TLR4-Associated IRF-7 and NFκB Signaling Act as a Molecular Link Between Androgen and Metformin Activities and Cytokine Synthesis in the PCOS Endometrium

Systematic low-grade chronic inflammation and intrinsic mechanisms in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a prevalent endocrine and metabolic disorder affecting 6-20% of women of childbearing age worldwide. Immune cell imbalance and dysregulation of inflammatory factors can lead to systematic low-grade chronic inflammation (SLCI), which plays a pivotal role in the pathogenesis of PCOS. A significant higher infiltration of immune cells such as macrophages and lymphocytes and pro-inflammatory factors IL-6 and TNF-α has been detected in PCOS organ systems, impacting not only the female reproductive system but also other organs such as the cardiovascular, intestine, liver, thyroid, brain and other organs. Obesity, insulin resistance (IR), steroid hormones imbalance and intestinal microecological imbalance, deficiencies in vitamin D and selenium, as well as hyperhomocysteinemia (HHcy) can induce systematic imbalance between pro-inflammatory and anti-inflammatory cells and molecules. The pro-inflammatory cells and cytokines also interact with obesity, steroid hormones imbalance and IR, leading to increased metabolic imbalance and reproductive-endocrine dysfunction in PCOS patients. This review aims to summarize the dysregulation of immune response in PCOS organ system and the intrinsic mechanisms affecting SLCI in PCOS to provide new insights for the systemic inflammatory treatment of PCOS in the future.

A Systematic Review of the Molecular Mechanisms Involved in the Association Between PCOS and Endometrial and Ovarian Cancers

Polycystic ovary syndrome (PCOS), a major cause of female infertility, affects 4%-20% of reproductive-age women. Metabolic and hormonal alterations are key features of PCOS, potentially raising the risk of endometrial (EC) and ovarian (OVCA) cancers. This systematic review aims to summarise the proposed molecular mechanisms involved in the association between PCOS and EC or OVCA. This is achieved by conducting a thorough literature review and utilising specific search terms to identify all relevant studies published in English from 2010 to December 2022. PRISMA was followed, and the protocol was registered on PROSPERO (CRD42022375461). The QUADAS-2 tool and Review Manager Software were employed to evaluate study quality and risk of bias respectively. Forty-five eligible studies were selected with molecular signatures based on genomic, transcriptomic, metabolomic, proteomic and epigenetic analyses. Genes and their products deregulated in EC and/or OVCA were identified, including BRCA1, MLH1, NQO1 and ESR1, which were also deregulated in PCOS. Serum levels of IGF1, IGFBP1, SREBP1 and visfatin in women with PCOS were also identified as potential biomarkers of enhanced EC risk. Salusin-β serum levels in individuals with PCOS were identified as a potential biomarker for increased risk of OVCA. Gene signature-based drug repositioning identified several drug candidates: metformin, fenofibrate, fatostatin, melatonin, resveratrol and quercetin, some already established and prescribed for PCOS. In conclusion, this study provides a strong basis for further research to confirm the identified molecular signatures and associated causal links for potential therapeutic prevention strategies for EC and OVCA in women with PCOS.

Pharmacological and non-pharmacological interventions for improving endometrial receptivity in infertile patients with polycystic ovary syndrome: a comprehensive review of the available evidence

Direct and indirect evidence suggests that endometrial receptivity may play a crucial role in the reduced fertility rate of women with polycystic ovary syndrome (PCOS). Various pharmacological and non-pharmacological strategies with potential effects on endometrial receptivity in patients with PCOS have been proposed. The aim of this study was to summarize the rationale and the clinical and experimental evidence of interventions tested for improving endometrial receptivity in infertile patients with PCOS. A systematic review was conducted by consulting electronic databases. All interventions with a potential influence on endometrial receptivity in infertile patients with PCOS were evaluated, and their main biological mechanisms were analysed. In total, 24 interventions related to endometrial receptivity were identified. Notwithstanding a strong biological rationale, no intervention aimed at improving endometrial receptivity in women with PCOS is supported by an adequate body of evidence, limiting their use in clinical practice. Further high-quality research is needed in this field to limit potentially ineffective and unsafe add-on treatments in infertile patients with PCOS.

The identification of key genes and pathways in polycystic ovary syndrome by bioinformatics analysis of next-generation sequencing data

Background

Polycystic ovary syndrome (PCOS) is a reproductive endocrine disorder. The specific molecular mechanism of PCOS remains unclear. The aim of this study was to apply a bioinformatics approach to reveal related pathways or genes involved in the development of PCOS.

Methods

The next-generation sequencing (NGS) dataset GSE199225 was downloaded from the gene expression omnibus (GEO) database and NGS dataset analyzed is obtained from in vitro culture of PCOS patients’ muscle cells and muscle cells of healthy lean control women. Differentially expressed gene (DEG) analysis was performed using DESeq2. The g:Profiler was utilized to analyze the gene ontology (GO) and REACTOME pathways of the differentially expressed genes. A protein–protein interaction (PPI) network was constructed and module analysis was performed using HiPPIE and cytoscape. The miRNA-hub gene regulatory network and TF-hub gene regulatory network were constructed. The hub genes were validated by using receiver operating characteristic (ROC) curve analysis.

Results

We have identified 957 DEG in total, including 478 upregulated genes and 479 downregulated gene. GO terms and REACTOME pathways illustrated that DEG were significantly enriched in regulation of molecular function, developmental process, interferon signaling and platelet activation, signaling, and aggregation. The top 5 upregulated hub genes including HSPA5, PLK1, RIN3, DBN1, and CCDC85B and top 5 downregulated hub genes including DISC1, AR, MTUS2, LYN, and TCF4 might be associated with PCOS. The hub gens of HSPA5 and KMT2A, together with corresponding predicted miRNAs (e.g., hsa-mir-34b-5p and hsa-mir-378a-5p), and HSPA5 and TCF4 together with corresponding predicted TF (e.g., RCOR3 and TEAD4) were found to be significantly correlated with PCOS.

