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Manoogian ENC, Bahiru MS, Wang EJ, Holder M, Bittman EL. Neuroendocrine effects of the duper mutation in Syrian hamsters: a role for Cryptochrome 1. Front Physiol 2024; 15:1351682. [PMID: 38444761 PMCID: PMC10912188 DOI: 10.3389/fphys.2024.1351682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 01/31/2024] [Indexed: 03/07/2024] Open
Abstract
Molecular and physiological determinants of the timing of reproductive events, including the pre-ovulatory LH surge and seasonal fluctuations in fertility, are incompletely understood. We used the Cryptochrome 1-deficient duper mutant to examine the role of this core circadian clock gene in Syrian hamsters. We find that the phase of the LH surge and its stability upon shifts of the light: dark cycle are altered in duper mutants. The intensity of immunoreactive PER1 in GnRH cells of the preoptic area peaks earlier in the day in duper than wild type hamsters. We note that GnRH fibers coursing through the suprachiasmatic nucleus (SCN) contact vasopressin- and VIP-immunoreactive cells, suggesting a possible locus of circadian control of the LH surge. Unlike wild types, duper hamsters do not regress their gonads within 8 weeks of constant darkness, despite evidence of melatonin secretion during the subjective night. In light of the finding that the duper allele is a stop codon in Cryptochrome 1, our results suggest important neuroendocrine functions of this core circadian clock gene.
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Affiliation(s)
| | | | | | | | - Eric L. Bittman
- Department of Biology and Program in Neuroscience, University of Massachusetts, Amherst, MA, United States
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2
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Boyd HM, Frick KM, Kwapis JL. Connecting the Dots: Potential Interactions Between Sex Hormones and the Circadian System During Memory Consolidation. J Biol Rhythms 2023; 38:537-555. [PMID: 37464775 PMCID: PMC10615791 DOI: 10.1177/07487304231184761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Both the circadian clock and sex hormone signaling can strongly influence brain function, yet little is known about how these 2 powerful modulatory systems might interact during complex neural processes like memory consolidation. Individually, the molecular components and action of each of these systems have been fairly well-characterized, but there is a fundamental lack of information about how these systems cooperate. In the circadian system, clock genes function as timekeeping molecules that convey time-of-day information on a well-stereotyped cycle that is governed by the suprachiasmatic nucleus. Keeping time is particularly important to synchronize various physiological processes across the brain and body, including those that regulate memory consolidation. Similarly, sex hormones are powerful modulators of memory, with androgens, estrogens, and progestins, all influencing memory consolidation within memory-relevant brain regions like the hippocampus. Despite clear evidence that each system can influence memory individually, exactly how the circadian and hormonal systems might interact to impact memory consolidation remains unclear. Research investigating either sex hormone action or circadian gene function within memory-relevant brain regions has unveiled several notable places in which the two systems could interact to control memory. Here, we bring attention to known interactions between the circadian clock and sex hormone signaling. We then review sex hormone-mediated control of memory consolidation, highlighting potential nodes through which the circadian system might interact during memory formation. We suggest that the bidirectional relationship between these two systems is essential for proper control of memory formation based on an animal's hormonal and circadian state.
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Affiliation(s)
- Hannah M. Boyd
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, Pennsylvania
| | - Karyn M. Frick
- Department of Psychology, University of Wisconsin–Milwaukee, Milwaukee, Wisconsin
| | - Janine L. Kwapis
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, Pennsylvania
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3
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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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Starrett JR, Moenter SM. Hypothalamic kisspeptin neurons as potential mediators of estradiol negative and positive feedback. Peptides 2023; 163:170963. [PMID: 36740189 PMCID: PMC10516609 DOI: 10.1016/j.peptides.2023.170963] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/09/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023]
Abstract
Gonadal steroid feedback regulates the brain's patterned secretion of gonadotropin-releasing hormone (GnRH). Negative feedback, which occurs in males and during the majority of the female cycle, modulates the amplitude and frequency of GnRH pulses. Positive feedback occurs in females when high estradiol induces a surge pattern of GnRH release. These two forms of feedback and their corresponding patterns of GnRH secretion are thought to be mediated by kisspeptin-expressing neurons in two hypothalamic areas: the arcuate nucleus and the anteroventral periventricular area. In this review, we present evidence for this theory and remaining questions to be addressed.
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Affiliation(s)
- J Rudolph Starrett
- Departments of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Suzanne M Moenter
- Departments of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA; Obstetrics & Gynecology, University of Michigan, Ann Arbor, MI 48109, USA; The Reproductive Sciences Program, University of Michigan, Ann Arbor, MI 48109, USA.
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5
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Piet R. Circadian and kisspeptin regulation of the preovulatory surge. Peptides 2023; 163:170981. [PMID: 36842628 DOI: 10.1016/j.peptides.2023.170981] [Citation(s) in RCA: 6] [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: 11/30/2022] [Revised: 02/19/2023] [Accepted: 02/23/2023] [Indexed: 02/28/2023]
Abstract
Fertility in mammals is ultimately controlled by a small population of neurons - the gonadotropin-releasing hormone (GnRH) neurons - located in the ventral forebrain. GnRH neurons control gonadal function through the release of GnRH, which in turn stimulates the secretion of the anterior pituitary gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In spontaneous ovulators, ovarian follicle maturation eventually stimulates, via sex steroid feedback, the mid-cycle surge in GnRH and LH secretion that causes ovulation. The GnRH/LH surge is initiated in many species just before the onset of activity through processes controlled by the central circadian clock, ensuring that the neuroendocrine control of ovulation and sex behavior are coordinated. This review aims to give an overview of anatomical and functional studies that collectively reveal some of the mechanisms through which the central circadian clock regulates GnRH neurons and their afferent circuits to drive the preovulatory surge.
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Affiliation(s)
- Richard Piet
- Brain Health Research Institute and Department of Biological Sciences, Kent State University, Kent, OH, United States.
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6
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Starnes AN, Jones JR. Inputs and Outputs of the Mammalian Circadian Clock. BIOLOGY 2023; 12:biology12040508. [PMID: 37106709 PMCID: PMC10136320 DOI: 10.3390/biology12040508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023]
Abstract
Circadian rhythms in mammals are coordinated by the central circadian pacemaker, the suprachiasmatic nucleus (SCN). Light and other environmental inputs change the timing of the SCN neural network oscillator, which, in turn, sends output signals that entrain daily behavioral and physiological rhythms. While much is known about the molecular, neuronal, and network properties of the SCN itself, the circuits linking the outside world to the SCN and the SCN to rhythmic outputs are understudied. In this article, we review our current understanding of the synaptic and non-synaptic inputs onto and outputs from the SCN. We propose that a more complete description of SCN connectivity is needed to better explain how rhythms in nearly all behaviors and physiological processes are generated and to determine how, mechanistically, these rhythms are disrupted by disease or lifestyle.
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7
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Moeller JS, Bever SR, Finn SL, Phumsatitpong C, Browne MF, Kriegsfeld LJ. Circadian Regulation of Hormonal Timing and the Pathophysiology of Circadian Dysregulation. Compr Physiol 2022; 12:4185-4214. [PMID: 36073751 DOI: 10.1002/cphy.c220018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Circadian rhythms are endogenously generated, daily patterns of behavior and physiology that are essential for optimal health and disease prevention. Disruptions to circadian timing are associated with a host of maladies, including metabolic disease and obesity, diabetes, heart disease, cancer, and mental health disturbances. The circadian timing system is hierarchically organized, with a master circadian clock located in the suprachiasmatic nucleus (SCN) of the anterior hypothalamus and subordinate clocks throughout the CNS and periphery. The SCN receives light information via a direct retinal pathway, synchronizing the master clock to environmental time. At the cellular level, circadian rhythms are ubiquitous, with rhythms generated by interlocking, autoregulatory transcription-translation feedback loops. At the level of the SCN, tight cellular coupling maintains rhythms even in the absence of environmental input. The SCN, in turn, communicates timing information via the autonomic nervous system and hormonal signaling. This signaling couples individual cellular oscillators at the tissue level in extra-SCN brain loci and the periphery and synchronizes subordinate clocks to external time. In the modern world, circadian disruption is widespread due to limited exposure to sunlight during the day, exposure to artificial light at night, and widespread use of light-emitting electronic devices, likely contributing to an increase in the prevalence, and the progression, of a host of disease states. The present overview focuses on the circadian control of endocrine secretions, the significance of rhythms within key endocrine axes for typical, homeostatic functioning, and implications for health and disease when dysregulated. © 2022 American Physiological Society. Compr Physiol 12: 1-30, 2022.
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Affiliation(s)
- Jacob S Moeller
- Graduate Group in Endocrinology, University of California, Berkeley, California, USA
| | - Savannah R Bever
- Department of Psychology, University of California, Berkeley, California, USA
| | - Samantha L Finn
- Department of Psychology, University of California, Berkeley, California, USA
| | | | - Madison F Browne
- Department of Psychology, University of California, Berkeley, California, USA
| | - Lance J Kriegsfeld
- Graduate Group in Endocrinology, University of California, Berkeley, California, USA.,Department of Psychology, University of California, Berkeley, California, USA.,Department of Integrative Biology, University of California, Berkeley, California, USA.,The Helen Wills Neuroscience Institute, University of California, Berkeley, California, USA
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8
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Tonsfeldt KJ, Cui LJ, Lee J, Walbeek TJ, Brusman LE, Jin Y, Mieda M, Gorman MR, Mellon PL. Female fertility does not require Bmal1 in suprachiasmatic nucleus neurons expressing arginine vasopressin, vasoactive intestinal peptide, or neuromedin-S. Front Endocrinol (Lausanne) 2022; 13:956169. [PMID: 35992114 PMCID: PMC9389073 DOI: 10.3389/fendo.2022.956169] [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: 05/30/2022] [Accepted: 07/06/2022] [Indexed: 01/27/2023] Open
Abstract
Disruptions to the circadian system alter reproductive capacity, particularly in females. Mice lacking the core circadian clock gene, Bmal1, are infertile and have evidence of neuroendocrine disruption including the absence of the preovulatory luteinizing hormone (LH) surge and enhanced responsiveness to exogenous kisspeptin. Here, we explore the role of Bmal1 in suprachiasmatic nucleus (SCN) neuron populations known to project to the neuroendocrine axis. We generated four mouse lines using Cre/Lox technology to create conditional deletion of Bmal1 in arginine vasopressin (Bmal1fl/fl:Avpcre ), vasoactive intestinal peptide (Bmal1fl/fl:Vipcre ), both (Bmal1fl/fl:Avpcre+Vipcre ), and neuromedin-s (Bmal1fl/fl:Nmscre ) neurons. We demonstrate that the loss of Bmal1 in these populations has substantial effects on home-cage circadian activity and temperature rhythms. Despite this, we found that female mice from these lines demonstrated normal estrus cycles, fecundity, kisspeptin responsiveness, and inducible LH surge. We found no evidence of reproductive disruption in constant darkness. Overall, our results indicate that while conditional Bmal1 knockout in AVP, VIP, or NMS neurons is sufficient to disrupted locomotor activity, this disruption is insufficient to recapitulate the neuroendocrine reproductive effects of the whole-body Bmal1 knockout.
