Resveratrol and desferoxamine protect human OxLDL-treated granulosa cell subtypes from degeneration

Deferoxamine alleviates chondrocyte senescence and osteoarthritis progression by maintaining iron homeostasis

BACKGROUND

Osteoarthritis (OA) is a prevalent age-related disease characterized by the gradual deterioration of cartilage. The involvement of chondrocyte senescence is crucial in the pathogenesis of OA. Desferoxamine (DFO) is an iron chelator with therapeutic potential in various diseases. However, the relationship of chondrocyte senescence and iron homeostasis is largely unknown.

METHODS

Chondrocyte senescence was induced using tert-butyl hydroperoxide (TBHP), and the impact of DFO on chondrocyte senescence and iron metabolism was assessed through techniques such as western blotting, qRT-PCR, and β-Galactosidase staining. To assess the impact of DFO on chondrocyte senescence and the progression of osteoarthritis (OA), the surgical destabilization of the medial meniscus model was established.

RESULTS

In chondrocytes, TBHP administration resulted in elevated expression of P16, P21, and P53, as well as alterations in SA-β-gal staining. Nevertheless, DFO effectively mitigated chondrocyte senescence induced by TBHP, and reversed the decrease in collagen II expression and increase in MMP13 expression caused by TBHP. Mechanismly, TBHP induced NCOA4 expression and iron release in chondrocytes. Excessive iron could induce chondrocyte senescence, whereas, DFO could inhibit NCOA4 expression and restore ferritin level, and chelate excessive iron. Importantly, intra-articular injection of DFO enhanced collagen II expression and reduced expression of P16, P21, and MMP13 of cartilage in OA mice, and delayed cartilage degeneration.

CONCLUSIONS

Overall, this study provides evidence that DFO has the potential to alleviate chondrocyte senescence induced by TBHP and slow down the progression of osteoarthritis (OA) by effectively chelating excessive iron. These findings suggest that iron chelation could be a promising therapeutic strategy for treating OA.

A Retrospective Review on Dysregulated Autophagy in Polycystic Ovary Syndrome: From Pathogenesis to Therapeutic Strategies

The main purpose of this article is to explore the relationship between autophagy and the pathological mechanism of PCOS, and to find potential therapeutic methods that can alleviate the pathological mechanism of PCOS by targeting autophagy. Relevant literatures were searched in the following databases, including: PubMed, MEDLINE, Web of Science, Scopus. The search terms were "autophagy", "PCOS", "polycystic ovary syndrome", "ovulation", "hyperandrogenemia", "insulin resistance", "inflammatory state", "circadian rhythm" and "treatment", which were combined according to the retrieval methods of different databases. Through analysis, we uncovered that abnormal levels of autophagy were closely related to abnormal ovulation, insulin resistance, hyperandrogenemia, and low-grade inflammation in patients with PCOS. Lifestyle intervention, melatonin, vitamin D, and probiotics, etc. were able to improve the pathological mechanism of PCOS via targeting autophagy. In conclusion, autophagy disorder is a key pathological mechanism in PCOS and is also a potential target for drug development and design.

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.

The Current and Emerging Role of Statins in the Treatment of PCOS: The Evidence to Date

Polycystic ovary syndrome (PCOS) manifests a multifactorial pathology characterized by polycystic ovaries, menstrual cycle disorders, varying degrees of hyperandrogenism, and an ad-verse metabolic risk profile. The position of hyperandrogenism in this syndrome has been extensively studied. A multitude of mechanisms place it in the position of cause but also of consequence; therefore, ongoing research efforts are focused on identifying medications that can effectively reduce levels of androgens in women with PCOS. Moreover, lipid abnormalities are common in this population, with up to 70% of patients having dyslipidemia. Statins may have potential therapeutic benefits for women with PCOS, as they have been shown to improve insulin resistance and reduce the risk of cardiovascular disease. In addition, their role in accelerated steroidogenesis by limiting one source of cholesterol, influencing enzymatic activity, and providing several other beneficial mechanisms is widely investigated. This review aimed to provide a comprehensive overview of the pathogenesis of androgen excess and dyslipidemia in PCOS, as well as the therapeutic potential of statins.

