The role of adiponectin in reproduction: from polycystic ovary syndrome to assisted reproduction

The association between leptin, adiponectin levels and the ovarian reserve in women of reproductive age

Background

Reproduction ability requires a certain amount of body fat that is necessary for ovulation, menstruation and pregnancy. Fat tissue represents an endocrine organ with high metabolic activity as it produces adipokines such as leptin and adiponectin. Our aim is to examine potential associations between women of reproductive age's ovarian reserves and their levels of leptin and adiponectin.

Method

74 women between 19 and 40 years of age consented to take part. Based on the patterns of their ovarian reserves, the women were divided into three main groups: women with adequate ovarian reserves (AOR - Group A, n=30), women with polycystic ovary syndrome (PCOS - Group B, n=31) and women with depleted ovarian reserves (DOR - Group C, n=13). Among these groups, several biochemical and demographic parameters were statistically compared.

Results

Compared to the other two groups, women with DOR had statistically higher age and follicle stimulation hormone (FSH) levels. For estradiol (E2) and thyroid-stimulating hormone (TSH), no statistically significant difference was seen between the groups. In addition, women with PCOS had higher body mass index (BMI), luteinizing hormone (LH), total testosterone (TT), 17 hydroxyprogesterone (17-OHP), dehydroepiandrosterone (DHEA), anti-Mullerian hormone (AMH), and antral follicle count (AFC) than the other two groups. In line with expectations, women with DOR also had lower levels of AMH and AFC than the other two groups. Women with PCOS had higher leptin levels than the other two groups, but there was no statistically significant difference. Women with PCOS had lower levels of adiponectin than the other groups, however the difference was not statistically significant.

Conclusion

The way we classified women in our study according to their ovarian reserves is completely consistent with what has been published internationally. The ovarian reserve in women of reproductive age is not strongly correlated with leptin and adiponectin levels. For safe conclusions, more research including a greater number of samples is required.

[Adiponectin improves endometrial receptivity in rats with polycystic ovary syndrome by upregulating the PPARα/HOXA10 pathway]

OBJECTIVE

To explore the role of the PPARα/HOXA10 signaling pathway in mediating the effect of adiponectin (APN) for improving endometrial receptivity in a rat model of polycystic ovary syndrome (PCOS).

METHODS

Forty female SD rat models with letrozole-induced PCOS were randomized, with 10 normal rats as the control, into 4 equal groups for treatment with APN alone, APN combined with GW6471 (a specific PPARα inhibitor) or the vehicle for 20 days, or no further treatment (PCOS model group). GW6471 treatment (daily dose of 1 mg/kg) and vehicle treatment were initiated on the 11th day following the start of APN treatment, all administered via intraperitoneal injection. The rats were observed for changes in estrous cycle, body weight, ovarian index and morphology, uterine index and morphology, serum hormone levels and lipid metabolism parameters. Endometrial expressions of PPARα and HOXA10 were detected with immunohistochemistry and Western blotting. The development of endometrial pinopodes was observed under electron microscope, and pregnancies of the rats were recorded.

RESULTS

The rat models of PCOS exhibited obvious estrous cycle disorders with significantly prolonged estrous interval, increased body weight and ovarian index, decreased uterine index, disordered serum hormones and lipid metabolism (P < 0.05), and polycystic ovarian changes, and these changes were significantly improved by APN treatment. Endometrial expressions of PPARα and HOXA10 were significantly lowered in PCOS rats and effectively up-regulated after APN treatment, but GW6471 treatment obviously blocked the effect of APN (P < 0.05). APN showed strong protective effect against PCOS-induced impairment of endometrial pinopode development, and this effect was obviously attenuated by GW6471. APN also significantly increased the pregnancy rate and embryo number in PCOS rats, while GW6471 obviously reduced the embryo number and caused developmental retardation of the embryos.

CONCLUSION

APN can improve endometrial receptivity in PCOS rats by upregulating the PARα/HOXA10 pathway.

White-brown adipose tissue interplay in polycystic ovary syndrome: Therapeutic avenues

This study highlights the therapeutic potential of activating brown adipose tissue (BAT) for managing polycystic ovary syndrome (PCOS), a prevalent endocrine disorder associated with metabolic and reproductive abnormalities. BAT plays a crucial role in regulating energy expenditure and systemic insulin sensitivity, making it an attractive target for the treatment of obesity and metabolic diseases. Recent research suggests that impaired BAT function and mass may contribute to the link between metabolic disturbances and reproductive issues in PCOS. Additionally, abnormal white adipose tissue (WAT) can exacerbate these conditions by releasing adipokines and nonesterified fatty acids. In this review, we explored the impact of WAT changes on BAT function in PCOS and discussed the potential of BAT activation as a therapeutic strategy to improve PCOS symptoms. We propose that BAT activation holds promise for managing PCOS; however, further research is needed to confirm its efficacy and to develop clinically feasible methods for BAT activation.

Impose of KNDy/GnRH neural circuit in PCOS, ageing, cancer and Alzheimer's disease: StAR actions in prevention of neuroendocrine dysfunction

The Kisspeptin1 (KISS1)/neurokinin B (NKB)/Dynorphin (Dyn) [KNDy] neurons in the hypothalamus regulate the reproduction stage in human beings and rodents. KNDy neurons co-expressed all KISS1, NKB, and Dyn peptides, and hence commonly regarded as KISS1 neurons. KNDy neurons contribute to the "GnRH pulse generator" and are implicated in the regulation of pulsatile GnRH release. The estradiol (E2)-estrogen receptor (ER) interactions over GnRH neurons in the hypothalamus cause nitric oxide (NO) discharge, in addition to presynaptic GABA and glutamate discharge from respective neurons. The released GABA and glutamate facilitate the activity of GnRH neurons via GABAA-R and AMPA/kainate-R. The KISS1 stimulates MAPK/ERK1/2 signaling and cause the release of Ca2+ from intracellular store, which contribute to neuroendocrine function, increase apoptosis and decrease cell proliferation and metastasis. The ageing in women deteriorates KISS1/KISS1R interaction in the hypothalamus which causes lower levels of GnRH. Because examining the human brain is so challenging, decades of clinical research have failed to find the causes of KNDy/GnRH dysfunction. The KISS1/KISS1R interactions in the brain have a neuroprotective effect against Alzheimer's disease (AD). These findings modulate the pathophysiological role of the KNDy/GnRH neural network in polycystic ovarian syndrome (PCOS) associated with ageing and, its protective role in cancer and AD. This review concludes with protecting effect of the steroid-derived acute regulatory enzyme (StAR) against neurotoxicity in the hippocampus, and hypothalamus, and these measures are fundamental for delaying ageing with PCOS. StAR could serve as novel diagnostic marker and therapeutic target for the most prevalent hormone-sensitive breast cancers (BCs).

Goldfish adiponectin: (I) molecular cloning, tissue distribution, recombinant protein expression, and novel function as a satiety factor in fish model

Adiponectin (AdipoQ) is an adipokine involved in glucose homeostasis and lipid metabolism. In mammals, its role in appetite control is highly controversial. To shed light on the comparative aspects of AdipoQ in lower vertebrates, goldfish was used as a model to study feeding regulation by AdipoQ in fish species. As a first step, goldfish AdipoQ was cloned and found to be ubiquitously expressed at the tissue level. Using sequence alignment, protein modeling, phylogenetic analysis and comparative synteny, goldfish AdipoQ was shown to be evolutionarily related to its fish counterparts and structurally comparable with AdipoQ in higher vertebrates. In our study, recombinant goldfish AdipoQ was expressed in E. coli, purified by IMAC, and confirmed to be bioactive via activation of AdipoQ receptors expressed in HepG2 cells. Feeding in goldfish revealed that plasma levels of AdipoQ and its transcript expression in the liver and brain areas involved in appetite control including the telencephalon, optic tectum, and hypothalamus could be elevated by food intake. In parallel studies, IP and ICV injection of recombinant goldfish AdipoQ in goldfish was effective in reducing foraging behaviors and food consumption. Meanwhile, transcript expression of orexigenic factors (NPY, AgRP, orexin, and apelin) was suppressed with parallel rises in anorexigenic factors (POMC, CART, CCK, and MCH) in the telencephalon, optic tectum and/or hypothalamus. In these brain areas, transcript signals for leptin receptor were upregulated with concurrent drops in the NPY receptor and ghrelin receptors. In the experiment with IP injection of AdipoQ, transcript expression of leptin was also elevated with a parallel drop in ghrelin mRNA in the liver. These findings suggest that AdipoQ can act as a novel satiety factor in goldfish. In this case, AdipoQ signals (both central and peripheral) can be induced by feeding and act within the brain to inhibit feeding behaviors and food intake via differential regulation of orexigenic/anorexigenic factors and their receptors. The feeding inhibition observed may also involve the hepatic action of AdipoQ by modulation of feeding regulators expressed in the liver.