Conclusions

These study uses of bioinformatics analysis of NGS data to obtain hub genes and key signaling pathways related to PCOS and its associated complications. Also provides novel ideas for finding biomarkers and treatment methods for PCOS and its associated complications.

A spatiotemporal transcriptomic atlas of mouse placentation

The placenta, a temporary but essential organ for gestational support, undergoes intricate morphological and functional transformations throughout gestation. However, the spatiotemporal patterns of gene expression underlying placentation remain poorly understood. Utilizing Stereo-seq, we constructed a Mouse Placentation Spatiotemporal Transcriptomic Atlas (MPSTA) spanning from embryonic day (E) 7.5 to E14.5, which includes the transcriptomes of large trophoblast cells that were not captured in previous single-cell atlases. We defined four distinct strata of the ectoplacental cone, an early heterogeneous trophectoderm structure, and elucidated the spatial trajectory of trophoblast differentiation during early postimplantation stages before E9.5. Focusing on the labyrinth region, the interface of nutrient exchange in the mouse placenta, our spatiotemporal ligand-receptor interaction analysis unveiled pivotal modulators essential for trophoblast development and placental angiogenesis. We also found that paternally expressed genes are exclusively enriched in the placenta rather than in the decidual regions, including a cluster of genes enriched in endothelial cells that may function in placental angiogenesis. At the invasion front, we identified interface-specific transcription factor regulons, such as Atf3, Jun, Junb, Stat6, Mxd1, Maff, Fos, and Irf7, involved in gestational maintenance. Additionally, we revealed that maternal high-fat diet exposure preferentially affects this interface, exacerbating inflammatory responses and disrupting angiogenic homeostasis. Collectively, our findings furnish a comprehensive, spatially resolved atlas that offers valuable insights and benchmarks for future explorations into placental morphogenesis and pathology.

Role and mechanism of IRF9 in promoting the progression of rheumatoid arthritis by regulating macrophage polarization via PSMA5

Aim

To explore the mechanisms of IRF9 in the progression of rheumatoid arthritis(RA), and the effects of IRF9 on M1/M2 polarization.

Methods

RA dataset (GSE55457) was downloaded from GEO. Correlation analysis between IRF9 and its downstream target protein PSMA5 was performed using bioinformatics analysis. The M1/M2 cell ratio of peripheral blood mononuclear cells which from 20 healthy specimen and 40 RA patients was determined. The expression of IRF9 and PSMA5 was detected using qPCR and Western blot. Then, knockdown IRF9 in RAW264.7 cell line (sh-IRF9 RAW264.7) was constructed. The effect of sh-IRF9 RAW264.7 on RA was explored by constructing a CIA mouse model.

Results

IRF9 is upregulated in RA and is of good early screening effect. The results of pathway analysis showed that IRF9 targets and regulates the PSMA5 signaling pathway. IRF9 and PSMA5 were significantly elevated in RA patients, M1/M2 ratio was also increased. The effects of IRF9 on RAW264.7 macrophages were deeply explored in vitro, revealing that knockdown of IRF9 suppressed PSMA5, M1/M2 ratio and the secretion of pro-inflammatory factor in RAW264.7. In mouse in vivo experiments, sh-IRF9 RAW264.7 cells were found to modulate RA by downregulating PSMA5, modulating the M1/M2 ratio through enhancing the anti-inflammatory factor, and suppressing the pro-inflammatory factor.

Conclusion

IRF9 promoted the progression of RA via regulating macrophage polarization through PSMA5.

The IL-12 family of heterodimeric cytokines in polycystic ovarian syndrome: biological role in induction, regulation, and treatment

Polycystic ovary syndrome (PCOS) is a diverse endocrine disorder widely recognized as the prevailing metabolic condition among women in their reproductive years. The precise pathophysiological mechanisms underlying PCOS remain incompletely understood. However, existing evidence suggests that the development of PCOS may be linked to factors such as abdominal obesity, hyperandrogenism, and insulin resistance (IR). Excessive central adiposity in women with PCOS may lead to the development of a chronic, low-grade inflammation characterized by the activation of proinflammatory cytokines. The cytokines that belong to the IL-12 family are a collection of distinct heterodimeric cytokines that include IL-12, IL-23, IL-27, and IL-35. Recent research has provided further evidence regarding the significance of IL-12 cytokines in influencing both innate and adaptive immune responses in different diseases. Additionally, these studies have discovered diverse roles for certain members of the IL-12 family, encompassing multiple immunological functions that can either act as effectors or regulators. In this discourse, we examine the distinctive and atypical structural and functional attributes of this particular cytokine family. This study aims to offer a comprehensive overview of the pathophysiological significance of the IL-12 family cytokines in PCOS patients. Additionally, the therapeutic potential of the cytokines as novel approaches for PCOS treatment will be proposed.

Berberine alleviates inflammation in polycystic ovary syndrome by inhibiting hyaluronan synthase 2 expression

BACKGROUND

Polycystic ovary syndrome (PCOS) is a heterogeneous metabolic and endocrine disorder that causes anovulatory infertility and abnormal folliculogenesis in women of reproductive age. Several studies have revealed inflammation in PCOS follicles, and recent evidence suggests that Berberine (BBR) effectively reduces inflammatory responses in PCOS, however, the underlying mechanisms remain unclear.

PURPOSE

To determine the underlying mechanisms by which BBR alleviates inflammation in PCOS.

STUDY DESIGN

Primary human GCs from healthy women and women with PCOS, and KGN cells were used for in vitro studies. ICR mice were used for in vivo studies.

