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Bozadjieva-Kramer N, Ross RA, Johnson DQ, Fenselau H, Haggerty DL, Atwood B, Lowell B, Flak JN. The Role of Mediobasal Hypothalamic PACAP in the Control of Body Weight and Metabolism. Endocrinology 2021; 162:6103920. [PMID: 33460433 PMCID: PMC7875177 DOI: 10.1210/endocr/bqab012] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Indexed: 12/26/2022]
Abstract
Body energy homeostasis results from balancing energy intake and energy expenditure. Central nervous system administration of pituitary adenylate cyclase activating polypeptide (PACAP) dramatically alters metabolic function, but the physiologic mechanism of this neuropeptide remains poorly defined. PACAP is expressed in the mediobasal hypothalamus (MBH), a brain area essential for energy balance. Ventromedial hypothalamic nucleus (VMN) neurons contain, by far, the largest and most dense population of PACAP in the medial hypothalamus. This region is involved in coordinating the sympathetic nervous system in response to metabolic cues in order to re-establish energy homeostasis. Additionally, the metabolic cue of leptin signaling in the VMN regulates PACAP expression. We hypothesized that PACAP may play a role in the various effector systems of energy homeostasis, and tested its role by using VMN-directed, but MBH encompassing, adeno-associated virus (AAVCre) injections to ablate Adcyap1 (gene coding for PACAP) in mice (Adcyap1MBHKO mice). Adcyap1MBHKO mice rapidly gained body weight and adiposity, becoming hyperinsulinemic and hyperglycemic. Adcyap1MBHKO mice exhibited decreased oxygen consumption (VO2), without changes in activity. These effects appear to be due at least in part to brown adipose tissue (BAT) dysfunction, and we show that PACAP-expressing cells in the MBH can stimulate BAT thermogenesis. While we observed disruption of glucose clearance during hyperinsulinemic/euglycemic clamp studies in obese Adcyap1MBHKO mice, these parameters were normal prior to the onset of obesity. Thus, MBH PACAP plays important roles in the regulation of metabolic rate and energy balance through multiple effector systems on multiple time scales, which highlight the diverse set of functions for PACAP in overall energy homeostasis.
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Affiliation(s)
| | - Rachel A Ross
- Albert Einstein College of Medicine, Bronx, NY, USA
- Beth Israel Deaconess Medical Center, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - David Q Johnson
- Indiana Biosciences Research Institute, Diabetes Research Center, Indianapolis, IN, USA
| | - Henning Fenselau
- Beth Israel Deaconess Medical Center, Boston, MA, USA
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Cologne, Germany
- Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - David L Haggerty
- Indiana University School of Medicine, Pharmacology and Toxicology, Indianapolis, IN, USA
| | - Brady Atwood
- Indiana University School of Medicine, Pharmacology and Toxicology, Indianapolis, IN, USA
| | - Bradford Lowell
- Beth Israel Deaconess Medical Center, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Jonathan N Flak
- Indiana Biosciences Research Institute, Diabetes Research Center, Indianapolis, IN, USA
- Indiana University School of Medicine, Pharmacology and Toxicology, Indianapolis, IN, USA
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, Ann Arbor, MI, USA
- Correspondence: Jonathan N. Flak, PhD, Indiana Biosciences Research Institute, 1345 W. 16th Street, Indianapolis, IN 46022, USA.
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PACAP-38 in Acute ST-Segment Elevation Myocardial Infarction in Humans and Pigs: A Translational Study. Int J Mol Sci 2021; 22:ijms22062883. [PMID: 33809145 PMCID: PMC8002092 DOI: 10.3390/ijms22062883] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/03/2021] [Accepted: 03/06/2021] [Indexed: 12/14/2022] Open
Abstract
Acute myocardial infarction (MI) is one of the most common causes of death worldwide. Pituitary adenylate cyclase activating polypeptide (PACAP) is a cardioprotective neuropeptide expressing its receptors in the cardiovascular system. The aim of our study was to examine tissue PACAP-38 in a translational porcine MI model and plasma PACAP-38 levels in patients with ST-segment elevation myocardial infarction (STEMI). Significantly lower PACAP-38 levels were detected in the non-ischemic region of the left ventricle (LV) in MI heart compared to the ischemic region of MI-LV and also to the Sham-operated LV in porcine MI model. In STEMI patients, plasma PACAP-38 level was significantly higher before percutaneous coronary intervention (PCI) compared to controls, and decreased after PCI. Significant negative correlation was found between plasma PACAP-38 and troponin levels. Furthermore, a significant effect was revealed between plasma PACAP-38, hypertension and HbA1c levels. This was the first study showing significant changes in cardiac tissue PACAP levels in a porcine MI model and plasma PACAP levels in STEMI patients. These results suggest that PACAP, due to its cardioprotective effects, may play a regulatory role in MI and could be a potential biomarker or drug target in MI.
