Emodin improves glucose metabolism and ovarian function in PCOS mice via the HMGB1/TLR4/NF-κB molecular pathway.

In brief: Obese PCOS mice display metabolic and endocrine disorders that manifest as abnormal metabolism of glucose and dysfunctions in the reproductive system. This study demonstrates that emodin alleviates most of these conditions possibly via the HMGB1/TLR4/NF-kB pathway. Abstract: PCOS is a reproductive disorder with an unclear etiology. It affects 5-10% of women worldwide and is largely associated with impaired glucose metabolism and obesity. HMGB1 is a nuclear protein associated with impaired glucose metabolism and PCOS. We sought to investigate the potential therapeutic effects of emodin on glucose metabolism and ovarian functions in PCOS mice via the HMGB1 molecular pathway. A high-fat diet (HFD) and dehydroepiandrosterone (DHEA)- induced PCOS mouse model comprising four experimental groups was established: control, PCOS, PCOS plus emodin, and PCOS plus vehicle groups. Emodin administration attenuated obesity, elevated fasting glucose levels, impaired glucose tolerance, and insulin resistance, and improved the polycystic ovarian morphology of PCOS mice. Additionally, it lowered elevated serum HMGB1, LH, and testosterone levels in PCOS mice. Elevated ovarian protein and mRNA levels of HMGB1 and TLR4 in PCOS mice were also lowered following emodin treatment. Furthermore, emodin lowered high NF-ĸB/65 protein levels in the ovaries of PCOS mice. Immunohistochemical staining of the ovaries revealed strong HMGB1, TLR4, and AR expressions in PCOS mice, which were lowered by emodin treatment. Moreover, emodin significantly increased GLUT4, IRS2, and INSR levels that were lowered by PCOS. Overall, our study showed that emodin alleviated the impaired glucose metabolism and improved ovarian function in PCOS mice, possibly via the HMGB1/TLR4/NF-ĸB signaling pathway. Thus, emodin could be considered a potential therapeutic agent in the management of PCOS.

Glycyrrhizin ameliorates impaired glucose metabolism and ovarian dysfunction in a polycystic ovary syndrome mouse model.

The aim of this study was to determine the impact of glycyrrhizin, an inhibitor of high mobility group box 1, on glucose metabolic disorders and ovarian dysfunction in mice with polycystic ovary syndrome. We generated a polycystic ovary syndrome mouse model by using dehydroepiandrosterone plus high-fat diet. Glycyrrhizin (100 mg/kg) was intraperitoneally injected into the polycystic ovary syndrome mice and the effects on body weight, glucose tolerance, insulin sensitivity, estrous cycle, hormone profiles, ovarian pathology, glucolipid metabolism, and some molecular mechanisms were investigated. Increased number of cystic follicles, hormonal disorders, impaired glucose tolerance, and decreased insulin sensitivity in the polycystic ovary syndrome mice were reverted by glycyrrhizin. The increased high mobility group box 1 levels in the serum and ovarian tissues of the polycystic ovary syndrome mice were also reduced by glycyrrhizin. Furthermore, increased expressions of toll-like receptor 9, myeloid differentiation factor 88, and nuclear factor kappa B as well as reduced expressions of insulin receptor, phosphorylated protein kinase B, and glucose transporter type 4 were restored by glycyrrhizin in the polycystic ovary syndrome mice. Glycyrrhizin could suppress the polycystic ovary syndrome-induced upregulation of high mobility group box 1, several inflammatory marker genes, and the toll-like receptor 9/myeloid differentiation factor 88/nuclear factor kappa B pathways, while inhibiting the insulin receptor/phosphorylated protein kinase B/glucose transporter type 4 pathways. Hence, glycyrrhizin is a promising therapeutic agent against polycystic ovary syndrome.

CXC chemokines influence immune surveillance in immunological disorders: Polycystic ovary syndrome and endometriosis.

Reproductive health is a worldwide challenge, but it is of particular significance to women during their reproductive age. Several female reproductive problems, including polycystic ovary syndrome (PCOS) and endometriosis, affect about 10 % of women and have a negative impact on their health, fertility, and quality of life. Small, chemotactic, and secreted cytokines are CXC chemokines. Both PCOS and endometriosis demonstrate dysregulation of CXC chemokines, which are critical to the development and progression of both diseases. Recent research has shown that both in humans and animals, CXC chemokines tend to cause inflammation. It has also been found that CXC chemokines are necessary for promoting angiogenesis and inflammatory responses. CXC chemokine overexpression is frequently associated with poor survival and prognosis. CXC chemokine levels in PCOS and endometriosis patients impact their circumstances significantly. Hence, CXC chemokines have significant potential as diagnostic and prognostic biomarkers and therapeutic targets. The molecular mechanisms through which CXC chemokines promote inflammation and the development of PCOS and endometriosis are currently unknown. This article will discuss the functions of CXC chemokines in the promotion, development, and therapy of PCOS and endometriosis, as well as future research directions. The current state and future prospects of CXC chemokine -based therapeutic strategies in the management of PCOS and endometriosis are also highlighted.

