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Flisher MF, Shin D, Huising MO. Urocortin3: Local inducer of somatostatin release and bellwether of beta cell maturity. Peptides 2022; 151:170748. [PMID: 35065098 PMCID: PMC10881066 DOI: 10.1016/j.peptides.2022.170748] [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: 11/26/2021] [Revised: 01/03/2022] [Accepted: 01/17/2022] [Indexed: 11/25/2022]
Abstract
Urocortin 3 (UCN3) is a peptide hormone expressed in pancreatic islets of Langerhans of both human alpha and human beta cells and solely in murine beta cells. UCN3 signaling acts locally within the islet to activate its cognate receptor, corticotropin releasing hormone receptor 2 (CRHR2), which is expressed by delta cells, to potentiate somatostatin (SST) negative feedback to reduce islet cell hormone output. The functional importance of UCN3 signaling in the islet is to modulate the amount of SST tone allowing for finely tuned regulation of insulin and glucagon secretion. UCN3 signaling is a hallmark of functional beta cell maturation, increasing the beta cell glucose threshold for insulin secretion. In doing so, UCN3 plays a relevant functional role in accurately maintaining blood glucose homeostasis. Additionally, UCN3 acts as an indicator of beta cell maturation and health, as UCN3 is not expressed in immature beta cells and is downregulated in dedifferentiated and dysfunctional beta cell states. Here, we review the mechanistic underpinnings of UCN3 signaling, its net effect on islet cell hormone output, as well as its value as a marker for beta cell maturation and functional status.
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Affiliation(s)
- Marcus F Flisher
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA, United States
| | - Donghan Shin
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA, United States
| | - Mark O Huising
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA, United States; Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, CA, United States.
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2
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Qi J, Zhang X, Li Y, Xu S, Wang M, Chen H, Tang N, Wang S, Wang B, Chen D, Zhou B, Li Z. The suppression effects of feeding and mechanisms in CRF system of animals. Gene 2020; 733:144363. [PMID: 31935510 DOI: 10.1016/j.gene.2020.144363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 01/27/2023]
Abstract
CRF system is comprised of 4 homologous lineages, 2 main receptors (CRF-R1 and CRF-R2), and a binding protein CRF-BP. The homologous lineages are corticotropin-releasing factor (CRF), urotensin I (UI)/sauvagine (SVG)/urocortin 1 (UCN1), urocortin 2 (UCN2), and urocortin 3 (UCN3), and UI, SVG, UCN1 are orthologous genes. CRF system genes are widely distributed in the brain and gastrointestinal tract, which may relate to feeding regulation. According the research progress about CRF system on mammals and non-mammals, this paper summarized the discovery, structure, tissue distribution, appetite regulation and mechanism of CRF system in animals, which can provide the reference for further research and production of feeding regulation and growth in mammals and fish species.
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Affiliation(s)
- Jinwen Qi
- Fisheries Institute, Sichuan Academy of Agricultural Sciences, 156# Gaozhuang Bridge Community, Yibin, Sichuan, China
| | - Xin Zhang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China; The Key Laboratory of Mariculture, Ministry of Education, Fisheries College, Ocean University of China, 5# Yushan Road, Qingdao, Shandong, China
| | - Ya Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Shaoqi Xu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Mei Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Hu Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Ni Tang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Shuyao Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Bin Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Defang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Bo Zhou
- Fisheries Institute, Sichuan Academy of Agricultural Sciences, 156# Gaozhuang Bridge Community, Yibin, Sichuan, China.
| | - Zhiqiong Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China.