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Winters SJ, Moore JP. PACAP: A regulator of mammalian reproductive function. Mol Cell Endocrinol 2020; 518:110912. [PMID: 32561449 PMCID: PMC7606562 DOI: 10.1016/j.mce.2020.110912] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/14/2020] [Accepted: 06/06/2020] [Indexed: 12/19/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is an ancestral molecule that was isolated from sheep hypothalamic extracts based on its action to stimulate cAMP production by pituitary cell cultures. PACAP is one of a number of ligands that coordinate with GnRH to control reproduction. While initially viewed as a hypothalamic releasing factor, PACAP and its receptors are widely distributed, and there is growing evidence that PACAP functions as a paracrine/autocrine regulator in the CNS, pituitary, gonads and placenta, among other tissues. This review will summarize current knowledge concerning the expression and function of PACAP in the hypothalamic-pituitary-gonadal axis with special emphasis on its role in pituitary function in the fetus and newborn.
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Affiliation(s)
- Stephen J Winters
- Division of Endocrinology, Metabolism and Diabetes, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
| | - Joseph P Moore
- Division of Endocrinology, Metabolism and Diabetes, University of Louisville School of Medicine, Louisville, KY, 40202, USA; Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
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Rudecki AP, Gray SL. PACAP in the Defense of Energy Homeostasis. Trends Endocrinol Metab 2016; 27:620-632. [PMID: 27166671 DOI: 10.1016/j.tem.2016.04.008] [Citation(s) in RCA: 34] [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: 02/16/2016] [Revised: 04/12/2016] [Accepted: 04/12/2016] [Indexed: 11/23/2022]
Abstract
The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) mediates diverse physiology from neuroprotection to thermoregulation. PACAP is well established as a master regulator of the stress response, regulating psychological and physiological equilibrium via the autonomic nervous system. Neuroanatomical and functional evidence support a role for PACAP in energy metabolism, including thermogenesis, activity, mobilization of energy stores, and appetite. Through integration of this evidence we suggest PACAP be included in the growing list of neuropeptides that mediate energy homeostasis. Future work to uncover the intricacies of PACAP expression and the molecular pathways responsible for PACAP signaling may show potential for this neuropeptide as a therapeutic target as well as further elucidate the complex neuroanatomical networks involved in defending energy balance.
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Affiliation(s)
- Alexander P Rudecki
- Northern Medical Program, University of Northern British Columbia, 3333 University Way, Prince George BC, V2N 4Z9, Canada
| | - Sarah L Gray
- Northern Medical Program, University of Northern British Columbia, 3333 University Way, Prince George BC, V2N 4Z9, Canada.