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Affiliation(s)
- Karen J. Tonsfeldt
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
| | - Laura J. Cui
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Jinkwon Lee
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Thijs J. Walbeek
- Department of Psychology, University of California, San Diego, La Jolla, CA, United States
| | - Liza E. Brusman
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Ye Jin
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Michihiro Mieda
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Michael R. Gorman
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
- Department of Psychology, University of California, San Diego, La Jolla, CA, United States
| | - Pamela L. Mellon
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
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9
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Kauffman AS. Neuroendocrine mechanisms underlying estrogen positive feedback and the LH surge. Front Neurosci 2022; 16:953252. [PMID: 35968365 PMCID: PMC9364933 DOI: 10.3389/fnins.2022.953252] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 07/08/2022] [Indexed: 01/26/2023] Open
Abstract
A fundamental principle in reproductive neuroendocrinology is sex steroid feedback: steroid hormones secreted by the gonads circulate back to the brain to regulate the neural circuits governing the reproductive neuroendocrine axis. These regulatory feedback loops ultimately act to modulate gonadotropin-releasing hormone (GnRH) secretion, thereby affecting gonadotropin secretion from the anterior pituitary. In females, rising estradiol (E2) during the middle of the menstrual (or estrous) cycle paradoxically "switch" from being inhibitory on GnRH secretion ("negative feedback") to stimulating GnRH release ("positive feedback"), resulting in a surge in GnRH secretion and a downstream LH surge that triggers ovulation. While upstream neural afferents of GnRH neurons, including kisspeptin neurons in the rostral hypothalamus, are proposed as critical loci of E2 feedback action, the underlying mechanisms governing the shift between E2 negative and positive feedback are still poorly understood. Indeed, the precise cell targets, neural signaling factors and receptors, hormonal pathways, and molecular mechanisms by which ovarian-derived E2 indirectly stimulates GnRH surge secretion remain incompletely known. In many species, there is also a circadian component to the LH surge, restricting its occurrence to specific times of day, but how the circadian clock interacts with endocrine signals to ultimately time LH surge generation also remains a major gap in knowledge. Here, we focus on classic and recent data from rodent models and discuss the consensus knowledge of the neural players, including kisspeptin, the suprachiasmatic nucleus, and glia, as well as endocrine players, including estradiol and progesterone, in the complex regulation and generation of E2-induced LH surges in females.
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10
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Jamieson BB, Piet R. Kisspeptin neuron electrophysiology: Intrinsic properties, hormonal modulation, and regulation of homeostatic circuits. Front Neuroendocrinol 2022; 66:101006. [PMID: 35640722 DOI: 10.1016/j.yfrne.2022.101006] [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: 12/30/2021] [Revised: 05/05/2022] [Accepted: 05/19/2022] [Indexed: 11/04/2022]
Abstract
The obligatory role of kisspeptin (KISS1) and its receptor (KISS1R) in regulating the hypothalamic-pituitary-gonadal axis, puberty and fertility was uncovered in 2003. In the few years that followed, an impressive body of work undertaken in many species established that neurons producing kisspeptin orchestrate gonadotropin-releasing hormone (GnRH) neuron activity and subsequent GnRH and gonadotropin hormone secretory patterns, through kisspeptin-KISS1R signaling, and mediate many aspects of gonadal steroid hormone feedback regulation of GnRH neurons. Here, we review knowledge accrued over the past decade, mainly in genetically modified mouse models, of the electrophysiological properties of kisspeptin neurons and their regulation by hormonal feedback. We also discuss recent progress in our understanding of the role of these cells within neuronal circuits that control GnRH neuron activity and GnRH secretion, energy balance and, potentially, other homeostatic and reproductive functions.
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Affiliation(s)
| | - Richard Piet
- Brain Health Research Institute and Department of Biological Sciences, Kent State University, Kent, OH, USA.
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11
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Moralia MA, Quignon C, Simonneaux M, Simonneaux V. Environmental disruption of reproductive rhythms. Front Neuroendocrinol 2022; 66:100990. [PMID: 35227765 DOI: 10.1016/j.yfrne.2022.100990] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/06/2022] [Accepted: 02/21/2022] [Indexed: 12/17/2022]
Abstract
Reproduction is a key biological function requiring a precise synchronization with annual and daily cues to cope with environmental fluctuations. Therefore, humans and animals have developed well-conserved photoneuroendocrine pathways to integrate and process daily and seasonal light signals within the hypothalamic-pituitary-gonadal axis. However, in the past century, industrialization and the modern 24/7 human lifestyle have imposed detrimental changes in natural habitats and rhythms of life. Indeed, exposure to an excessive amount of artificial light at inappropriate timing because of shift work and nocturnal urban lighting, as well as the ubiquitous environmental contamination by endocrine-disrupting chemicals, threaten the integrity of the daily and seasonal timing of biological functions. Here, we review recent epidemiological, field and experimental studies to discuss how light and chemical pollution of the environment can disrupt reproductive rhythms by interfering with the photoneuroendocrine timing system.
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Affiliation(s)
- Marie-Azélie Moralia
- Université de Strasbourg, Centre National de la Recherche Scientifique, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Clarisse Quignon
- Université de Strasbourg, Centre National de la Recherche Scientifique, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Marine Simonneaux
- Université de Strasbourg, Centre National de la Recherche Scientifique, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Valérie Simonneaux
- Université de Strasbourg, Centre National de la Recherche Scientifique, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France.
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12
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Singh P, Anjum S, Srivastava RK, Tsutsui K, Krishna A. Central and peripheral neuropeptide RFRP-3: A bridge linking reproduction, nutrition, and stress response. Front Neuroendocrinol 2022; 65:100979. [PMID: 35122778 DOI: 10.1016/j.yfrne.2022.100979] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/30/2021] [Accepted: 01/06/2022] [Indexed: 02/06/2023]
Abstract
This article is an amalgamation of the current status of RFRP-3 (GnIH) in reproduction and its association with the nutrition and stress-mediated changes in the reproductive activities. GnIH has been demonstrated in the hypothalamus of all the vertebrates studied so far and is a well-known inhibitor of GnRH mediated reproduction. The RFRP-3 neurons interact with the other hypothalamic neurons and the hormonal signals from peripheral organs for coordinating the nutritional, stress, and environmental associated changes to regulate reproduction. RFRP-3 has also been shown to regulate puberty, reproductive cyclicity and senescence depending upon the nutritional status. A favourable nutritional status and the environmental cues which are permissive for the successful breeding and pregnancy outcome keep RFRP-3 level low, whereas unfavourable nutritional status and stressful conditions increase the expression of RFRP-3 which impairs the reproduction. Still our knowledge about RFRP-3 is incomplete regarding its therapeutic application for nutritional or stress-related reproductive disorders.
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Affiliation(s)
- Padmasana Singh
- Department of Zoology, Indira Gandhi National Tribal University, Amarkantak, Anuppur 484886, MP, India
| | - Shabana Anjum
- Department of Chemical Engineering, American University of Sharjah, Sharjah 26666, United Arab Emirates
| | - Raj Kamal Srivastava
- Department of Zoology, Indira Gandhi National Tribal University, Amarkantak, Anuppur 484886, MP, India
| | - Kazuyoshi Tsutsui
- Department of Biology and Center for Medical Life Science, Waseda University, Kagamiyama 1-7-1, Higashi-Hiroshima University 739-8521, Japan
| | - Amitabh Krishna
- Department of Zoology, Banaras Hindu University, Varanasi 221005, UP, India.
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13
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Angelopoulou E, Kalsbeek A, Simonneaux V. Age-dependent change of RFRP-3 neuron numbers and innervation in female mice. Neuropeptides 2022; 92:102224. [PMID: 34998113 DOI: 10.1016/j.npep.2021.102224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 12/22/2021] [Accepted: 12/25/2021] [Indexed: 11/28/2022]
Abstract
In female mammals, reproductive senescence is a complex process involving progressive ovarian dysfunction, associated with altered central control of the hypothalamic-pituitary-gonadal axis and desynchronization of the circadian system. The objective of this study was to investigate age-dependent changes in the daily regulation of Arg-Phe amide-related peptide-3 (RFRP-3), a hypothalamic peptide involved in reproduction, in female C57BL/6 J mice of different age groups (4, 13, and 19 months old) sampled at their diestrus stage. We found an age-dependent decrease in the total number of RFRP-3 neurons and in the relative number of activated (i.e. c-Fos-positive) RFRP-3 neurons. RFRP-3 neuronal activation exhibited a daily variation in young and middle-aged mice, which was abolished in 19-month-old mice. We also found a daily variation in the number of RFRP-3 neurons receiving close vasopressin (AVP)- and vasoactive intestinal peptide (VIP)-ergic fiber appositions in mice aged 4 and 13 months, but not in 19-month-old mice. However, we found no daily or age-dependent changes in the AVP and VIP fiber density in the dorsomedial hypothalamus. Plasma LH levels were similar in mice aged 4 and 13 months, but were markedly increased in 19-month-old mice. The present findings indicate that the number of RFRP-3 positive neurons is downregulated during old age and that the daily changes in their innervation by the circadian peptides AVP and VIP are abolished. This age-associated reduced (rhythmic) activity of the inhibitory RFRP-3 system could be implicated in the elevated LH secretion observed during reproductive senescence.
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Affiliation(s)
- Eleni Angelopoulou
- Institut des Neurosciences Cellulaire et Intégratives (UPR CNRS3212), Université de Strasbourg, 8, allée du Général Rouvillois, 67000 Strasbourg, France; Netherlands Institute for Neuroscience (NIN), Amsterdam, the Netherlands; Laboratory of Endocrinology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, the Netherlands
| | - Andries Kalsbeek
- Netherlands Institute for Neuroscience (NIN), Amsterdam, the Netherlands; Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands; Laboratory of Endocrinology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, the Netherlands
| | - Valérie Simonneaux
- Institut des Neurosciences Cellulaire et Intégratives (UPR CNRS3212), Université de Strasbourg, 8, allée du Général Rouvillois, 67000 Strasbourg, France.
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14
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Ikegami K, Kajihara S, Umatani C, Nakajo M, Kanda S, Oka Y. Estrogen upregulates the firing activity of hypothalamic gonadotropin-releasing hormone (GnRH1) neurons in the evening in female medaka. J Neuroendocrinol 2022; 34:e13101. [PMID: 35132714 DOI: 10.1111/jne.13101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 12/23/2021] [Accepted: 01/18/2022] [Indexed: 11/27/2022]
Abstract
The reproductive function of vertebrates is regulated by the hypothalamic-pituitary-gonadal axis. In sexually mature females, gonadotropin-releasing hormone (GnRH) neurons in the preoptic area (POA) are assumed to be responsible for a cyclic large increase in GnRH release, the GnRH surge, triggering a luteinizing hormone (LH) surge, which leads to ovulation. Precise temporal regulation of the preovulatory GnRH/LH surge is important for successful reproduction because ovulation should occur after follicular development. The time course of the circulating level of estrogen is correlated with the ovulatory cycle throughout vertebrates. However, the neural mechanisms underlying estrogen-induced preovulatory GnRH surge after folliculogenesis still remain unclear, especially in non-mammals. Here, we used a versatile non-mammalian model medaka for the analysis of the involvement of estrogen in the regulation of POA-GnRH (GnRH1) neurons. Electrophysiological analysis using a whole brain-pituitary in vitro preparation, which maintains the hypophysiotropic function of GnRH1 neurons intact, revealed that 17β-estradiol (E2 ) administration recovers the ovariectomy-induced lowered GnRH1 neuronal activity in the evening, indicating the importance of E2 for upregulation of GnRH1 neuronal activity. The importance of E2 was also confirmed by the fact that GnRH1 neuronal activity was low in short-day photoperiod-conditioned females (low E2 model). However, E2 failed to upregulate the firing activity of GnRH1 neurons in the morning, suggesting the involvement of additional time-of-day signal(s) for triggering GnRH/LH surges at an appropriate timing. We also provide morphological evidence for the localization of estrogen receptor subtypes in GnRH1 neurons. In conclusion, we propose a working hypothesis in which both estrogenic and time-of-day signals act in concert to timely upregulate the firing activity of GnRH1 neurons that trigger the GnRH surge at an appropriate timing in a female-specific manner. This neuroendocrinological mechanism is suggested to be responsible for the generation of ovulatory cycles in female teleosts in general.
