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Dardente H, Lomet D, Robert V, Lasserre O, Gonzalez AA, Mialhe X, Beltramo M. Photoperiod, but not progesterone, has a strong impact upon the transcriptome of the medio-basal hypothalamus in female goats and ewes. Mol Cell Endocrinol 2024; 588:112216. [PMID: 38556161 DOI: 10.1016/j.mce.2024.112216] [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: 11/23/2023] [Revised: 03/11/2024] [Accepted: 03/24/2024] [Indexed: 04/02/2024]
Abstract
Photoperiod is the main environmental driver of seasonal responses in organisms living at temperate and polar latitudes. Other external cues such as food and temperature, and internal cues including hormones, intervene to fine-tune phasing of physiological functions to the solar year. In mammals, the medio-basal hypothalamus (MBH) is the key integrator of these cues, which orchestrates a wide array of seasonal functions, including breeding. Here, using RNAseq and RT-qPCR, we demonstrate that molecular components of the photoperiodic response previously identified in ewes are broadly conserved in does (female goats, Capra hircus), with a common core of ∼50 genes. This core group can be defined as the "MBH seasonal trancriptome", which includes key players of the pars tuberalis-tanycytes neuroendocrine retrograde pathway that governs intra-MBH photoperiodic switches of triiodothyronine (T3) production (Tshb, Eya3, Dio2 and SlcO1c1), the two histone methyltransferases Suv39H2 and Ezh2 and the secreted protein Vmo1. Prior data in ewes revealed that T3 and estradiol (E2), both key hormones for the proper timing of seasonal breeding, differentially impact the MBH seasonal transcriptome, and identified cellular and molecular targets through which these hormones might act. In contrast, information regarding the potential impact of progesterone (P4) upon the MBH transcriptome was nonexistent. Here, we demonstrate that P4 has no discernible transcriptional impact in either does or ewes. Taken together, our data show that does and ewes possess a common core set of photoperiod-responsive genes in the MBH and conclusively demonstrate that P4 is not a key regulator of the MBH transcriptome.
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Affiliation(s)
- Hugues Dardente
- INRAE, CNRS, Université de Tours, PRC, 37380, Nouzilly, France.
| | - Didier Lomet
- INRAE, CNRS, Université de Tours, PRC, 37380, Nouzilly, France
| | - Vincent Robert
- INRAE, CNRS, Université de Tours, PRC, 37380, Nouzilly, France
| | | | - Anne-Alicia Gonzalez
- MGX-Montpellier GenomiX, Univ. Montpellier, CNRS, INSERM, 34094, Montpellier, France
| | - Xavier Mialhe
- MGX-Montpellier GenomiX, Univ. Montpellier, CNRS, INSERM, 34094, Montpellier, France
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Agus S, Yavuz Y, Atasoy D, Yilmaz B. Postweaning Social Isolation Alters Puberty Onset by Suppressing Electrical Activity of Arcuate Kisspeptin Neurons. Neuroendocrinology 2024; 114:439-452. [PMID: 38271999 PMCID: PMC11098025 DOI: 10.1159/000535721] [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: 07/06/2023] [Accepted: 11/15/2023] [Indexed: 01/27/2024]
Abstract
INTRODUCTION Postweaning social isolation (PWSI) in rodents is an advanced psychosocial stress model in early life. Some psychosocial stress, such as restrain and isolation, disrupts reproductive physiology in young and adult periods. Mechanisms of early-life stress effects on central regulation of reproduction need to be elucidated. We have investigated the effects of PWSI on function of arcuate kisspeptin (ARCKISS1) neurons by using electrophysiological techniques combining with monitoring of puberty onset and estrous cycle in male and female Kiss1-Cre mice. METHODS Female mice were monitored for puberty onset with vaginal opening examination during social isolation. After isolation, the estrous cycle of female mice was monitored with vaginal cytology. Anxiety-like behavior of mice was determined by an elevated plus maze test. Effects of PWSI on electrophysiology of ARCKISS1 neurons were investigated by the patch clamp method after intracranial injection of AAV-GFP virus into arcuate nucleus of Kiss1-Cre mice after the isolation period. RESULTS We found that both male and female isolated mice showed anxiety-like behavior. PWSI caused delay in vaginal opening and extension in estrous cycle length. Spontaneous-firing rates of ARCKISS1 neurons were significantly lower in the isolated male and female mice. The peak amplitude of inhibitory postsynaptic currents to ARCKISS1 neurons was higher in the isolated mice, while frequency of excitatory postsynaptic currents was higher in group-housed mice. CONCLUSION These findings demonstrate that PWSI alters pre- and postpubertal reproductive physiology through metabolic and electrophysiological pathways.