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Li H, Page AJ. Activation of CRF2 receptor increases gastric vagal afferent mechanosensitivity. J Neurophysiol 2019; 122:2636-2642. [DOI: 10.1152/jn.00619.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Gastric vagal afferent (GVA) sensing of food-related mechanical stimuli is a crucial mechanism in the control of feeding behavior and gastric function. Stress is an important factor contributing to eating disorders and gastric diseases. Chronic stress has been shown to increase the mechanosensitivity of GVAs in mice and to reduce food intake and body weight. Whether the mechanosensitivity of GVAs is modulated by stress hormones is not known. This study aimed to determine the effect of stress hormones on GVA mechanosensitivity. The expression of stress hormone receptors in GVA cell bodies was determined in 8-wk-old male C57BL/6 mice using quantitative RT-PCR combined with laser capture microdissection. The mechanosensitivity of GVAs was determined in the absence and presence of stress hormones using an in vitro single-fiber recording preparation. NR3C1 and CRHR2 (mRNA isoforms of glucocorticoid receptor and CRF2 receptor, respectively) were expressed in GVA neurons. The glucocorticoid receptor agonist corticosterone had no effect on the mechanosensitivity of either tension or mucosal GVAs. Activation of CRF2 receptor by its specific analog, urocortin 3, significantly increased the mechanosensitivity of both tension and mucosal GVAs, an effect prevented by the CRF2 receptor antagonist astressin 2B. In conclusion, activation of CRF2 receptor increases the mechanosensitivity of GVAs. This may contribute to the stress- and CRF2 receptor-associated changes in feeding behavior and gastric function, possibly contributing to the hypersensitivity of GVAs in chronic stress conditions. NEW & NOTEWORTHY Gastric vagal afferents (GVAs) relay food-related signals to the central nervous system, where they are processed, eventually leading to modulation of food intake and gastric function. GVA signaling can be modulated by an array of hormones. Stress has been shown to induce GVA hypersensitivity. This study demonstrates that GVA neurons express subtypes of stress hormone receptors, specifically CRF2. Furthermore, activation of CRF2 receptor increases GVA mechanosensitivity, which could have implications for food intake and gastric function.
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Affiliation(s)
- Hui Li
- Vagal Afferent Research Group, Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Diabetes, Nutrition & Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Amanda J. Page
- Vagal Afferent Research Group, Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Diabetes, Nutrition & Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
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Zhang X, Liu Y, Qi J, Tian Z, Tang N, Chen D, Li Z. Progress in understanding the roles of Urocortin3 (UCN3) in the control of appetite from studies using animal models. Peptides 2019; 121:170124. [PMID: 31415798 DOI: 10.1016/j.peptides.2019.170124] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 07/19/2019] [Accepted: 08/05/2019] [Indexed: 11/19/2022]
Abstract
Urocortin3 (UCN3), the newest member of corticotrophin releasing hormone (CRH) family polypeptides, is an anorexic factor discovered in 2001, which has a strong inhibitory effect on animal appetite regulation. UCN3 is widely distributed in various tissues of animals and has many biological functions. Based on the research progress of UCN3 on mammals and non-mammals, this paper summarized the discovery, tissue distribution, appetite regulation and mechanism of UCN3 in animals, in order to provide a reference for feeding regulation and growth in mammals and fish in further research and production.
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Affiliation(s)
- Xin Zhang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China; The Key Laboratory of Mariculture, Ministry of Education, Fisheries College, Ocean University of China, 5# Yushan Road, Qingdao, Shandong, China
| | - Yanling Liu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Jinwen Qi
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Zhengzhi Tian
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Ni Tang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Defang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Zhiqiong Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China.
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Nozu T, Miyagishi S, Nozu R, Takakusaki K, Okumura T. Altered colonic sensory and barrier functions by CRF: roles of TLR4 and IL-1. J Endocrinol 2018; 239:241-252. [PMID: 30139928 DOI: 10.1530/joe-18-0441] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 08/22/2018] [Indexed: 12/12/2022]
Abstract
Visceral allodynia and increased colonic permeability are considered to be crucial pathophysiology of irritable bowel syndrome (IBS). Corticotropin-releasing factor (CRF) and immune-mediated mechanisms have been proposed to contribute to these changes in IBS, but the precise roles have not been determined. We explored these issues in rats in vivo. The threshold of visceromotor response, i.e., abdominal muscle contractions induced by colonic balloon distention was electrophysiologically measured. Colonic permeability was estimated by quantifying the absorbed Evans blue in colonic tissue. Intraperitoneal injection of CRF increased the permeability, which was blocked by astressin, a non-selective CRF receptor antagonist, but astressin2-B, a selective CRF receptor subtype 2 (CRF2) antagonist did not modify it. Urocortin 2, a selective CRF2 agonist inhibited the increased permeability by CRF. Eritoran, a toll-like receptor 4 (TLR4) antagonist or anakinra, an interleukin-1 receptor antagonist blocked the visceral allodynia and the increased gut permeability induced by CRF. Subcutaneous injection of lipopolysaccharide (immune stress) or repeated water avoidance stress (WAS, psychological stress), 1 h daily for 3 days induced visceral allodynia and increased gut permeability (animal IBS models), which were also blocked by astressin, eritoran or anakinra. In conclusion, stress-induced visceral allodynia and increased colonic permeability were mediated via peripheral CRF receptors. CRF induced these visceral changes via TLR4 and cytokine system, which were CRF1 dependent, and activation of CRF2 inhibited these CRF1-triggered responses. CRF may modulate immune system to alter visceral changes, which are considered to be pivotal pathophysiology of IBS.
