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Sucquart IE, Coyle C, Rodriguez Paris V, Prescott M, Glendining KA, Potapov K, Begg DP, Gilchrist RB, Walters KA, Campbell RE. Investigating GABA Neuron-Specific Androgen Receptor Knockout in two Hyperandrogenic Models of PCOS. Endocrinology 2024; 165:bqae060. [PMID: 38788194 PMCID: PMC11151696 DOI: 10.1210/endocr/bqae060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 05/20/2024] [Accepted: 05/20/2024] [Indexed: 05/26/2024]
Abstract
Androgen excess is a hallmark feature of polycystic ovary syndrome (PCOS), the most common form of anovulatory infertility. Clinical and preclinical evidence links developmental or chronic exposure to hyperandrogenism with programming and evoking the reproductive and metabolic traits of PCOS. While critical androgen targets remain to be determined, central GABAergic neurons are postulated to be involved. Here, we tested the hypothesis that androgen signaling in GABAergic neurons is critical in PCOS pathogenesis in 2 well-characterized hyperandrogenic mouse models of PCOS. Using cre-lox transgenics, GABA-specific androgen receptor knockout (GABARKO) mice were generated and exposed to either acute prenatal androgen excess (PNA) or chronic peripubertal androgen excess (PPA). Females were phenotyped for reproductive and metabolic features associated with each model and brains of PNA mice were assessed for elevated GABAergic input to gonadotropin-releasing hormone (GnRH) neurons. Reproductive and metabolic dysfunction induced by PPA, including acyclicity, absence of corpora lutea, obesity, adipocyte hypertrophy, and impaired glucose homeostasis, was not different between GABARKO and wild-type (WT) mice. In PNA mice, acyclicity remained in GABARKO mice while ovarian morphology and luteinizing hormone secretion was not significantly impacted by PNA or genotype. However, PNA predictably increased the density of putative GABAergic synapses to GnRH neurons in adult WT mice, and this PNA-induced plasticity was absent in GABARKO mice. Together, these findings suggest that while direct androgen signaling in GABA neurons is largely not required for the development of PCOS-like traits in androgenized models of PCOS, developmental programming of GnRH neuron innervation is dependent upon androgen signaling in GABA neurons.
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Affiliation(s)
- Irene E Sucquart
- Fertility & Research Centre, School of Clinical Medicine, University of New South Wales Sydney, Randwick, NSW 2031, Australia
| | - Chris Coyle
- Centre of Neuroendocrinology and Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand 9054
| | - Valentina Rodriguez Paris
- Fertility & Research Centre, School of Clinical Medicine, University of New South Wales Sydney, Randwick, NSW 2031, Australia
- School of Biomedical Sciences, University of New South Wales Sydney, Randwick, NSW 2052, Australia
| | - Melanie Prescott
- Centre of Neuroendocrinology and Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand 9054
| | - Kelly A Glendining
- Centre of Neuroendocrinology and Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand 9054
| | - Kyoko Potapov
- Centre of Neuroendocrinology and Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand 9054
| | - Denovan P Begg
- Department of Behavioural Neuroscience, School of Psychology, University of New South Wales Sydney, Randwick, NSW, Australia
| | - Robert B Gilchrist
- Fertility & Research Centre, School of Clinical Medicine, University of New South Wales Sydney, Randwick, NSW 2031, Australia
| | - Kirsty A Walters
- Fertility & Research Centre, School of Clinical Medicine, University of New South Wales Sydney, Randwick, NSW 2031, Australia
| | - Rebecca E Campbell
- Centre of Neuroendocrinology and Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand 9054
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Bodnar RJ. Endogenous opiates and behavior: 2021. Peptides 2023; 164:171004. [PMID: 36990387 DOI: 10.1016/j.peptides.2023.171004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/23/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023]
Abstract
This paper is the forty-fourth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2021 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonizts and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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Cara AL, Burger LL, Beekly BG, Allen SJ, Henson EL, Auchus RJ, Myers MG, Moenter SM, Elias CF. Deletion of Androgen Receptor in LepRb Cells Improves Estrous Cycles in Prenatally Androgenized Mice. Endocrinology 2023; 164:bqad015. [PMID: 36683455 PMCID: PMC10091504 DOI: 10.1210/endocr/bqad015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 01/24/2023]