Local Expression Dynamics of Various Adipokines during Induced Luteal Regression (Luteolysis) in the Bovine Corpus Luteum

The study aimed to evaluate the mRNA expression levels of various local novel adipokines, including vaspin, adiponectin, visfatin, and resistin, along with their associated receptors, heat shock 70 protein 5, adiponectin receptor 1, and adiponectin receptor 2, in the corpus luteum (CL) during luteal regression, also known as luteolysis, in dairy cows. We selected Fleckvieh cows in the mid-luteal phase (days 8-12, control group) and administered cloprostenol (PGF analog) to experimentally induce luteolysis. We collected CL samples at different time points following PGF application: before treatment (days 8-12, control group) and at 0.5, 2, 4, 12, 24, 48, and 64 h post-treatment (n = 5) per group. The mRNA expression was measured via real-time reverse transcription polymerase chain reaction (RT-qPCR). Vaspin was characterized by high mRNA levels at the beginning of the regression stage, followed by a significant decrease 48 h and 64 h after PGF treatment. Adiponectin mRNA levels were elevated 48 h after PGF. Resistin showed upregulation 4 h post PGF application. In summary, the alterations observed in the adipokine family within experimentally induced regressing CL tissue potentially play an integral role in the local regulatory processes governing the sequence of events culminating in functional luteolysis and subsequent structural changes in the bovine ovary.

Role of leptin, adiponectin, and kisspeptin in polycystic ovarian syndrome pathogenesis

INTRODUCTION

Polycystic ovarian syndrome (PCOS) affects 5-20% of females and is the most common cause of anovulatory infertility. Leptin seems to have an important role in reproduction. Many reproductive pathologies such as preeclampsia, PCOS, and endometriosis are associated to plasma adiponectin levels. Kisspeptin levels are increased in PCOS women.

EVIDENCE ACQUISITION

A review of the literature was completed through the PubMed database aiming to find articles regarding leptin, adiponectin and kisspeptin and if they are related to PCOS pathogenesis.

EVIDENCE SYNTHESIS

Even today it is not clear what is the role of leptin in women with PCOS, although most of the researchers found increased levels of leptin as well as leptin resistance in PCOS (both obese and lean individuals). Many more longitudinal studies should be done to discover the usefulness of measuring adiponectin in prepubertal women who apparently have a possibility to develop PCOS to find out if they finally develop PCOS. Most of the researchers found that PCOS women have decreased levels of adiponectin unrelated to BMI levels. Nevertheless, not all studies had the same result. Moreover, it is necessary more studies to be made to investigate the connection between kisspeptin and other metabolic factors such as LH and insulin resistance.

CONCLUSIONS

In general, it remains inconclusive whether leptin, adiponectin, and kisspeptin can be used as clinical and/or biochemical markers of PCOS. Therefore, it is essential to review the current data with regards to the association between PCOS and circulating leptin, adiponectin, and kisspeptin in women with PCOS.

Role of Leptin and Adiponectin in Carcinogenesis

Hormones produced by adipocytes, leptin and adiponectin, are associated with the process of carcinogenesis. Both of these adipokines have well-proven oncologic potential and can affect many aspects of tumorigenesis, from initiation and primary tumor growth to metastatic progression. Involvement in the formation of cancer includes interactions with the tumor microenvironment and its components, such as tumor-associated macrophages, cancer-associated fibroblasts, extracellular matrix and matrix metalloproteinases. Furthermore, these adipokines participate in the epithelial-mesenchymal transition and connect to angiogenesis, which is critical for cancer invasiveness and cancer cell migration. In addition, an enormous amount of evidence has demonstrated that altered concentrations of these adipocyte-derived hormones and the expression of their receptors in tumors are associated with poor prognosis in various types of cancer. Therefore, leptin and adiponectin dysfunction play a prominent role in cancer and impact tumor invasion and metastasis in different ways. This review clearly and comprehensively summarizes the recent findings and presents the role of leptin and adiponectin in cancer initiation, promotion and progression, focusing on associations with the tumor microenvironment and its components as well as roles in the epithelial-mesenchymal transition and angiogenesis.

Exploring molecular dynamic indicators associated with reproductive performance of Bos indicus cattle in blood plasma samples through data-independent acquisition mass spectrometry

Improving reproductive performance of cattle is of paramount importance for sustainable dairy farming. Poor reproduction performance (RP) hinders the genetic improvement of important Bos indicus cattle breeds. It is well known that incorporation of molecular information along with conventional breeding method is far better than use of conventional method alone for the genetic improvement of reproductive performance traits in cattle. Therefore, the present study sought to investigate the plasma proteome of the Deoni cows in cyclical (n = 6) and pregnant (n = 6) reproductive phases with varying reproductive performance (high and low). High-throughput data independent acquisition (DIA) based proteomics was performed to understand corresponding proteome. We identified a total of 430 plasma proteins. Among cyclic cows, twenty proteins were differentially regulated in low RP as compared to high RP. BARD1 and AFP proteins were observed upregulated in cyclical cows whose upregulation reported to affect reproductive performance in cattle. Among the pregnant cows, thirty-five proteins were differentially regulated, including the downregulation of FGL2 and ZNFX1 that modulates the maternal immune response mechanism which is required for successful implantation of the embryo. Also, proteins such as AHSG, CLU and SERPINA6 were upregulated in the pregnant cows whose upregulation reported to reduced reproductive performance. The results of this study will be helpful in establishing a framework for future research on the aspect of improving reproductive performance in Bos indicus cattle breeds. SIGNIFICANCE: The Indian subcontinent is the center of domestication for Bos indicus cattle breeds and they are known for their disease resistance, heat tolerance, ability to survive in low input regime and harsh climatic conditions. In recent times, population of many important Bos indicus breeds including Deoni cattle is declining due to various factors, especially due to reproductive performance. Traditional breeding methods are not sufficient enough to understand and improve the reproductive performance traits in important Bos indicus cattle breeds. Proteomics approach is a promising technology to understand the complex biological factors which leads to poor reproductive performance in cattle. The present study utilized DIA based LC- MS/MS analysis to identify the plasma proteins associated with reproductive performance in cyclical and pregnant cows. This study if improved further, can be used to develop potential protein markers associated with reproductive performance which is useful for the selection and genetic improvement of important Bos indicus breeds.

Immunological and Metabolic Causes of Infertility in Polycystic Ovary Syndrome

Infertility has been recognized as a civilizational disease. One of the most common causes of infertility is polycystic ovary syndrome (PCOS). Closely interrelated immunometabolic mechanisms underlie the development of this complex syndrome and lead to infertility. The direct cause of infertility in PCOS is ovulation and implantation disorders caused by low-grade inflammation of ovarian tissue and endometrium which, in turn, result from immune and metabolic system disorders. The systemic immune response, in particular the inflammatory response, in conjunction with metabolic disorders, insulin resistance (IR), hyperadrenalism, insufficient secretion of progesterone, and oxidative stress lead not only to cardiovascular diseases, cancer, autoimmunity, and lipid metabolism disorders but also to infertility. Depending on the genetic and environmental conditions as well as certain cultural factors, some diseases may occur immediately, while others may become apparent years after an infertility diagnosis. Each of them alone can be a significant factor contributing to the development of PCOS and infertility. Further research will allow clinical management protocols to be established for PCOS patients experiencing infertility so that a targeted therapy approach can be applied to the factor underlying and driving the "vicious circle" alongside symptomatic treatment and ovulation stimulation. Hence, therapy of fertility for PCOS should be conducted by interdisciplinary teams of specialists as an in-depth understanding of the molecular relationships and clinical implications between the immunological and metabolic factors that trigger reproductive system disorders is necessary to restore the physiology and homeostasis of the body and, thus, fertility, among PCOS patients.

Expression of Locally Produced Adipokines and Their Receptors during Different Physiological and Reproductive Stages in the Bovine Corpus Luteum

This study aimed to determine the gene expression of different local novel adipokines, such as vaspin, adiponectin, visfatin, and resistin, and their known receptors, namely, heat shock 70 protein 5, adiponectin receptor 1, and adiponectin receptor 2, in the bovine corpus luteum (CL) during different phases of the estrous cycle (on days 1-2, 3-4, 5-7, 8-12, 13-18, >18) and pregnancy (at months 1-2, 3-4, 5-7, >7). The mRNA expression was measured by reverse transcription polymerase chain reaction (RT-qPCR). The mRNA expression levels were normalized to the geometric mean of all three constantly expressed reference genes (cyclophilin A, ubiquitin, ubiquitin C). Our findings suggest that adipokines are expressed and present in all investigated groups, and are specifically up- or downregulated during the estrus cycle and during pregnancy. Vaspin and adiponectin levels were upregulated in the middle and late cycle stages. Resistin was abundant during the CL regression stage and in the first months of pregnancy. The specific expression of adipokine receptors indicates their involvement in the local mechanisms that regulate CL function. Further investigations are required to elucidate the regulative mechanisms underlying the different local effects of adipokines on the ovarian physiology of cows.