Ampelopsis japonica aqueous extract improves ovulatory dysfunction in PCOS by modulating lipid metabolism

Polycystic ovary syndrome (PCOS) is a highly prevalent endocrine and metabolic disorder that is closely associated with the proliferation and apoptosis of ovarian granulosa cells (GCs). Ampelopsis japonica (AJ) is the dried tuberous root of Ampelopsis japonica (Thunb.) Makino (A. japonica), with anti-inflammatory, antioxidant, antibacterial, antiviral, wound-healing, and antitumor properties; however, it is unclear whether this herb has a therapeutic effect on PCOS. Therefore, this study aimed to investigate the pharmacological effect of AJ on PCOS and reveal its potential mechanism of action. A PCOS rat model was established using letrozole. After establishing the PCOS model, the rats received oral treatment of AJ and Diane-35 (Positive drug: ethinylestradiol + cyproterone tablets) for 2 weeks. Lipidomics was conducted using liquid-phase mass spectrometry and chromatography. AJ significantly regulated serum hormone levels and attenuated pathological variants in the ovaries of rats with PCOS. Furthermore, AJ significantly reduced the apoptotic rate of ovarian GCs. Lipidomic analysis revealed that AJ modulated glycerolipid and glycerophospholipid metabolic pathways mediated by lipoprotein lipase (Lpl), diacylglycerol choline phosphotransferase (Chpt1), and choline/ethanolamine phosphotransferase (Cept1). Therefore, we established that AJ may reduce ovarian GC apoptosis by modulating lipid metabolism, ultimately improving ovulatory dysfunction in PCOS. Therefore, AJ is a novel candidate for PCOS treatment.

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.

Astaxanthin supplementation impact on insulin resistance, lipid profile, blood pressure, and oxidative stress in polycystic ovary syndrome patients: A triple-blind randomized clinical trial

Astaxanthin (ASX) is a natural carotenoid compound found in several of microorganisms and seafood. It may have numerous therapeutic benefits for polycystic ovarian syndrome (PCOS) patients. The aim of this study was to investigate the effect of ASX on lipid profile, insulin resistance (IR), blood pressure (BP), and oxidative stress (OS) levels in infertile PCOS patients. Overall, 58 infertile women with diagnosed PCOS participated in this triple-blind randomized clinical trial. They were randomly assigned to two groups, taking either a placebo or ASX (2 × 6 mg/day) for 8 weeks. Blood serum samples were collected from patients before and after the intervention. Fasting Insulin (FI), fasting blood glucose (FBS), OS markers (malondialdehyde [MDA], superoxide dismutase [SOD], and total antioxidant capacity [TAC]), and lipid profiles were evaluated in serum. Moreover, based on the relevant formula, several indices associated with IR were calculated. BP was also assessed at the start and end of the study. After 8 weeks of ASX consumption, a significant reduction was observed in fasting blood sugar, HOMA-IR, FI, MDA, low-density lipoprotein-cholesterol, and TC/HDL-C. Conversely, ASX significantly increased TAC, HDL-C, and QUICKI. After adjusting the analysis for the baseline values of age, body mass index, and biochemical parameters, non-significant values were obtained for QUICKI and FI, along with no changes in other findings. Overall, ASX appears to be an effective and safe supplement that alleviates insulin metabolism, lipid profile parameters, and OS in infertile PCOS patients.

