New insights into the genic and metabolic characteristics of induced pluripotent stem cells from polycystic ovary syndrome women

Induced Pluripotent Stem Cells as a Possible Approach for Exploring the Pathophysiology of Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine condition among women with pleiotropic sequelae possessing reproductive, metabolic, and psychological characteristics. Although the exact origin of PCOS is elusive, it is known to be a complex multigenic disorder with a genetic, epigenetic, and environmental background. However, the pathogenesis of PCOS, and the role of genetic variants in increasing the risk of the condition, are still unknown due to the lack of an appropriate study model. Since the debut of induced pluripotent stem cell (iPSC) technology, the ability of reprogrammed somatic cells to self-renew and their potential for multidirectional differentiation have made them excellent tools to study different disease mechanisms. Recently, researchers have succeeded in establishing human in vitro PCOS disease models utilizing iPSC lines from heterogeneous PCOS patient groups (iPSCPCOS). The current review sets out to summarize, for the first time, our current knowledge of the implications and challenges of iPSC technology in comprehending PCOS pathogenesis and tissue-specific disease mechanisms. Additionally, we suggest that the analysis of polygenic risk prediction based on genome-wide association studies (GWAS) could, theoretically, be utilized when creating iPSC lines as an additional research tool to identify women who are genetically susceptible to PCOS. Taken together, iPSCPCOS may provide a new paradigm for the exploration of PCOS tissue-specific disease mechanisms.

Essential Role of Granulosa Cell Glucose and Lipid Metabolism on Oocytes and the Potential Metabolic Imbalance in Polycystic Ovary Syndrome

Granulosa cells are crucial for the establishment and maintenance of bidirectional communication among oocytes. Various intercellular material exchange modes, including paracrine and gap junction, are used between them to achieve the efficient delivery of granulosa cell structural components, energy substrates, and signaling molecules to oocytes. Glucose metabolism and lipid metabolism are two basic energy metabolism pathways in granulosa cells; these are involved in the normal development of oocytes. Pyruvate, produced by granulosa cell glycolysis, is an important energy substrate for oocyte development. Granulosa cells regulate changes in intrafollicular hormone levels through the processing of steroid hormones to control the development process of oocytes. This article reviews the material exchange between oocytes and granulosa cells and expounds the significance of granulosa cells in the development of oocytes through both glucose metabolism and lipid metabolism. In addition, we discuss the effects of glucose and lipid metabolism on oocytes under pathological conditions and explore its relationship to polycystic ovary syndrome (PCOS). A series of changes were found in the endogenous molecules and ncRNAs that are related to glucose and lipid metabolism in granulosa cells under PCOS conditions. These findings provide a new therapeutic target for patients with PCOS; additionally, there is potential for improving the fertility of patients with PCOS and the clinical outcomes of assisted reproduction.

Integrative Analysis of Core Genes and Biological Process Involved in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disordered disease, affecting the function of the ovaries in women of reproductive age. However, there are limited curative therapies for PCOS due to lack of reliable candidates. Hence, this study aimed to identify hub pathogenic genes and potential therapeutic targets for PCOS using bioinformatics tools. We obtained the expression profiles of 29 PCOS samples and 24 normal samples from three Gene Expression Omnibus (GEO) datasets. Then, the differentially expressed genes (DEGs) were screened, which were subjected to functional enrichment analyses. Moreover, we found 30 ferroptosis-related genes out of the 89 DEGs. Among the top 10 significant ferroptosis-related DEGs, 8 genes showed good predictive performance. We constructed interaction network of top three ferroptosis-related DEGs (SLC38A1, ACO1, DDIT3). Finally, real-time PCR was performed to test the relative expression of these genes. In conclusions, we have identified ferroptosis-related DEGs as core genes and potential therapeutic targets of PCOS based on comprehensive bioinformatics analysis. The findings are conducive to understanding of the pathogenesis of PCOS and paving the way towards curative therapies.

