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Garcia C, Velez LM, Ujagar N, Del Mundo Z, Nguyen T, Fox C, Mark A, Fisch KM, Lawson MA, Duleba AJ, Seldin MM, Nicholas DA. Lipopolysaccharide-induced chronic inflammation increases female serum gonadotropins and shifts the pituitary transcriptomic landscape. Front Endocrinol (Lausanne) 2024; 14:1279878. [PMID: 38260148 PMCID: PMC10801245 DOI: 10.3389/fendo.2023.1279878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 11/15/2023] [Indexed: 01/24/2024] Open
Abstract
Introduction Female reproductive function depends on a choreographed sequence of hormonal secretion and action, where specific stresses such as inflammation exert profound disruptions. Specifically, acute LPS-induced inflammation inhibits gonadotropin production and secretion from the pituitary, thereby impacting the downstream production of sex hormones. These outcomes have only been observed in acute inflammatory stress and little is known about the mechanisms by which chronic inflammation affects reproduction. In this study we seek to understand the chronic effects of LPS on pituitary function and consequent luteinizing and follicle stimulating hormone secretion. Methods A chronic inflammatory state was induced in female mice by twice weekly injections with LPS over 6 weeks. Serum gonadotropins were measured and bulk RNAseq was performed on the pituitaries from these mice, along with basic measurements of reproductive biology. Results Surprisingly, serum luteinizing and follicle stimulating hormone was not inhibited and instead we found it was increased with repeated LPS treatments. Discussion Analysis of bulk RNA-sequencing of murine pituitary revealed paracrine activation of TGFβ pathways as a potential mechanism regulating FSH secretion in response to chronic LPS. These results provide a framework with which to begin dissecting the impacts of chronic inflammation on reproductive physiology.
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Affiliation(s)
- Christopher Garcia
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California Irvine, Irvine, CA, United States
| | - Leandro M. Velez
- Department of Biological Chemistry, University of California Irvine, Irvine, CA, United States
- Center for Epigenetics and Metabolism, University of California Irvine, Irvine, CA, United States
| | - Naveena Ujagar
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California Irvine, Irvine, CA, United States
| | - Zena Del Mundo
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California Irvine, Irvine, CA, United States
| | - Thu Nguyen
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California Irvine, Irvine, CA, United States
| | - Chelsea Fox
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Prisma Health Upstate/University of South Carolina School of Medicine Greenville, Greenville, SC, United States
| | - Adam Mark
- Center for Computational Biology & Bioinformatics, University of California San Diego, La Jolla, CA, United States
| | - Kathleen M. Fisch
- Center for Computational Biology & Bioinformatics, University of California San Diego, La Jolla, CA, United States
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Diego, La Jolla, CA, United States
| | - Mark A. Lawson
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Diego, La Jolla, CA, United States
| | - Antoni J. Duleba
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Diego, La Jolla, CA, United States
| | - Marcus M. Seldin
- Department of Biological Chemistry, University of California Irvine, Irvine, CA, United States
- Center for Epigenetics and Metabolism, University of California Irvine, Irvine, CA, United States
| | - Dequina A. Nicholas
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California Irvine, Irvine, CA, United States
- Center for Epigenetics and Metabolism, University of California Irvine, Irvine, CA, United States
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2
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MohanKumar SMJ, Murugan A, Palaniyappan A, MohanKumar PS. Role of cytokines and reactive oxygen species in brain aging. Mech Ageing Dev 2023; 214:111855. [PMID: 37541628 PMCID: PMC10528856 DOI: 10.1016/j.mad.2023.111855] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 07/24/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
Aging is a complex process that produces profound effects on the brain. Although a number of external factors can promote the initiation and progression of brain aging, peripheral and central changes in the immune cells with time, also play an important role. Immunosenescence, which is an age-associated decline in immune function and Inflammaging, a low-grade inflammatory state in the aging brain contribute to an elevation in cytokine and reactive oxygen species production. In this review, we focus on the pro-inflammatory state that is established in the brain as a consequence of these two phenomena and the resulting detrimental changes in brain structure, function and repair that lead to a decline in central and neuroendocrine function.