Effect of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibition on Podocytes in Mouse Nephrotic Syndrome

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is known to play a crucial role in dyslipidemia, and an increase in serum PCSK9 levels has also been reported in patients with nephrotic syndrome (NS). However, the specific effects of PCSK9 in kidney disease and the therapeutic potential of targeting PCSK9 in NS remain elusive. We thus investigated the effects of evolocumab (EVO) in mice with adriamycin (ADR)-induced NS. Male BALB/c mice were divided into the following 4 groups: Control, N = 11; EVO (monoclonal antibody for PCSK9), N = 11; ADR, N = 11; and ADR+EVO, N = 11. We also performed in vitro experiments using immortalized murine podocyte cells to validate the direct effects of PCSK9 on podocytes. EVO decreased urinary albumin levels and ameliorated podocytopathy in mice with ADR nephropathy. Further, EVO suppressed the Nod-like receptor protein 3 (NLRP3) inflammasome pathway in podocytes. PCSK9 expression upregulated CD36, a scavenger receptor of oxidized low-density lipoprotein (Ox-LDL), which in turn stimulated the absorption of Ox-LDL in vitro. EVO downregulated CD36 expression in podocytes both in vitro and in vivo. Immunofluorescence staining analysis reveals that CD36 and PCSK9 colocalized in the glomerular tufts of mice with ADR nephropathy. In the patients with focal segmental glomerulosclerosis, the CD36+ area in glomerular tufts increased compared with those diagnosed with minor glomerular abnormalities. This study revealed that EVO ameliorated mouse ADR nephropathy through the regulation of CD36 and NLRP3 inflammasome signaling. EVO treatment represents a potential therapeutic strategy for human NS.

Mitochondrial dysfunction in the offspring of obese mothers and it's transmission through damaged oocyte mitochondria: Integration of mechanisms

In vivo and in vitro studies demonstrate that mitochondria in the oocyte, are susceptible to damage by suboptimal pre/pregnancy conditions, such as obesity. These suboptimal conditions have been shown to induce mitochondrial dysfunction (MD) in multiple tissues of the offspring, suggesting that mitochondria of oocytes that pass from mother to offspring, can carry information that can programme mitochondrial and metabolic dysfunction of the next generation. They also suggest that transmission of MD could increase the risk of obesity and other metabolic diseases in the population inter- and trans-generationally. In this review, we examined whether MD observed in offspring tissues of high energetic demand, is the result of the transmission of damaged mitochondria from obese mothers' oocytes to the offspring. The contribution of genome-independent mechanisms (namely mitophagy) in this transmission were also explored. Finally, potential interventions aimed at improving oocyte/embryo health were investigated, to see if they may provide an opportunity to halter the generational effects of MD.

Influence of Subclinical Hypothyroidism on Women With Polycystic Ovary Syndrome: A Literature Review

Subclinical hypothyroidism (SCH) is a commonly encountered condition in women with polycystic ovary syndrome (PCOS). Nevertheless, it is unclear whether SCH has any potential impact on the metabolic and reproductive profiles of women with PCOS. Hence, this literature review explores and establishes the link between these two conditions. In women with PCOS, SCH was found to aggravate insulin resistance and dyslipidemia. It was also linked to hormonal imbalances leading to higher infertility rates among the PCOS-SCH group. Therefore, women with PCOS must be screened for thyroid function frequently and managed accordingly.

Effects of Androgen Excess-Related Metabolic Disturbances on Granulosa Cell Function and Follicular Development