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Affiliation(s)
- Tsukasa Nozu
- Department of Regional Medicine and Education, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Saori Miyagishi
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Rintaro Nozu
- Department of Regional Medicine and Education, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Kaoru Takakusaki
- Research Center for Brain Function and Medical Engineering, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Toshikatsu Okumura
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
- Department of General Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
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Bülbül M, Sinen O, İzgüt‐Uysal VN, Akkoyunlu G, Öztürk S, Uysal F. Peripheral apelin mediates stress‐induced alterations in gastrointestinal motor functions depending on the nutritional status. Clin Exp Pharmacol Physiol 2018; 46:29-39. [DOI: 10.1111/1440-1681.13032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/03/2018] [Accepted: 09/11/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Mehmet Bülbül
- Department of Physiology Faculty of Medicine Akdeniz University AntalyaTurkey
| | - Osman Sinen
- Department of Physiology Faculty of Medicine Akdeniz University AntalyaTurkey
| | | | - Gökhan Akkoyunlu
- Department of Histology and Embryology Faculty of Medicine Akdeniz University Antalya Turkey
| | - Saffet Öztürk
- Department of Histology and Embryology Faculty of Medicine Akdeniz University Antalya Turkey
| | - Fatma Uysal
- Department of Histology and Embryology Faculty of Medicine Akdeniz University Antalya Turkey
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Stengel A, Taché Y. Gut-Brain Neuroendocrine Signaling Under Conditions of Stress-Focus on Food Intake-Regulatory Mediators. Front Endocrinol (Lausanne) 2018; 9:498. [PMID: 30210455 PMCID: PMC6122076 DOI: 10.3389/fendo.2018.00498] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/08/2018] [Indexed: 12/12/2022] Open
Abstract
The gut-brain axis represents a bidirectional communication route between the gut and the central nervous system comprised of neuronal as well as humoral signaling. This system plays an important role in the regulation of gastrointestinal as well as homeostatic functions such as hunger and satiety. Recent years also witnessed an increased knowledge on the modulation of this axis under conditions of exogenous or endogenous stressors. The present review will discuss the alterations of neuroendocrine gut-brain signaling under conditions of stress and the respective implications for the regulation of food intake.
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Affiliation(s)
- Andreas Stengel
- Department of Psychosomatic Medicine and Psychotherapy, University Hospital Tübingen, Tübingen, Germany
- Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Yvette Taché
- CURE/Digestive Diseases Research Center, Vatche and Tamar Manoukian Digestive Diseases Division, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- VA Greater Los Angeles Health Care System, Los Angeles, CA, United States
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Stengel A, Taché YF. Activation of Brain Somatostatin Signaling Suppresses CRF Receptor-Mediated Stress Response. Front Neurosci 2017; 11:231. [PMID: 28487631 PMCID: PMC5403923 DOI: 10.3389/fnins.2017.00231] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/06/2017] [Indexed: 12/30/2022] Open
Abstract
Corticotropin-releasing factor (CRF) is the hallmark brain peptide triggering the response to stress and mediates—in addition to the stimulation of the hypothalamus-pituitary-adrenal (HPA) axis—other hormonal, behavioral, autonomic and visceral components. Earlier reports indicate that somatostatin-28 injected intracerebroventricularly counteracts the acute stress-induced ACTH and catecholamine release. Mounting evidence now supports that activation of brain somatostatin signaling exerts a broader anti-stress effect by blunting the endocrine, autonomic, behavioral (with a focus on food intake) and visceral gastrointestinal motor responses through the involvement of distinct somatostatin receptor subtypes.