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Affiliation(s)
- Sheba M J MohanKumar
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
| | - Abarna Murugan
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Arunkumar Palaniyappan
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Puliyur S MohanKumar
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
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Carrasco RA, Breen KM. Allostasis in Neuroendocrine Systems Controlling Reproduction. Endocrinology 2023; 164:bqad125. [PMID: 37586095 PMCID: PMC10461221 DOI: 10.1210/endocr/bqad125] [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: 05/30/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 08/18/2023]
Abstract
Allostasis provides a supporting role to the homeostatic control of biological variables in mammalian species. While the concept of homeostasis is related to the control of variables within a set point or range that are essential to life, allostasis refers to systems that facilitate adaptation to challenges that the organism faces and the new requirements for survival. Essential for such adaptation is the role played by the brain in eliciting neural and neuroendocrine responses. Reproductive function is fundamental for the survival of species but is costly in energetic terms and requires a synchrony with an ever-changing environment. Thus, in many species reproductive function is blocked or delayed over immediate challenges. This review will cover the physiological systems and neuroendocrine pathways that supply allostatic control over reproductive neuroendocrine systems. Light, hypoxia, temperature, nutrition, psychosocial, and immune mediators influence the neuroendocrine control of reproductive functions through pathways that are confluent at the paraventricular nucleus; however, understanding of the integrative responses to these stimuli has not been clarified. Likely, the ultimate consequence of these allostatic mechanisms is the modification of kisspeptin and gonadotropin-releasing hormone neuronal activity, thus compromising reproduction function in the short term, while preserving species survivability.
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Affiliation(s)
- Rodrigo A Carrasco
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093-0674, USA
| | - Kellie M Breen
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093-0674, USA
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4
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King'uyu DN, Stephens SBZ, Kopec AM. Immune signaling in sex-specific neural and behavioral development: Adolescent opportunity. Curr Opin Neurobiol 2022; 77:102647. [PMID: 36332416 PMCID: PMC9893405 DOI: 10.1016/j.conb.2022.102647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 10/04/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022]
Abstract
Sex differences in neural and behavioral development are integral to understanding neurodevelopmental, mental health, and neurodegenerative disorders. Much of the literature has focused on late prenatal and early postnatal life as a critical juncture for establishing sex-specific developmental trajectories, and data are now clear that immune signaling plays a central role in establishing sex differences early in life. Adolescence is another developmental period during which sex differences arise. However, we know far less about how immune signaling plays a role in establishing sex differences during adolescence. Herein, we review well-defined examples of sex differences during adolescence and then survey the literature to speculate how immune signaling might be playing a role in defining sex-specific adolescent outcomes. We discuss open questions in the literature and propose experimental design tenets that may assist in better understanding adolescent neurodevelopment.
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Affiliation(s)
- David N King'uyu
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, USA
| | - Shannon B Z Stephens
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, USA. https://twitter.com/Stephens_Lab
| | - Ashley M Kopec
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, USA.
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5
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McCosh RB, O'Bryne KT, Karsch FJ, Breen KM. Regulation of the gonadotropin-releasing hormone neuron during stress. J Neuroendocrinol 2022; 34:e13098. [PMID: 35128742 PMCID: PMC9232848 DOI: 10.1111/jne.13098] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 11/30/2022]
Abstract
The effect of stress on reproduction and gonadal function has captivated investigators for almost 100 years. Following the identification of gonadotropin-releasing hormone (GnRH) 50 years ago, a niche research field emerged fixated on how stress impairs this central node controlling downstream pituitary and gonadal function. It is now clear that both episodic GnRH secretion in males and females and surge GnRH secretion in females are inhibited during a variety of stress types. There has been considerable advancement in our understanding of numerous stress-related signaling molecules and their ability to impair reproductive neuroendocrine activity during stress. Recently, much attention has turned to the effects of stress on two populations of kisspeptin neurons: the stimulatory afferents to GnRH neurons that regulate pulsatile and surge-type gonadotropin secretion. Indeed, future work is still required to fully construct the neuroanatomical framework underlying stress effects, directly or indirectly, on GnRH neuron function. The present review evaluates and synthesizes evidence related to stress-related signaling molecules acting directly on GnRH neurons. Here, we review the evidence for and against the action of a handful of signaling molecules as inhibitors of GnRH neuron function, including corticotropin-releasing hormone, urocortins, norepinephrine, cortisol/corticosterone, calcitonin gene-related peptide and arginine-phenylalanine-amide-related peptide-3.