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disease in women of reproductive age. Ovarian dysfunction including abnormal steroid hormone synthesis and follicular arrest play a vital role in PCOS pathogenesis. Hyperandrogenemia is one of the important characteristics of PCOS. However, the mechanism of regulation and interaction between hyperandrogenism and ovulation abnormalities are not clear. To investigate androgen-related metabolic state in granulosa cells of PCOS patients, we identified the transcriptome characteristics of PCOS granulosa cells by RNA-seq. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differentially expressed genes (DEGs) revealed that genes enriched in lipid metabolism pathway, fatty acid biosynthetic process and ovarian steroidogenesis pathway were abnormally expressed in PCOS granulosa cells in comparison with that in control. There are close interactions among these three pathways as identified by analysis of the protein-protein interaction (PPI) network of DEGs. Furthermore, in vitro mouse follicle culture system was established to explore the effect of high androgen and its related metabolic dysfunction on follicular growth and ovulation. RT-qPCR results showed that follicles cultured with dehydroepiandrosterone (DHEA) exhibited decreased expression levels of cumulus expansion-related genes (Has2, Ptx3, Tnfaip6 and Adamts1) and oocyte maturation-related genes (Gdf9 and Bmp15), which may be caused by impaired steroid hormone synthesis and lipid metabolism, thus inhibited follicular development and ovulation. Furthermore, the inhibition effect of DHEA on follicle development and ovulation was ameliorated by flutamide, an androgen receptor (AR) antagonist, suggesting the involvement of AR signaling. In summary, our study offers new insights into understanding the role of androgen excess induced granulosa cell metabolic disorder in ovarian dysfunction of PCOS patients.

In Vitro Folliculogenesis in Mammalian Models: A Computational Biology Study

In vitro folliculogenesis (ivF) has been proposed as an emerging technology to support follicle growth and oocyte development. It holds a great deal of attraction from preserving human fertility to improving animal reproductive biotechnology. Despite the mice model, where live offspring have been achieved,in medium-sized mammals, ivF has not been validated yet. Thus, the employment of a network theory approach has been proposed for interpreting the large amount of ivF information collected to date in different mammalian models in order to identify the controllers of the in vitro system. The WoS-derived data generated a scale-free network, easily navigable including 641 nodes and 2089 links. A limited number of controllers (7.2%) are responsible for network robustness by preserving it against random damage. The network nodes were stratified in a coherent biological manner on three layers: the input was composed of systemic hormones and somatic-oocyte paracrine factors; the intermediate one recognized mainly key signaling molecules such as PI3K, KL, JAK-STAT, SMAD4, and cAMP; and the output layer molecules were related to functional ivF endpoints such as the FSH receptor and steroidogenesis. Notably, the phenotypes of knock-out mice previously developed for hub.BN indirectly corroborate their biological relevance in early folliculogenesis. Finally, taking advantage of the STRING analysis approach, further controllers belonging to the metabolic axis backbone were identified, such as mTOR/FOXO, FOXO3/SIRT1, and VEGF, which have been poorly considered in ivF to date. Overall, this in silico study identifies new metabolic sensor molecules controlling ivF serving as a basis for designing innovative diagnostic and treatment methods to preserve female fertility.

Biological and clinical effects of a resveratrol-based multivitamin supplement on intracytoplasmic sperm injection cycles: a single-center, randomized controlled trial

BACKGROUND

Resveratrol display's positive effects on follicle growth and development in preclinical studies while there is scantly information from clinical trials. The aim of this study was to evaluate the biological and clinical impact of a resveratrol-based multivitamin supplement on intracytoplasmatic sperm injection (ICSI) cycles.

METHODS

A randomized, single-center controlled trial conducted at the University Center of Assisted Reproductive Technologies involving 101 women infertile women undergoing ICSI cycles was conducted. A pretreatment with a daily resveratrol based nutraceutical was administered to the Study Group; Control Group received folic acid. The primary outcomes were the number of developed mature follicles (>16 mm), total oocytes and MII oocytes recovered, the fertilization rate and the number of cleavage embryos/blastocysts obtained. Secondary endpoints were the duration and dosage of gonadotropins, the number of embryos for transfer, implantation, biochemical, clinical pregnancy rates, live birth and miscarriage rates.

RESULTS

A significantly higher number of oocytes and MII oocytes were retrieved in the Study Group than in Control Group (p = .03 and p = .04, respectively). A higher fertilization rate (p = .004), more cleavage embryos/patient (p = .01), blastocytes/patients (p = .01) and cryopreserved embryos (p = .03) were obtained in the Study Group. No significant differences in biochemical or clinical pregnancy, live birth, and miscarriage rates were revealed, but a trend to a higher live birth rate was revealed in the Study Group.