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Affiliation(s)
- Sami Agus
- Yeditepe University, Faculty of Medicine, Department of Physiology, Istanbul, Turkey
| | - Yavuz Yavuz
- Yeditepe University, Faculty of Medicine, Department of Physiology, Istanbul, Turkey
| | - Deniz Atasoy
- University of Iowa, Carver College of Medicine, Department of Neuroscience and Pharmacology, Iowa City, IA, USA
| | - Bayram Yilmaz
- Yeditepe University, Faculty of Medicine, Department of Physiology, Istanbul, Turkey
- Izmir Biomedicine and Genome Center, Izmir, Turkey
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3
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Moore AM, Novak AG, Lehman MN. KNDy Neurons of the Hypothalamus and Their Role in GnRH Pulse Generation: an Update. Endocrinology 2023; 165:bqad194. [PMID: 38170643 PMCID: PMC10768882 DOI: 10.1210/endocr/bqad194] [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: 10/23/2023] [Revised: 12/21/2023] [Accepted: 12/22/2023] [Indexed: 01/05/2024]
Abstract
There is considerable evidence that synchronized activity within a reciprocally connected population of cells in the arcuate nucleus (ARC) coexpressing kisspeptin, neurokinin B (NKB), and dynorphin (KNDy cells) is crucial for the generation of gonadotrophin-releasing hormone (GnRH) pulses in mammals. The initial "KNDy hypothesis" proposed that pulsatile GnRH secretion is elicited by episodic kisspeptin release from KNDy cells following synchronized activation and termination of the population by NKB and dynorphin, respectively. Since then, the role of KNDy cells as a critical component of the pulse generator has been further supported by studies at the single-cell level, demonstrating that the population is both necessary and sufficient for pulsatility. In addition, there have been considerable modifications and expansion of the original hypothesis, including work demonstrating the critical role of glutamate in synchronization of the KNDy cell network, functional interactions with other ARC subpopulations, and the existence of species differences in the role of dynorphin in pulse generation. Here we review these recent changes and discuss how the translation of these findings has led to the development of new therapies for disorders related to pulse generation. We also outline critical gaps in knowledge that are currently limiting the application of KNDy research in the clinic, particularly regarding the role of dynorphin in pulse generation in primates.
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Affiliation(s)
- Aleisha M Moore
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
- Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
| | - Alyssa G Novak
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
- Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
| | - Michael N Lehman
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
- Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
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4
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Nagae M, Yamada K, Enomoto Y, Kometani M, Tsuchida H, Panthee A, Nonogaki M, Matsunaga N, Takizawa M, Matsuzaki S, Hirabayashi M, Inoue N, Tsukamura H, Uenoyama Y. Conditional Oprk1-dependent Kiss1 deletion in kisspeptin neurons caused estrogen-dependent LH pulse disruption and LH surge attenuation in female rats. Sci Rep 2023; 13:20495. [PMID: 37993510 PMCID: PMC10665460 DOI: 10.1038/s41598-023-47222-5] [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] [Received: 07/05/2023] [Accepted: 11/10/2023] [Indexed: 11/24/2023] Open
Abstract
The gonadotropin-releasing hormone (GnRH) pulse and surge are considered to be generated by arcuate kisspeptin/neurokinin B/dynorphin A (KNDy) neurons and anteroventral periventricular nucleus (AVPV) kisspeptin neurons, respectively, in female rodents. The majority of KNDy and AVPV kisspeptin neurons express κ-opioid receptors (KORs, encoded by Oprk1) in female rodents. Thus, this study aimed to investigate the effect of a conditional Oprk1-dependent Kiss1 deletion in kisspeptin neurons on the luteinizing hormone (LH) pulse/surge and fertility using Kiss1-floxed/Oprk1-Cre rats, in which Kiss1 was deleted in cells expressing or once expressed the Oprk1/Cre. The Kiss1-floxed/Oprk1-Cre female rats, with Kiss1 deleted in a majority of KNDy neurons, showed normal puberty while having a one-day longer estrous cycle and fewer pups than Kiss1-floxed controls. Notably, ovariectomized (OVX) Kiss1-floxed/Oprk1-Cre rats showed profound disruption of LH pulses in the presence of a diestrous level of estrogen but showed apparent LH pulses without estrogen treatment. Furthermore, Kiss1-floxed/Oprk1-Cre rats, with Kiss1 deleted in approximately half of AVPV kisspeptin neurons, showed a lower peak of the estrogen-induced LH surge than controls. These results suggest that arcuate and AVPV kisspeptin neurons expressing or having expressed Oprk1 have a role in maintaining normal GnRH pulse and surge generation, the normal length of the estrous cycle, and the normal offspring number in female rats.
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Affiliation(s)
- Mayuko Nagae
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
- Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan
| | - Koki Yamada
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Yuki Enomoto
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Mari Kometani
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Hitomi Tsuchida
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Arvinda Panthee
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Miku Nonogaki
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Nao Matsunaga
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Marina Takizawa
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Sena Matsuzaki
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Masumi Hirabayashi
- Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan
| | - Naoko Inoue
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Hiroko Tsukamura
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
| | - Yoshihisa Uenoyama
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
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5
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Morris PG, Herbison AE. Mechanism of Arcuate Kisspeptin Neuron Synchronization in Acute Brain Slices From Female Mice. Endocrinology 2023; 164:bqad167. [PMID: 37936337 PMCID: PMC10652333 DOI: 10.1210/endocr/bqad167] [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: 08/01/2023] [Revised: 10/27/2023] [Accepted: 11/01/2023] [Indexed: 11/09/2023]
Abstract
The mechanism by which arcuate kisspeptin (ARNKISS) neurons co-expressing glutamate, neurokinin B, and dynorphin intermittently synchronize their activity to drive pulsatile hormone secretion remains unclear in females. In order to study spontaneous synchronization within the ARNKISS neuron network, acute brain slices were prepared from adult female Kiss1-GCaMP6 mice. Analysis of both spontaneous synchronizations and those driven by high frequency stimulation of individual ARNKISS neurons revealed that the network exhibits semi-random emergent excitation dependent upon glutamate signaling through AMPA receptors. No role for NMDA receptors was identified. In contrast to male mice, ongoing tachykinin receptor tone within the slice operated to promote spontaneous synchronizations in females. As previously observed in males, we found that ongoing dynorphin transmission in the slice did not contribute to synchronization events. These observations indicate that a very similar AMPA receptor-dependent mechanism underlies ARNKISS neuron synchronizations in the female mouse supporting the "glutamate two-transition" model for kisspeptin neuron synchronization. However, a potentially important sex difference appears to exist with a more prominent facilitatory role for tachykinin transmission in the female.