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Mansouri S, Lietzau G, Lundberg M, Nathanson D, Nyström T, Patrone C. Pituitary Adenlylate Cyclase Activating Peptide Protects Adult Neural Stem Cells from a Hypoglycaemic milieu. PLoS One 2016; 11:e0156867. [PMID: 27305000 PMCID: PMC4909203 DOI: 10.1371/journal.pone.0156867] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 05/19/2016] [Indexed: 12/25/2022] Open
Abstract
Hypoglycaemia is a common side-effect of glucose-lowering therapies for type-2 diabetic patients, which may cause cognitive/neurological impairment. Although the effects of hypoglycaemia in the brain have been extensively studied in neurons, how hypoglycaemia impacts the viability of adult neural stem cells (NSCs) has been poorly investigated. In addition, the cellular and molecular mechanisms of how hypoglycaemia regulates NSCs survival have not been characterized. Recent work others and us have shown that the pituitary adenylate cyclase-activating polypeptide (PACAP) and the glucagon-like peptide-1 receptor (GLP-1R) agonist Exendin-4 stimulate NSCs survival against glucolipoapoptosis. The aim of this study was to establish an in vitro system where to study the effects of hypoglycaemia on NSC survival. Furthermore, we determine the potential role of PACAP and Exendin-4 in counteracting the effect of hypoglycaemia. A hypoglycaemic in vitro milieu was mimicked by exposing subventricular zone-derived NSC to low levels of glucose. Moreover, we studied the potential involvement of apoptosis and endoplasmic reticulum stress by quantifying protein levels of Bcl-2, cleaved caspase-3 and mRNA levels of CHOP. We show that PACAP via PAC-1 receptor and PKA activation counteracts impaired NSC viability induced by hypoglycaemia. The protective effect induced by PACAP correlated with endoplasmic reticulum stress, Exendin-4 was ineffective. The results show that hypoglycaemia decreases NSC viability and that this effect can be substantially counteracted by PACAP via PAC-1 receptor activation. The data supports a potential therapeutic role of PAC-1 receptor agonists for the treatment of neurological complications, based on neurogenesis impairment by hypoglycaemia.
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Affiliation(s)
- Shiva Mansouri
- Department of Clinical Science and Education, Södersjukhuset, Internal Medicine, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
| | - Grazyna Lietzau
- Department of Clinical Science and Education, Södersjukhuset, Internal Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Mathias Lundberg
- Department of Clinical Science and Education, Södersjukhuset, Internal Medicine, Karolinska Institutet, Stockholm, Sweden
| | - David Nathanson
- Department of Clinical Science and Education, Södersjukhuset, Internal Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Thomas Nyström
- Department of Clinical Science and Education, Södersjukhuset, Internal Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Cesare Patrone
- Department of Clinical Science and Education, Södersjukhuset, Internal Medicine, Karolinska Institutet, Stockholm, Sweden
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Nakata M, Zhang B, Yang Y, Okada T, Shintani N, Hashimoto H, Yada T. High-Fat Diet Augments VPAC1 Receptor-Mediated PACAP Action on the Liver, Inducing LAR Expression and Insulin Resistance. J Diabetes Res 2016; 2016:9321395. [PMID: 28044141 PMCID: PMC5156820 DOI: 10.1155/2016/9321395] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/26/2016] [Accepted: 11/13/2016] [Indexed: 11/21/2022] Open
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) acts on multiple processes of glucose and energy metabolism. PACAP potentiates insulin action in adipocytes and insulin release from pancreatic β-cells, thereby enhancing glucose tolerance. Contrary to these effects at organ levels, PACAP null mice exhibit hypersensitivity to insulin. However, this apparent discrepancy remains to be solved. We aimed to clarify the mechanism underlying the antidiabetic phenotype of PACAP null mice. Feeding with high-fat diet (HFD) impaired insulin sensitivity and glucose tolerance in wild type mice, whereas these changes were prevented in PACAP null mice. HFD also impaired insulin-induced Akt phosphorylation in the liver in wild type mice, but not in PACAP null mice. Using GeneFishing method, HFD increased the leukocyte common antigen-related (LAR) protein tyrosine phosphatase in the liver in wild type mice. Silencing of LAR restored the insulin signaling in the liver of HFD mice. Moreover, the increased LAR expression by HFD was prevented in PACAP null mice. HFD increased the expression of VPAC1 receptor (VPAC1-R), one of three PACAP receptors, in the liver of wild type mice. These data indicate that PACAP-VPAC1-R signaling induces LAR expression and insulin resistance in the liver of HFD mice. Antagonism of VPAC1-R may prevent progression of HFD-induced insulin resistance in the liver, providing a novel antidiabetic strategy.
