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

Relationship between adipokines and androgens in children and young adults with congenital adrenal hyperplasia

Introduction

Children and young adults with congenital adrenal hyperplasia (CAH) are at increased risk of obesity and insulin resistance. There is evidence that children with CAH have increased visceral adiposity, which has been linked to metabolic syndrome and cardiovascular disease (CVD). The adipokine adiponectin has been shown to correlate with reduced metabolic risk, whereas the adipokines visfatin and leptin have been linked to visceral fat and adipocyte inflammation and can serve as biomarkers of increased metabolic risk. Few studies to date have characterized adipokine levels in children and young adults with congenital adrenal hyperplasia. We sought to investigate the relationship between adiponectin, leptin and visfatin levels to metabolic risk factors and androgen levels in children and young adults with CAH.

Methods

Fasting blood was obtained for visfatin, leptin, adiponectin, glucose, insulin, CRP, lipid panel, total cholesterol (TC), triglycerides (TG) and HbA1c, as well as standard laboratory tests to assess adrenal control, from children with CAH due to 21-hydroxylase deficiency. HOMA-IR was calculated based on fasting glucose and insulin. Anthropomorphic measurements of BMI and waist-to-hip ratio were also obtained.

Results

Adiponectin and androstenedione were inversely correlated (R = -0.57, p =0.016). There was a positive correlation between leptin and BMI percentile (R = 0.63, p <0.001) as well as leptin and HOMA-IR (R = 0.63, p <0.01). Glucocorticoid dose had a positive correlation with HOMA-IR (R=0.56, p = 0.021). Visfatin was inversely correlated with HDL cholesterol (R = -0.54, p = 0.026) and total cholesterol (R = -0.49, p <0.05). Overweight children and young adults had a significantly higher leptin (p = 0.02) and HOMA-IR (p=0.001) than non-overweight children and young adults.

Conclusion

The inverse relationship between adiponectin and androstenedione suggests that better CAH control can reduce the risk of insulin resistance and metabolic syndrome. However, a high glucocorticoid dose appears to increase the risk of insulin resistance, underscoring the delicate balance required when treating CAH.

Metabolic hormones are integral regulators of female reproductive health and function

The female reproductive system is strongly influenced by nutrition and energy balance. It is well known that food restriction or energy depletion can induce suppression of reproductive processes, while overnutrition is associated with reproductive dysfunction. However, the intricate mechanisms through which nutritional inputs and metabolic health are integrated into the coordination of reproduction are still being defined. In this review, we describe evidence for essential contributions by hormones that are responsive to food intake or fuel stores. Key metabolic hormones-including insulin, the incretins (glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1), growth hormone, ghrelin, leptin, and adiponectin-signal throughout the hypothalamic-pituitary-gonadal axis to support or suppress reproduction. We synthesize current knowledge on how these multifaceted hormones interact with the brain, pituitary, and ovaries to regulate functioning of the female reproductive system, incorporating in vitro and in vivo data from animal models and humans. Metabolic hormones are involved in orchestrating reproductive processes in healthy states, but some also play a significant role in the pathophysiology or treatment strategies of female reproductive disorders. Further understanding of the complex interrelationships between metabolic health and female reproductive function has important implications for improving women's health overall.

The effects of AdipoRon on cytochrome P450-related gene expression, acute steroidogenic regulatory protein, and structure of ovary in polycystic ovary syndrome model

PURPOSE

One of the most common causes of infertility in adult women is polycystic ovary syndrome (PCOS) which has been identified with symptoms such as chronic hyperandrogenism, anovulation, and polycystic ovaries. Adiponectin modulates steroidogenesis and the expression of ovulation-related genes. Herein, we assessed the effect of AdipoRon (adiponectin agonist) in the PCOS model mice.

METHODS

The PCOS model was induced with letrozole in the adult female mice and the animals received intraperitoneal injection of AdipoRon (5 mg/kg) for 10 days. Expression of CYP11A, CYP17A, and CYP19A genes, StAR protein, and histomorphology of the ovary were evaluated using real-time RT-PCR, western blotting, and histochemistry methods, respectively.

