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Jeeyavudeen MS, Mathiyalagan N, Fernandez James C, Pappachan JM. Tumor metabolism in pheochromocytomas: clinical and therapeutic implications. EXPLORATION OF TARGETED ANTI-TUMOR THERAPY 2024; 5:349-373. [PMID: 38745767 PMCID: PMC11090696 DOI: 10.37349/etat.2024.00222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/27/2023] [Indexed: 05/16/2024] Open
Abstract
Pheochromocytomas and paragangliomas (PPGLs) have emerged as one of the most common endocrine tumors. It epitomizes fascinating crossroads of genetic, metabolic, and endocrine oncology, providing a canvas to explore the molecular intricacies of tumor biology. Predominantly rooted in the aberration of metabolic pathways, particularly the Krebs cycle and related enzymatic functionalities, PPGLs manifest an intriguing metabolic profile, highlighting elevated levels of oncometabolites like succinate and fumarate, and furthering cellular malignancy and genomic instability. This comprehensive review aims to delineate the multifaceted aspects of tumor metabolism in PPGLs, encapsulating genetic factors, oncometabolites, and potential therapeutic avenues, thereby providing a cohesive understanding of metabolic disturbances and their ramifications in tumorigenesis and disease progression. Initial investigations into PPGLs metabolomics unveiled a stark correlation between specific genetic mutations, notably in the succinate dehydrogenase complex (SDHx) genes, and the accumulation of oncometabolites, establishing a pivotal role in epigenetic alterations and hypoxia-inducible pathways. By scrutinizing voluminous metabolic studies and exploiting technologies, novel insights into the metabolic and genetic aspects of PPGLs are perpetually being gathered elucidating complex interactions and molecular machinations. Additionally, the exploration of therapeutic strategies targeting metabolic abnormalities has burgeoned harboring potential for innovative and efficacious treatment modalities. This review encapsulates the profound metabolic complexities of PPGLs, aiming to foster an enriched understanding and pave the way for future investigations and therapeutic innovations in managing these metabolically unique tumors.
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Affiliation(s)
| | - Navin Mathiyalagan
- Department of Medical Oncology, Nottingham University Hospitals NHS Trust, NG5 1PB Nottingham, UK
| | - Cornelius Fernandez James
- Department of Endocrinology & Metabolism, Pilgrim Hospital, United Lincolnshire Hospitals NHS Trust, PE21 9QS Boston, UK
| | - Joseph M. Pappachan
- Department of Endocrinology and Metabolism, Lancashire Teaching Hospitals NHS Trust, PR2 9HT Preston, UK
- Faculty of Science, Manchester Metropolitan University, M15 6BH Manchester, UK
- Faculty of Biology, Medicine, and Health, The University of Manchester, M13 9PL Manchester, UK
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2
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Pandher PK, Rahim Y, Timms KP, Filatov E, Short LI, Gray SL. Reference gene recommendations and PACAP receptor expression in murine sympathetic ganglia of the autonomic nervous system that innervate adipose tissues after chronic cold exposure. J Neuroendocrinol 2023; 35:e13313. [PMID: 37404042 DOI: 10.1111/jne.13313] [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: 11/04/2022] [Revised: 06/01/2023] [Accepted: 06/04/2023] [Indexed: 07/06/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is an important regulator of the stress response in mammals, influencing both the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS). PACAP has been reported to influence energy homeostasis, including adaptive thermogenesis, an energy burning process in adipose tissue regulated by the SNS in response to cold stress and overfeeding. While research suggests PACAP acts centrally at the level of the hypothalamus, knowledge of PACAP's role within the sympathetic nerves innervating adipose tissues in response to metabolic stressors is limited. This work shows, for the first time, gene expression of PACAP receptors in stellate ganglia and highlights some differential expression with housing temperature. Additionally, we present our dissection protocol, analysis of tyrosine hydroxylase gene expression as a molecular biomarker for catecholamine producing tissue and recommend three stable reference genes for the normalization of quantitative real time-polymerase chain reaction (qRT-PCR) data when working with this tissue. This study adds to information about neuropeptide receptor expression in peripheral ganglia of the sympathetic nervous system innervating adipose tissue and provides insight into PACAP's role in the regulation of energy metabolism.