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MESH Headings
- Animals
- Diet, High-Fat/adverse effects
- Gene Expression/drug effects
- Hypoglycemic Agents
- Insulin Resistance
- Liver/chemistry
- Liver/drug effects
- Liver/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Inbred ICR
- Mice, Knockout
- Pituitary Adenylate Cyclase-Activating Polypeptide/deficiency
- Pituitary Adenylate Cyclase-Activating Polypeptide/genetics
- Pituitary Adenylate Cyclase-Activating Polypeptide/pharmacology
- RNA, Messenger/analysis
- Receptor-Like Protein Tyrosine Phosphatases, Class 2/genetics
- Receptors, Vasoactive Intestinal Polypeptide, Type I/antagonists & inhibitors
- Receptors, Vasoactive Intestinal Polypeptide, Type I/genetics
- Receptors, Vasoactive Intestinal Polypeptide, Type I/physiology
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Affiliation(s)
- Masanori Nakata
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi 329-0498, Japan
| | - Boyang Zhang
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi 329-0498, Japan
| | - Yifei Yang
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi 329-0498, Japan
| | - Takashi Okada
- Department of Biochemistry and Molecular Biology, Division of Gene Therapy, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo 113-8603, Japan
| | - Norihito Shintani
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hitoshi Hashimoto
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
- Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka 565-0871, Japan
- Division of Bioscience, Institute for Datability Science, Osaka University, Suita, Osaka 565-0871, Japan
| | - Toshihiko Yada
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi 329-0498, Japan
- *Toshihiko Yada:
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Sanlioglu AD, Karacay B, Balci MK, Griffith TS, Sanlioglu S. Therapeutic potential of VIP vs PACAP in diabetes. J Mol Endocrinol 2012; 49:R157-67. [PMID: 22991228 DOI: 10.1530/jme-12-0156] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Type 2 diabetes (T2D) is characterized by chronic insulin resistance and a progressive decline in beta-cell function. Although rigorous glucose control can reduce morbidity and mortality associated with diabetes, achieving optimal long-term glycemic control remains to be accomplished in many diabetic patients. As beta-cell mass and function inevitably decline in T2D, exogenous insulin administration is almost unavoidable as a final outcome despite the use of oral antihyperglycemic agents in many diabetic patients. Pancreatic islet cell death, but not the defect in new islet formation or beta-cell replication, has been blamed for the decrease in beta-cell mass observed in T2D patients. Thus, therapeutic approaches designed to protect islet cells from apoptosis could significantly improve the management of T2D, because of its potential to reverse diabetes not just ameliorate glycemia. Therefore, an ideal beta-cell-preserving agent is expected to protect beta cells from apoptosis and stimulate postprandial insulin secretion along with increasing beta-cell replication and/or islet neogenesis. One such potential agent, the islet endocrine neuropeptide vasoactive intestinal peptide (VIP) strongly stimulates postprandial insulin secretion. Because of its broad spectrum of biological functions such as acting as a potent anti-inflammatory factor through suppression of Th1 immune response, and induction of immune tolerance via regulatory T cells, VIP has emerged as a promising therapeutic agent for the treatment of many autoimmune diseases including diabetes.
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Affiliation(s)
- Ahter D Sanlioglu
- Human Gene and Cell Therapy Center, Akdeniz University Hospitals and Clinics, B Block, 1st floor, Campus, Antalya 07058, Turkey
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Harmar AJ, Fahrenkrug J, Gozes I, Laburthe M, May V, Pisegna JR, Vaudry D, Vaudry H, Waschek JA, Said SI. Pharmacology and functions of receptors for vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide: IUPHAR review 1. Br J Pharmacol 2012; 166:4-17. [PMID: 22289055 DOI: 10.1111/j.1476-5381.2012.01871.x] [Citation(s) in RCA: 331] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are members of a superfamily of structurally related peptide hormones that includes glucagon, glucagon-like peptides, secretin, gastric inhibitory peptide (GIP) and growth hormone-releasing hormone (GHRH). VIP and PACAP exert their actions through three GPCRs - PAC(1) , VPAC(1) and VPAC(2) - belonging to class B (also referred to as class II, or secretin receptor-like GPCRs). This family comprises receptors for all peptides structurally related to VIP and PACAP, and also receptors for parathyroid hormone, corticotropin-releasing factor, calcitonin and related peptides. PAC(1) receptors are selective for PACAP, whereas VPAC(1) and VPAC(2) respond to both VIP and PACAP with high affinity. VIP and PACAP play diverse and important roles in the CNS, with functions in the control of circadian rhythms, learning and memory, anxiety and responses to stress and brain injury. Recent genetic studies also implicate the VPAC(2) receptor in susceptibility to schizophrenia and the PAC(1) receptor in post-traumatic stress disorder. In the periphery, VIP and PACAP play important roles in the control of immunity and inflammation, the control of pancreatic insulin secretion, the release of catecholamines from the adrenal medulla and as co-transmitters in autonomic and sensory neurons. This article, written by members of the International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature and Drug Classification (NC-IUPHAR) subcommittee on receptors for VIP and PACAP, confirms the existing nomenclature for these receptors and reviews our current understanding of their structure, pharmacology and functions and their likely physiological roles in health and disease. More detailed information has been incorporated into newly revised pages in the IUPHAR database (http://www.iuphar-db.org/DATABASE/FamilyMenuForward?familyId=67).
