Resveratrol Improves Follicular Development of PCOS Rats by Regulating the Glycolytic Pathway

Hyperglycemia Inhibits Hepatic SHBG Synthesis Through the NGBR-AMPK-HNF4 Pathway in Rats with Polycystic Ovary Syndrome Induced by Letrozole in Combination with a High-Fat Diet

SCOPE

Polycystic ovary syndrome (PCOS) is closely related to non-alcoholic fatty liver disease (NAFLD), and sex hormone-binding globulin (SHBG) is a glycoprotein produced by the liver. Hepatic lipogenesis inhibits hepatic SHBG synthesis, which leads to hyperandrogenemia and ovarian dysfunction in PCOS. Therefore, this study aims to characterize the mechanism whereby liver lipogenesis inhibits SHBG synthesis.

METHODS AND RESULTS

This study establishes a rat model of PCOS complicated by NAFLD using a high-fat diet in combination with letrozole and performs transcriptomic analysis of the liver. Transcriptomic analysis of the liver shows that the expression of neurite growth inhibitor-B receptor (NgBR), hepatocyte nuclear factor 4α (HNF4α), and SHBG is low. Meantime, HepG2 cells are treated with palmitic acid (PA) to model NAFLD in vitro, which causes decreases in the expression of NgBR, HNF4α, and SHBG. However, the expression of HNF4α and SHBG is restored by treatment with the AMP-activated protein kinase (AMPK) agonist AICAR.

CONCLUSIONS

NgBR regulates the expression of HNF4α by activating the AMPK signaling pathway, thereby affecting the synthesis of SHBG in the liver. Further mechanistic studies regarding the effect of liver fat on NGBR expression are warranted.

Exploring the mechanism of clomiphene citrate to improve ovulation disorder in PCOS rats based on follicular fluid metabolomics

To examine the effects of clomiphene citrate (CC) on follicular fluid metabolites and related metabolic pathways in rats with polycystic ovary syndrome (PCOS) using non-targeted metabolomics and determine how CC treats ovulation disorder in PCOS. The Sprague Dawley rats were randomly divided into control, model, and CC groups. A PCOS model was established with letrozole. Body weight, ovarian weight, estrus cycles, serum hormone levels, and ovary histopathology of the rats were collected for further evaluation. Moreover, through ultra-performance liquid chromatography-mass spectrometry, the study of follicular fluid metabolites revealed the mechanism of action of CC. CC reduced ovarian weight and regulated estrous cycles and serum hormone levels in PCOS rats but did not affect their body weight. Moreover, the metabolomic results showed that CC adjusted 153 metabolites, among which 16 cross metabolites like testosterone, androstenedione, 17α-hydroxyprogesterone, and cholic acid were considered as potential biomarkers for CC to improve ovulation disorders in PCOS rats. Kyoto Encyclopedia of Genes and Genomes pathway enrichment also showed that the CC group mainly engaged in tryptophan metabolism and steroid hormone biosynthesis. CC can improve ovulation disorders in rats, and its mechanism is related to the regulation of the secretion of serum hormone and follicular fluid metabolites and the amelioration of multi-metabolic pathways.

Untargeted metabolomics of buffalo urine reveals hydracyrlic acid, 3-bromo-1-propanol and benzyl serine as potential estrus biomarkers

Buffalo is a silent heat animal and doesn't show prominent signs of estrous like cattle so it becomes difficult for farmers to determine the receptivity of the animal based purely on the animal behaviour. India, having a huge population size, needs to produce more milk for the population. Successful artificial insemination greatly depends on the receptivity of the animal. Hence the present study aimed to identify the changes in the metabolome of the buffalo. GC-MS based mass spectrometric analysis was deployed for the determination of estrous by differential expression of metabolites. It was found that hydracrylic acid, 3-bromo-1-propanol and benzyl serine were significantly upregulated in the estrous phase of buffalo (p.value ≤0.05, FC ≥ 2). The pathway enrichment analysis also supported the same as pathways related to amino acid metabolism and fatty acid metabolism were up regulated along with the Warburg effect which is linked to the rapid cell proliferation which might help prepare animals to meet the energy requirement during the estrous. Further analysis of the metabolic biomarkers using ROC analysis also supported these three metabolites as probable biomarkers as they were identified with AUC values of 0.7 or greater. SIGNIFICANCE: The present study focuses on the untargeted metabolomics studies of buffalo urine with special reference to the estrous phase of reproductive cycle. The estrous signals are more prominent in cattle, where animals show clear estrous signals such as mounting and discharge along with vocal signals. Buffalo is a silent heat animal and it becomes difficult for farmers to detect the estrous based on the physical and behavioral signals. Hence the present study focuses on GC-MS based untargeted metabolomics to identify differentially expressed urine metabolites. In this study, hydracrylic acid, 3-bromo-1-propanol and benzyl serine were found to be significantly upregulated in the estrous phase of buffalo (p-value ≤0.05, FC ≥ 2). Further confirmation of the metabolic biomarkers was done using Receiver operating characteristics (ROC) analysis which also supported these three metabolites as probable biomarkers as they had AUC values of 0.7 or greater. Hence, this study will be of prime importance for the people working in the area of animal metabolomics.

