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Radomsky T, Anderson RC, Millar RP, Newton CL. Restoring function to inactivating G protein-coupled receptor variants in the hypothalamic-pituitary-gonadal axis 1. J Neuroendocrinol 2024:e13418. [PMID: 38852954 DOI: 10.1111/jne.13418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 03/30/2024] [Accepted: 05/15/2024] [Indexed: 06/11/2024]
Abstract
G protein-coupled receptors (GPCRs) are central to the functioning of the hypothalamic-pituitary-gonadal axis (HPG axis) and include the rhodopsin-like GPCR family members, neurokinin 3 receptor, kappa-opioid receptor, kisspeptin 1 receptor, gonadotropin-releasing hormone receptor, and the gonadotropin receptors, luteinizing hormone/choriogonadotropin receptor and follicle-stimulating hormone receptor. Unsurprisingly, inactivating variants of these receptors have been implicated in a spectrum of reproductive phenotypes, including failure to undergo puberty, and infertility. Clinical induction of puberty in patients harbouring such variants is possible, but restoration of fertility is not always a realisable outcome, particularly for those patients suffering from primary hypogonadism. Thus, novel pharmaceuticals and/or a fundamental change in approach to treating these patients are required. The increasing wealth of data describing the effects of coding-region genetic variants on GPCR function has highlighted that the majority appear to be dysfunctional as a result of misfolding of the encoded receptor protein, which, in turn, results in impaired receptor trafficking through the secretory pathway to the cell surface. As such, these intracellularly retained receptors may be amenable to 'rescue' using a pharmacological chaperone (PC)-based approach. PCs are small, cell permeant molecules hypothesised to interact with misfolded intracellularly retained proteins, stabilising their folding and promoting their trafficking through the secretory pathway. In support of the use of this approach as a viable therapeutic option, it has been observed that many rescued variant GPCRs retain at least a degree of functionality when 'rescued' to the cell surface. In this review, we examine the GPCR PC research landscape, focussing on the rescue of inactivating variant GPCRs with important roles in the HPG axis, and describe what is known regarding the mechanisms by which PCs restore trafficking and function. We also discuss some of the merits and obstacles associated with taking this approach forward into a clinical setting.
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Affiliation(s)
- Tarryn Radomsky
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Ross C Anderson
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
- Faculty of Health Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- School of Medicine, University of St Andrews, St Andrews, UK
| | - Claire L Newton
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
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Aerts EG, Griesgraber MJ, Shuping SL, Bowdridge EC, Hardy SL, Goodman RL, Nestor CC, Hileman SM. The effect of NK3-Saporin injection within the arcuate nucleus on puberty, the LH surge, and the response to Senktide in female sheep†. Biol Reprod 2024; 110:275-287. [PMID: 37930247 DOI: 10.1093/biolre/ioad147] [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: 08/16/2023] [Revised: 10/09/2023] [Accepted: 10/24/2023] [Indexed: 11/07/2023] Open
Abstract
The timing of puberty onset is reliant on increased gonadotropin-releasing hormone (GnRH). This elicits a corresponding increase in luteinizing hormone (LH) due to a lessening of sensitivity to the inhibitory actions of estradiol (E2). The mechanisms underlying the increase in GnRH release likely involve a subset of neurons within the arcuate (ARC) nucleus of the hypothalamus that contain kisspeptin, neurokinin B (NKB), and dynorphin (KNDy neurons). We aimed to determine if KNDy neurons in female sheep are critical for: timely puberty onset; the LH surge; and the response to an intravenous injection of the neurokinin-3 receptor (NK3R) agonist, senktide. Prepubertal ewes received injections aimed at the ARC containing blank-saporin (control, n = 5) or NK3-saporin (NK3-SAP, n = 6) to ablate neurons expressing NK3R. Blood samples taken 3/week for 65 days following surgery were assessed for progesterone to determine onset of puberty. Control ewes exhibited onset of puberty at 33.2 ± 3.9 days post sampling initiation, whereas 5/6 NK3-SAP treated ewes didn't display an increase in progesterone. After an artificial LH surge protocol, surge amplitude was lower in NK3-SAP ewes. Finally, ewes were treated with senktide to determine if an LH response was elicited. LH pulses were evident in both groups in the absence of injections, but the response to senktide vs saline was similar between groups. These results show that KNDy cells are necessary for timely puberty onset and for full expresson of the LH surge. The occurrence of LH pulses in NK3-SAP treated ewes may indicate a recovery from an apulsatile state.
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Affiliation(s)
- Eliana G Aerts
- Department of Physiology, Pharmacology and Toxicology, Morgantown, WV 26506, USA
| | - Max J Griesgraber
- Department of Physiology, Pharmacology and Toxicology, Morgantown, WV 26506, USA
| | - Sydney L Shuping
- Department of Animal Science, North Carolina State University, Raleigh, NC 27695, USA
| | | | - Steven L Hardy
- Department of Physiology, Pharmacology and Toxicology, Morgantown, WV 26506, USA
| | - Robert L Goodman
- Department of Physiology, Pharmacology and Toxicology, Morgantown, WV 26506, USA
- Department of Neuroscience, West Virginia University, Morgantown, WV 26506, USA
| | - Casey C Nestor
- Department of Animal Science, North Carolina State University, Raleigh, NC 27695, USA
| | - Stanley M Hileman
- Department of Physiology, Pharmacology and Toxicology, Morgantown, WV 26506, USA
- Department of Neuroscience, West Virginia University, Morgantown, WV 26506, USA
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Ye J, Yan X, Zhang W, Lu J, Xu S, Li X, Qin P, Gong X, Liu Y, Ling Y, Li Y, Zhang Y, Fang F. Integrative proteomic and phosphoproteomic analysis in the female goat hypothalamus to study the onset of puberty. BMC Genomics 2023; 24:621. [PMID: 37853328 PMCID: PMC10583467 DOI: 10.1186/s12864-023-09705-7] [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: 03/14/2023] [Accepted: 09/28/2023] [Indexed: 10/20/2023] Open
Abstract
BACKGROUND Puberty marks the end of childhood and achieve sexual maturation and fertility. The role of hypothalamic proteins in regulating puberty onset is unclear. We performed a comprehensive differential proteomics and phosphoproteomics analysis in prepubertal and pubertal goats to determine the roles of hypothalamic proteins and phosphoproteins during the onset of puberty. RESULTS We used peptide and posttranslational modifications peptide quantification and statistical analyses, and identified 69 differentially expressed proteins from 5,057 proteins and 576 differentially expressed phosphopeptides from 1574 phosphorylated proteins. Combined proteomic and phosphoproteomics, 759 correlated proteins were identified, of which 5 were differentially expressed only at the protein level, and 201 were only differentially expressed at the phosphoprotein level. Pathway enrichment analyses revealed that the majority of correlated proteins were associated with glycolysis/gluconeogenesis, Fc gamma R-mediated phagocytosis, focal adhesion, GABAergic synapse, and Rap1 signaling pathway. These pathways are related to cell proliferation, neurocyte migration, and promoting the release of gonadotropin-releasing hormone in the hypothalamus. CTNNB1 occupied important locations in the protein-protein interaction network and is involved in focal adhesion. CONCLUSION The results demonstrate that the proteins differentially expression only at the protein level or only differentially expressed at the phosphoprotein level and their related signalling pathways are crucial in regulating puberty in goats. These differentially expressed proteins and phosphorylated proteins may constitute the proteomic backgrounds between the two different stages.