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Affiliation(s)
- Paul G Morris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Allan E Herbison
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
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Yamada K, Nagae M, Mano T, Tsuchida H, Hazim S, Goto T, Sanbo M, Hirabayashi M, Inoue N, Uenoyama Y, Tsukamura H. Sex difference in developmental changes in visualized Kiss1 neurons in newly generated Kiss1-Cre rats. J Reprod Dev 2023; 69:227-238. [PMID: 37518187 PMCID: PMC10602768 DOI: 10.1262/jrd.2023-019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/19/2023] [Indexed: 08/01/2023] Open
Abstract
Hypothalamic kisspeptin neurons are master regulators of mammalian reproduction via direct stimulation of gonadotropin-releasing hormone and consequent gonadotropin release. Here, we generated novel Kiss1 (kisspeptin gene)-Cre rats and investigated the developmental changes and sex differences in visualized Kiss1 neurons of Kiss1-Cre-activated tdTomato reporter rats. First, we validated Kiss1-Cre rats by generating Kiss1-expressing cell-specific Kiss1 knockout (Kiss1-KpKO) rats, which were obtained by crossing the current Kiss1-Cre rats with Kiss1-floxed rats. The resulting male Kiss1-KpKO rats lacked Kiss1 expression in the brain and exhibited hypogonadotropic hypogonadism, similar to the hypogonadal phenotype of global Kiss1 KO rats. Histological analysis of Kiss1 neurons in Kiss1-Cre-activated tdTomato reporter rats revealed that tdTomato signals in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) were not affected by estrogen, and that tdTomato signals in the ARC, AVPV, and medial amygdala (MeA) were sexually dimorphic. Notably, neonatal AVPV tdTomato signals were detected only in males, but a larger number of tdTomato-expressing cells were detected in the AVPV and ARC, and a smaller number of cells in the MeA was detected in females than in males at postpuberty. These findings suggest that Kiss1-visualized rats can be used to examine the effect of estrogen feedback mechanisms on Kiss1 expression in the AVPV and ARC. Moreover, the Kiss1-Cre and Kiss1-visualized rats could be valuable tools for further detailed analyses of sexual differentiation in the brain and the physiological role of kisspeptin neurons across the brain in rats.
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Affiliation(s)
- Koki Yamada
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Mayuko Nagae
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Tetsuya Mano
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Hitomi Tsuchida
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Safiullah Hazim
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Teppei Goto
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
- Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Aichi 444-8787, Japan
| | - Makoto Sanbo
- Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Aichi 444-8787, Japan
| | - Masumi Hirabayashi
- Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Aichi 444-8787, Japan
| | - Naoko Inoue
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Yoshihisa Uenoyama
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
| | - Hiroko Tsukamura
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Aichi 464-8601, Japan
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7
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Mansano NDS, Vieira HR, Araujo-Lopes R, Szawka RE, Donato J, Frazao R. Fasting Modulates GABAergic Synaptic Transmission to Arcuate Kisspeptin Neurons in Female Mice. Endocrinology 2023; 164:bqad150. [PMID: 37793082 DOI: 10.1210/endocr/bqad150] [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: 06/20/2023] [Revised: 09/28/2023] [Accepted: 10/02/2023] [Indexed: 10/06/2023]
Abstract
It is well-established that the hypothalamic-pituitary-gonadal (HPG) axis is suppressed due to negative energy balance. However, less information is available on whether kisspeptin neuronal activity contributes to fasting-induced responses. In the present study, female and male mice were fasted for 24 hours or provided food ad libitum (fed group) to determine whether acute fasting is sufficient to modulate kisspeptin neuronal activity. In female mice, fasting attenuated luteinizing hormone (LH) and prolactin (PRL) serum levels and increased follicle-stimulating hormone levels compared with the fed group. In contrast, fasting did not affect gonadotropin or PRL secretion in male mice. By measuring genes related to LH pulse generation in micropunches obtained from the arcuate nucleus of the hypothalamus (ARH), we observed that fasting reduced Kiss1 mRNA levels in female and male mice. In contrast, Pdyn expression was upregulated only in fasted female mice, whereas no changes in the Tac2 mRNA levels were observed in both sexes. Interestingly, the frequency and amplitude of the GABAergic postsynaptic currents recorded from ARH kisspeptin neurons (ARHKisspeptin) were reduced in 24-hour fasted female mice but not in males. Additionally, neuropeptide Y induced a hyperpolarization in the resting membrane potential of ARHKisspeptin neurons of fed female mice but not in males. Thus, the response of ARHKisspeptin neurons to fasting is sexually dependent with a female bias, associated with changes in gonadotropins and PRL secretion. Our findings suggest that GABAergic transmission to ARHKisspeptin neurons modulates the activity of the HPG axis during situations of negative energy balance.