Intrauterine androgen exposure impairs gonadal adipose tissue functions of adult female rats

Prenatal androgen exposure induces fetal programming leading to alterations in offspring health and phenotypes that resemble those seen in women with Polycystic Ovary Syndrome. It has been described that prenatal androgenization affects the reproductive axis and leads to metabolic and endocrine disorders. Adipose tissue plays a crucial role in all these functions and is susceptible to programming effects. Particularly, gonadal adipose tissue is involved in reproductive functions, so dysfunctions in this tissue could be related to fertility alterations. We aimed to investigate the extent to which prenatal hyperandrogenization is able to alter the functionality of gonadal adipose tissue in female adult rats, including lipid metabolism, adipokines expression, and de novo synthesis of steroids. Pregnant rats were treated with 1 mg of testosterone from day 16 to day 19 of pregnancy, and female offspring were followed until 90 days of age, when they were euthanized. The prenatally hyperandrogenized (PH) female offspring displayed two phenotypes: irregular ovulatory (PHiov) and anovulatory (PHanov). Regarding lipid metabolism, both PH groups displayed disruptions in the main lipid pathways with altered levels of triglyceride and increased lipid peroxidation levels. In addition, we found that Peroxisome Proliferator-Activated Receptors (PPARs) alpha protein expression was decreased in both PH phenotypes (p < 0.05), but no changes were found in PPARγ protein levels. Furthermore, regarding adipokines, no changes were found in Leptin and Adiponectin protein levels, but Chemerin protein levels were decreased in the PHiov group (p < 0.05). Regarding de novo synthesis of steroids, the PHanov group showed increased protein levels of Cyp17a1 and Cyp19, while the PHiov group only showed decreased protein levels of Cyp19 (p < 0.05). These results suggest that prenatal androgen exposure affects females' gonadal adipose tissue in adulthood, disturbing different lipid pathways, Chemerin expression, and de novo synthesis of steroids.

Integrated Transcriptome Analysis Reveals the Crucial mRNAs and miRNAs Related to Fecundity in the Hypothalamus of Yunshang Black Goats during the Luteal Phase

A normal estrus cycle is essential for the breeding of goats, and the luteal phase accounts for most of the estrus cycle. The corpus luteum (CL) formed during the luteal phase is a transient endocrine gland that is crucial for the reproductive cycle and pregnancy maintenance, and is controlled by many regulatory factors. However, the molecular mechanism of the hypothalamus effect on the reproductive performance of different litter sizes during the luteal phase of goats has not been elucidated. In this study, RNA-sequencing was used to analyze the mRNA and miRNA expression profiles of the hypothalamic tissues with the high-fecundity goats during the luteal phase (LP-HF) and low-fecundity goats during the luteal phase (LP-LF). The RNA-seq results found that there were 1963 differentially expressed genes (DEGs) (890 up-regulated and 1073 down-regulated). The miRNA-seq identified 57 differentially expressed miRNAs (DEMs), including 11 up-regulated and 46 down-regulated, of which 199 DEGs were predicted to be potential target genes of DEMs. Meanwhile, the functional enrichment analysis identified several mRNA-miRNA pairs involved in the regulation of the hypothalamic activity, such as the common target gene MEA1 of novel-miR-972, novel-miR-125 and novel-miR-403, which can play a certain role as a related gene of the reproductive development in the hypothalamic-pituitary-gonadal (HPG) axis and its regulated network, by regulating the androgen secretion. While another target gene ADIPOR2 of the novel-miR-403, is distributed in the hypothalamus and affects the reproductive system through a central role on the HPG axis and a peripheral role in the gonadal tissue. An annotation analysis of the DE miRNA-mRNA pairs identified targets related to biological processes, such as anion binding (GO:0043168) and small molecule binding (GO: 0036094). Subsequently, the KEGG(Kyoto Encyclopedia of Genes and Genomes) pathways were performed to analyze the miRNA-mRNA pairs with negatively correlated miRNAs. We found that the GnRH signaling pathway (ko04912), the estrogen signaling pathway (ko04915), the Fc gamma R-mediated phagocytosis (ko04666), and the IL-17 signaling pathway (ko04657), etc., were directly and indirectly associated with the reproductive process. These targeting interactions may be closely related to the reproductive performance of goats. The results of this study provide a reference for further research on the molecular regulation mechanism for the high fertility in goats.

Transcriptomic analysis of the thyroid and ovarian stroma reveals key pathways and potential candidate genes associated with egg production in ducks

The importance of thyroid-related genes has been repeatedly mentioned in the transcriptome studies of poultry with different laying performance, yet there are few systematic studies to unravel the regulatory mechanisms of the thyroid-ovary axis in the poultry egg production process. In this study, we compared the transcriptome profiles in the thyroid and ovarian stroma between high egg production (GP) and low egg production (DP) ducks, and then revealed the pathways and candidate genes involved in the process. We identified 1,114 and 733 differentially expressed genes (DEGs) in the thyroid and ovarian stroma, separately. The Gene Ontology (GO) analysis showed that a total of 504 and 189 GO terms were identified in the thyroid and ovarian stroma (P < 0.05). Three common GO terms were identified from the top 5 GO terms with the highest significant level in two tissues, including extracellular space, calcium ion binding, and integral component of plasma membrane. The enrichment analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that 15 and 14 KEGG pathways were significantly (P < 0.05) enriched in the thyroid and ovarian stroma, respectively. And, there were 8 common pathways, including neuroactive ligand-receptor interaction, calcium signaling pathway, ECM-receptor interaction, PPAR signaling pathway, melanogenesis, wnt signaling pathway, vascular smooth muscle contraction, and cytokine-cytokine receptor interaction. Notably, the neuroactive ligand-receptor interaction pathway was the most significantly enriched by the DEGs both in the thyroid and ovarian stroma. The interaction among DEGs enriched in the neuroactive ligand-receptor interaction and ECM-receptor interaction suggested that the thyroid may regulate ovarian development by these genes. Through integrated analysis of the protein-protein interaction (PPI) network and KEGG pathway maps, 9 key DEGs (PTH, THBS2, THBS4, CD36, ADIPOQ, ACSL6, PRKAA2, CRH, and PCK1) were identified, which could play crucial roles in the thyroid to regulate ovarian function and then affect egg-laying performance between GP and DP. This study serves as a basis to explore the molecular mechanism of the thyroid affecting ovarian function and egg production in female ducks and may help to identify molecular markers that can be used for duck genetic selection.

Role of adipokines in embryo implantation

Embryo implantation is a complex process in which multiple molecules acting together under strict regulation. Studies showed the production of various adipokines and their receptors in the embryo and uterus, where they can influence the maternal-fetal transmission of metabolites and embryo implantation. Therefore, these cytokines have opened a novel area of study in the field of embryo-maternal crosstalk during early pregnancy. In this respect, the involvement of adipokines has been widely reported in the regulation of both physiological and pathological aspects of the implantation process. However, the information about the role of some recently identified adipokines is limited. This review aims to highlight the role of various adipokines in embryo-maternal interactions, endometrial receptivity, and embryo implantation, as well as the underlying molecular mechanisms.

Effect of adiponectin on estradiol and progesterone secretion from human luteinized granulosa cells in vitro

Ιnformation on the role of adiponectin in human ovarian steroidogenesis is limited. The present study aimed to investigate the effect of different doses of adiponectin on the secretion of estradiol and progesterone by human luteinized granulosa cells in culture. Granulosa cells, obtained from women undergoing in vitro fertilization (IVF) treatment, were pre-incubated for 24 h and then cultured for 48 h. Adiponectin was used in 3 doses, i.e., 5, 10, and 100 μg/ml alone and in combinations with FSH (10 and 100 ng/ml). Estradiol and progesterone were measured by radioimmunoassays in culture supernatants at 24 h and 48 h. Adiponectin after 48 h of culture stimulated the secretion of estradiol and, to a lesser extent, progesterone in a dose-dependent manner. FSH showed a variable effect on steroidogenesis. However, when the low dose FSH was combined with adiponectin, estradiol, and progesterone secretion were increased disproportionally to the dose of adiponectin. With the high dose FSH, the positive effect of adiponectin on FSH-induced estradiol secretion was less pronounced, while the effect on progesterone secretion was negligible. This study shows for the first time a stimulatory effect of adiponectin on the secretion of estradiol and progesterone by human luteinized granulosa cells in vitro. It is suggested that adiponectin plays a paracrine role in human ovarian steroidogenesis by sensitizing the granulosa cells to FSH.

Effect of turmeric on adiponectin, sexual function and sexual hormones in stressed mice

Sexual function is essential for species survival. Melanocortin, progesterone, and estrogen can improve sexual function and they are modulated by adiponectin hormone which can be increased by Turmeric. In various studies shows Turmeric ability that is easily accessible to increase serum adiponectin levels. Therefore, the researchers decided to conduct a study to determine the effect of turmeric on serum adiponectin levels, sexual behavior, and profile of steroid hormones in stressed mice. Thirty female mice, six in each group (1. control group, 2. mice that received stress, 3. stress mice received 100 mg/kg turmeric (extract daily) for 4 weeks, 4. stress mice received turmeric (extract daily) for 4 weeks and also received adiponectin antagonist, and 5. stress groups received adiponectin antagonist), were used in the current study. The mice first underwent blood sampling. Then all mice were subjected to stress testing before the intervention except one group, which considered as a control group. The intervention in this study was done as a 100 mg/kg turmeric extract that was gavaged daily for each mouse. After the intervention, all mice were tested for sexual behavior, and then blood samples were taken to check serum levels of adiponectin, estradiol, progesterone and prolactin. So, the results showed before the intervention there were no significant difference among 5 group in levels of adiponectin (p = 0.145), estradiol (p = 0.148), progesterone (p = 0.166) and prolactin (p = 0.206) but after intervention there were significant difference between 5 group in levels of adiponectin, estradiol and progesterone (p < 0.001). Also there was significant difference among 5 groups in sexual behavior (p < 0.001). Therefore, consumption of turmeric, which increases serum adiponectin in the stressed mice, can improve sexual function and estradiol hormones profiling.