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Affiliation(s)
- Jing Ye
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
- Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 230036, Hefei, Anhui, China
| | - Xu Yan
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
- Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 230036, Hefei, Anhui, China
| | - Wei Zhang
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
| | - Juntai Lu
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
| | - Shuangshuang Xu
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
| | - Xiaoqian Li
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
| | - Ping Qin
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
- Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 230036, Hefei, Anhui, China
| | - Xinbao Gong
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
- Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 230036, Hefei, Anhui, China
| | - Ya Liu
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
- Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 230036, Hefei, Anhui, China
| | - Yinghui Ling
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
- Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 230036, Hefei, Anhui, China
| | - Yunsheng Li
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China
- Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 230036, Hefei, Anhui, China
| | - Yunhai Zhang
- Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 230036, Hefei, Anhui, China
| | - Fugui Fang
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, 230036, Hefei, Anhui, China.
- Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, 230036, Hefei, Anhui, China.
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Goodman RL, Moore AM, Onslow K, Hileman SM, Hardy SL, Bowdridge EC, Walters BA, Agus S, Griesgraber MJ, Aerts EG, Lehman MN, Coolen LM. Lesions of KNDy and Kiss1R Neurons in the Arcuate Nucleus Produce Different Effects on LH Pulse Patterns in Female Sheep. Endocrinology 2023; 164:bqad148. [PMID: 37776515 PMCID: PMC10587900 DOI: 10.1210/endocr/bqad148] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/02/2023]
Abstract
The current model for the synchronization of GnRH neural activity driving GnRH and LH pulses proposes that a set of arcuate (ARC) neurons that contain kisspeptin, neurokinin B, and dynorphin (KNDy neurons) is the GnRH pulse generator. This study tested the functional role of ovine KNDy neurons in pulse generation and explored the roles of nearby Kiss1 receptor (Kiss1R)-containing cells using lesions produced with saporin (SAP) conjugates. Injection of NK3-SAP ablated over 90% of the KNDy cells, while Kiss-SAP (saporin conjugated to kisspeptin-54) lesioned about two-thirds of the Kiss1R population without affecting KNDy or GnRH cell number. Both lesions produced a dramatic decrease in LH pulse amplitude but had different effects on LH pulse patterns. NK3-SAP increased interpulse interval, but Kiss-SAP did not. In contrast, Kiss-SAP disrupted the regular hourly occurrence of LH pulses, but NK3-SAP did not. Because Kiss1R is not expressed in KNDy cells, HiPlex RNAScope was used to assess the colocalization of 8 neurotransmitters and 3 receptors in ARC Kiss1R-containing cells. Kiss1R cells primarily contained transcript markers for GABA (68%), glutamate (28%), ESR1 (estrogen receptor-α) mRNA, and OPRK1 (kappa opioid receptor) mRNA. These data support the conclusion that KNDy neurons are essential for GnRH pulses in ewes, whereas ARC Kiss1R cells are not but do maintain the amplitude and regularity of GnRH pulses. We thus propose that in sheep, ARC Kiss1R neurons form part of a positive feedback circuit that reinforces the activity of the KNDy neural network, with GABA or glutamate likely being involved.
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Affiliation(s)
- Robert L Goodman
- Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, USA
| | - Aleisha M Moore
- Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Kayla Onslow
- Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Stanley M Hileman
- Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, USA
| | - Steve L Hardy
- Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, USA
| | - Elizabeth C Bowdridge
- Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, USA
| | - Burgundy A Walters
- Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Sami Agus
- Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Max J Griesgraber
- Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, USA
| | - Eliana G Aerts
- Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, USA
| | - Michael N Lehman
- Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Lique M Coolen
- Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
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5
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Nestor CC, Merkley CM, Lehman MN, Hileman SM, Goodman RL. KNDy neurons as the GnRH pulse generator: Recent studies in ruminants. Peptides 2023; 164:171005. [PMID: 36990389 PMCID: PMC10164117 DOI: 10.1016/j.peptides.2023.171005] [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: 12/28/2022] [Revised: 03/10/2023] [Accepted: 03/24/2023] [Indexed: 03/29/2023]
Abstract
This review considers three aspects of recent work on the role of KNDy neurons in GnRH pulse generation in ruminants. First, work on basic mechanisms of pulse generation includes several tests of this hypothesis, all of which support it, and evidence that Kiss1r-containing neurons form a positive feedback circuit with the KNDy neural network that strengthen the activity of this network. The second section on pathways mediating external inputs focuses on the influence of nutrition and photoperiod, and describes the evidence supporting roles for proopiomelanocortin (POMC) and agouti-related peptide (AgRP) afferents to KNDy cells in each of these. Finally, we review studies exploring the potential applications of manipulating signaling by kisspeptin, and the other KNDy peptides, to control reproductive function in domestic animals and conclude that, although these approaches show some promise, they do not have major advantages over current practices at this time.
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Affiliation(s)
- Casey C Nestor
- Department of Animal Science, North Carolina State University, Raleigh, NC, USA
| | | | - Michael N Lehman
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Stanley M Hileman
- Department of Physiology, Pharmacology, and Toxicology, West Virginia University, Morgantown, WV, USA
| | - Robert L Goodman
- Department of Physiology, Pharmacology, and Toxicology, West Virginia University, Morgantown, WV, USA.