Molecular Mechanism of Resveratrol and Its Therapeutic Potential on Female Infertility

Resveratrol is a polyphenol present in various plant sources. Studies have reported numerous potential health benefits of resveratrol, exhibiting anti-aging, anti-inflammatory, anti-microbial, and anti-carcinogenic activity. Due to the reported effects, resveratrol is also being tested in reproductive disorders, including female infertility. Numerous cellular, animal, and even human studies were performed with a focus on the effect of resveratrol on female infertility. In this review, we reviewed some of its molecular mechanisms of action and summarized animal and human studies regarding resveratrol and female infertility, with a focus on age-related infertility, polycystic ovary syndrome, and endometriosis.

α-Ketoglutarate Improves Ovarian Reserve Function in Primary Ovarian Insufficiency by Inhibiting NLRP3-Mediated Pyroptosis of Granulosa Cells

SCOPE

Premature ovarian insufficiency (POI) is a common female infertility problem, with its pathogenesis remains unknown. The NOD-like receptor family pyrin domain-containing 3 (NLRP3)-mediated pyroptosis has been proposed as a possible mechanism in POI. This study investigates the therapeutic effect of α-ketoglutarate (AKG) on ovarian reserve function in POI rats and further explores the potential molecular mechanisms.

METHODS AND RESULTS

POI rats are caused by administration of cyclophosphamide (CTX) to determine whether AKG has a protective effect. AKG treatment increases the ovarian index, maintains both serum hormone levels and follicle number, and improves the ovarian reserve function in POI rats, as evidence by increased the level of lactate and the expression of rate-limiting enzymes of glycolysis in the ovaries, additionally reduced the expression of NLRP3, Gasdermin D (GSDMD), Caspase-1, Interleukin-18 (IL-18), and Interleukin-1 beta (IL-1β). In vitro, KGN cells are treated with LPS and nigericin to mimic pyroptosis, then treated with AKG and MCC950. AKG inhibits inflammatory and pyroptosis factors such as NLRP3, restores the glycolysis process in vitro, meanwhile inhibition of NLRP3 has the same effect.

CONCLUSION

AKG ameliorates CTX-induced POI by inhibiting NLRP3-mediated pyroptosis, which provides a new therapeutic strategy and drug target for clinical POI patients.

Expression profile analysis of LncRNAs and mRNAs in pre-receptive endometrium of women with polycystic ovary syndrome undergoing in vitro fertilization-embryo transfer

BACKGROUND

To compare the expression levels of long non-coding RNA (lncRNA) and messenger RNA (mRNA) in pre-receptive endometrium between patients with Polycystic Ovary Syndrome (PCOS)and normal ovulation undergoing in vitro fertilization-embryo transfer (IVF-ET).

METHODS

Endometrial tissues were collected with endometrial vacuum curette in pre-receptive phase (3 days after oocytes retrieval) from PCOS and control groups. LncRNAs and mRNAs of endometrium were identified via RNA sequencing and alignments. A subset of 9 differentially expressed lncRNAs and 11 mRNAs were validated by quantitative reverse transcription polymerase chain reaction(qRT-PCR)in 22 PCOS patients and 18 ovulation patients. The function of mRNAs with differential expression patterns were explored using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG).

RESULTS

We found out 687 up-regulated and 680 down-regulated mRNAs, as well as 345 up-regulated and 63 down-regulated lncRNAs in the PCOS patients in contrast to normal ovulation patients. qRT-PCR was used to detect the expression of 11 mRNAs, and validated that the expression of these 6 mRNAs CXCR4, RABL6, OPN3, SYBU, IDH1, NOP10 were significantly elevated among PCOS patients, and the expression of ZEB1 was significantly decreased. qRT-PCR was performed to detect the expression of 9 lncRNAs, and validated that the expression of these 7 lncRNAs IDH1-AS1, PCAT14, FTX, DANCR, PRKCQ-AS1, SNHG8, TPT1-AS1 were significantly enhanced among PCOS patients. Bioinformatics analysis showed that differentially expressed genes (DEGs) involved KEGG pathway were tyrosine metabolism, PI3K-Akt pathway, metabolic pathway, Jak-STAT pathway, pyruvate metabolism, protein processing in endoplasmic reticulum, oxidative phosphorylation and proteasome. The up-regulation of GO classification was involved in ATP metabolic process, oxidative phosphorylation, RNA catabolic process, and down-regulation of GO classification was response to corticosteroid, steroid hormone, and T cell activation.