Chronic niacin administration ameliorates ovulation, histological changes in the ovary and adiponectin concentrations in a rat model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common ovarian diseases among women of reproductive age. The reproductive and metabolic traits of PCOS are underpinned by adipocyte dysfunction, especially diminished adiponectin secretion. Based on evidence that niacin stimulates adiponectin secretion, this study evaluated the effects of niacin on adiponectin concentrations and reproductive traits in a rat model of PCOS. PCOS was induced by single injection of 4mg kg-1 oestradiol valerate (i.m.), and PCOS groups were administered orally with saline or niacin (10 or 25mg kg-1) daily for 30 days after PCOS induction. The control group received 0.2mL sesame oil (i.m.) only. At the end of the experimental period, serum samples and ovaries were collected for adiponectin, histological and molecular analyses. Niacin reduced the bodyweight gain and increased ovary weights in PCOS rats. Niacin also increased the number of normal antral follicles and corpora lutea while reducing the number of cystic follicles and the thickness of theca interna. Moreover, niacin significantly increased serum adiponectin concentration and the gene expression of adiponectin and its type 1 receptor. In conclusion, this study indicates that niacin reduces cystic follicles and improves ovulation in PCOS rats. Adiponectin signalling may have contributed, in part, to the beneficial effects.

Adipocyte and steroidogenic cell cross-talk in polycystic ovary syndrome

BACKGROUND

Metabolic and endocrine alterations in women with polycystic ovary syndrome (PCOS) affect adipose tissue mass and distribution. PCOS is characterised by hyperandrogenism, obesity and adipocyte dysfunction. Hyperandrogenism in PCOS drives dysfunctional adipocyte secretion of potentially harmful adipocytokines. Glucocorticoids and sex-steroids modulate adipocyte development and function. For their part, adipocyte products interact with adrenal and ovarian steroidogenic cells. Currently, the relationship between adipocyte and steroidogenic cells is not clear, and for these reasons, it is important to elucidate the interrelationship between these cells in women with and without PCOS.

OBJECTIVE AND RATIONALE

This comprehensive review aims to assess current knowledge regarding the interrelationship between adipocytes and adrenal and ovarian steroidogenic cells in animal models and humans with or without PCOS.

SEARCH METHODS

We searched for articles published in English and Portuguese in PubMed. Keywords were as follows: polycystic ovary syndrome, steroidogenesis, adrenal glands, theca cells, granulosa cells, adipocytes, adipocytokines, obesity, enzyme activation, and cytochrome P450 enzymes. We expanded the search into the references from the retrieved articles.

OUTCOMES

Glucocorticoids and sex-steroids modulate adipocyte differentiation and function. Dysfunctional adipocyte products play important roles in the metabolic and endocrine pathways in animals and women with PCOS. Most adipokines participate in the regulation of the hypothalamic-pituitary-adrenal and ovarian axes. In animal models of PCOS, hyperinsulinemia and poor fertility are common; various adipokines modulate ovarian steroidogenesis, depending on the species. Women with PCOS secrete unbalanced levels of adipocyte products, characterised by higher levels of leptin and lower levels of adiponectin. Leptin expression positively correlates with body mass index, waist/hip ratio and levels of total cholesterol, triglyceride, luteinising hormone, oestradiol and androgens. Leptin inhibits the production of oestradiol and, in granulosa cells, may modulate 17-hydroxylase and aromatase enzyme activities. Adiponectin levels negatively correlate with fat mass, body mass index, waist-hip ratio, glucose, insulin and triglycerides, and decrease androgen production by altering expression of luteinising hormone receptor, steroidogenic acute regulatory protein, cholesterol-side-chain cleavage enzyme and 17-hydroxylase. Resistin expression positively correlates with body mass index and testosterone, and promotes the expression of 17-hydroxylase enzyme in theca cells. The potential benefits of adipokines in the treatment of women with PCOS require more investigation.

WIDER IMPLICATIONS

The current data regarding the relationship between adipocyte products and steroidogenic cells are conflicting in animals and humans. Polycystic ovary syndrome is an excellent model to investigate the interrelationship among adipocyte and steroidogenic cells. Women with PCOS manifest some pathological conditions associated with hyperandrogenism and adipocyte products. In animals, cross-talk between cells may vary according to species, and the current review suggests opportunities to test new medications to prevent or even reverse several harmful sequelae of PCOS in humans. Further studies are required to investigate the possible therapeutic application of adipokines in women with obese and non-obese PCOS. Meanwhile, when appropriate, metformin use alone, or associated with flutamide, may be considered for therapeutic purposes.

Ovarian Transcriptomic Analysis Reveals Differential Expression Genes Associated with Cell Death Process after Selection for Ovulation Rate in Rabbits

Simple Summary

Transcriptomic analysis showed nineteen potential biomarkers in ovarian tissue from females belonged to a rabbit line selected for ovulation rate for 10 generations and the control line. These females differed not only in ovulation rate but also in prenatal survival since similar litter size were observed.

Abstract

Litter size is an essential trait in rabbit meat production but with low heritability. A selection experiment for ovulation rate has been performed for 10 generations to improve litter size in rabbits. The selected line increased two ova more than the control line but nevertheless a negative correlation was observed with prenatal survival. A transcriptomic study was performed, using microarrays, in ovarian tissue from females belonging to the selected line and the control line. Our results showed 1357 differential expressed genes and nineteen potential biomarkers associated with prenatal mortality, which could explain differences between litter size in rabbits. Cell death was the most relevant process.

Time-restricted feeding improves the reproductive function of female mice via liver fibroblast growth factor 21

Background

There has been a significant increase, to epidemic levels, of obese and overweight women of reproductive age, causing impairments to reproductive health. Time‐restricted feeding (TRF) including isocaloric intake has shown to be preventive of obesity‐related disorders. However, its therapeutic ability to improve the reproductive function of female remains largely unknown.

Methods

Here, we investigated the ability of TRF to improve the reproductive function in wild‐type and liver‐specific FGF21 knockout female mice. To study fertility, a continuous and a short‐term fertility test, gonadotropin releasing‐hormone (GnRH), and Kisspeptin test were performed. Immortalized GnRH neuron was used to examine the direct role of liver fibroblast growth factor 21 (FGF21) on GnRH secretion.

Results

We found that TRF rescues female mice from bodyweight gain and glucose intolerance, as well as ovarian follicle loss and dysfunction of estrus cyclicity induced by high‐fat diet. Furthermore, the beneficial effects of the TRF regimen on the reproductive performance were also observed in mice fed both chow and high‐fat diet. However, those beneficial effects of TRF on metabolism and reproduction were absent in liver‐specific FGF21 knockout mice. In vitro, FGF21 directly acted on GnRH neurons to modulate GnRH secretion via extracellular regulated protein kinases (ERK_1/2) pathway.

Conclusions

Overall, time‐restricted feeding improves the reproductive function of female mice and liver FGF21 signaling plays a key role in GnRH neuron activity in female mice.

Endocrine approach in the treatment of obesity: Is there any space for the adiponectin action?

Adiponectin is a hormone secreted by adipose tissue, exerting many positive effects in the human body. Its action has been widely studied, placing it into the metabolic health beneficial products of the adipose tissue. Nevertheless, adiponectin has been shown to exert some extra beneficial non metabolic actions, as well. Adiponectin levels can be related to reduced incidence of cancer in obese patients. Moreover, adiponectin has been shown to be implicated in the positive fertility outcomes of women. Some new studies have also indicated that adiponectin has a potential effect in the control of appetite, which raises a question, whether adiponectin could be accredited to be useful in the endocrine evaluation of obesity. Could these additional non-metabolic actions prove its helpfulness?

Recombinant adiponectin alleviates abortion in mice by regulating Th17/Treg imbalance via p38MAPK-STAT5 pathway

Recurrent spontaneous abortion is associated with abnormal maternal tolerance to the semi-allogenic fetus, wherein the Th17/Treg axis plays a crucial role. Adiponectin (APN) is an adipocytokine that is shown to be a novel negative T-cell regulator and induce immune tolerance. The CBA/J × DBA/2 mating was used as an abortion-prone model to investigate whether the addition of recombinant adiponectin (rAPN) improves the pregnancy outcome. Recombinant adiponectin therapy reduced the abortion rate in abortion-prone model. It skewed the ability of serum cytokine production toward a Treg bias and induced APN production. Flow cytometry revealed that rAPN administration expanded the splenic CD4+CD25+ regulatory T-cell (Treg) population and reduced the Th17 cell populations in CBA/J × DBA/2 matings. RT-PCR revealed that rAPN administration induced the expression of AdipoR1 and AdipoR2 mRNA at the maternofetal interface. Recombinant adiponectin administration induced FoxP3 and reduced RORγt expressions at the maternofetal interface. In vitro experiment also showed that rAPN treatment enhanced the FoxP3 mRNA and protein expression and decreased the RORγt expression in splenic lymphocytes of abortion-prone mice. Blocking the different signal transduction pathways downstream of APN, p38MAPK inhibitor (SB203580) and STAT5 inhibitor (Pimozide) could abrogate the regulatory effect of rAPN on FoxP3 and RORγt expression, while STAT3 inhibitor (Stattic) and AMPK inhibitor (p5499) did not exert any influence. Thus, the current results demonstrated that rAPN therapy improves pregnancy outcome in a murine model of abortion by expanding the Treg cell population and function and decreasing the Th17 cell population and function via a p38MAPK-STAT5 pathway.