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Affiliation(s)
- Andreas Stengel
- Division of Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Charité-Universitätsmedizin BerlinBerlin, Germany
| | - Yvette F Taché
- Vatche and Tamar Manoukian Digestive Diseases Division, CURE Digestive Diseases Research Center, G Oppenheimer Center for Neurobiology of Stress and Resilience, Department of Medicine, University of California, Los AngelesLos Angeles, CA, USA.,VA Greater Los Angeles Health Care SystemLos Angeles, CA, USA
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Nozu T, Miyagishi S, Nozu R, Takakusaki K, Okumura T. Lipopolysaccharide induces visceral hypersensitivity: role of interleukin-1, interleukin-6, and peripheral corticotropin-releasing factor in rats. J Gastroenterol 2017; 52:72-80. [PMID: 27075754 DOI: 10.1007/s00535-016-1208-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/24/2016] [Indexed: 02/04/2023]
Abstract
BACKGROUND Lipopolysaccharide (LPS) induces visceral hypersensitivity, and corticotropin-releasing factor (CRF) also modulates visceral sensation. Besides, LPS increases CRF immunoreactivity in rat colon, which raises the possibility of the existence of a link between LPS and the CRF system in modulating visceral sensation. The present study tried to clarify this possibility. METHODS Visceral sensation was assessed by abdominal muscle contractions induced by colonic balloon distention, i.e., visceromotor response, electrophysiologically in conscious rats. The threshold of visceromotor response was measured before and after administration of drugs. RESULTS LPS at a dose of 1 mg/kg subcutaneously (sc) decreased the threshold at 3 h after the administration. Intraperitoneal (ip) administration of anakinra (20 mg/kg), an interleukin-1 (IL-1) receptor antagonist, or interleukin-6 (IL-6) antibody (16.6 µg/kg) blocked this effect. Additionally, IL-1β (10 µg/kg, sc) or IL-6 (10 µg/kg, sc) induced visceral allodynia. Astressin (200 µg/kg, ip), a non-selective CRF receptor antagonist, abolished the effect of LPS, but astressin2-B (200 µg/kg, ip), a CRF receptor type 2 (CRF2) antagonist, did not alter it. Peripheral CRF receptor type 1 (CRF1) stimulation by cortagine (60 µg/kg, ip) exaggerated the effect of LPS, but activation of CRF2 by urocortin 2 (60 µg/kg, ip) abolished it. CONCLUSIONS LPS induced visceral allodynia possibly through stimulating IL-1 and IL-6 release. In addition, this effect was mediated through peripheral CRF signaling. Since the LPS-cytokine system is thought to contribute to altered visceral sensation in the patients with irritable bowel syndrome, these results may further suggest that CRF plays a crucial role in the pathophysiology of this disease.
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Affiliation(s)
- Tsukasa Nozu
- Department of Regional Medicine and Education, Asahikawa Medical University, Midorigaoka Higashi 2-1-1-1, Asahikawa, 078-8510, Japan.
| | - Saori Miyagishi
- Department of General Medicine, Asahikawa Medical University, Midorigaoka Higashi 2-1-1-1, Asahikawa, 078-8510, Japan
| | - Rintaro Nozu
- Department of Regional Medicine and Education, Asahikawa Medical University, Midorigaoka Higashi 2-1-1-1, Asahikawa, 078-8510, Japan
| | - Kaoru Takakusaki
- Research Center for Brain Function and Medical Engineering, Asahikawa Medical University, Midorigaoka Higashi 2-1-1-1, Asahikawa, 078-8510, Japan
| | - Toshikatsu Okumura
- Department of General Medicine, Asahikawa Medical University, Midorigaoka Higashi 2-1-1-1, Asahikawa, 078-8510, Japan
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Yuan PQ, Wu SV, Pothoulakis C, Taché Y. Urocortins and CRF receptor type 2 variants in the male rat colon: gene expression and regulation by endotoxin and anti-inflammatory effect. Am J Physiol Gastrointest Liver Physiol 2016; 310:G387-98. [PMID: 26744472 PMCID: PMC4796293 DOI: 10.1152/ajpgi.00337.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/30/2015] [Indexed: 01/31/2023]
Abstract
Urocortins (Ucns) 1, 2, and 3 and corticotropin-releasing factor receptor 2 (CRF2) mRNA are prominently expressed in various layers of the upper gut. We tested whether Ucns and CRF2 variants are also expressed in the different layers of the rat colon, regulated by LPS (100 μg/kg ip) and play a modulatory role in the colonic immune response to LPS. Transcripts of Ucns and CRF2b, the most common isoform in the periphery, were detected in all laser microdissected layers, including myenteric neurons. LPS increased the mRNA level of Ucn 1, Ucn 2, and Ucn 3 and decreased that of CRF2b in both the colonic mucosa and submucosa + muscle (S+M) layers at 2, 6, and 9 h after injection with a return to basal at 24 h. In addition, CRF2a, another variant more prominent in the brain, and a novel truncated splice variant CRF2a-3 mRNA were detected in all segments of the large intestine. LPS reciprocally regulated the colonic expression of these CRF2 variants by decreasing both CRF2a and CRF2b, while increasing CRF2a-3 in the mucosa and S+M. The CRF2 antagonist astressin2-B further enhanced LPS-induced increase of mRNA level of interleukin (IL)-1β, TNF-α, and inducible nitric oxide synthase in S+M layers and IL-1β in the mucosa and evoked TNF-α expression in the mucosa. These data indicate that Ucns/CRF2 variants are widely expressed in all colonic layers and reciprocally regulated by LPS. CRF2 signaling dampens the CD14/TLR4-mediated acute inflammatory response to Gram-negative bacteria in the colon.
