Dehydroepiandrosterone-induced activation of mTORC1 and inhibition of autophagy contribute to skeletal muscle insulin resistance in a mouse model of polycystic ovary syndrome

Role of the mitophagy-apoptosis axis in the pathogenesis of polycystic ovarian syndrome

AIM

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by menstrual irregularities, androgen excess, and polycystic ovarian morphology, but its pathogenesis remains largely unknown. This review focuses on how androgen excess influences the molecular basis of energy metabolism, mitochondrial function, and mitophagy in granulosa cells and oocytes, summarizes our current understanding of the pathogenesis of PCOS, and discuss perspectives on future research directions.

METHODS

A search of PubMed and Google Scholar databases were used to identify relevant studies for this narrative literature review.

RESULTS

Female offspring born of pregnant animals exposed to androgens recapitulates the PCOS phenotype. Abnormal mitochondrial morphology, altered expression of genes related to glycolysis, mitochondrial biogenesis, fission/fusion dynamics, and mitophagy have been identified in PCOS patients and androgenic animal models. Androgen excess causes uncoupling of the electron transport chain and depletion of the cellular adenosine 5'-triphosphate pool, indicating further impairment of mitochondrial function. A shift toward mitochondrial fission restores mitochondrial quality control mechanisms. However, prolonged mitochondrial fission disrupts autophagy/mitophagy induction due to loss of compensatory reserve for mitochondrial biogenesis. Disruption of compensatory mechanisms that mediate the quality control switch from mitophagy to apoptosis may cause a disease phenotype. Furthermore, genetic predisposition, altered expression of genes related to glycolysis and oxidative phosphorylation, or a combination of these factors may also contribute to the development of PCOS.

CONCLUSION

In conclusion, fetuses exposed to a hyperandrogenemic intrauterine environment may cause the PCOS phenotype possibly through disruption of the compensatory regulation of the mitophagy-apoptosis axis.

The Novel Insight of Gut Microbiota from Mouse Model to Clinical Patients and the Role of NF-κB Pathway in Polycystic Ovary Syndrome

Polycystic Ovary Syndrome (PCOS) is a metabolic disorder characterized by hyperandrogenism and related symptoms in women of reproductive age. Emerging evidence suggests that chronic low-grade inflammation plays a significant role in the development of PCOS. The gut microbiota, a complex bacterial ecosystem, has been extensively studied for various diseases, including PCOS, while the underlying mechanisms are not fully understood. This review comprehensively summarizes the changes in gut microbiota and metabolites observed in PCOS and their potential association with the condition. Additionally, we discuss the role of abnormal nuclear factor κB signaling in the pathogenesis of PCOS. These findings offer valuable insights into the mechanisms of PCOS and may pave the way for the development of control and therapeutic strategies for this condition in clinical practice. By bridging the gap between mouse models and clinical patients, this review contributes to a better understanding of the interplay between gut microbiota and inflammation in PCOS, thus paving new ways for future investigations and interventions.

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.

Association of metabolic-dysfunction associated steatotic liver disease with polycystic ovary syndrome

Non-alcoholic fatty liver disease (NAFLD), which has a prevalence of over 25% in adults, encompasses a wide spectrum of liver diseases. Metabolic-dysfunction associated steatotic liver disease (MASLD), the new term for NAFLD, is characterized by steatotic liver disease accompanied by cardiometabolic criteria, showing a strong correlation with metabolic diseases. Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disease affecting 4-21% of women of reproductive age. Numerous studies have indicated that NAFLD and PCOS often occur together. However, as MASLD is a new term, there is still a lack of reports describing the effects of MASLD on the development of PCOS. In this review article, we have summarized the complex and multifaceted connections between MASLD and PCOS. Understanding the pathogenesis and treatment methods could not only guide the clinical prevention, diagnosis, and treatment of PCOS in patients with MASLD, but also increase the clinical attention of reproductive doctors to MASLD.

Chinese herbal medicine alleviates autophagy and apoptosis in ovarian granulosa cells induced by testosterone through PI3K/AKT1/FOXO1 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine and metabolic disorder. Chinese herbal medicine has some advantages in the treatment of PCOS with its unique theoretical system and rich clinical practice experiences.

AIM OF THE STUDY

The present study was to investigate the potential mechanisms of Bu-Shen-Jian-Pi Formula (BSJPF) on the treatment of PCOS.

MATERIAL AND METHODS

The combination of ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS/MS) rapid analysis, network pharmacology, molecular docking analysis and bio-experiments were firstly conducted to identify the main effective components of BSJPF, and to predict the potential mechanisms. The ovarian granulosa cell line (KGN) was treated with testosterone to construct the PCOS model in vitro, and the cells were further treated with the lyophilized powder of BSJPF. The levels of proliferation, autophagy and apoptosis were detected to explore the mechanisms of BSJPF on treating PCOS.

RESULTS

Firstly, thirty-six active compounds were identified in BSJPF and thirty-one potential targets on PCOS were found. Then, PI3K and PDK1 were verified to have good binding activity with the active compounds through molecular docking analysis. In bio-experiments, BSJPF significantly alleviated the arrested proliferation of KGN cells in G0/G1 phase and reduced the active levels of autophagy and apoptosis of KGN cells induced by testosterone. Additionally, the inhibition of autophagy diminished apoptosis, while the repression apoptosis enhanced autophagy. Finally, BSJPF significantly decreased the FOXO1 expression levels induced by testosterone, especially for nuclear FOXO1, and significantly activated the PI3K/AKT pathway.

CONCLUSIONS

BSJPF significantly alleviated the activated autophagy and apoptosis in KGN induced by testosterone through PI3K/AKT1/FOXO1pathway, which is an effective treatment for PCOS.

Molecular Mechanisms in the Etiology of Polycystic Ovary Syndrome (PCOS): A Multifaceted Hypothesis Towards the Disease with Potential Therapeutics

Among the premenopausal women, Polycystic Ovary Syndrome (PCOS) is the most prevalent endocrinopathy affecting the reproductive system and metabolic rhythms leading to disrupted menstrual cycle. Being heterogeneous in nature it is characterized by complex symptomology of oligomennorhoea, excess of androgens triggering masculine phenotypic appearance and/or multiple follicular ovaries. The etiology of this complex disorder remains somewhat doubtful and the researchers hypothesize multisystem links in the pathogenesis of this disease. In this review, we attempt to present several hypotheses that tend to contribute to the etiology of PCOS. Metabolic inflexibility, aberrant pattern of gonadotropin signaling along with the evolutionary, genetic and environmental factors have been discussed. Considered a lifelong endocrinological implication, no universal treatment is available for PCOS so far however; multiple drug therapy is often advised along with simple life style intervention is mainly advised to manage its cardinal symptoms. Here we aimed to present a summarized view of pathophysiological links of PCOS with potential therapeutic strategies.