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Garza V, West SM, Cardoso RC. Review: Gestational and postnatal nutritional effects on the neuroendocrine control of puberty and subsequent reproductive performance in heifers. Animal 2023; 17 Suppl 1:100782. [PMID: 37567667 DOI: 10.1016/j.animal.2023.100782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 03/13/2023] [Accepted: 03/17/2023] [Indexed: 08/13/2023] Open
Abstract
Pubertal attainment is an intricate biological process that involves maturation of the reproductive neuroendocrine axis and increased pulsatile release of gonadotropin-releasing hormone (GnRH) and luteinizing hormone. Nutrition is a critical environmental factor controlling the timing of puberty attainment. Nutrient restriction during early postnatal development delays puberty, whereas increased feed intake and adiposity during this period hasten pubertal maturation by imprinting the hypothalamus. Moreover, the dam's nutrition during gestation can program the neuroendocrine system in the developing fetus and has the potential to advance or delay puberty in the offspring. Leptin, a hormone produced primarily by adipose cells, plays an important role in communicating energy status to the brain and regulating sexual maturation. Leptin's regulation of GnRH release is mediated by an upstream neuronal network since GnRH neurons do not contain the leptin receptor. Two groups of neurons located in the arcuate nucleus of the hypothalamus that express neuropeptide Y (NPY), an orexigenic peptide, and alpha melanocyte-stimulating hormone (αMSH), an anorexigenic peptide, are central elements of the neural circuitry that relay inhibitory (NPY) and excitatory (αMSH) inputs to GnRH neurons. Moreover, KNDy neurons, neurons in the arcuate nucleus that co-express kisspeptin, neurokinin B (NKB), and dynorphin, also play a role in the metabolic regulation of puberty. Our studies in beef heifers demonstrate that increased rates of BW gain during early postweaning (4-9 mo of age) result in reduced expression of NPY mRNA, increased expression of proopiomelanocortin and kisspeptin receptor mRNA, reduced NPY inhibitory inputs to GnRH neurons, and increased excitatory αMSH inputs to KNDy neurons. Finally, our most recent data demonstrate that nutrition of the cow during the last two trimesters of gestation can also induce transcriptional and structural changes in hypothalamic neurocircuitries in the heifer progeny that likely persist long-term after birth. Managerial approaches, such as supplementation of the dam during gestation (fetal programming), creep feeding, early weaning, and stair-step nutritional regimens have been developed to exploit brain plasticity and advance pubertal maturation in heifers.
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Affiliation(s)
- Viviana Garza
- Department of Animal Science, Texas A&M University, 2471 TAMU, College Station, TX 77843, USA
| | - Sarah M West
- Department of Animal Science, Texas A&M University, 2471 TAMU, College Station, TX 77843, USA
| | - Rodolfo C Cardoso
- Department of Animal Science, Texas A&M University, 2471 TAMU, College Station, TX 77843, USA.
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Bulut F, Kacar E, Bilgin B, Hekim MG, Keleştemur MM, Sahin Z, Ayar A, Ozcan M. Crosstalk between kisspeptin and gonadotropin-inhibitory hormone in the silence of puberty: preclinical evidence from a calcium signaling study. J Recept Signal Transduct Res 2022; 42:608-613. [PMID: 36137227 DOI: 10.1080/10799893.2022.2125014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Kisspeptin and gonadotropin-inhibitory hormone (GnIH) are among suggested neuroendocrine modulators of reproductive function. Intracellular calcium signaling is a critical component in the regulation of a variety of physiological and pathological processes including neurotransmitter release, and, therefore, can be used as signaling indicator for investigating the involvement of kisspeptin, GnIH, and gonadotropin-releasing hormone (GnRH) release. Hence, this study investigated the effects of kisspeptin and GnIH on calcium signaling using immortalized hypothalamic cells (rHypoE-8) as a model. Kisspeptin neurons were loaded with the ratiometric calcium dye (Fura-2 AM, 1 μmol) and intracellular free calcium ([Ca2+]i) responses were quantified using digital fluorescence imaging system. Kisspeptin-10 (100, 300, and 1000 nM) caused a significant increase in [Ca2+]i in rHypoE-8 cells (n = 58, n = 64, and n = 49, respectively, p < 0.001). The kisspeptin receptor antagonist, P234, inhibited the calcium responses to kisspeptin (p < 0.001, n = 32). GnIH (100 and 1000 nM), alone, did not cause any significant change in the mean basal [Ca2+]i levels in kisspeptin cells, but GnIH attenuated the kisspeptin-evoked [Ca2+]i transients (n = 47, p < 0.001). This novel findings of [Ca2+]i signaling in in vitro setting implicate that kisspeptin and GnIH may exert their effects on hypothalamus-pituitary-gonadal (HPG) axis by modulating kisspeptin neurons. These results also implicate that kisspeptin neurons may have an autocrine regulation.
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Affiliation(s)
- Ferah Bulut
- Department of Biophysics, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Emine Kacar
- Department of Physiology, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Batuhan Bilgin
- Department of Biophysics, Faculty of Medicine, Firat University, Elazig, Turkey
| | | | | | - Zafer Sahin
- Department of Physiology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey
| | - Ahmet Ayar
- Department of Physiology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey
| | - Mete Ozcan
- Department of Biophysics, Faculty of Medicine, Firat University, Elazig, Turkey
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Sheep as a model for neuroendocrinology research. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 189:1-34. [PMID: 35595346 DOI: 10.1016/bs.pmbts.2022.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Animal models remain essential to understand the fundamental mechanisms of physiology and pathology. Particularly, the complex and dynamic nature of neuroendocrine cells of the hypothalamus make them difficult to study. The neuroendocrine systems of the hypothalamus are critical for survival and reproduction, and are highly conserved throughout vertebrate evolution. Their roles in controlling body metabolism, growth and body composition, stress, electrolyte balance, and reproduction, have been intensively studied, and have yielded groundbreaking discoveries. Many of these discoveries would not have been feasible without the use of the domestic sheep (Ovis aries). The sheep has been used for decades to study the neuroendocrine systems of the hypothalamus and has become a model for human neuroendocrinology. The aim of this chapter is to review some of the profound biomedical discoveries made possible by the use of sheep. The advantages and limitations of sheep as a neuroendocrine model will be discussed. While no animal model can perfectly recapitulate a human disease or condition, sheep are invaluable for enabling manipulations not possible in human subjects and isolating physiologic variables to garner insight into neuroendocrinology and associated pathologies.
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Goodman RL, Herbison AE, Lehman MN, Navarro VM. Neuroendocrine control of gonadotropin-releasing hormone: Pulsatile and surge modes of secretion. J Neuroendocrinol 2022; 34:e13094. [PMID: 35107859 PMCID: PMC9948945 DOI: 10.1111/jne.13094] [Citation(s) in RCA: 35] [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] [Received: 11/23/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 11/28/2022]
Abstract
The concept that different systems control episodic and surge secretion of gonadotropin-releasing hormone (GnRH) was well established by the time that GnRH was identified and formed the framework for studies of the physiological roles of GnRH, and later kisspeptin. Here, we focus on recent studies identifying the neural mechanisms underlying these two modes of secretion, with an emphasis on their core components. There is now compelling data that kisspeptin neurons in the arcuate nucleus that also contain neurokinin B (NKB) and dynorphin (i.e., KNDy cells) and their projections to GnRH dendrons constitute the GnRH pulse generator in mice and rats. There is also strong evidence for a similar role for KNDy neurons in sheep and goats, and weaker data in monkeys and humans. However, whether KNDy neurons act on GnRH dendrons and/or GnRH soma and dendrites that are found in the mediobasal hypothalamus (MBH) of these species remains unclear. The core components of the GnRH/luteinising hormone surge consist of an endocrine signal that initiates the process and a neural trigger that drives GnRH secretion during the surge. In all spontaneous ovulators, the core endocrine signal is a rise in estradiol secretion from the maturing follicle(s), with the site of estrogen positive feedback being the rostral periventricular kisspeptin neurons in rodents and neurons in the MBH of sheep and primates. There is considerable species variations in the neural trigger, with three major classes. First, in reflex ovulators, this trigger is initiated by coitus and carried to the hypothalamus by neural or vascular pathways. Second, in rodents, there is a time of day signal that originates in the suprachiasmatic nucleus and activates rostral periventricular kisspeptin neurons and GnRH soma and dendrites. Finally, in sheep nitric oxide-producing neurons in the ventromedial nucleus, KNDy neurons and rostral kisspeptin neurons all appear to participate in driving GnRH release during the surge.