CONCLUSIONS

A 3 months period of dietary supplementation with a resveratrol-based multivitamin nutraceutical leads to better biological effects on ICSI cycles.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov registration identifier: NCT04386499.

Resveratrol depolarizes the membrane potential in human granulosa cells and promotes mitochondrial biogenesis

OBJECTIVE

To study the biological effects of resveratrol on the growth, electrophysiology, and mitochondrial function of human granulosa cells (h-GCs).

DESIGN

Preclinical study.

SETTING

Electrophysiology laboratory and in vitro fertilization unit.

PATIENT(S)

This study included h-GCs from seven infertile women undergoing assisted reproductive techniques.

INTERVENTION(S)

Human ovarian Granulosa Cell Tumor (GCT) cell line COV434 and h-GCs obtained after oocyte retrieval were cultured in the absence or presence of resveratrol.

MAIN OUTCOME MEASURE(S)

Granulosa cells were evaluated for cell viability and mitochondrial activity. Electrophysiological recordings and evaluation of potassium current (IKur) and Ca₂₊ concentration were also performed.

RESULT(S)

Resveratrol induced mitochondrial activity in a bell-shaped, dose-effect-dependent manner. Specifically, resveratrol treatment (3 μM, 48 hours) increased ATP production and cell viability and promoted the induction of cellular differentiation. These biological changes were associated with mitochondrial biogenesis. Electrophysiological recordings showed that resveratrol reduced the functional expression of an ultra rapid activating, slow inactivating, delayed rectifier potassium current (IKur) that is associated with a plasma membrane depolarization and that promotes an increase in intracellular Ca₂⁺_. CONCLUSION(S): The effects of resveratrol on potassium current and mitochondrial biogenesis in h-GCs could explain the beneficial effects of this polyphenol on the physiology of the female reproductive system. These findings suggest there are therapeutic implications of resveratrol in a clinical setting.

High BMI and Insulin Resistance Are Risk Factors for Spontaneous Abortion in Patients With Polycystic Ovary Syndrome Undergoing Assisted Reproductive Treatment: A Systematic Review and Meta-Analysis

Background

The risk of spontaneous abortion in patients with polycystic ovary syndrome (PCOS) undergoing assisted reproductive treatment (ART) is higher than that in patients without PCOS, however, no definitive risk factors have been confirmed to associate with the high spontaneous abortion rate in PCOS patients undergoing ART. This study was performed to assess the impact of relevant risk factors on spontaneous abortion in patients with PCOS. Clinical questions were formulated and organized according to the PICOS principle.

Methods

A systematic review and meta-analysis were conducted on all published studies on PCOS and spontaneous abortion in Embase, PubMed, Web of Science and Cochrane Library. Related risk factors included body mass index (BMI), age, insulin resistance (IR), hyperandrogenism, and chromosome aberrations. All patients were diagnosed as PCOS using the Rotterdam criteria. The primary endpoint was miscarriage and live birth rate. Fixed-effect models were used to analyze homogeneous data, and subgroup and sensitivity analyses were performed on heterogeneous data. The source of heterogeneity was evaluated, and the random effect model was used to summarize the heterogeneity.

Results

Among 1836 retrieved articles, 22 were eligible and included in the analysis with 11182 patients. High BMI (OR = 1.48, 95% CI [1.32, 1.67], MD = 1.35, 95% CI [0.58,2.12]) and insulin resistance (MD = 0.32, 95% CI [0.15, 0.49]) were associated with an increased risk of spontaneous abortion in PCOS patients undergoing ART. Older age (OR = 0.29, 95% CI [0.29, 0.44], MD = 2.01, 95% CI [0.04, 4.18]), embryonic chromosomal aberrations (OR = 0.75, 95%CI [0.31,1.77]), and hyperandrogenism (MD = 0.10, 95% CI [- 0.02, 0.22]) were not associated with the high spontaneous abortion rate in patients with PCOS. A subgroup analysis of BMI showed that there was no statistically significant difference in the effect between overweight and obesity on spontaneous abortion in PCOS patients undergoing ART (OR = 1.34, 95% [0.97, 1.85]).

