstrual-derived stem cells (MenSCs) can restore ovarian function and folliculogenesis in mice with chemotherapy-induced POF. Fat mass- and obesity-associated (FTO) was reported to be associated with oocyte development and maturation. FTO was decreased in POF and may be a biomarker for the occurrence of POF. Knockdown of FTO in granulosa cells promoted cell apoptosis and inhibited proliferation. But the relationship between FTO and ovarian repair was still unclear. This study was aimed at investigating the FTO expression level and the role of FTO in the MenSCs recovering the function of injured granulosa cells.

METHOD

First, cisplatin was used to establish a granulosa cell injury model. Then, the MenSCs and injured granulosa cell coculture model and POF mouse model were established in this study to explore the role of FTO. Furthermore, gain- and loss-of-function studies, small interfering RNA transfection, and meclofenamic acid (MA), a highly selective inhibitor of FTO, studies were also conducted to clarify the regulatory mechanism of FTO in granulosa cells.

RESULTS

MenSCs coculture could improve the function of injured granulosa cells by increasing the expression of FTO. MenSCs transplantation restored the expression of FTO in the ovaries of POF mice. Overexpression of FTO restored the injured cell proliferation and decreased apoptosis by regulating the expression of BNIP3. Down-regulation of FTO got the opposite results.

CONCLUSIONS

In the treatment of MenSCs, FTO has a protective effect, which could improve the viability of granulosa cells after cisplatin treatment by decreasing the expression of BNIP3. Meanwhile, FTO may provide new insight into therapeutic targets for the chemotherapy-induced POF.

Melatonin protects against ovarian damage by inhibiting autophagy in granulosa cells in rats

OBJECTIVES

This study sought to further verify the protective mechanism of Melatonin (MT) against ovarian damage through animal model experiments and to lay a theoretical and experimental foundation for exploring new approaches for ovarian damage treatment.

METHOD

The wet weight and ovarian index of rat ovaries were weighted, and the morphology of ovarian tissues and the number of follicles in the pathological sections of collected ovarian tissues were recorded. And the serum sex hormone levels, the key proteins of the autophagy pathway (PI3K, AKT, mTOR, LC3II, LC3I, and Agt5) in rat ovarian tissues, as well as the viability and mortality of ovarian granulosa cells in each group were measured by ELISA, western blotting, CCK8 kit and LDH kit, respectively.

RESULTS

The results showed that MT increased ovarian weight and improved the ovarian index in ovarian damage rats. Also, MT could improve autophagy-induced ovarian tissue injury, increase the number of primordial follicles, primary follicles, and sinus follicles, and decrease the number of atretic follicles. Furthermore, MT upregulated serum AMH, INH-B, and E2 levels downregulated serum FSH and LH levels in ovarian damage rats and activated the PI3K/AKT/mTOR signaling pathway. Besides, MT inhibited autophagic apoptosis of ovarian granulosa cells and repressed the expression of key proteins in the autophagic pathway and reduced the expression levels of Agt5 and LC3II/I.

CONCLUSIONS

MT inhibits granulosa cell autophagy by activating the PI3K/Akt/mTOR signaling pathway, thereby exerting a protective effect against ovarian damage.

Interleukin-4 activates the PI3K/AKT signaling to promote apoptosis and inhibit the proliferation of granulosa cells

The inflammatory microenvironment has been demonstrated to play a role in folliculogenesis, ovulation and premature ovarian failure (POF), as well as infertility. In this study, we aimed to explore the role of inflammation in modulating growth and apoptosis in granulosa cells (GCs), the main components of ovarian follicles. ELISA was used to analyze the levels of inflammatory factors (IL-1β, IL-4, IL-6 and IL-10) in follicular fluid samples and GCs derived from POF patients and healthy normal individuals. CCK-8, flow cytometry and TUNEL assays were used to assess the effect of IL-4 on GC growth and apoptosis. Western blotting was used to examine the effect of IL-4 on the activation of PI3K/Akt, Erk1/2 and Jnk signaling. The results showed that IL-4, IL-1β and IL-6 levels were increased in follicular fluid samples and GCs derived from POF patients compared with those from healthy individuals. GC growth was weakened when cells were treated with IL-4, while apoptosis was increased. In addition, IL-4 increased the level of p-Akt/Akt in GCs. In addition, LY294002, an inhibitor of PI3K, abolished the effect of IL-4 by inhibiting GC growth and promoting apoptosis. In summary, this study demonstrated that IL-4 levels were increased in POF samples and that IL-4 could inhibit GC growth and induce GC apoptosis by activating PI3K/Akt signaling.

Acupuncture regulates the autophagy of ovarian granulosa cells in polycystic ovarian syndrome ovulation disorder by inhibiting the PI3K/AKT/mTOR pathway through LncMEG3

The main features of polycystic ovary syndrome (PCOS) are abnormal follicular development and ovulation dysfunction, which are caused by the excessive autophagy of ovarian granulosa cells. Acupuncture has been shown to improve ovulation dysfunction and abnormal follicular development in PCOS patients, but its mechanism is unclear. This study hypothesized that the beneficial effects of acupuncture are the result of LncMEG3-mediated effects on the PI3K/AKT/mTOR pathway. Acupuncture (CV-4, RN-3, CV-6, SP-6 and EX-CA 1) was used to treat a rat model of polycystic ovary syndrome. Hematoxylin-eosin staining was used to observe ovarian morphology and enzyme-linked immunosorbent assay, western blotting, immunohistochemistry and real-time PCR were used to detect LH, E2, FSH, T, AMH, LncMEG3, PI3K, AKT, mTOR, P62 and LC3II/I expression. The ovarian morphology of 90% of the rats in the acupuncture treatment group was significantly improved after 11 consecutive days of therapy. Acupuncture also resulted in a significant decrease in serum LH, FSH, T and AMH levels and a significant increase in E2 level (P<0.01). LncMEG3, PI3K, AKT, mTOR, P62 and LC3II/I expression was decreased in ovarian granulosa cells after acupuncture compared with PCOS and lentiviral Intervention Group (P<0.05), while the expression of follicle stimulating hormone receptor was increased (P<0.05). These results indicate that acupuncture can down-regulate the expression of LncMEG3 and thereby inhibit the PI3K/AKT/mTOR pathway, reducing granulosa cell autophagy and normalizing their proliferation. These factors ultimately remedy abnormal follicular development. These findings suggest that acupuncture has clinical potential as a safe treatment for PCOS ovulatory dysfunction.

microRNA-194 is increased in polycystic ovary syndrome granulosa cell and induce KGN cells apoptosis by direct targeting heparin-binding EGF-like growth factor

BACKGROUND

Polycystic ovary syndrome (PCOS) is an endocrine-related follicular developmental disorder that affects 50 %-70 % of reproductive-aged women diagnosed with ovulation-related infertility. Abnormal proliferation and apoptosis of granulosa cells (GCs) are thought to be the critical factors leading to abnormal maturation of follicles. It has been shown that microRNAs (miRNAs) exert a significant influence in the pathogenesis of PCOS; however, the relationship between miRNA, PCOS, and GC apoptosis is not entirely understood.

METHODS

To clarify the effect of miR-194 in PCOS, CCK-8, Ki67 staining, AO/EB, and flow cytometry assays were used to assess cell growth, proliferation, and apoptosis in KGN cells, which were artificially stimulated to overexpress miR-194. Luciferase reporter assays and rescue experiments were used to elucidate the mechanism underlying miR-194 in PCOS.