Effects of Yulin Tong Bu formula on modulating gut microbiota and fecal metabolite interactions in mice with polycystic ovary syndrome.

Background: Polycystic ovarian syndrome (PCOS) is a common endocrine disorder characterized by hyperandrogenism, ovarian dysfunction and polycystic ovarian morphology. Gut microbiota dysbiosis and metabolite are associated with PCOS clinical parameters. Yulin Tong Bu formula (YLTB), a traditional Chinese medicine formula, has been recently indicated to be capable of ameliorating polycystic ovary symptoms and correcting abnormal glucose metabolism. However, the therapeutic mechanism of YLTB on PCOS has not been fully elucidated. Methods: A pseudo sterile mouse model was established during this four-day acclimatization phase by giving the animals an antibiotic cocktail to remove the gut microbiota. Here, the therapeutic effects of YLTB on PCOS were investigated using dehydroepiandrosterone plus high-fat diet-induced PCOS mice model. Female prepuberal mice were randomly divided into three groups; namely, the control group, PCOS group and YLTB (38.68 g·kg-1·day-1) group. To test whether this effect is associated with the gut microbiota, we performed 16S rRNA sequencing studies to analyze the fecal microbiota of mice. The relationships among metabolites, gut microbiota, and PCOS phenotypes were further explored by using Spearman correlation analysis. Then, the effect of metabolite ferulic acid was then validated in PCOS mice. Results: Our results showed that YLTB treatment ameliorated PCOS features (ovarian dysfunction, delayed glucose clearance, decreased insulin sensitivity, deregulation of glucolipid metabolism and hormones, etc.) and significantly attenuated PCOS gut microbiota dysbiosis. Spearman correlation analysis showed that metabolites such as ferulic acid and folic acid are negatively correlated with PCOS clinical parameters. The effect of ferulic acid was similar to that of YLTB. In addition, the bacterial species such as Bacteroides dorei and Bacteroides fragilis were found to be positively related to PCOS clinical parameters, using the association study analysis. Conclusion: These results suggest that YLTB treatment systematically regulates the interaction between the gut microbiota and the associated metabolites to ameliorate PCOS, providing a solid theoretical basis for further validation of YLTB effect on human PCOS trials.

Role of CPXM1 in Impaired Glucose Metabolism and Ovarian Dysfunction in Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS), a common female endocrinopathy associated with both reproductive and metabolic disorders, has an unclear etiology and unsatisfactory management methods. Carboxypeptidase X, M14 family member 1 (CPXM1) is a protein involved in follicular atresia, insulin production, and adipose tissue production, though its role in PCOS is not fully understood. We used a 60% high-fat diet (HFD) plus dehydroepiandrosterone (DHEA)-induced PCOS mouse model to determine the role of CPXM1 in abnormal glucose metabolism and ovarian dysfunction in PCOS. We found that serum CPXM1 concentrations were higher in PCOS mice and positively correlated with increased levels of serum testosterone and insulin. In both ovarian and adipose tissues of PCOS mice, CPXM1 mRNA and protein levels were significantly increased but GLUT4 levels were significantly decreased. Immunohistochemistry (IHC) staining of the ovary showed increased CPXM1 expression in PCOS. In addition, the protein expression of phosphorylated protein kinase B (p-Akt) was also significantly decreased in PCOS mice. Furthermore, mRNA levels of inflammatory markers such as TNF-α, IL-6, IFN-α, and IFN-γ were increased in ovarian and adipose tissues of PCOS mice. However, IRS-1, IRS-2, and INSR levels were significantly decreased. Our results indicated for the first time that abnormally high expression of CPXM1, increased adiposity, impaired glucose tolerance, and chronic low-grade inflammation may act together in a vicious cycle in the pathophysiology of PCOS. Our research suggests the possibility of CPXM1 as a potential therapeutic target for the treatment of PCOS.

CXCL13 and CXCR5 are upregulated in PCOS mice ovaries but downregulated following metformin administration.

Polycystic ovary syndrome (PCOS) is becoming a common pathology among women, yet its pathogenesis remains enigmatic. The chemokine C-X-C motif ligand 13 (CXCL13) and its receptor type 5 (CXCR5) regulate inflammatory responses but their roles in PCOS remain unknown. Metformin is commonly administered to PCOS patients but its mechanism of action remains unclear. Thus, we aimed to determine the expression of CXCL13 and CXCR5 in the ovaries of PCOS mice and to evaluate the therapeutic effect of metformin on them. The study comprised four groups of mice: control, PCOS, PCOS plus metformin, and PCOS plus vehicle. CXCL13 and CXCR5 were found to be elevated in the ovarian tissues of the PCOS mice. Metformin reduced ovarian CXCL13 and CXCR5 expressions in the PCOS mice. Hence, CXCL13 and CXCR5 are potentially involved in PCOS pathogenesis; and metformin may help alleviate the symptoms of PCOS by inhibiting CXCL13 expression and actions.