The constructive and destructive impact of autophagy on both genders' reproducibility, a comprehensive review

Reproduction is characterized by a series of massive renovations at molecular, cellular, and tissue levels. Recent studies have strongly tended to reveal the involvement of basic molecular pathways such as autophagy, a highly conserved eukaryotic cellular recycling, during reproductive processes. This review comprehensively describes the current knowledge, updated to September 2022, of autophagy contribution during reproductive processes in males including spermatogenesis, sperm motility and viability, and male sex hormones and females including germ cells and oocytes viability, ovulation, implantation, fertilization, and female sex hormones. Furthermore, the consequences of disruption in autophagic flux on the reproductive disorders including oligospermia, azoospermia, asthenozoospermia, teratozoospermia, globozoospermia, premature ovarian insufficiency, polycystic ovarian syndrome, endometriosis, and other disorders related to infertility are discussed as well.Abbreviations: AKT/protein kinase B: AKT serine/threonine kinase; AMPK: AMP-activated protein kinase; ATG: autophagy related; E2: estrogen; EDs: endocrine disruptors; ER: endoplasmic reticulum; FSH: follicle stimulating hormone; FOX: forkhead box; GCs: granulosa cells; HIF: hypoxia inducible factor; IVF: in vitro fertilization; IVM: in vitro maturation; LCs: Leydig cells; LDs: lipid droplets; LH: luteinizing hormone; LRWD1: leucine rich repeats and WD repeat domain containing 1; MAP1LC3: microtubule associated protein 1 light chain 3; MAPK: mitogen-activated protein kinase; MTOR: mechanistic target of rapamycin kinase; NFKB/NF-kB: nuclear factor kappa B; P4: progesterone; PCOS: polycystic ovarian syndrome; PDLIM1: PDZ and LIM domain 1; PI3K: phosphoinositide 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns3K: class III phosphatidylinositol 3-kinase; POI: premature ovarian insufficiency; ROS: reactive oxygen species; SCs: Sertoli cells; SQSTM1/p62: sequestosome 1; TSGA10: testis specific 10; TST: testosterone; VCP: vasolin containing protein.

Crosstalk between autophagy and insulin resistance: evidence from different tissues

Insulin is a critical hormone that promotes energy storage in various tissues, as well as anabolic functions. Insulin resistance significantly reduces these responses, resulting in pathological conditions, such as obesity and type 2 diabetes mellitus (T2DM). The management of insulin resistance requires better knowledge of its pathophysiological mechanisms to prevent secondary complications, such as cardiovascular diseases (CVDs). Recent evidence regarding the etiological mechanisms behind insulin resistance emphasizes the role of energy imbalance and neurohormonal dysregulation, both of which are closely regulated by autophagy. Autophagy is a conserved process that maintains homeostasis in cells. Accordingly, autophagy abnormalities have been linked to a variety of metabolic disorders, including insulin resistance, T2DM, obesity, and CVDs. Thus, there may be a link between autophagy and insulin resistance. Therefore, the interaction between autophagy and insulin function will be examined in this review, particularly in insulin-responsive tissues, such as adipose tissue, liver, and skeletal muscle.

Molecular cloning and characterization of Sirt1 and its role in the follicle of juvenile Chinese soft-shelled turtle (Pelodiscus sinensis)

Sirt1 is a member of the Sirtuins family that regulates ovarian senescence, follicular development, and oocyte maturation in vertebrates. To understand its role in the ovary of Pelodiscus sinensis, we cloned the full-length cDNA of Ps-Sirt1 and characterized its potential function by intraperitoneally injecting agonist (resveratrol) and antagonist (EX527) in the female juvenile turtle. The full-length cDNA of Ps-Sirt1 was 2106 bp, comprising 203 bp 5'UTR, a 226 bp 3'UTR, and a 1677 bp ORF encoding 558 amino acids. The calculated molecular weight of predicted protein was 63 kDa, and the isoelectric point was 4.65. The predicted protein comprised a conserved Sir2 domain. Amino acid sequence alignment and phylogenetic analyses showed that Ps-Sirt1 was most closely related to turtles, and distantly related to fish. Expression pattern analysis showed Ps-Sirt1 was highest expressed in ovary, followed by testis, liver, heart, and brain. In the ovarian differentiation processes, Sirt1 showed significantly higher expression at embryonic stage 15 and 21. In the testis differentiation process, Sirt1 expression was downregulated at embryonic stages 15-19. Activated and inactivated Sirt1 decreased the number of primordial follicles in juvenile turtles. Bcl2, Bax, mTOR, and rpS6 expressions were up-regulated, whereas GnRH, Fshb, p50, and p65 were down-regulated after agonist treatment. The inaction of Sirt1 with antagonist up-regulated GnRH, Fshb, p65, p53, Foxo3a, Bcl2, Bax, mTOR, and rpS6, but down-regulated p50. In summary, Sirt1 might be involved in the ovarian follicle development of P. sinensis.

Effects of myo-inositol plus folic acid on ovarian morphology and oocyte quality in PCOS mouse model

Although the role of myo-inositol (MYO) in promoting the oocyte quality of PCOS patients has been documented in human studies; the cellular effects of this supplement on oocytes have not been directly examined due to ethical limitations. In the first phase of this study, MYO dosimetry was carried out simultaneously with the PCOS model development. An effective dose was obtained following the assessment of fasting insulin and testosterone levels using ELISA and ovarian morphology appraisal by histopathology. In the second phase, following the continuous administration of the effective dose of MYO and dehydroepiandrosterone (DHEA), cellular evaluation was performed. The quality of oocytes from superovulation was analyzed by examining maturity and normal morphology percentage using a stereomicroscope, intracellular reactive oxygen species (ROS) and glutathione (GSH) levels using fluorometry, and ATP count evaluation using ELISA. The results revealed that, among the four different MYO concentrations, the 0.36 mg/g dose compared with the DHEA group reduced testosterone levels and large atretic antral follicles (LAtAnF) diameter. This dose also increased the corpus luteum count and the granulosa:theca (G/T)layer thickness ratio in antral follicles. Furthermore, this dose increased mature oocytes and normal morphology percentage, ATP count, and GSH levels; however, it decreased ROS levels in mature oocytes. Our findings provide the grounds for further cellular and molecular studies on the PCOS mouse model, suggesting that the improvement in mitochondrial function and its antioxidant properties is probably one of the mechanisms by which MYO increases oocyte quality.

Insulin resistance, autophagy and apoptosis in patients with polycystic ovary syndrome: Association with PI3K signaling pathway

Polycystic ovary syndrome (PCOS) is a disease in which endocrine metabolic abnormalities coexist with reproductive system abnormalities, with the main clinical manifestations including abnormal menstruation, hirsutism, acne, infertility, and obesity, and it is also a high risk for the development of many pregnancy complications, gynecological malignancies and other diseases. Therefore, timely intervention to prevent the progression of PCOS is of great significance for improving the quality of life of most female patients. Insulin resistance (IR) is one of the most common endocrine disorders in PCOS patients, with approximately 75% of PCOS patients experiencing varying degrees of IR. It is now believed that it is mainly related to the PI3K signaling pathway. The role of autophagy and apoptosis of ovarian granulosa cells (GCs) in the pathogenesis of PCOS has also been gradually verified in recent years. Coincidentally, it also seems to be associated with the PI3K signaling pathway. Our aim is to review these relevant studies, to explore the association between the IR, cellular autophagy and apoptosis in PCOS patients and the PI3K pathway. We summarize some of the drug studies that have improved PCOS as well. We have also found that proteomics holds great promise in exploring the pathogenesis of PCOS, and we have published our views on this.