CONCLUSION

Our results determined the characteristics and expression profile of endometrial lncRNAs and mRNAs in PCOS patients in pre-receptive phase, which is the day 3 after oocytes retrival. The possible pathways and related genes of endometrial receptivity disorders were found, and those lncRNAs may be developed as a predictive biomarker of endometrium in pre-receptive phase.

miRNA profiling of granulosa cell-derived exosomes reveals their role in promoting follicle development

To explore whether granulosa cell (GC)-derived exosomes (GC-Exos) and follicular fluid-derived exosomes (FF-Exos) have functional similarities in follicle development and to establish relevant experiments to validate whether GC-Exos could serve as a potential substitute for follicular fluid-derived exosomes to improve folliculogenesis. GC-Exos were characterized. MicroRNA (miRNA) profiles of exosomes from human GCs and follicular fluid were analyzed in depth. The signature was associated with folliculogenesis, such as phosphatidylinositol 3 kinases-protein kinase B signal pathway, mammalian target of rapamycin signal pathway, mitogen-activated protein kinase signal pathway, Wnt signal pathway, and cyclic adenosine monophosphate signal pathway. A total of five prominent miRNAs were found to regulate the above five signaling pathways. These miRNAs include miRNA-486-5p, miRNA-10b-5p, miRNA-100-5p, miRNA-99a-5p, and miRNA-21-5p. The exosomes from GCs and follicular fluid were investigated to explore the effect on folliculogenesis by injecting exosomes into older mice. The proportion of follicles at each stage is counted to help us understand folliculogenesis. Exosomes derived from GCs were isolated successfully. miRNA profiles demonstrated a remarkable overlap between the miRNA profiles of FF-Exos and GC-Exos. The shared miRNA signature exhibited a positive influence on follicle development and activation. Furthermore, exosomes derived from GCs and follicular fluid promoted folliculogenesis in older female mice. Exosomes derived from GCs had similar miRNA profiles and follicle-promoting functions as follicular fluid exosomes. Consequently, GC-Exos are promising for replacing FF-Exos and developing new commercial reagents to improve female fertility.

Effects of resveratrol on polycystic ovarian syndrome: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Polycystic ovarian syndrome (PCOS) is the heightened ovarian dysfunction associated with excessive androgen production, manifesting with hirsutism, abnormal menstrual cycle, and polycystic ovaries. In this systematic review and meta-analysis, the effect of resveratrol on laboratory parameters of PCOS women will be assessed.

METHODS

An electronic search via PubMed, Cochrane Library, and Scopus was performed up to February 2023 for randomized controlled trials conforming to our pre-specified outcomes. A random-effects model was utilized, with cohorts compared using mean differences.

RESULTS

Three randomized controlled trials (RCTs) were included, reporting 84 patients receiving resveratrol, and 85 patients receiving placebo. It was observed that resveratrol significantly improved prolactin levels (P = 0.02), acne scores (P = 0.008), and total cholesterol (P = 0.02). However, there were no significant improvements observed with respect to total testosterone, follicle stimulating hormone (FSH), lutenizing hormone (LH), body mass index (BMI), hirsutism scores, triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL).

CONCLUSION

As per the results of our analysis, resveratrol demonstrates mild therapeutic potential for the sufferers of PCOS, and cannot replace the current established treatment guidelines. However, further comprehensive RCTs are required in order to assess the efficacy in long-term dosing and the safety profile of the use of resveratrol.

Pyrroloquinoline quinone inhibits PCSK9-NLRP3 mediated pyroptosis of Leydig cells in obese mice

Abnormal lipid metabolism and chronic low-grade inflammation are the main traits of obesity. Especially, the molecular mechanism of concomitant deficiency in steroidogenesis-associated enzymes related to testosterone (T) synthesis of obesity dominated a decline in male fertility is still poorly understood. Here, we found that in vivo, supplementation of pyrroloquinoline quinone (PQQ) efficaciously ameliorated the abnormal lipid metabolism and testicular spermatogenic function from high-fat-diet (HFD)-induced obese mice. Moreover, the transcriptome analysis of the liver and testicular showed that PQQ supplementation not only inhibited the high expression of proprotein convertase subtilisin/Kexin type 9 (PCSK9) but also weakened the NOD-like receptor family pyrin domain containing 3 (NLRP3)-mediated pyroptosis, which both played a negative role in T synthesis of Leydig Cells (LCs). Eventually, the function and the pyroptosis of LCs cultured with palmitic acid in vitro were simultaneously benefited by suppressing the expression of NLRP3 or PCSK9 respectively, as well the parallel effects of PQQ were affirmed. Collectively, our data revealed that PQQ supplementation is a feasible approach to protect T synthesis from PCSK9-NLRP3 crosstalk-induced LCs' pyroptosis in obese men.