Therapeutic restoration of female reproductive and endocrine dysfunction using stem cells

Millions of women worldwide suffer from infertility associated with gynecologic disorders such as premature ovarian insufficiency, polycystic ovary syndrome, Asherman syndrome, endometriosis, preeclampsia, and fallopian tube obstruction. These disorders can lead to infertility and thereby affect the quality of life of the infertile couple because of their psychological impact and significant costs. In recent years, stem cell therapy has emerged as a therapeutic approach to repair or replace damaged tissues or organs. This review describes the recent development as well as the underlying mechanisms of stem cell therapy for a variety of female reproductive diseases, offering us new therapeutic options for the treatment of female reproductive and endocrine dysfunction.

Regenerative Medicine for Polycystic Ovary Syndrome: Stem Cell-Based Therapies and Brown Adipose Tissue Activation

Polycystic ovary syndrome (PCOS) is a pathological condition prevalent among women of reproductive age: it is associated with varied etiological factors (lifestyle, genetic, environmental…) and characterized by an increased polycystic morphology of the ovaries leading to disturbances in the menstrual cycle and its correlated infertility. Interconnections between PCOS, obesity, and insulin resistance have been recently investigated thoroughly in the scientific community; these findings directed PCOS therapies into unraveling possibilities to target insulin resistance and central adiposity as efficient treatment. On the other hand, brown adipose tissue is known to possess a thermogenic activity that increases lipolysis and directly attenuates fat deposition. Therefore, brown adipose tissue activation lands itself as a potential target for reducing obesity and its induced insulin resistance, subsequently rescuing PCOS phenotypes. In addition, regenerative medicine has proven efficacy in resolving PCOS-associated infertility and its metabolic symptoms. In particular, many stem/progenitor cells have been verified to possess the differentiation capacity into functional brown adipocytes. Thus, throughout this review, we will discuss the different brown adipose tissue activation strategies and stem-cell-based therapies applied to PCOS models and the possible combination of both therapeutic approaches to synergistically act on the activation of brown adipose tissue and attenuate PCOS-correlated infertility and retract the consequences of the metabolic syndrome on the physiological state of patients.

Stem Cells and Congenital Heart Disease: The Future Potential Clinical Therapy Beyond Current Treatment

Congenital heart disease (CHD) is the most common congenital anomaly in newborns. Current treatment for cyanotic CHD largely relies on the surgical intervention; however, significant morbidity and mortality for patients with CHD remain. Recent research to explore new avenues of treating CHD includes the utility of stem cells within the field. Stem cells have since been used to both model and potentially treat CHD. Most clinical applications to date have focused on hypoplastic left heart syndrome. Here, we examine the current role of stem cells in CHD and discuss future applications within the field.

Mitochondrial and glucose metabolic dysfunctions in granulosa cells induce impaired oocytes of polycystic ovary syndrome through Sirtuin 3

Mitochondrial function and glucose metabolism play important roles in bidirectional signaling between granulosa cells (GCs) and oocytes. However, the factors associated with mitochondrial function and glucose metabolism of GCs in polycystic ovary syndrome (PCOS) are poorly understood, and their potential downstream effects on oocyte quality are still unknown. The aim of this study was to investigate whether there are alterations in mitochondrial-related functions and glucose metabolism in ovarian GCs of women with PCOS and the role of Sirtuin 3 (SIRT3) in this process. Here, we demonstrated that women with PCOS undergoing in vitro fertilization and embryo transfer had significantly lower rates of metaphase II oocytes, two-pronuclear fertilization, cleavage, and day 3 good-quality embryos. Germinal vesicle- and metaphase I-stage oocytes from women with PCOS exhibited increased mitochondrial reactive oxygen species (ROS), decreased mitochondrial membrane potential, and downregulation of glucose-6-phosphate dehydrogenase. GCs from women with PCOS presented significant alterations in mitochondrial morphology, amount, and localization, decreased membrane potential, reduced adenosine triphosphate (ATP) synthesis, increased mitochondrial ROS and oxidative stress, and insufficient oxidative phosphorylation (OXPHOS) together with decreased glycolysis. SIRT3 expression was significantly decreased in GCs of PCOS patients, and knockdown of SIRT3 in KGN cells could mimic the alterations in mitochondrial functions and glucose metabolism in PCOS GCs. SIRT3 knockdown changed the acetylation status of NDUFS1, which might induce altered mitochondrial OXPHOS, the generation of mitochondrial ROS, and eventually defects in the cellular insulin signaling pathway. These findings suggest that SIRT3 deficiency in GCs of PCOS patients may contribute to mitochondrial dysfunction, elevated oxidative stress, and defects in glucose metabolism, which potentially induce impaired oocytes in PCOS.