Key signalling pathways underlying the aetiology of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine condition characterised by a range of reproductive, endocrine, metabolic and psychological abnormalities. Reports estimate that around 10% of women of reproductive age are affected by PCOS, representing a significant prevalence worldwide, which poses a high economic health burden. As the origin of PCOS remains largely unknown, there is neither a cure nor mechanism-based treatments leaving patient management suboptimal and focused solely on symptomatic treatment. However, if the underlying mechanisms underpinning the development of PCOS were uncovered then this would pave the way for the development of new interventions for PCOS. Recently, there have been significant advances in our understanding of the underlying pathways likely involved in PCOS pathogenesis. Key insights include the potential involvement of androgens, insulin, anti-Müllerian hormone and transforming growth factor beta in the development of PCOS. This review will summarise the significant scientific discoveries on these factors that have enhanced our knowledge of the mechanisms involved in the development of PCOS and discuss the impact these insights may have in shaping the future development of effective strategies for women with PCOS.

Oxidative Stress as a Contributor to Insulin Resistance in the Skeletal Muscles of Mice with Polycystic Ovary Syndrome

Polycystic ovarian syndrome (PCOS) is a reproductive, endocrine, and metabolic disorder. Circulating markers of oxidative stress are abnormal in women with PCOS. There is a close relationship between oxidative stress and insulin resistance (IR). However, little information is available about oxidative stress in the skeletal muscles of those affected by PCOS. In this study, PCOS was induced in prepubertal C57BL/6J mice by injection with dehydroepiandrosterone. Oxidative stress biomarkers were then measured in both serum and skeletal muscles. The underlying mechanisms were investigated in C2C12 myotubes treated with testosterone (T). We discovered increased oxidative biomarkers, increased ROS production, and damaged insulin sensitivity in the skeletal muscles of mice with PCOS. High levels of T caused mitochondrial dysfunction and increased ROS levels through the androgen receptor (AR)-nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) signaling pathway in C2C12 cells. Treatment of C2C12 cells with an antioxidant N-acetylcysteine (NAC) decreased T-induced ROS production, improved mitochondrial function, and reversed IR. Administration of NAC to mice with PCOS improved insulin sensitivity in the skeletal muscles of the animals. Hyperandrogenism caused mitochondrial dysfunction and redox imbalance in the skeletal muscles of mice with PCOS. We discovered that oxidative stress contributed to skeletal muscle IR in PCOS. Reducing ROS levels may improve the insulin sensitivity of skeletal muscles in patients with PCOS.

Increased homocysteine regulated by androgen activates autophagy by suppressing the mammalian target of rapamycin pathway in the granulosa cells of polycystic ovary syndrome mice

The purpose of this study was to explore the potential molecular mechanisms of excess homocysteine in relation to autophagic activity in the ovarian tissue of polycystic ovarian syndrome (PCOS) with hyperandrogenism.A PCOS model was constructed using ICR mice. ELISA was used to detect the Hcy levels in the serum and ovarian tissues of PCOS model. The expression level of key enzymes (Methionine synthase and Betaine-homocysteine methyltransferase, MTR and BHMT) in homocysteine metabolism and autophagy-related proteins were detected in ovarian tissues and mouse granulosa cells (mGCs) that were treated with homocysteine, androgen, autophagy inhibitors or BHMT-expressing plasmid by western blot and immunohistochemistry. Electron microscope experiments were used to evaluate autophagosomes in Hcy-treated mGCs. The prenatally androgenized (PNA) PCOS mouse model showed hyperhomocysteinemia and hyperandrogenism. Homocysteine levels displayed a significant increase, while its metabolic enzymes levels were significantly decreased in ovarian tissues of PCOS mice and dihydrotestosterone (DHT)-stimulated mGCs. The LC3II and Beclin1 expression levels were increased and the P62 and p-mTOR levels were decreased in vivo in ovarian tissue from the PCOS mice. The in vitro data were similarly with the in vivo by stimulation of mGCs with DHT or homocysteine. These effects could be diminished by the autophagy inhibitor (MHY1485), androgen receptor antagonists (ARN509) or BHMT-expressing plasmid. Androgen increases homocysteine concentration by downregulating the key enzymes in homocysteine metabolism. And then Hcy promotes GCs autophagy via the mTOR signal pathway.

Hyperandrogenism and Polycystic ovary syndrome: Effects in pregnancy and offspring development

Polycystic ovary syndrome (PCOS) is one of the major endocrine disorders affecting women of reproductive age. Its etiology remains unclear. It is suggested that environmental factors, and particularly the intrauterine environment, play key roles in PCOS development. Besides the role of androgens in PCOS pathogenesis, exposure to endocrine disruptors, as is Bisphenol A, could also contribute to its development. Although PCOS is considered one of the leading causes of ovarian infertility, many PCOS patients can get pregnant. Some of them by natural conception and others by assisted reproductive technique treatments. As hyperandrogenism (one of PCOS main features) affects ovarian and uterine functions, PCOS women, despite reaching pregnancy, could present high-risk pregnancies, including implantation failure, an increased risk of gestational diabetes, preeclampsia, and preterm birth. Moreover, hyperandrogenism may also be maintained in these women during pregnancy. Therefore, as an altered uterine milieu, including hormonal imbalance, could affect the developing organisms, monitoring these patients throughout pregnancy and their offspring development is highly relevant. The present review focuses on the impact of androgenism and PCOS on fertility issues and pregnancy-related outcomes and offspring development. The evidence suggests that the increased risk of pregnancy complications and adverse offspring outcomes of PCOS women would be due to the factors involved in the syndrome pathogenesis and the related co-morbidities. A better understanding of the involved mechanisms is still needed and could contribute to a better management of these women and their offspring. This article is categorized under: Reproductive System Diseases > Molecular and Cellular Physiology Reproductive System Diseases > Environmental Factors.

Endoplasmic Reticulum Stress: A New Research Direction for Polycystic Ovary Syndrome?

Polycystic ovary syndrome (PCOS) is one of the most common gynecological endocrine disorders, with sporadic ovulation, excessive androgens, and polycystic ovarian changes as the main clinical manifestations. Due to the high heterogeneity of its clinical manifestations, the discussion on its pathogenesis has not been unified. Current research has found that genetic factors, hyperandrogenism, chronic inflammation and oxidative stress, insulin resistance, and obesity are strongly associated with PCOS. Recently, when studying the specific mechanisms of the abovementioned factors in PCOS, the biological response process of endoplasmic reticulum stress (ERS) has gradually come to researchers' attention, and several studies have confirmed the involvement of ERS in the pathogenesis of PCOS and the improvement of a series of pathological manifestations of PCOS after the application of ERS inhibitors, which may be a new entry point for the treatment of PCOS. In this article, we review the relationship between ERS and various pathogenic factors of PCOS.