Systemic adiponectin treatment reverses polycystic ovary syndrome-like features in an animal model

The present study examined the efficacy of adiponectin for regulating the reproductive, metabolic and fertility status of mice with polycystic ovary syndrome (PCOS). PCOS was induced in prepubertal (21- to 22-day-old) mice using dehydroepiandrosterone (6mg 100g-1day-1 for 25days), after which mice were administered either a low or high dose of adiponectin (5 or 15µgmL-1, s.c., respectively). PCOS mice exhibited typical features, including the presence of numerous cystic follicles, increased circulating androgens, increased body mass, altered steroidogenesis, decreased insulin receptor expression and increased serum triglycerides, serum glucose, Toll-like receptor (TLR)-4 (a marker of inflammation) and vascular endothelial growth factor (VEGF; a marker of angiogenesis). These parameters were significantly correlated with a reduction in adiponectin in PCOS mice compared with vehicle-treated control mice. Exogenous adiponectin treatment of PCOS mice restored body mass and circulating androgen, triglyceride and glucose levels. Adiponectin also restored ovarian expression of steroidogenic markers (LH receptors, steroidogenic acute regulatory protein and 3β-hydroxysteroid dehydrogenase), insulin receptor, TLR-4 and VEGF levels in control mice. Adiponectin restored ovulation in PCOS mice, as indicated by the presence of a corpus luteum and attainment of pregnancy. These findings suggest that adiponectin effectively facilitates fertility in anovulatory PCOS. We hypothesise that systemic adiponectin treatment may be a promising therapeutic strategy for the management of PCOS.

Fetal programming by androgen excess in rats affects ovarian fuel sensors and steroidogenesis

Fetal programming by androgen excess is hypothesized as one of the main factors contributing to the development of polycystic ovary syndrome (PCOS). PCOS is more than a reproductive disorder, as women with PCOS also show metabolic and other endocrine alterations. Since both ovarian and reproductive functions depend on energy balance, the alterations in metabolism may be related to reproductive alterations. The present study aimed to evaluate the effect of androgen excess during prenatal life on ovarian fuel sensors and its consequences on steroidogenesis. To this end, pregnant rats were hyperandrogenized with testosterone and the following parameters were evaluated in their female offspring: follicular development, PPARG levels, adipokines (including leptin, adiponectin, and chemerin as ovarian fuel sensors), serum gonadotropins (LH and FSH), the mRNA of their ovarian receptors, and the expression of steroidogenic mediators. At 60 days of age, the prenatally hyperandrogenized (PH) female offspring displayed both an irregular ovulatory phenotype and an anovulatory phenotype with altered follicular development and the presence of cysts. Both PH groups showed altered levels of both proteins and mRNA of PPARG and a different expression pattern of the adipokines studied. Although serum gonadotropins were not impaired, there were alterations in the mRNA levels of their ovarian receptors. The steroidogenic mediators Star, Cyp11a1, Cyp17a1, and Cyp19a1 were altered differently in each of the PH groups. We concluded that androgen excess during prenatal life leads to developmental programming effects that affect ovarian fuel sensors and steroidogenesis in a phenotype-specific way.

Role of adiponectin in ovarian follicular development and ovarian reserve

Adiponectin levels are associated with anti-Müllerian hormone (AMH) and kisspeptin levels in non-ovarian tissues. The objective of the present study was to investigate the association between adiponectin and the genes important for ovarian follicular development and ovarian reserve, specifically AMH and kisspeptin, and their corresponding receptors. In the first experiment, the mRNA levels of anti-Müllerian hormone (amh) and its receptor (Amhr2), as well as those of kisspeptin (Kiss1) and its receptor (Kiss1r), were quantified by reverse transcription-polymerase chain reaction analysis in the ovaries of two groups of mice [adiponectin-knockout (KO) vs. control] that underwent oophorectomy. The second experiment measured follicular phase serum AMH and follicular fluid adiponectin levels in 25 women who underwent controlled ovarian hyperstimulation for in vitro fertilization. Compared with the control mice, adiponectin-KO mice had 6.5 times lower Kiss1 mRNA levels (P=0.009) and a tendency for lower ovarian Kiss1r mRNA expression levels (P=0.06). However, adiponectin-KO mice had significantly higher Amhr2 mRNA levels (P=0.01). In all women participants, there was a positive correlation between serum AMH and follicular fluid adiponectin concentrations (r=0.54, P=0.006). The findings of the present study indicate that adiponectin may play a role in ovarian physiology through its impact on genes crucial for ovarian follicular development and ovarian reserve, such as kisspeptin and AMH. Understanding the role of adiponectin in ovarian function may improve our knowledge of the pathophysiology underlying ovulatory dysfunction in obese women, who usually have low adiponectin levels, and overcome reproductive barriers.

Liraglutide modulates adipokine expression during adipogenesis, ameliorating obesity, and polycystic ovary syndrome in mice

PURPOSE

The incidence of obesity is increasing among all age groups throughout the world and it is highly associated with numerous other metabolic disorders, such as insulin resistance, polycystic ovarian syndrome (PCOS) etc. METHODS AND RESULTS: Using in vitro and in vivo approach, this study investigated the adipokine profile after liraglutide on differentiated murine 3T3-L1 pre-adipocytes. Effect of liraglutide on DHEA-induced PCOS mice were investigated. This study showed Liraglutide treatment resulted in up-regulation of adiponectin and IL-6 along with down-regulation of ICAM 1 in differentiated 3T3-L1 cells. Liraglutide in absence of other differentiating factors, significantly increased glucose, lipid uptake and PPARγ, C/EBPα expression in the adipocytes suggesting its ability to solely promote pre-adipocyte differentiation into mature adipocyte. Liraglutide treatment showed increased adiponectin expression and decreased number of cystic follicles, body weight, circulating glucose, triglyceride and testosterone levels in comparison to the PCOS induced mice.

CONCLUSION

This study suggests that adiponectin may act as a link between metabolic disorders and PCOS and that liraglutide might be a promising therapeutic agent for the treatment of PCOS in addition to obesity and insulin resistance.

Evening Primrose Oil Ameliorates Hyperleptinemia and Reproductive Hormone Disturbances in Obese Female Rats: Impact on Estrus Cyclicity

Obesity is a public health burden disturbing all body functions and reproductive hormones. As obesity increases among females, there will be a rising challenge to physicians in care from fertility problems. Evening primrose oil (EPR oil) contains essential fatty acids including omega-6 linoleic acid with strong anti-inflammatory activity. Since EPR oil has utility in alleviating dysmenorrhea, this study aimed to ascertain its modulatory effect on systemic inflammation, reproductive hormones and estrus cycle irregularity in female obese rats. Thirty-two female rats were distributed to 4 groups: (i) normal, (ii) dietary obese-control female rats, and (iii and iv) dietary obese female rats treated with EPR oil (5 or 10 g/kg). Rats were examined for estrus regularity by taking vaginal smears daily during the last 2 weeks of the experiment. Serum level of insulin, leptin, adiponectin, and inflammatory cytokines was measured. In addition, serum lipid profile, and liver enzyme activities were estimated. Adipose tissues were taken for histopathologic examination as well as determination of gene expression for leptin, leptin receptors, adiponectin, and visfatin. Obese rats exhibited significant weight gain (90.69 ± 8.9), irregular prolonged estrus cycles (83.33%), increased serum levels of insulin, leptin, prolactin and testosterone and decreased gonadotropin levels. EPR oil exhibited a curative effect on obesity-related irregularity in estrus cycle and ovarian pathology. The underlying molecular mechanism may be related to reduction of systemic inflammation, alleviating insulin resistance and modulation of adipokine expression. EPR oil may be considered as a promising therapeutic intervention against obesity-related female hormonal disturbances and estrus irregularity.

The preliminary association study of ADIPOQ, RBP4, and BCMO1 variants with polycystic ovary syndrome and with biochemical characteristics in a cohort of Polish women

PURPOSE

We aimed to elucidate the frequency of the SNPs in the ADIPOQ, RBP4 and BCMO1genes in a population of Caucasian Polish women with polycystic ovary syndrome (PCOS), and to evaluate the possible associations between these variants and the susceptibility to PCOS. Additionally, the relationship of these polymorphisms to a clinical phenotype of this syndrome, and the concentrations of adipokines, were determined.

MATERIALS/METHODS

Clinical and biochemical profiles, DNA isolation and genotyping, and adipokine assays were performed in 294 PCOS women and 78 controls.

RESULTS

In a cohort of Polish women, for the genotype distribution and allele frequencies (minor allele frequency - MAF) proved that only the SNP rs1501299 in the gene ADIPOQ (P = 0.0010, OR = 0.41, 95% C.I.:0.24-0.70) and rs7501331 in the gene BCMO1 (P = 0.0106, OR = 0.24, 95% C.I.:0.21-0.71), are significantly associated (the latter marginally significant) with the decrease of the risk of the disease. Also for this SNPs there were significant differences in the genotypic frequencies in the study population. There was a link between rs12934922 of BCMO1 gen and serum concentration of RBP4 (P = 0.034) and adiponectin (P = 0.038) in the study group but not in the control group. The elevated mean serum concentration of cholesterol (P = 0.020) and LDL cholesterol (P = 0.005) was observed for GG rs1501299 genotype and triglycerides (P = 0.028) for TT rs2241766 genotype.