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Moody TW, Ito T, Osefo N, Jensen RT. VIP and PACAP: recent insights into their functions/roles in physiology and disease from molecular and genetic studies. Curr Opin Endocrinol Diabetes Obes 2011; 18:61-7. [PMID: 21157320 PMCID: PMC3075877 DOI: 10.1097/med.0b013e328342568a] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE OF REVIEW Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) as well as the three classes of G-protein-coupled receptors mediating their effects, are widely distributed in the central nervous system (CNS) and peripheral tissues. These peptides are reported to have many effects in different tissues, which are physiological or pharmacological, and which receptor mediates which effect, has been difficult to determine, primarily due to lack of potent, stable, selective agonists/antagonists. Recently the use of animals with targeted knockout of the peptide or a specific receptor has provided important insights into their role in normal physiology and disease states. RECENT FINDINGS During the review period, considerable progress and insights has occurred in the understanding of the role of VIP/PACAP as well as their receptors in a number of different disorders/areas. Particularly, insights into their roles in energy metabolism, glucose regulation, various gastrointestinal processes including gastrointestinal inflammatory conditions and motility and their role in the CNS as well as CNS diseases has greatly expanded. SUMMARY PACAP/VIP as well as their three classes of receptors are important in many physiological/pathophysiological processes, some of which are identified in these studies using knockout animals. These studies may lead to new novel treatment approaches. Particularly important are their roles in glucose metabolism and on islets leading to possible novel approaches in diabetes; their novel anti-inflammatory, cytoprotective effects, their CNS neuroprotective effects, and their possible roles in diseases such as schizophrenia and chronic depression.
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Affiliation(s)
- Terry W. Moody
- Department of Health and Human Services, National Cancer Institute Office of the Director, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Tetsuhide Ito
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan
| | - Nuramy Osefo
- Department of Health and Human Services, National Cancer Institute Office of the Director, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Robert T. Jensen
- Digestive Diseases Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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Vaudry D, Falluel-Morel A, Bourgault S, Basille M, Burel D, Wurtz O, Fournier A, Chow BKC, Hashimoto H, Galas L, Vaudry H. Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery. Pharmacol Rev 2009; 61:283-357. [DOI: 10.1124/pr.109.001370] [Citation(s) in RCA: 829] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Ahrén B. Role of pituitary adenylate cyclase-activating polypeptide in the pancreatic endocrine system. Ann N Y Acad Sci 2009; 1144:28-35. [PMID: 19076360 DOI: 10.1196/annals.1418.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In the pancreatic islets, pituitary adenylate cyclase-activating polypeptide (PACAP) is expressed in beta cells and autonomic nerve terminals; the majority of these nerve terminals are parasympathetic. PACAP binds to three types of G protein-coupled receptors (GPCRs): VPAC1 receptors, VPAC2 receptors, and PAC1 receptors. All these receptor types are expressed in pancreatic islets. PACAP stimulates insulin and glucagon secretion. These actions are achieved in part through increased formation of cAMP after activation of adenylate cyclase and in part through increase in cytosolic calcium, achieved through increase in calcium uptake and release from intracellular calcium stores. Deletion of PAC1 receptors or VPAC2 receptors results in impaired insulin secretion and glucose intolerance. Studies in PAC1 receptor gene deleted mice have suggested that PACAP may be of physiological importance in mediating prandial insulin secretion and in contributing to the glucagon response to hypoglycemia. Animal studies have also suggested that activation of the receptors, in particular VPAC2 receptors, may be used as a therapeutic approach for the treatment of type 2 diabetes. Hence, PACAP is an islet neuropeptide with a potential role in islet physiology and as a basis for development of islet-promoting therapy in type 2 diabetes.