RESULTS

miR-194 expression was significantly up-regulated in rat models of PCOS and the ovarian GCs of PCOS patients. miR-194 suppression promoted KGN cell growth and proliferation. miR-194 overexpression also induced cell apoptosis, while miR-194 downregulation had an opposite effect. Furthermore, up-regulating heparin-binding EGF-like growth factor (HB-EGF) expression rescued the pro-apoptotic effects of miR-194 upregulation on KGN cells.

CONCLUSIONS

miR-194 is increased in PCOS granulosa cell and may function as a novel biomarker and therapeutic target for KGN cells via HB-EGF regulation.

Circ_0043532 regulates miR-182/SGK3 axis to promote granulosa cell progression in polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disease in women at childbearing age. Several circular RNAs (circRNAs) have been demonstrated to be involved in PCOS. In this study, we aimed to explore the function and mechanism of circ_0043532 in PCOS.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine the expression of circ_0043532, miR-182 and serum/glucocorticoid regulated kinase family member 3 (SGK3). Cell proliferation was assessed by 5-ethynyl-2'-deoxyuridine (EdU) assay and 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Flow cytometry analysis was employed to evaluate cell cycle and cell apoptosis. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to verify the association between miR-182 and SGK3. Western blot assay was carried out to determine the protein level of SGK3.

RESULTS

Circ_0043532 was markedly elevated in PCOS granulosa cells (GCs) and KGN cells. Silencing of circ_0043532 suppressed cell proliferation and cell cycle process and promoted cell apoptosis in PCOS GCs and KGN cells. For mechanistic analysis, circ_0043532 was identified as a sponge of miR-182 and SGK3 was confirmed to be a target gene of miR-182. Inhibition of miR-182 rescued the impacts of circ_0043532 interference on PCOS GCs and KGN cell progression. Moreover, miR-182 overexpression suppressed cell proliferation and cell cycle process and promoted cell apoptosis in PCOS GCs and KGN cells by targeting SGK3.

CONCLUSION

Deficiency of circ_0043532 suppressed cell proliferation and induced cell cycle arrest and cell apoptosis in PCOS by modulation of miR-182/SGK3 axis.

Altered redox status may contribute to aberrant folliculogenesis and poor reproductive outcomes in women with polycystic ovary syndrome

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are often infertile and opt for artificial reproductive techniques (ART) to conceive. Disrupted pro-/antioxidant balance in oocyte microenvironment may contribute towards sub-optimal oocyte/embryo quality and poor ART outcome in them.

METHODS

Activities/levels of redox markers and their transcript expression were investigated in follicular fluid and granulosa cells respectively, in women with PCOS (n = 71) and controls (n = 50) undergoing in vitro fertilization (IVF). Correlation analysis of redox markers and IVF parameters was performed.

RESULTS

Activities of superoxide dismutase, glutathione reductase, glutathione peroxidase, and paraoxonase1 were significantly lower in follicular fluid of PCOS women than in controls. Levels of lipid peroxidation, oxidative protein modification, and oxidized glutathione were higher, whereas those of total antioxidant capacity, total thiols, and reduced glutathione were lower in follicular fluid of PCOS women than in controls. Further, comparison of redox markers based on insulin resistance and BMI status of study participants showed similar trends, indicating that PCOS pathophysiology is a significant contributor to oxidative stress irrespective of insulin resistance and BMI. Transcript levels of antioxidant enzymes were lower in granulosa cells from PCOS women than in controls, and they accorded with their activities in follicular fluid. Moreover, few redox markers showed significant correlations with oocyte/embryo quality and pregnancy outcome.

CONCLUSION

Our data indicates disrupted redox homeostasis in follicular environment in PCOS which may negatively influence oocyte/embryo quality. Further, granulosa cells may play crucial role in maintaining follicular redox homeostasis. Glutathione system and paraoxonase1 could be explored further as surrogates for IVF prognosis/outcome.

Granulosa cells apoptosis and follicular fluid hormones: comparison of progestin-primed ovarian stimulation versus GnRH antagonist protocols

OBJECTIVE

To explore the effect of progestin-primed ovarian stimulation protocol (PPOS) on mural granulosa cells (GCs) apoptosis and hormonal profiles in follicular fluid (FF) and efficacy over GnRH antagonist (GnRH-A) protocols.

METHODS

We performed a prospective cohort study from June through August 2017 at a tertiary teaching hospital. 63 Patients meeting our criteria were recruited in this prospective study voluntarily and stratified to PPOS or GnRH-A group randomly. Mural GCs and FF were collected during oocyte retrieval. Apoptosis of GCs was assessed using the Annexin V-affinity assay by flow cytometry and hormonal profiles in FF were measured using electrochemiluminescence.

RESULTS

A total of 63 women were assessed for eligibility, with 25 cases in PPOS group and 38 in GnRH-A group. Difference of early stage apoptosis rate, late stage apoptosis rate, and total apoptosis rate did not reach statistical significance between groups. Meanwhile, concentrations of hormones in FF were comparable in two groups. No statistically significant differences were observed in number of oocytes retrieved, mature oocyte rate, fertilization rate, and top-quality embryos rate. No patients experienced premature LH surge in both groups during the study.

CONCLUSION

Compared to GnRH antagonist protocol, PPOS had comparable laboratory outcomes, GCs apoptosis rate and hormonal profiles in FF. PPOS is an effective and safe alternative option to provide controlled ovarian hyperstimulation (COH).

The role of FDX1 in granulosa cell of Polycystic ovary syndrome (PCOS)

BACKGROUND

To explore the development mechanism of PCOS and Transcriptomics was applied to seek the key gene.

METHODS

Transcriptomics marked by UID (unique identifier) technique of granulosa cell in PCOS and control women was carried out and key gene was picked up. Then the key gene in granulosa cell was measured by RT-PCR. Two PCOS models modeling with Letrozole and Testosterone Propionate were implemented and the key gene in granulosa cell of ovary was measured by immunohistochemistry to verify the relation with PCOS.

RESULTS

GO-enrich of transcriptomics concentrated in domain steroid metabolism and domain mitochondria. Different genes were sought from coexisting in both domain steroid metabolism and domain mitochondria. Finally, five different genes including CYP11A1、CYB5R1、STAR、FDX1 and AMACR were obtained. RT-PCR was implemented to furtherly verify the downregulating mRNA of FDX1 in PCOS, which showed the consistent outcome with the transcriptomics. Level of FDX1 protein in granulosa cell of antral follicle in two PCOS models was measured and decreased.

CONCLUSIONS

FDX1 was related with steroid metabolism and mitochondrial and may participate in the development of PCOS.

TRDMT1 participates in the DNA damage repair of granulosa cells in premature ovarian failure

The molecular mechanisms underlying premature ovarian failure, which seriously impacts the physical and psychological health of patients, are not fully understood. Here, we present the role of TRDMT1 in reactive oxygen species-induced granulosa cells death, which is considered an important cause of premature ovarian failure. We found that reactive oxygen species were increased in a H2O2 dose-dependent manner and accompanied by the nuclear shuttling of TRDMT1, increased DNA damage and increased apoptosis of granulosa cells. In addition, reactive oxygen species-induced granulosa cells apoptosis could be prevented by the antioxidant N-acetylcysteine or overexpression of TRDMT1. Furthermore, DNA repair following reactive oxygen species induction was severely impaired/enhanced in TRDMT1 mutants, which exhibited reduced/increased RNA m5C methylation activity. Altogether, our results reveal a novel role of TRDMT1 in the regulation of premature ovarian failure through the repair of reactive oxygen species-triggered DNA damage in granulosa cells and provide an improved understanding of the mechanisms underlying granulosa cells apoptosis, which could potentially be useful for future clinical treatments of premature ovarian failure.