Current Perspectives on Nonalcoholic Fatty Liver Disease in Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most common reproductive, endocrine, and metabolic disorders in premenopausal women. Clinically, PCOS is mainly caused by androgen excess and ovarian dysfunction, manifested by anovulatory menstrual cycles, infertility, and hirsutism. In addition, PCOS increases the risk of insulin resistance, obesity, cardiovascular disease, anxiety and depression, dyslipidemia, and endometrial cancer. Nonalcoholic fatty liver disease (NAFLD) is defined as ≥5% fat accumulation in the liver in the absence of remaining secondary causes and has become one of the most common chronic liver diseases worldwide. The prevalence of NAFLD is significantly higher and more severe in women with PCOS, and its pathogenesis can be associated with various risk factors such as hyperandrogenemia, insulin resistance, obesity, chronic low-grade inflammation, and genetic factors. Although there is no definitive solution for the management of NAFLD in PCOS, some progress has been made. Lifestyle modification should be the basis of management, and drugs to improve metabolism, such as insulin sensitizers and glucagon-like peptide-1 agonists, may show better efficacy. Bariatric surgery may also be a treatment of NAFLD in obese women with PCOS. This paper reviews three aspects of prevalence, risk factors, and management, in order to better understand the current state of research on NAFLD in PCOS, to explore the pathogenesis of NAFLD in PCOS, and to encourage further research on the application of drugs in this field.

Polycystic ovarian syndrome: signs and feedback effects of hyperandrogenism and insulin resistance

Polycystic ovary syndrome (PCOS) is a disease whose diagnosis is based on the detection of hyperandrogenism (HA) and ovulatory dysfunction. Women with PCOS frequently develop insulin resistance (IR), which generates a metabolic condition that involves a decrease in the action of insulin at the cellular level and is linked to compensatory hyperinsulinemia (HI). In PCOS, the ovary remains sensitive to the action of insulin. Additionally, it has been observed that the main effect of insulin in the ovary is the stimulation of androgen synthesis, resulting in HA, one of the fundamental characteristics of the PCOS. In this sense, the excess of androgens favors the development of IR, thus perpetuating the cycle of IR-HI-HA, and therefore PCOS. Moreover, mitochondrial dysfunction is present in PCOS patients and is a common feature in both IR and HA. This review places electron transfer as a key element in HA and IR development, with emphasis on the relationship between androgen biosynthesis and mitochondrial function. Indeed, metformin has been involved in repair mitochondrial dysfunction, decrease of oxidative stress, reduction of androgens levels and the enhancing of insulin sensitivity. Therefore, we propose that treatment with metformin could decrease HI and consequently HA, restoring, at least in part, the metabolic and hormonal disorders of PCOS.

Polycystic ovary syndrome: Identification of novel and hub biomarkers in the autophagy-associated mRNA-miRNA-lncRNA network

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common metabolic and endocrine disorder prevalent among women of reproductive age. Recent studies show that autophagy participated in the pathogenesis of PCOS, including anovulation, hyperandrogenism, and metabolic disturbances. This study was designed to screen autophagy-related genes (ATGs) that may play a pivotal role in PCOS, providing potential biomarkers and identifying new molecular subgroups for therapeutic intervention.

METHODS

Gene expression profiles of the PCOS and control samples were obtained from the publicly available Gene Expression Omnibus database. The gene lists of ATGs from databases were integrated. Then, the weighted gene co-expression network analysis was conducted to obtain functional modules and construct a multifactorial co-expression network. Gene Ontology and KEGG pathway enrichment analyses were performed for further exploration of ATG's function in the key modules. Differentially expressed ATGs were identified and validated in external datasets with the Limma R package. To provide guidance on PCOS phenotyping, the dysfunction module consists of a co-expression network mapped to PCOS patients. A PCOS-Autophagy-related co-expression network was established using Cytoscape, followed by identifying molecular subgroups using the Limma R package. ps. RNA-sequencing analysis was used to confirm the differential expression of hub ATGs, and the diagnostic value of hub ATGs was assessed by receiver operating characteristic curve analysis.

RESULTS

Three modules (Brown, Turquoise, and Green) in GSE8157, three modules (Blue, Red, and Green) in GSE43264, and four modules (Blue, Green, Black, and Yellow) in GSE106724 were identified to be PCOS-related by WGCNA analysis. 29 ATGs were found to be the hub genes that strongly correlated with PCOS. These hub ATGs were mainly enriched in autophagy-related functions and pathways such as autophagy, endocytosis, apoptosis, and mTOR signaling pathways. The mRNA-miRNA-lncRNA multifactorial network was successfully constructed. And three new molecular subgroups were identified via the K-means algorithm.

DISCUSSION

We provide a novel insight into the mechanisms behind autophagy in PCOS. BRCA1, LDLR, MAP1B, hsa-miR-92b-3p, hsa-miR-20b-5p, and NEAT1 might play a considerably important role in PCOS dysfunction. As a result, new potential biomarkers can be evaluated for use in PCOS diagnosis and treatment in the future.

Dendrobium officinale polysaccharide ameliorates polycystic ovary syndrome via regulating butyrate dependent gut-brain-ovary axis mechanism

Research has shown that dendrobium officinale polysaccharide (DOP) can promote follicular development and inhibit the apoptosis of ovarian granular cells in PCOS rats. However, DOP cannot be absorbed directly by the stomach and small intestine but is degraded into short-chain fatty acids by gut microbiota in the large intestine and regulates the composition of gut microbiota. How DOP improved ovarian function in PCOS rats through the blood-brain barrier is unclear. In this study, we generated letrozole-induced PCOS rat models and studied the therapeutic effect and mechanism of DOP. 16S rRNA amplicon sequencing analysis, GC-MS short-chain fatty acid detection, and Gene Expression Omnibus database searching were conducted to screen the significantly changed pathways, and a series of experiments, such as enzyme-linked immunosorbent assay, RT-qPCR, Western blot, and immunohistochemistry, were performed. We found that DOP treatment could improve ovarian morphology and endocrine disorders, restore the normal estrus cycle, increase gut microbiota α diversity, and alter β diversity and enrichment of butyrate-producing bacterium in PCOS rats. In addition, compared with PCOS rats, those treated with DOP exhibited higher butyrate and polypeptide YY levels, possibly due to the regulation of G protein-coupled receptor 41 expression. These results indicated that DOP relieved the symptoms of PCOS rats which may be related to the mechanism of butyrate dependent gut-brain-ovary axis protection.