Abstract
Androgens are steroid hormones crucial for sexual differentiation of the brain and reproductive function. In excess, however, androgens may decrease fertility as observed in polycystic ovary syndrome, a common endocrine disorder characterized by oligo/anovulation and/or polycystic ovaries. Hyperandrogenism may also disrupt energy homeostasis, inducing higher central adiposity, insulin resistance, and glucose intolerance, which may exacerbate reproductive dysfunction. Androgens bind to androgen receptors (ARs), which are expressed in many reproductive and metabolic tissues, including brain sites that regulate the hypothalamo-pituitary-gonadal axis and energy homeostasis. The neuronal populations affected by androgen excess, however, have not been defined. We and others have shown that, in mice, AR is highly expressed in leptin receptor (LepRb) neurons, particularly in the arcuate (ARH) and the ventral premammillary nuclei (PMv). Here, we assessed if LepRb neurons, which are critical in the central regulation of energy homeostasis and exert permissive actions on puberty and fertility, have a role in the pathogenesis of female hyperandrogenism. Prenatally androgenized (PNA) mice lacking AR in LepRb cells (LepRbΔAR) show no changes in body mass, body composition, glucose homeostasis, or sexual maturation. They do show, however, a remarkable improvement of estrous cycles combined with normalization of ovary morphology compared to PNA controls. Our findings indicate that the prenatal androgenization effects on adult reproductive physiology (ie, anestrus and anovulation) are mediated by a subpopulation of LepRb neurons directly sensitive to androgens. They also suggest that the effects of hyperandrogenism on sexual maturation and reproductive function in adult females are controlled by distinct neural circuits.
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Affiliation(s)
- Alexandra L Cara
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California 90095, USA
| | - Laura L Burger
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Bethany G Beekly
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Susan J Allen
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Emily L Henson
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Richard J Auchus
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Martin G Myers
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Suzanne M Moenter
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Carol F Elias
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan 48109, USA
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GnRH Neuron Excitability and Action Potential Properties Change with Development But Are Not Affected by Prenatal Androgen Exposure. eNeuro 2022; 9:ENEURO.0362-22.2022. [PMID: 36446571 PMCID: PMC9765403 DOI: 10.1523/eneuro.0362-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/09/2022] [Accepted: 11/17/2022] [Indexed: 12/03/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) neurons produce the final output from the brain to control pituitary gonadotropin secretion and thus regulate reproduction. Disruptions to gonadotropin secretion contribute to infertility, including polycystic ovary syndrome (PCOS) and idiopathic hypogonadotropic hypogonadism. PCOS is the leading cause of infertility in women and symptoms resembling PCOS are observed in girls at or near the time of pubertal onset, suggesting that alterations to the system likely occurred by that developmental period. Prenatally androgenized (PNA) female mice recapitulate many of the neuroendocrine phenotypes observed in PCOS, including altered time of puberty, disrupted reproductive cycles, increased circulating levels of testosterone, and altered gonadotropin secretion patterns. We tested the hypotheses that the intrinsic properties of GnRH neurons change with puberty and with PNA treatment. Whole-cell current-clamp recordings were made from GnRH neurons in brain slices from control and PNA females before puberty at three weeks of age and in adulthood to measure GnRH neuron excitability and action potential (AP) properties. GnRH neurons from adult females were more excitable and required less current to initiate action potential firing compared with three-week-old females. Further, the afterhyperpolarization (AHP) potential of the first spike was larger and its peak was delayed in adulthood. These results indicate development, not PNA, is a primary driver of changes to GnRH neuron intrinsic properties and suggest there may be developmentally-induced changes to voltage-gated ion channels in GnRH neurons that alter how these cells respond to synaptic input.
