Suppression of p66Shc prevents hyperandrogenism-induced ovarian oxidative stress and fibrosis

LncPrep + 96kb inhibits ovarian fibrosis by upregulating prolyl oligopeptidase expression

LncPrep + 96kb is a long non‑coding RNA expressed in murine granulosa cells. The 2.2-kb fragment of lncPrep + 96kb inhibits aromatase expression and estrogen secretion in ovarian granulosa cells. In the present study, lncPrep + 96kb‑knockout (KO) mice were generated, and significant ovarian fibrosis and reduced female fertility through fertility monitoring and superovulation. The augmentation of ovarian fibrosis was observed by Sirius red staining and western blot and RT‑qPCR. Notably, lncPrep + 96kb was identified in conserved non‑coding sequences adjacent to the prolyl oligopeptidase (POP) gene. Furthermore, POP expression was shown to be reduced in lncPrep + 96kb‑KO mice, whereas overexpression of lncPrep + 96kb increased POP expression. Further studies revealed that POP regulated the expression levels of factors related to fibrosis, including matrix metalloproteinase 2 (MMP2), transforming growth factor β1 (TGF‑β1) and peroxisome proliferator activated receptor γ (PPAR‑γ). In conclusion, ovarian fibrosis was elevated in lncPrep + 96kb‑KO mice, and POP may act as a target of lncPrep + 96kb, which mediates ovarian fibrosis through the regulation of PPAR‑γ, MMP2 and TGF‑β1 expression.

The potential of low-intensity pulsed ultrasound to apply the long-term ovary protection from injury induced by 4-vinylcyclohexene diepoxide through inhibiting granulosa cell apoptosis

The potential of low-intensity pulsed ultrasound (LIPUS) in regulating ovarian function has been demonstrated; however, there is a lack of scientific evidence regarding the long-term efficacy of LIPUS in treating ovarian injury and understanding its regulatory mechanisms. In this study, 4-vinylcyclohexene diepoxide (VCD) was used to induce ovarian injury in rats, and LIPUS was applied to target the damaged ovarian tissues. The research aimed to investigate the long-term protective effect of LIPUS against ovum toxicity induced by VCD and elucidate the associated molecular mechanisms. During the experiment, HE staining was employed for observing the morphology and structure of the ovary, while protein sequencing was utilized for identifying and confirming the molecular mechanism through which LIPUS restores the damaged ovarian structure. The long-term effectiveness of LIPUS in protecting against ovarian injury was evaluated through ELISA, estrous cycle monitoring, fertility testing, and behavioral analysis. The results indicated that LIPUS effectively restored the structure of damaged ovaries. Both in vivo and in vitro studies revealed that this protective effect may be attributed to LIPUS inhibiting apoptosis of ovarian granulosa cells (GCs) by regulating Daxx-mediated ASK1/JNK signaling pathway. Subsequent functional tests demonstrated significant improvements in sex hormone secretion and regulation of estrous cycle within 6 cycles following LIPUS treatment. Additionally, there was a notable increase in offspring numbers after mating. Behavioral analysis revealed that LIPUS effectively alleviated menopausal symptoms resulting from ovarian injury including mood fluctuations, cognitive behavior changes, and reduced muscle excitability levels. These findings suggest that beneficial effects of LIPUS may help reduce VCD-induced ovarian damage with long-term efficacy.

p66shc exacerbates the progression of obstructive nephropathy through apoptosis, mitochondrial damage, and EMT

BACKGROUND

Many factors contribute to hydronephrosis, ultimately resulting in renal fibrosis and even deterioration of renal function. This study investigated the pathogenic role of p66shc, a redox-regulatory protein, in hydronephrosis-induced renal injury.

OBJECTIVE

This study focused on the mechanism of p66shc in renal fibrosis associated with obstructive nephropathy.

METHODS

The expression of p66shc was found in kidney samples from pediatric hydronephrosis patients. A complete unilateral ureteral obstruction (CUUO) model was established in neonatal mice to recapitulate hydronephrotic progression. Cell proliferation, apoptosis, reactive oxygen species (ROS), mitochondrial damage, and degree of epithelial-mesenchymal transition (EMT) in renal tubular epithelial cells were studied following p66shc silencing and overexpression. We also investigated the therapeutic effects of silencing p66shc in vivo and carried out RNA sequencing after overexpressing p66shc in cells.

RESULTS

p66shc inhibited renal tubular epithelial cell growth, exacerbated cell oxidative and mitochondrial damage, and promoted cell apoptosis and EMT. Silencing its expression in vivo could efficiently reduce renal fibrosis. Combined with RNA sequencing, we analyzed the potential molecular mechanisms of p66shc downstream.

CONCLUSION

p66shc enhances cell damage and the EMT process in obstructive nephropathy. Suppressing the expression of p66shc is one potential strategy for mitigating renal fibrotic progression.

Transcriptomic analysis of the effects exerted by curcumin on dihydrotestosterone-induced ovarian granulosa cells

Purpose

Hyperandrogenism is a leading cause of developmental retardation in ovarian granulosa cells. Previous studies have indicated that curcumin significantly improves follicular dysplasia, a characteristic of the polycystic ovary syndrome. Our purpose was to explore the signaling pathways which enable curcumin to protect the development of hyperandrogen-induced granulosa cells.

Methods

Ovarian granulosa cells treated with or without curcumin at different dihydrotestosterone (DHT) levels, were screened for cell viability, reactive oxygen species production, and apoptosis. RNA sequencing (transcriptome sequencing) was used to determine global gene expression in DHT-induced granulosa cells treated with curcumin.

Results

24 hours of combined curcumin and DHT treatment inhibited granulosa cell viability in a dose-dependent manner. Curcumin upregulated estrogen synthesis-related enzymes, downregulated lipid metabolism-related genes and the glucuronic acid process, inhibited androgen receptor (AR) activity, significantly improved cell viability, and corrected granulosa cell development. Gene set enrichment and genome transcriptome pathway analyses revealed the potential role played by curcumin in protecting granulosa cell development.

Conclusion

High androgen levels may disrupt steroid hormone synthesis and lipid metabolism pathways associated with granulosa cell development, thereby activating AR and inhibiting estrogen biosynthesis. Curcumin restores granulosa cell development by correcting abnormal steroid gene expression and disordered lipid fatty acid metabolism.

Oxidative stress and energy metabolism abnormalities in polycystic ovary syndrome: from mechanisms to therapeutic strategies

Polycystic ovary syndrome (PCOS), as a common endocrine and metabolic disorder, is often regarded as a primary cause of anovulatory infertility in women. The pathogenesis of PCOS is complex and influenced by multiple factors. Emerging evidence highlights that energy metabolism dysfunction and oxidative stress in granulosa cells (GCs) are pivotal contributors to aberrant follicular development and impaired fertility in PCOS patients. Mitochondrial dysfunction, increased oxidative stress, and disrupted glucose metabolism are frequently observed in individuals with PCOS, collectively leading to compromised oocyte quality. This review delves into the mechanisms linking oxidative stress and energy metabolism abnormalities in PCOS, analyzing their adverse effects on reproductive function. Furthermore, potential therapeutic strategies to mitigate oxidative stress and metabolic disturbances are proposed, providing a theoretical basis for advancing clinical management of PCOS.