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Affiliation(s)
- Bo Ahrén
- Department of Clinical Sciences, Division of Medicine, Lund University, Lund, Sweden.
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13
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Waterfield T, Gloyn AL. Monogenic β-cell dysfunction in children: clinical phenotypes, genetic etiology and mutational pathways. ACTA ACUST UNITED AC 2008. [DOI: 10.2217/17455111.2.4.517] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Monogenic diabetes accounts for 1–2% of all cases of diabetes mellitus and presentation is often in childhood. Recognizing the clinical features of monogenic β-cell dysfunction prevents misdiagnosis and allows for more effective management and genetic counseling. Monogenic β-cell dysfunction is a diverse collection of clinical phenotypes underpinned by common mutational pathways. Mutations affecting the glycolytic glucokinase enzyme, the mitochondria, the KATP channels and transcription factors have been known for some time. Until recently, the role of endoplasmic reticulum stress was underestimated in the pathogenesis of diabetes. It is becoming increasingly clear that endoplasmic reticulum stress is an important etiological factor in the development of monogenic and polygenic diabetes. In this article, we aim to define the etiology of pediatric monogenic β-cell dysfunction and provide guidance on the investigation and management of children presenting with monogenic β-cell dysfunction.
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Affiliation(s)
- Thomas Waterfield
- Diabetes Research Laboratories, Oxford Centre for Diabetes Endocrinology & Metabolism, Churchill Hospital, Old Road, Headington, Oxford, OX3 7LJ, UK
| | - Anna L Gloyn
- Diabetes Research Laboratories, Oxford Centre for Diabetes Endocrinology & Metabolism, Churchill Hospital, Old Road, Headington, Oxford, OX3 7LJ, UK
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14
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Adams BA, Gray SL, Isaac ER, Bianco AC, Vidal-Puig AJ, Sherwood NM. Feeding and metabolism in mice lacking pituitary adenylate cyclase-activating polypeptide. Endocrinology 2008; 149:1571-80. [PMID: 18162530 PMCID: PMC2276722 DOI: 10.1210/en.2007-0515] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Disruption of the pituitary adenylate cyclase-activating polypeptide (PACAP) gene in mice has demonstrated a role for this highly conserved neuropeptide in the regulation of metabolism and temperature control. Localization of PACAP neurons within hypothalamic nuclei that regulate appetite suggest PACAP may affect feeding and thus energy balance. We used PACAP-null mice to address this question, examining both food intake and energy expenditure. PACAP-null mice were leaner than wild-type littermates due to decreased adiposity and displayed increased insulin sensitivity. The lean phenotype in the PACAP-null mice was completely eliminated if animals were fed a high-fat diet or housed near thermoneutrality (28 C). Further metabolic analyses of PACAP-null mice housed at 21 C indicated that the reduced body weight could not be explained by decreased food intake, increased metabolic rate, or increased locomotor activity. The thyroid hormone axis of PACAP-null mice was affected, because mRNA levels of hypothalamic TRH and brown adipose tissue type 2 deiodinase were reduced in PACAP-null mice housed at room temperature, and brain deiodinase activity was lower in PACAP-null mice after an acute cold challenge compared with wild-type controls. These results demonstrate that PACAP is not required for the regulation of food intake yet is necessary to maintain normal energy homeostasis, likely playing a role in central cold-sensing mechanisms.