METHODS

Gene expression was measured using RT-qPCR. HAS2, inflammatory cytokines, and serum hormones were assayed by ELISA. Protein expression profiles were assayed by Western blot. Chronic low-grade inflammatory mouse models were developed by intraperitoneal injection with LPS, and PCOS mouse models were established by subcutaneous intraperitoneal injection of DHEA. BBR and 4-MU were administered by gavage. Ovarian morphologic changes were evaluated using H&E staining. HAS2 expression in the ovary was assayed using Western blot and immunohistochemistry.

RESULTS

Our results confirmed that HAS2 expression and hyaluronan (HA) accumulation are closely associated with inflammatory responses in PCOS. Data obtained from in vitro studies showed that HAS2 and inflammatory genes (e.g., MCP-1, IL-1β, and IL-6) are significantly upregulated in PCOS samples and LPS-induced KGN cells compared to their control groups. In addition, these effects were reversed by blocking HAS2 expression or HA synthesis using BBR or 4-MU, respectively. Furthermore, HAS2 overexpression induces the expression of inflammatory genes in PCOS. These results were further confirmed in LPS- and DHEA-induced mouse models, where inflammatory genes were reduced by BBR or 4-MU, and ovarian morphology was restored.

CONCLUSIONS

Our results define previously unknown links between HAS2 and chronic low-grade inflammation in the follicles of women with PCOS. BBR exerts its anti-inflammatory effects by down-regulating HAS2. This study provides a novel therapeutic target for alleviating ovarian inflammation in women with PCOS.

Dissecting the shared genetic architecture between endometriosis and polycystic ovary syndrome

Background

Previous study suggested evidence for coexistence and similarities between endometriosis and polycystic ovary syndrome (PCOS), but it is unclear regarding the shared genetic architecture and causality underlying the phenotypic similarities observed for endometriosis and PCOS.

Methods

By leveraging summary statistics from public genome-wide association studies regarding endometriosis (European-based: N=470,866) and PCOS (European-based: N=210,870), we explored the genetic correlation that shared between endometriosis and PCOS using linkage disequilibrium score regression. Shared risk SNPs were derived using PLACO (Pleiotropic analysis under composite null hypothesis) and FUMA (Functional Mapping and Annotation of Genetic Associations). The potential causal association between endometriosis and PCOS was investigated using two-sample Mendelian randomization (MR). Linkage disequilibrium score for the specific expression of genes analysis (LDSC-SEG) were performed for tissue enrichment analysis. The expression profiles of the risk gene in tissues were further examined.

Results

A positive genetic association was observed between endometriosis and PCOS. 12 significant pleiotropic loci shared between endometriosis and PCOS were identified. Genetic associations between endometriosis and PCOS were particularly enriched in uterus, endometrium and fallopian tube. Two-sample MR analysis further indicated a potential causative effect of endometriosis on PCOS, and vice versa. Microarray and RNA-seq verified the expressions of SYNE1 and DNM3 were significantly altered in the endometrium of patients with endometriosis or PCOS compared to those of control subjects.

Conclusion

Our study indicates the genetic correlation and shared risk genes between PCOS and endometriosis. These findings provide insights into the potential mechanisms behind their comorbidity and the future development of therapeutics.

Immune dysfunction mediated by the competitive endogenous RNA network in fetal side placental tissue of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), a common endocrine and metabolic disorder affecting women in their reproductive years. Emerging evidence suggests that the maternal-fetal immune system is crucial for proper pregnancy. However, whether immune function is altered at the end of pregnancy in PCOS women and the underlying molecular mechanisms is currently unexplored. Herein, the basic maternal immune system was investigated (n = 136 in the control group; n = 103 in the PCOS group), and whole-transcriptome sequencing was carried out to quantify the mRNAs, miRNAs, and lncRNAs expression levels in fetal side placental tissue of women with PCOS. GO, KEGG, and GSEA analysis were employed for functional enrichment analysis. The process of identifying hub genes was conducted utilizing the protein-protein interaction network. CIBERSORT and Connectivity Map were deployed to determine immune cell infiltration and predict potential drugs, respectively. A network of mRNA-miRNA-lncRNA was constructed and then validated by qRT-PCR. First, red blood cell count, neutrophil count, lymphocyte count, hypersensitive C-reactive protein, and procalcitonin were significantly elevated, while placental growth factor was hindered in PCOS women. We identified 308 DEmRNAs, 77 DEmiRNAs, and 332 DElncRNAs in PCOS samples. Functional enrichment analysis revealed that there were significant changes observed in terms of the immune system, especially the chemokine pathway. Eight genes, including FOS, JUN, EGR1, CXCL10, CXCR1, CXCR2, CXCL11, and CXCL8, were considered as hub genes. Furthermore, the degree of infiltration of neutrophils was dramatically decreased in PCOS tissues. In total, 57 ceRNA events were finally obtained, and immune-related ceRNA networks were validated. Some potential drug candidates, such as enalapril and RS-100329, could have a function in PCOS therapy. This study represents the inaugural attempt to evaluate the immune system at the end of pregnancy and placental ceRNA networks in PCOS, indicating alterations in the chemokine pathway, which may impact fetal and placental growth, and provides new therapy targets.

Insulin-sensitizing agents for infertility treatment in woman with polycystic ovary syndrome: a narrative review of current clinical practice

PURPOSE

Polycystic ovary syndrome (PCOS) is an endocrine, metabolic, and reproductive disorder which, according to the Rotterdam criteria, affects up to 24% of women of childbearing age. Although the prevalence of infertility in this subpopulation of women is high, the optimal treatment has not been fully established yet. Insulin resistance is considered to be an important mechanism involved in the development of PCOS; hence, the aim of this narrative review is to present an overview of the current pharmacological insulin-sensitizing treatment modalities for infertile women with PCOS.