METTL3 silencing inhibits ferroptosis to suppress ovarian fibrosis in PCOS by upregulating m6A modification of GPX4

Methyltransferase-like 3 (METTL3) is extensively reported to be involved in organ fibrosis. Ovarian fibrosis is a main characteristic of polycystic ovary syndrome (PCOS). However, the reaction mechanism of METTL3 in PCOS is poorly investigated. This paper was intended to reveal the role and the mechanism of METTL3 in PCOS. Animal and cell models of PCOS were induced by dehydroepiandrosterone (DHEA). H&E staining was performed to detect the pathological alterations in ovary tissues. Masson staining, immunofluorescence, along with western blot measured fibrosis both in vitro and in vivo. To evaluate estrous cycle, vaginal smear was performed. Lipid peroxidation and ferroptosis were evaluated by MDA assay kits, GSH assay kits, immunohistochemistry, Prussian blue staining and western blot. qRT-PCR and western blot were adopted to estimate METTL3 and GPX4 expression. The m6A and hormone secretion levels were respectively assessed by m6A RNA Methylation Quantitative Kit and corresponding kits. The interaction between METTL3 and GPX4 was testified by immunoprecipitation. The fibrosis and ferroptosis were aggravated and m6A and METTL3 expression were increased in ovarian tissues of DHEA-induced PCOS mice. METTL3 silencing alleviated pathological changes, affected hormone secretion level, and repressed fibrosis, lipid peroxidation and ferroptosis in the ovarian tissues of PCOS mice. In vitro, DHEA stimulation increased m6A and METTL3 expression and induced ferroptosis and fibrosis. METTL3 knockdown promoted GPX4 expression in DHEA-induced granulosa cells by m6A modification and restrained DHEA-induced fibrosis, lipid peroxidation and ferroptosis in granulosa cells via elevating GPX4. METTL3 silence inhibited ovarian fibrosis in PCOS, which was mediated through suppressing ferroptosis by upregulating GPX4 in m6A-dependent manner.

Resveratrol Enhances Antioxidant and Anti-Apoptotic Capacities in Chicken Primordial Germ Cells through m6A Methylation: A Preliminary Investigation

Avian primordial germ cells (PGCs) are essential in avian transgenic research, germplasm conservation, and disease resistance breeding. However, cultured PGCs are prone to fragmentation and apoptosis, regulated at transcriptional and translational levels, with N6-methyladenosine (m6A) being the most common mRNA modification. Resveratrol (RSV) is known for its antioxidant and anti-apoptotic properties, but its effects on PGCs and the underlying mechanisms are not well understood. This study shows that RSV supplementation in cultured PGCs improves cell morphology, significantly enhances total antioxidant capacity (p < 0.01), reduces malondialdehyde levels (p < 0.05), increases anti-apoptotic BCL2 expression, and decreases Caspase-9 expression (p < 0.05). Additionally, RSV upregulates the expression of m6A reader proteins YTHDF1 and YTHDF3 (p < 0.05). m6A methylation sequencing revealed changes in mRNA m6A levels after RSV treatment, identifying 6245 methylation sites, with 1223 unique to the control group and 798 unique to the RSV group. Combined analysis of m6A peaks and mRNA expression identified 65 mRNAs with significantly altered methylation and expression levels. Sixteen candidate genes were selected, and four were randomly chosen for RT-qPCR validation, showing results consistent with the transcriptome data. Notably, FAM129A and SFRP1 are closely related to apoptosis, indicating potential research value. Overall, our study reveals the protective effects and potential mechanisms of RSV on chicken PGCs, providing new insight into its use as a supplement in reproductive stem cell culture.

Genetic and Epigenetic Landscape for Drug Development in Polycystic Ovary Syndrome

The treatment of polycystic ovary syndrome (PCOS) faces challenges as all known treatments are merely symptomatic. The US Food and Drug Administration has not approved any drug specifically for treating PCOS. As the significance of genetics and epigenetics rises in drug development, their pivotal insights have greatly enhanced the efficacy and success of drug target discovery and validation, offering promise for guiding the advancement of PCOS treatments. In this context, we outline the genetic and epigenetic advancement in PCOS, which provide novel insights into the pathogenesis of this complex disease. We also delve into the prospective method for harnessing genetic and epigenetic strategies to identify potential drug targets and ensure target safety. Additionally, we shed light on the preliminary evidence and distinctive challenges associated with gene and epigenetic therapies in the context of PCOS.

Ovarian fibrosis: molecular mechanisms and potential therapeutic targets

Ovarian fibrosis, characterized by the excessive proliferation of ovarian fibroblasts and the accumulation of extracellular matrix (ECM), serves as one of the primary causes of ovarian dysfunction. Despite the critical role of ovarian fibrosis in maintaining the normal physiological function of the mammalian ovaries, research on this condition has been greatly underestimated, which leads to a lack of clinical treatment options for ovarian dysfunction caused by fibrosis. This review synthesizes recent research on the molecular mechanisms of ovarian fibrosis, encompassing TGF-β, extracellular matrix, inflammation, and other profibrotic factors contributing to abnormal ovarian fibrosis. Additionally, we summarize current treatment approaches for ovarian dysfunction targeting ovarian fibrosis, including antifibrotic drugs, stem cell transplantation, and exosomal therapies. The purpose of this review is to summarize the research progress on ovarian fibrosis and to propose potential therapeutic strategies targeting ovarian fibrosis for the treatment of ovarian dysfunction.

Replicating human characteristics: A promising animal model of central fatigue

Central fatigue is a common pathological state characterized by psychological loss of drive, lack of appetite, drowsiness, and decreased psychic alertness. The mechanism underlying central fatigue is still unclear, and there is no widely accepted successful animal model that fully represents human characteristics. We aimed to construct a more clinically relevant and comprehensive animal model of central fatigue. In this study, we utilized the Modified Multiple Platform Method (MMPM) combined with alternate-day fasting (ADF) to create the animal model. The model group rats are placed on a stationary water environment platform for sleep deprivation at a fixed time each day, and they were subjected to ADF treatment. On non-fasting days, the rats were allowed unrestricted access to food. This process was sustained over a period of 21 days. We evaluated the model using behavioral assessments such as open field test, elevated plus maze test, tail suspension test, Morris water maze test, grip strength test, and forced swimming test, as well as serum biochemical laboratory indices. Additionally, we conducted pathological observations of the hippocampus and quadriceps muscle tissues, transmission electron microscope observation of mitochondrial ultrastructure, and assessment of mitochondrial energy metabolism and oxidative stress-related markers. The results revealed that the model rats displayed emotional anomalies resembling symptoms of depression and anxiety, decreased exploratory behavior, decline in learning and memory function, and signs of skeletal muscle fatigue, successfully replicating human features of negative emotions, cognitive decline, and physical fatigue. Pathological damage and mitochondrial ultrastructural alterations were observed in the hippocampus and quadriceps muscle tissues, accompanied by abnormal mitochondrial energy metabolism and oxidative stress in the form of decreased ATP and increased ROS levels. In conclusion, our ADF+MMPM model comprehensively replicated the features of human central fatigue and is a promising platform for preclinical research. Furthermore, the pivotal role of mitochondrial energy metabolism and oxidative stress damage in the occurrence of central fatigue in the hippocampus and skeletal muscle tissues was corroborated.