Conclusion

High BMI and insulin resistance are two risk factors for an increased risk of spontaneous abortion in PCOS patients undergoing ART, and losing weight and mitigating insulin resistance may decrease the spontaneous abortion rate in these patients undergoing ART.

Ameliorating Effects of Natural Antioxidant Compounds on Female Infertility: a Review

The prevalence of female infertility cases has been increasing at a frightening rate, affecting approximately 48 million women across the world. However, oxidative stress has been recognized as one of the main mediators of female infertility by causing various reproductive pathologies in females such as endometriosis, PCOS, preeclampsia, spontaneous abortion, and unexplained infertility. Nowadays, concerned women prefer dietary supplements with antioxidant properties over synthetic drugs as a natural way to lessen the oxidative stress and enhance their fertility. Therefore, the current review is an attempt to explore the efficacy of various natural antioxidant compounds including vitamins, carotenoids, and plant polyphenols and also of some medicinal plants in improving the fertility status of females. Our summarization of recent findings in the current article would pave the way toward the development of new possible antioxidant therapy to treat infertility in females. Natural antioxidant compounds found in fruits, vegetables, and other dietary sources, alone or in combination with other antioxidants, were found to be effective in ameliorating the oxidative stress-mediated infertility problems in both natural and assisted reproductive settings. Numerous medicinal plants showed promising results in averting the various reproductive disorders associated with female infertility, suggesting a plant-based herbal medicine to treat infertility. Although optimum levels of natural antioxidants have shown favorable results, however, their excessive intake may have adverse health impacts. Therefore, larger well-designed, dose-response studies in humans are further warranted to incorporate natural antioxidant compounds into the clinical management of female infertility.

The Stemness of Human Ovarian Granulosa Cells and the Role of Resveratrol in the Differentiation of MSCs-A Review Based on Cellular and Molecular Knowledge

Ovarian Granulosa Cells (GCs) are known to proliferate in the developing follicle and undergo several biochemical processes during folliculogenesis. They represent a multipotent cell population that has been differentiated to neuronal cells, chondrocytes, and osteoblasts in vitro. However, progression and maturation of GCs are accompanied by a reduction in their stemness. In the developing follicle, GCs communicate with the oocyte bidirectionally via gap junctions. Together with neighboring theca cells, they play a crucial role in steroidogenesis, particularly the production of estradiol, as well as progesterone following luteinization. Many signaling pathways are known to be important throughout the follicle development, leading either towards luteinization and release of the oocyte, or follicular atresia and apoptosis. These signaling pathways include cAMP, PI3K, SMAD, Hedgehog (HH), Hippo and Notch, which act together in a complex manner to control the maturation of GCs through regulation of key genes, from the primordial follicle to the luteal phase. Small molecules such as resveratrol, a phytoalexin found in grapes, peanuts and other dietary constituents, may be able to activate/inhibit these signaling pathways and thereby control physiological properties of GCs. This article reviews the current knowledge about granulosa stem cells, the signaling pathways driving their development and maturation, as well as biological activities of resveratrol and its properties as a pro-differentiation agent.

Dyslipidemia involvement in the development of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is widely accepted as the most common endocrine abnormality in women of childbearing age and may be accompanied by dyslipidemia, hyperandrogenism, hyperinsulinemia, oxidative stress and infertility. Dyslipidemia is now known to play an important role in the development of PCOS. Lipid abnormalities, including elevated low-density lipoprotein and triglyceride levels and reduced high-density lipoprotein levels, are often found in women with PCOS and play an important role in PCOS; therefore, we summarize the effect of lipid abnormalities on hyperandrogenism, insulin resistance, oxidative stress and infertility in PCOS and review the effects of common lipid-lowering drugs on patients with PCOS. The purpose of this article is to elucidate the mechanisms of lipid metabolism abnormalities in the development of PCOS.