Caffeic acid's role in mitigating polycystic ovary syndrome by countering apoptosis and ER stress triggered by oxidative stress

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder that affects women of reproductive age, characterized by androgen-induced oxidative stress leading to several metabolic disorders. In this study, we investigated the potential therapeutic effect of caffeic acid on PCOS and its underlying molecular mechanism. We used a human ovarian granulosa cell line (KGN cells) induced by hydrogen peroxide (H2O2) to examine how caffeic acid influences the protein expression of oxidative stress-induced apoptosis-related markers. Our results indicate that caffeic acid significantly inhibits intracellular reactive oxygen species (ROS) generation and safeguards KGN cells against oxidative stress. For the in vivo aspect of our study, female Sprague-Dawley (SD) rats were utilized to induce the PCOS model using dehydroepiandrosterone (DHEA). Caffeic acid was then administered to the rats for a duration of 6 weeks. The outcomes revealed that caffeic acid effectively improved irregular estrous cycles, fasting blood glucose levels, liver function, and lipid profiles in DHEA-induced PCOS rats. Additionally, it mitigated hyperandrogenism, enhanced steroidogenesis enzyme expression, and modulated apoptosis-related protein expression. Our findings strongly suggest that caffeic acid holds promising potential in reducing oxidative stress-induced damage and ameliorating PCOS-related complications by modulating ER stress.

A New Approach to Polycystic Ovary Syndrome and Related Cardio-metabolic Risk Factors: Dietary Polyphenols

PURPOSE OF REVIEW

Polycystic ovarian syndrome (PCOS) is a common endocrine disease characterized by ovulatory dysfunction, hyperandrogenism, and polycystic ovarian morphology and causing various reproductive, metabolic, cardiovascular, oncological, and psychological complications. Recent meta-analyses and systemic reviews showed that PCOS increases the risk factor for various cardio-metabolic complications like insulin resistance, type II diabetes mellitus, dyslipidemia, metabolic syndrome, hypertension, and endothelial dysfunction. In addition to these, it was suggested that chronic low-grade inflammation and oxidative stress are the underlying mechanisms of PCOS-mediated metabolic consequences and might trigger cardio-metabolic risk in women with PCOS. At this point, there is substantial evidence to suggest that various non-nutrient food components modulate cardio-metabolic health together with inflammation and oxidative stress.

RECENT FINDINGS

Increasing the intake of dietary polyphenols might reduce oxidative stress and inflammation and thus alleviate the risk of metabolic, endothelial, and cardiovascular disorders. Nowadays, there are an increasing number of studies related to the effects of dietary polyphenols on PCOS and its accompanying cardio-metabolic disturbances. Currently, there is a cumulative number of studies connected to the effects of dietary polyphenols on PCOS and accompanying cardio-metabolic disturbances. However, there is a lack of knowledge in combining the probable mechanisms of dietary polyphenols on PCOS and related cardio-metabolic consequences. Thus, the effects of dietary polyphenols on PCOS and accompanying cardio-metabolic disturbances need to be discussed and evaluated with underlying mechanisms. Consequently, this review was written to reveal the potential effects of dietary polyphenols on PCOS and related metabolic and cardiovascular risk factors in all their aspects.

Antioxidant, Pro-Survival and Pro-Regenerative Effects of Conditioned Medium from Wharton's Jelly Mesenchymal Stem Cells on Developing Zebrafish Embryos

Conditioned media harvested from stem cell culturing have the potential to be innovative therapeutic tools against various diseases, due to their high content of growth, trophic and protective factors. The evaluation in vivo of the effects and biosafety of these products is essential, and zebrafish provides an ideal platform for high-throughput toxicological analysis, concurrently allowing the minimization of the use of mammalian models without losing reliability. In this study, we assessed the biological effects elicited by the exposure of zebrafish embryos to a conditioned medium derived from Wharton's jelly mesenchymal stem cells. By a multiparametric investigation combining molecular, embryological, behavioural and in vivo imaging techniques, we found that exposure to a conditioned medium at a non-toxic/non-lethal dosage triggers antioxidant, anti-apoptotic and pro-regenerative effects, by upregulation of a set of genes involved in antioxidant defence (nrf2, brg1, sirt1, sirt6, foxO3a, sod2 and cat), glycolysis (ldha) and cell survival (bcl2l1, mcl1a and bim), coupled to downregulation of pro-apoptotic markers (baxa, caspase-3a and caspase-8). To our knowledge, this is the first study comprehensively addressing the effects of a conditioned medium on a whole organism from a developmental, molecular and behavioural perspective, and we are fairly confident that it will pave the way for future therapeutic application.