Tenascin C activates the toll‑like receptor 4/NF‑κB signaling pathway to promote the development of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a globally prevalent gynecological disorder among women of childbearing age. The present study aimed to investigate the role of tenascin C (TNC) in PCOS and its potential mechanisms. Fasting blood glucose and serum insulin, the homeostasis model assessment of insulin resistance and the serum hormone levels were determined in PCOS rats. In addition, H&E staining was used for assessing pathology. In addition, the effects of TNC on oxidative stress and inflammation response in PCOS rat and cell models was assessed. Furthermore, the roles of TNC on KGN cell proliferation and apoptosis were determined employing EdU assay and flow cytometry. TLR4/NF‑κB pathway‑related proteins were measured using western blotting, immunofluorescence and immunohistochemistry. It was found that the mRNA and protein expression was upregulated in PCOS rats and in KGN cells induced by dihydrotestosterone (DHT). Knockdown of TNC relieved the pathological characteristics and the endocrine abnormalities of PCOS rats. Knockdown of TNC inhibited ovarian cell apoptosis, oxidative stress and inflammation in PCOS rats. Knockdown of TNC reversed the DHT‑induced reduction in cell proliferation and increase in apoptosis in KGN cells. Furthermore, knockdown of TNC alleviated oxidative stress and inflammatory responses induced by DHT in KGN cells. Additionally, knockdown of TNC inhibited the toll‑like receptor 4 (TLR4)/NF‑κB signaling pathway in PCOS rats and DHT‑treated KGN cells. In conclusion, knockdown of TNC could ameliorate PCOS in both rats and a cell model by inhibiting cell apoptosis, oxidative stress and inflammation via the suppression of the TLR4/NF‑κB signaling pathway.

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.

Mechanisms of probiotic modulation of ovarian sex hormone production and metabolism: a review

Sex hormones play a pivotal role in the growth and development of the skeletal, neurological, and reproductive systems. In women, the dysregulation of sex hormones can result in various health complications such as acne, hirsutism, and irregular menstruation. One of the most prevalent diseases associated with excess androgens is polycystic ovary syndrome with a hyperandrogenic phenotype. Probiotics have shown the potential to enhance the secretion of ovarian sex hormones. However, the underlying mechanism of action remains unclear. Furthermore, comprehensive reviews detailing how probiotics modulate ovarian sex hormones are scarce. This review seeks to shed light on the potential mechanisms through which probiotics influence the production of ovarian sex hormones. The role of probiotics across various biological axes, including the gut-ovarian, gut-brain-ovarian, gut-liver-ovarian, gut-pancreas-ovarian, and gut-fat-ovarian axes, with a focus on the direct impact of probiotics on the ovaries via the gut and their effects on brain gonadotropins is discussed. It is also proposed herein that probiotics can significantly influence the onset, progression, and complications of ovarian sex hormone abnormalities. In addition, this review provides a theoretical basis for the therapeutic application of probiotics in managing sex hormone-related health conditions.

Insights on the NF-κB system in polycystic ovary syndrome, attractive therapeutic targets

The nuclear factor κappa B (NF-κB) signaling plays a well-known function in inflammation and regulates a wide variety of biological processes. Low-grade chronic inflammation is gradually considered to be closely related to the pathogenesis of Polycystic ovary syndrome (PCOS). In this review, we provide an overview on the involvement of NF-κB in the progression of PCOS particularly, such as hyperandrogenemia, insulin resistance, cardiovascular diseases, and endometrial dysfunction. From a clinical perspective, progressive recognition of NF-κB pathway provides opportunities for therapeutic interventions aimed at inhibiting pathway-specific mechanisms. With the accumulation of basic experimental and clinical data, NF-κB signaling pathway was recognized as a therapeutic target. Although there have been no specific small molecule NF-κB inhibitors in PCOS, a plethora of natural and synthetic compound have emerged for the pharmacologic intervention of the pathway. The traditional herbs developed for NF-κB pathway have become increasingly popular in recent years. Abundant evidence elucidated that NF-κB inhibitors can significantly improve the symptoms of PCOS. Herein, we summarized evidence relating to how NF-κB pathway is involved in the development and progression of PCOS. Furthermore, we present an in-depth overview of NF-κB inhibitors for therapy interventions of PCOS. Taken together, the NF-κB signaling may be a futuristic treatment strategy for PCOS.

Single-Cell Atlas of Human Ovaries Reveals The Role Of The Pyroptotic Macrophage in Ovarian Aging

Female fecundity declines in a nonlinear manner with age during the reproductive years, even as ovulatory cycles continue, which reduces female fertility, disrupts metabolic homeostasis, and eventually induces various chronic diseases. Despite this, the aging-related cellular and molecular changes in human ovaries that occur during these reproductive years have not been elucidated. Here, single-cell RNA sequencing (scRNA-seq) of human ovaries is performed from different childbearing ages and reveals that the activation of the pyroptosis pathway increased with age, mainly in macrophages. The enrichment of pyroptotic macrophages leads to a switch from a tissue-resident macrophage (TRM)-involve immunoregulatory microenvironment in young ovaries to a pyroptotic monocyte-derived macrophage (MDM)-involved proinflammatory microenvironment in middle-aged ovaries. This remolded ovarian immuno-microenvironment further promotes stromal cell senescence and accelerated reproductive decline. This hypothesis is validated in a series of cell and animal experiments using GSDMD-KO mice. In conclusion, the work expands the current understanding of the ovarian aging process by illustrating a pyroptotic macrophage-involved immune mechanism, which has important implications for the development of novel strategies to delay senescence and promote reproductive health.

The Protective Effects of Curcumin against Renal Toxicity

Curcumin is a naturally polyphenolic compound used for hepatoprotective, thrombosuppressive, neuroprotective, cardioprotective, antineoplastic, antiproliferative, hypoglycemic, and antiarthritic effects. Kidney disease is a major public health problem associated with severe clinical complications worldwide. The protective effects of curcumin against nephrotoxicity have been evaluated in several experimental models. In this review, we discussed how curcumin exerts its protective effect against renal toxicity and also illustrated the mechanisms of action such as anti-inflammatory, antioxidant, regulating cell death, and anti-fibrotic. This provides new perspectives and directions for the clinical guidance and molecular mechanisms for the treatment of renal diseases by curcumin.

Signaling pathways and targeted therapeutic strategies for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age. Although promising strides have been made in the field of PCOS over the past decades, the distinct etiologies of this syndrome are not fully elucidated. Prenatal factors, genetic variation, epigenetic mechanisms, unhealthy lifestyles, and environmental toxins all contribute to the development of this intricate and highly heterogeneous metabolic, endocrine, reproductive, and psychological disorder. Moreover, interactions between androgen excess, insulin resistance, disruption to the hypothalamic-pituitary-ovary (HPO) axis, and obesity only make for a more complex picture. In this review, we investigate and summarize the related molecular mechanisms underlying PCOS pathogenesis from the perspective of the level of signaling pathways, including PI3K/Akt, TGF-β/Smads, Wnt/β-catenin, and Hippo/YAP. Additionally, this review provides an overview of prospective therapies, such as exosome therapy, gene therapy, and drugs based on traditional Chinese medicine (TCM) and natural compounds. By targeting these aberrant pathways, these interventions primarily alleviate inflammation, insulin resistance, androgen excess, and ovarian fibrosis, which are typical symptoms of PCOS. Overall, we hope that this paper will pave the way for better understanding and management of PCOS in the future.