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Affiliation(s)
- Robert L. Goodman
- Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV, USA
| | - Allan E. Herbison
- Department of Physiology Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Michael N. Lehman
- Brain Health Research Institute, Kent State University, Kent, OH, USA
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Victor M. Navarro
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School and Department of Medicine, Boston, MA, USA
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Anderson RA, Millar RP. The roles of kisspeptin and neurokinin B in GnRH pulse generation in humans, and their potential clinical application. J Neuroendocrinol 2022; 34:e13081. [PMID: 34962670 DOI: 10.1111/jne.13081] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/22/2021] [Accepted: 12/14/2021] [Indexed: 12/22/2022]
Abstract
The delivery of gonadotropin-releasing hormone (GnRH) in a pulsatile mode to the gonadotropes has long been known to be essential for normal reproductive function. There have been numerous studies aimed at dissecting out the mechanisms underlying GnRH pulse generation. The discovery of kisspeptin as an upstream regulator of GnRH attracted the possibility that pulsatile kisspeptin governed the pulsatile secretion of GnRH. Subsequent studies have shown the importance of the neurokinin B (NKB) system in modulating kisspeptin secretion and this GnRH. A number of studies in laboratory rodents have supported this notion. By contrast, we present data from clinical studies in men and women, in a range of contexts, showing that continuous infusion of kisspeptin 10 at receptor-saturating levels gives rise to an increase in luteinizing hormone (LH) (GnRH) pulse frequency. This has been demonstrated in normal healthy and hypogonadal men, in normal women during the mid-cycle LH surge, in men and women with mutations in the genes encoding NKB or its receptor, neurokinin 3 receptor (NK3R), in women with polycystic ovary syndrome treated with NK3R antagonist, and in women treated with NK3R antagonist during the LH surge. These finds indicate that pulsatile secretion and action of kisspeptin on GnRH neurons is not required for the generation of LH (GnRH) pulses in humans. We also report that there is an absence of desensitization in humans exposed to continuous infusion of kisspeptin-10 at receptor-saturating concentrations over 22 h and briefly review GnRH, kisspeptin and NKB analogs and their clinical application.
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Affiliation(s)
- Richard A Anderson
- MRC Centre for Reproductive Health, Queens Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Robert P Millar
- Department of Immunology, Faculty of Health Sciences, Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa
- Department of Integrative Biomedical Sciences, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, Observatory, South Africa
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11
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León S, Fergani C, Talbi R, Maguire CA, Gerutshang A, Seminara SB, Navarro VM. Tachykinin Signaling Is Required for Induction of the Preovulatory Luteinizing Hormone Surge and Normal Luteinizing Hormone Pulses. Neuroendocrinology 2021; 111:542-554. [PMID: 32512561 PMCID: PMC7722126 DOI: 10.1159/000509222] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 06/08/2020] [Indexed: 12/16/2022]
Abstract
Tachykinins (neurokinin A [NKA], neurokinin B [NKB], and substance P [SP]) are important components of the neuroendocrine control of reproduction by direct stimulation of Kiss1 neurons to control GnRH pulsatility, which is essential for reproduction. Despite this role of tachykinins in successful reproduction, knockout (KO) mice for Tac1 (NKA/SP) and Tac2 (NKB) genes are fertile, resembling the phenotype of human patients bearing NKB signaling mutations, who often reverse their hypogonadal phenotype. This suggests the existence of compensatory mechanisms among the different tachykinin ligand-receptor systems to maintain reproduction in the absence of one of them. In order to test this hypothesis, we generated complete tachykinin-deficient mice (Tac1/Tac2KO). Male mice displayed delayed puberty onset and decreased luteinizing hormone (LH) pulsatility (frequency and amplitude of LH pulses) but preserved fertility. However, females did not show signs of puberty onset (first estrus) within 45 days after vaginal opening, they displayed a low frequency (but normal amplitude) of LH pulses, and 80% of them remained infertile. Further evaluation identified a complete absence of the preovulatory LH surge in Tac1/Tac2KO females as well as in wild-type females treated with NKB or SP receptor antagonists. These data confirmed a fundamental role of tachykinins in the timing of puberty onset and LH pulsatility and uncovered a role of tachykinin signaling in facilitation of the preovulatory LH surge. Overall, these findings indicate that tachykinin signaling plays a dominant role in the control of ovulation, with potential implications as a pathogenic mechanism and a therapeutic target to improve reproductive outcomes in women with ovulation impairments.
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Affiliation(s)
- Silvia León
- Harvard Medical School, Boston, Massachusetts, USA
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Chrysanthi Fergani
- Harvard Medical School, Boston, Massachusetts, USA
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Rajae Talbi
- Harvard Medical School, Boston, Massachusetts, USA
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Caroline A Maguire
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Achi Gerutshang
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Stephanie B Seminara
- Harvard Medical School, Boston, Massachusetts, USA
- Harvard Reproductive Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Victor M Navarro
- Harvard Medical School, Boston, Massachusetts, USA,
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA,
- Harvard Program in Neuroscience, Boston, Massachusetts, USA,
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12
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Rietema SE, Hawken PAR, Scott CJ, Lehman MN, Martin GB, Smith JT. Arcuate nucleus kisspeptin response to increased nutrition in rams. Reprod Fertil Dev 2020; 31:1682-1691. [PMID: 31511141 DOI: 10.1071/rd19063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 06/16/2019] [Indexed: 11/23/2022] Open
Abstract
Rams respond to acute nutritional supplementation by increasing the frequency of gonadotrophin-releasing hormone (GnRH) pulses. Kisspeptin neurons may mediate the effect of environmental cues on GnRH secretion, so we tested whether the ram response to nutrition involves activation of kisspeptin neurons in the arcuate nucleus (ARC), namely kisspeptin, neurokin B, dynorphin (KNDy) neurons. Rams were given extra lupin grain with their normal ration. Blood was sampled before feeding, and continued until animals were killed for collection of brain tissue at 2 or 11h after supplementation. In supplemented rams, LH pulse frequency increased after feeding, whereas control animals showed no change. Within the caudal ARC, there were more kisspeptin neurons in supplemented rams than in controls and a higher proportion of kisspeptin cells coexpressed Fos, regardless of the time the rams were killed. There were more Fos cells in the mid-ARC and mid-dorsomedial hypothalamus of the supplemented compared with control rams. No effect of nutrition was found on kisspeptin expression in the rostral or mid-ARC, or on GnRH expression in the preoptic area. Kisspeptin neurons in the caudal ARC appear to mediate the increase in GnRH and LH production due to acute nutritional supplementation, supporting the hypothesised role of the KNDy neurons as the pulse generator for GnRH.