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Affiliation(s)
- Kana Ikegami
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Sho Kajihara
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Chie Umatani
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Mikoto Nakajo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Shinji Kanda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | - Yoshitaka Oka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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15
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Mansano NDS, Paradela RS, Bohlen TM, Zanardi IM, Chaves FM, Silveira MA, Tavares MR, Donato J, Frazao R. Vasoactive intestinal peptide exerts an excitatory effect on hypothalamic kisspeptin neurons during estrogen negative feedback. Mol Cell Endocrinol 2022; 542:111532. [PMID: 34915098 DOI: 10.1016/j.mce.2021.111532] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 12/30/2022]
Abstract
Hypothalamic kisspeptin neurons are the primary modulators of gonadotropin-releasing hormone (GnRH) neurons. It has been shown that circadian rhythms driven by the suprachiasmatic nucleus (SCN) contribute to GnRH secretion. Kisspeptin neurons are potential targets of SCN neurons due to reciprocal connections with the anteroventral periventricular and rostral periventricular nuclei (AVPV/PeN) and the arcuate nucleus of the hypothalamus (ARH). Vasoactive intestinal peptide (VIP), a notable SCN neurotransmitter, modulates GnRH secretion depending on serum estradiol levels, aging or time of the day. Considering that kisspeptin neurons may act as interneurons and mediate VIP's effects on the reproductive axis, we investigated the effects of VIP on hypothalamic kisspeptin neurons in female mice during estrogen negative feedback. Our findings indicate that VIP induces a TTX-independent depolarization of approximately 30% of AVPV/PeN kisspeptin neurons in gonad-intact (diestrus) and ovariectomized (OVX) mice. In the ARH, the percentage of kisspeptin neurons that were depolarized by VIP was even higher (approximately 90%). An intracerebroventricular infusion of VIP leds to an increased percentage of kisspeptin neurons expressing the phosphoSer133 cAMP-response-element-binding protein (pCREB) in the AVPV/PeN. On the other hand, pCREB expression in ARH kisspeptin neurons was similar between saline- and VIP-injected mice. Thus, VIP can recruit different signaling pathways to modulate AVPV/PeN or ARH kisspeptin neurons, resulting in distinct cellular responses. The expression of VIP receptors (VPACR) was upregulated in the AVPV/PeN, but not in the ARH, of OVX mice compared to mice on diestrus and estradiol-primed OVX mice. Our findings indicate that VIP directly influences distinct cellular aspects of the AVPV/PeN and ARH kisspeptin neurons during estrogen negative feedback, possibly to influence pulsatile LH secretion.
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Affiliation(s)
- Naira da Silva Mansano
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Regina Silva Paradela
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Tabata M Bohlen
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Izabela M Zanardi
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Fernanda Machado Chaves
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Marina Augusto Silveira
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Mariana Rosolen Tavares
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Renata Frazao
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
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16
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Tonsfeldt KJ, Mellon PL, Hoffmann HM. Circadian Rhythms in the Neuronal Network Timing the Luteinizing Hormone Surge. Endocrinology 2022; 163:6490154. [PMID: 34967900 PMCID: PMC8782605 DOI: 10.1210/endocr/bqab268] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Indexed: 01/01/2023]
Abstract
For billions of years before electric light was invented, life on Earth evolved under the pattern of light during the day and darkness during the night. Through evolution, nearly all organisms internalized the temporal rhythm of Earth's 24-hour rotation and evolved self-sustaining biological clocks with a ~24-hour rhythm. These internal rhythms are called circadian rhythms, and the molecular constituents that generate them are called molecular circadian clocks. Alignment of molecular clocks with the environmental light-dark rhythms optimizes physiology and behavior. This phenomenon is particularly true for reproductive function, in which seasonal breeders use day length information to time yearly changes in fertility. However, it is becoming increasingly clear that light-induced disruption of circadian rhythms can negatively impact fertility in nonseasonal breeders as well. In particular, the luteinizing hormone surge promoting ovulation is sensitive to circadian disruption. In this review, we will summarize our current understanding of the neuronal networks that underlie circadian rhythms and the luteinizing hormone surge.
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Affiliation(s)
- Karen J Tonsfeldt
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Pamela L Mellon
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
- Correspondence: Pamela L. Mellon, Ph.D., University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA 92093-0674.
| | - Hanne M Hoffmann
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, 766 Service Road, East Lansing, MI, 48824, USA
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17
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Ogawa S, Parhar IS. Heterogeneity in GnRH and kisspeptin neurons and their significance in vertebrate reproductive biology. Front Neuroendocrinol 2022; 64:100963. [PMID: 34798082 DOI: 10.1016/j.yfrne.2021.100963] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/11/2021] [Accepted: 10/31/2021] [Indexed: 02/07/2023]
Abstract
Vertebrate reproduction is essentially controlled by the hypothalamus-pituitary-gonadal (HPG) axis, which is a central dogma of reproductive biology. Two major hypothalamic neuroendocrine cell groups containing gonadotropin-releasing hormone (GnRH) and kisspeptin are crucial for control of the HPG axis in vertebrates. GnRH and kisspeptin neurons exhibit high levels of heterogeneity including their cellular morphology, biochemistry, neurophysiology and functions. However, the molecular foundation underlying heterogeneities in GnRH and kisspeptin neurons remains unknown. More importantly, the biological and physiological significance of their heterogeneity in reproductive biology is poorly understood. In this review, we first describe the recent advances in the neuroendocrine functions of kisspeptin-GnRH pathways. We then view the recent emerging progress in the heterogeneity of GnRH and kisspeptin neurons using morphological and single-cell transcriptomic analyses. Finally, we discuss our views on the significance of functional heterogeneity of reproductive endocrine cells and their potential relevance to reproductive health.
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Affiliation(s)
- Satoshi Ogawa
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia
| | - Ishwar S Parhar
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia.
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18
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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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19
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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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20
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Hoffmann HM, Meadows JD, Breuer JA, Yaw AM, Nguyen D, Tonsfeldt KJ, Chin AY, Devries BM, Trang C, Oosterhouse HJ, Lee JS, Doser JW, Gorman MR, Welsh DK, Mellon PL. The transcription factors SIX3 and VAX1 are required for suprachiasmatic nucleus circadian output and fertility in female mice. J Neurosci Res 2021; 99:2625-2645. [PMID: 34212416 PMCID: PMC8577618 DOI: 10.1002/jnr.24864] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 05/10/2021] [Indexed: 12/12/2022]
Abstract
The homeodomain transcription factors sine oculis homeobox 3 (Six3) and ventral anterior homeobox 1 (Vax1) are required for brain development. Their expression in specific brain areas is maintained in adulthood, where their functions are poorly understood. To identify the roles of Six3 and Vax1 in neurons, we conditionally deleted each gene using Synapsincre , a promoter targeting maturing neurons, and generated Six3syn and Vax1syn mice. Six3syn and Vax1syn females, but not males, had reduced fertility, due to impairment of the luteinizing hormone (LH) surge driving ovulation. In nocturnal rodents, the LH surge requires a precise timing signal from the brain's circadian pacemaker, the suprachiasmatic nucleus (SCN), near the time of activity onset. Indeed, both Six3syn and Vax1syn females had impaired rhythmic SCN output, which was associated with weakened Period 2 molecular clock function in both Six3syn and Vax1syn mice. These impairments were associated with a reduction of the SCN neuropeptide vasoactive intestinal peptide in Vax1syn mice and a modest weakening of SCN timekeeping function in both Six3syn and Vax1syn mice. Changes in SCN function were associated with mistimed peak PER2::LUC expression in the SCN and pituitary in both Six3syn and Vax1syn females. Interestingly, Six3syn ovaries presented reduced sensitivity to LH, causing reduced ovulation during superovulation. In conclusion, we have identified novel roles of the homeodomain transcription factors SIX3 and VAX1 in neurons, where they are required for proper molecular circadian clock function, SCN rhythmic output, and female fertility.
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Affiliation(s)
- Hanne M. Hoffmann
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, USA
| | - Jason D. Meadows
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
| | - Joseph A. Breuer
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
| | - Alexandra M. Yaw
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, USA
| | - Duong Nguyen
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, USA
| | - Karen J. Tonsfeldt
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
| | - Austin Y. Chin
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
| | - Brooke M. Devries
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, USA
| | - Crystal Trang
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
| | - Haley J. Oosterhouse
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
| | - Jessica Sora Lee
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
| | - Jeffrey W. Doser
- CANR Statistical Consulting Center, Michigan State University, East Lansing, MI, USA
| | - Michael R. Gorman
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
- Department of Psychology, University of California, San Diego, La Jolla, CA, USA
| | - David K. Welsh
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
| | - Pamela L. Mellon
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, USA
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21
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Angelopoulou E, Kalsbeek A, Simonneaux V. WITHDRAWN: Age-dependent modulation of RFRP-3 neurons in female mice. Neuropeptides 2021; 88:102146. [PMID: 33940493 DOI: 10.1016/j.npep.2021.102146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/12/2021] [Indexed: 10/21/2022]
Abstract
This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error.
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Affiliation(s)
- Eleni Angelopoulou
- Insitut des Neurosciences Cellulaire et Intégratives (UPR CNRS3212), Université de Strasbourg, 8, Allée du Général Rouvillois, 67000, Strasbourg, France; Netherlands Institute for Neuroscience (NIN), Amsterdam, the Netherlands; Laboratory of Endocrinology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, the Netherlands
| | - Andries Kalsbeek
- Netherlands Institute for Neuroscience (NIN), Amsterdam, the Netherlands; Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands; Laboratory of Endocrinology, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, the Netherlands
| | - Valérie Simonneaux
- Insitut des Neurosciences Cellulaire et Intégratives (UPR CNRS3212), Université de Strasbourg, 8, Allée du Général Rouvillois, 67000, Strasbourg, France.
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22
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Wilheim T, Nagy K, Mohanraj M, Ziarniak K, Watanabe M, Sliwowska J, Kalló I. Expression of type one cannabinoid receptor in different subpopulation of kisspeptin neurons and kisspeptin afferents to GnRH neurons in female mice. Brain Struct Funct 2021; 226:2387-2399. [PMID: 34263407 PMCID: PMC8354884 DOI: 10.1007/s00429-021-02339-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 07/02/2021] [Indexed: 12/03/2022]
Abstract
The endocannabinoids have been shown to target the afferents of hypothalamic neurons via cannabinoid 1 receptor (CB1) and thereby to influence their excitability at various physiological and/or pathological processes. Kisspeptin (KP) neurons form afferents of multiple neuroendocrine cells and influence their activity via signaling through a variation of co-expressed classical neurotransmitters and neuropeptides. The differential potency of endocannabinoids to influence the release of classical transmitters or neuropeptides, and the ovarian cycle-dependent functioning of the endocannabinoid signaling in the gonadotropin-releasing hormone (GnRH) neurons initiated us to study whether (a) the different subpopulations of KP neurons express CB1 mRNAs, (b) the expression is influenced by estrogen, and (c) CB1-immunoreactivity is present in the KP afferents to GnRH neurons. The aim of the study was to investigate the site- and cell-specific expression of CB1 in female mice using multiple labeling in situ hybridization and immunofluorescent histochemical techniques. The results support that CB1 mRNAs are expressed by both the GABAergic and glutamatergic subpopulations of KP neurons, the receptor protein is detectable in two-thirds of the KP afferents to GnRH neurons, and the expression of CB1 mRNA shows an estrogen-dependency. The applied estrogen-treatment, known to induce proestrus, reduced the level of CB1 transcripts in the rostral periventricular area of the third ventricle and arcuate nucleus, and differently influenced its co-localization with vesicular GABA transporter or vesicular glutamate transporter-2 in KP neurons. This indicates a gonadal cycle-dependent role of endocannabinoid signaling in the neuronal circuits involving KP neurons.