Bromodomain-containing protein 4 activates androgen receptor transcription and promotes ovarian fibrosis in PCOS

Polycystic ovary syndrome (PCOS) is an endocrine disorder and the main cause of anovulatory infertility, in which persistent activation of androgen receptor (AR) due to aberrant acetylation modifications of transcription is a potential trigger; however, the precise mechanisms of AR activation are poorly understood. In this study, AR activation in dehydroepiandrosterone- and letrozole-induced rat PCOS ovaries coincided with a marked increase of a chromatin acetylation "reader" BRD4. Further bioinformatic analysis showed that the AR promoter contained highly conserved binding motifs of BRD4 and HIF-1α. BRD4 and HIF-1α inducibly bound to the histone 3/4 acetylation-modified AR promoter, while administration of a BRD4-selective inhibitor JQ1 reduced the binding and AR transcription and improved the adverse expression of the core fibrotic mediators in PCOS ovaries and DHT-treated granulosa cells. Our data indicate that BRD4 upregulation and the resultant AR transcriptional activation constitute an important regulatory pathway that promotes ovarian fibrosis in PCOS.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SIRT6 reduces the symptoms of premature ovarian failure and alleviates oxidative stress and apoptosis in granulosa cells by degrading p66SHC via H3K9AC

CONTEXT

Substantial evidence suggests that ovarian oxidative stress can result in severe ovarian dysfunction.

OBJECTIVE

The purpose of this article is to investigate the potential of SIRT6 in alleviating premature ovarian failure (POF) by inhibiting oxidative stress.

METHODS

To mimic POF, mice were administered daily subcutaneous injections of d-galactose. The levels of E2, FSH, LH, AMH, and progesterone in serum were measured, along with changes in follicles and SIRT6 levels. Mice were treated with the SIRT6 agonist MDL-800, SIRT6 levels, follicles, and aforementioned hormones were reassessed. The effects of MDL-800 on oxidative stress and apoptosis were subsequently identified. Primary granulosa cells were isolated from mice, and the effects of H2O2 and MDL-800 on cell viability, oxidative stress, SIRT6 level, and apoptosis were evaluated. In addition, the regulation of SIRT6 on H3K9AC/p66SHC was verified by examining changes in protein levels, promoter activity, and the reversal effects of p66SHC overexpression.

RESULTS

MDL-800 mitigated hormone fluctuations, reduced follicle depletion in ovarian tissue, and attenuated oxidative stress and apoptosis in mice. In vitro experiments demonstrated that MDL-800 enhanced the resilience of primary granulosa cells against H2O2, as evidenced by increased cell viability and reduced oxidative stress and apoptosis. Furthermore, SIRT6 was found to decrease H3K9AC and p66SHC levels, as well as attenuate p66SHC promoter activity. The protective effects of MDL-800 on cells were reversed upon p66SHC overexpression.

CONCLUSION

In summary, this study highlights that activation of SIRT6 can alleviate POF and reduce oxidative stress by degrading H3K9AC and suppressing p66Shc levels in granulosa cells.

Exercise-induced irisin improves follicular dysfunction by inhibiting IRE1α-TXNIP/ROS-NLRP3 pathway in PCOS

BACKGROUND

Excessive production of androgen drives oxidative stress (OS) and inflammasome activation in ovarian granulosa cells (GCs). Therefore, the induced follicular developmental disorder is the major cause of infertility in women with polycystic ovary syndrome (PCOS). Exercise-induced upregulation of irisin is capable of regulating metabolism by reducing OS and inflammation. Exercise has been shown to alleviate a range of PCOS symptoms, including maintaining a normal menstrual cycle, in several clinical trials.

METHODS

Female Sprague-Dawley (SD) rats and primary ovarian cells were treated with two different androgens, dehydroepiandrosterone (DHEA) and dihydrotestosterone (DHT), to simulate a hyperandrogenic environment, followed by eight weeks of exercise training and irisin intervention. The levels of reactive oxygen species (ROS), tissue inflammation and fibrosis were examined using hematoxylin and eosin (H&E) staining, western blot, quantitative real-time PCR (qRT-PCR), dichlorofluorescein diacetate (DCF-DA) probe detection, immunofluorescence staining, immunohistochemistry, and Sirius red staining.

RESULTS

Exercise for eight weeks improved polycystic ovarian morphology and decreased the levels of inflammation, OS, and fibrosis in PCOS rats. Hyperandrogen increased ROS production in ovarian cells by inducing endoplasmic reticulum stress (ERS) and activating the inositol-requiring enzyme 1α (IRE1α)-thioredoxin-interacting protein (TXNIP)/ROS-NOD-like receptor family pyrin domain containing 3 (NLRP3) signaling pathway, further enhancing the levels of inflammation. Irisin suppressed the expression of IRE1α and its downstream targets, thus improving the ovarian dysfunction of PCOS rats induced by hyperandrogen.

CONCLUSION

Exercise can alleviate various phenotypes of PCOS rats induced by DHEA, and its therapeutic effect may be mediated by secreting beneficial myokines. IRE1α may be an important target of irisin for reducing OS and inflammation, thereby improving ovarian fibrosis.

Oxidative stress gene expression, DNA methylation, and gut microbiota interaction trigger Crohn's disease: a multi-omics Mendelian randomization study

BACKGROUND

Oxidative stress (OS) is a key pathophysiological mechanism in Crohn's disease (CD). OS-related genes can be affected by environmental factors, intestinal inflammation, gut microbiota, and epigenetic changes. However, the role of OS as a potential CD etiological factor or triggering factor is unknown, as differentially expressed OS genes in CD can be either a cause or a subsequent change of intestinal inflammation. Herein, we used a multi-omics summary data-based Mendelian randomization (SMR) approach to identify putative causal effects and underlying mechanisms of OS genes in CD.

METHODS

OS-related genes were extracted from the GeneCards database. Intestinal transcriptome datasets were collected from the Gene Expression Omnibus (GEO) database and meta-analyzed to identify differentially expressed genes (DEGs) related to OS in CD. Integration analyses of the largest CD genome-wide association study (GWAS) summaries with expression quantitative trait loci (eQTLs) and DNA methylation QTLs (mQTLs) from the blood were performed using SMR methods to prioritize putative blood OS genes and their regulatory elements associated with CD risk. Up-to-date intestinal eQTLs and fecal microbial QTLs (mbQTLs) were integrated to uncover potential interactions between host OS gene expression and gut microbiota through SMR and colocalization analysis. Two additional Mendelian randomization (MR) methods were used as sensitivity analyses. Putative results were validated in an independent multi-omics cohort from the First Affiliated Hospital of Sun Yat-sen University (FAH-SYS).

RESULTS

A meta-analysis from six datasets identified 438 OS-related DEGs enriched in intestinal enterocytes in CD from 817 OS-related genes. Five genes from blood tissue were prioritized as candidate CD-causal genes using three-step SMR methods: BAD, SHC1, STAT3, MUC1, and GPX3. Furthermore, SMR analysis also identified five putative intestinal genes, three of which were involved in gene-microbiota interactions through colocalization analysis: MUC1, CD40, and PRKAB1. Validation results showed that 88.79% of DEGs were replicated in the FAH-SYS cohort. Associations between pairs of MUC1-Bacillus aciditolerans and PRKAB1-Escherichia coli in the FAH-SYS cohort were consistent with eQTL-mbQTL colocalization.

CONCLUSIONS

This multi-omics integration study highlighted that OS genes causal to CD are regulated by DNA methylation and host-microbiota interactions. This provides evidence for future targeted functional research aimed at developing suitable therapeutic interventions and disease prevention.