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Affiliation(s)
- Pu-Qing Yuan
- Center for Neurobiology of Stress, Inflammatory Bowel Disease Center, CURE: Digestive Diseases Research Center, Digestive Diseases Division, Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine and Brain Research Institute, University of California, Los Angeles, California
| | - S Vincent Wu
- Center for Neurobiology of Stress, Inflammatory Bowel Disease Center, CURE: Digestive Diseases Research Center, Digestive Diseases Division, Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine and Brain Research Institute, University of California, Los Angeles, California
| | - Charalabos Pothoulakis
- Center for Neurobiology of Stress, Inflammatory Bowel Disease Center, CURE: Digestive Diseases Research Center, Digestive Diseases Division, Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine and Brain Research Institute, University of California, Los Angeles, California
| | - Yvette Taché
- Center for Neurobiology of Stress, Inflammatory Bowel Disease Center, CURE: Digestive Diseases Research Center, Digestive Diseases Division, Veterans Affairs Greater Los Angeles Healthcare System, Department of Medicine and Brain Research Institute, University of California, Los Angeles, California
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11
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Taché Y, Million M. Role of Corticotropin-releasing Factor Signaling in Stress-related Alterations of Colonic Motility and Hyperalgesia. J Neurogastroenterol Motil 2015; 21:8-24. [PMID: 25611064 PMCID: PMC4288101 DOI: 10.5056/jnm14162] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 12/28/2014] [Indexed: 12/13/2022] Open
Abstract
The corticotropin-releasing factor (CRF) signaling systems encompass CRF and the structurally related peptide urocortin (Ucn) 1, 2, and 3 along with 2 G-protein coupled receptors, CRF1 and CRF2. CRF binds with high and moderate affinity to CRF1 and CRF2 receptors, respectively while Ucn1 is a high-affinity agonist at both receptors, and Ucn2 and Ucn3 are selective CRF2 agonists. The CRF systems are expressed in both the brain and the colon at the gene and protein levels. Experimental studies established that the activation of CRF1 pathway in the brain or the colon recaptures cardinal features of diarrhea predominant irritable bowel syndrome (IBS) (stimulation of colonic motility, activation of mast cells and serotonin, defecation/watery diarrhea, and visceral hyperalgesia). Conversely, selective CRF1 antagonists or CRF1/CRF2 antagonists, abolished or reduced exogenous CRF and stress-induced stimulation of colonic motility, defecation, diarrhea and colonic mast cell activation and visceral hyperalgesia to colorectal distention. By contrast, the CRF2 signaling in the colon dampened the CRF1 mediated stimulation of colonic motor function and visceral hyperalgesia. These data provide a conceptual framework that sustained activation of the CRF1 system at central and/or peripheral sites may be one of the underlying basis of IBS-diarrhea symptoms. While targeting these mechanisms by CRF1 antagonists provided a relevant novel therapeutic venue, so far these promising preclinical data have not translated into therapeutic use of CRF1 antagonists. Whether the existing or newly developed CRF1 antagonists will progress to therapeutic benefits for stress-sensitive diseases including IBS for a subset of patients is still a work in progress.