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Affiliation(s)
- Tamás Wilheim
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, P.O. Box 67, Budapest, 1450, Hungary
- Department of Neuroscience, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest, Hungary
| | - Krisztina Nagy
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, P.O. Box 67, Budapest, 1450, Hungary
| | - Mahendravarman Mohanraj
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, P.O. Box 67, Budapest, 1450, Hungary
| | - Kamil Ziarniak
- Laboratory of Neurobiology, Department of Zoology, Poznan University of Life Sciences, Poznan, Poland
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo, 060-8638, Japan
| | - Joanna Sliwowska
- Laboratory of Neurobiology, Department of Zoology, Poznan University of Life Sciences, Poznan, Poland
| | - Imre Kalló
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, P.O. Box 67, Budapest, 1450, Hungary.
- Department of Neuroscience, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest, Hungary.
- Doctoral School of Neurosciences "János Szentágothai", Semmelweis University, Budapest, Hungary.
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23
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Buijs RM, Soto Tinoco EC, Hurtado Alvarado G, Escobar C. The circadian system: From clocks to physiology. HANDBOOK OF CLINICAL NEUROLOGY 2021; 179:233-247. [PMID: 34225965 DOI: 10.1016/b978-0-12-819975-6.00013-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The circadian system, composed of the central autonomous clock, the suprachiasmatic nucleus (SCN), and systems of the body that follow the signals of the SCN, continuously change the homeostatic set points of the body over the day-night cycle. Changes in the body's physiological state that do not agree with the time of the day feedback to the hypothalamus, and provide input to the SCN to adjust the condition, thus reaching another set point required by the changed conditions. This allows the adjustment of the set points to another level when environmental conditions change, which is thought to promote adaptation and survival. In fasting, the body temperature drops to a lower level only at the beginning of the sleep phase. Stressful conditions raise blood pressure relatively more during the active period than during the rest phase. Extensive, mostly reciprocal SCN interactions, with hypothalamic networks, induce these physiological adjustments by hormonal and autonomic control of the body's organs. More importantly, in addition to SCN's hormonal and autonomic influences, SCN induced behavior, such as rhythmic food intake, induces the oscillation of many genes in all tissues, including the so-called clock genes, which have an essential role as a transcriptional driving force for numerous cellular processes. Consequently, the light-dark cycle, the rhythm of the SCN, and the resulting rhythm in behavior need to be perfectly synchronized, especially where it involves synchronizing food intake with the activity phase. If these rhythms are not synchronous for extended periods of times, such as during shift work, light exposure at night, or frequent night eating, disease may develop. As such, our circadian system is a perfect illustration of how hypothalamic-driven processes depend on and interact with each other and need to be in seamless synchrony with the body's physiology.
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Affiliation(s)
- Ruud M Buijs
- Hypothalamic Integration Mechanisms Laboratory, Department of Cellular Biology and Physiology, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico.
| | - Eva C Soto Tinoco
- Hypothalamic Integration Mechanisms Laboratory, Department of Cellular Biology and Physiology, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
| | - Gabriela Hurtado Alvarado
- Hypothalamic Integration Mechanisms Laboratory, Department of Cellular Biology and Physiology, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
| | - Carolina Escobar
- Faculty of Medicine, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
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Buijs RM, Hurtado-Alvarado G, Soto-Tinoco E. Vasopressin: An output signal from the suprachiasmatic nucleus to prepare physiology and behaviour for the resting phase. J Neuroendocrinol 2021; 33:e12998. [PMID: 34189788 DOI: 10.1111/jne.12998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/24/2021] [Accepted: 05/31/2021] [Indexed: 01/18/2023]
Abstract
Vasopressin (VP) is an important hormone produced in the supraoptic (SON) and paraventricular nucleus (PVN) with antidiuretic and vasoconstrictor functions in the periphery. As one of the first discovered peptide hormones, VP was also shown to act as a neurotransmitter, where VP is produced and released under the influence of various stimuli. VP is one of the core signals via which the biological clock, the suprachiasmatic nucleus (SCN), imposes its rhythm on its target structures and its production and release is influenced by the rhythm of clock genes and the light/dark cycle. This is contrasted with VP production and release from the bed nucleus of the stria terminalis and the medial amygdala, which is influenced by gonadal hormones, as well as with VP originating from the PVN and SON, which is released in the neural lobe and central targets. The release of VP from the SCN signals the near arrival of the resting phase in rodents and prepares their physiology accordingly by down-modulating corticosterone secretion, the reproductive cycle and locomotor activity. All these circadian variables are regulated within very narrow boundaries at a specific time of the day, where day-to-day variation is less than 5% at any particular hour. However, the circadian peak values can be at least ten times higher than the circadian trough values, indicating the need for an elaborate feedback system to inform the SCN and other participating nuclei about the actual levels reached during the circadian cycle. In short, the interplay between SCN circadian output and peripheral feedback to the SCN is essential for the adequate organisation of all circadian rhythms in physiology and behaviour.
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Affiliation(s)
- Ruud M Buijs
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
| | - Gabriela Hurtado-Alvarado
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
| | - Eva Soto-Tinoco
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
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Jamieson BB, Bouwer GT, Campbell RE, Piet R. Estrous Cycle Plasticity in the Central Clock Output to Kisspeptin Neurons: Implications for the Preovulatory Surge. Endocrinology 2021; 162:6213415. [PMID: 33824970 DOI: 10.1210/endocr/bqab071] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Indexed: 11/19/2022]
Abstract
Coordination of ovulation and behavior is critical to reproductive success in many species. During the female estrous cycle, the preovulatory gonadotropin surge occurs when ovarian follicles reach maturity and, in rodents, it begins just before the daily onset of activity, ensuring that ovulation coincides with sex behavior. Timing of the surge relies on projections from the suprachiasmatic nucleus (SCN), the locus of the central circadian clock, to hypothalamic circuits that regulate gonadotropin secretion. The cellular mechanisms through which the SCN controls these circuits and gates the preovulatory surge to the appropriate estrous cycle stage, however, are poorly understood. We investigated in mice the functional impact of SCN arginine-vasopressin (AVP) neuron projections to kisspeptin (Kiss1) neurons in the rostral periventricular area of the third ventricle (RP3VKiss1), responsible for generating the preovulatory surge. Conditional anterograde tracing revealed that SCNAVP neurons innervate approximately half of the RP3VKiss1 neurons. Optogenetic activation of SCNAVP projections in brain slices caused an AVP-mediated stimulation of RP3VKiss1 action potential firing in proestrus, the cycle stage when the surge is generated. This effect was less prominent in diestrus, the preceding cycle stage, and absent in estrus, following ovulation. Remarkably, in estrus, activation of SCNAVP projections resulted in GABA-mediated inhibition of RP3VKiss1 neuron firing, an effect rarely encountered in other cycle stages. Together, these data reveal functional plasticity in SCNAVP neuron output that drives opposing effects on RP3VKiss1 neuron activity across the ovulatory cycle. This might contribute to gating activation of the preovulatory surge to the appropriate estrous cycle stage.
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Affiliation(s)
- Bradley B Jamieson
- Centre for Neuroendocrinology & Department of Physiology, University of Otago, Dunedin 9054, New Zealand
| | - Gregory T Bouwer
- Centre for Neuroendocrinology & Department of Physiology, University of Otago, Dunedin 9054, New Zealand
| | - Rebecca E Campbell
- Centre for Neuroendocrinology & Department of Physiology, University of Otago, Dunedin 9054, New Zealand
| | - Richard Piet
- Centre for Neuroendocrinology & Department of Physiology, University of Otago, Dunedin 9054, New Zealand
- Brain Health Research Institute & Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
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Alvord VM, Kantra EJ, Pendergast JS. Estrogens and the circadian system. Semin Cell Dev Biol 2021; 126:56-65. [PMID: 33975754 DOI: 10.1016/j.semcdb.2021.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 11/26/2022]
Abstract
Circadian rhythms are ~24 h cycles of behavior and physiology that are generated by a network of molecular clocks located in nearly every tissue in the body. In mammals, the circadian system is organized hierarchically such that the suprachiasmatic nucleus (SCN) is the main circadian clock that receives light information from the eye and entrains to the light-dark cycle. The SCN then coordinates the timing of tissue clocks so internal rhythms are aligned with environmental cycles. Estrogens interact with the circadian system to regulate biological processes. At the molecular level, estrogens and circadian genes interact to regulate gene expression and cell biology. Estrogens also regulate circadian behavior across the estrous cycle. The timing of ovulation during the estrous cycle requires coincident estrogen and SCN signals. Studies using circadian gene reporter mice have also elucidated estrogen regulation of peripheral tissue clocks and metabolic rhythms. This review synthesizes current understanding of the interplay between estrogens and the circadian system, with a focus on female rodents, in regulating molecular, physiological, and behavioral processes.
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Abstract
Female reproductive success relies on proper integration of circadian- and ovarian- signals to the hypothalamic-pituitary-gonadal axis in order to synchronize the preovulatory LH surge at the end of the ovarian follicular stage with the onset of the main active period. In this study, we used a combination of neuroanatomical and electrophysiological approaches to assess whether the hypothalamic neurons expressing Arg-Phe amide-related peptide (RFRP-3), a gonadotropin inhibitory peptide, exhibit daily and estrous stage dependent variations in female mice. Furthermore, we investigated whether arginine vasopressin (AVP), a circadian peptide produced by the suprachiamatic nucleus regulates RFRP-3 neurons. The number of c-Fos–positive RFRP-3 immunoreactive neurons is significantly reduced at the day-to-night transition with no difference between diestrus and proestrus. Contrastingly, RFRP neuron firing rate is higher in proestrus as compared to diestrus, independently of the time of the day. AVP immunoreactive fibers contact RFRP neurons with the highest density observed during the late afternoon of diestrus and proestrus. Application of AVP increases RFRP neurons firing in the afternoon (ZT6-10) of diestrus, but not at the same time point of proestrus, indicating that AVP signaling on RFRP neurons may depend on circulating ovarian steroids. Together, these studies show that RFRP neurons integrate both daily and estrogenic signals, which downstream may help to properly time the preovulatory LH surge.