At the crossroads of fertility and metabolism: the importance of AMPK-dependent signaling in female infertility associated with hyperandrogenism

STUDY QUESTION

What biological processes are linked to the signaling of the energy sensor 5'-AMP-activated protein kinase (AMPK) in mouse and human granulosa cells (GCs)?

SUMMARY ANSWER

The lack of α1AMPK in GCs impacted cell cycle, adhesion, lipid metabolism and induced a hyperandrogenic response.

WHAT IS KNOWN ALREADY

AMPK is expressed in the ovarian follicle, and its activation by pharmacological medications, such as metformin, inhibits the production of steroids. Polycystic ovary syndrome (PCOS) is responsible for infertility in approximately 5-20% of women of childbearing age and possible treatments include reducing body weight, improving lifestyle and the administration of a combination of drugs to improve insulin resistance, such as metformin.

STUDY DESIGN, SIZE, DURATION

AMPK signaling was evaluated by analyzing differential gene expression in immortalized human granulosa cells (KGNs) with and without silencing α1AMPK using CRISPR/Cas9. In vivo studies included the use of a α1AMPK knock-out mouse model to evaluate the role of α1AMPK in folliculogenesis and fertility. Expression of α1AMPK was evaluated in primary human granulosa-luteal cells retrieved from women undergoing IVF with and without a lean PCOS phenotype (i.e. BMI: 18-25 kg/m2).

PARTICIPANTS/MATERIALS, SETTING, METHODS

α1AMPK was disrupted in KGN cells and a transgenic mouse model. Cell viability, proliferation and metabolism were evaluated. Androgen production was evaluated by analyzing protein levels of relevant enzymes in the steroid pathway by western blots, and steroid levels obtained from in vitro and in vivo models by mass spectrometry. Differential gene expression in human GC was obtained by RNA sequencing. Analysis of in vivo murine folliculogenesis was performed by histology and immunochemistry, including evaluation of the anti-Müllerian hormone (AMH) marker. The α1AMPK gene expression was evaluated by quantitative RT-PCR in primary GCs obtained from women with the lean PCOS phenotype (n = 8) and without PCOS (n = 9).

MAIN RESULTS AND THE ROLE OF CHANCE

Silencing of α1AMPK in KGN increased cell proliferation (P < 0.05 versus control, n = 4), promoted the use of fatty acids over glucose, and induced a hyperandrogenic response resulting from upregulation of two of the enzymes involved in steroid production, namely 3β-hydroxysteroid dehydrogenase (3βHSD) and P450 side-chain cleavage enzyme (P450scc) (P < 0.05, n = 3). Female mice deficient in α1AMPK had a 30% decrease in their ovulation rate (P < 0.05, n = 7) and litter size, a hyperandrogenic response (P < 0.05, n = 7) with higher levels of 3βHSD and p450scc levels in the ovaries, and an increase in the population of antral follicles (P < 0.01, n = 10) compared to controls. Primary GCs from lean women with PCOS had lower α1AMPK mRNA expression levels than the control group (P < 0.05, n = 8-9).

LARGE SCALE DATA

The FastQ files and metadata were submitted to the European Nucleotide Archive (ENA) at EMBL-EBI under accession number PRJEB46048.

LIMITATIONS, REASONS FOR CAUTION

The human KGN is a not fully differentiated, transformed cell line. As such, to confirm the role of AMPK in GC and the PCOS phenotype, this model was compared to two others: an α1AMPK transgenic mouse model and primary differentiated granulosa-lutein cells from non-obese women undergoing IVF (with and without PCOS). A clear limitation is the small number of patients with PCOS utilized in this study and that the collection of human GCs was performed after hormonal stimulation.