Treg deficiency-mediated TH 1 response causes human premature ovarian insufficiency through apoptosis and steroidogenesis dysfunction of granulosa cells

Immune dysregulation has long been proposed as a component of premature ovarian insufficiency (POI), but the underlying mediators and mechanisms remain largely unknown. Here we showed that patients with POI had augmented T helper 1 (TH 1) responses and regulatory T (Treg ) cell deficiency in both the periphery and the ovary compared to the control women. The increased ratio of TH 1:Treg cells was strongly correlated with the severity of POI. In mouse models of POI, the increased infiltration of TH 1 cells in the ovary resulted in follicle atresia and ovarian insufficiency, which could be prevented and reversed by Treg cells. Importantly, interferon (IFN) -γ and tumor necrosis factor (TNF) -α cooperatively promoted the apoptosis of granulosa cells and suppressed their steroidogenesis by modulating CTGF and CYP19A1. We have thus revealed a previously unrecognized Treg cell deficiency-mediated TH 1 response in the pathogenesis of POI, which should have implications for therapeutic interventions in patients with POI.

Persistent follicular granulosa cell senescence and apoptosis induced by methotrexate leading to oocyte dysfunction and aberrant embryo development

Evidence from clinical cases indicates an association between the low success rate of in vitro fertilization (IVF) and ovarian injury due to previous methotrexate (MTX) administration. Therefore, it is necessary to develop and propose reasonable clinical drug guidelines to improve the quality of oocytes and the development of embryos before pregnancy. In this study, we established a mouse model with previous MTX exposure to validate the effects of MTX on reproductive function in female mice. We observed that MTX administration could result in a decrease in the success rate of fertilization and an aberrant embryonic development in both natural fertilization and IVF, even after completion of five to six ovulation cycles after MTX withdrawal. Further research revealed senescence and apoptosis of follicular granulosa cells (GCs), accompanied by arrested follicle development and aberrant estradiol and anti‐Mullerian hormone levels. Supportive evidence indicated that MTX administration induced senescence and apoptosis of human GCs in vitro, and the effects were consistent with the high levels of p21, p53, and oxidative stress. We further demonstrated that folic acid (FA) could improve oocyte function and embryonic development in vivo and in vitro by protecting GCs against apoptosis and senescence. Based on these findings, we propose the implementation of extended intervals between MTX exposure and conception or IVF and recommend FA as a special dietary supplement during this interval period; however, prospective inquiry in humans is necessary to further understand the relationship between MTX and FA recovery.

miR-130b-3p is high-expressed in polycystic ovarian syndrome and promotes granulosa cell proliferation by targeting SMAD4

BACKGROUND

Being one of the most prevalent metabolic and endocrine disorders, Polycystic Ovary Syndrome (PCOS) has been proven to be associated with microRNA-130b-3p (miR-130b-3p). However, the exact role played by miR-130b-3p in the pathogenesis and progression of PCOS remains unknown. Thus, this article is focused on elucidating the function of miR-130b-3p in the pathogenesis of PCOS.

METHODS

The expression levels of miR-130b-3p and SMAD4 in tissues and cells responsible for the development of PCOS were determined by RT-qPCR and western blot. A miR-130b-3p mimic/inhibitor or si-SMAD4 were transfected into KGN cells. The cell viability was detected by CCK-8 and EDU methods. The activity of caspase-3 was measured by caspase-3 analysis. Subsequently, apoptosis and the cell cycle were measured via flow cytometry. The correlation between SMAD4 and miR-130b-3p was confirmed using an RNA pull-down assay and a dual luciferase reporter system assay.

RESULTS

MiR-130b-3p was upregulated in the KGN cells and ovarian granulosa cells (GCs) of PCOS patients. It was found that miR-130b-3p overexpression or SMAD4 silencing can promote KGN cell proliferation and positive EDU rates, induce S phase arrest, inhibit apoptosis and caspase-3 activity. On the other hand, miR-130b-3p inhibitors reduce KGN cell proliferation, inhibit apoptosis and reverse the effect of si-SMAD4.

CONCLUSION

MiR-130b-3p directly interacts with SMAD4 to induce KGN cell proliferation, inhibit apoptosis, suggesting that miR-130b-3p expression is positively correlated with the development of PCOS. This may serve as new evidence for the abnormal proliferation of GCs in PCOS.

Inhibition of sestrin 1 alleviates polycystic ovary syndrome by decreasing autophagy

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age, accounting for 50-70% of anovulatory infertility cases. However, the etiology of PCOS at the molecular level remains unclear. Here, bioinformatics analysis was performed to identify differentially expressed genes (DEGs) between adipose tissue of PCOS patients and matched tissues from non-hyperandrogenic women. RT-qPCR, western blot, cell counting kit-8 (CCK-8), EdU (5-Ethynyl-2'-deoxyuridine) staining, LC3 staining, ROS (reactive oxygen species) detection, and apoptosis assays were conducted to explore the effects of sestrin 1 on KGN human granulosa-like tumor cells. Bioinformatics analysis indicated that DEGs in adipose tissue from PCOS patients were enriched in the p53 signaling pathway. Moreover, sestrin 1 was identified as a major target of the p53 gene. Downregulation of sestrin 1 inhibited proliferation of KGN cells by inhibiting autophagy. Additionally, sestrin 1 downregulation increased ROS generation and promoted apoptosis in KGN cells. By contrast, overexpression of sestrin 1 increased cell viability by increasing autophagy in KGN cells. Together, these results suggest that downregulation of sestrin 1 may be a potential novel treatment strategy for PCOS.

The Effect of Astaxanthin and Metformin on Oxidative Stress in Granulosa Cells of BALB C Mouse Model of Polycystic Ovary Syndrome

Reactive oxygen species (ROS), involved in the pathogenesis of the polycystic ovary syndrome (PCOS), play a key role in the onset of apoptosis in follicles and granulosa cells (GCs). We aimed to investigate the antioxidant effects of AST and metformin separately and in combination on GCs using a PCOS mouse model. Forty-eight prepubertal female BALB C mice aged 25-30 days and weighing 12-14 g were studied. The PCOS model was created by subcutaneous injection of the dehydroepiandrosterone (DHEA) hormone in 8 mice of BALB C for 20 consecutive days. Apoptosis and the amount of ROS were evaluated in GCs of the ovaries via flow cytometry. The activity of AKT protein was measured by western blot, and the viability of GCs was investigated using spectrophotometry. Ovarian tissue sections were prepared, stained with H&E, and the morphology of the sections was examined. Statistical analysis was performed by SPSS v22.0 software using one-way ANOVA. We found that AST administration leads to a significant reduction in oxidative stress (P<0.01) and consequently a significant decrease in the rate of apoptosis (P<0.01). While the expression of AKT in the AST group revealed a significant increase (P<0.05), it decreased in the metformin group. However, it was still significantly higher than the control and PCOS groups. Ovulation was confirmed in both metformin and AST groups. Further studies are warranted to prove the efficacy of AST and to introduce it as a complementary therapeutic agent in PCOS.