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Affiliation(s)
- Naira da Silva Mansano
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Anatomia, São Paulo, SP 05508-000, Brazil
| | - Henrique Rodrigues Vieira
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Anatomia, São Paulo, SP 05508-000, Brazil
| | - Roberta Araujo-Lopes
- Universidade Federal de Minas Gerais, Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Belo Horizonte, MG 31270-901, Brazil
| | - Raphael Escorsim Szawka
- Universidade Federal de Minas Gerais, Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Belo Horizonte, MG 31270-901, Brazil
| | - Jose Donato
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Fisiologia e Biofísica, São Paulo, SP 05508-000, Brazil
| | - Renata Frazao
- Universidade de Sao Paulo, Instituto de Ciencias Biomedicas, Departamento de Anatomia, São Paulo, SP 05508-000, Brazil
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Voigt C, Gahr M, Bennett NC. Differential regulation of Kiss1 gene expression by oestradiol in the hypothalamus of the female Damaraland mole-rat, an induced ovulator. Gen Comp Endocrinol 2023; 341:114334. [PMID: 37302764 DOI: 10.1016/j.ygcen.2023.114334] [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: 02/08/2023] [Revised: 04/25/2023] [Accepted: 06/06/2023] [Indexed: 06/13/2023]
Abstract
Kisspeptin, a product of the Kiss1 gene is considered a potent stimulator of gonadotropin release, by interacting with its receptor, the G protein-coupled receptor 54. Kiss1 neurons are known to mediate the positive and negative feedback effects of oestradiol on GnRH neurons that control the pulsatile and surge secretion of GnRH. While in spontaneously ovulating mammals the GnRH/LH surge is initiated by a rise in ovarian oestradiol secreted from maturing follicles, in induced ovulators, the primary trigger is the mating stimulus. Damaraland mole rats (Fukomys damarensis) are cooperatively breeding, subterranean rodents that exhibit induced ovulation. We have previously described in this species the distribution and differential expression pattern of Kiss1-expressing neurons in the hypothalamus of males and females. Here we examine whether oestradiol (E2) regulates the hypothalamic Kiss1 expression in a similar way as described for spontaneously ovulating rodent species. By means of in situ hybridisation, we measured Kiss1 mRNA among groups of ovary-intact, ovariectomized (OVX) and OVX females treated with E2 (OVX + E2). In the arcuate nucleus (ARC), Kiss1 expression increased after ovariectomy and decreased with E2 treatment. In the preoptic region, Kiss1 expression after gonadectomy was similar to the level of wild-caught gonad-intact controls, but was dramatically upregulated with E2 treatment. The data suggest that, similar to other species, Kiss1 neurons in the ARC, which are inhibited by E2, play a role in the negative feedback control on GnRH release. The exact role of the Kiss1 neuron population in the preoptic region, which is stimulated by E2, remains to be determined.
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Affiliation(s)
- Cornelia Voigt
- Department of Zoology and Entomology, University of Pretoria, 0028 Pretoria, South Africa.
| | - Manfred Gahr
- Department of Behavioural Neurobiology, Max Planck Institute for Biological Intelligence, D-82319 Seewiesen, Germany.
| | - Nigel C Bennett
- Department of Zoology and Entomology, University of Pretoria, 0028 Pretoria, South Africa.
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Uenoyama Y, Tsukamura H. KNDy neurones and GnRH/LH pulse generation: Current understanding and future aspects. J Neuroendocrinol 2023; 35:e13285. [PMID: 37232103 DOI: 10.1111/jne.13285] [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: 01/04/2023] [Revised: 03/31/2023] [Accepted: 04/26/2023] [Indexed: 05/27/2023]
Abstract
Uncovering the central mechanism underlying mammalian reproduction is warranted to develop new therapeutic approaches for reproductive disorders in humans and domestic animals. The present study focused on the role of arcuate kisspeptin neurones (also known as KNDy neurones) as an intrinsic gonadotropin-releasing hormone (GnRH) pulse generator, which plays a fundamental role in mammalian reproduction via the stimulation of pituitary gonadotropin synthesis and release and thereby in gametogenesis and steroidogenesis in the gonads of mammals. We also discuss the mechanism that inhibits pulsatile GnRH/gonadotropin release under a negative energy balance, considering that reproductive disorders often occur during malnutrition in humans and livestock.
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Affiliation(s)
| | - Hiroko Tsukamura
- Laboratory of Animal Reproduction, Nagoya University, Nagoya, Japan
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10
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Uenoyama Y, Inoue N, Tsukamura H. Kisspeptin and lactational anestrus: Current understanding and future prospects. Peptides 2023; 166:171026. [PMID: 37230188 DOI: 10.1016/j.peptides.2023.171026] [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: 03/03/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 05/27/2023]
Abstract
Lactational anestrus, characterized by the suppression of pulsatile gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) release, would be a strategic adaptation to ensure survival by avoiding pregnancy during lactation in mammals. In the present article, we first provide a current understanding of the central regulation of reproduction in mammals, i.e., a fundamental role of arcuate kisspeptin neurons in mammalian reproduction by driving GnRH/LH pulses. Second, we discuss the central mechanism inhibiting arcuate Kiss1 (encoding kisspeptin) expression and GnRH/LH pulses during lactation with a focus on suckling stimulus, negative energy balance due to milk production, and the role of circulating estrogen in rats. We also discuss upper regulators that control arcuate kisspeptin neurons in rats during the early and late lactation periods based on the findings obtained by a lactating rat model. Finally, we discuss potential reproductive technology for the improvement of reproductive performance in milking cows.
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Affiliation(s)
- Yoshihisa Uenoyama
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
| | - Naoko Inoue
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Hiroko Tsukamura
- Laboratory of Animal Reproduction, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
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11
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Goto T, Hagihara M, Miyamichi K. Dynamics of pulsatile activities of arcuate kisspeptin neurons in aging female mice. eLife 2023; 12:82533. [PMID: 37223988 DOI: 10.7554/elife.82533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 05/09/2023] [Indexed: 05/26/2023] Open
Abstract
Reproductive senescence is broadly observed across mammalian females, including humans, eventually leading to a loss of fertility. The pulsatile secretion of gonadotropin-releasing hormone (GnRH), which is essential for gonad function, is primarily controlled by kisspeptin neurons in the hypothalamic arcuate nucleus (ARCkiss), the pulse generator of GnRH. The pulsatility of GnRH release, as assessed by the amount of circulating gonadotropin, is markedly reduced in aged animals, suggesting that the malfunctions of ARCkiss may be responsible for reproductive aging and menopause-related disorders. However, the activity dynamics of ARCkiss during the natural transition to reproductive senescence remain unclear. Herein, we introduce chronic in vivo Ca2+ imaging of ARCkiss in female mice by fiber photometry to monitor the synchronous episodes of ARCkiss (SEskiss), a known hallmark of GnRH pulse generator activity, from the fully reproductive to acyclic phase over 1 year. During the reproductive phase, we find that not only the frequency, but also the intensities and waveforms of individual SEskiss, vary depending on the stage of the estrus cycle. During the transition to reproductive senescence, the integrity of SEskiss patterns, including the frequency and waveforms, remains mostly unchanged, whereas the intensities tend to decline. These data illuminate the temporal dynamics of ARCkiss activities in aging female mice. More generally, our findings demonstrate the utility of fiber-photometry-based chronic imaging of neuroendocrine regulators in the brain to characterize aging-associated malfunction.