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Affiliation(s)
- S E Rietema
- School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - P A R Hawken
- School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - C J Scott
- School of Biomedical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, NSW 2678, Australia
| | - M N Lehman
- Brain Health Research Institute and Department of Biological Sciences, Kent State University, PO Box 5190, Kent, OH 44242-0001, USA
| | - G B Martin
- School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - J T Smith
- The School of Human Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia; and Corresponding author.
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13
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Tang C, Zhang J, Liu P, Zhou Y, Hu Q, Zhong Y, Wang X, Chen L. Chronic exposure to low dose of bisphenol A causes follicular atresia by inhibiting kisspeptin neurons in anteroventral periventricular nucleus in female mice. Neurotoxicology 2020; 79:164-176. [PMID: 32407858 DOI: 10.1016/j.neuro.2020.04.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 04/27/2020] [Accepted: 04/27/2020] [Indexed: 11/16/2022]
Abstract
Bisphenol-A (BPA) is an estrogenic chemical extensively used in industrial and household applications. The present study was conducted to investigate the effect of chronic exposure to BPA on the adult female neuroendocrine system. Herein, we found that expose of adult female mice to BPA (50 μg/kg) by oral gavage for 60 days (BPA mice) prolonged diestrus and decreased serum 17β-estradiol (E2) concentration by reducing the number of antral follicles and corpora luteum. In comparison with controls, the levels of serum luteinizing hormone (LH), follicle stimulating hormone (FSH), hypothalamic gonadotrophin releasing hormone (GnRH) and the expression of kisspeptin in anteroventral periventricular nucleus (AVPV) decreased in BPA mice, which could be reversed by injecting kisspeptin-10 (i.c.v.). Treatment with BPA or estrogen receptor α (ERα) antagonist MPP, but not ERβ antagonist PHTPP inhibited E2-induced AVPV-kisspeptin expression in ovariectomized mice. Use of ERα agonist PPT rather than ERβ agonist DPN enhanced AVPV-kisspepetin expression, which decreased after treatment with BPA. The amplitude of the proestrus LH surge decreased in mice exposed to BPA, but was recovered by administering kisspeptin-10. The present study provides in vivo evidence that chronic exposure to a low dose of BPA suppressed ERα-induced activation of AVPV-kisspeptin neurons, leading to prolonged diestrus and reduced ovulation in adult female mice.
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Affiliation(s)
- Chuanfeng Tang
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, China; State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Jia Zhang
- Sir Run Run Hospital, Nanjing Medical University, Nanjing, 211166, China
| | - Peiyu Liu
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
| | - Yu Zhou
- Department of Pharmacology, Nanjing Medical University, Nanjing, 211166, China
| | - Qiaoyun Hu
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
| | - Ying Zhong
- Department of Pharmacology, Nanjing Medical University, Nanjing, 211166, China
| | - Xiaoli Wang
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, China.
| | - Lei Chen
- Department of Physiology, Nanjing Medical University, Nanjing, 211166, China.
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14
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Minabe S, Nakamura S, Fukushima E, Sato M, Ikegami K, Goto T, Sanbo M, Hirabayashi M, Tomikawa J, Imamura T, Inoue N, Uenoyama Y, Tsukamura H, Maeda KI, Matsuda F. Inducible Kiss1 knockdown in the hypothalamic arcuate nucleus suppressed pulsatile secretion of luteinizing hormone in male mice. J Reprod Dev 2020; 66:369-375. [PMID: 32336702 PMCID: PMC7470898 DOI: 10.1262/jrd.2019-164] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Accumulating evidence suggests that kisspeptin-GPR54 signaling is indispensable for gonadotropin-releasing hormone (GnRH)/gonadotropin secretion and consequent reproductive functions in mammals. Conventional Kiss1 knockout (KO) mice and rats are reported to be infertile. To date, however, no study has investigated the effect of inducible central Kiss1 KO/knockdown on pulsatile gonadotropin release in male mammals. Here we report an in vivo analysis of inducible conditional Kiss1 knockdown male mice. The mice were generated by a bilateral injections of either adeno-associated virus (AAV) vectors driving Cre recombinase (AAV-Cre) or AAV vectors driving GFP (AAV-GFP, control) into the hypothalamic arcuate nucleus (ARC) of Kiss1-floxed male mice, in which exon 3 of the Kiss1 gene were floxed with loxP sites. Four weeks after the AAV-Cre injection, the mice showed a profound decrease in the both number of ARC Kiss1-expressing cells and the luteinizing hormone (LH) pulse frequency. Interestingly, pulsatile LH secretion was apparent 8 weeks after the AAV-Cre injection despite the suppression of ARC Kiss1 expression. The control Kiss1-floxed mice infected with AAV-GFP showed apparent LH pulses and Kiss1 expression in the ARC at both 4 and 8 weeks after the AAV-GFP injection. These results with an inducible conditional Kiss1 knockdown in the ARC of male mice suggest that ARC kisspeptin neurons are responsible for pulsatile LH secretion in male mice, and indicate the possibility of a compensatory mechanism that restores GnRH/LH pulse generation.