RESULTS

Although administration of letrozole caused an increase in the expression of CYP11A, CYP17A, and StAR and a decrease in the CYP19A1 expression, injection of AdipoRon reversed these changes. Moreover, AdipoRon treatment resulted in an improvement of folliculogenesis and a reduction of cysts compared to the letrozole-treated mice.

CONCLUSION

It is likely that AdipoRon has protective effects on the PCOS through modulation of cytochrome P450-related genes and steroidogenesis but needs further study to be sure.

Contribution of key elements of nutritional metabolism to the development of cystic ovarian disease in dairy cattle

The alteration of signaling molecules involved in the general metabolism of animals can negatively influence reproduction. In dairy cattle, the development of follicular cysts and the subsequent appearance of ovarian cystic disease (COD) often lead to decreased reproductive efficiency in the herd. The objective of this review is to summarize the contribution of relevant metabolic and nutritional sensors to the development of COD in dairy cows. In particular, we focus on the study of alterations of the insulin signaling pathway, adiponectin, and other sensors and metabolites relevant to ovarian functionality, which may be related to the development of follicular persistence and follicular formation of cysts in dairy cattle. The results of these studies support the hypothesis that systemic factors could alter the local scenario in the follicle, generating an adverse microenvironment for the resumption of ovarian activity and possibly leading to the persistence of follicles and to the development and recurrence of COD.

Seasonal Change in Adiponectin Associated with Ovarian Morphology and Function in Wild Ground Squirrels (Citellus dauricus Brandt)

The goal of this study is to explore the relationship between altered circulating adiponectin concentration, ovarian tissue morphology, ovarian steroidogenesis, and sex hormone production in ovaries of wild ground squirrels. The ovarian mass differed significantly during the breeding and non-breeding seasons, and the circulating estradiol and progesterone concentrations were significantly higher in the breeding season, while the circulating adiponectin level was significantly lower. The expression levels of gonadotropin receptors (FSHR and LHR) and steroidogenic enzymes (StAR, P450scc, P450arom, and 3β-HSD) were significantly higher during the breeding season. Comparing the ovarian transcriptome data of wild ground squirrels between the two periods, we found that some differentially expressed genes were enriched for ovarian steroidogenesis and the adipocytokine signaling pathway, which correlated with our present results. Notably, the MAPK signaling pathway was also enriched and its related genes (Erk1, p38 Mapk, Jnk) were up-regulated by qPCR during the non-breeding season. These findings suggested that adiponectin may be involved in the regulation of seasonal changes in the ovarian function of wild ground squirrels, possibly by acting on the MAPK signaling pathway to regulate sex steroidogenesis in the ovaries.

Adipokinesand Ghrelin Rolein Regulation of Ovarian Function in Obesity

There is a great worldwide trend in the incidence of obesity, which is increasing with each passing year among all populations, including women of reproductive age. Given the impressive list of diseases associated with obesity, as well as the negative inverse correlation of the severity of obesity with fertility, this problem is global not only in the social sphere, but it also becomes demographically significant.

Along with other pathogenetic mechanisms leading to persistent anovulation, an imbalance in adipokine production by adipose tissue can also serve as one of the important links in the development of reproductive dysfunction. Despite apparent interest in this topic, a large number of previously discovered adipokines are still not studied. Among adipokines, the effects of adiponectin and leptin on reproductive function are best known. Alterations in adiponectin and leptin levels can affect hypothalamic-pituitary-gonadal signaling, folliculogenesis, oogenesis and steroidogenesis. In addition, leptin is involved in the initiation of puberty, regulation of the menstrual cycle, and changes the balance between proliferation and apoptosis in ovarian cells. The leading causes of reduced fertility, infertility, and IVF failure in obese patients are mechanisms that promote the formation of chronic anovulation, delay the maturation of oocytes, reduce their quality, and/or lead to changes in endometrial susceptibility. These effects can be caused by an imbalance in the concentrations of leptin and adiponectin (leptin excess and adiponectin deficiency), lead to endometrial dysfunction, disruption of implantation and early embryogenesis. These changes, in turn, can affect just as the likelihood of spontaneous conception, so the effectiveness of assisted reproductive technologies and subsequent gestation.

Thus, the study of potential pathogenetic pathways of fertility regulation in obesity, one of which is the subject of this review, is an important area for further study.