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Zhang Y, Xu Y, Ding H, Yu W, Chen L. Prenatal exposure of female mice to perfluorononanoic acid delays pubertal activation of the reproductive endocrine axis through enhanced hepatic FGF21 production. CHEMOSPHERE 2021; 269:128776. [PMID: 33131727 DOI: 10.1016/j.chemosphere.2020.128776] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 10/20/2020] [Accepted: 10/25/2020] [Indexed: 06/11/2023]
Abstract
The developmental toxicity of perfluorononanoic acid (PFNA), a ubiquitous environmental contaminant, has been associated with the activation of PPARα. This study investigated influence of prenatal exposure to PFNA in pubertal activation of reproductive endocrine axis in female mice and explored underlying molecular mechanisms. Herein, we show that when PFNA (3 mg kg-1 body weight) was orally administered during gestational days 1-18, dams showed an increase in liver weight and hepatic FGF21 synthesis via PPARα activation, and their female offspring (PFNA mice) showed an increase in liver weight and hepatic FGF21 synthesis from postnatal day (PND) 1 to PND21, which were corrected by the administration of the PPARα antagonist GW6471 from PND1-14 (pup-GW). Expression of vasopressin (VAP) in the hypothalamic suprachiasmatic nucleus (SCN) was reduced in PND14-30 PFNA mice, and could be rescued by pup-GW. Pubertal activation of kisspeptin neurons in anteroventral periventricular nucleus (AVPV) and hypothalamic GnRH neurons in PND21-30 PFNA mice was obviously suppressed, but were recovered by pup-GW or PND21-30 application of VAP. The times of vaginal opening and first estrus were delayed in PFNA mice with a decrease in ovary size and the numbers of primary, secondary and antral follicles, and corpora lutea, which were relieved by pup-GW or application of VAP. The findings indicate that prenatal exposure to PFNA through increased FGF21 production in postnatal female offspring impedes postnatal activation of SCN-VAP neurons, which suppresses pubertal onset in AVPV-kisspeptin neurons and reproductive endocrine axis, leading to delayed puberty and dysfunction of ovaries.
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Affiliation(s)
- Yajie Zhang
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
| | - Ye Xu
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
| | - Hong Ding
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, China; Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wenfeng Yu
- Key Laboratory of Endemic and Ethnic Diseases of Education Ministry, Guizhou Medical University, Guian New District, Guizhou, 550025, China.
| | - Ling Chen
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, China.
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Nicola AC, Ferreira LB, Mata MM, Vilhena-Franco T, Leite CM, Martins AB, Antunes-Rodrigues J, Poletini MO, Dornelles RCM. Vasopressinergic Activity of the Suprachiasmatic Nucleus and mRNA Expression of Clock Genes in the Hypothalamus-Pituitary-Gonadal Axis in Female Aging. Front Endocrinol (Lausanne) 2021; 12:652733. [PMID: 34504470 PMCID: PMC8421860 DOI: 10.3389/fendo.2021.652733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 07/06/2021] [Indexed: 11/13/2022] Open
Abstract
The important involvement of the suprachiasmatic nucleus (SCN) and the activity of vasopressinergic neurons in maintaining the rhythmicity of the female reproductive system depends on the mRNA transcription-translation feedback loops. Therefore, circadian clock function, like most physiological processes, is involved in the events that determine reproductive aging. This study describes the change of mRNA expression of clock genes, Per2, Bmal1, and Rev-erbα, in the hypothalamus-pituitary-gonadal axis (HPG) of female rats with regular cycle (RC) and irregular cycle (IC), and the vasopressinergic neurons activity in the SCN and kisspeptin neurons in the arcuate nucleus (ARC) of these animals. Results for gonadotropins and the cFos/AVP-ir neurons in the SCN of IC were higher, but kisspeptin-ir was minor. Change in the temporal synchrony of the clock system in the HPG axis, during the period prior to the cessation of ovulatory cycles, was identified. The analysis of mRNA for Per2, Bmal1, and Rev-erbα in the reproductive axis of adult female rodents shows that the regularity of the estrous cycle is guaranteed by alternation in the amount of expression of Bmal1 and Per2, and Rev-erbα and Bmal1 between light and dark phases, which ceases to occur and contributes to determining reproductive senescence. These results showed that the desynchronization between the central and peripheral circadian clocks contributes to the irregularity of reproductive events. We suggest that the feedback loops of clock genes on the HPG axis modulate the spontaneous transition from regular to irregular cycle and to acyclicity in female rodents.
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Affiliation(s)
- Angela Cristina Nicola
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas—SBFis/UNESP, Department of Basic Sciences, Araçatuba, Brazil
- *Correspondence: Angela Cristina Nicola, ; Rita Cássia Menegati Dornelles,
| | - Larissa Brazoloto Ferreira
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas—SBFis/UNESP, Department of Basic Sciences, Araçatuba, Brazil
| | - Milene Mantovani Mata
- University of Sao Paulo (USP), School of Medicine of Ribeirão Preto, Department of Physiology, Ribeirão Preto, Brazil
| | - Tatiane Vilhena-Franco
- University of Sao Paulo (USP), School of Medicine of Ribeirão Preto, Department of Physiology, Ribeirão Preto, Brazil
| | | | - Andressa Busetti Martins
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas—SBFis/UEL, Department of Physiological Sciences, Londrina, Brazil
| | - José Antunes-Rodrigues
- University of Sao Paulo (USP), School of Medicine of Ribeirão Preto, Department of Physiology, Ribeirão Preto, Brazil
| | - Maristela Oliveira Poletini
- Federal University of Minas Gerais (UFMG), Institute of Biological Sciences, Department of Physiology and Biophysics, Belo Horizonte, Brazil
| | - Rita Cássia Menegati Dornelles
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas—SBFis/UNESP, Department of Basic Sciences, Araçatuba, Brazil
- São Paulo State University (UNESP), School of Dentistry, Department of Basic Sciences, Araçatuba, Brazil
- *Correspondence: Angela Cristina Nicola, ; Rita Cássia Menegati Dornelles,
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Rohr KE, Telega A, Savaglio A, Evans JA. Vasopressin regulates daily rhythms and circadian clock circuits in a manner influenced by sex. Horm Behav 2021; 127:104888. [PMID: 33202247 PMCID: PMC7855892 DOI: 10.1016/j.yhbeh.2020.104888] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/30/2020] [Accepted: 11/04/2020] [Indexed: 12/17/2022]
Abstract
Arginine vasopressin (AVP) is a neurohormone that alters cellular physiology through both endocrine and synaptic signaling. Circadian rhythms in AVP release and other biological processes are driven by the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. Loss of vasopressin signaling alters circadian behavior, but the basis of these effects remains unclear. Here we investigate the role of AVP signaling in circadian timekeeping by analyzing behavior and SCN function in a novel AVP-deficient mouse model. Consistent with previous work, loss of AVP signaling increases water consumption and accelerates recovery to simulated jetlag. We expand on these results to show that loss of AVP increases period, imprecision and plasticity of behavioral rhythms under constant darkness. Interestingly, the effect of AVP deficiency on circadian period was influenced by sex, with loss of AVP lengthening period in females but not males. Examining SCN function directly with ex vivo bioluminescence imaging of clock protein expression, we demonstrate that loss of AVP signaling modulates the period, precision, and phase relationships of SCN neurons in both sexes. This pattern of results suggests that there are likely sex differences in downstream targets of the SCN. Collectively, this work indicates that AVP signaling modulates circadian circuits in a manner influenced by sex, which provides new insight into sexual dimorphisms in the regulation of daily rhythms.
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Affiliation(s)
- Kayla E Rohr
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Adam Telega
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Alexandra Savaglio
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Jennifer A Evans
- Marquette University, Department of Biomedical Sciences, United States of America.
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Hrabovszky E, Takács S, Rumpler É, Skrapits K. The human hypothalamic kisspeptin system: Functional neuroanatomy and clinical perspectives. HANDBOOK OF CLINICAL NEUROLOGY 2021; 180:275-296. [PMID: 34225935 DOI: 10.1016/b978-0-12-820107-7.00017-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In mammals, kisspeptin neurons are the key components of the hypothalamic neuronal networks that regulate the onset of puberty, account for the pulsatile secretion of gonadotropin-releasing hormone (GnRH) and mediate negative and positive estrogen feedback signals to GnRH neurons. Being directly connected anatomically and functionally to the hypophysiotropic GnRH system, the major kisspeptin cell groups of the preoptic area/rostral hypothalamus and the arcuate (or infundibular) nucleus, respectively, are ideally positioned to serve as key nodes which integrate various types of environmental, endocrine, and metabolic signals that can influence fertility. This chapter provides an overview of the current state of knowledge on the anatomy, functions, and plasticity of brain kisspeptin systems based on the wide literature available from different laboratory and domestic species. Then, the species-specific features of human hypothalamic kisspeptin neurons are described, covering their topography, morphology, unique neuropeptide content, plasticity, and connectivity to hypophysiotropic GnRH neurons. Some newly emerging roles of central kisspeptin signaling in behavior and finally, clinical perspectives, are discussed.
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Affiliation(s)
- Erik Hrabovszky
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Budapest, Hungary.
| | - Szabolcs Takács
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Éva Rumpler
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Katalin Skrapits
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
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Coen CW, Bennett NC, Holmes MM, Faulkes CG. Neuropeptidergic and Neuroendocrine Systems Underlying Eusociality and the Concomitant Social Regulation of Reproduction in Naked Mole-Rats: A Comparative Approach. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1319:59-103. [PMID: 34424513 DOI: 10.1007/978-3-030-65943-1_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The African mole-rat family (Bathyergidae) includes the first mammalian species identified as eusocial: naked mole-rats. Comparative studies of eusocial and solitary mole-rat species have identified differences in neuropeptidergic systems that may underlie the phenomenon of eusociality. These differences are found in the oxytocin, vasopressin and corticotrophin-releasing factor (CRF) systems within the nucleus accumbens, amygdala, bed nucleus of the stria terminalis and lateral septal nucleus. As a corollary of their eusociality, most naked mole-rats remain pre-pubertal throughout life because of the presence of the colony's only reproductive female, the queen. To elucidate the neuroendocrine mechanisms that mediate this social regulation of reproduction, research on the hypothalamo-pituitary-gonadal axis in naked mole-rats has identified differences between the many individuals that are reproductively suppressed and the few that are reproductively mature: the queen and her male consorts. These differences involve gonadal steroids, gonadotrophin-releasing hormone-1 (GnRH-1), kisspeptin, gonadotrophin-inhibitory hormone/RFamide-related peptide-3 (GnIH/RFRP-3) and prolactin. The comparative findings in eusocial and solitary mole-rat species are assessed with reference to a broad range of studies on other mammals.
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Affiliation(s)
- Clive W Coen
- Reproductive Neurobiology, Division of Women's Health, Faculty of Life Sciences & Medicine, King's College London, London, UK.
| | - Nigel C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Melissa M Holmes
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada.,Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Canada.,Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
| | - Christopher G Faulkes
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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Korf HW, Møller M. Arcuate nucleus, median eminence, and hypophysial pars tuberalis. HANDBOOK OF CLINICAL NEUROLOGY 2021; 180:227-251. [PMID: 34225932 DOI: 10.1016/b978-0-12-820107-7.00015-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The arcuate nucleus (ARC) is located in the mediobasal hypothalamus and forms a morphological and functional entity with the median eminence (ME), the ARC-ME. The ARC comprises several distinct types of neurons controlling prolactin release, food intake, and metabolism as well as reproduction and onset of puberty. The ME lacks a blood-brain barrier and provides an entry for peripheral signals (nutrients, leptin, ghrelin). ARC neurons are adjacent to the wall of the third ventricle. This facilitates the exchange of signals from and to the cerebrospinal fluid. The ventricular wall is composed of tanycytes that serve different functions. Axons of ARC neurons contribute to the tuberoinfundibular tract terminating in the ME on the hypophysial portal vessels (HPV) and establish one of the neurohumoral links between the hypothalamus and the pituitary. ARC neurons are reciprocally connected with several other hypothalamic nuclei, the brainstem, and reward pathways. The hypophysial pars tuberalis (PT) is attached to the ME and the HPV. The PT, an important interface of the neuroendocrine system, is mandatory for the control of seasonal functions. This contribution provides an update of our knowledge about the ARC-ME complex and the PT which, inter alia, is needed to understand the pathophysiology of metabolic diseases and reproduction.