Ovarian inflammatory mRNA profiles of a dehydroepiandrosterone plus high-fat diet-induced polycystic ovary syndrome mouse model.

RESEARCH QUESTION: What is the expression pattern of inflammatory mRNA profiles of a dehydroepiandrosterone (DHEA) plus high-fat diet (HFD)-induced polycystic ovary syndrome (PCOS) mouse model? DESIGN: RNA sequencing was performed to investigate the mRNA expression profiles in the ovarian tissues of a DHEA plus HFD-induced PCOS mouse model. Six samples were divided into two groups (control and PCOS), with three biological replicates in each group. This was followed by hierarchical clustering, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. The relative expression levels of nine inflammatory genes were validated via quantitative reverse-transcription polymerase chain reaction. RESULTS: A total of 436 genes were differentially expressed between the control and PCOS mice. Out of these, 137 genes were up-regulated while 299 genes were down-regulated. Gene ontology analysis indicated that differentially expressed mRNA were associated with T cell-mediated cytotoxicity and homocysteine metabolic processes. Pathway analysis further showed that these abnormally expressed mRNA were associated with signalling pathways, such as NF-kB signalling, tyrosine metabolism and phenylalanine metabolism. All these pathways are involved in chronic inflammation and PCOS. CONCLUSION: The differentially expressed genes are potentially involved in the inflammation that is evident in PCOS, and so could serve as therapeutic options against the disease. Nevertheless, prospective studies are needed to test this hypothesis.

A decrease in cluster of differentiation 2 expression on natural killer cells is associated with polycystic ovary syndrome but not influenced by metformin in a mouse model†.

PROBLEM: Natural killer (NK) cells from the peripheral blood and spleen represent the source from which various tissues replenish their immune cell populations. Hyperandrogenism and high interleukin-2 (IL-2) levels are factors present in polycystic ovary syndrome (PCOS). These factors and metformin, one of the commonest medications used in treating PCOS, may have an impact on NK cells. However, this is presently unknown. Here, we aimed to assess the distribution of peripheral blood and splenic NK cells and their CD2 and CD94 expression patterns in a PCOS mouse model and test whether metformin could reverse these effects. METHOD OF STUDY: Four mouse groups were designed as follows (n = 15/group): control, PCOS, PCOS plus vehicle, PCOS plus metformin. Dehydroepiandrosterone and a high-fat diet were administered to induce the PCOS mouse model. Flow cytometry was used to analyze the expressions of CD2 and CD94 on peripheral blood and splenic NK cells. RESULTS: PCOS mice had a low surface-density of CD2 on peripheral blood NK cells and a decreased percentage of CD2+ splenic NK cells. Metformin administration did not significantly influence these changes; however, it reduced the splenic NK cell counts. CONCLUSIONS: Our findings proved the association of PCOS with an altered expression of CD2 on peripheral blood and splenic NK cells and that of metformin with a lowered splenic NK cell reserve in PCOS conditions. These findings could further unlock key mechanisms in PCOS pathophysiology and in the mechanism of action of metformin, towards improving PCOS management.

Contribution of high-fat diet-induced PCSK9 upregulation to a mouse model of PCOS is mediated partly by SREBP2.

The incidence of polycystic ovary syndrome (PCOS) due to high-fat diet (HFD) consumption has been increasing significantly. However, the mechanism by which a HFD contributes to the pathogenesis of PCOS has not been elucidated. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key protein that regulates cholesterol metabolism. Our previous study revealed abnormally high PCSK9 levels in serum from patients with PCOS and in serum and hepatic and ovarian tissues from PCOS model mice, suggesting that PCSK9 is involved in the pathogenesis of PCOS. However, the factor that induces high PCSK9 expression in PCOS remains unclear. In this study, Pcsk9 knockout mice were used to further explore the role of PCSK9 in PCOS. We also studied the effects of a HFD on the expression of PCSK9 and sterol regulatory element-binding protein 2 (SREBP2), a regulator of cholesterol homeostasis and a key transcription factor that regulates the expression of PCSK9, and the roles of these proteins in PCOS pathology. Our results indicated HFD may play an important role by inducing abnormally high PCSK9 expression via SREBP2 upregulation. We further investigated the effects of an effective SREBP inhibitor, fatostain, and found that it could reduce HFD-induced PCSK9 expression, ameliorate hyperlipidemia and improve follicular development in PCOS model mice. Our study thus further elucidates the important role of an HFD in the pathogenesis of PCOS and provides a new clue in the prevention and treatment of this disorder.