The regulatory effects of clomiphene and tamoxifen on mTOR and LC3-II expressions in relation to autophagy in experimental polycystic ovary syndrome (PCOS)

BACKGROUND

Polycystic ovary syndrome (PCOS) is a metabolic disease that causes infertility due to anovulation in women in reproductive age. It is known that clomiphene citrate (CC) and tamoxifen citrate (TMX) induce ovulation in women with PCOS. In this study, we aimed to investigate the effects of CC and TMX on the autophagy pathway in PCOS.

METHODS AND RESULTS

Experimental PCOS model was induced by letrozole (1 mg/kg) in rats by gavage for 21 days. After the last letrozole administration, rats were treated TMX (1 mg/kg) or CC (1 mg/kg) for 5 days. At the end of the experimental procedures, rats in all groups were sacrificed and ovarian tissues were removed. It was observed that mRNA and protein expressions of LC3-II were significantly higher in TMX and CC groups than control and PCOS groups (p < 0.05), while mRNA and protein expressions of mTOR in TMX and CC groups were found significantly lower than control and PCOS groups (p < 0.05).

CONCLUSIONS

In conclusion, present study suggests that TMX and CC induce autophagy in ovaries with PCOS. Autophagy is a promising target for understanding pathophysiology of this disease and for developing more effective and safe new protocols for the treatment of PCOS-related anovulation.

Autophagy in ovary and polycystic ovary syndrome: role, dispute and future perspective

Polycystic ovary syndrome (PCOS) is a unification of endocrine and metabolic disorders and has become immensely prevalent among women of fertile age. The prime organ affected in PCOS is the ovary and its distressed functioning elicits disturbed reproductive outcomes. In the ovary, macroautophagy/autophagy performs a pivotal role in directing the chain of events starting from oocytes origin until its fertilization. Recent discoveries demonstrate a significant role of autophagy in the pathogenesis of PCOS. Defective autophagy in the follicular cells during different stages of follicles is observed in the PCOS ovary. Exploring different autophagy pathways provides a platform for predicting the possible cause of altered ovarian physiology in PCOS. In this review, we have emphasized autophagy's role in governing follicular development under normal circumstances and in PCOS, including significant abnormalities associated with PCOS such as anovulation, hyperandrogenemia, metabolic disturbances, and related abnormality. So far, few studies have linked autophagy and PCOS and propose its essential role in PCOS progression. However, detailed knowledge in this area is lacking. Here we have summarized the latest knowledge related to autophagy associated with PCOS. This review's main objective is to provide a background of autophagy in the ovary, its possible connection with PCOS and suggested a novel proposal for future studies to aid a better understanding of PCOS pathogenesis.Abbreviations: AE: androgen excess; AF: antral follicle; AKT/PKB: AKT serine/threonine kinase; AMH: anti-Mullerian hormone; AMPK: AMP-activated protein kinase; ATG: autophagy-related; BCL2: BCL2 apoptosis regulator; BECN1: beclin 1; BMP: bone morphogenetic protein; CASP3: caspase 3; CL: corpus luteum; CYP17A1/P450C17: cytochrome P450 family 17 subfamily A member 1; CYP19A1: cytochrome P450 family 19 subfamily A member 1; DHEA: dehydroepiandrosterone; EH: endometrial hyperplasia; FF: follicular fluid; FOXO: forkhead box O; FSH: follicle stimulating hormone; GC: granulosa cell; GDF: growth differentiation factor; HA: hyperandrogenemia; HMGB1: high mobility group box 1; IGF1: insulin like growth factor 1; INS: insulin; IR: insulin resistance; LHCGR/LHR: luteinizing hormone/choriogonadotropin receptor; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MAPK/ERK: mitogen-activated protein kinase; MAPK8/JNK: mitogen-activated protein kinase 8; MTOR: mechanistic target of rapamycin kinase; MTORC: mechanistic target of rapamycin complex; NAFLD: nonalcoholic fatty liver disease; NFKB: nuclear factor kappa B; OLR1/LOX-1: oxidized low density lipoprotein receptor 1; oxLDL: oxidized low-density lipoproteins; PA: palmitic acid; PCOS: polycystic ovary syndrome; PF: primary follicle; PGC: primordial germ cell; PI3K: phosphoinositide 3-kinase; PMF: primordial follicle; ROS: reactive oxygen species; RP: resting pool; SIRT1: sirtuin 1; SQSTM1/p62: sequestosome 1; T2DM: type 2 diabetes mellitus; TC: theca cell; TUG1: taurine up-regulated 1.

Let-7e modulates the proliferation and the autophagy of human granulosa cells by suppressing p21 signaling pathway in polycystic ovary syndrome without hyperandrogenism

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in reproductive-aged women, and its pathogenesis is still under debate. Recent studies suggest crucial roles for microRNAs (miRNAs) in PCOS development. The let-7 family miRNAs constitute the most abundant miRNAs in human granulosa cells (GCs), and plays an important role in follicular development. However, research on the let-7e implications of the non-hyperandrogenic (non-HA) phenotype remains unclear. This study aimed at determining the role of let-7e in the progression of PCOS. We performed quantitative real-time PCR to examine the levels of let-7e in fifty-two non-HA PCOS patients and fifty-two controls. A receiver operating characteristic (ROC) curve were used to reveal the diagnostic value of let-7e in non-HA PCOS. Using an immortalized human granulosa cell line, KGN, we investigated the influence of let-7e on cell proliferation and autophagy. Our data substantiated the expression of let-7e was significantly increased in non-HA PCOS group, and associated with an increased antral follicle count. The ROC curve indicated a major separation between non-HA PCOS group and the control group. Let-7e knockdown suppressed cell proliferation and enhanced cell autophagy by activating p21 pathway. Conversely, let-7e overexpression promoted cell proliferation and inhibited cell autophagy by suppressing p21 pathway. Our results indicate that increased let-7e levels in non-HA PCOS GCs may contribute to excessive follicular activation and growth, thereby involving in the pathogenesis of PCOS. Let-7e may thus be a potential therapeutic target in non-HA PCOS.

Magnolia officinalis Ameliorates Dehydroepiandrosterone-Induced Polycystic Ovary Syndrome in Rats