Polystyrene microplastics lead to pyroptosis and apoptosis of ovarian granulosa cells via NLRP3/Caspase-1 signaling pathway in rats

Microplastics (MPs) considered as a new persistent environmental pollutant could enter into the circulatory system and result in decrease of sperm quantity and quality in mice. However, the effects of Polystyrene MPs (PS MPs) on the ovary and its mechanism in rats remained unclear. In this present study, thirty-two healthy female Wistar rats were exposed to different concentrations of 0.5 µm PS MPs dispersed in deionized water for 90 days. Using hematoxylin-eosin (HE) staining, the number of growing follicles was decreased compared to the control group. In addition, the activity of glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) were decreased while the expression level of malondialdehyde (MDA) was increased in ovary tissue. Confirmed by immunohistochemistry, the integrated optical density of NLRP3 and Cleaved-Caspase-1 had been elevated by 13.9 and 14 in granulosa cells in the 1.5 mg/kg/d group. Furthermore, compared to the control group, the level of AMH had been decreased by 23.3 pg/ml while IL-1β and IL-18 had been increased by 32 and 18.5 pg/ml in the 1.5 mg/kg/d group using the enzyme-linked immune sorbent assay (ELISA). Besides, the apoptosis of granulosa cells was elevated measured by terminal deoxyribonucleotide transferase-mediated nick end labeling (TUNEL) staining and flow cytometry. Moreover, western blot assays showed that the expressions of NLRP3/Caspase-1 signaling pathway related factors and Cleaved-Caspase-3 were increased. These results demonstrated that PS MPs could induce pyroptosis and apoptosis of ovarian granulosa cells via the NLRP3/Caspase-1 signaling pathway maybe triggered by oxidative stress. The present study suggested that exposure to microplastics had adverse effects on ovary and could be a potential risk factor for female infertility, which provided new insights into the toxicity of MPs on female reproduction.

Zearalenone Induces Apoptosis and Cytoprotective Autophagy in Chicken Granulosa Cells by PI3K-AKT-mTOR and MAPK Signaling Pathways

Zearalenone (ZEA) is a nonsteroidal estrogenic mycotoxin found in several food commodities worldwide. ZEA causes reproductive disorders, genotoxicity, and testicular toxicity in animals. However, little is known about the functions of apoptosis and autophagy after exposure to ZEA in granulosa cells. This study investigated the effects of ZEA on chicken granulosa cells. The results show that ZEA at different doses significantly inhibited the growth of chicken granulosa cells by inducing apoptosis. ZEA treatment up-regulated Bax and downregulated Bcl-2 expression, promoted cytochrome c release into the cytosol, and triggered mitochondria-mediated apoptosis. Consequently, caspase-9 and downstream effector caspase-3 were activated, resulting in chicken granulosa cells apoptosis. ZEA treatment also upregulated LC3-II and Beclin-1 expression, suggesting that ZEA induced a high level of autophagy. Pretreatment with chloroquine (an autophagy inhibitor) and rapamycin (an autophagy inducer) increased and decreased the rate of apoptosis, respectively, in contrast with other ZEA-treated groups. Autophagy delayed apoptosis in the ZEA-treated cells. Therefore, autophagy may prevent cells from undergoing apoptosis by reducing ZEA-induced cytotoxicity. In addition, our results further show that the autophagy was stimulated by ZEA through PI3K-AKT-mTOR and MAPK signaling pathways in chicken granulosa cells.

New Anti-Müllerian Hormone Target Genes Involved in Granulosa Cell Survival in Women With Polycystic Ovary Syndrome

PURPOSE

A protective effect of anti-Müllerian hormone (AMH) on follicle atresia was recently demonstrated using long-term treatments, but this effect has never been supported by mechanistic studies. This work aimed to gain an insight into the mechanism of action of AMH on follicle atresia and on how this could account for the increased follicle pool observed in women with polycystic ovary syndrome (PCOS).

METHODS

In vivo and in vitro experiments were performed to study the effects of AMH on follicle atresia and on the proliferation and apoptosis of granulosa cells (GCs). RNA-sequencing was carried out to identify new AMH target genes in GCs. The expression of some of these genes in GCs from control and PCOS women was compared using microfluidic real time quantitative RT-PCR.

RESULTS

A short-term AMH treatment prevented follicle atresia in prepubertal mice. Consistent with this result, AMH inhibited apoptosis and promoted proliferation of different models of GCs. Moreover, integrative biology analyses of 965 AMH target genes identified in 1 of these GC models, confirmed that AMH had initiated a gene expression program favoring cell survival and proliferation. Finally, on 43 genes selected among the most up- and down-regulated AMH targets, 8 were up-regulated in GCs isolated from PCOS women, of which 5 are involved in cell survival.

MAIN CONCLUSIONS

Our results provide for the first time cellular and molecular evidence that AMH protects follicles from atresia by controlling GC survival and suggest that AMH could participate in the increased follicle pool of PCOS patients.

Induction of aryl hydrocarbon receptor in granulosa cells by endoplasmic reticulum stress contributes to pathology of polycystic ovary syndrome

Recent studies have uncovered the critical role of aryl hydrocarbon receptor (AHR) in various diseases, including obesity and cancer progression, independent of its previously identified role as a receptor for endocrine-disrupting chemicals (EDCs). We previously showed that endoplasmic reticulum (ER) stress, a newly recognized local factor in the follicular microenvironment, is activated in granulosa cells from patients with polycystic ovary syndrome (PCOS) and a mouse model of the disease. By affecting diverse functions of granulosa cells, ER stress contributes to PCOS pathology. We hypothesized that expression of AHR and activation of its downstream signaling were upregulated by ER stress in granulosa cells, irrespective of the presence of EDCs, thereby promoting PCOS pathogenesis. In this study, we found that AHR, AHR nuclear translocator (ARNT), and AHR target gene cytochrome P450 1B1 (CYP1B1) were upregulated in the granulosa cells of PCOS patients and model mice. We examined CYP1B1 as a representative AHR target gene. AHR and ARNT were upregulated by ER stress in human granulosa-lutein cells (GLCs), resulting in an increase in the expression and activity of CYP1B1. Administration of the AHR antagonist CH223191 to PCOS mice restored estrous cycling and decreased the number of atretic antral follicles, concomitant with downregulation of AHR and CYP1B1 in granulosa cells. Taken together, our findings indicate that AHR activated by ER stress in the follicular microenvironment contributes to PCOS pathology, and that AHR represents a novel therapeutic target for PCOS.

Humanin regulates oxidative stress in the ovaries of polycystic ovary syndrome patients via the Keap1/Nrf2 pathway

Polycystic ovary syndrome (PCOS) is the most common endocrinological pathology among women of reproductive age, whereas the pathogenesis is still not fully understood. Systemic and ovarian oxidative stress (OS) imbalance is a pivotal feature of PCOS. Humanin, a mitochondria-derived peptide, has been reported to function as an antioxidant in cardiomyocytes, pancreatic beta cells and other cells, but how this function is regulated remains unclear. In this study, we investigated whether humanin expression differs in the granulosa cells (GCs) of PCOS patients versus controls, and whether humanin alleviates OS in PCOS ovaries. Sixteen PCOS patients and 28 age- and BMI-matched controls undergoing IVF were recruited, and their serum, follicular fluid and GCs were collected for humanin analysis. Dehydroepiandrosterone-induced rat PCOS models, and vitamin K3-induced OS COV434 cell lines were applied to investigate the mechanism. Humanin expression was significantly down-regulated in the ovaries of PCOS patients relative to those of non-PCOS patients. Exogenous humanin supplementation significantly attenuated body weight gain, ovarian morphological abnormalities, endocrinological disorders and ovarian and systemic OS in PCOS rat models. Our study further demonstrated that this attenuation effect was involved in the modulation of the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor-erythroid 2-related factor 2 (Nrf2) signalling pathway. In summary, this study reported for the first time that decreased expression of humanin in the GCs was associated with oxidative imbalance in PCOS. Humanin alleviates OS in ovarian GCs of PCOS patients via modulation of the Keap1/Nrf2 signalling pathway.