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Affiliation(s)
- Yvette Taché
- CURE/Digestive Diseases Research Center, and Center for the Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, University of California Los Angeles, and VA Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Mulugeta Million
- CURE/Digestive Diseases Research Center, and Center for the Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, University of California Los Angeles, and VA Greater Los Angeles Healthcare System, Los Angeles, California, USA
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12
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Nozu T, Takakusaki K, Okumura T. A balance theory of peripheral corticotropin-releasing factor receptor type 1 and type 2 signaling to induce colonic contractions and visceral hyperalgesia in rats. Endocrinology 2014; 155:4655-64. [PMID: 25279793 DOI: 10.1210/en.2014-1421] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Several recent studies suggest that peripheral corticotropin-releasing factor (CRF) receptor type 1 (CRF1) and CRF2 have a counter regulatory action on gastrointestinal functions. We hypothesized that the activity balance of each CRF subtype signaling may determine the changes in colonic motility and visceral sensation. Colonic contractions were assessed by the perfused manometry, and contractions of colonic muscle strips were measured in vitro in rats. Visceromotor response was determined by measuring contractions of abdominal muscle in response to colorectal distensions (CRDs) (60 mm Hg for 10 min twice with a 30-min rest). All drugs were administered through ip route in in vivo studies. CRF increased colonic contractions. Pretreatment with astressin, a nonselective CRF antagonist, blocked the CRF-induced response, but astressin2-B, a selective CRF2 antagonist, enhanced the response by CRF. Cortagine, a selective CRF1 agonist, increased colonic contractions. In in vitro study, CRF increased contractions of muscle strips. Urocortin 2, a selective CRF2 agonist, itself did not alter the contractions but blocked this increased response by CRF. Visceromotor response to the second CRD was significantly higher than that of the first. Astressin blocked this CRD-induced sensitization, but astressin2-B or CRF did not affect it. Meanwhile, astressin2-B together with CRF significantly enhanced the sensitization. Urocortin 2 blocked, but cortagine significantly enhanced, the sensitization. These results indicated that peripheral CRF1 signaling enhanced colonic contractility and induced visceral sensitization, and these responses were modulated by peripheral CRF2 signaling. The activity balance of each subtype signaling may determine the colonic functions in response to stress.
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Affiliation(s)
- Tsukasa Nozu
- Departments of Regional Medicine and Education (T.N.) and General Medicine (T.O.) and Research Center for Brain Function and Medical Engineering (K.T.), Asahikawa Medical University, Asahikawa 078-8510, Japan
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Urocortin 2 blocks the suppression of gastric antral contractions induced by lipopolysaccharide in freely moving conscious rats. ACTA ACUST UNITED AC 2014; 190-191:12-7. [PMID: 24793550 DOI: 10.1016/j.regpep.2014.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 04/02/2014] [Accepted: 04/22/2014] [Indexed: 12/15/2022]
Abstract
Lipopolysaccharide (LPS) inhibits gastric antral contractions in conscious rats. Since LPS regulates corticotropin-releasing factor type 2 receptor (CRF2) expression in the rat stomach, and activation of peripheral CRF2 alters gastric motility, we tried to determine the role of peripheral CRF2 in the LPS-induced suppression of gastric antral contractions. Intraluminal gastric pressure waves were measured in freely moving conscious non-fasted rats using the perfused manometric method. We assessed the area under the manometric trace as the motor index (MI), and compared this result with those obtained 1h before and after intraperitoneal injection of drugs. LPS (0.2 mg/kg) significantly decreased MI. Indomethacin (10 mg/kg) itself did not alter MI but blocked this inhibitory action by LPS. Astressin 2-B (200 μg/kg), a selective CRF2 antagonist, modified neither the basal MI nor the action by LPS. Meanwhile, urocortin 2 (30 μg/kg), a selective CRF2 agonist, reversed the suppression by LPS without affecting the basal MI. This action by urocortin 2 was blocked by pretreatment with astressin 2-B. In conclusion, LPS inhibited gastric antral contractions possibly through a prostaglandin-dependent pathway. Peripheral CRF2 stimulation reversed this response by LPS.