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Affiliation(s)
- Bruce A Adams
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
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Sherwood NM, Adams BA, Isaac ER, Wu S, Fradinger EA. Knocked down and out: PACAP in development, reproduction and feeding. Peptides 2007; 28:1680-7. [PMID: 17467121 DOI: 10.1016/j.peptides.2007.03.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Accepted: 03/15/2007] [Indexed: 11/20/2022]
Abstract
One approach to understanding the role of PACAP in vivo is to knockdown the translation of PACAP mRNA to protein or to knock out the PACAP gene by targeted disruption. In this paper, we review the effect of PACAP knockdown with morpholinos on early brain development in zebrafish. Also reviewed is the role of PACAP at several stages of reproduction as assessed in mice with a disrupted PACAP gene. New data are presented to analyze PACAP's action in energy homeostasis (body mass, food intake, endocrine parameters) using female PACAP-null mice. The evidence suggests PACAP is important for brain development in zebrafish and is required for normal reproduction, but not for body mass or food intake in mice maintained near thermoneutrality.
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Affiliation(s)
- Nancy M Sherwood
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5, Canada.
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Winzell MS, Ahrén B. Role of VIP and PACAP in islet function. Peptides 2007; 28:1805-13. [PMID: 17559974 DOI: 10.1016/j.peptides.2007.04.024] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 04/16/2007] [Accepted: 04/24/2007] [Indexed: 01/09/2023]
Abstract
Vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are two closely related neuropeptides that are expressed in islets and in islet parasympathetic nerves. Both peptides bind to their common G-protein-coupled receptors, VPAC1 and VPAC2, and PACAP, in addition to the specific receptor PAC1, all three of which are expressed in islets. VIP and PACAP stimulate insulin secretion in a glucose-dependent manner and they both also stimulate glucagon secretion. This action is achieved through increased formation of cAMP after activation of adenylate cyclase and stimulation of extracellular calcium uptake. Deletion of PAC1 receptors or VPAC2 receptors results in glucose intolerance. These peptides may be of importance in mediating prandial insulin secretion and the glucagon response to hypoglycemia. Animal studies have also suggested that activation of the receptors, in particular VPAC2 receptors, may be used as a therapeutic approach for the treatment of type 2 diabetes. This review summarizes the current knowledge of the potential role of VIP and PACAP in islet function.
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Affiliation(s)
- Maria Sörhede Winzell
- Department of Clinical Sciences, Division of Medicine, Lund University, BMC, B11, SE-221 84 Lund, Sweden.
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Yamaguchi N, Minassian TR, Yamaguchi S. Effects of PACAP(1-27) on the canine endocrine pancreas in vivo: interaction with cholinergic mechanism. Can J Physiol Pharmacol 2003; 81:720-9. [PMID: 12897820 DOI: 10.1139/y03-067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of the present study was to characterize the effects of pituitary adenylate cyclase activating polypeptide (PACAP) on the endocrine pancreas in anesthetized dogs. PACAP(1-27) and a PACAP receptor (PAC(1)) blocker, PACAP(6-27), were locally administered to the pancreas. PACAP(1-27) (0.005-5 microg) increased basal insulin and glucagon secretion in a dose-dependent manner. PACAP(6-27) (200 microg) blocked the glucagon response to PACAP(1-27) (0.5 microg) by about 80%, while the insulin response remained unchanged. With a higher dose of PACAP(6-27) (500 microg), both responses to PACAP(1-27) were inhibited by more than 80%. In the presence of atropine with an equivalent dose (128.2 microg) of PACAP(6-27) (500 microg) on a molar basis, the insulin response to PACAP(1-27) was diminished by about 20%, while the glucagon response was enhanced by about 80%. The PACAP(1-27)-induced increase in pancreatic venous blood flow was blocked by PACAP(6-27) but not by atropine. The study suggests that the endocrine secretagogue effect of PACAP(1-27) is primarily mediated by the PAC(1) receptor, and that PACAP(1-27) may interact with muscarinic receptor function in PACAP-induced insulin and glucagon secretion in the canine pancreas in vivo.
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Affiliation(s)
- Nobuharu Yamaguchi
- Groupe de recherche sur le système nerveux autonome (GRSNA), Faculté de pharmacie, Université de Montréal, Montréal, QC H3C 3J7, Canada.
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