1,25-Dihydroxyvitamin D3 alleviates hyperandrogen-induced ferroptosis in KGN cells

PURPOSE

Hyperandrogenism, one of the most frequent causes of anovulation in women, increases the risk of metabolic disorders in patients with polycystic ovary syndrome (PCOS). Ferroptosis, characterized by iron-dependent lipid peroxidation, has provided new insight into the progression of PCOS. 1,25-dihydroxyvitamin D3 (1,25D3) may play a role in reproduction because its receptor, VDR, which contributes to the inhibition of oxidative stress, is primarily located in the nuclei of granulosa cells. This study has therefore investigated whether 1,25D3 and hyperandrogenism affect granulosa-like tumor cells (KGN cells) through ferroptosis.

METHODS

KGN cells were treated with dehydroepiandrosterone (DHEA) or pretreated with 1,25D3. Cell viability was evaluated with the cell counting kit-8 (CCK-8) assay. The mRNA and protein expression levels of ferroptosis-related molecules, including glutathione peroxidase 4 (GPX4), solute carrier family 7 member (SLC7A11), and long-chain acyl-CoA synthetase 4 (ACSL4), were assessed via qRT-PCR and western blot. The concentration of malondialdehyde (MDA) was measured by ELISA. The rates of reactive oxygen species (ROS) production and lipid peroxidation were assessed via photometric methods.

RESULTS

Decreased cell viability, suppression of GPX4 and SLC7A11 expression, increased expression of ACSL4, elevated levels of MDA, accumulation of ROS, and increased lipid peroxidation, which are changes representative of ferroptosis, were observed in KGN cells after treatment with DHEA. Pretreatment with 1,25D3 in KGN cells significantly prevented these changes.

CONCLUSIONS

Our findings demonstrate that 1,25D3 attenuates hyperandrogen-induced ferroptosis of KGN cells. This finding might lead to new insights into the pathophysiology and therapy of PCOS and provides new evidence for the treatment of PCOS with 1,25D3.

Regulation of SIRT1 in Ovarian Function: PCOS Treatment

The sirtuin family, a group of NAD+-dependent class 3 histone deacetylases (HDACs), was extensively studied initially as a group of longevity genes that are activated in caloric restriction and act in concert with nicotinamide adenine dinucleotides to extend the lifespan. Subsequent studies have found that sirtuins are involved in various physiological processes, including cell proliferation, apoptosis, cell cycle progression, and insulin signaling, and they have been extensively studied as cancer genes. In recent years, it has been found that caloric restriction increases ovarian reserves, suggesting that sirtuins may play a regulatory role in reproductive capacity, and interest in the sirtuin family has continued to increase. The purpose of this paper is to summarize the existing studies and analyze the role and mechanism of SIRT1, a member of the sirtuin family, in regulating ovarian function. Research and review on the positive regulation of SIRT1 in ovarian function and its therapeutic effect on PCOS syndrome.

Advancements in lead therapeutic phytochemicals polycystic ovary syndrome: A review

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases in women of reproductive age and features complex pathological symptoms and mechanisms. Existing medical treatments have, to some extent, alleviated the deterioration of PCOS. However, these strategies only temporarily control symptoms, with a few side effects and no preventive effect. Phytochemicals extracted from medicinal herbs and plants are vital for discovering novel drugs. In recent years, many kinds of research have proven that phytochemicals isolated from traditional Chinese medicine (TCM) and medicinal plants show significant potential in preventing, alleviating, and treating PCOS. Nevertheless, compared to the abundance of experimental literature and minimal specific-topic reviews related to PCOS, there is a lack of systematic reviews to summarize these advancements in this promising field. Under this background, we systematically document the progress of bioactive phytochemicals from TCM and medicinal plants in treating PCOS, including flavonoids, polyphenols, and alkaloids. According to the literature, these valuable phytochemicals demonstrated therapeutic effects on PCOS supported by in vivo and in vitro experiments, mainly depending on anti-inflammatory, antioxidation, improvement of hormone disorder and insulin resistance (IR), and alleviation of hyperinsulinemia. Based on the current progress, future research directions should emphasize 1) exploring bioactive phytochemicals that potentially mediate bone metabolism for the treatment of PCOS; 2) improving unsatisfactory bioavailability by using advanced drug delivery systems such as nanoparticles and antibody-conjugated drugs, as well as a chemical modification; 3) conducting in-depth research on the pathogenesis of PCOS to potentially impact the gut microbiota and its metabolites in the evolution of PCOS; 4) revealing the pharmacological effects of these bioactive phytochemicals on PCOS at the genetic level; and 5) exploring the hypothetical and unprecedented functions in regulating PCOS by serving as proteolysis-targeting chimeras and molecular glues compared with traditional small molecule drugs. In brief, this review aims to provide detailed mechanisms of these bioactive phytochemicals and hopefully practical and reliable insight into clinical applications concerning PCOS.

Moderate Aerobic Exercise Regulates Follicular Dysfunction by Initiating Brain-Derived Neurotrophic Factor (BDNF)-Mediated Anti-Apoptotic Signaling Pathways in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder among women. Moderate aerobic exercise intervention is considered an initial treatment strategy for managing PCOS. Brain-derived neurotrophic factor (BDNF) is an important molecular mediator and a beneficial response to exercise. We aimed to investigate the expression pattern and underlying molecular mechanisms of this neurotrophic factor during follicle development in ovarian tissues. The PCOS model was established by subcutaneous injection of 60 mg/kg dehydroepiandrosterone (DHEA) into the neck of Sprague Dawley rats for 35 consecutive days. PCOS rats then received aerobic exercise for 8 weeks. Body/ovarian weight and peripheral serum hormone levels were observed. Immunohistochemistry combined with Western blot analysis and fluorescence quantitative polymerase chain reaction were used to detect the changes in BDNF-TrkB/p75NTR pathway, apoptosis, and inflammatory factors. We show that moderate aerobic exercise not only reverses the PCOS phenotype but also activates the BDNF-TrkB pathway and initiates downstream targets. p-TrkB upregulates and phosphorylates phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) to inhibit apoptosis. In addition, aerobic exercise therapy reduces the high expression of p75NTR in the ovarian tissue of PCOS rats and initiates the anti-apoptotic effect from the downstream pathway of NF-κB/JNK. Our in vitro results state that treatment with BDNF ameliorated dihydrotestosterone (DHT)-induced granulosa cells (GCs) apoptosis by provoking p-TrkB activation and upregulating the PI3K/AKT pathway. The present study suggests that moderate aerobic exercise regulates follicular dysfunction in PCOS-like rats. One possible mechanism is to initiate the BDNF-mediated anti-apoptotic signaling pathway.

The role of Sirtuin 1 in the pathophysiology of polycystic ovary syndrome

Polycystic ovarian syndrome (PCOS) is the most common multifactor heterogeneous endocrine and metabolic disease in women of childbearing age. PCOS is a group of clinical syndromes characterized by reproductive disorders, metabolic disorders, and mental health problems that seriously impact the physical and mental health of patients. At present, new studies suggest that human evolution leads to the body changes and the surrounding environment mismatch adaptation, but the understanding of the disease is still insufficient, the pathogenesis is still unclear. Sirtuin 1 (SIRT1), a member of the Sirtuin family, is expressed in various cells and plays a crucial role in cell energy conversion and physiological metabolism. Pathophysiological processes such as cell proliferation and apoptosis, autophagy, metabolism, inflammation, antioxidant stress and insulin resistance play a crucial role. Moreover, SIRT1 participates in the pathophysiological processes of oxidative stress, autophagy, ovulation disturbance and insulin resistance, which may be a vital link in the occurrence of PCOS. Hence, the study of the role of SIRT1 in the pathogenesis of PCOS and related complications will contribute to a more thorough understanding of the pathogenesis of PCOS and supply a basis for the treatment of patients.