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Abstract
Although the idea that gastric problems are in some way related to mental activity dates back to the beginning of the last century, until now it has received scant attention by physiologists, general practitioners and gastroenterologists. The major breakthrough in understanding the interactions between the central nervous system and the gut was the discovery of the enteric nervous system (ENS) in the 19th century. ENS (also called 'little brain') plays a crucial role in the regulation of the physiological gut functions. Furthermore, the identification of corticotropin-releasing factor (CRF) and the development of specific CRF receptor antagonists have permitted to characterize the neurochemical basis of the stress response. The neurobiological response to stress in mammals involves three key mechanisms: (1) stress is perceived and processed by higher brain centers; (2) the brain mounts a neuroendocrine response by way of the hypothalamic-pituitary-adrenal axis (HPA) and the autonomic nervous system (ANS), and (3) the brain triggers feedback mechanisms by HPA and ANS stimulation to restore homeostasis. Various stressors such as anger, fear, painful stimuli, as well as life or social learning experiences affect both the individual's physiologic and gastric function, revealing a two-way interaction between brain and stomach. There is overwhelming experimental and clinical evidence that stress influences gastric function, thereby outlining the pathogenesis of gastric diseases such as functional dyspepsia, gastroesophageal reflux disease and peptic ulcer disease. A better understanding of the role of pathological stressors in the modulation of disease activity may have important pathogenetic and therapeutic implications.
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Affiliation(s)
- Gerardo Nardone
- Gastroenterology Unit, Department of Clinical Medicine and Surgery, University Federico II of Naples, Naples, Italy
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15
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Stengel A, Taché Y. CRF and urocortin peptides as modulators of energy balance and feeding behavior during stress. Front Neurosci 2014; 8:52. [PMID: 24672423 PMCID: PMC3957495 DOI: 10.3389/fnins.2014.00052] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 02/26/2014] [Indexed: 12/19/2022] Open
Abstract
Early on, corticotropin-releasing factor (CRF), a hallmark brain peptide mediating many components of the stress response, was shown to affect food intake inducing a robust anorexigenic response when injected into the rodent brain. Subsequently, other members of the CRF signaling family have been identified, namely urocortin (Ucn) 1, Ucn 2, and Ucn 3 which were also shown to decrease food intake upon central or peripheral injection. However, the kinetics of feeding suppression was different with an early decrease following intracerebroventricular injection of CRF and a delayed action of Ucns contrasting with the early onset after systemic injection. CRF and Ucns bind to two distinct G-protein coupled membrane receptors, the CRF1 and CRF2. New pharmacological tools such as highly selective peptide CRF1 or CRF2 agonists or antagonists along with genetic knock-in or knock-out models have allowed delineating the primary role of CRF2 involved in the anorexic response to exogenous administration of CRF and Ucns. Several stressors trigger behavioral changes including suppression of feeding behavior which are mediated by brain CRF receptor activation. The present review will highlight the state-of-knowledge on the effects and mechanisms of action of CRF/Ucns-CRF1/2 signaling under basal conditions and the role in the alterations of food intake in response to stress.
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Affiliation(s)
- Andreas Stengel
- Division of General Internal and Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Charité-Universitätsmedizin BerlinBerlin, Germany
| | - Yvette Taché
- CURE: Digestive Diseases Research Center, Center for Neurobiology of Stress and Women's Health, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care SystemLos Angeles, CA, USA
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Watanabe K, Nemoto T, Akira S, Takeshita T, Shibasaki T. Estrogens downregulate urocortin 2 expression in rat uterus. J Endocrinol 2013; 219:269-78. [PMID: 24109089 DOI: 10.1530/joe-13-0228] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Urocortin 2 (Ucn2) is a member of the corticotropin-releasing factor peptide family and is expressed by various tissues, including reproductive tissues such as the uterus, ovary, and placenta. However, the regulatory mechanisms of Ucn2 expression and the physiological significance of Ucn2 in these tissues remain unclear. We previously showed that passive immunization of immature female rats by i.p. injection of anti-Ucn2 IgG induces earlier onset of puberty. Therefore, this study was designed to clarify the site and regulatory mechanisms of Ucn2 expression in the uterus. Expression levels of Ucn2 mRNA in the uterus were higher in immature (2- and 4-week-old) and aged (17-month-old) rats than in mature (9-week-old) rats in the proestrus phase. In 9-week-old rats, mRNA expression levels and contents in the uterus were lower in the proestrus phase than in the diestrus phase, while plasma Ucn2 concentrations did not differ between the two phases. Ucn2-like immunoreactivitiy was detected in the endometrial gland epithelial cells of the uterus. S.c. injection of estradiol benzoate or an estrogen receptor α (ERα) agonist significantly reduced mRNA expression levels and contents of Ucn2 in the uterus when compared with vehicle-injected ovariectomized rats. By contrast, estradiol benzoate increased Ucn2 mRNA expression levels in the lung. Thus, estrogens downregulate Ucn2 expression in the uterus in a tissue-specific manner, and Ucn2 may play a role in the regulatory mechanisms of maturation of the uterus through ERα and estrous cycle.