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Affiliation(s)
- Parleen K Pandher
- Northern Medical Program, Division of Medical Sciences, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Yamna Rahim
- Northern Medical Program, Division of Medical Sciences, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Katherine P Timms
- Northern Medical Program, Division of Medical Sciences, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Ekaterina Filatov
- Northern Medical Program, Division of Medical Sciences, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Landon I Short
- Northern Medical Program, Division of Medical Sciences, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Sarah L Gray
- Northern Medical Program, Division of Medical Sciences, University of Northern British Columbia, Prince George, British Columbia, Canada
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3
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Bauer MB, Currie KPM. Serotonin and the serotonin transporter in the adrenal gland. VITAMINS AND HORMONES 2023; 124:39-78. [PMID: 38408804 PMCID: PMC11217909 DOI: 10.1016/bs.vh.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
The adrenal glands are key components of the mammalian endocrine system, helping maintain physiological homeostasis and the coordinated response to stress. Each adrenal gland has two morphologically and functionally distinct regions, the outer cortex and inner medulla. The cortex is organized into three concentric zones which secrete steroid hormones, including aldosterone and cortisol. Neural crest-derived chromaffin cells in the medulla are innervated by preganglionic sympathetic neurons and secrete catecholamines (epinephrine, norepinephrine) and neuropeptides into the bloodstream, thereby functioning as the neuroendocrine arm of the sympathetic nervous system. In this article we review serotonin (5-HT) and the serotonin transporter (SERT; SLC6A4) in the adrenal gland. In the adrenal cortex, 5-HT, primarily sourced from resident mast cells, acts as a paracrine signal to stimulate aldosterone and cortisol secretion through 5-HT4/5-HT7 receptors. Medullary chromaffin cells contain a small amount of 5-HT due to SERT-mediated uptake and express 5-HT1A receptors which inhibit secretion. The atypical mechanism of the 5-HT1A receptors and interaction with SERT fine tune this autocrine pathway to control stress-evoked catecholamine secretion. Receptor-independent signaling by SERT/intracellular 5-HT modulates the amount and kinetics of transmitter release from single vesicle fusion events. SERT might also influence stress-evoked upregulation of tyrosine hydroxylase transcription. Transient signaling via 5-HT3 receptors during embryonic development can limit the number of chromaffin cells found in the mature adrenal gland. Together, this emerging evidence suggests that the adrenal medulla is a peripheral hub for serotonergic control of the sympathoadrenal stress response.
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Affiliation(s)
- Mary Beth Bauer
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, South Broadway, Camden, NJ, United States
| | - Kevin P M Currie
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, South Broadway, Camden, NJ, United States.
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4
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Guérineau NC. Adaptive remodeling of the stimulus-secretion coupling: Lessons from the 'stressed' adrenal medulla. VITAMINS AND HORMONES 2023; 124:221-295. [PMID: 38408800 DOI: 10.1016/bs.vh.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Stress is part of our daily lives and good health in the modern world is offset by unhealthy lifestyle factors, including the deleterious consequences of stress and associated pathologies. Repeated and/or prolonged stress may disrupt the body homeostasis and thus threatens our lives. Adaptive processes that allow the organism to adapt to new environmental conditions and maintain its homeostasis are therefore crucial. The adrenal glands are major endocrine/neuroendocrine organs involved in the adaptive response of the body facing stressful situations. Upon stress episodes and in response to activation of the sympathetic nervous system, the first adrenal cells to be activated are the neuroendocrine chromaffin cells located in the medullary tissue of the adrenal gland. By releasing catecholamines (mainly epinephrine and to a lesser extent norepinephrine), adrenal chromaffin cells actively contribute to the development of adaptive mechanisms, in particular targeting the cardiovascular system and leading to appropriate adjustments of blood pressure and heart rate, as well as energy metabolism. Specifically, this chapter covers the current knowledge as to how the adrenal medullary tissue remodels in response to stress episodes, with special attention paid to chromaffin cell stimulus-secretion coupling. Adrenal stimulus-secretion coupling encompasses various elements taking place at both the molecular/cellular and tissular levels. Here, I focus on stress-driven changes in catecholamine biosynthesis, chromaffin cell excitability, synaptic neurotransmission and gap junctional communication. These signaling pathways undergo a collective and finely-tuned remodeling, contributing to appropriate catecholamine secretion and maintenance of body homeostasis in response to stress.
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Affiliation(s)
- Nathalie C Guérineau
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France.