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Affiliation(s)
- Teppei Goto
- Laboratory for Comparative Connectomics, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Mitsue Hagihara
- Laboratory for Comparative Connectomics, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Kazunari Miyamichi
- Laboratory for Comparative Connectomics, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
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12
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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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13
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Ivanova D, O'Byrne KT. Optogenetics studies of kisspeptin neurons. Peptides 2023; 162:170961. [PMID: 36731655 DOI: 10.1016/j.peptides.2023.170961] [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: 11/07/2022] [Revised: 01/12/2023] [Accepted: 01/25/2023] [Indexed: 02/01/2023]
Abstract
Optical systems and genetic engineering technologies have made it possible to control neurons and unravel neuronal circuit behavior with high temporal and spatial resolution. The application of optogenetic strategies to understand the physiology of kisspeptin neuronal circuits has evolved in recent years among the neuroendocrine community. Kisspeptin neurons are fundamentally involved in controlling mammalian reproduction but also are implicated in numerous other physiological processes, including but not limited to feeding, energy expenditure, core body temperature and behavior. We conducted a review aiming to shed light on the novel findings obtained from in vitro and in vivo optogenetic studies interrogating kisspeptin neuronal circuits to date. Understanding the function of kisspeptin networks in the brain can greatly inform a wide range of clinical studies investigating infertility treatments, gender identity, metabolic disorders, hot flushes and psychosexual disorders.
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Affiliation(s)
- Deyana Ivanova
- Department of Women and Children's Health, Faculty of Life Science and Medicine, King's College London, UK.
| | - Kevin T O'Byrne
- Department of Women and Children's Health, Faculty of Life Science and Medicine, King's College London, UK
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14
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Mechanism of kisspeptin neuron synchronization for pulsatile hormone secretion in male mice. Cell Rep 2023; 42:111914. [PMID: 36640343 DOI: 10.1016/j.celrep.2022.111914] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/31/2022] [Accepted: 12/13/2022] [Indexed: 01/04/2023] Open
Abstract
The mechanism by which arcuate nucleus kisspeptin (ARNKISS) neurons co-expressing glutamate, neurokinin B, and dynorphin intermittently synchronize their activity to generate pulsatile hormone secretion remains unknown. An acute brain slice preparation maintaining synchronized ARNKISS neuron burst firing was used alongside in vivo GCaMP GRIN lens microendoscope and fiber photometry imaging coupled with intra-ARN microinfusion. Studies in intact and gonadectomized male mice revealed that ARNKISS neuron synchronizations result from near-random emergent network activity within the population and that this was critically dependent on local glutamate-AMPA signaling. Whereas neurokinin B operated to potentiate glutamate-generated synchronizations, dynorphin-kappa opioid tone within the network served as a gate for synchronization initiation. These observations force a departure from the existing "KNDy hypothesis" for ARNKISS neuron synchronization. A "glutamate two-transition" mechanism is proposed to underlie synchronizations in this key hypothalamic central pattern generator driving mammalian fertility.
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15
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Ivanova D, Li XF, McIntyre C, O’Byrne KT. Posterodorsal Medial Amygdala Urocortin-3, GABA, and Glutamate Mediate Suppression of LH Pulsatility in Female Mice. Endocrinology 2022; 164:6852761. [PMID: 36445688 PMCID: PMC9761574 DOI: 10.1210/endocr/bqac196] [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: 07/08/2022] [Revised: 11/20/2022] [Accepted: 11/22/2022] [Indexed: 11/30/2022]
Abstract
The posterodorsal subnucleus of the medial amygdala (MePD) is an upstream modulator of the hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-adrenal (HPA) axes. Inhibition of MePD urocortin-3 (Ucn3) neurons prevents psychological stress-induced suppression of luteinizing hormone (LH) pulsatility while blocking the stress-induced elevations in corticosterone (CORT) secretion in female mice. We explore the neurotransmission and neural circuitry suppressing the gonadotropin-releasing hormone (GnRH) pulse generator by MePD Ucn3 neurons and we further investigate whether MePD Ucn3 efferent projections to the hypothalamic paraventricular nucleus (PVN) control CORT secretion and LH pulsatility. Ucn3-cre-tdTomato female ovariectomized (OVX) mice were unilaterally injected with adeno-associated virus (AAV)-channelrhodopsin 2 (ChR2) and implanted with optofluid cannulae targeting the MePD. We optically activated Ucn3 neurons in the MePD with blue light at 10 Hz and monitored the effect on LH pulses. Next, we combined optogenetic stimulation of MePD Ucn3 neurons with pharmacological antagonism of GABAA or GABAB receptors with bicuculline or CGP-35348, respectively, as well as a combination of NMDA and AMPA receptor antagonists, AP5 and CNQX, respectively, and observed the effect on pulsatile LH secretion. A separate group of Ucn3-cre-tdTomato OVX mice with 17β-estradiol replacement were unilaterally injected with AAV-ChR2 in the MePD and implanted with fiber-optic cannulae targeting the PVN. We optically stimulated the MePD Ucn3 efferent projections in the PVN with blue light at 20 Hz and monitored the effect on CORT secretion and LH pulses. We reveal for the first time that activation of Ucn3 neurons in the MePD inhibits GnRH pulse generator frequency via GABA and glutamate signaling within the MePD, while MePD Ucn3 projections to the PVN modulate the HPG and HPA axes.