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Affiliation(s)
- Kenichiro Watanabe
- Departments of Obstetrics and Gynecology Physiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan
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Slominski AT, Zmijewski MA, Zbytek B, Tobin DJ, Theoharides TC, Rivier J. Key role of CRF in the skin stress response system. Endocr Rev 2013; 34:827-84. [PMID: 23939821 PMCID: PMC3857130 DOI: 10.1210/er.2012-1092] [Citation(s) in RCA: 277] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 08/02/2013] [Indexed: 02/08/2023]
Abstract
The discovery of corticotropin-releasing factor (CRF) or CRH defining the upper regulatory arm of the hypothalamic-pituitary-adrenal (HPA) axis, along with the identification of the corresponding receptors (CRFRs 1 and 2), represents a milestone in our understanding of central mechanisms regulating body and local homeostasis. We focused on the CRF-led signaling systems in the skin and offer a model for regulation of peripheral homeostasis based on the interaction of CRF and the structurally related urocortins with corresponding receptors and the resulting direct or indirect phenotypic effects that include regulation of epidermal barrier function, skin immune, pigmentary, adnexal, and dermal functions necessary to maintain local and systemic homeostasis. The regulatory modes of action include the classical CRF-led cutaneous equivalent of the central HPA axis, the expression and function of CRF and related peptides, and the stimulation of pro-opiomelanocortin peptides or cytokines. The key regulatory role is assigned to the CRFR-1α receptor, with other isoforms having modulatory effects. CRF can be released from sensory nerves and immune cells in response to emotional and environmental stressors. The expression sequence of peptides includes urocortin/CRF→pro-opiomelanocortin→ACTH, MSH, and β-endorphin. Expression of these peptides and of CRFR-1α is environmentally regulated, and their dysfunction can lead to skin and systemic diseases. Environmentally stressed skin can activate both the central and local HPA axis through either sensory nerves or humoral factors to turn on homeostatic responses counteracting cutaneous and systemic environmental damage. CRF and CRFR-1 may constitute novel targets through the use of specific agonists or antagonists, especially for therapy of skin diseases that worsen with stress, such as atopic dermatitis and psoriasis.
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Affiliation(s)
- Andrzej T Slominski
- MD, PhD, Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center; 930 Madison Avenue, Suite 500, Memphis, Tennessee 38163.
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Wang L, Stengel A, Goebel-Stengel M, Shaikh A, Yuan PQ, Taché Y. Intravenous injection of urocortin 1 induces a CRF2 mediated increase in circulating ghrelin and glucose levels through distinct mechanisms in rats. Peptides 2013; 39. [PMID: 23183626 PMCID: PMC3599411 DOI: 10.1016/j.peptides.2012.11.009] [Citation(s) in RCA: 11] [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] [Indexed: 12/19/2022]
Abstract
Urocortins (Ucns) injected peripherally decrease food intake and gastric emptying through peripheral CRF(2) receptors in rodents. However, whether Ucns influence circulating levels of the orexigenic and prokinetic hormone, ghrelin has been little investigated. We examined plasma levels of ghrelin and blood glucose after intravenous (iv) injection of Ucn 1, the CRF receptor subtype involved and underlying mechanisms in ad libitum fed rats equipped with a chronic iv cannula. Ucn 1 (10 μg/kg, iv) induced a rapid onset and long lasting increase in ghrelin levels reaching 68% and 219% at 0.5 and 3h post injection respectively and a 5-h hyperglycemic response. The selective CRF(2) agonist, Ucn 2 (3 μg/kg, iv) increased fasting acyl (3h: 49%) and des-acyl ghrelin levels (3h: 30%) compared to vehicle while the preferential CRF(1) agonist, CRF (3 μg/kg, iv) had no effect. Ucn 1's stimulatory actions were blocked by the selective CRF(2) antagonist, astressin(2)-B (100 μg/kg, iv). Hexamethonium (10 mg/kg, sc) prevented Ucn 1-induced rise in total ghrelin levels while not altering the hyperglycemic response. These data indicate that systemic injection of Ucns induces a CRF(2)-mediated increase in circulating ghrelin levels likely via indirect actions on gastric ghrelin cells that involves a nicotinic pathway independently from the hyperglycemic response.
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Affiliation(s)
- Lixin Wang
- CURE/Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at University of California Los Angeles, Los Angeles, CA 90073, USA.
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