The Effects of Plant-Derived Phytochemical Compounds and Phytochemical-Rich Diets on Females with Polycystic Ovarian Syndrome: A Scoping Review of Clinical Trials

Polycystic ovarian syndrome (PCOS) is an endocrine condition that impacts nutritional status, metabolic, and hormonal function in females of reproductive age. This condition is associated with increased androgen production (hyperandrogenism) and decreased insulin sensitivity, which often leads to insulin resistance and hyperinsulinemia. This increase in androgen production and insulin resistance is strongly associated with a high incidence of obesity, type-2 diabetes mellitus (T2DM), cardiovascular diseases (CVD), and certain types of gonad-related cancers among females who suffer from this condition. As research continues to grow, it has been demonstrated that PCOS is a complex condition, and some of its characteristics vary among the females that have this disorder. However, it has been suggested that oxidative stress and low-grade chronic inflammation could play an important role in the development of PCOS. Current evidence suggest that phytochemicals could potentially help with weight-loss by reducing oxidative stress and low-grade inflammation, as well as aid in metabolic and hormonal regulation due to their antioxidant properties. Some of the bioactive compounds found in plants that have shown positive effects in the attenuation of PCOS include flavonoids, polyphenols, phytoestrogen, and polyunsaturated fatty acids (PUFAs). Thus, a review of the current literature published on PCOS and phytochemicals was conducted in PubMed, Google Scholar, and the Academy of Nutrition and Dietetics databases for articles published between 2013 and 2023 with a study duration of 1 to 3 months and adequate sample sizes. The main purpose of this review of literature was to investigate the metabolic effects of phytochemical compounds and phytochemical-rich diets on females with PCOS by comparing the results of several randomized clinical trials.

Sirtuins, resveratrol and the intertwining cellular pathways connecting them

Sirtuins are a family of NAD+-dependent deacylases with numerous physiological and pathological implications, which lately became an attractive therapeutic target. Sirtuin-activating compounds (STACs) could be useful in disease prevention and treatment. Despite its bioavailability issues, resveratrol exerts a myriad of beneficial effects, known as the "resveratrol paradox". Modulation of sirtuins' expression and activity may, in fact, underlie many of resveratrol revered actions; however, the cellular pathways affected by modulating the activity of each sirtuin isoform, in different physio-pathological conditions, are not fully known. The purpose of this review was to summarize recent reports concerning the effects of resveratrol on the activity of sirtuins in different experimental settings, focusing on in vitro and in vivo preclinical studies. Most reports concern SIRT1, however recent studies dive into the effects initiated via other isoforms. Numerous cellular signaling pathways were reported to be modulated by resveratrol in a sirtuin-dependent manner (increased phosphorylation of MAPKs, AKT, AMPK, RhoA, BDNF, decreased activation of NLRP3 inflammasome, NF-κB, STAT3, upregulation of SIRT1/SREBP1c pathway, reduced β-amyloid via SIRT1-NF-κB-BACE1 signaling and counteracting mitochondrial damage by deacetylating PGC-1α). Thus, resveratrol may be the ideal candidate in the search for STACs as a tool for preventing and treating inflammatory and neurodegenerative diseases.

Acupuncture regulates the apoptosis of ovarian granulosa cells in polycystic ovarian syndrome-related abnormal follicular development through LncMEG3-mediated inhibition of miR-21-3p

BACKGROUND

The main features of polycystic ovary syndrome (PCOS) are abnormal follicular development and ovulatory dysfunction, which are caused by excessive apoptosis of ovarian granulosa cells. Acupuncture has been shown to improve follicular development abnormalities in patients with PCOS, but its mechanism is unknown. This study hypothesized that the mechanism of acupuncture on follicular development abnormalities in PCOS patients is the inhibition of granulosa cell apoptosis through LncMEG3-mediated regulation of miR-21-3p.

METHODS

A PCOS-like rat model was established using subcutaneous injection of dehydroepiandrosterone (DHEA). Acupuncture was performed on rats for 15 d (CV-4, RN-3, CV-6, SP-6 and EX-CA 1). Ovarian morphology was observed by HE staining, and sex hormone and AMH levels were detected by ELISA. Primary granulosa cells were isolated from each group of rats to assess the association of acupuncture treatment, LncMEG3, miR-21-3p, and granulosa cell apoptosis in rats with PCOS.