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Affiliation(s)
- Shiori Minabe
- Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Sho Nakamura
- Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Eri Fukushima
- Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Marimo Sato
- Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Kana Ikegami
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Teppei Goto
- Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Aichi 444-8787, Japan
| | - Makoto Sanbo
- Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Aichi 444-8787, Japan
| | - Masumi Hirabayashi
- Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Aichi 444-8787, Japan
| | - Junko Tomikawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Takuya Imamura
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Naoko Inoue
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Yoshihisa Uenoyama
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Hiroko Tsukamura
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Kei-Ichiro Maeda
- Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Fuko Matsuda
- Department of Veterinary Medical Sciences, The University of Tokyo, Tokyo 113-8657, Japan
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15
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Voliotis M, Li XF, De Burgh R, Lass G, Lightman SL, O'Byrne KT, Tsaneva-Atanasova K. The Origin of GnRH Pulse Generation: An Integrative Mathematical-Experimental Approach. J Neurosci 2019; 39:9738-9747. [PMID: 31645462 PMCID: PMC6891054 DOI: 10.1523/jneurosci.0828-19.2019] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/22/2019] [Accepted: 07/29/2019] [Indexed: 12/20/2022] Open
Abstract
Fertility critically depends on the gonadotropin-releasing hormone (GnRH) pulse generator, a neural construct comprised of hypothalamic neurons coexpressing kisspeptin, neurokoinin-B and dynorphin. Here, using mathematical modeling and in vivo optogenetics we reveal for the first time how this neural construct initiates and sustains the appropriate ultradian frequency essential for reproduction. Prompted by mathematical modeling, we show experimentally using female estrous mice that robust pulsatile release of luteinizing hormone, a proxy for GnRH, emerges abruptly as we increase the basal activity of the neuronal network using continuous low-frequency optogenetic stimulation. Further increase in basal activity markedly increases pulse frequency and eventually leads to pulse termination. Additional model predictions that pulsatile dynamics emerge from nonlinear positive and negative feedback interactions mediated through neurokinin-B and dynorphin signaling respectively are confirmed neuropharmacologically. Our results shed light on the long-elusive GnRH pulse generator offering new horizons for reproductive health and wellbeing.SIGNIFICANCE STATEMENT The gonadotropin-releasing hormone (GnRH) pulse generator controls the pulsatile secretion of the gonadotropic hormones LH and FSH and is critical for fertility. The hypothalamic arcuate kisspeptin neurons are thought to represent the GnRH pulse generator, since their oscillatory activity is coincident with LH pulses in the blood; a proxy for GnRH pulses. However, the mechanisms underlying GnRH pulse generation remain elusive. We developed a mathematical model of the kisspeptin neuronal network and confirmed its predictions experimentally, showing how LH secretion is frequency-modulated as we increase the basal activity of the arcuate kisspeptin neurons in vivo using continuous optogenetic stimulation. Our model provides a quantitative framework for understanding the reproductive neuroendocrine system and opens new horizons for fertility regulation.
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Affiliation(s)
- Margaritis Voliotis
- Department of Mathematics and Living Systems Institute, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom,
- The Engineering and Physical Sciences Research Council (EPSRC) Centre for Predictive Modelling in Healthcare, University of Exeter, Exeter EX4 4QJ, United Kingdom
| | - Xiao Feng Li
- Department of Women and Children's Health, School of Life Course Sciences, King's College London, London SE1 1UL, United Kingdom, and
| | - Ross De Burgh
- Department of Women and Children's Health, School of Life Course Sciences, King's College London, London SE1 1UL, United Kingdom, and
| | - Geffen Lass
- Department of Women and Children's Health, School of Life Course Sciences, King's College London, London SE1 1UL, United Kingdom, and
| | - Stafford L Lightman
- Henry Wellcome Laboratory for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol BS1 3NY, United Kingdom
| | - Kevin T O'Byrne
- Department of Women and Children's Health, School of Life Course Sciences, King's College London, London SE1 1UL, United Kingdom, and
| | - Krasimira Tsaneva-Atanasova
- Department of Mathematics and Living Systems Institute, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, United Kingdom,
- The Engineering and Physical Sciences Research Council (EPSRC) Centre for Predictive Modelling in Healthcare, University of Exeter, Exeter EX4 4QJ, United Kingdom
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16
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Terasawa E. Mechanism of pulsatile GnRH release in primates: Unresolved questions. Mol Cell Endocrinol 2019; 498:110578. [PMID: 31518609 PMCID: PMC6944307 DOI: 10.1016/j.mce.2019.110578] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 12/18/2022]
Abstract
The pulsatility of GnRH release is essential for reproductive function. The key events in reproductive function, such as puberty onset and ovulatory cycles, are regulated by the frequency and amplitude modulation of pulsatile GnRH release. Abnormal patterns of GnRH pulsatility are seen in association with disease states, such as polycystic ovarian syndrome and anorexia nervosa. Recent studies with physiological, track-tracing, optogenetic and electrophysiological recording experiments indicate that a group of kisspeptin neurons in the arcuate nucleus (ARC) of the hypothalamus are responsible for pulsatile GnRH release. Thus, the kisspeptin neuron in the ARC has been called the "GnRH pulse-generator." However, a few pieces of evidence do not quite fit into this concept. This article reviews some old works and discusses unresolved issues on the mechanism of GnRH pulse generation.
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Affiliation(s)
- Ei Terasawa
- AWisconsin National Primate Research Center, University of Wisconsin, Madison, WI, 53715, USA; Department of Pediatrics, University of Wisconsin, Madison, WI, 53706, USA.
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17
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Abdel-Fadeil MR, Abd Allah ES, Iraqy HM, Elgamal DA, Abdel-Ghani MA. Experimental obesity and diabetes reduce male fertility: Potential involvement of hypothalamic Kiss-1, pituitary nitric oxide, serum vaspin and visfatin. PATHOPHYSIOLOGY 2019; 26:181-189. [DOI: 10.1016/j.pathophys.2019.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/23/2019] [Accepted: 02/04/2019] [Indexed: 12/18/2022] Open
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18
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Plant TM. The neurobiological mechanism underlying hypothalamic GnRH pulse generation: the role of kisspeptin neurons in the arcuate nucleus. F1000Res 2019; 8. [PMID: 31297186 PMCID: PMC6600864 DOI: 10.12688/f1000research.18356.2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/20/2019] [Indexed: 01/21/2023] Open
Abstract
This review recounts the origins and development of the concept of the hypothalamic gonadotropin-releasing hormone (GnRH) pulse generator. It starts in the late 1960s when striking rhythmic episodes of luteinizing hormone secretion, as reflected by circulating concentrations of this gonadotropin, were first observed in monkeys and ends in the present day. It is currently an exciting time witnessing the application, primarily to the mouse, of contemporary neurobiological approaches to delineate the mechanisms whereby
Kiss1/NKB/Dyn (KNDy) neurons in the arcuate nucleus of the hypothalamus generate and time the pulsatile output of kisspeptin from their terminals in the median eminence that in turn dictates intermittent GnRH release and entry of this decapeptide into the primary plexus of the hypophysial portal circulation. The review concludes with an examination of questions that remain to be addressed.
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Affiliation(s)
- Tony M Plant
- Magee-Womens Research Institute, University of Pittsburgh, 204 Craft Avenue, Pittsburgh, PA 15213, USA
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19
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Plant TM. The neurobiological mechanism underlying hypothalamic GnRH pulse generation: the role of kisspeptin neurons in the arcuate nucleus. F1000Res 2019; 8:F1000 Faculty Rev-982. [PMID: 31297186 PMCID: PMC6600864 DOI: 10.12688/f1000research.18356.1] [Citation(s) in RCA: 30] [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] [Accepted: 06/20/2019] [Indexed: 03/22/2024] Open
Abstract
This review recounts the origins and development of the concept of the hypothalamic gonadotropin-releasing hormone (GnRH) pulse generator. It starts in the late 1960s when striking rhythmic episodes of luteinizing hormone secretion, as reflected by circulating concentrations of this gonadotropin, were first observed in monkeys and ends in the present day. It is currently an exciting time witnessing the application, primarily to the mouse, of contemporary neurobiological approaches to delineate the mechanisms whereby Kiss1/NKB/Dyn (KNDy) neurons in the arcuate nucleus of the hypothalamus generate and time the pulsatile output of kisspeptin from their terminals in the median eminence that in turn dictates intermittent GnRH release and entry of this decapeptide into the primary plexus of the hypophysial portal circulation. The review concludes with an examination of questions that remain to be addressed.