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5
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Morales A, Mohan R, Chen X, Coffman BL, Bendahmane M, Watch L, West JL, Bakshi S, Traynor JR, Giovannucci DR, Kammermeier PJ, Axelrod D, Currie KP, Smrcka AV, Anantharam A. PACAP and acetylcholine cause distinct Ca2+ signals and secretory responses in chromaffin cells. J Gen Physiol 2023; 155:e202213180. [PMID: 36538657 PMCID: PMC9770323 DOI: 10.1085/jgp.202213180] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 09/22/2022] [Accepted: 11/18/2022] [Indexed: 12/24/2022] Open
Abstract
The adrenomedullary chromaffin cell transduces chemical messages into outputs that regulate end organ function throughout the periphery. At least two important neurotransmitters are released by innervating preganglionic neurons to stimulate exocytosis in the chromaffin cell-acetylcholine (ACh) and pituitary adenylate cyclase activating polypeptide (PACAP). Although PACAP is widely acknowledged as an important secretagogue in this system, the pathway coupling PACAP stimulation to chromaffin cell secretion is poorly understood. The goal of this study is to address this knowledge gap. Here, it is shown that PACAP activates a Gαs-coupled pathway that must signal through phospholipase C ε (PLCε) to drive Ca2+ entry and exocytosis. PACAP stimulation causes a complex pattern of Ca2+ signals in chromaffin cells, leading to a sustained secretory response that is kinetically distinct from the form stimulated by ACh. Exocytosis caused by PACAP is associated with slower release of peptide cargo than exocytosis stimulated by ACh. Importantly, only the secretory response to PACAP, not ACh, is eliminated in cells lacking PLCε expression. The data show that ACh and PACAP, acting through distinct signaling pathways, enable nuanced and variable secretory outputs from chromaffin cells.
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Affiliation(s)
- Alina Morales
- Department of Neurosciences, University of Toledo, Toledo, OH, USA
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Ramkumar Mohan
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Xiaohuan Chen
- Department of Neurosciences, University of Toledo, Toledo, OH, USA
| | | | | | - Lester Watch
- Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, NC, USA
| | - Joshua L. West
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Shreeya Bakshi
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - John R. Traynor
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | | | - Paul J. Kammermeier
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| | - Daniel Axelrod
- Department of Physics and LSA Biophysics, University of Michigan, Ann Arbor, MI, USA
| | - Kevin P.M. Currie
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Alan V. Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Arun Anantharam
- Department of Neurosciences, University of Toledo, Toledo, OH, USA
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Eiden LE, Hernández VS, Jiang SZ, Zhang L. Neuropeptides and small-molecule amine transmitters: cooperative signaling in the nervous system. Cell Mol Life Sci 2022; 79:492. [PMID: 35997826 PMCID: PMC11072502 DOI: 10.1007/s00018-022-04451-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 06/15/2022] [Accepted: 06/23/2022] [Indexed: 12/17/2022]
Abstract
Neuropeptides are expressed in cell-specific patterns throughout mammalian brain. Neuropeptide gene expression has been useful for clustering neurons by phenotype, based on single-cell transcriptomics, and for defining specific functional circuits throughout the brain. How neuropeptides function as first messengers in inter-neuronal communication, in cooperation with classical small-molecule amine transmitters (SMATs) is a current topic of systems neurobiology. Questions include how neuropeptides and SMATs cooperate in neurotransmission at the molecular, cellular and circuit levels; whether neuropeptides and SMATs always co-exist in neurons; where neuropeptides and SMATs are stored in the neuron, released from the neuron and acting, and at which receptors, after release; and how neuropeptides affect 'classical' transmitter function, both directly upon co-release, and indirectly, via long-term regulation of gene transcription and neuronal plasticity. Here, we review an extensive body of data about the distribution of neuropeptides and their receptors, their actions after neuronal release, and their function based on pharmacological and genetic loss- and gain-of-function experiments, that addresses these questions, fundamental to understanding brain function, and development of neuropeptide-based, and potentially combinatorial peptide/SMAT-based, neurotherapeutics.
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Affiliation(s)
- Lee E Eiden
- Section On Molecular Neuroscience, National Institute of Mental Health, Intramural Research Program, National Institutes of Health, 49 Convent Drive, Room 5A38, Bethesda, MD, 20892, USA.
| | - Vito S Hernández
- Department of Physiology, School of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| | - Sunny Z Jiang
- Section On Molecular Neuroscience, National Institute of Mental Health, Intramural Research Program, National Institutes of Health, 49 Convent Drive, Room 5A38, Bethesda, MD, 20892, USA
| | - Limei Zhang
- Department of Physiology, School of Medicine, National Autonomous University of Mexico, Mexico City, Mexico.