METHODS

A MEDLINE and PubMed search for the years 1990-2023 was performed using a combination of keywords. Clinical trials with insulin sensitizers used for infertility treatment as well as analyses of systematic reviews and meta-analyses were evaluated. When deemed necessary, additional articles referenced in the retrieved papers were included in this narrative review.

RESULTS

Several insulin-sensitizing compounds and various therapeutical protocols are available for infertility treatment of women with PCOS. Metformin is the most common adjuvant medication to induce ovulation in infertile women with PCOS and is more frequently administered in combination with clomiphene citrate than on its own. Recently, inositol and glucagon-like peptide-1 (GLP-1) receptor agonists have emerged as possible options for infertility treatment in PCOS.

CONCLUSION

The future of medical treatment of PCOS women with infertility lies in a personalized pharmacological approach, which involves various compounds with different mechanisms of action that could modify ovarian function and endometrial receptivity, ultimately leading to better overall reproductive outcomes in these women.

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.

Androgen excess: a hallmark of polycystic ovary syndrome

Polycystic ovarian syndrome (PCOS) is a metabolic, reproductive, and psychological disorder affecting 6-20% of reproductive women worldwide. However, there is still no cure for PCOS, and current treatments primarily alleviate its symptoms due to a poor understanding of its etiology. Compelling evidence suggests that hyperandrogenism is not just a primary feature of PCOS. Instead, it may be a causative factor for this condition. Thus, figuring out the mechanisms of androgen synthesis, conversion, and metabolism is relatively important. Traditionally, studies of androgen excess have largely focused on classical androgen, but in recent years, adrenal-derived 11-oxygenated androgen has also garnered interest. Herein, this Review aims to investigate the origins of androgen excess, androgen synthesis, how androgen receptor (AR) signaling mediates adverse PCOS traits, and the role of 11-oxygenated androgen in the pathophysiology of PCOS. In addition, it provides therapeutic strategies targeting hyperandrogenism in PCOS.

Metformin: A Potential Treatment for Acne, Hidradenitis Suppurativa and Rosacea

Metformin is a widely used drug for treatment of diabetes mellitus, due to its safety and efficacy. In addition to its role as an antidiabetic drug, numerous beneficial effects of metformin have enabled its use in various diseases. Considering the anti-androgenic, anti-angiogenic, anti-fibrotic and antioxidant properties of metformin, it may have the potential to improve chronic inflammatory skin diseases. However, further evidence is needed to confirm the efficacy of metformin in dermatological conditions, This review focuses on exploring the therapeutic targets of metformin in acne vulgaris, hidradenitis suppurativa and rosacea, by studying their pathogeneses.

Proteomic and bioinformatic analysis of human endometrium from polycystic ovarian syndrome with and without insulin resistance

Objective: The aim of this study was to investigate the endometrial proteomic profiles of patients with polycystic ovary syndrome (PCOS) with and without insulin resistance (IR). Method of Study: We collected 40 endometrial samples, including PCOS-IR (n = 21), PCOS-non-IR (n = 12), and control (n = 7). Data-independent acquisition (DIA)-based proteomics method is used to identify the expressed proteins among the three groups. The correlation between pregnancy outcomes and identified proteins was analyzed by Lasso regression. Results: A total of 5331 proteins were identified, while 275 proteins were differentially expressed in the PCOS vs. control group and 215 proteins were differentially expressed in the PCOS-IR vs. PCOS-non-IR group. Platelet degranulation, neutrophil degranulation, and very long-chain fatty acid catabolic processes have been found to play important roles in the endometrium of patients with PCOS-IR. Lasso regression analysis found that ACTR1A, TSC22D2, CKB, ABRAXAS2, and TAGLN2 were associated with miscarriage in patients with PCOS. ACTR1A and CKB were higher in the PCOS-IR group and were positively correlated with HOMA-IR (p < .05). Conclusion: In this study, a panel of proteins was found to be differently expressed in the endometrium. ACTR1A and CKB may be considered as PCOS-IR candidate biomarkers.

Chronic endometritis incidence in infertile women with and without polycystic ovary syndrome: a propensity score matched study

BACKGROUND

Polycystic ovary syndrome (PCOS) is known to be associated with chronic low-grade inflammation and endometrial dysfunction. Chronic endometritis (CE) is a type of local inflammation that can contribute to endometrial dysfunction in infertile women. Some clinicians recommend screening for CE in women at high risk, such as those with endometrial polyps. However, it is still uncertain whether there is a relationship between PCOS and CE, as well as whether women with PCOS require enhanced screening for CE. This study was to assess the incidence of CE among infertile women with PCOS by hysteroscopy combined with histopathology CD138 immunohistochemical staining of endometrium.

METHODS

A total of 205 patients in the PCOS group and 4021 patients in the non-PCOS group from July 2017 to August 2022 were included in this retrospective study. After nearest-neighbor 1:4 propensity score matching (PSM), 189 PCOS patients were matched with 697 non-PCOS patients. Basic information was recorded. The CE incidence was compared. The risk factors affecting CE incidence were also analyzed.

RESULTS

No significantly higher CE incidence in infertile women with PCOS were found either in total analysis or after PSM (P = 0.969; P = 0.697; respectively). Similar results were discovered in the subgroup of Body Mass Index (BMI) (P = 0.301; P = 0.671; P = 0.427; respectively) as well as the four PCOS phenotypes (P = 0.157). Intriguingly, the incidence of CE increased as BMI increased in the PCOS group, even though no significant differences were found (P = 0.263). Multivariate logistic regression showed that age, infertility duration, infertility type, PCOS, and obesity were not the independent risk factors affecting CE incidence.

CONCLUSION

The incidence of CE in PCOS patients did not significantly increase compared to non-PCOS patients. Similarly, no significant differences in the incidence of CE were observed among different PCOS phenotypes. The current evidence does not substantiate the need for widespread CE screening among PCOS women, potentially mitigating the undue financial and emotional strain associated with such screenings.