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Affiliation(s)
- Tony M. Plant
- Magee-Womens Research Institute, University of Pittsburgh, 204 Craft Avenue, Pittsburgh, PA 15213, USA
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20
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Sahin Z, Kelestimur H. RF9: May it be a new therapeutic option for hypogonadotropic hypogonadism? Med Hypotheses 2019; 128:54-57. [PMID: 31203909 DOI: 10.1016/j.mehy.2019.05.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 04/30/2019] [Accepted: 05/12/2019] [Indexed: 12/12/2022]
Abstract
Hypogonadotropic hypogonadism (secondary hypogonadism), congenital or acquired, is a form of hypogonadism that is due to problems with either the hypothalamus or pituitary gland affecting gonadotropin levels. Pulsatile secretion of gonadotropin-releasing hormone (GnRH) by hypothalamus is a primer step to initiate the release of pituitary gonadotropins. Kisspeptin and gonadotropin-inhibitory hormone (GnIH) are accepted as two major players in the activation and inhibition of GnRH regarding the neuroendocrine functioning of the hypothalamic pituitary gonadal axis. Kisspeptin is known as the most potent activator of GnRH. Regarding the inhibition of GnRH, RF-amide-related peptide-3 (RFRP-3) is accepted as the mammalian orthologue of GnIH in avian species. RF9 (1-adamantane carbonyl-Arg-Phe-NH2) is an antagonist of RFRP-3/GnIH receptor (neuropeptide FF receptor 1 (NPFFR1; also termed as GPR147). In recent years, several studies have indicated that RF9 activates GnRH neurons and gonadotropins in a kisspeptin receptor (Kiss1r, formerly known as GPR54) dependent manner. These results suggest that RF9 may have a bimodal function as both an RFRP-3 antagonist and a kisspeptin agonist or it may be a kiss1r agonist rather than an RFRP-3/GnIH receptor antagonist. These interactions are possible because Kisspeptin and GnIH are members of the RF-amide family, and both possibilities are not far from explaining the potent gonadotropin stimulating effects of RF9. Therefore, we hypothesize that RF9 may be a new therapeutic option for the hypogonadotropic hypogonadism due to its potent GnRH stimulating effects. A constant or repeated administration of RF9 provides a sustained increase in plasma gonadotrophin levels. However, applications in the same way with GnRH analogues and kisspeptin may result in desensitization of the gonadotropic axis. The reasons reported above contribute to our hypothesis that RF9 may be a good option in the GnRH stimulating as a kisspeptin agonist. We suggest that further studies are needed to elucidate the potential effects of RF9 in the treatment of the hypogonadotropic hypogonadism.
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Affiliation(s)
- Zafer Sahin
- Department of Physiology, Karadeniz Technical University, Trabzon, Turkey.
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21
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Liang S, Kinghorn AB, Voliotis M, Prague JK, Veldhuis JD, Tsaneva-Atanasova K, McArdle CA, Li RHW, Cass AEG, Dhillo WS, Tanner JA. Measuring luteinising hormone pulsatility with a robotic aptamer-enabled electrochemical reader. Nat Commun 2019; 10:852. [PMID: 30787284 PMCID: PMC6382769 DOI: 10.1038/s41467-019-08799-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 01/28/2019] [Indexed: 11/23/2022] Open
Abstract
Normal reproductive functioning is critically dependent on pulsatile secretion of luteinising hormone (LH). Assessment of LH pulsatility is important for the clinical diagnosis of reproductive disorders, but current methods are hampered by frequent blood sampling coupled to expensive serial immunochemical analysis. Here, we report the development and application of a Robotic APTamer-enabled Electrochemical Reader (RAPTER) electrochemical analysis system to determine LH pulsatility. Through selective evolution of ligands by exponential enrichment (SELEX), we identify DNA aptamers that bind specifically to LH and not to related hormones. The aptamers are integrated into electrochemical aptamer-based (E-AB) sensors on a robotic platform. E-AB enables rapid, sensitive and repeatable determination of LH concentration profiles. Bayesian Spectrum Analysis is applied to determine LH pulsatility in three distinct patient cohorts. This technology has the potential to transform the clinical care of patients with reproductive disorders and could be developed to allow real-time in vivo hormone monitoring.
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Affiliation(s)
- Shaolin Liang
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, SW7 2AZ, UK
- Department of Chemistry, Imperial College London, London, SW7 2AZ, UK
| | - Andrew B Kinghorn
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Margaritis Voliotis
- Department of Mathematics and Living Systems Institute, College of Engineering, Mathematics, and Physical Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Julia K Prague
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, SW7 2AZ, UK
| | - Johannes D Veldhuis
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Mayo Clinic, Rochester, MN 55905, MN, USA
| | - Krasimira Tsaneva-Atanasova
- Department of Mathematics and Living Systems Institute, College of Engineering, Mathematics, and Physical Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Craig A McArdle
- Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, BS1 3NY, UK
| | - Raymond H W Li
- Department of Obstetrics and Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Anthony E G Cass
- Department of Chemistry, Imperial College London, London, SW7 2AZ, UK.
| | - Waljit S Dhillo
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, SW7 2AZ, UK.
| | - Julian A Tanner
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
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22
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Scott CJ, Rose JL, Gunn AJ, McGrath BM. Kisspeptin and the regulation of the reproductive axis in domestic animals. J Endocrinol 2018; 240:JOE-18-0485.R1. [PMID: 30400056 DOI: 10.1530/joe-18-0485] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 10/09/2018] [Indexed: 11/08/2022]
Abstract
The control of reproductive processes involves the integration of a number of factors from the internal and external environment, with the final output signal of these processes being the pulsatile secretion of gonadotrophin releasing hormone (GnRH) from the hypothalamus. These factors include the feedback actions of sex steroids, feed intake and nutritional status, season/photoperiod, pheromones, age and stress. Understanding these factors and how they influence GnRH secretion and hence reproduction is important for the management of farm animals. There is evidence that the RF-amide neuropeptide, kisspeptin, may be involved in relaying the effects of these factors to the GnRH neurons. This paper will review the evidence from the common domestic animals (sheep, goats, cattle, horses and pigs), that kisspeptin neurons are i) regulated by the factors listed above, ii) contact GnRH neurons, and iii) involved in the regulation of GnRH/gonadotrophin secretion.