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Affiliation(s)
- Horst-Werner Korf
- Center for Anatomy and Brain Research, Institute for Anatomy, Düsseldorf, Germany.
| | - Morten Møller
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Ohara T, Nakamura TJ, Nakamura W, Tokuda IT. Modeling circadian regulation of ovulation timing: age-related disruption of estrous cyclicity. Sci Rep 2020; 10:16767. [PMID: 33028871 PMCID: PMC7541497 DOI: 10.1038/s41598-020-73669-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/14/2020] [Indexed: 11/21/2022] Open
Abstract
The circadian clocks within the hypothalamic–pituitary–gonadal axis control estrous cycles in female rodents. The suprachiasmatic nucleus (SCN), where the central clock is located, generates daily signals to trigger surge release of luteinizing hormone (LH), which in turn induces ovulation. It has been observed in aged rodents that output from the SCN such as neuronal firing activity is declined, and estrous cycles become irregular and finally stop. Circadian clock mutants display accelerated reproductive aging, suggesting the complicated interplay between the circadian system and the endocrine system. To investigate such circadian regulation of estrous cycles, we construct a mathematical model that describes dynamics of key hormones such as LH and of circadian clocks in the SCN and in the ovary, and simulate estrous cycles for various parameter values. Our simulation results demonstrate that reduction of the amplitude of the SCN signal, which is a symptom of aging, makes estrous cycles irregular. We also show that variation in the phase of the SCN signal and changes in the period of ovarian circadian clocks exacerbates the aging effect on estrous cyclicity. Our study suggests that misalignment between the SCN and ovarian circadian oscillations is one of the primary causes of the irregular estrous cycles.
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Affiliation(s)
- Takayuki Ohara
- Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany.
| | - Takahiro J Nakamura
- Laboratory of Animal Physiology, School of Agriculture, Meiji University, Tokyo, Japan
| | - Wataru Nakamura
- Department of Oral-Chrono Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Isao T Tokuda
- Department of Mechanical Engineering, Ritsumeikan University, Kyoto, Japan.
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Zhang Y, Cao X, Chen L, Qin Y, Xu Y, Tian Y, Chen L. Exposure of female mice to perfluorooctanoic acid suppresses hypothalamic kisspeptin-reproductive endocrine system through enhanced hepatic fibroblast growth factor 21 synthesis, leading to ovulation failure and prolonged dioestrus. J Neuroendocrinol 2020; 32:e12848. [PMID: 32307816 DOI: 10.1111/jne.12848] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 03/20/2020] [Accepted: 03/20/2020] [Indexed: 01/09/2023]
Abstract
Perfluorooctanoic acid (PFOA) is widely used in household applications. High-dose exposure to PFOA has been associated with increased risks of infertility and premature ovarian insufficiency in woman. PFOA can alter hepatic gene expression by activating peroxisome proliferator-activated receptor α (PPARα). The present study investigated whether exposure to PFOA via PPARα activation alters the synthesis of hepatic fibroblast growth factor 21 (FGF21) to disturb female neuroendocrine and reproductive function. In the present study, we show that the oral administration of PFOA (2 or 5 mg kg-1 ) in adult female mice (PFOA mice) caused prolonged dioestrous, a reduction in the number of corpora lutea and decreased levels of hypothalamic gonadotrophin-releasing hormone, serum progesterone and luteinising hormone (LH). Exposure to PFOA decreased the expression of vasopressin in the suprachiasmatic nucleus (SCN) and kisspeptin in the anteroventral periventricular nucleus (AVPV) with deficits in preovulation or oestrogen-induced LH surge. PFOA via activation of PPARα increased dose-dependently hepatic FGF21 expression, leading to elevated serum and hypothalamic FGF21 concentrations. Treatment of PFOA mice with the PPARα antagonist GW6471 or the FGF21 inhibitor PD173074 rescued SCN vasopressin and AVPV-kisspeptin expression. Either administration of GW6471 and PD173074 or treatment with vasopressin and the G protein coupled receptor 54 agonist kisspeptin-10 in PFOA-mice was able to recover the regular oestrous cycle, ovulation ability, LH surge production and reproductive hormone levels. The present study provides in vivo evidence that exposure to PFOA (≥2 mg kg-1 ) in mice causes down-regulation of the kisspeptin-reproductive endocrine system by enhancing PPARα-mediated hepatic FGF21 expression. The liver-brain reproductive endocrine disorder caused by PFOA exposure may lead to prolonged dioestrous and ovulation failure.
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Affiliation(s)
- Yajie Zhang
- State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing, China
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Xinyuan Cao
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Lin Chen
- MOE and Shanghai Key Laboratory of Children's Environment Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yaoyao Qin
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Ye Xu
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Ying Tian
- MOE and Shanghai Key Laboratory of Children's Environment Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ling Chen
- State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing, China
- Department of Physiology, Nanjing Medical University, Nanjing, China
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Köves K, Szabó E, Kántor O, Heinzlmann A, Szabó F, Csáki Á. Current State of Understanding of the Role of PACAP in the Hypothalamo-Hypophyseal Gonadotropin Functions of Mammals. Front Endocrinol (Lausanne) 2020; 11:88. [PMID: 32210912 PMCID: PMC7067695 DOI: 10.3389/fendo.2020.00088] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 02/11/2020] [Indexed: 01/25/2023] Open
Abstract
PACAP was discovered 30 years ago in Dr. Akira Arimura's laboratory. In the past three decades since then, it has become evident that this peptide plays numerous crucial roles in mammalian organisms. The most important functions of PACAP are the following: 1. neurotransmitter, 2. neuromodulator, 3. hypophysiotropic hormone, 4. neuroprotector. This paper reviews the accumulated data regarding the distribution of PACAP and its receptors in the mammalian hypothalamus and pituitary gland, the role of PACAP in the gonadotropin hormone secretion of females and males. The review also summarizes the interaction between PACAP, GnRH, and sex steroids as well as hypothalamic peptides including kisspeptin. The possible role of PACAP in reproductive functions through the biological clock is also discussed. Finally, the significance of PACAP in the hypothalamo-hypophysial system is considered and the facts missing, that would help better understand the function of PACAP in this system, are also highlighted.
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Affiliation(s)
- Katalin Köves
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Enikő Szabó
- Department of Conservative Dentistry, Faculty of Dentistry, Semmelweis University, Budapest, Hungary
| | - Orsolya Kántor
- Department of Molecular Embryology, Medical Faculty, Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg, Germany
| | - Andrea Heinzlmann
- Department of Anatomy and Histology, University of Veterinary Sciences, Budapest, Hungary
| | - Flóra Szabó
- Department of Pediatrics, Virginia Commonwealth University, Richmond, VA, United States
| | - Ágnes Csáki
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
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Coyle CS, Caso F, Tolla E, Barrett P, Onishi KG, Tello JA, Stevenson TJ. Ovarian hormones induce de novo DNA methyltransferase expression in the Siberian hamster suprachiasmatic nucleus. J Neuroendocrinol 2020; 32:e12819. [PMID: 31800973 DOI: 10.1111/jne.12819] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/30/2019] [Accepted: 12/02/2019] [Indexed: 01/11/2023]
Abstract
The present study investigated neuroanatomically localised changes in de novo DNA methyltransferase expression in the female Siberian hamster (Phodopus sungorus). The objectives were to identify the neuroendocrine substrates that exhibit rhythmic Dnmt3a and Dnmt3b expression across the oestrous cycle and also examine the role of ovarian steroids. Hypothalamic Dnmt3a expression was observed to significantly increase during the transition from pro-oestrous to oestrous. A single bolus injection of diethylstilbestrol and progesterone was sufficient to increase Dnmt3a cell numbers and Dnmt3b immunoreactive intensity in the suprachiasmatic nucleus. In vitro analyses using an embryonic rodent cell line revealed that diethylstilbestrol was sufficient to induce Dnmt3b expression. Up-regulating DNA methylation in vitro reduced the expression of vasoactive intestinal polypeptide, Vip, and the circadian clock gene, Bmal1. Together, these data indicate that ovarian steroids drive de novo DNA methyltransferase expression in the mammalian suprachiasmatic nucleus and increased methylation may regulate genes involved in the circadian timing of oestrous: Vip and Bmal1. Overall, epigenetically mediated neuroendocrine reproductive events may reflect an evolutionarily ancient process involved in the timing of female fertility.
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Affiliation(s)
- Chris S Coyle
- Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Federico Caso
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Elisabetta Tolla
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Perry Barrett
- Rowett Institute, University of Aberdeen, Aberdeen, UK
| | - Kenneth G Onishi
- Department of Psychology, Institute for Mind and Biology, University of Chicago, Chicago, IL, USA
| | - Javier A Tello
- School of Medicine, University of St Andrews, St Andrews, UK
| | - Tyler John Stevenson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
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Silva CC, Cortés GD, Javier CY, Flores A, Domínguez R. A neural circadian signal essential for ovulation is generated in the suprachiasmatic nucleus during each stage of the oestrous cycle. Exp Physiol 2019; 105:258-269. [PMID: 31769118 DOI: 10.1113/ep087942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 11/25/2019] [Indexed: 12/31/2022]
Abstract
NEW FINDINGS What is the central question of this study? Is the suprachiasmatic nucleus the structure that generates the neural circadian signals that occur during every stage of the oestrous cycle, not only pro-oestrus, and are these signals essential for proper regulation of ovulation? What is the main finding and its importance? Transient inhibition of Na+ -dependent action potentials in the suprachiasmatic nucleus by tetrodotoxin microinjection at 14.00 h inhibits ovulation irrespective of the stage of the oestrous cycle at which the procedure is performed. Microinjection of saline solution into the suprachiasmatic nucleus has a disruptive effect on ovulation that depends on the stage of the cycle at which it is administered. ABSTRACT Reproduction is a highly timed process that depends on both the reproductive and circadian systems. The core oscillator of the latter resides at the suprachiasmatic nuclei (SCN) and it is pivotal for the regulation of the pro-oestrus pre-ovulatory surge of gonadotropins in females. There is evidence to suggest that this system may be involved in the regulation of neuroendocrine events that are essential for ovulation and that occur prior to pro-oestrus. We explored this possibility by transiently inactivating the SCN. Female rats were implanted with guide cannulas aimed at the SCN. After recovery of the oestrous cycle, animals were injected with tetrodotoxin (TTX), artificial cerebrospinal fluid (ACSF) or saline solution while freely moving. Injections were performed at 14.00 h of each stage of the oestrous cycle. Animals were killed on the next predicted oestrus day, the number of ova shed was counted and intact rats at oestrus stage were used as absolute control. ACSF did not modify ovulation. Saline solution blocked ovulation in oestrus- and dioestrus-injected rats. Irrespectively of the stage of the oestrous cycle, TTX blocked ovulation. These results lead us to suggest that a neural circadian signal, pivotal for triggering the gonadotropin pre-ovulatory surge, arises from the SCN during the critical window of pro-oestrus. We also suggest that a similar signal, needed for the regulation of other events that are indispensable for proper regulation of ovulation, is also generated in this nucleus during the other stages of the cycle at a similar time.