CONCLUSIONS

The results of the present study revealed that the genes variants RBP4 is not associated with PCO. It seems that rs1501299 of ADIPOQ gene influences the occurrence of PCO and lipids profile in those patients.

Adipose tissue and reproductive health

The understanding of adipose tissue role has evolved from that of a depot energy storage organ to a dynamic endocrine organ. While genetics, sexual phenotype and sex steroids can impact the mass and distribution of adipose tissue, there is a counter-influence of white adipocytes on reproduction. This primarily occurs via the secretion of adipokines, the most studied of which- leptin and adiponectin- are highlighted in this article. Leptin, the "satiety hormone" primarily acts on the hypothalamus via pro-opiomelanocortin (POMC), neuropeptide Y (NPY), and agouti-related peptide (AgRP) neurons to translate acute changes in nutrition and energy expenditure, as well as chronic adipose accumulation into changes in appetite and potentially mediate insulin resistance via shared pathway and notably impacting reproductive health via influence on GnRH secreting neurons. Meanwhile, adiponectin is notable for its action in mediating insulin sensitivity, with receptors found at every level of the reproductive axis. Both have been examined in the context of physiologic and pathologic reproductive conditions. Leptin has been shown to influence puberty, pregnancy, hypothalamic amenorrhea, and lipodystrophy, and with a potential therapeutic role for both metabolic and reproductive health. Adiponectin mediates the relative state of insulin resistance in pregnancy, and has been implicated in conditions such as polycystic ovary syndrome and reproductive malignancies. There are numerous other adipokines, including resistin, visfatin, chemerin and retinol binding protein-4, which may also play roles in reproductive health and disease states. The continued examination of these and other adipokines in both normal reproduction and reproductive pathologies represents an important avenue for continued study. Here, we seek to provide a broad, yet comprehensive overview of many facets of these relationships and highlight areas of consideration for clinicians and future study.

Obesity as disruptor of the female fertility

Both obesity and overweight are increasing worldwide and have detrimental influences on several human body functions including the reproductive health. In particular, obese women undergo perturbations of the 'hypothalamic pituitary ovarian axis', and frequently suffer of menstrual dysfunction leading to anovulation and infertility. Besides the hormone disorders and subfertility that are common in the polycystic ovary syndrome (PCOS), in obesity the adipocytes act as endocrine organ. The adipose tissue indeed, releases a number of bioactive molecules, namely adipokines, that variably interact with multiple molecular pathways of insulin resistance, inflammation, hypertension, cardiovascular risk, coagulation, and oocyte differentiation and maturation. Moreover, endometrial implantation and other reproductive functions are affected in obese women with complications including delayed conceptions, increased miscarriage rate, reduced outcomes in assisted conception treatments.On the contrary, weight loss programs through lifestyle modification in obese women, have been proven to restore menstrual cyclicity and ovulation and improve the likelihood of conception.

Can serum vaspin levels predict clomiphene resistance in infertile women with PCOS?

OBJECTIVE

To determine whether serum vaspin levels can predict the success of ovulation induction and clomiphene resistance in anovulatory women with PCOS.

STUDY DESIGN

We designed a prospective case control study. The study population (n=49) was composed of infertile women with PCOS who underwent ovulation induction with clomiphene citrate. Patients were divided into two groups based on their treatment response. Group I consisted of patients with failed ovulation induction, and group II consisted of patients with successful ovulation induction. The study group characteristics, including age, BMI, waist-to-hip ratio, parity, hormone profiles, fasting insulin and glucose levels, HOMA-IR, triglycerides, and cholesterol and serum vaspin levels, were compared between the study groups.

RESULT(S)

There were 29 patients in Group I with failed ovulation induction (59.2%), and Group II consisted of 20 patients with successful ovulation induction (40.8%). No differences in characteristics were found. However, serum vaspin levels were significantly lower in responders achieving ovulation (p=0.001; p<0.01). At a vaspin level of 3.74, the sensitivity, specificity, positive predictive and negative predictive values were 90%, 72.4%, 69.2% and 91.3%, respectively. The odds ratio was determined to be 14.87 (95% CI: 3.41-64.88) as the cut-off point. No significant correlation was found in serum vaspin measurements between pregnant and non-pregnant patients who had achieved successful ovulation induction (p=0.5).

CONCLUSION(S)

Serum vaspin level may be a useful marker for the prediction of ovulation induction success in treatment with clomiphene citrate, and increased vaspin levels (≥3.74ng/mL) are correlated with clomiphene resistance in patients with PCOS according to our study results.

Direct action of adiponectin ameliorates increased androgen synthesis and reduces insulin receptor expression in the polycystic ovary

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder of reproductive age females, leading to infertility. Despite extensive research, the exact pathophysiology and treatment are lacking. The aim of the current study was to evaluate the direct role of adiponectin either alone or together with luteinizing hormone (LH) on sex hormone synthesis and changes in insulin receptor (IR) in the ovary of dehydroepiandrosterone (DHEA)-treated PCOS-mice. Immunohistochemical study showed decreased expression of adiponectin receptor (AdipoR1) in PCOS-ovary which correlated with increased synthesis of androgen and decreased expression of IR. The treatment with adiponectin with or without LH to PCOS-ovary in vitro caused significant decline in androgen synthesis and increase in IR. This study showed the direct role of adiponectin in ameliorating hyperandrogenism and reducing IR in the ovary of PCOS-mice. Thus adiponectin treatment may be a novel therapeutic strategy for combating PCOS.

The physiology of functional hypothalamic amenorrhea associated with energy deficiency in exercising women and in women with anorexia nervosa

An energy deficiency is the result of inadequate energy intake relative to high energy expenditure. Often observed with the development of an energy deficiency is a high drive for thinness, dietary restraint, and weight and shape concerns in association with eating behaviors. At a basic physiologic level, a chronic energy deficiency promotes compensatory mechanisms to conserve fuel for vital physiologic function. Alterations have been documented in resting energy expenditure (REE) and metabolic hormones. Observed metabolic alterations include nutritionally acquired growth hormone resistance and reduced insulin-like growth factor-1 (IGF-1) concentrations; hypercortisolemia; increased ghrelin, peptide YY, and adiponectin; and decreased leptin, triiodothyronine, and kisspeptin. The cumulative effect of the energetic and metabolic alterations is a suppression of the hypothalamic-pituitary-ovarian axis. Gonadotropin releasing hormone secretion is decreased with consequent suppression of luteinizing hormone and follicle stimulating hormone release. Alterations in hypothalamic-pituitary secretion alters the production of estrogen and progesterone resulting in subclinical or clinical menstrual dysfunction.

Increased trabecular bone and improved biomechanics in an osteocalcin-null rat model created by CRISPR/Cas9 technology

Osteocalcin, also known as bone γ-carboxyglutamate protein (Bglap), is expressed by osteoblasts and is commonly used as a clinical marker of bone turnover. A mouse model of osteocalcin deficiency has implicated osteocalcin as a mediator of changes to the skeleton, endocrine system, reproductive organs and central nervous system. However, differences between mouse and human osteocalcin at both the genome and protein levels have challenged the validity of extrapolating findings from the osteocalcin-deficient mouse model to human disease. The rat osteocalcin (Bglap) gene locus shares greater synteny with that of humans. To further examine the role of osteocalcin in disease, we created a rat model with complete loss of osteocalcin using the CRISPR/Cas9 system. Rat osteocalcin was modified by injection of CRISPR/Cas9 mRNA into the pronuclei of fertilized single cell Sprague-Dawley embryos, and animals were bred to homozygosity and compound heterozygosity for the mutant alleles. Dual-energy X-ray absorptiometry (DXA), glucose tolerance testing (GTT), insulin tolerance testing (ITT), microcomputed tomography (µCT), and a three-point break biomechanical assay were performed on the excised femurs at 5 months of age. Complete loss of osteocalcin resulted in bones with significantly increased trabecular thickness, density and volume. Cortical bone volume and density were not increased in null animals. The bones had improved functional quality as evidenced by an increase in failure load during the biomechanical stress assay. Differences in glucose homeostasis were observed between groups, but there were no differences in body weight or composition. This rat model of complete loss of osteocalcin provides a platform for further understanding the role of osteocalcin in disease, and it is a novel model of increased bone formation with potential utility in osteoporosis and osteoarthritis research.

Summary: A complete null of osteocalcin, generated by the CRISPR/Cas9 system, results in an increase in trabecular bone, increased bone strength and altered glucose homeostasis in Sprague-Dawley rats.

Aberrant expression of angiopoietin-like proteins 1 and 2 in cumulus cells is potentially associated with impaired oocyte developmental competence in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder associated with obesity, insulin resistance, hyperandrogenism, alterations in ovarian angiogenesis and impaired oocyte competence. Emerging evidence demonstrates that angiopoietin-like protein 1 (ANGPTL1) and angiopoietin-like protein 2 (ANGPTL2) have an important influence on angiogenesis, androgen biosynthesis, insulin resistance and adipocytes function. In this study, we set out to determine the potential relationship between ANGPTL1, ANGPTL2 and oocyte competence in PCOS through analyzing the expression levels and dynamic pattern of the two genes in cumulus cells (CCs) during different phases of nuclear maturation of PCOS patients and control groups undergoing controlled ovarian hyperstimulation (COH) for in vitro fertilization and embryo transfer. We found that the relative abundance of ANGPTL1 and ANGPTL2 transcripts in CCs from patients with PCOS showed dynamic changes during oocyte maturation. Specifically, their expressions were increased significantly at the Metaphase II stage. In summary, the present novel evidence indicates that the expression patterns of ANGPTL1 and ANGPTL2 mRNAs are disordered during oocyte maturation in PCOS, which were potentially related to aberrant oocyte quality and developmental potency, at least in part, via pathological angiogenesis and metabolism.

