Prenatal androgen exposure alters KNDy neurons and their afferent network in a model of polycystic ovarian syndrome

Abstract Polycystic ovarian syndrome (PCOS), the most common endocrinopathy affecting women worldwide, is characterized by elevated luteinizing hormone (LH) pulse frequency due to the impaired suppression of gonadotrophin-releasing hormone (GnRH) release by steroid hormone negative feedback. Although neurons that co-express kisspeptin, neurokinin B and dynorphin (KNDy cells) were recently defined as the GnRH/LH pulse generator, little is understood about their role in the pathogenesis of PCOS. We used a prenatal androgen-treated (PNA) mouse model of PCOS to determine whether changes in KNDy neurons or their afferent network underlie altered negative feedback. First, we identified elevated androgen receptor gene expression in KNDy cells of PNA mice, whereas progesterone receptor and dynorphin gene expression was significantly reduced, suggesting elevated androgens in PCOS disrupt progesterone negative feedback via direct actions upon KNDy cells. Second, we discovered GABAergic and glutamatergic synaptic input to KNDy neurons was reduced in PNA mice. Retrograde monosynaptic tract-tracing revealed a dramatic reduction in input originates from sexually dimorphic afferents in the preoptic area, anteroventral periventricular nucleus, anterior hypothalamic area and lateral hypothalamus. These results reveal two sites of neuronal alterations potentially responsible for defects in negative feedback in PCOS: changes in gene expression within KNDy neurons, and changes in synaptic inputs from steroid hormone-responsive hypothalamic regions. How each of these changes contribute to the neuroendocrine phenotype seen in in PCOS, and the role of specific sets of upstream KNDy afferents in the process, remains to be determined.

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Prenatal Testosterone Exposure Alters GABAergic Synaptic Inputs to GnRH and KNDy Neurons in a Sheep Model of Polycystic Ovarian Syndrome

Endocrinology ◽

10.1210/en.2019-00137 ◽

2019 ◽

Vol 160 (11) ◽

pp. 2529-2542 ◽

Cited By ~ 6

Author(s):

Danielle T Porter ◽

Aleisha M Moore ◽

Jade A Cobern ◽

Vasantha Padmanabhan ◽

Robert L Goodman ◽

...

Keyword(s):

Polycystic Ovarian Syndrome ◽

Pulse Generator ◽

Pulse Frequency ◽

Sheep Model ◽

Neurotransmitter System ◽

Prenatal Testosterone ◽

Gnrh Neurons ◽

Gabaergic Synapses ◽

Kndy Neurons ◽

Ovarian Syndrome

Abstract Prenatal testosterone (T)-treated female sheep display reproductive deficits similar to women with polycystic ovarian syndrome (PCOS), including an increase in LH pulse frequency due to actions of the central GnRH pulse generator. In this study, we used multiple-label immunocytochemistry to investigate the possibility of changes in the γ-aminobutyric acid (GABA) neurotransmitter system at two key components of the GnRH pulse generator in prenatal T-treated sheep: kisspeptin/neurokinin B/dynorphin (KNDy) neurons of the arcuate nucleus, and GnRH neurons in the preoptic area (POA) and mediobasal hypothalamus (MBH). We observed a significant decrease and increase, respectively, in the number of GABAergic synapses onto POA and MBH GnRH neurons in prenatal T-treated ewes; additionally, there was a significant increase in the number of GABAergic inputs onto KNDy neurons. To determine the actions of GABA on GnRH and KNDy neurons, we examined colocalization with the chloride transporters NKCC1 and KCC2, which indicate stimulatory or inhibitory activation of neurons by GABA, respectively. Most GnRH neurons in both POA and MBH colocalized NKCC1 cotransporter whereas none contained the KCC2 cotransporter. Most KNDy neurons colocalized either NKCC1 or KCC2, and 28% of the KNDy population contained NKCC1 alone. Therefore, we suggest that, as in the mouse, GABA in the sheep is stimulatory to GnRH neurons, as well as to a subset of KNDy neurons. Increased numbers of stimulatory GABAergic inputs to both MBH GnRH and KNDy neurons in prenatal T-treated animals may contribute to alterations in steroid feedback control and increased GnRH/LH pulse frequency seen in this animal model of PCOS.