Curcumin Inhibits Hyperandrogen-Induced IRE1α-XBP1 Pathway Activation by Activating the PI3K/AKT Signaling in Ovarian Granulosa Cells of PCOS Model Rats

Background

Hyperandrogenism is a common characteristic of polycystic ovary syndrome (PCOS). Long-term, continuous exposure to hyperandrogenic environments may cause excessive endoplasmic reticulum (ER) stress in ovarian granulosa cells (GCs). Curcumin is a polyphenol extracted from turmeric rhizomes which has several pharmacological effects that may benefit patients with PCOS. To explore whether curcumin can inhibit hyperandrogen-induced ER stress in ovarian GCs of PCOS rats and to elucidate the possible underlying mechanisms.

Methods

We developed PCOS model rats by exposure to hyperandrogenic conditions and divided the rats into control, PCOS, and PCOS+curcumin (200 mg/kg, for 8 weeks) groups. The levels of ER stress-related proteins and PI3K/AKT phosphorylation were measured in the ovarian tissue of all experimental groups by real-time quantitative PCR, western blotting, immunohistochemistry, and immunofluorescence. Subsequent in vitro analysis on primary cultured GCs was performed to confirm the influence of curcumin on ER stress inhibition by immunofluorescence and western blotting.

Results

Curcumin protects GCs from hyperandrogen-induced apoptosis in PCOS model rats by inhibiting the ER stress-related IRE1α-XBP1 pathway and activating the PI3K/AKT signaling pathway.

Conclusions

These observations indicate that curcumin might be a safe and useful supplement for PCOS patients.

Rhamnocitrin Attenuates Ovarian Fibrosis in Rats with Letrozole-Induced Experimental Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine-related cause of infertility in women and has an unknown etiology. Studies have shown that rhamnocitrin (Rha) exhibits positive effects on the reproductive system. This study investigated Rha's antifibrotic effects on PCOS rats and revealed its underlying mechanisms. Female SD rats were randomized into 4 groups (n = 8, each); the control group received tea oil by intraperitoneal injection and 1% w/v CMC by oral gavage; the PCOS group received letrozole (1 mg/kg); the PCOS+Rha group received letrozole and Rha (5 mg/kg); the PCOS+Met group received letrozole and Met (265 mg/kg) for 21 days. At the study end, Rha treatment restored letrozole-induced alterations in the relative ovarian weights, body weight, and relative weights of uterine and visceral adipose tissues. Histological observation showed that Rha ameliorates ovarian structure and fibrosis in PCOS. Administration of Rha reduced letrozole-induced metabolic dysfunction by ameliorating the levels of TC, TG, and HDL-C in the PCOS rats. Rha treatment also modulated the serum levels of sex hormones, which decreased T, E2, and LH and increased FSH in PCOS rats. In addition, Rha treatment modulated insulin resistance and increased gene expression of antioxidant enzymes (Cat, Sod2, Gpx3, Mgst1, Prdx3, Gsta4, Gsr, and Sod1) in the ovaries of the PCOS rats. Finally, Rha treatment appeared to increase the activity of PPAR-γ and inhibit the TGF-β1/Smad pathway in the ovaries of the PCOS rats. Our findings suggest that Rha significantly ameliorated metabolic disturbances and ovarian fibrosis in the PCOS rats. Rha perhaps is an effective compound for preventing ovarian fibrosis in the future.

Melatonin alleviates hydrogen peroxide induced oxidative damage in MC3T3-E1 cells and promotes osteogenesis by activating SIRT1

Oxidative stress is an important contributor to the development of osteoporosis. Melatonin, an indoleamine secreted by the pineal gland, has antioxidant properties. This study aims to explore whether melatonin can promote bone formation and elucidate the mechanisms underlying this process. In this study, we used an in vitro hydrogen peroxide (H₂O₂)-induced oxidative stress model in MC3T3-E1 cells and an in vivo ovariectomized osteoporotic bone defect model in rats to explore the protective effects of melatonin against osteoporotic bone defects along with the mechanism underlying these effects. We found that melatonin significantly increased alkaline phosphatase activity, mineralization capacity, and the expression of BMP2, RUNX2, and OPN in MC3T3-E1 cells treated with H₂O₂. Furthermore, melatonin was found to activate SIRT1, SIRT3 and inhibit p66Shc, reduce the intracellular reactive oxygen species levels, stabilize mitochondria, reduce malondialdehyde levels, increase superoxide dismutase activity, and reduce apoptosis in MC3T3-E1 cells treated with H₂O₂. Intriguingly, these effects could be reversed by the SIRT1 inhibitor EX527. In vivo experiments confirmed that melatonin improves the microstructure and bone mineral density of the distal femoral bone trabecula and promotes bone formation. Meanwhile, melatonin activated SIRT1, inhibited p66Shc and increased SIRT3 expression. Taken together, our findings showed that melatonin can restrain oxidative damage in MC3T3-E1 cells and promote osteogenesis by activating SIRT1 which regulate the activity of SIRT3 and inhibit the expression of p66Shc, suggesting that melatonin could be a potential therapeutic agent for osteoporosis-related bone metabolic diseases.

Dihydrotestosterone through blockade of TGF-β/Smad signaling mediates the anti-fibrosis effect under hypoxia in canine Sertoli cells

The hypoxic microenvironment of cryptorchidism is an important factor to induce the impairment of the structure and function of Sertoli cells and thus lead to spermatogenesis loss or tumorigenesis. Dihydrotestosterone (DHT), as a potent nonaromatizable 5α-reduced androgen, has both positive and negative effect on pathological fibrosis process. However, it is still unknown whether DHT can regulate hypoxia-induced fibrosis of Sertoli cells. Herein, in this study, we evaluate the DHT level, two 5α-reductase isoforms, 5α-red1 and 5α-red2, as well as HIF-1α expression pattern in canine cryptorchidism and contralateral normal testis. Results showed that the abdominal testes presented low DHT levels and 5α-red1 and 5α-red2 expression, while significantly higher HIF-1α expression and ECM production compared with the scrotum. Moreover, we established a hypoxia-induced fibrosis model in canine Sertoli cells induced by cobalt chloride (CoCl₂), and found that DHT inhibited the fibrosis of Sertoli cells in a dose-dependent manner. Meanwhile, DHT interfered with the TGF-β signaling by reducing the expression of TGF-βRI and TGF-βRII and inhibiting the expression and phosphorylation of Smad2 and Smad3, while flutamide (androgen receptor inhibitor) inhibited these effects of DHT. Furthermore, use of LY2109761 (TGF-β receptor type I/II inhibitor) to interfere with the TGF-β/Smad pathway showed a similar effect with DHT suppression of the fibrosis in Sertoli cells. Our research data demonstrated that cryptorchidism is located in a hypoxic and DHT deficiency microenvironment. Moreover, supplementing DHT can alleviate the fibrosis process of Sertoli cells caused by hypoxia, which is associated with AR regulating the inhibition of TGF-β/Smad signaling.