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Moore AM. Impaired steroid hormone feedback in polycystic ovary syndrome: Evidence from preclinical models for abnormalities within central circuits controlling fertility. Clin Endocrinol (Oxf) 2022; 97:199-207. [PMID: 35349177 DOI: 10.1111/cen.14711] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/09/2022] [Accepted: 02/18/2022] [Indexed: 12/24/2022]
Abstract
Polycystic ovary syndrome (PCOS) is the most common endocrinopathy and cause of infertility in women of reproductive age worldwide. Despite diagnostic features of anovulation, polycystic ovarian morphology, and high androgen secretion indicating the syndrome are the result of ovarian dysfunction, alterations to central neuroendocrine circuits that control reproductive capacity may drive PCOS symptoms. Resistance of gonadotrophin-releasing hormone (GnRH) neurons in the hypothalamus to inhibition by sex steroid hormone-negative feedback leads to a rapid frequency of pulsatile gonadotrophin secretion, which, in turn, drives the ovarian features of the disease. As GnRH neurons do not express steroid hormone receptors, impaired negative feedback is hypothesized to occur within an upstream network that controls GnRH pulse generation. This review will discuss the latest work from preclinical animal models of PCOS used to dissect the specific central mechanisms involved in impaired steroid hormone feedback. In particular, this review will focus on research that indicates neurons in the arcuate nucleus of the hypothalamus that express Kisspeptin, Neurokinin B and Dynorphin (KNDy cells) or γ-aminobutyric acid are targets of androgen-mediated impairment of steroid hormone feedback. Finally, this review will explore the development of therapeutic agents targeting neurons that control LH pulse frequency to resolve PCOS symptoms in the clinic.
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Affiliation(s)
- Aleisha M Moore
- Department of Biological Sciences, Brain Health Research Institute, Kent State University, Kent, Ohio, USA
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McCartney CR, Campbell RE, Marshall JC, Moenter SM. The role of gonadotropin-releasing hormone neurons in polycystic ovary syndrome. J Neuroendocrinol 2022; 34:e13093. [PMID: 35083794 PMCID: PMC9232905 DOI: 10.1111/jne.13093] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/21/2021] [Accepted: 01/11/2022] [Indexed: 01/28/2023]
Abstract
Given the critical central role of gonadotropin-releasing hormone (GnRH) neurons in fertility, it is not surprising that the GnRH neural network is implicated in the pathology of polycystic ovary syndrome (PCOS), the most common cause of anovulatory infertility. Although many symptoms of PCOS relate most proximately to ovarian dysfunction, the central reproductive neuroendocrine system ultimately drives ovarian function through its regulation of anterior pituitary gonadotropin release. The typical cyclical changes in frequency of GnRH release are often absent in women with PCOS, resulting in a persistent high-frequency drive promoting gonadotropin changes (i.e., relatively high luteinizing hormone and relatively low follicle-stimulating hormone concentrations) that contribute to ovarian hyperandrogenemia and ovulatory dysfunction. However, the specific mechanisms underpinning GnRH neuron dysfunction in PCOS remain unclear. Here, we summarize several preclinical and clinical studies that explore the causes of aberrant GnRH secretion in PCOS and the role of disordered GnRH secretion in PCOS pathophysiology.
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Affiliation(s)
- Christopher R. McCartney
- Center for Research in Reproduction and Department of MedicineUniversity of Virginia School of MedicineCharlottesvilleVAUSA
| | - Rebecca E. Campbell
- Centre for Neuroendocrinology and Department of PhysiologySchool of Biomedical SciencesUniversity of OtagoDunedinNew Zealand
| | - John C. Marshall
- Center for Research in Reproduction and Department of MedicineUniversity of Virginia School of MedicineCharlottesvilleVAUSA
| | - Suzanne M. Moenter
- Departments of Molecular & Integrative PhysiologyInternal MedicineObstetrics and GynecologyUniversity of MichiganAnn ArborMIUSA
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Jamieson BB, Moore AM, Lohr DB, Thomas SX, Coolen LM, Lehman MN, Campbell RE, Piet R. Prenatal androgen treatment impairs the suprachiasmatic nucleus arginine-vasopressin to kisspeptin neuron circuit in female mice. Front Endocrinol (Lausanne) 2022; 13:951344. [PMID: 35992143 PMCID: PMC9388912 DOI: 10.3389/fendo.2022.951344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/06/2022] [Indexed: 01/13/2023] Open
Abstract
Polycystic ovary syndrome (PCOS) is associated with elevated androgen and luteinizing hormone (LH) secretion and with oligo/anovulation. Evidence indicates that elevated androgens impair sex steroid hormone feedback regulation of pulsatile LH secretion. Hyperandrogenemia in PCOS may also disrupt the preovulatory LH surge. The mechanisms through which this might occur, however, are not fully understood. Kisspeptin (KISS1) neurons of the rostral periventricular area of the third ventricle (RP3V) convey hormonal cues to gonadotropin-releasing hormone (GnRH) neurons. In rodents, the preovulatory surge is triggered by these hormonal cues and coincident timing signals from the central circadian clock in the suprachiasmatic nucleus (SCN). Timing signals are relayed to GnRH neurons, in part, via projections from SCN arginine-vasopressin (AVP) neurons to RP3VKISS1 neurons. Because rodent SCN cells express androgen receptors (AR), we hypothesized that these circuits are impaired by elevated androgens in a mouse model of PCOS. In prenatally androgen-treated (PNA) female mice, SCN Ar expression was significantly increased compared to that found in prenatally vehicle-treated mice. A similar trend was seen in the number of Avp-positive SCN cells expressing Ar. In the RP3V, the number of kisspeptin neurons was preserved. Anterograde tract-tracing, however, revealed reduced SCNAVP neuron projections to the RP3V and a significantly lower proportion of RP3VKISS1 neurons with close appositions from SCNAVP fibers. Functional assessments showed, on the other hand, that RP3VKISS1 neuron responses to AVP were maintained in PNA mice. These findings indicate that PNA changes some of the neural circuits that regulate the preovulatory surge. These impairments might contribute to ovulatory dysfunction in PNA mice modeling PCOS.