Background: Polycystic ovary syndrome (PCOS) is a prevalent reproductive and metabolic disorder. Insulin resistance (IR) is highly associated with PCOS and aggravates its symptoms. Thiazolidinediones (TZDs), as insulin sensitizing agents, are PPARγ agonists that improve many of the symptoms of PCOS. The Magnolia officinalis extract (MOE) is a natural peroxisome proliferator activated receptor gamma (PPARγ) agonist that improves insulin sensitivity in experimental models. Objectives: Using a dehydroepiandrosterone (DHEA)-induced rat model of PCOS and IR, this study aimed to explore both the potential beneficial effects and the molecular mechanisms of action of MOE. Methods: Post-pubertal female Sprague Dawley rats were subcutaneously injected daily with DHEA (6 mg/100 g body weight) dissolved in sesame oil for 28 days (n = 30). Age- and weight-matched control rats received only sesame oil (n = 12). Afterward, 16 of the DHEA-injected rats, along with five control rats, were sacrificed for blood and tissue collection. The 14 remaining DHEA-injected rats received either treatment of 30 days of oral MOE (500 mg/kg) dissolved in dimethyl sulfoxide (DMSO) (n = 7), or oral DMSO only (n = 7). Meanwhile, the remaining control rats (n = 7) continued to receive daily oral DMSO for 30 days. At the end of the treatments, the rats were sacrificed for blood and tissue collection. Results: After 28 days, the DHEA-treated rats exhibited an increase in body weight as compared to controls (P < 0.05). DHEA injection induced a PCOS phenotype as evident by a statistically significant (P < 0.05) elevated serum luteinizing hormone (LH), and an increased number of cystically dilated follicles with thicker granulosa compared to controls. PCOS rats showed a statistically significant rise in fasting insulin with an increased homeostatic model assessment index of insulin resistance (HOMA-IR) as compared to controls (P < 0.05). Compared to the control group, PCOS rats had a statistically significant lower ovarian protein expression of PPARγ, insulin receptor substrate 1 (IRS1), and protein kinase B (Akt) by Western Blot (P < 0.05). Conversely, the PCOS group showed an increased mammalian target of rapamycin (mTOR) pathway activity as evident by an increase in the fraction of phosphorylated mTOR to total mTOR compared to the control group (P < 0.05). When treated for 30 days with oral MOE (500 mg/kg), the PCOS rats showed a statistically significant decrease in body weight and serum LH levels as compared to the non-treated PCOS rats (P < 0.05). The number of cystically dilated follicles in the MOE-treated PCOS rats was significantly reduced compared to the non-treated PCOS rats. In the MOE-treated PCOS rats, the ovarian protein expression of PPARγ, IRS1, and Akt was significantly increased, while the p-mTOR/mTOR expression was decreased compared to the non-treated PCOS group (P < 0.05). Conclusions: According to our results, the MOE ameliorated the DHEA-induced PCOS phenotype histologically, hormonally, and metabolically. Fundamentally, this explores the elusive pathophysiologic association between IR and PCOS by targeting pathways common to both disorders.

Mitochondria in Sex Hormone-Induced Disorder of Energy Metabolism in Males and Females

Androgens have a complex role in the regulation of insulin sensitivity in the pathogenesis of type 2 diabetes. In male subjects, a reduction in androgens increases the risk for insulin resistance, which is improved by androgen injections. However, in female subjects with polycystic ovary syndrome (PCOS), androgen excess becomes a risk factor for insulin resistance. The exact mechanism underlying the complex activities of androgens remains unknown. In this review, a hormone synergy-based view is proposed for understanding this complexity. Mitochondrial overactivation by substrate influx is a mechanism of insulin resistance in obesity. This concept may apply to the androgen-induced insulin resistance in PCOS. Androgens and estrogens both exhibit activities in the induction of mitochondrial oxidative phosphorylation. The two hormones may synergize in mitochondria to induce overproduction of ATP. ATP surplus in the pancreatic β-cells and α-cells causes excess secretion of insulin and glucagon, respectively, leading to peripheral insulin resistance in the early phase of type 2 diabetes. In the skeletal muscle and liver, the ATP surplus contributes to insulin resistance through suppression of AMPK and activation of mTOR. Consistent ATP surplus leads to mitochondrial dysfunction as a consequence of mitophagy inhibition, which provides a potential mechanism for mitochondrial dysfunction in β-cells and brown adipocytes in PCOS. The hormone synergy-based view provides a basis for the overactivation and dysfunction of mitochondria in PCOS-associated type 2 diabetes. The molecular mechanism for the synergy is discussed in this review with a focus on transcriptional regulation. This view suggests a unifying mechanism for the distinct metabolic roles of androgens in the control of insulin action in men with hypogonadism and women with PCOS.

How to Screen and Prevent Metabolic Syndrome in Patients of PCOS Early: Implications From Metabolomics

BACKGROUND

Polycystic ovary syndrome (PCOS) is a complex reproductive endocrine disorder. And metabolic syndrome (MS) is an important bridge for PCOS patients to develop other diseases, such as diabetes and coronary heart disease. Our aim was to study the potential metabolic characteristics of PCOS-MS and identify sensitive biomarkers so as to provide targets for clinical screening, diagnosis, and treatment.

METHODS

In this study, 44 PCOS patients with MS, 34 PCOS patients without MS, and 32 healthy controls were studied. Plasma samples of subjects were tested by ultraperformance liquid chromatography (UPLC) system combined with LTQ-orbi-trap mass spectrometry. The changes of metabolic characteristics from PCOS to PCOS-MS were systematically analyzed. Correlations between differential metabolites and clinical characteristics of PCOS-MS were assessed. Differential metabolites with high correlation were further evaluated by the receiver operating characteristic (ROC) curve to identify their sensitivity as screening indicators.

RESULTS

There were significant differences in general characteristics, reproductive hormone, and metabolic parameters in the PCOS-MS group when compared with the PCOS group and healthy controls. We found 40 differential metabolites which were involved in 23 pathways when compared with the PCOS group. The metabolic network further reflected the metabolic environment, including the interaction between metabolic pathways, modules, enzymes, reactions, and metabolites. In the correlation analysis, there were 11 differential metabolites whose correlation coefficient with clinical parameters was greater than 0.4, which were expected to be taken as biomarkers for clinical diagnosis. Besides, these 11 differential metabolites were assessed by ROC, and the areas under curve (AUCs) were all greater than 0.7, with a good sensitivity. Furthermore, combinational metabolic biomarkers, such as glutamic acid + leucine + phenylalanine and carnitine C 4: 0 + carnitine C18:1 + carnitine C5:0 were expected to be sensitive combinational biomarkers in clinical practice.

CONCLUSION

Our study provides a new insight to understand the pathogenesis mechanism, and the discriminating metabolites may help screen high-risk of MS in patients with PCOS and provide sensitive biomarkers for clinical diagnosis.

Correlation Analysis Between Ovarian Reserve and Thyroid Hormone Levels in Infertile Women of Reproductive Age

OBJECTIVE

To analyze the correlation between ovarian reserve and thyroid function in women with infertility.

METHODS

Retrospective analysis of the data of 496 infertility patients who visited the clinic between January 2019 and December 2020. According to the TSH level, it is grouped into <2.5 mIU/L, 2.5~4.0mIU/L and ≥4.0 mIU/L or according to the positive/negative thyroid autoimmune antibody. The relationship was assessed through the ovarian reserve, thyroid function, and anti-Müllerian hormone (AMH) levels in infertile patients. On the other hand, the patients are divided into groups according to age (≤29 years old, 30-34 years old and ≥35 years old), basic FSH (<10 IU/L and ≥10 IU/L), and AMH levels. The ovarian reserve was evaluated through the AMH and the antral follicle count (AFC).