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Troglitazone, an Insulin-Sensitizing Thiazolidinedione, Represses Combined Stimulation by LH and Insulin of de Novo Androgen Biosynthesis by Thecal Cells in Vitro

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.87.3.8308 ◽

2002 ◽

Vol 87 (3) ◽

pp. 1129-1133 ◽

Cited By ~ 29

Author(s):

Johannes D. Veldhuis ◽

George Zhang ◽

James C. Garmey

Keyword(s):

Gene Expression ◽

Polycystic Ovarian Syndrome ◽

De Novo ◽

Drug Concentrations ◽

Thecal Cells ◽

Cyp17 Gene ◽

Pparγ Agonist ◽

Ovarian Syndrome ◽

Prostaglandin J2

Polycystic ovarian syndrome (anovulatory hyperandrogenism) is marked by adolescent onset of systemic hyperinsulinism, oligoovulation, hirsutism, excessive LH and androgen secretion, and variable reduction in fertility. Insulin and LH are believed to act in concert to promote ovarian androgen hypersecretion in this disorder. Administration of troglitazone, an insulin-sensitizing agent and putative PPARγ agonist, can decrease hyperinsulinism, suppress T production, and ameliorate oligoovulation in some women with this endocrinopathy. The present study tests the hypothesis that troglitazone directly inhibits de novo androgen biosynthesis stimulated jointly by LH and insulin in primary cultures of (porcine) thecal cells. We show that troglitazone dose-dependently antagonizes LH/insulin’s combined stimulation of androstenedione and T production by thecal cells in vitro. Consistent steroidogenic inhibition of 80–95% was achieved at drug concentrations of 3–6.8 μm (P < 0.001). Exposure of thecal cells to the thiazolidinedione derivative also blocked bihormonally stimulated accumulation of CYP17 (cytochrome P450 17 α-hydroxylase/C17–20 lyase) gene expression, as reflected by decreased accumulation of cognate heterogeneous nuclear RNA and mRNA (by 30–65%; P < 0.05). Moreover, troglitazone suppressed LH/insulin-induced phosphorylation of the 52-kDa immunoprecipitated CYP17 enzyme by 88% (P < 0.001). A putative natural agonist of PPARγ nuclear transcription, 15-deoxy-δ-12,14-prostaglandin J2, also inhibited LH/insulin-driven androstenedione biosynthesis and CYP17 gene expression in thecal cells. In conclusion, a synthetic thiazolidinedione (troglitazone) and a natural ligand of PPARγ (15-deoxy-δ-12,14-prostaglandin J2) effectively impede the concerted stimulation by LH and insulin of in vitro thecal cell androgen production, CYP17 gene expression, and CYP17 protein phosphorylation. This ensemble of inhibitory actions on LH/insulin-stimulated steroidogenesis offers a plausible mechanistic basis for at least part of the observed clinical efficacy of troglitazone in mitigating androgen excess in women with polycystic ovarian syndrome.

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Correlation of serum androgen and gonadotropin with anti-mullerian hormone in polycystic ovarian syndrome in Eastern Indian population

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20195918 ◽

2019 ◽

Vol 8 (1) ◽

pp. 256

Author(s):

Somnath Singh Raghuvanshi ◽

Anirban Sinha ◽

Animesh Maiti ◽

Partha Pratim Chakraborty ◽

Asish Kumar Basu ◽

...

