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Eraslan IM, Egberts-Brugman M, Read JL, Voglsanger LM, Samarasinghe RM, Hamilton L, Dhar P, Williams RJ, Walker LC, Ch'ng S, Lawrence AJ, Walker AJ, Dean OM, Gundlach AL, Smith CM. Neuroanatomical distribution of fluorophores within adult RXFP3 Cre-tdTomato/YFP mouse brain. Biochem Pharmacol 2024; 225:116265. [PMID: 38714277 DOI: 10.1016/j.bcp.2024.116265] [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: 01/14/2024] [Revised: 05/01/2024] [Accepted: 05/03/2024] [Indexed: 05/09/2024]
Abstract
Relaxin-family peptide 3 receptor (RXFP3) is activated by relaxin-3 in the brain to influence arousal and related functions, such as feeding and stress responses. Two transgenic mouse lines have recently been developed that co-express different fluorophores within RXFP3-expressing neurons: either yellow fluorescent protein (YFP; RXFP3-Cre/YFP mice) or tdTomato (RXFP3-Cre/tdTomato mice). To date, the characteristics of neurons that express RXFP3-associated fluorophores in these mice have only been investigated in the bed nucleus of the stria terminalis and the hypothalamic arcuate nucleus. To better determine the utility of these fluorophore-expressing mice for further research, we characterised the neuroanatomical distribution of fluorophores throughout the brain of these mice and compared this to the published distribution of Rxfp3 mRNA (detected by in situ hybridisation) in wildtype mice. Coronal sections of RXFP3-Cre/YFP (n = 8) and RXFP3-Cre/tdTomato (n = 8) mouse brains were imaged, and the density of fluorophore-expressing cells within various brain regions/nuclei was qualitatively assessed. Comparisons with our previously reported RXFP3 mRNA distribution revealed that of 212 brain regions that contained either fluorophore or RXFP3 mRNA, approximately half recorded densities that were within two qualitative measurements of each other (on a 9-point scale), including hippocampal dentate gyrus and amygdala subregions. However, many brain areas with likely non-authentic, false-positive, or false-negative fluorophore expression were also detected, including the cerebellum. Therefore, this study provides a guide to which brain regions should be prioritized for future study of RXFP3 in these mice, to better understand the neuroanatomy and function of this intriguing, neuronal peptide receptor.
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Affiliation(s)
- Izel M Eraslan
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Monique Egberts-Brugman
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Justin L Read
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Lara M Voglsanger
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Rasika M Samarasinghe
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Lee Hamilton
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Poshmaal Dhar
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Richard J Williams
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Leigh C Walker
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Sarah Ch'ng
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Andrew J Lawrence
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Adam J Walker
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Olivia M Dean
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia; The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Craig M Smith
- Faculty of Health, School of Medicine, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Waurn Ponds, Victoria 3216, Australia.
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The Relaxin-3 Receptor, RXFP3, Is a Modulator of Aging-Related Disease. Int J Mol Sci 2022; 23:ijms23084387. [PMID: 35457203 PMCID: PMC9027355 DOI: 10.3390/ijms23084387] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 12/12/2022] Open
Abstract
During the aging process our body becomes less well equipped to deal with cellular stress, resulting in an increase in unrepaired damage. This causes varying degrees of impaired functionality and an increased risk of mortality. One of the most effective anti-aging strategies involves interventions that combine simultaneous glucometabolic support with augmented DNA damage protection/repair. Thus, it seems prudent to develop therapeutic strategies that target this combinatorial approach. Studies have shown that the ADP-ribosylation factor (ARF) GTPase activating protein GIT2 (GIT2) acts as a keystone protein in the aging process. GIT2 can control both DNA repair and glucose metabolism. Through in vivo co-regulation analyses it was found that GIT2 forms a close coexpression-based relationship with the relaxin-3 receptor (RXFP3). Cellular RXFP3 expression is directly affected by DNA damage and oxidative stress. Overexpression or stimulation of this receptor, by its endogenous ligand relaxin 3 (RLN3), can regulate the DNA damage response and repair processes. Interestingly, RLN3 is an insulin-like peptide and has been shown to control multiple disease processes linked to aging mechanisms, e.g., anxiety, depression, memory dysfunction, appetite, and anti-apoptotic mechanisms. Here we discuss the molecular mechanisms underlying the various roles of RXFP3/RLN3 signaling in aging and age-related disorders.