RESULTS

The average age of the patients was 30.31 ± 4.50 years old, and the average AMH level was 5.13 ± 4.30 ng/mL. 3.63% (18/496) of patients had abnormal TSH levels (normal: 0.35-5.5 mIU/L), the positive rate of thyroid peroxidase antibody (TPOAb) was 14.52% (72/496), the positive rate of anti-thyroglobulin antibody (TgAb) was 16.94% (84/496), and the positive rate of TPOAb and TgAb was 10.48% (52/496). After grouping according to TSH level or thyroid autoimmune antibody positive/negative grouping, the analysis found that there was no statistical significance in age, AMH level and basic FSH level among the groups (P>0.05). There were no significant differences in the levels of TSH, FT3, and FT4 among different ages, AMH, and FSH levels (P>0.05).

CONCLUSION

There is no significant correlation between ovarian reserve and thyroid function in infertile women.

Novel mechanisms underlying anti-polycystic ovary like syndrome effects of electroacupuncture in rats: suppressing SREBP1 to mitigate insulin resistance, mitochondrial dysfunction and oxidative stress

Background

Acupuncture, a therapy of traditional Chinese medicine, is confirmed to exert the therapeutic action on polycystic ovary syndrome (PCOS). However, the detailed therapeutic mechanisms of acupuncture in PCOS remain ambiguous. In this study, we further investigated whether electroacupuncture (EA) alleviated PCOS-like symptoms in rats via regulating a metabolic regulator, sterol regulatory element binding protein-1 (SREBP1).

Methods

The PCOS-like rat model was built by hypodermic injection with dehydroepiandrosterone (DHEA). The rats were subjected to EA intervention (ST29 and SP6 acupuncture points) for 5 weeks. Primary granulosa cells were isolated from control and PCOS-like rats for evaluating insulin resistance, mitochondrial dysfunction and oxidative stress in vitro.

Results

The expression of SREBP1 was increased in PCOS-like rats, which was suppressed by EA treatment. In addition, lentivirus-mediated overexpression of SREBP1 restrained EA treatment-induced improvement in pathological changes, serum hormone levels and insulin resistance in rats. In addition, overexpression of SREBP1 repressed insulin-stimulated phosphorylation of insulin receptor β (IR) and AKT in primary granulosa cells. Moreover, upregulation of SREBP1 further exacerbated mitochondrial dysfunction and oxidative stress in granulosa cells isolated from PCOS-like rats. Mechanically, EA treatment suppressed SREBP1 expression through inducing the activation of AMP-activated protein kinase (AMPK) signaling pathway in PCOS-like rats.

Conclusion

EA intervention alleviated PCOS-like symptoms in rats via improving IR, mitochondrial dysfunction and oxidative stress through regulating SREBP1, a lipid metabolism regulator. Our findings illuminate the novel protective mechanisms of EA in the treatment of PCOS.

Effect of fish oil and telmisartan on dehydroepiandrosterone-induced polycystic ovarian syndrome in rats: The role of oxidative stress, transforming growth factor beta-1, and nuclear factor kappa B

Our aim was to explore the effect of telmisartan and/or fish oil on dehydroepiandrosterone (DHEA)-induced PCOS in rats. Sixty female rats were divided into six equal groups as follows: Control; DHEA-induced PCOS; DHEA + Telmisartan; DHEA + Fish oil; DHEA + Carboxymethyl cellulose; and DHEA + Telmisartan +Fish oil group. Plasma sex hormones, anthropometric measurements, and the glycemic indices were measured. Tissue oxidative stress parameters and the proinflammatory cytokines were assessed. The ovaries were subjected to histopathological and electron microscopic examination. Telmisartan and/or fish oil induced significant improvement of insulin resistance with amelioration of oxidative stress and inflammation compared to PCOS group. Also, telmisartan and/or fish oil restored the hormonal levels and the anthropometric measurements to the normal values. This was significant with telmisartan/fish oil combination compared to the use of each of these agents alone. In conclusion, this combination may represent a promising hope for amelioration of PCOS.

Electroacupuncture alleviates polycystic ovary syndrome-like symptoms through improving insulin resistance, mitochondrial dysfunction, and endoplasmic reticulum stress via enhancing autophagy in rats

BACKGROUND

Electroacupuncture (EA), a treatment derived from traditional Chinese medicine, can effectively improve hyperandrogenism and insulin resistance in patients with polycystic ovary syndrome (PCOS), however, its underlying mechanisms remain obscure. This study aimed to investigate whether EA could mitigate PCOS-like symptoms in rats by regulating autophagy.

METHODS

A rat model of PCOS-like symptoms was established by subcutaneous injection with dehydroepiandrosterone (DHEA), and then EA treatment at acupoints (ST29 and SP6) was carried out for 5 weeks. To inhibit autophagy in rats, intraperitoneal injection with 0.5 mg/kg 3-MA (an autophagy inhibitor) was performed at 30 min before each EA treatment.

RESULTS

EA intervention alleviated PCOS-like symptoms in rats, which was partly counteracted by the combination with 3-MA. Moreover, DHEA-exposure-induced deficient autophagy in skeletal muscle was improved by EA treatment. EA-mediated improvements in insulin resistance, mitochondrial dysfunction, and endoplasmic reticulum (ER) stress in PCOS-like rats were counteracted by 3-MA pretreatment. Mechanically, EA attenuated autophagy deficiency-mediated insulin resistance in PCOS-like rats via inactivating mTOR/4E-BP1 signaling pathway.

CONCLUSIONS

Taken together, our findings indicate that EA treatment ameliorates insulin resistance, mitochondrial dysfunction, and ER stress through enhancing autophagy in a PCOS-like rat model. Our study provides novel insight into the mechanisms underlying the treatment of EA in PCOS, which offers more theoretic foundation for its clinical application.

Mitochondrial Dysfunction in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most common female reproductive metabolisms. It is an endocrine disease that affects reproductive women and often exhibits with hyperandrogenemia, insulin resistance (IR), low inflammation, and an increased risk of type 2 diabetes mellitus, metabolic syndrome, and cardiovascular events such as hypertension and dyslipidemia in patients. However, the molecular mechanism of PCOS is still unclear. Recently, an increasing number of studies have shown that the oxidative stress induced by mitochondrial dysfunction has negative effects on IR, lipid metabolism, and follicular development, suggesting that mitochondrial dysfunction plays an essential role in the development of PCOS. Abnormal mitochondrial DNA copy number in patients with PCOS, and mitochondrial gene mutations, has been the focus of research in recent years, and functional mitochondrial diseases have been gradually accepted as a related factor in PCOS. This review is intended to summarize and discuss previous and recent studies and findings on the connections between mitochondrial dysfunction and PCOS.

Metabolic dysfunction in polycystic ovary syndrome: Pathogenic role of androgen excess and potential therapeutic strategies

Background

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy among reproductive age women. Although its cardinal manifestations include hyperandrogenism, oligo/anovulation, and/or polycystic ovarian morphology, PCOS women often display also notable metabolic comorbidities. An array of pathogenic mechanisms have been implicated in the etiology of this heterogeneous endocrine disorder; hyperandrogenism at various developmental periods is proposed as a major driver of the metabolic and reproductive perturbations associated with PCOS. However, the current understanding of the pathophysiology of PCOS-associated metabolic disease is incomplete, and therapeutic strategies used to manage this syndrome's metabolic complications remain limited.