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Affiliation(s)
- Christopher J Scott
- C Scott, School of Biomedical Sciences, Charles Sturt University - Wagga Wagga Campus, Wagga Wagga, Australia
| | - Jessica L Rose
- J Rose, School of Biomedical Sciences, Charles Sturt University - Wagga Wagga Campus, Wagga Wagga, Australia
| | - Allan J Gunn
- A Gunn, School of Animal and Veterinary Sciences, Charles Sturt University - Wagga Wagga Campus, Wagga Wagga, Australia
| | - Briony M McGrath
- B McGrath, School of Biomedical Sciences, Charles Sturt University - Wagga Wagga Campus, Wagga Wagga, Australia
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23
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Moore AM, Coolen LM, Porter DT, Goodman RL, Lehman MN. KNDy Cells Revisited. Endocrinology 2018; 159:3219-3234. [PMID: 30010844 PMCID: PMC6098225 DOI: 10.1210/en.2018-00389] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 07/05/2018] [Indexed: 12/29/2022]
Abstract
In the past decade since kisspeptin/neurokinin B/dynorphin (KNDy) cells were first identified in the mammalian hypothalamus, a plethora of new research has emerged adding insights into the role of this neuronal population in reproductive neuroendocrine function, including the basis for GnRH pulse generation and the mechanisms underlying the steroid feedback control of GnRH secretion. In this mini-review, we provide an update of evidence regarding the roles of KNDy peptides and their postsynaptic receptors in producing episodic GnRH release and assess the relative contribution of KNDy neurons to the "GnRH pulse generator." In addition, we examine recent work investigating the role of KNDy neurons as mediators of steroid hormone negative feedback and review evidence for their involvement in the preovulatory GnRH/LH surge, taking into account species differences that exist among rodents, ruminants, and primates. Finally, we summarize emerging roles of KNDy neurons in other aspects of reproductive function and in nonreproductive functions and discuss critical unresolved questions in our understanding of KNDy neurobiology.
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Affiliation(s)
- Aleisha M Moore
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi
| | - Lique M Coolen
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi
- Department of Physics and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Danielle T Porter
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi
| | - Robert L Goodman
- Department of Physiology, Pharmacology, and Neuroscience, West Virginia University, Morgantown, West Virginia
| | - Michael N Lehman
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi
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24
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Harter CJL, Kavanagh GS, Smith JT. The role of kisspeptin neurons in reproduction and metabolism. J Endocrinol 2018; 238:R173-R183. [PMID: 30042117 DOI: 10.1530/joe-18-0108] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 06/13/2018] [Indexed: 02/06/2023]
Abstract
Kisspeptin is a neuropeptide with a critical role in the function of the hypothalamic-pituitary-gonadal (HPG) axis. Kisspeptin is produced by two major populations of neurons located in the hypothalamus, the rostral periventricular region of the third ventricle (RP3V) and arcuate nucleus (ARC). These neurons project to and activate gonadotrophin-releasing hormone (GnRH) neurons (acting via the kisspeptin receptor, Kiss1r) in the hypothalamus and stimulate the secretion of GnRH. Gonadal sex steroids stimulate kisspeptin neurons in the RP3V, but inhibit kisspeptin neurons in the ARC, which is the underlying mechanism for positive- and negative feedback respectively, and it is now commonly accepted that the ARC kisspeptin neurons act as the GnRH pulse generator. Due to kisspeptin's profound effect on the HPG axis, a focus of recent research has been on afferent inputs to kisspeptin neurons and one specific area of interest has been energy balance, which is thought to facilitate effects such as suppressing fertility in those with under- or severe over-nutrition. Alternatively, evidence is building for a direct role for kisspeptin in regulating energy balance and metabolism. Kiss1r-knockout (KO) mice exhibit increased adiposity and reduced energy expenditure. Although the mechanisms underlying these observations are currently unknown, Kiss1r is expressed in adipose tissue and potentially brown adipose tissue (BAT) and Kiss1rKO mice exhibit reduced energy expenditure. Recent studies are now looking at the effects of kisspeptin signalling on behaviour, with clinical evidence emerging of kisspeptin affecting sexual behaviour, further investigation of potential neuronal pathways are warranted.
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Affiliation(s)
- Campbell J L Harter
- School of Human SciencesThe University of Western Australia, Perth, Western Australia, Australia
| | - Georgia S Kavanagh
- School of Human SciencesThe University of Western Australia, Perth, Western Australia, Australia
| | - Jeremy T Smith
- School of Human SciencesThe University of Western Australia, Perth, Western Australia, Australia
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25
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Nestor CC, Bedenbaugh MN, Hileman SM, Coolen LM, Lehman MN, Goodman RL. Regulation of GnRH pulsatility in ewes. Reproduction 2018; 156:R83-R99. [PMID: 29880718 DOI: 10.1530/rep-18-0127] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/07/2018] [Indexed: 01/21/2023]
Abstract
Early work in ewes provided a wealth of information on the physiological regulation of pulsatile gonadotropin-releasing hormone (GnRH) secretion by internal and external inputs. Identification of the neural systems involved, however, was limited by the lack of information on neural mechanisms underlying generation of GnRH pulses. Over the last decade, considerable evidence supported the hypothesis that a group of neurons in the arcuate nucleus that contain kisspeptin, neurokinin B and dynorphin (KNDy neurons) are responsible for synchronizing secretion of GnRH during each pulse in ewes. In this review, we describe our current understanding of the neural systems mediating the actions of ovarian steroids and three external inputs on GnRH pulsatility in light of the hypothesis that KNDy neurons play a key role in GnRH pulse generation. In breeding season adults, estradiol (E2) and progesterone decrease GnRH pulse amplitude and frequency, respectively, by actions on KNDy neurons, with E2 decreasing kisspeptin and progesterone increasing dynorphin release onto GnRH neurons. In pre-pubertal lambs, E2 inhibits GnRH pulse frequency by decreasing kisspeptin and increasing dynorphin release, actions that wane as the lamb matures to allow increased pulsatile GnRH secretion at puberty. Less is known about mediators of undernutrition and stress, although some evidence implicates kisspeptin and dynorphin, respectively, in the inhibition of GnRH pulse frequency by these factors. During the anoestrus, inhibitory photoperiod acting via melatonin activates A15 dopaminergic neurons that innervate KNDy neurons; E2 increases dopamine release from these neurons to inhibit KNDy neurons and suppress the frequency of kisspeptin and GnRH release.
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Affiliation(s)
- Casey C Nestor
- Department of Animal Science, North Carolina State University, Raleigh, North Carolina, USA
| | - Michelle N Bedenbaugh
- Department of Physiology, Pharmacology and Neuroscience, West Virginia University, Morgantown, West Virginia, USA
| | - Stanley M Hileman
- Department of Physiology, Pharmacology and Neuroscience, West Virginia University, Morgantown, West Virginia, USA
| | - Lique M Coolen
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi, USA.,Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Michael N Lehman
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Robert L Goodman
- Department of Physiology, Pharmacology and Neuroscience, West Virginia University, Morgantown, West Virginia, USA
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