RESULTS

LncMEG3 and miR-21-3p were highly expressed in the ovarian granulosa cells of rats with PCOS, and LncMEG3-mediated regulation of miR-21-3p was involved in the development of PCOS in rats. Silencing of MEG3 attenuated sex hormone dysregulation and ovarian histopathological changes in PCOS rats and promoted follicle cell development and maturation. In addition, silencing MEG3 increased the viability and number of granulosa cells. In addition, silencing MEG3 further inhibited early and late apoptosis of ovarian granulosa cells in PCOS rats. Acupuncture improved polycystic ovarian morphology and sex hormone levels in PCOS rats. Acupuncture intervention increased the viability and number of granulosa cells. Acupuncture intervention inhibited early and late apoptosis of ovarian granulosa cells in PCOS rats by targeting miR-21-3p via LncMEG3.

CONCLUSION

These results suggest that acupuncture can downregulate LncMEG3, thereby targeting and regulating miR-21-3p to suppress early and late granulosa cell apoptosis and normalize their proliferation. These factors ultimately compensate for abnormal follicular development. These findings shed light on the clinical potential of acupuncture as a safe treatment for follicular developmental abnormalities in PCOS.

Granulosa cells from immature follicles exhibit restricted glycolysis and reduced energy production: a dominant problem in polycystic ovary syndrome

PURPOSE

We hypothesized that immature oocytes are associated with impaired energy production in surrounding granulosa cells (GCs) in polycystic ovary syndrome (PCOS). Thus, this study investigated mitochondrial function, determined expression of glycolytic regulatory enzymes, and measured ATP levels in GCs of PCOS patients.

METHODS

GCs were isolated from forty-five PCOS patients and 45 control women. Intracellular concentration of reactive oxygen species (ROS), mitochondrial membrane potential (Δψm), the rate of glycolysis, total antioxidant capacity (TAC), activities of catalase (CAT) and superoxide dismutase (SOD), and ATP level were measured in GCs. The gene expression and protein levels of glycolytic enzymes (hexokinase, muscular phosphofructokinase, platelet derived phosphofructokinase, and muscular pyruvate kinase) were determined. Association of GC energy level with oocyte maturation was further validated by measuring glycolysis rate and ATP level in GCs isolated from mature and immature follicles from new set of fifteen PCOS patients and 15 controls.

RESULTS

PCOS patients showed higher ROS level, decreased TAC, reduced CAT and SOD activities, and lower Δψm together with reduced expression of key glycolytic enzymes. ATP concentration and biochemical pregnancy were lower in PCOS compared with control group. ATP levels were found to be significantly correlated with ROS and Δψm (r = - 0.624 and r = 0.487, respectively). GCs isolated from immature follicles had significantly lower ATP levels and rate of glycolysis compared with the GCs separated from mature follicles in both PCOS patients and control.

CONCLUSION

Declined energy due to the mitochondrial dysfunction and restrained glycolysis in GCs is associated with the immature oocytes and lower biochemical pregnancy in PCOS.

Alpha-ketoglutarate ameliorates induced premature ovarian insufficiency in rats by inhibiting apoptosis and upregulating glycolysis

RESEARCH QUESTION

What are the effects of alpha-ketoglutarate (α-KG) treatment on the ovarian morphology and ovarian reserve function of rats with cyclophosphamide (CTX)-induced premature ovarian insufficiency (POI)?

DESIGN

Thirty female Sprague Dawley rats were randomly allocated to a control group (n = 10) and a POI group (n = 20). Cyclophosphamide was administered for 2 weeks to induce POI. The POI group was then divided into two groups: a CTX-POI group (n = 10), administered normal saline, and a CTX-POI + α-KG group (n = 10), administered α-KG 250 mg/kg per day for 21 days. Body mass and fertility was assessed at the end of the study. Serum samples were collected for hormone concentration measurement, and biochemical, histopathological, TUNEL, immunohistochemical and glycolytic pathway analyses were conducted for each group.

RESULTS

The α-KG treatment increased body mass and ovarian index of rats, partially normalized their disrupted estrous cycles, prevented follicular loss, restored ovarian reserve, and increased pregnancy rate and litter sizes of rats with POI. It significantly reduced serum concentration of FSH (P < 0.001), increased that of oestradiol (P<0.001) and reduced apoptosis of granulosa cells (P = 0.0003). Moreover, α-KG increased concentrations of lactate (P = 0.015) and ATP (P = 0.025), reduced that of pyruvate (P<0.001) and increased expression of rate-limiting enzymes of glycolysis in the ovary.

CONCLUSIONS

α-KG treatment ameliorates the deleterious effects of CTX on the fertility of female rats, possibly by reducing the apoptosis of ovarian granulosa cells and restoring glycolysis.