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Affiliation(s)
- Richard B McCosh
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, La Jolla, CA, USA
| | - Kevin T O'Bryne
- Department of Women and Children's Health, Faculty of Life Sciences and Medicine, King's College London, Guy's Campus, London, UK
| | - Fred J Karsch
- Reproductive Sciences Program and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Kellie M Breen
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, La Jolla, CA, USA
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6
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Avet C, Paul EN, Garrel G, Grange-Messent V, L'Hôte D, Denoyelle C, Corre R, Dupret JM, Lanone S, Boczkowski J, Simon V, Cohen-Tannoudji J. Carbon Black Nanoparticles Selectively Alter Follicle-Stimulating Hormone Expression in vitro and in vivo in Female Mice. Front Neurosci 2021; 15:780698. [PMID: 34938157 PMCID: PMC8685435 DOI: 10.3389/fnins.2021.780698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/15/2021] [Indexed: 11/13/2022] Open
Abstract
Toxic effects of nanoparticles on female reproductive health have been documented but the underlying mechanisms still need to be clarified. Here, we investigated the effect of carbon black nanoparticles (CB NPs) on the pituitary gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are key regulators of gonadal gametogenesis and steroidogenesis. To that purpose, we subjected adult female mice to a weekly non-surgical intratracheal administration of CB NPs at an occupationally relevant dose over 4 weeks. We also analyzed the effects of CB NPs in vitro, using both primary cultures of pituitary cells and the LβT2 gonadotrope cell line. We report here that exposure to CB NPs does not disrupt estrous cyclicity but increases both circulating FSH levels and pituitary FSH β-subunit gene (Fshb) expression in female mice without altering circulating LH levels. Similarly, treatment of anterior pituitary or gonadotrope LβT2 cells with increasing concentrations of CB NPs dose-dependently up-regulates FSH but not LH gene expression or release. Moreover, CB NPs enhance the stimulatory effect of GnRH on Fshb expression in LβT2 cells without interfering with LH regulation. We provide evidence that CB NPs are internalized by LβT2 cells and rapidly activate the cAMP/PKA pathway. We further show that pharmacological inhibition of PKA significantly attenuates the stimulatory effect of CB NPs on Fshb expression. Altogether, our study demonstrates that exposure to CB NPs alters FSH but not LH expression and may thus lead to gonadotropin imbalance.
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Affiliation(s)
- Charlotte Avet
- Université de Paris, BFA, UMR 8251, CNRS, ERL U1133, Inserm, Paris, France
| | - Emmanuel N Paul
- Inserm U955, IMRB, U 955, Faculté de Médecine, équipe 04, Université Paris Est (UPEC), Créteil, France
| | - Ghislaine Garrel
- Université de Paris, BFA, UMR 8251, CNRS, ERL U1133, Inserm, Paris, France
| | - Valérie Grange-Messent
- Sorbonne Université, CNRS, Inserm, Neuroscience Paris Seine - Institut de Biologie Paris Seine, Paris, France
| | - David L'Hôte
- Université de Paris, BFA, UMR 8251, CNRS, ERL U1133, Inserm, Paris, France
| | - Chantal Denoyelle
- Université de Paris, BFA, UMR 8251, CNRS, ERL U1133, Inserm, Paris, France
| | - Raphaël Corre
- Université de Paris, BFA, UMR 8251, CNRS, ERL U1133, Inserm, Paris, France
| | | | - Sophie Lanone
- Inserm U955, IMRB, U 955, Faculté de Médecine, équipe 04, Université Paris Est (UPEC), Créteil, France
| | - Jorge Boczkowski
- Inserm U955, IMRB, U 955, Faculté de Médecine, équipe 04, Université Paris Est (UPEC), Créteil, France
| | - Violaine Simon
- Université de Paris, BFA, UMR 8251, CNRS, ERL U1133, Inserm, Paris, France
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7
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Phumsatitpong C, Wagenmaker ER, Moenter SM. Neuroendocrine interactions of the stress and reproductive axes. Front Neuroendocrinol 2021; 63:100928. [PMID: 34171353 PMCID: PMC8605987 DOI: 10.1016/j.yfrne.2021.100928] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 06/17/2021] [Accepted: 06/19/2021] [Indexed: 01/27/2023]
Abstract
Reproduction is controlled by a sequential regulation of the hypothalamo-pituitary-gonadal (HPG) axis. The HPG axis integrates multiple inputs to maintain proper reproductive functions. It has long been demonstrated that stress alters fertility. Nonetheless, the central mechanisms of how stress interacts with the reproductive system are not fully understood. One of the major pathways that is activated during the stress response is the hypothalamo-pituitary-adrenal (HPA) axis. In this review, we discuss several aspects of the interactions between these two neuroendocrine systems to offer insights to mechanisms of how the HPA and HPG axes interact. We have also included discussions of other systems, for example GABA-producing neurons, where they are informative to the overall picture of stress effects on reproduction.