Keyword(s):

Polycystic Ovary Syndrome ◽

Polycystic Ovarian Syndrome ◽

Pulse Generator ◽

Polycystic Ovary ◽

Serum Testosterone ◽

Pulse Frequency ◽

Strong Positive Correlation ◽

Ovary Syndrome ◽

Cross Sectional ◽

Ovarian Syndrome

Background: Ovarian steroidogenesis requires gonadotropin stimulation, Luteinizing Hormone (LH) is a key factor in the hyperandrogenaemia of the polycystic ovary syndrome. Progesterone is the primary regulator of Gonadotropin-Releasing Hormone (GnRH) pulse frequency; however, in the polycystic ovary syndrome, the GnRH pulse generator is relatively resistant to the negative feedback effects of progesterone. Study aims to evaluate the association of Anti-mullerian hormone with serum androgen and gonadotropin level in adolescents and young women of Polycystic Ovary Syndrome (PCOS).Methods: This was a single centre observational Cross-sectional study carried out in the department of Endocrinology and metabolism, Medical College, Kolkata from March 2017 to January 2019. Total number of study subjects were 207 out of which 138 were cases.Results: The AMH had strong positive correlation with serum testosterone in both case and control groups (r 0.542, p<0.001 and r 0.57, p<0.001) respectively .After the adjustment of age and BMI , the AMH moderately positive but extremely significant correlation with serum testosterone as compare to control.Conclusions: Hyperandrogenaemia and higher ratio of LH and FSH associated with higher serum AMH level is associated with the higher serum AMH in polycystic ovarian syndrome.

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Investigation Trp64Arg polymorphism of the beta 3-adrenergic receptor gene in nonobese women with polycystic ovarian syndrome

International Journal of Reproductive BioMedicine ◽

10.18502/ijrm.v18i3.6712 ◽

2020 ◽

Author(s):

Farideh Zafari Zangeneh ◽

Maryam Sarmast Shoushtari ◽

Sahar Shojaee ◽

Elahe Aboutorabi

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Adrenergic Receptor ◽

Polycystic Ovarian Syndrome ◽

Receptor Gene ◽

Gene Bank ◽

Control Group ◽

Trp64arg Polymorphism ◽

Ovarian Syndrome ◽

Adrenergic Receptor Gene

Background: Polycystic ovary syndrome (PCOS) is a multifactorial and heterogeneous disease that has a potent inheritable component based on familial clustering. Despite many studies in the genetic field of PCOS, the genes that are involved in the causes of this syndrome have not been thoroughly investigated. Objective: The purpose of this study was to establish the occurrence of the Trp64Arg polymorphism of beta3 adrenergic receptor in non-obese women with PCOS. Materials and Methods: This cross-sectional study was performed on 100 women with PCOS and normal women as the control group in Imam Khomeini Hospital of Tehran in 2016-2017. Peripheral blood sample (2 cc) was obtained from two groups for genomic DNA based on the gene bank. Polymorphisms were genotyped by of using ADRB3 Trp64Arg. Then the DNA was extracted by genomic kiagen kit. The primer was analyzed for PCR based on gene bank by using Primer3 software and then confirmed by primer Blast tool at NCBI site to conformity to the beta-3 adrenergic receptor gene. The protein changes were assessment by the Clastal W software. Results: The sequence analysis presented in NCBI, transcript variant 1, with the code NM_000025.2, shows changes in the amino acid sequence of exon 1 in women with PCOS. Polymorphism in the codon 64 encoding the amino acid tryptophan (W) occurred in the nucleotide c.T190C, which changed the nucleotide T to C and then the amino acid sequence of the tryptophan was altered to arginine pW64R. Conclusion: T-C polymorphism is evident in the codon 64 of the adrenergic β3 receptor in patients with PCOS. Therefore, Beta3 adrenergic receptor gene polymorphism (Thr164Ile) associates with this syndrome in nonobese women. Key words: Codon 64, Beta-3 adrenergic receptor, Polymorphism, Polycystic ovarian syndrome.

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