Resveratrol regulates insulin resistance to improve the glycolytic pathway by activating SIRT2 in PCOS granulosa cells

Scope

Insulin resistance (IR) has a close relationship with the main clinical manifestations of patients with PCOS; hence, the research and development of new drugs to treat PCOS by improving IR is a desiderate task at present. Resveratrol (RES) possesses a variety of beneficial pharmacological functions, such as antioxidation, anti-inflammatory, regulating glucose, and lipid metabolism. However, whether RES could improve IR and the underlying mechanisms remained unclear in PCOS.

Methods and results

SD rats received a high-fat diet and letrozole for 30 days to establish the PCOS model and then intervened with RES for 30 days. The results demonstrated that RES played a protective role on the IR in PCOS rats, which significantly decreased the levels of blood glucose and serum insulin, up regulated the expression of IGF1R, and down regulated the expression of IGF1. In vitro, KGN cells were treated with insulin, RES, and AGK2, respectively. We found that a high dose of insulin (4μg/mL) significantly inhibited KGN cell viability, decreased the level of lactic acid, and increased the level of pyruvate, while RES (25μM) attenuated the growth-inhibitory effect, as well as increased the level of lactic acid and decreased the level of pyruvate after high levels of insulin treatment. Simultaneously, RES up regulated the expression level of the crucial rate-limiting enzymes relating to glycolytic pathways, such as LDHA, HK2, and PKM2. Furthermore, AGK2 remarkably inhibited the expression level of SIRT2, which was similar to the same negative effects processed by insulin. Meanwhile, RES overtly repaired the glycolysis process by reversing the levels of lactic acid and pyruvate, together with up regulating the expression level of LDHA, HK2, and PKM2, after AGK2 treatment.

Conclusion

RES could effectively improve insulin resistance and restore the glycolysis pathway by regulating SIRT2, which may contribute to attenuating the ovarian damage of PCOS rats and provide a potential treatment for patients with PCOS.

Role and mechanism of the p-JAK2/p-STAT3 signaling pathway in follicular development in PCOS rats

OBJECTIVE

To identify the association between the phosphorylated Janus kinase 2/phosphorylated signal transducer and activator of transcription (p-JAK2/p-STAT3) signaling pathway and follicular development in polycystic ovary syndrome (PCOS) rats, and explore the underlying mechanism. To evaluate the role of exogenous JAK2 inhibitor AG490 in the model and the associations among luteinizing hormone/choriogonadotropin receptor (LHCGR), follicle-stimulating hormone receptor (FSHR), cytochrome P450 17α (CYP17a), cytochrome P450 19 (CYP19), and PCOS.

RESULTS

Rat models of PCOS was established. PCOS rats were intraperitoneally treated with double-distilled water (ddH2O)/DMSO/AG490. The rate of ovarian morphological recovery in the AG490 group was significantly higher compared with the DMSO group (83.3 % vs 9.1 %, X² = 12.68, P < 0.001). Moreover, the short in the time the estrous cycle was resumed in the AG490 group (hazard ratio = 16.32, P < 0.001) compared with the DMSO group. Compared with the controls, p-JAK2, p-STAT3, LHCGR, and CYP17a expression levels were increased whereas that of FSHR and CYP19 were decreased in the ovaries of PCOS rats. However, an opposite trend was observed after treatment with AG490. Software prediction revealed that the p-STAT3 bound to the promoter regions of LHCGR, FSHR, CYP17a, and CYP19 genes. This finding was confirmed by results of correlation analysis (R = 0.834, -0.836, 0.875 and -0.712, respectively, all P < 0.001).

CONCLUSION

This study demonstrated that the p-JAK2/p-STAT3 signaling pathway was involved in follicular development in PCOS rats by upregulating LHCGR and CYP17a expression, and downregulating that of FSHR and CYP19. AG490 treatment exerted beneficial effects. LHCGR, FSHR, CYP17a, and CYP19 are candidate genes associated with follicular development in PCOS rats.

Resveratrol improves follicular development of PCOS rats via regulating glycolysis pathway and targeting SIRT1

Polycystic ovary syndrome (PCOS) is a disease characterized by metabolic disorders. This study aimed to examine the effects of resveratrol treatment on ovulation in the PCOS rat model. Quantitative real-time PCR and immunohistochemistry were used to determine the mRNA and protein expression levels. TNUEL assay was used to evaluate cell apoptosis in ovary. The metabolites were evaluated by liquid chromatography with tandem mass spectrometry. Resveratrol alleviated disrupted estrous cycle and improved granular cell layers, and reversed the decreased proliferation and increased cell apoptosis of granulosa cells in the ovarian tissues of PCOS rats. Resveratrol restored the changes in the mRNA expression levels in the rate-limiting genes of glycolysis in the PCOS ovary. The expression of lactate dehydrogenase A (LDH-A), pyruvate kinase isozyme M2 (PKM2), and sirtuin 1 (SIRT1) was significantly downregulated in ovarian tissues of the PCOS rats; while the resveratrol treatment significantly increased the expression of LDH-A, PKM2, and SIRT1 in the ovarian tissues of PCOS rats. Collectively, the protective effects of resveratrol in the PCOS rats may be associated with the regulation of glycolysis-related mediators including PKM2, LDH-A, and SIRT1. Resveratrol may represent a good candidate in alleviating the development of PCOS.