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Gołyszny M, Obuchowicz E, Zieliński M. Neuropeptides as regulators of the hypothalamus-pituitary-gonadal (HPG) axis activity and their putative roles in stress-induced fertility disorders. Neuropeptides 2022; 91:102216. [PMID: 34974357 DOI: 10.1016/j.npep.2021.102216] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/21/2021] [Accepted: 10/05/2021] [Indexed: 11/24/2022]
Abstract
Neuropeptides being regulators of the hypothalamus-pituitary-adrenal (HPA) axis activity, also affect the function of the hypothalamus-pituitary-gonadal (HPG) axis by regulating gonadotrophin-releasing hormone (GnRH) secretion from hypothalamic neurons. Here, we review the available data on how neuropeptides affect HPG axis activity directly or indirectly via their influence on the HPA axis. The putative role of neuropeptides in stress-induced infertility, such as polycystic ovary syndrome, is also described. This review discusses both well-known neuropeptides (i.e., kisspeptin, Kp; oxytocin, OT; arginine-vasopressin, AVP) and more recently discovered peptides (i.e., relaxin-3, RLN-3; nesfatin-1, NEFA; phoenixin, PNX; spexin, SPX). For the first time, we present an up-to-date review of all published data regarding interactions between the aforementioned neuropeptide systems. The reviewed literature suggest new pathophysiological mechanisms leading to fertility disturbances that are induced by stress.
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Affiliation(s)
- Miłosz Gołyszny
- Department of Pharmacology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 Street, 40-752 Katowice, Poland.
| | - Ewa Obuchowicz
- Department of Pharmacology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 Street, 40-752 Katowice, Poland.
| | - Michał Zieliński
- Department of Pharmacology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 Street, 40-752 Katowice, Poland.
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Voglsanger LM, Read J, Ch'ng SS, Zhang C, Eraslan IM, Gray L, Rivera LR, Hamilton LD, Williams R, Gundlach AL, Smith CM. Differential Level of RXFP3 Expression in Dopaminergic Neurons Within the Arcuate Nucleus, Dorsomedial Hypothalamus and Ventral Tegmental Area of RXFP3-Cre/tdTomato Mice. Front Neurosci 2021; 14:594818. [PMID: 33584175 PMCID: PMC7873962 DOI: 10.3389/fnins.2020.594818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/07/2020] [Indexed: 11/13/2022] Open
Abstract
RXFP3 (relaxin-family peptide 3 receptor) is the cognate G-protein-coupled receptor for the neuropeptide, relaxin-3. RXFP3 is expressed widely throughout the brain, including the hypothalamus, where it has been shown to modulate feeding behavior and neuroendocrine activity in rodents. In order to better characterize its potential mechanisms of action, this study determined whether RXFP3 is expressed by dopaminergic neurons within the arcuate nucleus (ARC) and dorsomedial hypothalamus (DMH), in addition to the ventral tegmental area (VTA). Neurons that express RXFP3 were visualized in coronal brain sections from RXFP3-Cre/tdTomato mice, which express the tdTomato fluorophore within RXFP3-positive cells, and dopaminergic neurons in these areas were visualized by simultaneous immunohistochemical detection of tyrosine hydroxylase-immunoreactivity (TH-IR). Approximately 20% of ARC neurons containing TH-IR coexpressed tdTomato fluorescence, suggesting that RXFP3 can influence the dopamine pathway from the ARC to the pituitary gland that controls prolactin release. The ability of prolactin to reduce leptin sensitivity and increase food consumption therefore represents a potential mechanism by which RXFP3 activation influences feeding. A similar proportion of DMH neurons containing TH-IR expressed RXFP3-related tdTomato fluorescence, consistent with a possible RXFP3-mediated regulation of stress and neuroendocrine circuits. In contrast, RXFP3 was barely detected within the VTA. TdTomato signal was absent from the ARC and DMH in sections from Rosa26-tdTomato mice, suggesting that the cells identified in RXFP3-Cre/tdTomato mice expressed authentic RXFP3-related tdTomato fluorescence. Together, these findings identify potential hypothalamic mechanisms through which RXFP3 influences neuroendocrine control of metabolism, and further highlight the therapeutic potential of targeting RXFP3 in feeding-related disorders.