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.

Immunomodulatory Effects of Metformin Treatment in Pregnant Women With PCOS

CONTEXT

Polycystic ovary syndrome (PCOS) is a common endocrine disorder associated with low-grade systemic inflammation and increased risk of pregnancy complications. Metformin treatment reduces the risk of late miscarriage and preterm birth in pregnant women with PCOS. Whether the protective effect of metformin involves immunological changes has not been determined.

OBJECTIVE

To investigate the effect of metformin on the maternal immunological status in women with PCOS.

METHODS

A post-hoc analysis was performed of two randomized controlled trials, PregMet and PregMet2, including longitudinal maternal serum samples from 615 women with PCOS. Women were randomized to metformin or placebo from first trimester to delivery. Twenty-two cytokines and C-reactive protein were measured in serum sampled at gestational weeks 5 to 12, 19, 32, and 36.

RESULTS

Metformin treatment was associated with higher serum levels of several multifunctional cytokines throughout pregnancy, with the strongest effect on eotaxin (P < .001), interleukin-17 (P = .03), and basic fibroblast growth factor (P = .04). Assessment of the combined cytokine development confirmed the impact of metformin on half of the 22 cytokines. The immunomodulating effect of metformin was more potent in normal weight and overweight women than in obese women. Moreover, normoandrogenic women had the strongest effect of metformin in early pregnancy, whereas hyperandrogenic women presented increasing effect throughout pregnancy.

CONCLUSION

It appears that metformin has immunomodulating rather than anti-inflammatory properties in pregnancy. Its effect on the serum levels of many multifunctional cytokines demonstrates robust, persisting, and body mass-dependent immune mobilization in pregnant women with PCOS.

When the allergy alarm bells toll: The role of Toll-like receptors in allergic diseases and treatment

Toll-like receptors of the human immune system are specialized pathogen detectors able to link innate and adaptive immune responses. TLR ligands include among others bacteria-, mycoplasma- or virus-derived compounds such as lipids, lipo- and glycoproteins and nucleic acids. Not only are genetic variations in TLR-related genes associated with the pathogenesis of allergic diseases, including asthma and allergic rhinitis, their expression also differs between allergic and non-allergic individuals. Due to a complex interplay of genes, environmental factors, and allergen sources the interpretation of TLRs involved in immunoglobulin E-mediated diseases remains challenging. Therefore, it is imperative to dissect the role of TLRs in allergies. In this review, we discuss i) the expression of TLRs in organs and cell types involved in the allergic immune response, ii) their involvement in modulating allergy-associated or -protective immune responses, and iii) how differential activation of TLRs by environmental factors, such as microbial, viral or air pollutant exposure, results in allergy development. However, we focus on iv) allergen sources interacting with TLRs, and v) how targeting TLRs could be employed in novel therapeutic strategies. Understanding the contributions of TLRs to allergy development allow the identification of knowledge gaps, provide guidance for ongoing research efforts, and built the foundation for future exploitation of TLRs in vaccine design.

Dysregulation of immune response in PCOS organ system

Polycystic ovary syndrome (PCOS) is the most common reproductive endocrine disorder affecting women, which can lead to infertility. Infertility, obesity, hirsutism, acne, and irregular menstruation are just a few of the issues that PCOS can be linked to. PCOS has a complicated pathophysiology and a range of clinical symptoms. Chronic low-grade inflammation is one of the features of PCOS. The inflammatory environment involves immune and metabolic disturbances. Numerous organ systems across the body, in addition to the female reproductive system, have been affected by the pathogenic role of immunological dysregulation in PCOS in recent years. Insulin resistance and hyperandrogenism are associated with immune cell dysfunction and cytokine imbalance. More importantly, obesity is also involved in immune dysfunction in PCOS, leading to an inflammatory environment in women with PCOS. Hormone, obesity, and metabolic interactions contribute to the pathogenesis of PCOS. Hormone imbalance may also contribute to the development of autoimmune diseases. The aim of this review is to summarize the pathophysiological role of immune dysregulation in various organ systems of PCOS patients and provide new ideas for systemic treatment of PCOS in the future.

Regulatory mechanisms of HMGB1 and its receptors in polycystic ovary syndrome-driven gravid uterine inflammation

High-mobility group box 1 (HMGB1) is critical for inflammatory homeostasis and successful pregnancy, and there is a strong association among elevated levels of HMGB1, polycystic ovary syndrome (PCOS), chronic inflammation and pregnancy loss. However, the mechanisms responsible for PCOS-driven regulation of uterine HMGB1 and its candidate receptors [toll-like receptor (TLR) 2 and 4] and inflammatory responses during pregnancy remain unclear. In this study, we found a gestational stage-dependent decrease in uterine HMGB1 and TLR4 protein abundance in rats during normal pregnancy. We demonstrated that increased expression of HMGB1, TLR2 and TLR4 proteins was associated with activation of inflammation-related signalling pathways in the gravid uterus exposed to 5α-dihydrotestosterone and insulin, mimicking the clinical features (hyperandrogenism and insulin resistance) of PCOS and this elevation was completely inhibited by treatment with the androgen receptor (AR) antagonist flutamide. Interestingly, acute exposure to lipopolysaccharide suppressed HMGB1, TLR4 and inflammation-related protein abundance but did not affect androgen levels or AR expression in the gravid uterus with viable fetuses. Furthermore, immunohistochemical analysis revealed that, in addition to being localized predominately in the nuclear compartment, HMGB1 immunoreactivity was also detected in the cytoplasm in the PCOS-like rat uterus, PCOS endometrium and pregnant rat uterus with haemorrhagic and resorbed fetuses, possibly via activation of nuclear factor κB signalling. These results suggest that both AR-dependent and AR-independent mechanisms contribute to the modulation of HMGB1/TLR2/TLR4-mediated uterine inflammation. We propose that the elevation of HMGB1 and its receptors and disruption of the pro-/anti-inflammatory balance in the gravid uterus may participate in the pathophysiology of PCOS-associated pregnancy loss.