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Affiliation(s)
- Carlos-Camilo Silva
- Chronobiology of Reproduction Research Lab, Biology of Reproduction Research Unit, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, México.,Developmental Biology Lab, Biology of Reproduction Research Unit, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, México
| | - Georgina Daniela Cortés
- Chronobiology of Reproduction Research Lab, Biology of Reproduction Research Unit, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, México
| | - Cintia Yolanda Javier
- Chronobiology of Reproduction Research Lab, Biology of Reproduction Research Unit, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, México
| | - Angélica Flores
- Chronobiology of Reproduction Research Lab, Biology of Reproduction Research Unit, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, México.,Developmental Biology Lab, Biology of Reproduction Research Unit, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, México
| | - Roberto Domínguez
- Chronobiology of Reproduction Research Lab, Biology of Reproduction Research Unit, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, México.,Developmental Biology Lab, Biology of Reproduction Research Unit, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, México
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The Homeodomain Transcription Factors Vax1 and Six6 Are Required for SCN Development and Function. Mol Neurobiol 2019; 57:1217-1232. [PMID: 31705443 DOI: 10.1007/s12035-019-01781-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 09/12/2019] [Indexed: 12/13/2022]
Abstract
The brain's primary circadian pacemaker, the suprachiasmatic nucleus (SCN), is required to translate day-length and circadian rhythms into neuronal, hormonal, and behavioral rhythms. Here, we identify the homeodomain transcription factor ventral anterior homeobox 1 (Vax1) as required for SCN development, vasoactive intestinal peptide expression, and SCN output. Previous work has shown that VAX1 is required for gonadotropin-releasing hormone (GnRH/LHRH) neuron development, a neuronal population controlling reproductive status. Surprisingly, the ectopic expression of a Gnrh-Cre allele (Gnrhcre) in the SCN confirmed the requirement of both VAX1 (Vax1flox/flox:Gnrhcre, Vax1Gnrh-cre) and sine oculis homeobox protein 6 (Six6flox/flox:Gnrhcre, Six6Gnrh-cre) in SCN function in adulthood. To dissociate the role of Vax1 and Six6 in GnRH neuron and SCN function, we used another Gnrh-cre allele that targets GnRH neurons, but not the SCN (Lhrhcre). Both Six6Lhrh-cre and Vax1Lhrh-cre were infertile, and in contrast to Vax1Gnrh-cre and Six6Gnrh-cre mice, Six6Lhrh-cre and Vax1Lhrh-cre had normal circadian behavior. Unexpectedly, ~ 1/4 of the Six6Gnrh-cre mice were unable to entrain to light, showing that ectopic expression of Gnrhcre impaired function of the retino-hypothalamic tract that relays light information to the brain. This study identifies VAX1, and confirms SIX6, as transcription factors required for SCN development and function and demonstrates the importance of understanding how ectopic CRE expression can impact the results.
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40
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Gotlieb N, Baker CN, Moeller J, Kriegsfeld LJ. Time-of-day-dependent sensitivity of the reproductive axis to RFamide-related peptide-3 inhibition in female Syrian hamsters. J Neuroendocrinol 2019; 31:e12798. [PMID: 31550401 PMCID: PMC6991702 DOI: 10.1111/jne.12798] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 08/15/2019] [Accepted: 09/19/2019] [Indexed: 12/15/2022]
Abstract
In spontaneously ovulating rodent species, the timing of the luteinising hormone (LH) surge is controlled by the master circadian pacemaker in the suprachiasmatic nucleus (SCN). The SCN initiates the LH surge via the coordinated control of two opposing neuropeptidergic systems that lie upstream of the gonadotrophin-releasing hormone (GnRH) neuronal system: the stimulatory peptide, kisspeptin, and the inhibitory peptide, RFamide-related peptide-3 (RFRP-3; the mammalian orthologue of avian gonadotrophin-inhibitory hormone [GnIH]). We have previously shown that the GnRH system exhibits time-dependent sensitivity to kisspeptin stimulation, further contributing to the precise timing of the LH surge. To examine whether this time-dependent sensitivity of the GnRH system is unique to kisspeptin or a more common mechanism of regulatory control, we explored daily changes in the response of the GnRH system to RFRP-3 inhibition. Female Syrian hamsters were ovariectomised to eliminate oestradiol (E2 )-negative-feedback and RFRP-3 or saline was centrally administered in the morning or late afternoon. LH concentrations and Lhβ mRNA expression did not differ between morning RFRP-3-and saline-treated groups, although they were markedly suppressed by RFRP-3 administration in the afternoon. However, RFRP-3 inhibition of circulating LH at the time of the surge does not appear to act via the GnRH system because no differences in medial preoptic area Gnrh or RFRP-3 receptor Gpr147 mRNA expression were observed. Rather, RFRP-3 suppressed arcuate nucleus Kiss1 mRNA expression and potentially impacted pituitary gonadotrophs directly. Taken together, these findings reveal time-dependent responsiveness of the reproductive axis to RFRP-3 inhibition, possibly via variation in the sensitivity of arcuate nucleus kisspeptin neurones to this neuropeptide.
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Affiliation(s)
- Neta Gotlieb
- Department of Psychology, University of California Berkeley, Berkeley, CA, USA
| | - Cydni N. Baker
- Department of Psychology, University of California Berkeley, Berkeley, CA, USA
| | - Jacob Moeller
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
| | - Lance J. Kriegsfeld
- Department of Psychology, University of California Berkeley, Berkeley, CA, USA
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
- Graduate Group in Endocrinology, University of California Berkeley, Berkeley, CA, USA
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
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41
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Bahougne T, Angelopoulou E, Jeandidier N, Simonneaux V. Individual evaluation of luteinizing hormone in aged C57BL/6 J female mice. GeroScience 2019; 42:323-331. [PMID: 31641925 DOI: 10.1007/s11357-019-00104-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/12/2019] [Indexed: 12/23/2022] Open
Abstract
In female mammals, reproductive senescence is a complex process involving progressive ovarian dysfunction associated with an altered central control of the hypothalamic-pituitary axis. The objective of this study was to compare the longitudinal change in preovulatory luteinizing hormone (LH) secretion as well as estrous cycle in individual C57BL/6 J female mice at 3, 6, 9 and 12 months. Amplitude and timing of LH secretion at the surge were similar from 3 to 9 months but were altered in 12-month old mice with a significant decrease of more than 50% of peak LH value and a 2 h delay in the occurrence of the LH surge as compared to younger mice. The analysis of two to three successive LH surges at 3, 6, 9 and 12 months showed low and similar intra-individual variability at all ages. The estrous cycle length and intra/inter variability were stable over the age. This study shows that female mice in regular environmental conditions display stable LH surge timing and amplitude up to 9 months, but at 12 months, the LH surge is delayed with a reduced amplitude, however without overt modification in the estrous cycles. Analysis of individual preovulatory LH secretion and estrous cycle indicates that mice can be followed up to 9 months to investigate the detrimental effects of various parameters on mouse reproductive activity.
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Affiliation(s)
- Thibault Bahougne
- Institut des Neurosciences Cellulaires et Intégratives, (UPR CNRS 3212) and Université de Strasbourg, Strasbourg, France. .,Service d'Endocrinologie et Diabète, Hôpitaux Universitaires de Strasbourg, 1 place de l'hôpital, 67000, Strasbourg, France.
| | - Eleni Angelopoulou
- Institut des Neurosciences Cellulaires et Intégratives, (UPR CNRS 3212) and Université de Strasbourg, Strasbourg, France
| | - Nathalie Jeandidier
- Service d'Endocrinologie et Diabète, Hôpitaux Universitaires de Strasbourg, 1 place de l'hôpital, 67000, Strasbourg, France
| | - Valérie Simonneaux
- Institut des Neurosciences Cellulaires et Intégratives, (UPR CNRS 3212) and Université de Strasbourg, Strasbourg, France
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Matsuda F, Ohkura S, Magata F, Munetomo A, Chen J, Sato M, Inoue N, Uenoyama Y, Tsukamura H. Role of kisspeptin neurons as a GnRH surge generator: Comparative aspects in rodents and non-rodent mammals. J Obstet Gynaecol Res 2019; 45:2318-2329. [PMID: 31608564 DOI: 10.1111/jog.14124] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 08/30/2019] [Indexed: 02/01/2023]
Abstract
Ovulation is an essential phenomenon for reproduction in mammalian females along with follicular growth. It is well established that gonadal function is controlled by the neuroendocrine system called the hypothalamus-pituitary-gonadal (HPG) axis. Gonadotropin-releasing hormone (GnRH) neurons, localized in the hypothalamus, had been considered to be the head in governing the HPG axis for a long time until the discovery of kisspeptin. In females, induction of ovulation and folliculogenesis has been linked to a surge mode and pulse mode of GnRH releases, respectively. The mechanisms of how the two modes of GnRH are differently regulated had long remained elusive. The discovery of kisspeptin neurons, distributed in two hypothalamic nuclei, such as the arcuate nucleus in the caudal hypothalamus and preoptic area or the anteroventral periventricular nucleus in the rostral hypothalamic regions, and analyses of the detailed functions of kisspeptin neurons have led marked progress on the understanding of different mechanisms regulating GnRH surges (ovulation) and GnRH pulses (folliculogenesis). The present review will focus on the role of kisspeptin neurons as the GnRH surge generator, including the sexual differentiation of the surge generation system and factors that regulate the surge generator. Comparative aspects between mammalian species are especially focused on.
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Affiliation(s)
- Fuko Matsuda
- Laboratory of Theriogenology, Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo, Japan
| | - Satoshi Ohkura
- Laboratory of Animal Production Science, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Fumie Magata
- Laboratory of Theriogenology, Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo, Japan
| | - Arisa Munetomo
- Laboratory of Theriogenology, Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo, Japan
| | - Jing Chen
- Laboratory of Theriogenology, Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo, Japan
| | - Marimo Sato
- Laboratory of Theriogenology, Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo, Japan
| | - Naoko Inoue
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Yoshihisa Uenoyama
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Hiroko Tsukamura
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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Vasopressin regulates hypothalamic GnRH synthesis: Histomorphological evidence in hypothalamus and biological effects in GT1-7 cells. Life Sci 2019; 227:166-174. [PMID: 31026452 DOI: 10.1016/j.lfs.2019.04.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/17/2019] [Accepted: 04/22/2019] [Indexed: 01/03/2023]
Abstract
AIMS To investigate the direct histomorphological clues and observe the biological effects of VP acting on gonadotropin-releasing hormone (GnRH) secretion. MAIN METHODS Immunofluorescence was conducted to investigate the expressions of GnRH and VP in experimental left varicocele (ELV) rats and ELV repair rats. The colocalization of GnRH and VP was observed by electron microscopy immunohistochemistry. The protein-protein interaction between GnRH and VP was tested by co-immunoprecipitation (co-IP) and the proximity ligation assay (PLA). The effects of intracellular and extracellular VP on GnRH and relative transcription factors (Oct-1, Otx2, Pbx1b and DREAM) were respectively evaluated in VP overexpressed and VP treated GT1-7 cells. KEY FINDINGS Both hypothalamic GnRH and VP decreased in ELV rats and recovered by ELV repair. The overlapped immunolocalizations of GnRH and VP mainly distributed in the lateral part of the arcuate nucleus (ArcL) and median eminence (ME) with a Manders' overlap coefficient of 0.743 ± 0.117. Immunoreactive substances of GnRH and VP existed in the same and adjacent terminals. VP overexpression did not cause any significant effects on the expressions of GnRH and Oct-1, as well as GnRH promoter activity. While 50-200 pg/ml VP treatments increased GnRH mRNA levels in a dose- and time-dependent manner in GT1-7 cells. Additionally, 200 pg/ml VP triggered a marked promotion of expressions of GnRH, Oct-1, Oxt2 Pbx1b and DREAM, as well as GnRH promoter activity (P < 0.05). SIGNIFICANCE The results reveal the colocalization and interaction of VP and GnRH, which will be conducive to explain the effects and mechanisms of VP acting on reproduction.