Polystyrene microplastics cause granulosa cells apoptosis and fibrosis in ovary through oxidative stress in rats

Microplastics (MPs) are receiving increased attention as a harmful environmental pollutant. Studies have investigated that MPs have reproductive toxicity, but the mechanism is little known. Here, we aimed to investigate the effects of polystyrene microplastics (PS-MPs) on ovary in rats and the underlying molecular mechanisms. in vivo, thirty-two female Wistar rats were exposed to 0.5 μm PS-MPs at different concentrations (0, 0.015, 0.15 and 1.5 mg/d) for 90 days. And then, all animals were sacrificed, ovaries and blood were collected for testing. in vitro, granulosa cells (GCs) were separated from rat ovary and treated with 0、1、5、25 μg/mL PS-MPs and reactive oxygen species (ROS) inhibitor N-Acetyl-l-cysteine (NAC) respectively. Our results showed that PS-MPs could enter into GCs and result in the reducing of growing follicles number. And the Enzyme-linked immunosorbent assay (ELISA) manifested that PS-MPs could obviously decrease the level of anti-Müllerian hormone (AMH). In addition, PS-MPs induced oxidative stress, apoptosis of GCs and ovary fibrosis evidenced by assay kits, flow cytometry, immunohistochemistry, Masson's trichrome and Sirius red staining. Moreover, the western blot assay manifested that PS-MPs exposure significantly increased the expression levels of Wnt/β-Catenin signaling pathways-related proteins (Wnt, β-catenin, p-β-catenin) and the main fibrosis markers (transforming growth factor-β (TGF-β), fibronectin, α-smooth muscle actin (α-SMA). Additionally, the expression levels of Wnt and p-β-catenin, apoptosis of GCs decreased after NAC treatment. In summary, polystyrene microplastics cause fibrosis via Wnt/β-Catenin signaling pathway activation and granulosa cells apoptosis of ovary through oxidative stress in rats, both of which ultimately resulted in decrease of ovarian reserve capacity.

The effects of chronic lead exposure on the ovaries of female juvenile Japanese quails (Coturnix japonica): Developmental delay, histopathological alterations, hormone release disruption and gene expression disorder

Lead (Pb) is well-recognized for its great hazards to human and wildlife health. It has negative influences on multiple organs and systems of birds. Especially, lead exposure caused adverse impacts on bird reproduction. In this study, one week old female Japanese quails were randomly allocated into four groups and each group was respectively fed with 0, 50 ppm, 500 ppm and 1000 ppm Pb in drinking water for 36 days to determine the effects of chronic lead exposure on ovarian development and function. The results showed that Pb did accumulate in the ovary and ovarian development was delayed by high dose lead exposure (500 ppm and 1000 ppm). Moreover, high Pb dosage induced ovarian histopathological damages characterized by granulosa cells disorganization, follicle atresia and interstitial cell degeneration. Meanwhile, the concentration of estradiol (E2) was significantly decreased and mRNA levels of genes involved with ovarian steroidogenesis were significantly down-regulated by high concentration Pb. In addition, Pb exposure caused increasing cell apoptosis and significant changes of the expression of genes involved with cell death in the ovary. High dose Pb exposure also inhibited thyroid hormone release and disrupted ovarian thyroid deiodination apart from causing thyroid histopathological injury such as follicular deformation and atrophy. The study indicated that Pb might cause ovarian malfunction by inducing ovary and thyroid microstructural damages, thyroid hormone and estrogen release inhibition and ovarian steroidogenesis disruption.

Core clock gene Bmal1 deprivation impairs steroidogenesis in mice luteinized follicle cells

Luteinization is the event of corpus luteum formation, a way of follicle cells transformation and a process of steroidogenesis alteration. As the core clock gene, Bmal1 was involved in the regulation of ovulation process and luteal function afterwards. Till now, the underlying roles of luteinization played by Bmal1 remain unknown. To explore the unique role of Bmal1 in luteal steroidogenesis and its underlying pathway, we investigated the luteal hormone synthesis profile in Bmal1 knockout female mice. We found that luteal hormone synthesis was notably impaired, and phosphorylation of PI3K/NfκB pathway was significantly activated. Then, the results were verified in in vitro cultured cells, including isolated Bmal1 interference granulosa cells (GCs) and theca cells (TCs), respectively. Hormones levels of supernatant culture media and mRNA expressions of steroidogenesis-associated genes (star, Hsd3β2, cyp19a1 in GCs, Lhcgr, star, Hsd3β2, cyp17a1 in TCs) were mutually decreased, while the phosphorylation of PI3K/NfκB was promoted during in vitro luteinization. After PI3K specific-inhibitor LY294002 intervention, mRNA expressions of Lhcgr and Hsd3β2 were partially rescued in Bmal1 interference TCs, together with significantly increased androstenedione and T synthesis. Further exploration in TCs demonstrated BMAL1 interacted directly but negatively with NfκB p65 (RelA), a subunit which was supposed as a mediator in Bmal1-governed PI3K signaling regulation. Taken together, we verified the novel role of Bmal1 in luteal steroidogenesis, achieving by negative interplay with RelA-mediated PI3K/NfκB pathway.

lnc-MAP3K13-7:1 Inhibits Ovarian GC Proliferation in PCOS via DNMT1 Downregulation-Mediated CDKN1A Promoter Hypomethylation

Polycystic ovary syndrome (PCOS) is an endocrine-related disease and global cause of infertility that is associated with abnormal folliculogenesis. Inhibited granulosa cell (GC) proliferation is recognized as a key factor that underlies aberrant follicle maturation. Many epigenetic landscape modifications have been characterized in PCOS patients. However, the epigenetic regulation pathways in follicular dysplasia are not completely understood. In this study, we reported a novel mechanism of DNA hypomethylation induced by long non-coding RNAs (lncRNAs) and its function in cell cycle progression. We observed that lnc-MAP3K13-7:1 was highly expressed in GCs from patients with PCOS, with concomitant global DNA hypomethylation, decreased DNA methyltransferase 1 (DNMT1) expression, and increased cyclin-dependent kinase inhibitor 1A (CDKN1A, p21) expression. In KGN cells, lnc-MAP3K13-7:1 overexpression resulted in cell cycle arrest in the G₀/G₁ phase, as well as the molecular inhibition and genetic silencing of DNMT1. Mechanistically, lnc-MAP3K13-7:1 inhibited DNMT1 expression by acting as a protein-binding scaffold and inducing ubiquitin-mediated DNMT1 protein degradation. Moreover, DNMT1-dependent CDKN1A promoter hypomethylation increased CDKN1A transcription, resulting in attenuated GC growth. Our work uncovered a novel and essential mechanism through which lnc-MAP3K13-7:1-dependent DNMT1 inhibition regulates CDKN1A/p21 expression and inhibits GC proliferation.