Transcriptomic screening to identify hub genes and drug signatures for PCOS based on RNA-Seq data in granulosa cells

BACKGROUND

Polycystic ovary syndrome (PCOS) is one of the most incident reproductive diseases, and remains the main cause of female infertility. Granulosa cells play a critical role in normal follicle development and steroid hormones synthesis. In spite of extensive research, no sole medication has been approved by FDA to treat PCOS. This study aimed to investigate the novel therapeutics targets in PCOS, focusing on granulosa cells transcriptome functional analysis with a drug repositioning approach.

METHODS

PCOS microarray and RNA-Seq datasets in granulosa cells were screened and reanalyzed. KEGG pathway enrichment and interaction network analyses were performed and followed by a set of drug signature screening and Poly-pharmacology survey.

RESULTS

545 deregulated genes were identified via filters including p_adj < 0.05 and |log2FC| > 1. Amongst the top 15 KEGG pathways significantly enriched, metabolism of xenobiotics by cytochrome P450, steroid hormone biosynthesis and ovarian steroidogenesis were observed. The Protein-Protein Interaction network identified 18 hub genes amongst this set. Interestingly, most candidate drug signatures have been introduced by databases are either FDA approved or entered into clinical trials, including melatonin, resveratrol and raloxifene. Investigational or experimental introduced drugs obey rules of drug-likeness with almost safe and acceptable ADMET properties. Notably, 21 top target genes of the final drug set were also included in the granulosa significant differentially expressed genes.

CONCLUSION

Results of the current study represent approved, investigational and experimental drug signatures according to the differentially expressed genes in granulosa cells with supported literature reviews. This data might be useful for researchers and clinicians to pave the way for better management of PCOS.

Insight into TLR4 receptor inhibitory activity via QSAR for the treatment of Mycoplasma pneumonia disease

Mycoplasma pneumoniae (MP) is one of the most common pathogenic organisms causing upper and lower respiratory tract infections, lung injury, and even death in young children. Toll-like receptors (TLRs) play an important role in innate immunity by allowing the host to recognize pathogens invading the body. Previous studies demonstrated that TLR4 is a potential therapeutic target for the treatment of MP pneumonia. Therefore, the present study aimed to screen biologically active ingredients that target the TLR4 receptor pathway. We first used molecular docking to screen out the active compounds inhibiting the TLR4 pathway, and then used regression and classification machine learning algorithms to establish a quantitative structure-activity relationship (QSAR) model to predict the biological activity of the screened compounds. A total of 78 molecules were used in QSAR modelling, which were retrieved from the ChEMBL database. The QSAR models had acceptable correlation coefficients of R ² on the training and testing dataset in the range of 0.96 to 0.91 and 0.93 to 0.76, respectively. The multiclass classification models showed accuracy on training and testing data within ranges of 1.0 to 0.70, 0.96 to 0.63, and log loss ranges from 0.27 to 8.63, respectively. In addition, molecular descriptors and fingerprints have been studied as structural elements involved in increased and decreased inhibitory activities. These results provide a quantitative analysis of QSAR and classification models applicable for high-throughput screening, as well as insights into the mechanisms of inhibition of TLR4 antagonists.

Exploration of hub genes involved in PCOS using biological informatics methods

BACKGROUND

The aim of this study was to find underlying genes and their interaction mechanism crucial to the polycystic ovarian syndrome (PCOS) by analyzing differentially expressed genes (DEGs) between PCOS and non-PCOS subjects.

METHODS

Gene expression data of PCOS and non-PCOS subjects were collected from gene expression omnibus (GEO) database. GEO2R were used to calculating P value and logFC. The screening threshold of DEGs was P < .05 and | FC | ≥ 1.2. GO annotation and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway enrichment analysis was performed by using DAVID (2021 Update). The protein-protein interaction (PPI) network of DEGs was constructed by using the STRING database, and the hub genes were recognized through Hubba plugin of Cytoscape software.

RESULTS

PCOS and non-PCOS subjects shared a total of 174 DGEs, including 14 upregulated and 160 downregulated genes. The GO biological processes enriched by DEGs mainly involved actin cytoskeleton organization, positive regulation of NF-κB signaling pathway, and positive regulation of canonical Wnt signaling pathway. The DEGs were significantly enriched in cytoplasm, nucleus and cytosol. Their molecular functions mainly focused on protein binding, calmodulin binding and glycerol-3-phosphate dehydrogenase activity. The PI3K/Akt signaling pathway and glycosaminoglycan biosynthesis were highlighted as critical pathways enriched by DEGs. 10 hub genes were screened from the constructed PPI network, of which EGF, FN1 and TLR4 were mainly enriched in the PI3K/Akt signaling pathway.

CONCLUSION

In this study, a total of 174 DEGs and 10 hub genes were identified as new candidate targets for insulin resistance (IR) in PCOS individuals, which may provide a new direction for developing novel treatment strategies for PCOS.

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.

Metformin for Cardiovascular Protection, Inflammatory Bowel Disease, Osteoporosis, Periodontitis, Polycystic Ovarian Syndrome, Neurodegeneration, Cancer, Inflammation and Senescence: What Is Next?