WIDER IMPLICATIONS OF THE FINDINGS

Our results reveal that AMPK is directly involved in steroid production in human GCs. In addition, AMPK signaling was associated with other processes frequently reported as dysfunctional in PCOS models, such as cell adhesion, lipid metabolism and inflammation. Silencing of α1AMPK in KGN promoted folliculogenesis, with increases in AMH. Evaluating the expression of the α1AMPK subunit could be considered as a marker of interest in infertility cases related to hormonal imbalances and metabolic disorders, including PCOS.

STUDY FUNDING/COMPETING INTEREST(S)

This study was financially supported by the Institut National de la Recherche Agronomique (INRA) and the national programme « FERTiNERGY » funded by the French National Research Agency (ANR). The authors report no intellectual or financial conflicts of interest related to this work. R.K. is identified as personnel of the International Agency for Research on Cancer/World Health Organization. R.K. alone is responsible for the views expressed in this article and she does not necessarily represent the decisions, policy or views of the International Agency for Research on Cancer/World Health Organization.

TRIAL REGISTRATION NUMBER

N/A.

Dexmedetomidine Reverses Postoperative Spatial Memory Deficit by Targeting Surf1 and Cytochrome c

Anesthesia and surgery are associated with perioperative neurocognitive disorders (PND). Dexmedetomidine is known to improve PND in rats; however, little is known about the mechanisms. Male Sprague-Dawley rats were subjected to resection of the hepatic apex under propofol anesthesia to clinically mimic human abdominal surgery. The rats were divided into four groups: control group (C), anesthesia group (A), model group (M), and model + dex group (D). Cognitive function was evaluated with the Morris water maze (MWM). Neuronal morphology was observed with H&E staining, Nissl's staining and immunohistochemistry. Transcriptome analysis and quantitative real-time PCR were performed to investigate functional mitochondrial mRNA changes in the hippocampus. Protein levels were measured by Western blotting at 1, 3, and 7 days after surgery. Surgery-induced cognitive decline lasted for three days, but not seven days after surgery in the M group; however, rats in the D group were significantly improved by dexmedetomidine. No significant differences in the number of neurons were observed between the groups after surgery. Rats from the M group showed significantly greater expression levels of Iba-1 and GFAP compared with the C group and the D group. Rats in the M group demonstrated increased Surf1 and Cytochrome c expression on days 1 and 3, but not day 7; similar changes were not induced in rats in the D group. Dexmedetomidine appears to reverse surgery-induced behavior, mitigate the higher density of Iba-1 and GFAP, and downregulate the expression of Surf1 and Cytochrome c protein in the hippocampus of rats in a PND model.

Mitochondrial DNA 4977 bp Deletion in Peripheral Blood Is Associated With Polycystic Ovary Syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disorder worldwide. We aimed to examine the associations of two mitochondrial DNA (mtDNA) biomarkers in the peripheral blood, mtDNA copy number (CN), and mtDNA⁴⁹⁷⁷ deletion rate (DR), with PCOS in a clinical setting.

METHODS

We performed a study involving 263 women with PCOS and 326 age-matched controls between June 2015 and June 2019. The mtDNA CN and mtDNA⁴⁹⁷⁷ DR were measured using multiplex probe-based qPCR. The associations of the mtDNA CN and mtDNA⁴⁹⁷⁷ DR with the risk of PCOS were estimated using logistic regression.

RESULTS

Analysis of the associations between mtDNA biomarkers and PCOS indicate that the mtDNA CN (P = 0.003) and mtDNA⁴⁹⁷⁷ DR (P < 0.001) in PCOS patients were significantly higher than those in the controls. After adjusting for the body mass index, luteinizing hormone/follicle-stimulating hormone ratio, and testosterone level, only higher mtDNA⁴⁹⁷⁷ DR was associated with PCOS (odds ratio 1.053, 95% confidence interval 1.024 to 1.083; P < 0.001). The linear dose-response trends of the mtDNA⁴⁹⁷⁷ DR were also supported by the quartile analysis.

CONCLUSION

Multivariable models suggest that mtDNA⁴⁹⁷⁷ DR levels are strongly associated with PCOS and represent an independent risk factor for PCOS. Further investigation of the utility of mtDNA as a biomarker for PCOS is warranted.