In Search of New Therapeutics-Molecular Aspects of the PCOS Pathophysiology: Genetics, Hormones, Metabolism and Beyond

In a healthy female reproductive system, a subtle hormonal and metabolic dance leads to repetitive cyclic changes in the ovaries and uterus, which make an effective ovulation and potential implantation of an embryo possible. However, that is not so in the case of polycystic ovary syndrome (PCOS), in which case the central mechanism responsible for entraining hormonal and metabolic rhythms during the menstrual cycle is notably disrupted. In this review we provide a detailed description of the possible scenario of PCOS pathogenesis. We begin from the analysis of how a set of genetic disorders related to PCOS leads to particular malfunctions at a molecular level (e.g., increased enzyme activities of cytochrome P450 (CYP) type 17A1 (17α-hydroxylase), 3β-HSD type II and CYP type 11A1 (side-chain cleavage enzyme) in theca cells, or changes in the expression of aquaporins in granulosa cells) and discuss further cellular- and tissue-level consequences (e.g., anovulation, elevated levels of the advanced glycation end products in ovaries), which in turn lead to the observed subsequent systemic symptoms. Since gene-editing therapy is currently out of reach, herein special emphasis is placed on discussing what kinds of drug targets and which potentially active substances seem promising for an effective medication, acting on the primary causes of PCOS on a molecular level.

The upregulation of 11β-HSD1 in ovarian granulosa cells by cortisol and interleukin-1β in polycystic ovary syndrome

Our previous study have demonstrated the elevated cortisol concentration in the follicular fluid (FF) contributed to the insulin resistance of the granulosa cells (GCs) in PCOS, but the complicated cortisol generation mechanisms are still unknown. 11β-hydroxysteroid type 1(11β-HSD1) mainly functions as reductase in intact cells, converting cortisone to cortisol. Cortisol and IL-1β are known to induce 11β-HSD1 in number of tissues, but few results were obtained in ovarian GCs In this study, FF and GCs from PCOS and non-PCOS patients were collected to study the interaction of cortisol and IL-1β in 11β-HSD1 expression. The ELISA and qRT-PCR revealed that the cortisol and IL-1β concentration in FF and 11β-HSD1 abundance in GCs were elevated in PCOS patients. By using cultured GCs in vitro, we demonstrated that both cortisol and IL-1β could stimulate 11β-HSD1 expression. The induction of 11β-HSD1 by IL-1β was further inducted by cortisol, whereas the induction of IL-1β and IL-6 expression by IL-1β was completely inhibited by cortisol. In conclusion, cortisol and IL-1β preformed a synergistically upregulation of 11β-HSD1 expression in GCs, contributing to the accumulation of cortisol in FF of PCOS patients. This may lead to the metabolic disorders of the ovary.

Acrylamide impairs ovarian function by promoting apoptosis and affecting reproductive hormone release, steroidogenesis and autophagy-related genes: An in vivo study

Acrylamide (ACR) toxicity is quite common due to its widespread use in industry and due to the Maillard browning reaction that occurs in foods containing high concentrations of hydrocarbons subjected to high temperatures. This study aimed to elucidate the female reproductive toxicity of ACR in vivo. Fifty-day-old Wistar-Albino female rats were treated with different dosages of ACR (2.5, 10, and 50 mg/kg/day). After treatment, the animals were sacrificed, and serum and ovary samples were collected for histological examination, hormone analysis, TUNEL analysis, and RT-PCR studies. We found that ACR acts by significantly reducing ovarian weight and serum progesterone and estradiol concentrations. In addition, ACR treatment led to pyknotic, heterochromatic characteristics and nuclear fragmentation, as evidenced by hematoxylin staining. The TUNEL assay revealed that granulosa cells were affected after the oral administration of ACR, leading to the apoptosis of follicles at different stages of growth. Compared with the control condition, high doses of ACR (50 mg/kg/day) significantly induced the overexpression of INSL3, CYP17a, IGF1, ESR1, ESR2, ATG5, ATG12 and LC3 in the ovary. Moreover, LC3 mRNA levels significantly increased with increasing doses of ACR (2.5, 10 and 50 mg/kg/day), suggesting that ACR treatment induced autophagy. In conclusion, ACR induced ovarian dysfunction by affecting steroid hormone release, increasing apoptosis and mRNA levels of autophagy-related genes. The eventual correlation between apoptotic granulosa cell death and autophagy needs to be further explored.

Chlorogenic acid rescues zearalenone induced injury to mouse ovarian granulosa cells

Zearalenone (ZEA), a toxic substance produced by Fusarium fungi, accumulated in cereals grain and animal feed, causes injury to humans and animals. ZEA can induce obvious reproductive toxicity with the ovarian granulosa cells (GCs) as the main target. However, the study on exploring the protective compounds against ZEA-induced mouse primary ovarian GCs damage remains less. In the current study, the protective effect of 20 compounds derived from traditional Chinese medicines (TCMs) on the injury of mouse GCs caused by ZEA were evaluated using MTT assay and the cell morphology. Our results showed that chlorogenic acid (250, 500, and 1000 μg/mL) significantly suppress ZEA-induced GCs death. Western blot analysis suggested chlorogenic acid could rescue the up-regulated apoptosis of GCs induced by ZEA via attenuating the protein expression of cleaved caspase-3, the ratio of Bax/Bcl-2 and cleaved-PARP. Our results provide strong evidence that chlorogenic acid warrants further optimization for more potent and safer compounds for against the ZEA lead toxicity to humans and animals.

Downregulation of Lnc-OC1 attenuates the pathogenesis of polycystic ovary syndrome

Long non-coding RNAs (lncRNAs) play a vital role in the progression of many human diseases. The aim of this study is to explore the relationship between lncRNA-ovarian cancer associated 1 (Lnc-OC1) and PCOS. In this study, we found that Lnc-OC1 was significantly higher in PCOS granulosa cells (GCs) compared to non-PCOS GCs. Lnc-OC1 knockdown inhibited cell viability and promoted cell apoptosis, expression of aromatase mRNA and production of estradiol in KGN cells. In PCOS mice, Lnc-OC1 promoted the serum insulin release, production of angiogenesis-related factors and IκBα phosphorylation, which could be partially restored by Lnc-OC1 shRNA. These results suggest that Lnc-OC1 plays an important part in the pathogenesis of PCOS.

NORFA, long intergenic noncoding RNA, maintains sow fertility by inhibiting granulosa cell death

Long intergenic non-coding RNAs (lincRNAs) have been proved to be involved in regulating female reproduction. However, to what extent lincRNAs are involved in ovarian functions and fertility is incompletely understood. Here we show that a lincRNA, NORFA is involved in granulosa cell apoptosis, follicular atresia and sow fertility. We found that NORFA was down-regulated during follicular atresia, and inhibited granulosa cell apoptosis. NORFA directly interacted with miR-126 and thereby preventing it from binding to TGFBR2 3'-UTR. miR-126 enhanced granulosa cell apoptosis by attenuating NORFA-induced TGF-β signaling pathway. Importantly, a breed-specific 19-bp duplication was detected in NORFA promoter, which proved association with sow fertility through enhancing transcription activity of NORFA by recruiting transcription factor NFIX. In summary, our findings identified a candidate lincRNA for sow prolificacy, and provided insights into the mechanism of follicular atresia and female fertility.