Distinctions in PCOS Induced by Letrozole Vs Dehydroepiandrosterone With High-fat Diet in Mouse Model

Polycystic ovarian syndrome (PCOS) is a complex health condition associated with metabolic disturbances and infertility. Recent data suggest that the prevalence of PCOS is increasing among women globally, although the etiology of these trends is undefined. Consequently, preclinical models that better reflect the biology of PCOS are urgently needed to facilitate research that can lead to the discovery of prevention strategies or improved management. The existing animal models have several limitations as they do not reflect all the PCOS features metabolically and/or phenotypically. Therefore, there is no clear consensus on the use of appropriate animal model and selection of the most appropriate PCOS-inducing agent. To that end, we have established a Swiss albino mouse model of PCOS based on 3 weeks of daily treatment with letrozole (50 μg/day; intraperitoneal) and dehydroepiandrosterone (DHEA, 6 mg/100 g body weight; subcutaneous) in 5-week-old female mice fed on normal or high-fat diet (HFD). Mice were regularly assessed for body weight, blood glucose, and estrous cycle. Three weeks after drug administration, mice were sacrificed and assessed for blood-based metabolic parameters as well as ovarian function. Our results indicate that DHEA combined with HFD produces changes mimicking those of clinical PCOS, including elevated serum testosterone and luteinizing hormone, dyslipidemia, poor ovarian microenvironment, and development of multiple ovarian cysts, recapitulating cardinal features of PCOS. In comparison, normal diet and/or letrozole produced fewer features of PCOS. The data from the experimental models presented here can improve our understanding of PCOS, a growing concern in women's health.

PCOS and Role of Cumulus Gene Expression in Assessing Oocytes Quality

The global infertility rate has been declining from year to year. PCOS is one of the treatable accountable causes contributing to anovulatory infertility. Nevertheless, the success rate of treatments and live-birth outcomes especially involving assisted reproductive techniques is still not very promising. There is a reduction in the development potential of oocytes and high-quality embryos in PCOS patients compared to non-PCOS patients. A critical step in IVF treatment is the assessment of oocyte and embryo competence before embryo transfer. Oocytes in metaphase II are very fragile. Repeated morphological assessment on these oocytes may directly impair the quality and affect the whole process. Identification of potential biomarkers especially in the cumulus cells oocytes complex will help to predict the outcome and may create space for improvement. This review has explored gene expression in cumulus cells with regards to oocytes quality in both normal and PCOS women. The gene expression was classified according to their physiological function such as the contribution on cumulus expansion, cumulus cells apoptosis, and glucose metabolism. Collectively, the review suggested that positive expression of HAS2, PTX3, GREM1, and VCAN may correlate with good quality oocytes and can be used as an indicator among PCOS women.

Mogroside V Improves Follicular Development and Ovulation in Young-Adult PCOS Rats Induced by Letrozole and High-Fat Diet Through Promoting Glycolysis

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. In this study, we induced a young-adult PCOS rat model by oral administration of letrozole combined with a high-fat diet and then treated with mogroside V (MV) to evaluate the protective effects of MV on endocrine and follicle development in young-adult PCOS rats. MV (600 mg/kg/day) administration not only significantly reduced the body weight and ovary weight, but also attenuated the disrupted estrous cycle and decreased the level of testosterone. MV restored the follicular development, especially by increasing the number of corpus luteum and the thickness of the granular layer in young-adult POCS rats. Moreover, metabolomics showed that MV markedly increased the levels of D-Glucose 6-phosphate, lactate and GTP, while decreased the level of pyruvate. Bioinformatic analysis revealed that MV recovered multiple metabolism-related processes including gluconeogenesis, glycolysis and glucose metabolic process. Further real-time quantitative PCR analysis showed that MV upregulated the expression of lactate dehydrogenase A (Ldha), hexokinase 2 (Hk2) and pyruvate kinase M2 (Pkm2). Western blotting and immunohistochemistry analysis showed that MV restored the expression of lactate dehydrogenase A (Ldha), hexokinase 2 (Hk2) and pyruvate kinase M2 (Pkm2). Collectively, these findings indicated that MV could effectively improve the ovarian microenvironment by upregulating the expression of LDHA, HK2 and PKM2 in granulosa cells and enhancing lactate and energy production, which may contribute to follicle development and ovulation of young-adult PCOS rats.