Protein Lysine Acetylation in Ovarian Granulosa Cells Affects Metabolic Homeostasis and Clinical Presentations of Women With Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine disorders accompanied by obvious metabolic abnormalities. Lower-quality oocytes and embryos are often found in PCOS women during assisted reproductive technology treatment. However, there is still no clarity about the mechanism of ovarian metabolic disorders and the impact on oocyte maturation in PCOS. The aim of this study was to understand the potential effect of the posttranslational modification on ovarian metabolic homeostasis and oocyte development potential in women with PCOS. A quantitative analysis of acetylated proteomics in ovarian granulosa cells of PCOS and control groups was carried out by mass spectrometry. There was widespread lysine acetylation of proteins, of which 265 proteins had increased levels of acetylation and 68 proteins had decreased levels of acetylation in the PCOS group. Most notably, differentially acetylated proteins were significantly enriched in the metabolic pathways of glycolysis, fatty acid degradation, TCA cycle, tryptophan metabolism, and branched-chain amino acid degradation. Acetyl-CoA acetyltransferase 1 (ACAT1) was an enzyme central to these metabolic pathways with increased acetylation level in the PCOS group, and there was a negative correlation of ACAT1 acetylation levels in PCOS granulosa cells with oocyte quality and embryo development efficiency in the clinic. Lysine acetylation changes of key enzymes in PCOS granulosa cells might attenuate their activities and alter metabolic homeostasis of follicular microenvironment for oocyte maturation and embryo development.

Is there any association between vitamin D levels and polycystic ovary syndrome (PCOS) phenotypes?

Objective The aim of this study was to assess the serum vitamin D level in a retrospective study in women with polycystic ovary syndrome (PCOS), according to the different phenotypes of the disease. Subjects and methods In this retrospective study, the records of 351 infertile women who were diagnosed with PCOS were examined, and 200 of them were enrolled in the study randomly in 4 PCOS phenotypes. Fifty normal ovulatory women with the history of male factor were selected as the control group. Parameters, including age, infertility duration, body mass index (BMI), hormone profile, as well as the serum vitamin D level were compared among the 4 phenotypes, with the P-value ≤ 0.05 considered statistically significant. Results The findings showed a higher serum vitamin D level in the control group than in PCOS patients, which was statistically significant (P < 0.001). In addition, there was no significant difference in the serum vitamin D level among the four phenotypes of PCOS. Conclusions No significant difference was found in the serum vitamin D level of the different phenotypes of PCOS. Further studies with larger sample sizes are recommended to be done to establish the role of the serum vitamin D level in PCOS patients.

Polycystic ovary syndrome and mitochondrial dysfunction

Polycystic ovary syndrome (PCOS) is a prevalent hormonal disorder of premenopausal women worldwide and is characterized by reproductive, endocrine, and metabolic abnormalities. The clinical manifestations of PCOS include oligomenorrhea or amenorrhea, hyperandrogenism, ovarian polycystic changes, and infertility. Women with PCOS are at an increased risk of suffering from type 2 diabetes; me\tabolic syndrome; cardiovascular events, such as hypertension, dyslipidemia; gynecological diseases, including infertility, endometrial dysplasia, endometrial cancer, and ovarian malignant tumors; pregnancy complications, such as premature birth, low birthweight, and eclampsia; and emotional and mental disorders in the future. Although numerous studies have focused on PCOS, the underlying pathophysiological mechanisms of this disease remain unclear. Mitochondria play a key role in energy production, and mitochondrial dysfunction at the cellular level can affect systemic metabolic balance. The recent wide acceptance of functional mitochondrial disorders as a correlated factor of numerous diseases has led to the presupposition that abnormal mitochondrial metabolic markers are associated with PCOS. Studies conducted in the past few years have confirmed that increased oxidative stress is associated with the progression and related complications of PCOS and have proven the relationship between other mitochondrial dysfunctions and PCOS. Thus, this review aims to summarize and discuss previous and recent findings concerning the relationship between mitochondrial dysfunction and PCOS.