Bisphenol S Impaired Human Granulosa Cell Steroidogenesis in Vitro

Bisphenol S (BPS) is a structural analog of the endocrine disruptor bisphenol A (BPA); it is the main BPA replacement in the plastics industry. Previous studies have shown that BPA and BPS exhibit similar effects on reproduction in fish and rodent species. BPS reportedly alters steroidogenesis in bovine granulosa cells. Luteinised granulosa cells collected from 59 women who were undergoing an in vitro fertilization procedure were cultured for 48 h in the presence or absence of BPS (10 nM, 100 nM, 1 µM, 10 µM or 50 µM). BPS exposure was investigated by assessing follicular fluids from these 59 women for their BPS content. Culture medium, cells, total messenger RNA (mRNA) and total protein extracted from the luteinised granulosa cells were examined for oestradiol and progesterone secretion, cellular proliferation, viability, gene expression, steroidogenic enzyme expression and cell signaling. BPS was measured in follicular fluids using mass spectrometry. Exposure of granulosa cells to 10 or 50 µM BPS for 48 h induced a 16% (p = 0.0059) and 64% (p < 0.0001) decrease, respectively, in progesterone secretion; 50 µM BPS decreased oestradiol secretion by 46% (p < 0.0001). Ten µM BPS also tended to reduce CYP11A1 protein expression by 37% (p = 0.0947) without affecting HSD3B1 and CYP19A1 expression. Fifty µM BPS increased ERRγ expression. Environmental levels of BPS (nanomolar range) did not induce changes in steroidogenesis in human granulosa cells. The effects of BPS were observed after only 48 h of BPS exposure. These acute effects might be similar to chronic effects of physiological BPS levels.

Disruption of 17β-estradiol secretion by persistent organic pollutants present in human follicular fluid is dependent on the potential of ovarian granulosa tumor cell lines to metabolize estrogen

Endocrine-disrupting chemicals (EDCs), such as perfluorooctanoate, perfluorooctane sulfonate, 2,2-dichlorodiphenyldichloroethylene, hexachlorobenzene, and polychlorinated biphenyl 153 are persistent pollutants that are found in human follicular fluid (FF). These compounds may affect endocrine function, disrupt steroid secretion by granulosa cells, and play a role in granulosa cell tumor (GCT) development. GCTs demonstrate endocrine activity, expressing aromatase and secreting 17β-estradiol (E2). We aimed to determine the effects of a mixture of EDCs, similar to that found in human FF, on human granulosa tumor cell lines representing the juvenile (JGCT) and adult (AGCT) forms (COV434 and KGN cells, respectively). We found that all the individual compounds and mixtures tested altered granulosa tumor cell function by disrupting E2 secretion. In KGN cells, which possess significantly higher basal aromatase gene expression, and therefore secrete more E2 than JGCT cells, EDC mixtures activated estrogen receptors (ERs) and G protein-coupled receptor-30 signaling, thereby stimulating E2 secretion, without affecting aromatase expression. By contrast, in COV434 cells, which demonstrate higher CYP1A1 expression, a key mediator of estrogen metabolism, than KGN cells, EDC mixtures reduced E2 secretion in parallel with increases in the 2-hydroxyestrogen 1/E2 ratio and CYP1A1 expression, implying an upregulation of E2 metabolism. These results indicate that the EDC mixture present in FF disrupts E2 secretion in JGCT and AGCT cells according to the estrogen metabolic potential of the cell type, involving both classical and non-classical ER pathways.

Effects of vitamin D on steroidogenesis, reactive oxygen species production, and enzymatic antioxidant defense in human granulosa cells of normal and polycystic ovaries

Polycystic ovary syndrome (PCOS) is accompanied with many disturbances in hormone synthesis and antioxidant defense. Previous reports have indicated that Vitamin D (vit.D) affects gene expression and have roles in normal follicular development. Therefore, we investigated the effects of vit.D on steroidogenesis, apoptosis, reactive oxygen species (ROS) production, and antioxidant defenses of human normal granulosa cells (N-GCs) and granulosa cells from polycystic ovaries (PCO-GCs). Ovarian GCs were obtained during oocyte retrieval procedure from 120 women with PCOS and from 100 healthy women who referred to Shiraz Fertility Center. The isolated GCs were cultured in the presence or absence of vit.D (100 nM), for 48 h. Concentration of sex steroids was measured by ELISA. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) expression and activities were assessed by q-PCR and photometric methods, respectively. The amount of ROS production was estimated using chemiluminescence and fluorescence methods. Cell viability and apoptosis were detected by Annexin-V/propidium iodide detection kit. Basal estrone and progesterone secretion by N-GCs was significantly higher than that of PCO-GCs. Vit.D significantly increased aromatase and 3β-hydroxysteroid dehydrogenase activity in N-GCs and PCO-GCs. Basal expression and activity of GPx, in PCO-GCs were significantly lower than those of N-GCs. Treatment with vit.D significantly increased genes expression and enzyme activities in both groups. Basal ROS in PCO-GCs was markedly greater than that of N-GCs, which was attenuated by vit.D treatment. Cell apoptosis was directly correlated with ROS levels. We conclude that vit.D improved N-GCs and PCO-GCs functions through affecting steroidogenesis and enzymatic antioxidant defense. Under vit.D treatment, PCO-GCs could act more similar to N-GCs.

LncRNA HCP5 promotes cell proliferation and inhibits apoptosis via miR-27a-3p/IGF-1 axis in human granulosa-like tumor cell line KGN

This study aimed to reveal the potential roles of long non-coding RNA HCP5 (lncRNA HCP5) and its potential molecular mechanism in polycystic ovarian syndrome (PCOS). The human granulosa-like tumor cell line KGN was used for assessing the effects of HCP5 in the proliferation and apoptosis of granulosa cells (GCs). The results showed that downregulation of HCP5 suppressed cell proliferation through arresting cell cycle progression at G1 phase, and induced the apoptosis via activating mitochondrial pathway, while overexpression of HCP5 played the opposite effects in KGN cells. We predicted and confirmed miR-27a-3p was a directly target to HCP5 and it could directly bind with insulin-like growth factor-1 (IGF-1). Next, we performed gain- and loss-of-functions approaches by transfecting miR-27a-3p inhibitor into HCP5 knocking down cells and transfecting miR-27a-3p mimics into HCP5 overexpressing cells. The results demonstrated that downregulation and upregulation of miR-27a-3p could block the effects on the proliferation and apoptosis mediated by silencing and overexpressing HCP5 in KGN cells. Additionally, miR-27a-3p inhibitor remarkably reversed the IGF-1 decrease regulated by knocking down HCP5 and miR-27a-3p mimics inhibited the IGF-1 increase modulated by overexpressing HCP5 in KGN cells. Furthermore, we observed that the promoted cell vitality and reduced apoptosis mediated by enforced expression of HCP5 could be alleviated when the KGN cells transfected with IGF-1 siRNA. Our findings indicate that HCP5 might be a potential regulatory factor for development of PCOS through regulating the miR-27a-3p/IGF-1 axis.

MicroRNA-9119 regulates cell viability of granulosa cells in polycystic ovarian syndrome via mediating Dicer expression

Polycystic ovary syndrome (PCOS) is a hormonal disorder common among women of reproductive age. Although much is understood concerning the pathology of PCOS, further investigation into the influence of microribonucleic acids (miRNAs) on the proliferation of ovarian granulosa cells (GCs) is needed. This study investigated the role of specific miRNAs in ovarian dysfunction of PCOS and its effect on the proliferation of GCs. Initially, miRNA profiling was performed on the ovarian cortexes of 15 rats in which PCOS had been induced and 15 rats without PCOS (non-PCOS). This mechanical study was performed on ovarian GCs extracted from human chorionic gonadotrophin (hCG)-induced rats. Insulin was used to treat GCs to establish the PCOS cell model. Increased Equus caballus mir-9119 expression was observed and confirmed in the insulin-induced model of PCOS in GCs (GC-PCOS) as well as in the hCG-induced rats when compared to non-PCOS rats and cells. Observation and confirmation were carried out through both miRNA array and quantitative PCR. In contrast, downregulation of the nuclear factor kappa B (NFκB) p65 was observed in the PCOS cell model. Additionally, annexin V, FITC, and propidium iodide flow cytometry showed overexpression of miR-9119-induced apoptosis. In this study, we revealed that miR-9119 inhibition regulates p65 expression levels in insulin-treated GCs by binding to the 3'-untranslated of p65. Additionally, regulation of p65 expression was positively correlated with the expression of the double-stranded RNA endoribonuclease DICER. Moreover, RNA silencing/overexpression of p65 affected the functional role of miR-9119. In conclusion, GCs of PCOS, the expression of miR-9119, and targeted NFκB/p65-DICER axis are upregulated in order to maintain cell viability and prevent apoptosis, thereby promoting Anti-Müllerian hormone production in GCs. This study may provide a new understanding of the mechanism of GC dysfunction.