Shared postulations between bipolar disorder and polycystic ovary syndrome pathologies

INTRODUCTION

Women with bipolar disorder (BD) present a high prevalence of polycystic ovary syndrome (PCOS) and other reproductive disorders even before diagnosis or treatment of the disease. Postulations on the potential molecular mechanisms of comorbid PCOS in women with BD remain limited to influence of medications and need further extension.

OBJECTIVES

This review focuses on evidence suggesting that common metabolic and immune disorders may play an important role in the development of BD and PCOS.

RESULTS

The literature covered in this review suggests that metabolic and immune disorders, including the dysfunction of the hypothalamic-pituitary-adrenal axis, chronic inflammatory state, gut microbial alterations, adipokine alterations and circadian rhythm disturbance, are observed in patients with BD and PCOS. Such disorders may be responsible for the increased prevalence of PCOS in the BD population and indicate a susceptibility gene overlap between the two diseases. Current evidence supports postulations of common metabolic and immune disorders as endophenotype in BD as well as in PCOS.

CONCLUSIONS

Metabolic and immune disorders may be responsible for the comorbid PCOS in the BD population. The identification of hallmark metabolic and immune features common to these two diseases will contribute to the clarification of the effect of BD on the reproductive endocrine function and development of symptomatic treatments targeting the biomarkers of the two diseases.

Role of adipokines in the ovarian function: Oogenesis and steroidogenesis

Adipokines are mainly produced by adipose tissue; however, their expression has been reported in other organs including female reproductive tissues. Therefore, adipokines have opened new avenues of research in female fertility. In this regard, studies reported different roles for certain adipokines in ovarian function, although the role of other recently identified adipokines is still controversial. It seems that adipokines are essential for normal ovarian function and their abnormal levels could be associated with ovarian-related disorders. The objective of this study is to review the available information regarding the role of adipokines in ovarian functions including follicular development, oogenesis and steroidogenesis and also their involvement in ovary-related disorders.

Adiponectin modulates steroid hormone secretion, granulosa cell proliferation and apoptosis via binding its receptors during hens' high laying period

Adiponectin is an important adipocytokine and plays the roles in multiple metabolic processes via binding its receptors - AdipoR1 and AdipoR2, which has also been found to participate in the regulation of the reproductive system of animals, in particular by influencing the secretion of ovarian steroid hormones. To further investigate the expression of adiponectin and its receptors in follicles after in vitro incubation, and their role in the steroid synthesis of laying hens’ ovaries, we performed qRT-PCR and ELISA to detect the expressions of AdipoQ, AdipoR1, and AidpoR2, and determined the key genes involved in steroidogenesis and the secretion of estradiol (E2) and progesterone (P4) through the in vitro activation of adiponectin (AipoRon) and overexpression or knockdown of AdipoR1 and AdipoR2. Our results revealed that adiponectin and its receptors wildly exist in follicles and granulosa cells, and AdipoRon (5 and 10 µg/mL) had no effect on granulosa cell proliferation and apoptosis but significantly stimulated the secretion of adiponectin and its receptors in granulosa cells after incubation for 24 h. Furthermore, AdipoRon could significantly stimulate the secretion of P4 and inhibit E2 level compared to those of the control group through modulating the key genes expression of steroidogenesis (CYP19A1, StAR, CYP11A1, FSHR, and LHR). The secretion of E2 was also decreased in granulosa cells by the treatments of overexpression and knockdown of AdipoR1/2, however, there was no difference in terms of the level of P4 and StAR expression between them if there was overexpression or knockdown of AdipoR1/2. In addition, it was shown that the secretion of E2 only exhibits a marked drop if co-processing 10 µg/mL AdipoRon and pGMLV AdipoR2 compared to single treatments. Taken together, the study highlighted the role of adiponectin and its receptors in the regulation of steroid synthesis and secretion in ovarian granulosa cells in laying hens.

Traditional Chinese Medicine formula FTZ protects against polycystic ovary syndrome through modulating adiponectin-mediated fat-ovary crosstalk in mice

ETHNOPHARMACOLOGICAL RELEVANCE

FuFang ZhenZhu TiaoZhi (FTZ) is a hospitalized traditional Chinese medicine herbal formula with documented metabolic benefits. Polycystic ovary syndrome (PCOS) characterized by ovarian dysfunction and insulin resistance represents one of the most common endocrine disorders in close association with metabolic dysfunction in premenopausal women.