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Affiliation(s)
- Chayarndorn Phumsatitpong
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Elizabeth R Wagenmaker
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Suzanne M Moenter
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States; Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, United States.
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8
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Kreisman MJ, Tadrousse KS, McCosh RB, Breen KM. Neuroendocrine Basis for Disrupted Ovarian Cyclicity in Female Mice During Chronic Undernutrition. Endocrinology 2021; 162:bqab103. [PMID: 34037744 PMCID: PMC8272537 DOI: 10.1210/endocr/bqab103] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Indexed: 11/19/2022]
Abstract
Chronic undernutrition is a type of metabolic stress that impairs reproduction in multiple species. Although energy balance and female reproductive capacity is recognized as tightly coupled, the neuroendocrine loci and molecular mechanisms that mediate ovarian cycle dysfunction during chronic undernutrition in adult females remain poorly understood. Here, we present a series of studies in which we tested the hypothesis that inhibition of kisspeptin (Kiss1) neurons, which are critical for controlling luteinizing hormone (LH) pulses and the preovulatory LH surge in females, underlies the impairment of the ovarian cycle by undernutrition. We first investigated the effect of chronic undernutrition (70% of unrestricted feed intake) on estrous cyclicity in intact female c57bl6 mice. Undernutrition caused a rapid cessation of ovarian cyclicity during the 2-week treatment, suppressing ovarian steroidogenesis and inhibiting ovulation. Using 2 well-defined estradiol-replacement paradigms, we directly tested the hypothesis that undernutrition inhibits Kiss1 neurons in the arcuate nucleus (ARCKiss1), which are required for LH pulses and in the anteroventral periventricular nucleus (AVPVKiss1), which are necessary for LH surge secretion. Undernutrition prevented LH pulses and impaired ARCKiss1 neuronal activation, using c-Fos as a marker, in ovariectomized females subcutaneously implanted with a pellet containing a diestrus-like level of estradiol. In addition, undernutrition completely blocked the estradiol-induced LH surge and diminished Kiss1 messenger RNA abundance, without decreasing estradiol receptor α (Erα), in micropunches of the AVPV. Collectively, these studies demonstrate that undernutrition disrupts ovarian cyclicity in females via impairment both of ARCKiss1 control of LH pulses and AVPVKiss1 induction of the LH surge.
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Affiliation(s)
- Michael J Kreisman
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, California 92093-0674, USA
| | - Kirollos S Tadrousse
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, California 92093-0674, USA
| | - Richard B McCosh
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, California 92093-0674, USA
| | - Kellie M Breen
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, California 92093-0674, USA
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9
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Nair BB, Khant Aung Z, Porteous R, Prescott M, Glendining KA, Jenkins DE, Augustine RA, Silva MSB, Yip SH, Bouwer GT, Brown CH, Jasoni CL, Campbell RE, Bunn SJ, Anderson GM, Grattan DR, Herbison AE, Iremonger KJ. Impact of chronic variable stress on neuroendocrine hypothalamus and pituitary in male and female C57BL/6J mice. J Neuroendocrinol 2021; 33:e12972. [PMID: 33896057 DOI: 10.1111/jne.12972] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 03/02/2021] [Accepted: 03/24/2021] [Indexed: 12/18/2022]
Abstract
Chronic stress exerts multiple negative effects on the physiology and health of an individual. In the present study, we examined hypothalamic, pituitary and endocrine responses to 14 days of chronic variable stress (CVS) in male and female C57BL/6J mice. In both sexes, CVS induced a significant decrease in body weight and enhanced the acute corticosterone stress response, which was accompanied by a reduction in thymus weight only in females. However, single-point blood measurements of basal prolactin, thyroid-stimulating hormone, luteinising hormone, growth hormone and corticosterone levels taken at the end of the CVS were not different from those of controls. Similarly, pituitary mRNA expression of Fshb, Lhb, Prl and Gh was unchanged by CVS, although Pomc and Tsh were significantly elevated. Within the adrenal medulla, mRNA for Th, Vip and Gal were elevated following CVS. Avp transcript levels within the paraventricular nucleus of the hypothalamus were increased by CVS; however, levels of Gnrh1, Crh, Oxt, Sst, Trh, Ghrh, Th and Kiss1 remained unchanged. Oestrous cycles were lengthened slightly by CVS and ovarian histology revealed a reduction in the number of preovulatory follicles and corpora lutea. Taken together, these observations indicate that 14 days of CVS induces an up-regulation of the neuroendocrine stress axis and creates a mild disruption of female reproductive function. However, the lack of changes in other neuroendocrine axes controlling anterior and posterior pituitary secretion suggest that most neuroendocrine axes are relatively resilient to CVS.