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Affiliation(s)
- Deyana Ivanova
- Correspondence: Deyana Ivanova, PhD, Department of Women and Children's Health, School of Life Course and Population Sciences, Faculty of Life Science and Medicine, King's College London, 2.92W Hodgkin Building, Guy's Campus, London SE1 1UL, UK. ; or Kevin T. O’Byrne, PhD, Department of Women and Children's Health, School of Life Course and Population Sciences, Faculty of Life Science and Medicine, King's College London, 2.92W Hodgkin Building, Guy's Campus, London SE1 1UL, UK.
| | - Xiao-Feng Li
- Department of Women and Children's Health, School of Life Course and Population Sciences, Faculty of Life Science and Medicine, King's College London, London SE1 1UL, UK
| | | | - Kevin T O’Byrne
- Correspondence: Deyana Ivanova, PhD, Department of Women and Children's Health, School of Life Course and Population Sciences, Faculty of Life Science and Medicine, King's College London, 2.92W Hodgkin Building, Guy's Campus, London SE1 1UL, UK. ; or Kevin T. O’Byrne, PhD, Department of Women and Children's Health, School of Life Course and Population Sciences, Faculty of Life Science and Medicine, King's College London, 2.92W Hodgkin Building, Guy's Campus, London SE1 1UL, UK.
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16
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Plain Z, Voliotis M, McArdle CA, Tsaneva-Atanasova K. Modelling KNDy neurons and gonadotropin-releasing hormone pulse generation. CURRENT OPINION IN ENDOCRINE AND METABOLIC RESEARCH 2022; 27:100407. [PMID: 36632147 PMCID: PMC9823092 DOI: 10.1016/j.coemr.2022.100407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The pulsatile release of gonadotropin-releasing hormone (GnRH) and its frequency are crucial for healthy reproductive function. To understand what drives GnRH pulses, a combination of experimental and mathematical modelling approaches has been used. Early work focussed on the possibility that GnRH pulse generation is an intrinsic feature of GnRH neurons, with autocrine feedback generating pulsatility. However, there is now ample evidence suggesting that a network of upstream neurons secreting kisspeptin, neurokinin-B and dynorphin are the source of this GnRH pulse generator. The interplay of slow positive and negative feedback via neurokinin-B and dynorphin, respectively, allows the network to act as a relaxation oscillator, driving pulsatile secretion of kisspeptin, and consequently, of GnRH and LH. Here, we review the mathematical modelling approaches exploring both scenarios and suggest that with pulsatile GnRH secretion driven by the KNDy pulse generator, autocrine feedback still has the potential to modulate GnRH output.
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Affiliation(s)
- Zoe Plain
- Department of Mathematics and Living Systems Institute, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Margaritis Voliotis
- Department of Mathematics and Living Systems Institute, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK,Corresponding author: Voliotis, Margaritis
| | | | - Krasimira Tsaneva-Atanasova
- Department of Mathematics and Living Systems Institute, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
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17
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Zheng Y, Zhang Q, Jing L, Fei Y, Zhao H. The Effects of Chronic Lead Exposure on Testicular Development of Japanese Quail (Coturnix japonica): Histopathological Damages, Oxidative Stress, Steroidogenesis Disturbance, and Hypothalamus-Pituitary-Testis Axis Disruption. Biol Trace Elem Res 2022; 201:3446-3460. [PMID: 36210404 DOI: 10.1007/s12011-022-03436-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/27/2022] [Indexed: 11/25/2022]
Abstract
Lead (Pb) becomes a global public health concern for its high toxicology. Birds are sensitive to environmental pollution and Pb contamination exerts multiple negative influences on bird life. Pb also impacts on avian reproductive system. Thus, in this study, we attempted to determine toxicological effects and possible mechanistic pathways of Pb on avian testicular development by using the model species-Japanese quail (Coturnix japonica). Male quail chicks of 1-week-old were exposed to 0, 50, 500, and 1000 ppm Pb concentrations in drinking water for 5 weeks when reaching sexual maturation. The results showed that high Pb doses (500 and 1000 ppm) induced testis atrophy and cloacal gland shrinkage. Microstructural damages of both hypothalamus and testis indicated the disruption of the hypothalamus-pituitary-gonadal (HPG) axis by Pb exposure. The decrease of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and testosterone (T) may also imply HPG axis disruption. Moreover, excess testicular oxidative damages featured by increasing reactive oxygen species (ROS) and malondialdehyde (MDA) and decreasing catalase (CAT), glutathione (GSH), superoxide dismutase (SOD), glutathione-S-transferase (GST), and total antioxidant capacity (T-AOC) indicated increasing risks of reproductive dysfunction by Pb. Furthermore, increasing apoptosis and upregulation of gene expression associated with cell death suggested testicular abnormal development. In addition, molecular signaling involved with steroidogenesis in the testis was disturbed by Pb treatment. The study showed that Pb could impair testicular development and reproductive function by morphological and histological injury, hormone suppression, oxidative stress, cell death, and HPG axis disruption.