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Affiliation(s)
- Bradley B. Jamieson
- Centre for Neuroendocrinology and Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Aleisha M. Moore
- Brain Health Research Institute and Department of Biological Sciences, Kent State University, Kent, OH, United States
| | - Dayanara B. Lohr
- Brain Health Research Institute and Department of Biological Sciences, Kent State University, Kent, OH, United States
| | - Simone X. Thomas
- Centre for Neuroendocrinology and Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Lique M. Coolen
- Brain Health Research Institute and Department of Biological Sciences, Kent State University, Kent, OH, United States
| | - Michael N. Lehman
- Brain Health Research Institute and Department of Biological Sciences, Kent State University, Kent, OH, United States
| | - Rebecca E. Campbell
- Centre for Neuroendocrinology and Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Richard Piet
- Centre for Neuroendocrinology and Department of Physiology, University of Otago, Dunedin, New Zealand
- Brain Health Research Institute and Department of Biological Sciences, Kent State University, Kent, OH, United States
- *Correspondence: Richard Piet,
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Stevenson H, Bartram S, Charalambides MM, Murthy S, Petitt T, Pradeep A, Vineall O, Abaraonye I, Lancaster A, Koysombat K, Patel B, Abbara A. Kisspeptin-neuron control of LH pulsatility and ovulation. Front Endocrinol (Lausanne) 2022; 13:951938. [PMID: 36479214 PMCID: PMC9721495 DOI: 10.3389/fendo.2022.951938] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 11/01/2022] [Indexed: 11/22/2022] Open
Abstract
Feedback from oestradiol (E2) plays a critical role in the regulation of major events in the physiological menstrual cycle including the release of gonadotrophins to stimulate follicular growth, and the mid-cycle luteinising hormone (LH) surge that leads to ovulation. E2 predominantly exerts its action via oestrogen receptor-alpha (ERα), however, as gonadotrophin releasing hormone (GnRH) neurons lack ERα, E2-feedback is posited to be indirectly mediated via upstream neurons. Kisspeptin (KP) is a neuropeptide expressed in hypothalamic KP-neurons that control GnRH secretion and plays a key role in the central mechanism regulating the hypothalamic-pituitary-gonadal (HPG) axis. In the rodent arcuate (ARC) nucleus, KP is co-expressed with Neurokinin B and Dynorphin; and thus, these neurons are termed 'Kisspeptin-Neurokinin B-Dynorphin' (KNDy) neurons. ARC KP-neurons function as the 'GnRH pulse generator' to regulate GnRH pulsatility, as well as mediating negative feedback from E2. A second KP neuronal population is present in the rostral periventricular area of the third ventricle (RP3V), which includes anteroventral periventricular (AVPV) nucleus and preoptic area neurons. These RP3V KP-neurons mediate positive feedback to induce the mid-cycle luteinising hormone (LH) surge and subsequent ovulation. Here, we describe the role of KP-neurons in these two regions in mediating this differential feedback from oestrogens. We conclude by considering reproductive diseases for which exploitation of these mechanisms could yield future therapies.
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