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7
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Lopez Ruiz JR, Ernst SA, Holz RW, Stuenkel EL. Basal and Stress-Induced Network Activity in the Adrenal Medulla In Vivo. Front Endocrinol (Lausanne) 2022; 13:875865. [PMID: 35795145 PMCID: PMC9250985 DOI: 10.3389/fendo.2022.875865] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/12/2022] [Indexed: 11/23/2022] Open
Abstract
The adrenal medulla plays a critical role in mammalian homeostasis and the stress response. It is populated by clustered chromaffin cells that secrete epinephrine or norepinephrine along with peptides into the bloodstream affecting distant target organs. Despite been heavily studied, the central control of adrenal medulla and in-situ spatiotemporal responsiveness remains poorly understood. For this work, we continuously monitored the electrical activity of individual adrenomedullary chromaffin cells in the living anesthetized rat using multielectrode arrays. We measured the chromaffin cell activity under basal and physiological stress conditions and characterized the functional micro-architecture of the adrenal medulla. Under basal conditions, chromaffin cells fired action potentials with frequencies between ~0.2 and 4 Hz. Activity was almost completely driven by sympathetic inputs coming through the splanchnic nerve. Chromaffin cells were organized into independent local networks in which cells fired in a specific order, with latencies from hundreds of microseconds to a few milliseconds. Electrical stimulation of the splanchnic nerve evoked almost exactly the same spatiotemporal firing patterns that occurred spontaneously. Hypoglycemic stress, induced by insulin administration resulted in increased activity of a subset of the chromaffin cells. In contrast, respiratory arrest induced by lethal anesthesia resulted in an increase in the activity of virtually all chromaffin cells before cessation of all activity. These results suggest a stressor-specific activation of adrenomedullary chromaffin cell networks and revealed a surprisingly complex electrical organization that likely reflects the dynamic nature of the adrenal medulla's neuroendocrine output during basal conditions and during different types of physiological stress.
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Affiliation(s)
- Jose R Lopez Ruiz
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Stephen A Ernst
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Ronald W Holz
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Edward L Stuenkel
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, United States
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
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8
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Boucher MN, May V, Braas KM, Hammack SE. PACAP orchestration of stress-related responses in neural circuits. Peptides 2021; 142:170554. [PMID: 33865930 PMCID: PMC8592028 DOI: 10.1016/j.peptides.2021.170554] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/31/2021] [Accepted: 04/09/2021] [Indexed: 02/06/2023]
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) is a pleiotropic polypeptide that can activate G protein-coupled PAC1, VPAC1, and VPAC2 receptors, and has been implicated in stress signaling. PACAP and its receptors are widely distributed throughout the nervous system and other tissues and can have a multitude of effects. Human and animal studies suggest that PACAP plays a role responding to a variety of threats and stressors. Here we review the roles of PACAP in several regions of the central nervous system (CNS) as they relate to several behavioral functions. For example, in the bed nucleus of the stria terminalis (BNST), PACAP is upregulated following chronic stress and may drive anxiety-like behavior. PACAP can also influence both the consolidation and expression of fear memories, as demonstrated by studies in several fear-related areas, such as the amygdala, hippocampus, and prefrontal cortex. PACAP can also mediate the emotional component of pain, as PACAP in the central nucleus of the amygdala (CeA) is able to decrease pain sensitivity thresholds. Outside of the central nervous system, PACAP may drive glucocorticoid release via enhanced hypothalamic-pituitary-adrenal axis activity and may participate in infection-induced stress responses. Together, this suggests that PACAP exerts effects on many stress-related systems and may be an important driver of emotional behavior.
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Affiliation(s)
- Melissa N Boucher
- Department of Psychological Science, University of Vermont, 2 Colchester Avenue, Burlington, VT, 05405, United States
| | - Victor May
- Department of Neurological Sciences, University of Vermont Larner College of Medicine, 149 Beaumont Avenue, Burlington, VT, 05405, United States.