CD36- and obesity-associated granulosa cells dysfunction

Emerging evidence indicates that obesity impairs granulosa cell (GC) function, but the underlying mechanisms remain unclear. Gene expression profiles in GC of non-polycystic ovary syndrome (PCOS) obese (NPO), PCOS obese (PO), PCOS normal weight (PN) and non-PCOS normal weight (NPN) patients were analysed by microarray analysis. Compared with the NPN group, there were 16, 545 and 416 differently expressed genes in the NPO, PO and PN groups respectively. CD36 was the only intersecting gene, with greater than two fold changes in expression between the NPO versus NPN and PO versus NPN comparisons, and was not present in the PN versus NPN comparison. In addition, levels of CD36 protein were higher in GC from obese than normal weight patients. Furthermore, CD36 overexpression in a GC line inhibited cell proliferation, as determined by the cell counting kit-8 (CCK8) test, promoted cell apoptosis, as determined by flow cytometry, and inhibited the secretion of oestradiol by depositing triglyceride in cells and increasing cellular lipid peroxide levels. These adverse effects were reduced by sulfo-N-succinimidyloleate, a specific inhibitor of CD36. Together, the findings of this study suggest that obesity with and without PCOS should be regarded as separate entities, and that CD36 overexpression in GC of obese patients is one of the mechanisms by which obesity impairs GC function.

Pharmacological modulation of autophagy as a novel potential target in the successful implementation of in vitro fertilization

Autophagy is an important intracellular process to maintain homeostasis and studies have shown the key role of autophagy in modulating the functions of reproductive system. Alongside with it, the activation of autophagy has also been found to regulate a number of important processes involved in in vitro fertilization including degeneration of granulosa cells and oocyte defects in obese and aging women; apoptosis of oocytes during vitrification-warming; quality and viability of embryo; developmental competence and pre-implantation development of in vitro produced blastocysts; placental vascularization and fetal growth. The different mechanisms that may contribute in autophagy-mediated increase in developmental competence and pre-implantation development include decrease in endoplasmic reticulum (ER) stress, activation of poly(ADP-ribosyl)ation (PARP) and reduction in free radical production. The present review discusses the role of autophagy activation in increasing the efficiency of in vitro fertilization by modulating different aspects related to fertilization.

Identification of microRNAs as potential markers of ovarian toxicity

Exposure to environmental toxicants has been associated with ovarian dysfunction yet sensitive biomarkers of adverse effect are lacking. We previously demonstrated that cigarette smoke exposure induced decreased relative ovarian weight, increased follicle loss and granulosa cell autophagy in mice. We postulate that cigarette smoke exposure will induce changes in the epigenome that can be used to reveal potential sensitive biomarkers of ovarian toxicity. Therefore, we evaluated differences in expression of 940 microRNAs (miRNAs), environmentally responsive small non-coding genes that regulate expression of genes at the post-transcriptional level, in ovarian tissue from 8-week-old female C57BL/6 mice exposed to room air or cigarette smoke 5 days per week for 8 weeks. A total of 152 miRNAs were dysregulated in expression, 17 of which were examined with quantitative polymerase chain reaction analysis. Using an online miRNA database tool, complete lists of predicted miRNA gene targets were generated, 12 of which were measured for their expression levels with quantitative polymerase chain reaction. An online bioinformatics resource database, DAVID generated functional classification lists of the target genes and their associated biological pathways. Results of the present pilot study suggest that miR-379, miR-15b, miR-691, miR-872 and miR-1897-5p are potentially useful markers of ovarian toxicity and dysfunction. Examination of the expression pattern of the target mRNA for these miRNA species demonstrated that cigarette smoke exposure induced significant changes that affect mitogen-activated protein kinase signaling pathways. We therefore suggest that miRNAs could serve as sensitive markers of ovarian toxicity and elucidate affected pathways.