Diabetes is accompanied by several complications. Higher prevalence of cancers, cardiovascular diseases, chronic kidney disease (CKD), obesity, osteoporosis, and neurodegenerative diseases has been reported among patients with diabetes. Metformin is the oldest oral antidiabetic drug and can improve coexisting complications of diabetes. Clinical trials and observational studies uncovered that metformin can remarkably prevent or alleviate cardiovascular diseases, obesity, polycystic ovarian syndrome (PCOS), osteoporosis, cancer, periodontitis, neuronal damage and neurodegenerative diseases, inflammation, inflammatory bowel disease (IBD), tuberculosis, and COVID-19. In addition, metformin has been proposed as an antiaging agent. Numerous mechanisms were shown to be involved in the protective effects of metformin. Metformin activates the LKB1/AMPK pathway to interact with several intracellular signaling pathways and molecular mechanisms. The drug modifies the biologic function of NF-κB, PI3K/AKT/mTOR, SIRT1/PGC-1α, NLRP3, ERK, P38 MAPK, Wnt/β-catenin, Nrf2, JNK, and other major molecules in the intracellular signaling network. It also regulates the expression of noncoding RNAs. Thereby, metformin can regulate metabolism, growth, proliferation, inflammation, tumorigenesis, and senescence. Additionally, metformin modulates immune response, autophagy, mitophagy, endoplasmic reticulum (ER) stress, and apoptosis and exerts epigenetic effects. Furthermore, metformin protects against oxidative stress and genomic instability, preserves telomere length, and prevents stem cell exhaustion. In this review, the protective effects of metformin on each disease will be discussed using the results of recent meta-analyses, clinical trials, and observational studies. Thereafter, it will be meticulously explained how metformin reprograms intracellular signaling pathways and alters molecular and cellular interactions to modify the clinical presentations of several diseases.

Suppression of uterine and placental ferroptosis by N-acetylcysteine in a rat model of polycystic ovary syndrome

The mechanisms that link hyperandrogenism and insulin (INS) resistance (HAIR) to the increased miscarriage rate in women with polycystic ovary syndrome (PCOS) remain elusive. Previous studies demonstrate that increased uterine and placental ferroptosis is associated with oxidative stress-induced fetal loss in a pre-clinical PCOS-like rat model. Here, we investigated the efficacy and molecular mechanism of action of the antioxidant N-acetylcysteine (NAC) in reversing gravid uterine and placental ferroptosis in pregnant rats exposed to 5α-dihydrotestosterone (DHT) and INS. Molecular and histological analyses showed that NAC attenuated DHT and INS-induced uterine ferroptosis, including dose-dependent increases in anti-ferroptosis gene content. Changes in other molecular factors after NAC treatment were also observed in the placenta exposed to DHT and INS, such as increased glutathione peroxidase 4 protein level. Furthermore, increased apoptosis-inducing factor mitochondria-associated 2 mRNA expression was seen in the placenta but not in the uterus. Additionally, NAC was not sufficient to rescue DHT + INS-induced mitochondria-morphological abnormalities in the uterus, whereas the same treatment partially reversed such abnormalities in the placenta. Finally, we demonstrated that NAC selectively normalized uterine leukemia inhibitory factor, osteopontin/secreted phosphoprotein 1, progesterone receptor, homeobox A11 mRNA expression and placental estrogen-related receptor beta and trophoblast-specific protein alpha mRNA expression. Collectively, our data provide insight into how NAC exerts beneficial effects on differentially attenuating gravid uterine and placental ferroptosis in a PCOS-like rat model with fetal loss. These results indicate that exogenous administration of NAC represents a potential therapeutic strategy in the treatment of HAIR-induced uterine and placental dysfunction.

Metformin Corrects Glucose Metabolism Reprogramming and NLRP3 Inflammasome-Induced Pyroptosis via Inhibiting the TLR4/NF-κB/PFKFB3 Signaling in Trophoblasts: Implication for a Potential Therapy of Preeclampsia

NOD-like receptor family, pyrin domain-containing protein 3 (NLRP3) inflammasome-mediated pyroptosis is a crucial event in the preeclamptic pathogenesis, tightly linked with the uteroplacental TLR4/NF-κB signaling. Trophoblastic glycometabolism reprogramming has now been noticed in the preeclampsia pathogenesis, plausibly modulated by the TLR4/NF-κB signaling as well. Intriguingly, cellular pyroptosis and metabolic phenotypes may be inextricably linked and interacted. Metformin (MET), a widely accepted NF-κB signaling inhibitor, may have therapeutic potential in preeclampsia while the underlying mechanisms remain unclear. Herein, we investigated the role of MET on trophoblastic pyroptosis and its relevant metabolism reprogramming. The safety of pharmacologic MET concentration to trophoblasts was verified at first, which had no adverse effects on trophoblastic viability. Pharmacological MET concentration suppressed NLRP3 inflammasome-induced pyroptosis partly through inhibiting the TLR4/NF-κB signaling in preeclamptic trophoblast models induced via low-dose lipopolysaccharide. Besides, MET corrected the glycometabolic reprogramming and oxidative stress partly via suppressing the TLR4/NF-κB signaling and blocking transcription factor NF-κB1 binding on the promoter PFKFB3, a potent glycolytic accelerator. Furthermore, PFKFB3 can also enhance the NF-κB signaling, reduce NLRP3 ubiquitination, and aggravate pyroptosis. However, MET suppressed pyroptosis partly via inhibiting PFKFB3 as well. These results provided that the TLR4/NF-κB/PFKFB3 pathway may be a novel link between metabolism reprogramming and NLRP3 inflammasome-induced pyroptosis in trophoblasts. Further, MET alleviates the NLRP3 inflammasome-induced pyroptosis, which partly relies on the regulation of TLR4/NF-κB/PFKFB3-dependent glycometabolism reprogramming and redox disorders. Hence, our results provide novel insights into the pathogenesis of preeclampsia and propose MET as a potential therapy.