Scope of review

This study is a systematic review of the potential etiopathogenic mechanisms of metabolic dysfunction frequently associated with PCOS, with special emphasis on the metabolic impact of androgen excess on different metabolic tissues and the brain. We also briefly summarize the therapeutic approaches currently available to manage metabolic perturbations linked to PCOS, highlighting current weaknesses and future directions.

Major conclusions

Androgen excess plays a prominent role in the development of metabolic disturbances associated with PCOS, with a discernible impact on key peripheral metabolic tissues, including the adipose, liver, pancreas, and muscle, and very prominently the brain, contributing to the constellation of metabolic complications of PCOS, from obesity to insulin resistance. However, the current understanding of the pathogenic roles of hyperandrogenism in metabolic dysfunction of PCOS and the underlying mechanisms remain largely incomplete. In addition, the development of more efficient, even personalized therapeutic strategies for the metabolic management of PCOS patients persists as an unmet need that will certainly benefit from a better comprehension of the molecular basis of this heterogeneous syndrome.

Effects of Vitamin D Deficiency on Proliferation and Autophagy of Ovarian and Liver Tissues in a Rat Model of Polycystic Ovary Syndrome

Aim: We aimed to examine the alterations of the insulin signaling pathway, autophagy, nitrative stress and the effect of vitamin D supplementation in the liver and ovaries of vitamin D deficient hyperandrogenic rats. Methods: Female Wistar rats received eight weeks of transdermal testosterone treatment and lived on a low vitamin D diet (D–T+). Vitamin D supplementation was achieved by oral administration of vitamin D3 (D+T+). Sham-treated (D+T–) and vitamin D deficient animals (D–T–) served as controls. (N = 10–12 per group). Results: D–T+ animals showed decreased LC3 II levels in the liver and increased p-Akt/Akt and p-eNOS/eNOS ratios with decreased insulin receptor staining in the ovaries. Vitamin D supplementation prevented the increase of Akt phosphorylation in the ovaries. Vitamin D deficiency itself also led to decreased LC3 II levels in the liver and decreased insulin receptor staining in the ovaries. D–T+ group showed no increase in nitrotyrosine staining; however, the ovaries of D–T– rats and the liver of D+T+ animals showed increased staining intensity. Conclusion: Vitamin D deficiency itself might lead to disrupted ovarian maturation and autophagy malfunction in the liver. Preventing Akt phosphorylation may contribute to the beneficial effect of vitamin D treatment on ovarian function in hyperandrogenism.

Human steroid sulfatase enhances aerobic glycolysis through induction of HIF1α and glycolytic enzymes

Human steroid sulfatase (STS) has been linked with poor prognosis in steroid-associated tumors and represents an important clinical target in cancers, yet the mechanism of STS-induced carcinogenesis remains unclear. To correlate STS with cancer metabolism, we determined the effects of STS on aerobic glycolysis. STS overexpression increased cellular levels of lactic acid, the final product of aerobic glycolysis. Moreover, STS suppressed the oxygen consumption rate (OCR), which represents mitochondrial respiration. Inhibition of STS by the specific inhibitor STX064 recovered STS-induced OCR repression and lactic acid over-production. DHEA, but not DHEA-S, suppressed the OCR level and enhanced lactic acid production. To understand the molecular mechanism of STS-induced cancer metabolism, we measured the expression of glycolytic enzymes hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2), which was highly upregulated by STS and DHEA at both protein and mRNA levels. HIF1α is a key mediator of aerobic glycolysis, and STS enhanced HIF1α promoter activity, mRNA expression, and protein expression. Down-regulation of HIF1α by siRNA suppressed the HK2 and PKM2 expression induced by both STS and DHEA. HIF1α siRNA also recovered the OCR repression and lactic acid over-production induced by both STS and DHEA. To explore the mechanism in vivo, we produced transgenic mice overexpressing STS and found that STS expression was particularly enhanced in the lung. Consistent with our in vitro results, the expression of HIF1α, HK2, and PKM2 was also increased in mouse lung tissues. In conclusion, we suggest that STS may induce aerobic glycolysis through enhancing HIF1α expression.

Nontargeted metabolomic analysis of skeletal muscle in a dehydroepiandrosterone-induced mouse model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy and an important metabolic disorder in women of reproductive age. Insulin resistance (IR) is one of its most important clinical features in patients with PCOS. Androgen excess-induced mitochondrial dysfunction contributes to skeletal muscle IR in dehydroepiandrosterone (DHEA)-induced PCOS mice. The effect of androgen excess on the skeletal muscle, however, is incompletely characterized. A nontargeted metabolomics approach was thus applied to analyze the metabolites in skeletal muscle of DHEA-induced PCOS mice. Data from metabolomic analysis revealed the significant changes in 32 metabolites and the marked impact of five metabolic pathways. ATP production was also found to be significantly reduced in skeletal muscle of DHEA mice. Combined with the quantification of type I and II myofibers and lipid measurement in the skeletal muscle of the mice, the results from the present study supported the role of mitochondrial impairment rather than lipid accumulation in the pathogenesis of skeletal muscle IR in DHEA-induced PCOS mice. In summary, we show here for the first time the profile of the metabolites in the skeletal muscle of DHEA-induced PCOS mice which exhibit IR. The work would help better understand the pathology of skeletal muscle IR in PCOS.

Autophagy as an emerging target in cardiorenal metabolic disease: From pathophysiology to management

Although advances in medical technology and health care have improved the early diagnosis and management for cardiorenal metabolic disorders, the prevalence of obesity, insulin resistance, diabetes, hypertension, dyslipidemia, and kidney disease remains high. Findings from numerous population-based studies, clinical trials, and experimental evidence have consolidated a number of theories for the pathogenesis of cardiorenal metabolic anomalies including resistance to the metabolic action of insulin, abnormal glucose and lipid metabolism, oxidative and nitrosative stress, endoplasmic reticulum (ER) stress, apoptosis, mitochondrial damage, and inflammation. Accumulating evidence has recently suggested a pivotal role for proteotoxicity, the unfavorable effects of poor protein quality control, in the pathophysiology of metabolic dysregulation and related cardiovascular complications. The ubiquitin-proteasome system (UPS) and autophagy-lysosomal pathways, two major although distinct cellular clearance machineries, govern protein quality control by degradation and clearance of long-lived or damaged proteins and organelles. Ample evidence has depicted an important role for protein quality control, particularly autophagy, in the maintenance of metabolic homeostasis. To this end, autophagy offers promising targets for novel strategies to prevent and treat cardiorenal metabolic diseases. Targeting autophagy using pharmacological or natural agents exhibits exciting new strategies for the growing problem of cardiorenal metabolic disorders.