Oxidized low-density lipoprotein suppresses mouse granulosa cell differentiation through disruption of the hypoxia-inducible factor 1 pathway

Obesity predisposes women to reproductive disorders. One symptom of obesity in women is higher levels of oxidized Low-density lipoprotein (oxLDL) in serum and preovulatory follicles. The present study was designed to test the hypothesis that oxLDL might impair follicle differentiation and luteinization. Given that Hypoxia-inducible factor 1 (HIF1) plays crucial roles in supporting follicle differentiation and luteinization in mammals, we focused on oxLDL-mediated events that may affect the HIF1 pathway. We report that exposure to oxLDL diminished the expression of HIF1α and its target genes and suppressed the differentiation of mouse luteinized granulosa cells following induction by human Chorionic gonadotophin (hCG) under hypoxic conditions (1% oxygen). Significantly, the proteasome inhibitor MG-132 prevented this oxLDL-attenuation differentiation phenotype by blocking HIF1α degradation. Together, these findings suggest that suppression of granulosa cell differentiation by oxLDL, via HIF1α down-regulation, may contribute the negative effects of obesity on female fertility.

MicroRNA let-7g regulates mouse granulosa cell autophagy by targeting insulin-like growth factor 1 receptor

As an important type of somatic cell, granulosa cells play a major role in deciding the fate of follicles. Therefore, analyses of granulosa cell apoptosis and follicular atresia have become hotspots of animal research. Autophagy is a cellular catabolic mechanism that protects cells from stress conditions, including starvation, hypoxia, and accumulation of misfolded proteins. However, the relationship between autophagy and apoptosis in granulosa cells is not well known. Here, we demonstrate that let-7g regulates the mouse granulosa cell autophagy signaling pathway by inhibiting insulin-like growth factor 1 receptor expression and affecting the phosphorylation of protein kinase B/mammalian target of rapamycin. Small interference-mediated knockdown of insulin-like growth factor 1 receptor significantly promoted autophagy signaling of mouse granulosa cells. In contrast, overexpression of insulin-like growth factor 1 receptor in mouse granulosa cells attenuated autophagy activity in the presence of let-7g. In addition, overexpression of let-7g increased the apoptosis rate, as indicated by an increased number of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-positive cells. Finally, 3-methyladenine as well as the lysosomal enzyme inhibitor chloroquine partially blocked apoptosis. In summary, this study demonstrates that let-7g regulates autophagy in mouse granulosa cells by targeting insulin-like growth factor 1 receptor and downregulating protein kinase B/mammalian target of rapamycin signaling, and that mouse granulosa cell autophagy induced by let-7g participates in apoptosis.

Inactivation of the LOX-1 pathway promotes the Golgi apparatus during cell differentiation of mural granulosa cells

In female mammals, granulosa cells of the ovarian follicle differentiate into the corpus luteum after ovulation of the pregnable oocyte into the fallopian tube. During these differentiation processes several morphological alterations have to occur and the molecular basis is not fully understood. As an endpoint estradiol production from granulosa cells has to switch off in favor for progesterone production from the proceeding corpus luteum to sustain the developing embryo. Previously, we demonstrated that the multiligand receptor LOX-1 plays a critical role in steroid hormone synthesis of granulosa cells via intracellular calcium release from endoplasmic (ER)-dependent and ER-independent calcium pools. In the present study, we show that inhibition of LOX-1 leads to a rearrangement of ceramide from the basal membrane toward the Golgi apparatus. This activity is accomplished by a calcium-dependent phosphorylation of aromatase, the key step in estradiol production. Phosphorylated aromatase increased estradiol production in a dose-dependent manner. Our data indicate that the ceramide cascade is essential for proper granulosa cell function and ceramide redistribution serves as a first step in order to proceed with the prosperous differentiation into a corpus luteum.