The abnormal level of HSP70 is related to Treg/Th17 imbalance in PCOS patients

BACKGROUND

Polycystic ovary syndrome (PCOS) is a disease with chronic nonspecific low-grade inflammation. The imbalance of immune cells exists in PCOS. Several studies have found that heat shock protein 70 (HSP70) may be involved in the immunological pathogenesis of PCOS, but the relationship between HSP70 and Regulatory T cell (Treg)/T helper cell 17(Th17) ratio remains unclear. This study aims to explore the correlation between HSP70 and Treg/Th17 ratio and to provide evidence for the role of HSP70 in the immunological etiology of PCOS.

RESULTS

There was no significant difference in age and body mass index (BMI) between the two groups. The concentrations of basal estradiol (E₂), basal follicle-stimulating hormone (FSH) did not show a significant difference between the two groups. The concentrations of basal luteinizing hormone (LH) (P < 0.01), testosterone (T) (P < 0.01), glucose (P < 0.001) and insulin (P < 0.001) in PCOS patients were significantly higher than those in the control group. The protein levels of HSP70 were significantly higher in serum in the PCOS group (P < 0.001). The percentage of Treg cells was significantly lower (P < 0.01), while the percentage of the Th17 cells of the PCOS group was significantly higher than that of the control group (P < 0.05). The ratio of Treg/Th17 in the PCOS group was significantly lower (P < 0.001). The concentrations of Interleukin (IL)-6, IL-17, and IL-23 were significantly higher, while the levels of IL-10 and Transforming growth factor-β (TGF-β) were significantly lower in the PCOS group (P < 0.001). Spearman rank correlation analysis showed a strong negative correlation of serum HSP70 levels with Treg/Th17 ratio, IL-10, and TGF-β levels. In contrast, HSP70 levels were significantly positively correlated with IL-6, IL-17, IL-23, LH, insulin, and glucose levels.

CONCLUSION

The abnormal level of HSP70 is correlated with Treg/Th17 imbalance and corresponding cytokines, which indicates that HSP70 may play an important role in PCOS immunologic pathogenesis.

Increased uterine androgen receptor protein abundance results in implantation and mitochondrial defects in pregnant rats with hyperandrogenism and insulin resistance

Abstract

In this study, we show that during normal rat pregnancy, there is a gestational stage-dependent decrease in androgen receptor (AR) abundance in the gravid uterus and that this is correlated with the differential expression of endometrial receptivity and decidualization genes during early and mid-gestation. In contrast, exposure to 5α-dihydrotestosterone (DHT) and insulin (INS) or DHT alone significantly increased AR protein levels in the uterus in association with the aberrant expression of endometrial receptivity and decidualization genes, as well as disrupted implantation. Next, we assessed the functional relevance of the androgen-AR axis in the uterus for reproductive outcomes by treating normal pregnant rats and pregnant rats exposed to DHT and INS with the anti-androgen flutamide. We found that AR blockage using flutamide largely attenuated the DHT and INS-induced maternal endocrine, metabolic, and fertility impairments in pregnant rats in association with suppressed induction of uterine AR protein abundance and androgen-regulated response protein and normalized expression of several endometrial receptivity and decidualization genes. Further, blockade of AR normalized the expression of the mitochondrial biogenesis marker Nrf1 and the mitochondrial functional proteins Complexes I and II, VDAC, and PHB1. However, flutamide treatment did not rescue the compromised mitochondrial structure resulting from co-exposure to DHT and INS. These results demonstrate that functional AR protein is an important factor for gravid uterine function. Impairments in the uterine androgen-AR axis are accompanied by decreased endometrial receptivity, decidualization, and mitochondrial dysfunction, which might contribute to abnormal implantation in pregnant PCOS patients with compromised pregnancy outcomes and subfertility.

Key messages

The proper regulation of uterine androgen receptor (AR) contributes to a normal pregnancy process, whereas the aberrant regulation of uterine AR might be linked to polycystic ovary syndrome (PCOS)-induced pregnancy-related complications.

In the current study, we found that during normal rat pregnancy there is a stage-dependent decrease in AR abundance in the gravid uterus and that this is correlated with the differential expression of the endometrial receptivity and decidualization genes Spp1, Prl, Igfbp1, and Hbegf.

Pregnant rats exposed to 5α-dihydrotestosterone (DHT) and insulin (INS) or to DHT alone show elevated uterine AR protein abundance and implantation failure related to the aberrant expression of genes involved in endometrial receptivity and decidualization in early to mid-gestation.

Treatment with the anti-androgen flutamide, starting from pre-implantation, effectively prevents DHT + INS-induced defects in endometrial receptivity and decidualization gene expression, restores uterine mitochondrial homeostasis, and increases the pregnancy rate and the numbers of viable fetuses.

This study adds to our understanding of the mechanisms underlying poor pregnancy outcomes in PCOS patients and the possible therapeutic use of anti-androgens, including flutamide, after spontaneous conception.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00109-021-02104-z.

Adrenal insufficiency

Adrenal insufficiency (AI) is a condition characterized by an absolute or relative deficiency of adrenal cortisol production. Primary AI (PAI) is rare and is caused by direct adrenal failure. Secondary AI (SAI) is more frequent and is caused by diseases affecting the pituitary, whereas in tertiary AI (TAI), the hypothalamus is affected. The most prevalent form is TAI owing to exogenous glucocorticoid use. Symptoms of AI are non-specific, often overlooked or misdiagnosed, and are related to the lack of cortisol, adrenal androgen precursors and aldosterone (especially in PAI). Diagnosis is based on measurement of the adrenal corticosteroid hormones, their regulatory peptide hormones and stimulation tests. The goal of therapy is to establish a hormone replacement regimen that closely mimics the physiological diurnal cortisol secretion pattern, tailored to the patient's daily needs. This Primer provides insights into the epidemiology, mechanisms and management of AI during pregnancy as well as challenges of long-term management. In addition, the importance of identifying life-threatening adrenal emergencies (acute AI and adrenal crisis) is highlighted and strategies for prevention, which include patient education, glucocorticoid emergency cards and injection kits, are described.