Salidroside alleviates oxidative stress and apoptosis via AMPK/Nrf2 pathway in DHT-induced human granulosa cell line KGN

In the past few years, emerging evidence established persistent oxidative stress to be a key player in the pathogenesis of polycystic ovary syndrome (PCOS). Particularly, it damages the function of granulosa cells, and thus hinders the development of follicles. The present study aimed to explore and establish the protective effects of salidroside on dihydrotestosterone (DHT)-induced Granulosa-like tumor cell line (KGN), mediated via antioxidant mechanisms. The study assessed the positive effects of salidroside on DHT-induced apoptosis, reactive oxygen species (ROS) accumulation, damage of antioxidant capacity, and mitochondrial membrane potential depolarization. Interestingly, salidroside partly reversed DHT mediated effects, via stimulation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and the downstream antioxidant proteins heme oxygenase-1(HO-1) and quinine oxidoreductase 1(NQO1). Additionally, the knockdown of Nrf2 partly moderated the antioxidant and anti-apoptosis effects of salidroside in DHT-treated KGN cells. Mechanistically, AMP-activated protein kinase (AMPK) was identified to be the upstream signaling involved in salidroside-induced Nrf2 activation, as silencing of AMPK partly prevented the upregulation of Nrf2 and the downstream proteins HO-1 and NQO1. Altogether, the present study is the first to effectively demonstrate the inhibitory effect of salidroside on DHT-stimulated oxidative stress and apoptosis in KGN cells, which was dependent on Nrf2 activation that involved AMPK.

Microcystin-leucine arginine (MC-LR) induces mouse ovarian inflammation by promoting granulosa cells to produce inflammatory cytokine via activation of cGAS-STING signaling

Early experimental studies have demonstrated that microcystin-leucine arginine (MC-LR) is able to induce multiple organ damage. Female reproductive disorders caused by MC-LR have attracted increased attention in recent years. However, the underlying mechanisms of female reproductive malfunctions are not yet fully understood. Our previous study confirmed that MC-LR could enter mice ovary, induce apoptosis of ovarian granulosa cell and lead to follicular atresia. Research shows that ovary inflammation is positively related to the decline of female reproductive function. This study was aimed to find out the relationship between inflammation response and ovarian injury caused by MC-LR. MC-LR were administrated at 0, 7.5, 22.5 and 45 µg/kg for two weeks by intraperitoneal injection in female BALB/c mice. Histopathological analysis of ovary was performed. We found that MC-LR exposure induced inflammation response and fibrosis in ovary. In the present study, we observed that MC-LR could enter ovary and was mainly distributed in mGCs (mouse ovarian granulosa cells), but not in the theca-interstitial cells. We isolated and cultured mGCs with different concentrations of MC-LR at 0, 0.01, 0.1, 1 and 10 µM. MC-LR exposure caused mitochondrial DNA (mtDNA) leakage which was detected by qPCR andimmunofluorescence staining. Subsequently, mtDNA leakage activated cGAS-STING signaling, leading to elevated production of inflammatory cytokines TNF-α in mGCs.Diffusion of TNF-α in ovary resulted in inflammatory cell infiltration and interstitial cell proliferation. Ovarian inflammation provides a new perspective to explore the underlying mechanisms associated with MC-LR-induced female reproductive dysfunction.

Curcumin in Combination with Aerobic Exercise Improves Follicular Dysfunction via Inhibition of the Hyperandrogen-Induced IRE1α/XBP1 Endoplasmic Reticulum Stress Pathway in PCOS-Like Rats

Combining diet with exercise can improve health and performance. Exercise can reduce androgen excess and insulin resistance (IR) in polycystic ovary syndrome (PCOS) patients. Curcumin is also presumed to improve the follicle development disorder. Here, we investigated the effects of a combination therapy of oral intake of curcumin and exercise on hyperandrogen-induced endoplasmic reticulum (ER) stress and ovarian granulosa cell (GC) apoptosis in rats with PCOS. We generated a PCOS model via continuous dehydroepiandrosterone subcutaneous injection into the necks of Sprague Dawley rats for 35 days. PCOS-like rats then received curcumin treatment combined with aerobic (treadmill) exercise for 8 weeks. We found that compared to control rats, the ovarian tissue and ovarian GCs of hyperandrogen-induced PCOS rats showed increased levels of ER stress-related genes and proteins. Hyperandrogen-induced ovarian GC apoptosis, which was mediated by excessive ER stress and unfolded protein response (UPR) activation, could cause follicle development disorders. Both curcumin gavage and aerobic exercise improved ovarian function via inhibiting the hyperandrogen-activated ER stress IRE1α-XBP1 pathway. Dihydrotestosterone- (DHT-) induced ER stress was mitigated by curcumin/irisin or 4μ8C (an ER stress inhibitor) in primary GC culture. In this in vitro model, the strongly expressed follicular development-related genes Ar, Cyp11α1, and Cyp19α1 were also downregulated.

Posttranslational modifications in pathogenesis of PCOS

Polycystic ovary syndrome (PCOS) is a lifelong reproductive, metabolic, and psychiatric disorder that affects 5-18% of women, which is associated with a significantly increased lifetime risk of concomitant diseases, including type 2 diabetes, psychiatric disorders, and gynecological cancers. Posttranslational modifications (PTMs) play an important role in changes in protein function and are necessary to maintain cellular viability and biological processes, thus their maladjustment can lead to disease. Growing evidence suggests the association between PCOS and posttranslational modifications. This article mainly reviews the research status of phosphorylation, methylation, acetylation, and ubiquitination, as well as their roles and molecular mechanisms in the development of PCOS. In addition, we briefly summarize research and clinical trials of PCOS therapy to advance our understanding of agents that can be used to target phosphorylated, methylated, acetylated, and ubiquitinated PTM types. It provides not only ideas for future research on the mechanism of PCOS but also ideas for PCOS treatments with therapeutic potential.

Dihydrotestosterone regulation of cyclooxygenase-2 expression in bovine endometrial epithelium cells by androgen receptor mediated EGFR/PI3K/Akt pathway

Uterine prostaglandins F2α (PGF2α) is essential for implantation, initiation of luteolysis and delivery. Previous studies have demonstrated that the expression of Cyclooxygenase-2 (COX-2), an enzyme limiting PGF2α rate, is regulated by steroid hormones, and also dihydrotestosterone (DHT) may be involved in regulating COX-2 expression both positively and negatively. However, it remains unclear how whether DHT regulates COX-2 expression and consequent PGF2α release in bovine endometrial epithelial cells (EECs). In this study, we evaluated the localization of the two isoforms of DHT synthetase 5α-reductase (5α-red1 and 5α-red2) and androgen receptor (AR) in bovine endometria by immunohistochemistry, and investigated 5α-red1, 5α-red2, AR, and DHT levels at the different stages of endometria (follicle, early-, mid-, and late-pregnancy phases). The results showed that 5α-red1, 5α-red2 and AR all were expressed in endometria, and their expressions and the level of DHT significantly increased in the late-pregnancy phase compared with the mid-pregnancy phase. Moreover, we cultured EECs from the mid-pregnancy phase and the in vitro study showed that DHT dose-dependently increased COX-2 expression and PGF2a release, but AR antagonist (flutamide) inhibited the stimulating effect via DHT. In addition, the DHT-induced COX-2 expression and PGF2α release were subjected to the regulation of both EGFR/PI3K/Akt/NFkB signaling as the inhibitors of EGFR (AG1478) and PI3K/Akt (LY294002) and NFkB (QNZ) attenuated the DHT mediated effect. Taken together, the results demonstrated that DHT-induced COX-2 expression and consequent PGF2α release in bovine EECs were mediated through AR-derived EGFR transactivation and PI3K/Akt cascade leading to NFkB activation.