AIM OF THE STUDY

The present study aimed to investigate the preventive effect of FTZ on letrozole-induced experimental PCOS and its associated insulin resistance in mice.

MATERIALS AND METHODS

Prepubertal female mice in the experimental groups (letrozole and FTZ) received continuous infusion of letrozole (50 μg/day) for 35 days. FTZ was administrated to mice by oral gavage daily at dosage of 2.892 g/kg body weight for 5 weeks. All groups of mice were fed a high-fat diet (HFD). Ovary and adipose tissue were collected from all mice after 5 weeks and adiponectin, testosterone, estradiol, and luteinizing hormone level determined.

RESULTS

Letrozole-induced morphological changes in the ovary, including a decreased number of corpora lutea and antral follicles, and increased cystic follicles, were significantly attenuated in FTZ-treated mice. Additionally, FTZ treatment notably reversed PCOS-related disruption of estrous status. PCOS-related insulin resistance was markedly alleviated. Mechanistically, FTZ treatment notably enhanced circulating level and transcriptional abundance of adiponectin in adipose tissue, thereby orchestrating fat-ovary crosstalk.

CONCLUSIONS

Our data collectively demonstrate that FTZ exerted preventive benefits in an experimental model of PCOS, at least partially by potentiating the production of adiponectin from adipose tissues. This suggests that FTZ is a promising treatment for PCOS.

Polycystic ovary syndrome associated with increased adiposity interferes with serum levels of TNF-alpha and IL-6 differently from leptin and adiponectin

Objective The aim of this study was to investigate polycystic ovary syndrome (PCOS) and to explore the relationship between body fat percentage and metabolic markers. Subjects and methods Sedentary women were assigned to PCOS (N = 60) and CONTROL (N = 60) groups. Each group was subdivided into three subgroups according to body fat percentage (22-27%, 27-32% and 32-37%). The protocol consisted of assessments of glucose, insulin, androgens, follicle stimulating hormone (FSH), luteinizing hormone (LH), 17-hydroxyprogesterone (17-OHP), leptin, adiponectin, tumor necrosis factor (TNF-α) and interleukin-6 (IL-6). Results The PCOS subgroups showed higher concentrations of androgens, LH and 17-OHP. Leptin showed direct relationship with increased body fat percentage, whereas adiponectin showed the inverse effect. However, both were unaffected by PCOS. TNF-α and IL-6 were higher in PCOS women and showed a direct relationship with increased body fat percentage. Glucose showed direct relationship with body fat percentage, whereas insulin presented higher values in PCOS women and direct relationship with increased body fat percentage. Conclusions Our findings indicate that PCOS and body fat percentage directly influence concentrations of insulin, TNF-α and IL-6, whereas leptin and adiponectin are influenced only by the increase in body fat percentage in these women. Arch Endocrinol Metab. 2020;64(1):4-10.

Undernutrition and hyperandrogenism during pregnancy: Role in programming of cardiovascular disease and infertility

Maternal nutritional status programs the development of several systems in female offspring, with effects that depend on the severity, duration, and window of development when the nutritional perturbation is imposed. On the basis of the developmental origins of health and disease concept, we hypothesize that gestational low caloric intake may induce maternal subclinical hyperandrogenism during early pregnancy and compromise cardiovascular health and fertility in the female offspring. To examine this possibility, a literature search for human and animal studies was conducted using two electronic databases, PubMed and Cochrane until April 2019 to address the following questions: (a) Do androgens have a developmental role in cardiovascular and ovarian development? (b) Is excess maternal testosterone linked to cardiovascular disease and infertility? and (c) Could early pregnancy undernutrition enhance maternal androgen production and compromise health and fertility in female offspring? The observations reviewed, establish a potential causative link between maternal undernutrition and subclinical hyperandrogenism with hypertension and reduced ovarian reserve in the progeny. Further studies in appropriate models are needed to better understand whether low energy intake and subclinical maternal hyperandrogenism during early pregnancy can negatively affect the health of the female offspring.