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Affiliation(s)
- Ying Zheng
- College of Life Sciences, Shaanxi Normal University, No. 620, West Chang'an Avenue, Chang'an District, Xi'an, Shaanxi, 710119, People's Republic of China
| | - Qingyu Zhang
- College of Life Sciences, Shaanxi Normal University, No. 620, West Chang'an Avenue, Chang'an District, Xi'an, Shaanxi, 710119, People's Republic of China
| | - Lingyang Jing
- College of Life Sciences, Shaanxi Normal University, No. 620, West Chang'an Avenue, Chang'an District, Xi'an, Shaanxi, 710119, People's Republic of China
| | - Yifan Fei
- College of Life Sciences, Shaanxi Normal University, No. 620, West Chang'an Avenue, Chang'an District, Xi'an, Shaanxi, 710119, People's Republic of China
| | - Hongfeng Zhao
- College of Life Sciences, Shaanxi Normal University, No. 620, West Chang'an Avenue, Chang'an District, Xi'an, Shaanxi, 710119, People's Republic of China.
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18
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Affiliation(s)
- Michael N Lehman
- Brain Health Research Institute, Kent State University, Kent, OH, USA.
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19
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Kreisman MJ, McCosh RB, Breen KM. A Modified Ultra-Sensitive ELISA for Measurement of LH in Mice. Endocrinology 2022; 163:6649011. [PMID: 35869782 PMCID: PMC9337274 DOI: 10.1210/endocr/bqac109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Indexed: 12/25/2022]
Abstract
A major obstacle to monitoring pulsatile luteinizing hormone (LH) secretion in mice has been an assay with sufficient sensitivity in small blood volumes. In 2013, Steyn and colleagues published a highly sensitive enzyme-linked immunosorbent assay (ELISA) that overcame this barrier by coupling a duo of LH antibodies effective in accurately measuring LH in 4-µL whole-blood aliquots. To address the unavailability of the original detection antibody, AFP240580Rb, we validated a replacement detection antibody, biotinylated-5303 SPRN-5, to be used within the established ELISA. This modified LH ELISA demonstrated a minimum detection limit of 0.0028 ng/mL and a limit of quantification of 0.0333 ng/mL or 0.0666 ng/mL in diluted whole-blood samples of volume 6.4 µL (1:10) or 3.2 µL (1:20), respectively. Detection antibody 5303 SPRN-5 demonstrated parallelism, high precision, and accuracy across the standard curve. LH concentrations in comparison assays, using either 5303 SPRN-5 or AFP240580Rb, were highly correlated (R2 = 0.9829) and demonstrated LH pulse profiles from gonadectomized mice that were nearly superimposable. Pulsatile LH secretion was demonstrated in gonad-intact males and diestrous females and basal LH levels measured with 5303 SPRN-5 were approximately 5-fold higher than the limit of quantification. In addition, we document utility of this new LH ELISA to accurately measure LH in whole blood or serum across multiple sampling sites, as well as in pituitary extracts, LβT2 cells, or media. In summary, the modified LH ELISA described here is highly effective in measuring LH across a range of sample types and small volumes in mice.
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Affiliation(s)
- Michael J Kreisman
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, California 92093-0674, USA
| | - Richard B McCosh
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, California 92093-0674, USA
| | - Kellie M Breen
- Correspondence: Kellie M. Breen Church, PhD, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, 9500 Gilman Dr, MC 0674, La Jolla, CA 92093-0674, USA.
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20
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Moore AM. Impaired steroid hormone feedback in polycystic ovary syndrome: Evidence from preclinical models for abnormalities within central circuits controlling fertility. Clin Endocrinol (Oxf) 2022; 97:199-207. [PMID: 35349177 DOI: 10.1111/cen.14711] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/09/2022] [Accepted: 02/18/2022] [Indexed: 12/24/2022]
Abstract
Polycystic ovary syndrome (PCOS) is the most common endocrinopathy and cause of infertility in women of reproductive age worldwide. Despite diagnostic features of anovulation, polycystic ovarian morphology, and high androgen secretion indicating the syndrome are the result of ovarian dysfunction, alterations to central neuroendocrine circuits that control reproductive capacity may drive PCOS symptoms. Resistance of gonadotrophin-releasing hormone (GnRH) neurons in the hypothalamus to inhibition by sex steroid hormone-negative feedback leads to a rapid frequency of pulsatile gonadotrophin secretion, which, in turn, drives the ovarian features of the disease. As GnRH neurons do not express steroid hormone receptors, impaired negative feedback is hypothesized to occur within an upstream network that controls GnRH pulse generation. This review will discuss the latest work from preclinical animal models of PCOS used to dissect the specific central mechanisms involved in impaired steroid hormone feedback. In particular, this review will focus on research that indicates neurons in the arcuate nucleus of the hypothalamus that express Kisspeptin, Neurokinin B and Dynorphin (KNDy cells) or γ-aminobutyric acid are targets of androgen-mediated impairment of steroid hormone feedback. Finally, this review will explore the development of therapeutic agents targeting neurons that control LH pulse frequency to resolve PCOS symptoms in the clinic.