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Tonsfeldt KJ, Schoeller EL, Brusman LE, Cui LJ, Lee J, Mellon PL. The Contribution of the Circadian Gene Bmal1 to Female Fertility and the Generation of the Preovulatory Luteinizing Hormone Surge. J Endocr Soc 2019; 3:716-733. [PMID: 30906911 PMCID: PMC6425515 DOI: 10.1210/js.2018-00228] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 02/08/2019] [Indexed: 12/19/2022] Open
Abstract
In rodents, the preovulatory LH surge is temporally gated, but the timing cue is unknown. Estrogen primes neurons in the anteroventral periventricular nucleus (AVPV) to secrete kisspeptin, which potently activates GnRH neurons to release GnRH, eliciting a surge of LH to induce ovulation. Deletion of the circadian clock gene Bmal1 results in infertility. Previous studies have found that Bmal1 knockout (KO) females do not display an LH surge at any time of day. We sought to determine whether neuroendocrine disruption contributes to the absence of the LH surge. Because Kiss1 expression in the AVPV is critical for regulating ovulation, we hypothesized that this population is disrupted in Bmal1 KO females. However, we found an appropriate rise in AVPV Kiss1 and Fos mRNA at the time of lights out in ovariectomized estrogen-treated animals, despite the absence of a measureable increase in LH. Furthermore, Bmal1 KO females have significantly increased LH response to kiss-10 administration, although the LH response to GnRH was unchanged. We then created Kiss1- and GnRH-specific Bmal1 KO mice to examine whether Bmal1 expression is necessary within either kisspeptin or GnRH neurons. We detected no significant differences in any measured reproductive parameter. Our results indicate that disruption of the hypothalamic regulation of fertility in the Bmal1 KO females is not dependent on endogenous clocks within either the GnRH or kisspeptin neurons.
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Affiliation(s)
- Karen J Tonsfeldt
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California San Diego, La Jolla, California
| | - Erica L Schoeller
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California San Diego, La Jolla, California
| | - Liza E Brusman
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California San Diego, La Jolla, California
| | - Laura J Cui
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California San Diego, La Jolla, California
| | - Jinkwon Lee
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California San Diego, La Jolla, California
| | - Pamela L Mellon
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California San Diego, La Jolla, California
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45
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Yeo SH, Kyle V, Blouet C, Jones S, Colledge WH. Mapping neuronal inputs to Kiss1 neurons in the arcuate nucleus of the mouse. PLoS One 2019; 14:e0213927. [PMID: 30917148 PMCID: PMC6436706 DOI: 10.1371/journal.pone.0213927] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 03/04/2019] [Indexed: 12/20/2022] Open
Abstract
The normal function of the mammalian reproductive axis is strongly influenced by physiological, metabolic and environmental factors. Kisspeptin neuropeptides, encoded by the Kiss1 gene, are potent regulators of the mammalian reproductive axis by stimulating gonadodropin releasing hormone secretion from the hypothalamus. To understand how the reproductive axis is modulated by higher order neuronal inputs we have mapped the afferent circuits into arcuate (ARC) Kiss1 neurons. We used a transgenic mouse that expresses the CRE recombinase in Kiss1 neurons for conditional viral tracing with genetically modified viruses. CRE-mediated activation of these viruses in Kiss1 neurons allows the virus to move transynaptically to label neurons with primary or secondary afferent inputs into the Kiss1 neurons. Several regions of the brain showed synaptic connectivity to arcuate Kiss1 neurons including proopiomelanocortin neurons in the ARC itself, kisspeptin neurons in the anteroventral periventricular nucleus, vasopressin neurons in the supraoptic and suprachiasmatic nuclei, thyrotropin releasing neurons in the paraventricular nucleus and unidentified neurons in other regions including the subfornical organ, amygdala, interpeduncular nucleus, ventral premammilary nucleus, basal nucleus of stria terminalis and the visual, somatosensory and piriform regions of the cortex. These data provide an insight into how the activity of Kiss1 neurons may be regulated by metabolic signals and provide a detailed neuroanatomical map for future functional studies.
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Affiliation(s)
- Shel-Hwa Yeo
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Victoria Kyle
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Clemence Blouet
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Susan Jones
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - William Henry Colledge
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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Angelopoulou E, Quignon C, Kriegsfeld LJ, Simonneaux V. Functional Implications of RFRP-3 in the Central Control of Daily and Seasonal Rhythms in Reproduction. Front Endocrinol (Lausanne) 2019; 10:183. [PMID: 31024442 PMCID: PMC6467943 DOI: 10.3389/fendo.2019.00183] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/05/2019] [Indexed: 12/20/2022] Open
Abstract
Adaptation of reproductive activity to environmental changes is essential for breeding success and offspring survival. In mammals, the reproductive system displays regular cycles of activation and inactivation which are synchronized with seasonal and/or daily rhythms in environmental factors, notably light intensity and duration. Thus, most species adapt their breeding activity along the year to ensure that birth and weaning of the offspring occur at a time when resources are optimal. Additionally, female reproductive activity is highest at the beginning of the active phase during the period of full oocyte maturation, in order to improve breeding success. In reproductive physiology, it is therefore fundamental to delineate how geophysical signals are integrated in the hypothalamo-pituitary-gonadal axis, notably by the neurons expressing gonadotropin releasing hormone (GnRH). Several neurochemicals have been reported to regulate GnRH neuronal activity, but recently two hypothalamic neuropeptides belonging to the superfamily of (Arg)(Phe)-amide peptides, RFRP-3 and kisspeptin, have emerged as critical for the integration of environmental cues within the reproductive axis. The goal of this review is to survey the current understanding of the role played by RFRP-3 in the temporal regulation of reproduction, and consider how its effect might combine with that of kisspeptin to improve the synchronization of reproduction to environmental challenges.
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Affiliation(s)
- Eleni Angelopoulou
- Institut des Neurosciences Cellulaires et Intégratives (CNRS UPR 3212), Université de Strasbourg, Strasbourg, France
- Netherlands Institute for Neuroscience (NIN), Amsterdam, Netherlands
| | - Clarisse Quignon
- Institut des Neurosciences Cellulaires et Intégratives (CNRS UPR 3212), Université de Strasbourg, Strasbourg, France
| | - Lance J. Kriegsfeld
- Department of Psychology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Valérie Simonneaux
- Institut des Neurosciences Cellulaires et Intégratives (CNRS UPR 3212), Université de Strasbourg, Strasbourg, France
- *Correspondence: Valérie Simonneaux
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Simonneaux V. A Kiss to drive rhythms in reproduction. Eur J Neurosci 2018; 51:509-530. [DOI: 10.1111/ejn.14287] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/08/2018] [Accepted: 11/19/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Valérie Simonneaux
- Institut des Neurosciences Cellulaires et IntégrativesCNRSUniversité de Strasbourg Strasbourg France
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Acevedo-Rodriguez A, Kauffman AS, Cherrington BD, Borges CS, Roepke TA, Laconi M. Emerging insights into hypothalamic-pituitary-gonadal axis regulation and interaction with stress signalling. J Neuroendocrinol 2018; 30. [PMID: 29524268 PMCID: PMC6129417 DOI: 10.1111/jne.12590] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Reproduction and fertility are regulated via hormones of the hypothalamic-pituitary-gonadal (HPG) axis. Control of this reproductive axis occurs at all levels, including the brain and pituitary, and allows for the promotion or inhibition of gonadal sex steroid secretion and function. In addition to guiding proper gonadal development and function, gonadal sex steroids also act in negative- and positive-feedback loops to regulate reproductive circuitry in the brain, including kisspeptin neurones, thereby modulating overall HPG axis status. Additional regulation is also provided by sex steroids made within the brain, including neuroprogestins. Furthermore, because reproduction and survival need to be coordinated and balanced, the HPG axis is able to modulate (and be modulated by) stress hormone signalling, including cortiscosterone, from the hypothalamic-pituitary-adrenal (HPA) axis. This review covers recent data related to the neural, hormonal and stress regulation of the HPG axis and emerging interactions between the HPG and HPA axes, focusing on actions at the level of the brain and pituitary.
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Affiliation(s)
- A Acevedo-Rodriguez
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - A S Kauffman
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, CA, USA
| | - B D Cherrington
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - C S Borges
- Department of Morphology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu, Brazil
| | - T A Roepke
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - M Laconi
- Laboratorio de Fisiopatología Ovárica, Instituto de Medicina y Biología Experimental de Cuyo (IMBECU - CONICET), Universidad Juan Agustín Maza, Mendoza, Argentina
- Facultad de Ciencias Veterinarias y Ambientales, Universidad Juan Agustín Maza, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad de Mendoza, Mendoza, Argentina
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Simonneaux V, Piet R. Neuroendocrine pathways driving daily rhythms in the hypothalamic pituitary gonadal axis of female rodents. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Medger K, Bennett NC, Chimimba CT, Oosthuizen MK, Mikkelsen JD, Coen CW. Analysis of gonadotrophin-releasing hormone-1 and kisspeptin neuronal systems in the nonphotoregulated seasonally breeding eastern rock elephant-shrew (Elephantulus myurus). J Comp Neurol 2018; 526:2388-2405. [PMID: 30004584 DOI: 10.1002/cne.24498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 06/08/2018] [Accepted: 06/19/2018] [Indexed: 12/18/2022]
Abstract
Of the 18 sub-Saharan elephant-shrew species, only eastern rock elephant-shrews reproduce seasonally throughout their distribution, a process seemingly independent of photoperiod. The present study characterizes gonadal status and location/intensity of gonadotrophin-releasing hormone-1 (GnRH-1) and kisspeptin immunoreactivities in this polyovulating species in the breeding and nonbreeding seasons. GnRH-1-immunoreactive (ir) cell bodies are predominantly in the medial septum, diagonal band, and medial preoptic area; processes are generally sparse except in the external median eminence. Kisspeptin-ir cell bodies are detected only within the arcuate nucleus; the density of processes is generally low, except in the septohypothalamic nucleus, ventromedial bed nucleus of the stria terminalis, arcuate nucleus, and internal and external median eminence. Kisspeptin-ir processes are negligible at locations containing GnRH-1-ir cell bodies. The external median eminence is the only site with conspicuously overlapping distributions of the respective immunoreactivities and, accordingly, a putative site for kisspeptin's regulation of GnRH-1 release in this species. In the nonbreeding season in males, there is an increase in the rostral population of GnRH-1-ir cell bodies and density of GnRH-1-ir processes in the median eminence. In both sexes, the breeding season is associated with increased kisspeptin-ir process density in the rostral periventricular area of the third ventricle and arcuate nucleus; at the latter site, this is positively correlated with gonadal mass. Cross-species comparisons lead us to hypothesize differential mechanisms within these peptidergic systems: that increased GnRH-1 immunoreactivity during the nonbreeding season reflects increased accumulation with reduced release; that increased kisspeptin immunoreactivity during the breeding season reflects increased synthesis with increased release.
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Affiliation(s)
- Katarina Medger
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Nigel C Bennett
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Christian T Chimimba
- Department of Zoology and Entomology, DST-NRF Centre of Excellence for Invasion Biology (CIB), University of Pretoria, Pretoria, South Africa
| | - Maria K Oosthuizen
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Jens D Mikkelsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Clive W Coen
- Reproductive Neurobiology, Division of Women's Health, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
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