A Low Glycemic Index Decreases Inflammation by Increasing the Concentration of Uric Acid and the Activity of Glutathione Peroxidase (GPx3) in Patients with Polycystic Ovary Syndrome (PCOS)

Introduction: According to a review of the literature, there is a lack of data on the mechanisms that participate in the suppression of inflammation that accompanies polycystic ovary syndrome (PCOS). Additionally, the changes in oxidative status resulting from a low-calorie diet have not been studied in a group of women with PCOS, and the oxidation and reduction processes associated with PCOS have not been explained. Material and methods: The study involved 49 women who were diagnosed with PCOS according to Rotterdam’s criteria, and 24 women voluntarily agreed to a three-month dietary intervention. The dietary intervention was carried out for 3 months. Glutathione peroxidase (GPx3) activity, the Ferric reducing ability of plasma, and uric acid concentration were measured spectrophotometrically both before and after the intervention. Statistical analysis was performed with the Statistica 10.0 software package, and a Pearson’s correlation matrix was generated. Results: A lower concentration of GPx3 was observed in women with PCOS (before the dietetic intervention began) compared with the GPx3 levels in healthy women. A relationship was shown between GPx3 levels and the concentration of prolactin, insulin on fasting, and triglycerides. After the dietary intervention, increases in uric acid and GPx3 activity were noted, as well as numerous relationships between anthropometric and biochemical parameters. The ferric reducing/antioxidant power did not change significantly. Conclusions: Inhibiting the effect of prolactin (by the level of reactive oxygen species) on the activity of GPx3 could be a starting point for the increase in antioxidative stress and the development of the inflammatory state associated with PCOS pathophysiology. Following a low-calorie diet with a lower glycemic index is proposed to silence inflammation by increasing the concentration of uric acid. During GPx3 mobilization, women with PCOS have a higher demand for selenium, and its deficiencies may contribute to disordered thyroid hormone synthesis. The three-month dietary intervention did not silence redox processes in the examined group of women.

Mechanisms of Adiponectin Action in Fertility: An Overview from Gametogenesis to Gestation in Humans and Animal Models in Normal and Pathological Conditions

Adiponectin is the most abundant plasma adipokine. It mainly derives from white adipose tissue and plays a key role in the control of energy metabolism thanks to its insulin-sensitising, anti-inflammatory, and antiatherogenic properties. In vitro and in vivo evidence shows that adiponectin could also be one of the hormones controlling the interaction between energy balance and fertility in several species, including humans. Indeed, its two receptors—AdipoR1 and AdipoR2—are expressed in hypothalamic–pituitary–gonadal axis and their activation regulates Kiss, GnRH and gonadotropin expression and/or secretion. In male gonads, adiponectin modulates several functions of both somatic and germ cells, such as steroidogenesis, proliferation, apoptosis, and oxidative stress. In females, it controls steroidogenesis of ovarian granulosa and theca cells, oocyte maturation, and embryo development. Adiponectin receptors were also found in placental and endometrial cells, suggesting that this adipokine might play a crucial role in embryo implantation, trophoblast invasion and foetal growth. The aim of this review is to characterise adiponectin expression and its mechanism of action in male and female reproductive tract. Further, since features of metabolic syndrome are associated with some reproductive diseases, such as polycystic ovary syndrome, gestational diabetes mellitus, preeclampsia, endometriosis, foetal growth restriction and ovarian and endometrial cancers, evidence regarding the emerging role of adiponectin in these disorders is also discussed.

Adiponectin: A New Regulator of Female Reproductive System

Adiponectin is the hormone that belongs to the group of adipokines, chemical agents mainly derived from the white adipose tissue. The hormone plays pleiotropic roles in the organism, but the most important function of adiponectin is the control of energy metabolism. The presence of adiponectin and its receptors in the structures responsible for the regulation of female reproductive functions, such as hypothalamic-pituitary-gonadal (HPG) axis, indicates that adiponectin may be involved in the female fertility regulation. The growing body of evidence suggests also that adiponectin action is dependent on the actual and hormonal status of the animal. Present study presents the current knowledge about the presence and role of adiponectin system (adiponectin and its receptors: AdipoR1 and AdipoR2) in the ovaries, oviduct, and uterus, as well as in the hypothalamus and pituitary, the higher branches of HPG axis, involved in the female fertility regulation.