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Affiliation(s)
- Lara M Voglsanger
- Faculty of Health, School of Medicine, Institute for Innovation in Mental and Physical Health and Clinical Translation, Deakin University, Waurn Ponds, VIC, Australia
| | - Justin Read
- Faculty of Health, School of Medicine, Institute for Innovation in Mental and Physical Health and Clinical Translation, Deakin University, Waurn Ponds, VIC, Australia
| | - Sarah S Ch'ng
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Cary Zhang
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Izel M Eraslan
- Faculty of Health, School of Medicine, Institute for Innovation in Mental and Physical Health and Clinical Translation, Deakin University, Waurn Ponds, VIC, Australia
| | - Laura Gray
- Faculty of Health, School of Medicine, Institute for Innovation in Mental and Physical Health and Clinical Translation, Deakin University, Waurn Ponds, VIC, Australia
| | - Leni R Rivera
- Faculty of Health, School of Medicine, Institute for Innovation in Mental and Physical Health and Clinical Translation, Deakin University, Waurn Ponds, VIC, Australia
| | - Lee D Hamilton
- Faculty of Health, School of Exercise and Nutritional Science, Deakin University, Waurn Ponds, VIC, Australia
| | - Richard Williams
- Faculty of Health, School of Medicine, Institute for Innovation in Mental and Physical Health and Clinical Translation, Deakin University, Waurn Ponds, VIC, Australia
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Craig M Smith
- Faculty of Health, School of Medicine, Institute for Innovation in Mental and Physical Health and Clinical Translation, Deakin University, Waurn Ponds, VIC, Australia
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Kania A, Szlaga A, Sambak P, Gugula A, Blasiak E, Micioni Di Bonaventura MV, Hossain MA, Cifani C, Hess G, Gundlach AL, Blasiak A. RLN3/RXFP3 Signaling in the PVN Inhibits Magnocellular Neurons via M-like Current Activation and Contributes to Binge Eating Behavior. J Neurosci 2020; 40:5362-5375. [PMID: 32532885 PMCID: PMC7343322 DOI: 10.1523/jneurosci.2895-19.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/17/2020] [Accepted: 05/21/2020] [Indexed: 12/20/2022] Open
Abstract
Binge-eating disorder is the most common eating disorder. Various neuropeptides play important roles in the regulation of feeding behavior, including relaxin-3 (RLN3), which stimulates food intake in rats through the activation of the relaxin-family peptide-3 receptor (RXFP3). Here we demonstrate that a likely mechanism underlying the orexigenic action of RLN3 is RXFP3-mediated inhibition of oxytocin- and arginine-vasopressin-synthesizing paraventricular nucleus (PVN) magnocellular neurosecretory cells. Moreover, we reveal that, in male and female rats, this action depends on M-like potassium conductance. Notably, higher intra- and peri-PVN RLN3 fiber densities were observed in females, which may constitute an anatomic substrate for observed sex differences in binge-eating disorder. Finally, in a model of binge-eating in female rats, RXFP3 blockade within the PVN prevented binge-eating behavior. These data demonstrate a direct RLN3/RXFP3 action in the PVN of male and female rats, identify the associated ionic mechanisms, and reveal that hypothalamic RLN3/RXFP3 signaling regulates binge-eating behavior.SIGNIFICANCE STATEMENT Binge-eating disorder is the most common eating disorder worldwide, affecting women twice as frequently as men. Various neuropeptides play important roles in the regulation of feeding behavior, including relaxin-3, which acts via the relaxin-family peptide-3 receptor (RXFP3). Using a model of binge-eating, we demonstrated that relaxin-3/RXFP3 signaling in the hypothalamic paraventricular nucleus (PVN) is necessary for the expression of binge-eating behavior in female rats. Moreover, we elucidated the neuronal mechanism of RLN3/RXFP3 signaling in PVN in male and female rats and characterized sex differences in the RLN3 innervation of the PVN. These findings increase our understanding of the brain circuits and neurotransmitters involved in binge-eating disorder pathology and identify RXFP3 as a therapeutic target for binge-like eating disorders.
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Affiliation(s)
- Alan Kania
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, 30-387, Poland
- School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, 62032, Italy
| | - Agata Szlaga
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, 30-387, Poland
| | - Patryk Sambak
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, 30-387, Poland
| | - Anna Gugula
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, 30-387, Poland
| | - Ewa Blasiak
- Department of Physical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, 30-387, Poland
| | | | - Mohammad Akhter Hossain
- Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne, 3010 Victoria, Australia
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, 62032, Italy
| | - Grzegorz Hess
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, 30-387, Poland
| | - Andrew L Gundlach
- Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne, 3010 Victoria, Australia
| | - Anna Blasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, 30-387, Poland
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