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Affiliation(s)
- Betina B Nair
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Zin Khant Aung
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Robert Porteous
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Melanie Prescott
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Kelly A Glendining
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Danielle E Jenkins
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Rachael A Augustine
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Mauro S B Silva
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Siew H Yip
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Gregory T Bouwer
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Colin H Brown
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Christine L Jasoni
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Rebecca E Campbell
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Stephen J Bunn
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Greg M Anderson
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - David R Grattan
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Allan E Herbison
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
| | - Karl J Iremonger
- Centre for Neuroendocrinology, Departments of Anatomy and Physiology, University of Otago, Dunedin, New Zealand
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10
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Yip SH, Liu X, Hessler S, Cheong I, Porteous R, Herbison AE. Indirect Suppression of Pulsatile LH Secretion by CRH Neurons in the Female Mouse. Endocrinology 2021; 162:6128702. [PMID: 33543235 DOI: 10.1210/endocr/bqaa237] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Indexed: 01/01/2023]
Abstract
Acute stress is a potent suppressor of pulsatile luteinizing hormone (LH) secretion, but the mechanisms through which corticotrophin-releasing hormone (CRH) neurons inhibit gonadotropin-releasing hormone (GnRH) release remain unclear. The activation of paraventricular nucleus (PVN) CRH neurons with Cre-dependent hM3Dq in Crh-Cre female mice resulted in the robust suppression of pulsatile LH secretion. Channelrhodopsin (ChR2)-assisted circuit mapping revealed that PVN CRH neuron projections existed around kisspeptin neurons in the arcuate nucleus (ARN) although many more fibers made close appositions with GnRH neuron distal dendrons in the ventral ARN. Acutely prepared brain slice electrophysiology experiments in GnRH- green fluorescent protein (GFP) mice showed a dose-dependent (30 and 300 nM CRH) activation of firing in ~20% of GnRH neurons in both intact diestrus and ovariectomized mice with inhibitory effects being uncommon (<8%). Confocal GCaMP6 imaging of GnRH neuron distal dendrons in acute para-horizontal brain slices from GnRH-Cre mice injected with Cre-dependent GCaMP6s adeno-associated viruses demonstrated no effects of 30 to 300 nM CRH on GnRH neuron dendron calcium concentrations. Electrophysiological recordings of ARN kisspeptin neurons in Crh-Cre,Kiss1-GFP mice revealed no effects of 30 -300 nM CRH on basal or neurokinin B-stimulated firing rate. Similarly, the optogenetic activation (2-20 Hz) of CRH nerve terminals in the ARN of Crh-Cre,Kiss1-GFP mice injected with Cre-dependent ChR2 had no effect on kisspeptin neuron firing. Together, these studies demonstrate that PVN CRH neurons potently suppress LH pulsatility but do not exert direct inhibitory control over GnRH neurons, at their cell body or dendron, or the ARN kisspeptin neuron pulse generator in the female mouse.
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Affiliation(s)
- Siew Hoong Yip
- Centre for Neuroendocrinology and Department of Physiology, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
| | - Xinhuai Liu
- Centre for Neuroendocrinology and Department of Physiology, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
| | - Sabine Hessler
- Centre for Neuroendocrinology and Department of Physiology, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
| | - Isaiah Cheong
- Centre for Neuroendocrinology and Department of Physiology, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
| | - Robert Porteous
- Centre for Neuroendocrinology and Department of Physiology, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
| | - Allan E Herbison
- Centre for Neuroendocrinology and Department of Physiology, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
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