| | - Karen M Braas
- Department of Neurological Sciences, University of Vermont Larner College of Medicine, 149 Beaumont Avenue, Burlington, VT, 05405, United States
| | - Sayamwong E Hammack
- Department of Psychological Science, University of Vermont, 2 Colchester Avenue, Burlington, VT, 05405, United States
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Harada K, Matsuoka H, Toyohira Y, Yanagawa Y, Inoue M. Mechanisms for establishment of GABA signaling in adrenal medullary chromaffin cells. J Neurochem 2021; 158:153-168. [PMID: 33704788 DOI: 10.1111/jnc.15345] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 03/05/2021] [Accepted: 03/07/2021] [Indexed: 11/26/2022]
Abstract
γ-Aminobutyric acid (GABA) is thought to play a paracrine role in adrenal medullary chromaffin (AMC) cells. Comparative physiological and immunocytochemical approaches were used to address the issue of how the paracrine function of GABA in AMC cells is established. GABAA receptor Cl- channel activities in AMC cells of rats and mice, where corticosterone is the major glucocorticoid, were much smaller than those in AMC cells of guinea-pigs and cattle, where cortisol is the major. The extent of enhancement of GABAA receptor α3 subunit expression in rat pheochromocytoma (PC12) cells by cortisol was larger than that by corticosterone in parallel with their glucocorticoid activities. Thus, the species difference in GABAA receptor expression may be ascribed to a difference in glucocorticoid activity between corticosterone and cortisol. GABAA receptor Cl- channel activity in mouse AMC cells was enhanced by allopregnanolone, as noted with that in guinea-pig AMC cells, and the enzymes involved in allopregnanolone production were immunohistochemically detected in the zona fasciculata in both mice and guinea pigs. The expression of glutamic acid decarboxylase 67 (GAD67), one of the GABA synthesizing enzymes, increased after birth, whereas GABAA receptors already developed at birth. Stimulation of pituitary adenylate cyclase-activating polypeptide (PACAP) receptors, but not nicotinic or muscarinic receptors, in PC12 cells, resulted in an increase in GAD67 expression in a protein-kinase A-dependent manner. The results indicate that glucocorticoid and PACAP are mainly responsible for the expressions of GABAA receptors and GAD67 involved in GABA signaling in AMC cells, respectively.
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Affiliation(s)
- Keita Harada
- Department of Cell and Systems Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Hidetada Matsuoka
- Department of Cell and Systems Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Yumiko Toyohira
- Department of Pharmacology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Masumi Inoue
- Department of Cell and Systems Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, Japan
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Milman A, Ventéo S, Bossu JL, Fontanaud P, Monteil A, Lory P, Guérineau NC. A sodium background conductance controls the spiking pattern of mouse adrenal chromaffin cells in situ. J Physiol 2021; 599:1855-1883. [PMID: 33450050 PMCID: PMC7986707 DOI: 10.1113/jp281044] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/04/2021] [Indexed: 12/11/2022] Open
Abstract
KEY POINTS Mouse chromaffin cells in acute adrenal slices exhibit two distinct spiking patterns, a repetitive mode and a bursting mode. A sodium background conductance operates at rest as demonstrated by the membrane hyperpolarization evoked by a low Na+ -containing extracellular saline. This sodium background current is insensitive to TTX, is not blocked by Cs+ ions and displays a linear I-V relationship at potentials close to chromaffin cell resting potential. Its properties are reminiscent of those of the sodium leak channel NALCN. In the adrenal gland, Nalcn mRNA is selectively expressed in chromaffin cells. The study fosters our understanding of how the spiking pattern of chromaffin cells is regulated and adds a sodium background conductance to the list of players involved in the stimulus-secretion coupling of the adrenomedullary tissue. ABSTRACT Chromaffin cells (CCs) are the master neuroendocrine units for the secretory function of the adrenal medulla and a finely-tuned regulation of their electrical activity is required for appropriate catecholamine secretion in response to the organismal demand. Here, we aim at deciphering how the spiking pattern of mouse CCs is regulated by the ion conductances operating near the resting membrane potential (RMP). At RMP, mouse CCs display a composite firing pattern, alternating between active periods composed of action potentials spiking with a regular or a bursting mode, and silent periods. RMP is sensitive to changes in extracellular sodium concentration, and a low Na+ -containing saline hyperpolarizes the membrane, regardless of the discharge pattern. This RMP drive reflects the contribution of a depolarizing conductance, which is (i) not blocked by tetrodotoxin or caesium, (ii) displays a linear I-V relationship between -110 and -40 mV, and (iii) is carried by cations with a conductance sequence gNa > gK > gCs . These biophysical attributes, together with the expression of the sodium-leak channel Nalcn transcript in CCs, state credible the contribution of NALCN. This inaugural report opens new research routes in the field of CC stimulus-secretion coupling, and extends the inventory of tissues in which NALCN is expressed to neuroendocrine glands.