Granulosa-Lutein Cell Sirtuin Gene Expression Profiles Differ between Normal Donors and Infertile Women

Sirtuins are a family of deacetylases that modify structural proteins, metabolic enzymes, and histones to change cellular protein localization and function. In mammals, there are seven sirtuins involved in processes like oxidative stress or metabolic homeostasis associated with aging, degeneration or cancer. We studied gene expression of sirtuins by qRT-PCR in human mural granulosa-lutein cells (hGL) from IVF patients in different infertility diagnostic groups and in oocyte donors (OD; control group). Study 1: sirtuins genes’ expression levels and correlations with age and IVF parameters in women with no ovarian factor. We found significantly higher expression levels of SIRT1, SIRT2 and SIRT5 in patients ≥40 years old than in OD and in women between 27 and 39 years old with tubal or male factor, and no ovarian factor (NOF). Only SIRT2, SIRT5 and SIRT7 expression correlated with age. Study 2: sirtuin genes’ expression in women poor responders (PR), endometriosis (EM) and polycystic ovarian syndrome. Compared to NOF controls, we found higher SIRT2 gene expression in all diagnostic groups while SIRT3, SIRT5, SIRT6 and SIRT7 expression were higher only in PR. Related to clinical parameters SIRT1, SIRT6 and SIRT7 correlate positively with FSH and LH doses administered in EM patients. The number of mature oocytes retrieved in PR is positively correlated with the expression levels of SIRT3, SIRT4 and SIRT5. These data suggest that cellular physiopathology in PR’s follicle may be associated with cumulative DNA damage, indicating that further studies are necessary.

Acupuncture Reduces Apoptosis of Granulosa Cells in Rats with Premature Ovarian Failure Via Restoring the PI3K/Akt Signaling Pathway

Acupuncture is widely recognized as an effective therapy for premature ovarian failure (POF) in clinical, but information about its potential mechanisms is rarely explored. To investigate the mechanism, fifty SD female rats were randomly divided into normal group, POF group, POF+estradiol-valerate group (abbreviated as estradiol group), and POF+acupuncture group (abbreviated as acupuncture group). The estrous cycle of the rats was tracked by vaginal smears. Their ovaries morphology was observed by hematoxylin-eosin staining. The apoptotic level of granulosa cells was detected by in situ TUNEL fluorescence staining assay. Serum follicle-stimulating hormone (FSH) and estrogen (E2) levels were measured by enzyme-linked-immunosorbent-assay (ELISA). Protein and gene expression of PI3K, Akt, bcl-2, and bax were detected by Western blotting and qPCR. In the acupuncture and estradiol groups, compared with the POF group as controls, the apoptosis number of granulosa cells was significantly decreased (p < 0.05). FSH levels were decreased, while E2 levels were increased (p > 0.05). The gene and protein expression levels of PI3K, Akt, and bcl-2 were increased, while the expression levels of bax were decreased (p < 0.05), and the protein expression level of p-Akt increased. There was no significant difference between the acupuncture group and the estradiol group (p > 0.05). Acupuncture was able to regulate hormone levels in POF rats, up-regulate PI3K/Akt signaling pathway, and reduce the apoptosis of granulosa cells. This may be one of the mechanisms of acupuncture treating premature ovarian failure.

MiR-29a regulates the proliferation, aromatase expression, and estradiol biosynthesis of human granulosa cells in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility in reproductive-aged women; however, its etiology remains poorly understood. This study aimed to reveal the role of miR-29a in PCOS. MiR-29a levels were measured in the granulosa cells (GCs) of forty-seven PCOS patients and forty-seven controls. A receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of miR-29a in non-hyperandrogenism PCOS. MiR-29a was overexpressed in KGN and COV434 cells to examine its roles in proliferation, cell-cycle progression, and steroidogenesis. MiR-29a was significantly down-regulated in PCOS patients, and associated with an increased antral follicle count. The ROC curve showed a major separation between PCOS patients and controls. MiR-29a overexpression in KGN and COV434 cells inhibited cell proliferation, arrested cell-cycle progression, and decreased aromatase expression and estradiol production. These findings suggest that miR-29a is involved in GC proliferation and steroidogenesis, providing insights into PCOS pathogenesis.

miR-15b induces premature ovarian failure in mice via inhibition of α-Klotho expression in ovarian granulosa cells

A thorough understanding of epigenetics regulatory mechanisms of premature ovarian failure (POF) is still lacking. Here, we found that cyclophosphamide induced significantly decrease in α-Klotho (Kl) expression in mouse ovarian granulosa cells (mOGCs), suggesting that cyclophosphamide inhibited Kl expression. Cyclophosphamide also significantly accelerated ageing and led to a decline in the pregnancy rate of C. elegans. We subsequently noted that the pathological condition exhibited by Kl^-/- mice was similar to that observed in cyclophosphamide-induced POF mice. Furthermore, the mOGCs in both types of mice showed significant signs of oxidative stress damage, including decreased SOD and ATP, increased ROS levels. Detailed analyses revealed that the decreased Kl expression led to the reduced expression of autophagy-related proteins in mOGCs, which resulted in decreased autophagy activity. Finally, we found that cyclophosphamide attenuated the autophagy function of mOGCs via upregulating microRNA-15b expression, which silenced the endogenous Kl mRNA expression and stimulated the activity of the downstream TGFβ1/Smad pathway. Therefore, we demonstrated that Kl was one of the key inhibitory factors in the development of POF. It elucidated the underlying epigenetic regulatory mechanism, whereby cyclophosphamide-dependent microRNA-15b inhibited Kl expression, leading to the reduced ability of mOGCs to induce autophagy and ROS scavenging, ultimately causing POF.

Altered miR-186 and miR-135a contribute to granulosa cell dysfunction by targeting ESR2: A possible role in polycystic ovary syndrome

MicroRNAs (miRNAs) are a group of negative regulators of gene expression that function at the posttranscriptional level. Dysregulation of miRNAs is involved in many pathophysiological processes, including polycystic ovary syndrome (PCOS). In this study, we first detected the expression levels of 6 candidate miRNA in granulosa cells (GCs) from 63 women with PCOS and 20 healthy controls. We found that miR-186 and miR-135a were overexpressed in GCs from PCOS patients. Subsequently, the direct targets of miR-186 and miR-135a were predicted using bioinformatics analysis and verified by luciferase assays and immunoblotting. The present study determined that miR-186 and miR-135a repressed ESR2 expression in GCs, which further inhibited CDKN1A expression, promoted GC proliferation and repressed GC apoptosis. Meanwhile, the levels of miR-186 and miR-135a in GCs were found to positively correlate with serum estradiol levels in patients with PCOS. Furthermore, estradiol treatment directly increased miR-186 and miR-135a levels in KGN and primary GCs, which provides new insight into understanding the pathophysiology of PCOS.