Effects of Adiponectin Including Reduction of Androstenedione Secretion and Ovarian Oxidative Stress Parameters In Vivo

Adiponectin is the most abundantly produced human adipokine with anti-inflammatory, anti-oxidative, and insulin-sensitizing properties. Evidence from in vitro studies has indicated that adiponectin has a potential role in reproduction because it reduces the production of androstenedione in bovine theca cells in vitro. However, this effect on androgen production has not yet been observed in vivo. The current study evaluated the effect of adiponectin on androstenedione secretion and oxidative stress parameters in a rodent model. Seven-week-old female Balb/c mice (n = 33), previously treated with equine gonadotropin chorionic, were assigned to one of four different treatments: Group 1, control (phosphate-buffered saline); Group 2, adiponectin 0.1 μg/mL; Group 3, adiponectin 1.0 μg/mL; Group 4, adiponectin 5.0 μg/mL. After 24 h, all animals were euthanized and androstenedione levels were measured in the serum while oxidative stress markers were quantified in whole ovary tissue. Female mice treated with adiponectin exhibited a significant reduction (about 60%) in serum androstenedione levels in comparison to controls. Androstenedione levels decreased from 0.78 ± 0.4 ng/mL (mean ± SD) in controls to 0.28 ± 0.06 ng/mL after adiponectin (5 μg/mL) treatment (P = 0.01). This change in androgen secretion after 24 hours of treatment was associated with a significant reduction in the expression of CYP11A1 and STAR (but not CYP17A1). In addition, ovarian AOPP product levels, a direct product of protein oxidation, decreased significantly in adiponectin-treated mice (5 μg/mL); AOPP (mean ± SD) decreased to 4.3 ± 2.1 μmol/L in comparison with that of the controls (11.5 ± 1.7 μmol/L; P = 0.0003). Our results demonstrated for the first time that acute treatment with adiponectin reduced the levels of a direct oxidative stress marker in the ovary as well as decreased androstenedione serum levels in vivo after 24 h.

CpG Oligodeoxynucleotides Downregulate Placental Adiponectin and Increase Embryo Loss in Non-Obese Diabetic Mice

PROBLEM

CpG oligodeoxynucleotides (ODNs) can induce immunological changes in non-obese diabetic (NOD) mice and increase embryo loss, but little is known about the mechanism. This study aimed to determine the role of adiponectin in CpG ODN-induced pregnancy failure.

METHOD OF STUDY

Oligodeoxynucleotide 1826 was intraperitoneally injected to NOD mice, and ODN 2216, ODN 2006, and ODN 2395 were used to stimulate human trophoblast cell lines to investigate adiponectin expression patterns and its possible effects on trophoblast function.

RESULTS

CpG ODNs downregulated adiponectin via the cJun N-terminal kinase signaling pathway and led to increased embryo loss (from 6.9 to 33.3%). ODN 2006 impaired human trophoblast cell migration, which was successfully rescued by adiponectin treatment.

CONCLUSION

CpG ODNs decreased placental adiponectin expression in NOD mice and impaired human trophoblast function and was associated with increased embryo loss. Adiponectin may therefore play an important protective role in the prevention of bacteria-induced pregnancy failure.

The Deep Correlation between Energy Metabolism and Reproduction: A View on the Effects of Nutrition for Women Fertility

In female mammals, mechanisms have been developed, throughout evolution, to integrate environmental, nutritional and hormonal cues in order to guarantee reproduction in favorable energetic conditions and to inhibit it in case of food scarcity. This metabolic strategy could be an advantage in nutritionally poor environments, but nowadays is affecting women's health. The unlimited availability of nutrients, in association with reduced energy expenditure, leads to alterations in many metabolic pathways and to impairments in the finely tuned inter-relation between energy metabolism and reproduction, thereby affecting female fertility. Many energetic states could influence female reproductive health being under- and over-weight, obesity and strenuous physical activity are all conditions that alter the profiles of specific hormones, such as insulin and adipokines, thus impairing women fertility. Furthermore, specific classes of nutrients might affect female fertility by acting on particular signaling pathways. Dietary fatty acids, carbohydrates, proteins and food-associated components (such as endocrine disruptors) have per se physiological activities and their unbalanced intake, both in quantitative and qualitative terms, might impair metabolic homeostasis and fertility in premenopausal women. Even though we are far from identifying a "fertility diet", lifestyle and dietary interventions might represent a promising and invaluable strategy to manage infertility in premenopausal women.

Downregulation of adiponectin system in granulosa cells and low levels of HMW adiponectin in PCOS

PURPOSE

The purpose of the study was to investigate changes in adiponectin system expression in granulosa cells (GCs) and high molecular weight adiponectin levels in serum and follicular fluid (FF) of 40 women with polycystic ovary syndrome (PCOS) compared to those in 40 women with normal ovary function.

METHODS

Adiponectin (Adipo), adiponectin receptor 1 (AdipoR1), and adiponectin receptor 2 (AdipoR2) messenger RNA (mRNA) expression levels were measured using quantitative real-time polymerase chain reaction (qRT-PCR). High molecular weight (HMW) adiponectin protein concentration was evaluated by ELISA method. Data were analyzed using Student's t test and one-way ANOVA in SPSS 21 software. At oocyte retrieval, FF was aspirated and GCs were obtained from a pooled collection of FF per each patient.

RESULTS

PCR results showed expression of adiponectin, AdipoR1, AdipoR2, follicle-stimulating hormone receptor (FSHR), and luteinizing hormone receptor (LHR) in GCs. After controlling body mass index (BMI) values, qRT-PCR demonstrated a decreased expression of adiponectin system in GCs of PCOS patients compared to those in controls (p = 0.001). There was a strong positive correlation among AdipoR1 and AdipoR2 expression and also among FSH and LH receptor expression. (Both r = 0.8, p = 0.001). There were low levels of high molecular weight adiponectin in the serum of PCOS patients with controlled ovarian hyperstimulation (30.19 ± 4.3 ng/ml) compared to the controls (48.47 ± 5.9 ng/ml) and in the FF of PCOS patients with controlled ovarian hyperstimulation (7.86 ± 1.44 ng/ml) compared to the controls (14.22 ± 2.01 ng/ml; p = 0.02).

CONCLUSIONS

Lower expression of adiponectin and its receptors in GCs might be an important manifestation in gonadotropin-stimulated PCOS patients which could influence the physiologic adiponectin roles such as interaction with insulin and LH in induction of GC gene expression.

Direct effects of leptin and adiponectin on peripheral reproductive tissues: a critical review

Obesity is a risk factor for infertility and adverse reproductive outcomes. Adipose tissue is an important endocrine gland that secretes a host of endocrine factors, called adipokines, which modulate diverse physiologic processes including appetite, metabolism, cardiovascular function, immunity and reproduction. Altered adipokine expression in obese individuals has been implicated in the pathogenesis of a host of health disorders including diabetes and cardiovascular disease. It remains unclear whether adipokines play a significant role in the pathogenesis of adverse reproductive outcomes in obese individuals and, if so, whether the adipokines are acting directly or indirectly on the peripheral reproductive tissues. Many groups have demonstrated that receptors for the adipokines leptin and adiponectin are expressed in peripheral reproductive tissues and that these adipokines are likely, therefore, to exert direct effects on these tissues. Many groups have tested for direct effects of leptin and adiponectin on reproductive tissues including the testis, ovary, uterus, placenta and egg/embryo. The hypothesis that decreased fertility potential or adverse reproductive outcomes may result, at least in part, from defects in adipokine signaling within reproductive tissues has also been tested. Here, we present a critical analysis of published studies with respect to two adipokines, leptin and adiponectin, for which significant data have been generated. Our evaluation reveals significant inconsistencies and methodological limitations regarding the direct effects of these adipokines on peripheral reproductive tissues. We also observe a pervasive failure to account for in vivo data that challenge observations made in vitro. Overall, while leptin and adiponectin may directly modulate peripheral reproductive tissues, existing data suggest that these effects are minor and non-essential to human or mouse reproductive function. Current evidence suggests that direct effects of leptin or adiponectin on peripheral reproductive tissues are unlikely to factor significantly in the adverse reproductive outcomes observed in obese individuals.

In prostate cancer, low adiponectin levels are not associated with insulin resistance

PURPOSE

Adiponectin, an adipose tissue-derived hormone with insulin-sensitizing effect, has been inversely associated with several hormonally dependent malignancies. Prostate cancer is associated with low levels of adiponectin, which have been proposed as an independent risk factor for this malignancy. Aim of this study was to examine whether hypoadiponectinaemia in prostate is associated with insulin resistance.