Resveratrol and Markers of Polycystic Ovary Syndrome: a Systematic Review of Animal and Clinical Studies

Polycystic ovary syndrome (PCOS) is a common disorder affecting childbearing-age women, and is associated with reproductive and metabolic disturbances. The present study aimed to systematically review current animal studies and randomized placebo-controlled clinical trials (RCT) regarding the effects of resveratrol, a natural polyphenolic compound, on PCOS features. PubMed, Scopus, Web of Knowledge, and Google Scholar were comprehensively searched until December 2020. All original animal articles and RCTs evaluating the effects of resveratrol on PCOS were eligible for the review. Out of 289 initial records, eight animal studies and three RCTs met our inclusion criteria. Most of the included animal studies reported beneficial effects of resveratrol on the histomorphological features, sex hormones and gonadotropins, glycemic control, inflammation, and oxidative stress. Resveratrol also ameliorated ovarian volume, high-quality oocyte rate, high-quality embryo rate, androgens and gonadotropins concentrations, angiogenic factors levels, and endoplasmic reticulum stress in PCOS patients. Upregulation of sirtuin-1 was an examined mechanism proposed for some observed effects of resveratrol. The current literature is limited to conclude the beneficial effects of resveratrol on the management of PCOS. Although, according to the promising results of the animal studies and limited RCTs, resveratrol might be an effective phytochemical in PCOS control, especially regarding hormonal and reproductive abnormalities. More mechanistic studies and RCTs are warranted to obvious whether resveratrol can be prescribed in the clinical situation.

NRF2-Related Epigenetic Modifications in Cardiac and Vascular Complications of Diabetes Mellitus

Diabetes mellitus (DM) is a highly prevalent chronic disease that is accompanied with serious complications, especially cardiac and vascular complications. Thus, there is an urgent need to identify new strategies to treat diabetic cardiac and vascular complications. Nuclear factor erythroid 2-related factor 2 (NRF2) has been verified as a crucial target for the prevention and treatment of diabetic complications. The function of NRF2 in the treatment of diabetic complications has been widely reported, but the role of NRF2-related epigenetic modifications remains unclear. The purpose of this review is to summarize the recent advances in targeting NRF2-related epigenetic modifications in the treatment of cardiac and vascular complications associated with DM. We also discuss agonists that could potentially regulate NRF2-associated epigenetic mechanisms. This review provides a better understanding of strategies to target NRF2 to protect against DM-related cardiac and vascular complications.

Curcumin reverses diabetic nephropathy in streptozotocin-induced diabetes in rats by inhibition of PKCβ/p66Shc axis and activation of FOXO-3a

This study investigated if the nephroprotective effect of Curcumin in streptozotocin-induced type 1 diabetes mellitus (DM) in rats involves downregulation/inhibition of p66Shc and examined the underlying mechanisms. Rats were divided into 4 groups (n = 12/group) as control, control + Curcumin (100 mg/kg), T1DM, and T1DM + Curcumin. Curcumin was administered orally to control or diabetic rats for 12 weeks daily. As compared to diabetic rats, Curcumin didn't affect either plasma glucose or insulin levels but significantly reduced serum levels of urea, blood urea nitrogen, and creatinine, and concurrently reduced albumin/protein urea and increased creatinine clearance. It also prevented the damage in renal tubules and mitochondria, mesangial cell expansion, the thickness of the basement membrane. Mechanistically, Curcumin reduced mRNA and protein levels of collagen I/III and transforming growth factor- β-1 (TGF-β1), reduced inflammatory cytokines levels, improved markers of mitochondrial function, and suppressed the release of cytochrome-c and the activation of caspase-3. In the kidneys of both control and diabetic rats, Curcumin reduced the levels of reactive oxygen species (ROS), increased mRNA levels of manganese superoxide dismutase (MnSOD) and gamma-glutamyl ligase, increased glutathione (GSH) and protein levels of Bcl-2 and MnSOD, and increased the nuclear levels of nuclear factor2 (Nrf2) and FOXO-3a. Besides, Curcumin reduced the nuclear activity of the nuclear factor-kappa B (NF-κB), downregulated protein kinase CβII (PKCβII), NADPH oxidase, and p66Shc, and decreased the activation of p66Shc. In conclusion, Curcumin prevents kidney damage in diabetic rats by activating Nrf2, inhibiting Nf-κB, suppressing NADPH oxidase, and downregulating/inhibiting PKCβII/p66Shc axis.

Exposure to hyperandrogen drives ovarian dysfunction and fibrosis by activating the NLRP3 inflammasome in mice

Hyperandrogenism is the main cause of infertility as a result of polycystic ovary syndrome (PCOS). Long-term and continuous exposure to hyperandrogen can cause follicular developmental disorders. Ovarian granulosa cells (GCs) are critical in shaping the follicular development. To clarify how excessive androgen suppresses folliculogenesis and ovulation, we constructed PCOS mice by implantation of a 35-d testosterone (T) continuous-release pellet. Ovarian toll-like receptor 4 (TLR4) expression and serum IL-6 and IL-1β levels were dramatically increased in T-treated mice. In addition, the expression of NLRP3 inflammasome in the ovary of T-treated mice suggests that pyroptosis may play an essential role in follicular dysfunction. Lipopolysaccharide (LPS) has been extensively studied for activating cells by binding to TLR4. In this study, we demonstrated that LPS-induced inflammation leads to activation of the NLRP3 inflammasome with consequent impacts on follicular dysfunction. Herein we showed that LPS treatment upregulated the expression of 3β-hydroxysteroid dehydrogenase (3β-HSD) and androgen receptor (AR), while suppressed follicle stimulating hormone receptor (FSHR) expression in vitro. Moreover, we overexpressed NLRP3 using nigericin or lentiviral particles in GCs. The protein and mRNA levels of pyroptotic factors were highly enhanced with NLRP3 overexpression. As expected, the expression of Cyp19α1, Cyp11α1, 3β-HSD and FSHR at both the protein and mRNA levels was also markedly increased with excessive NLRP3. After inhibiting NLRP3, dihydrotestosterone (DHT)-treated GCs demonstrated markedly decreased NLRP3, the inflammasome adapter protein ASC, C-terminal fragment of gasdermin D (GSDMD-C), AR and Cyp19α1 at the protein level. Furthermore, with NLRP3 overexpression, the expression of fibrotic factors in ovarian cells was dramatically increased, such as TGF-β, CTGF, α-SMA, β-catenin, collagen I and collagen IV. These findings suggest that hyperandrogen stimulates chronic low-grade inflammation in the ovary to activate the NLRP3 inflammasome, further inducing a series of pathologies including ovarian GC pyroptotic death, follicular dysfunction and ovarian interstitial cell fibrosis.

Expression Regulation and Physiological Role of Transcription Factor FOXO3a During Ovarian Follicular Development

In mammals, developing ovarian follicles transform from primordial follicles to primary follicles, secondary follicles, and mature follicles, accompanied by changes in follicular secretory functions. FoxO3a is a member of the forkhead transcription factor family (FoxO), which plays an important role in the cell cycle, DNA damage repair, apoptosis, oxidative stress, and energy metabolism. Recent studies have shown that FOXO3a is involved in the physiological regulation of follicular development and pathological progression of related ovarian diseases, which will provide useful concepts and strategies for retarding ovarian aging, prolonging the ovarian life span, and treating ovarian diseases. Therefore, the regulation of FOXO3a expression, as well as the physiological contribution during ovarian follicular development are detailed in this paper, presenting an important reference for the further study of ovarian biology.