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Affiliation(s)
- Aleisha M Moore
- Department of Biological Sciences, Brain Health Research Institute, Kent State University, Kent, Ohio, USA
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21
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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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22
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Stincic TL, Kelly MJ. Estrogenic regulation of reproduction and energy homeostasis by a triumvirate of hypothalamic arcuate neurons. J Neuroendocrinol 2022; 34:e13145. [PMID: 35581942 DOI: 10.1111/jne.13145] [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: 12/18/2021] [Revised: 03/31/2022] [Accepted: 04/15/2022] [Indexed: 11/29/2022]
Abstract
Pregnancy is energetically demanding and therefore, by necessity, reproduction and energy balance are inextricably linked. With insufficient or excessive energy stores a female is liable to suffer complications during pregnancy or produce unhealthy offspring. Gonadotropin-releasing hormone neurons are responsible for initiating both the pulsatile and subsequent surge release of luteinizing hormone to control ovulation. Meticulous work has identified two hypothalamic populations of kisspeptin (Kiss1) neurons that are critical for this pattern of release. The involvement of the hypothalamus is unsurprising because its quintessential function is to couple the endocrine and nervous systems, coordinating energy balance and reproduction. Estrogens, more specifically 17β-estradiol (E2 ), orchestrate the activity of a triumvirate of hypothalamic neurons within the arcuate nucleus (ARH) that govern the physiological underpinnings of these behavioral dynamics. Arising from a common progenitor pool, these cells differentiate into ARH kisspeptin, pro-opiomelanocortin (POMC), and agouti related peptide/neuropeptide Y (AgRP) neurons. Although the excitability of all these subpopulations is subject to genomic and rapid estrogenic regulation, Kiss1 neurons are the most sensitive, reflecting their integral function in female fertility. Based on the premise that E2 coordinates autonomic functions around reproduction, we review recent findings on how Kiss1 neurons interact with gonadotropin-releasing hormone, AgRP and POMC neurons, as well as how the rapid membrane-initiated and intracellular signaling cascades activated by E2 in these neurons are critical for control of homeostatic functions supporting reproduction. In particular, we highlight how Kiss1 and POMC neurons conspire to inhibit AgRP neurons and diminish food motivation in service of reproductive success.
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Affiliation(s)
- Todd L Stincic
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR, USA
| | - Martin J Kelly
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR, USA
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA
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23
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Campbell RE, Coolen LM, Hoffman GE, Hrabovszky E. Highlights of neuroanatomical discoveries of the mammalian gonadotropin-releasing hormone system. J Neuroendocrinol 2022; 34:e13115. [PMID: 35502534 PMCID: PMC9232911 DOI: 10.1111/jne.13115] [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: 01/14/2022] [Revised: 02/09/2022] [Accepted: 03/01/2022] [Indexed: 11/17/2022]
Abstract
The anatomy and morphology of gonadotropin-releasing hormone (GnRH) neurons makes them both a joy and a challenge to investigate. They are a highly unique population of neurons given their developmental migration into the brain from the olfactory placode, their relatively small number, their largely scattered distribution within the rostral forebrain, and, in some species, their highly varied individual anatomical characteristics. These unique features have posed technological hurdles to overcome and promoted fertile ground for the establishment and use of creative approaches. Historical and more contemporary discoveries defining GnRH neuron anatomy remain critical in shaping and challenging our views of GnRH neuron function in the regulation of reproductive function. We begin this review with a historical overview of anatomical discoveries and developing methodologies that have shaped our understanding of the reproductive axis. We then highlight significant discoveries across specific groups of mammalian species to address some of the important comparative aspects of GnRH neuroanatomy. Lastly, we touch on unresolved questions and opportunities for future neuroanatomical research on this fascinating and important population of neurons.
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Affiliation(s)
- Rebecca E. Campbell
- Centre for Neuroendocrinology and Department of Physiology, School of Biomedical SciencesUniversity of OtagoDunedinNew Zealand
| | - Lique M. Coolen
- Department of Biological SciencesKent State UniversityKentOhioUSA
| | | | - Erik Hrabovszky
- Laboratory of Reproductive NeurobiologyInstitute of Experimental MedicineBudapestHungary
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24
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Xie Q, Kang Y, Zhang C, Xie Y, Wang C, Liu J, Yu C, Zhao H, Huang D. The Role of Kisspeptin in the Control of the Hypothalamic-Pituitary-Gonadal Axis and Reproduction. Front Endocrinol (Lausanne) 2022; 13:925206. [PMID: 35837314 PMCID: PMC9273750 DOI: 10.3389/fendo.2022.925206] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 05/30/2022] [Indexed: 01/07/2023] Open
Abstract
The discovery of kisspeptin as a critical central regulatory factor of GnRH release has given people a novel understanding of the neuroendocrine regulation in human reproduction. Kisspeptin activates the signaling pathway by binding to its receptor kisspeptin receptor (KISS1R) to promote GnRH secretion, thereby regulating the hypothalamic-pituitary-gonadal axis (HPG) axis. Recent studies have shown that kisspeptin neurons located in arcuate nucleus (ARC) co-express neurokinin B (NKB) and dynorphin (Dyn). Such neurons are called KNDy neurons. KNDy neurons participate in the positive and negative feedback of estrogen to GnRH secretion. In addition, kisspeptin is a key factor in the initiation of puberty, and also regulates the processes of female follicle development, oocyte maturation, and ovulation through the HPG axis. In male reproduction, kisspeptin also plays an important role, getting involved in the regulation of Leydig cells, spermatogenesis, sperm functions and reproductive behaviors. Mutations in the KISS1 gene or disorders of the kisspeptin/KISS1R system may lead to clinical symptoms such as idiopathic hypogonadotropic hypogonadism (iHH), central precocious puberty (CPP) and female infertility. Understanding the influence of kisspeptin on the reproductive axis and related mechanisms will help the future application of kisspeptin in disease diagnosis and treatment. In this review, we critically appraise the role of kisspeptin in the HPG axis, including its signaling pathways, negative and positive feedback mechanisms, and its control on female and male reproduction.
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Affiliation(s)
- Qinying Xie
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yafei Kang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chenlu Zhang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ye Xie
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chuxiong Wang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiang Liu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Caiqian Yu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hu Zhao
- Department of Human Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Donghui Huang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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25
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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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