EXPERIMENTAL DESIGN

Plasma samples and covariate data in the context of a case-control study of 300 Greek men were evaluated including 75 patients with prostate cancer, 75 patients with benign prostatic hyperplasia (BPH) and 150 age-matched healthy controls.

RESULTS

Patients with prostate cancer had significantly lower plasma adiponectin levels compared with the other two groups, that is BPH patients and healthy controls (7.4 ± 5 ng/mL vs. 11.5 ± 6.4 ng/mL and 12.8 ± 8 ng/mL, respectively). On the other hand, no statistically significant differences were found between patients with prostate cancer and the other two groups for both HOMA-IR and QUICKI (P-value = 0.551). As expected, in all three groups, the levels of adiponectin correlated negatively with HOMA-IR (rho = -0.214, P-value = 0.006), QUICKI (rho = 0.214, P-value = 0.006) and insulin levels (rho = 0.942, P-value < 0.001).

CONCLUSION

In spite of what would have been expected from the relevant literature, our data suggest that the hypoadiponectinaemia in prostatic cancer does not appear to be associated with insulin resistance.

Adiposity Alters Genes Important in Inflammation and Cell Cycle Division in Human Cumulus Granulosa Cell

OBJECTIVE

To determine whether obesity alters genes important in cellular growth and inflammation in human cumulus granulosa cells (GCs).

METHODS

Eight reproductive-aged women who underwent controlled ovarian hyperstimulation followed by oocyte retrieval for in vitro fertilization were enrolled. Cumulus GC RNA was extracted and processed for microarray analysis on Affymetrix Human Genome U133 Plus 2.0 chips. Gene expression data were validated on GCs from additional biologically similar samples using quantitative real-time polymerase chain reaction (RT-PCR). Comparison in gene expression was made between women with body mass index (BMI) <25 kg/m(2) (group 1; n = 4) and those with BMI ≥25 kg/m(2) (group 2; n = 4).

RESULTS

Groups 1 and 2 had significantly different BMI (21.4 ± 1.4 vs 30.4 ± 2.7 kg/m(2), respectively; P = .02) but did not differ in age (30.5 ± 1.7 vs 32.7 ± 0.3 years, respectively; P = .3). Comparative analysis of gene expression profiles by supervised clustering between group 1 versus group 2 resulted in the selection of 7 differentially expressed genes: fibroblast growth factor 12 (FGF-12), protein phosphatase 1-like (PPM1L), zinc finger protein multitype 2 (ZFPM2), forkhead box M1 (FOXM1), cell division cycle 20 (CDC20), interleukin 1 receptor-like 1 (IL1RL1), and growth arrest-specific protein 7 (GAS7). FOXM1, CDC20, and GAS7 were downregulated while FGF-12 and PPM1L were upregulated in group 2 when compared to group 1. Validation with RT-PCR confirmed the microarray data except for ZFPM2 and IL1RL. As BMI increased, expression of FOXM1 significantly decreased (r = -.60, P = .048).

CONCLUSIONS

Adiposity is associated with changes in the expression of genes important in cellular growth, cell cycle progression, and inflammation. The upregulation of the metabolic regulator gene PPM1L suggests that adiposity induces an abnormal metabolic follicular environment, potentially altering folliculogenesis and oocyte quality.

Association of fetuin A, adiponectin, interleukin 10 and total antioxidant capacity with IVF outcomes

BACKGROUND

Possible roles of anti-inflammatory factors as well as total antioxidative capacity in reproductive processes of women undergoing in vitro fertilization (IVF) are still being investigated and the contributions by some of them remain controversial.

OBJECTIVE

The aim of this study is to investigate the relationship between anti-inflammatory parameters and total antioxidative capacity (TAC) of the body during IVF. In this respect, adiponectin, interleukin-10 (IL-10), interleukin-1 receptor antagonist (IL-1RA), fetuin A and TAC analyses have been performed.

MATERIALS AND METHODS

In this prospective, non-randomized, controlled clinical study, sera obtained from 26 fertile (Group-1), and 26 infertile women before (Group-2) and after (Group-3) IVF treatment were analyzed. IL-1RA, IL-10, fetuin A, adiponectin and insulin were determined by ELISA. TAC was determined spectrophotometrically. Mann-Whitney U test, paired sample t-test, Wilcoxon signed-rank test as well as Pearson correlation analysis by SPSS were performed for statistical analysis.

RESULTS

Clinical pregnancy and live birth rates were determined as 30.8% and 23.1%, respectively, in pregnant group. For the pregnant, significant indirect correlations were detected between fetuin A and adiponectin (r=-0.843; p=0.035) as well as IL-10 (r=-0.846; p=0.034) in Group 2. The correlation between adiponectin and IL-10 doubled in pregnant compared to non-pregnant (r=0.929; p=0.007 vs. r=0.478; p=0.033). The correlations between fetuin A and TAC in pregnant were noted both in Group 2 (r=0.892; p=0.017) and Group 3 (r=0.875; p=0.022). No correlation of fetuin A with these parameters was detected in non-pregnant group.

CONCLUSION

Fetuin A, TAC, IL-10, adiponectin and their associations may be important from their predictive values for IVF success point of view. Parameters with anti-inflammatory or antioxidant property appear to improve pregnancy in women undergoing IVF.

Adipokines and the female reproductive tract

It is well known that adipose tissue can influence puberty, sexual maturation, and fertility in different species. Adipose tissue secretes molecules called adipokines which most likely have an endocrine effect on reproductive function. It has been revealed over the last few years that adipokines are functionally implicated at all levels of the reproductive axis including the gonad and hypothalamic-pituitary axis. Many studies have shown the presence and the role of the adipokines and their receptors in the female reproductive tract of different species. These adipokines regulate ovarian steroidogenesis, oocyte maturation, and embryo development. They are also present in the uterus and placenta where they could create a favorable environment for embryonic implantation and play a key role in maternal-fetal metabolism communication and gestation. Reproductive functions are strongly dependent on energy balance, and thereby metabolic abnormalities can lead to the development of some pathophysiologies such as polycystic ovary syndrome (PCOS). Adipokines could be a link between reproduction and energy metabolism and could partly explain some infertility related to obesity or PCOS.

Management of reproduction and pregnancy complications in maternal obesity: which role for dietary polyphenols?

Obesity is a global and dramatic public health problem; maternal obesity represents one of the main risk factors of infertility and pregnancy complications as it is associated with adverse maternal and offspring outcomes. In the last few years, adipose tissue dysfunction associated with altered adipocytokine secretion has been suggested to play a critical role in all the phases of reproductive process. Obesity is a nutrition-related disorder. In this regard, dietary intervention strategies, such as high intake of fruit and vegetables, have shown significant effects in both preserving health and counteracting obesity-associated diseases. Evidence has been provided that polyphenols, important constituents of plant-derived food, can influence developmental program of oocyte and embryo, as well as pregnancy progression by modulating several cellular pathways. This review will examine the controversial results so far obtained on adipocytokine involvement in fertility impairment and pregnancy complications. Furthermore, the different effects exerted by polyphenols on oocyte, embryo, and pregnancy development will be also taken in account.

Salivary adiponectin levels are associated with training intensity but not with bone mass or reproductive function in elite Rhythmic Gymnasts

Elite Rhythmic Gymnasts (RGs) constitute a unique metabolic model and they are prone to developing Anorexia Athletica. The aim of the present study was to evaluate the effect of training intensity on salivary adiponectin levels and assess a possible role of salivary adiponectin levels as a predictive factor of reproductive dysfunction and bone mass acquisition in elite RGs. The study included 80 elite female RGs participating in the World Rhythmic Gymnastics Championship tournament held in Montpellier, France on September 2011. Anthropometric values were assessed, training data and menstrual pattern were recorded, bone mass was measured with Broadband ultrasound attenuation (dB/Mhz) and baseline salivary adiponectin levels were determined. The athletes were classified as intensely and very intensely trained, considering the mean training intensity (40.84h/week). Moreover, considering their reproductive status, they were divided into RG's with normal menstruation, primary amenorrhea and oligomenorrhea. All comparisons were adjusted to age, BMI and body fat percentage differences. Very intensely trained RGs showed higher salivary adiponectin levels (p=0.05). Moreover, salivary adiponectin levels showed significant correlation with training intensity (r=0.409, p=0.003). On the other hand, no association of salivary adiponectin levels was documented with either reproductive function or bone mass acquisition. The results of the present study suggest that, in elite RGs, salivary adiponectin levels are associated with the intensity of training, possibly reflecting the deterioration of energy balance rather than the training stress. On the other hand, a predictive role of salivary adiponectin levels in reproductive dysfunction or bone mass acquisition could not be supported.

Obesity in the ageing man

As the population is ageing globally, both ageing and obesity are recognized as major public health challenges. The aim of this narrative review is to present and discuss the current evidence on the changes in body composition, energy balance and endocrine environment that occur in the ageing man. Obesity in the ageing man is related to changes in both body weight and composition due to alterations in energy intake and total energy expenditure. In addition, somatopenia (decreased GH secretion), late-onset hypogonadism (LOH), changes in thyroid and adrenal function, as well as changes in appetite-related peptides (leptin, ghrelin) and, most importantly, insulin action are related to obesity, abnormal energy balance, redistribution of the adipose tissue and sarcopenia (decreased muscle mass). A better understanding of the complex relationship of ageing-related endocrine changes and obesity could lead to more effective interventions for elderly men.