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Affiliation(s)
- Alexandre Milman
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France.,LabEx "Ion Channel Science and Therapeutics", Montpellier, France
| | | | - Jean-Louis Bossu
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Strasbourg, France
| | - Pierre Fontanaud
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Arnaud Monteil
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France.,LabEx "Ion Channel Science and Therapeutics", Montpellier, France
| | - Philippe Lory
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France.,LabEx "Ion Channel Science and Therapeutics", Montpellier, France
| | - Nathalie C Guérineau
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France.,LabEx "Ion Channel Science and Therapeutics", Montpellier, France
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11
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Biran J, Gliksberg M, Shirat I, Swaminathan A, Levitas-Djerbi T, Appelbaum L, Levkowitz G. Splice-specific deficiency of the PTSD-associated gene PAC1 leads to a paradoxical age-dependent stress behavior. Sci Rep 2020; 10:9559. [PMID: 32533011 PMCID: PMC7292827 DOI: 10.1038/s41598-020-66447-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 05/19/2020] [Indexed: 02/06/2023] Open
Abstract
The pituitary adenylate cyclase-activating polypeptide receptor (PAC1, also known as ADCYAP1R1) is associated with post-traumatic stress disorder and modulation of stress response in general. Alternative splicing of PAC1 results in multiple gene products, which differ in their mode of signalling and tissue distribution. However, the roles of distinct splice variants in the regulation of stress behavior is poorly understood. Alternative splicing of a short exon, which is known as the "hop cassette", occurs during brain development and in response to stressful challenges. To examine the function of this variant, we generated a splice-specific zebrafish mutant lacking the hop cassette, which we designated 'hopless'. We show that hopless mutant larvae display increased anxiety-like behavior, including reduced dark exploration and impaired habituation to dark exposure. Conversely, adult hopless mutants displayed superior ability to rebound from an acute stressor, as they exhibited reduced anxiety-like responses to an ensuing novelty stress. We propose that the developmental loss of a specific PAC1 splice variant mimics prolonged mild stress exposure, which in the long term, predisposes the organism's stress response towards a resilient phenotype. Our study presents a unique genetic model demonstrating how early-life state of anxiety paradoxically correlates with reduced stress susceptibility in adulthood.
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Affiliation(s)
- Jakob Biran
- Department of Poultry and Aquaculture, Agricultural Research Organization, Rishon, Letziyon, 7528809, Israel.
| | - Michael Gliksberg
- Department of Molecular Cell Biology, Weizmann Institute of Science, PO Box 26, Rehovot, 7610001, Israel
| | - Ido Shirat
- Department of Molecular Cell Biology, Weizmann Institute of Science, PO Box 26, Rehovot, 7610001, Israel
| | - Amrutha Swaminathan
- Department of Molecular Cell Biology, Weizmann Institute of Science, PO Box 26, Rehovot, 7610001, Israel
| | - Talia Levitas-Djerbi
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Lior Appelbaum
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Gil Levkowitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, PO Box 26, Rehovot, 7610001, Israel.
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12
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Biran J, Gliksberg M, Shirat I, Swaminathan A, Levitas-Djerbi T, Appelbaum L, Levkowitz G. Splice-specific deficiency of the PTSD-associated gene PAC1 leads to a paradoxical age-dependent stress behavior. Sci Rep 2020. [PMID: 32533011 DOI: 10.1038/s41598-020-66447-2.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The pituitary adenylate cyclase-activating polypeptide receptor (PAC1, also known as ADCYAP1R1) is associated with post-traumatic stress disorder and modulation of stress response in general. Alternative splicing of PAC1 results in multiple gene products, which differ in their mode of signalling and tissue distribution. However, the roles of distinct splice variants in the regulation of stress behavior is poorly understood. Alternative splicing of a short exon, which is known as the "hop cassette", occurs during brain development and in response to stressful challenges. To examine the function of this variant, we generated a splice-specific zebrafish mutant lacking the hop cassette, which we designated 'hopless'. We show that hopless mutant larvae display increased anxiety-like behavior, including reduced dark exploration and impaired habituation to dark exposure. Conversely, adult hopless mutants displayed superior ability to rebound from an acute stressor, as they exhibited reduced anxiety-like responses to an ensuing novelty stress. We propose that the developmental loss of a specific PAC1 splice variant mimics prolonged mild stress exposure, which in the long term, predisposes the organism's stress response towards a resilient phenotype. Our study presents a unique genetic model demonstrating how early-life state of anxiety paradoxically correlates with reduced stress susceptibility in adulthood.
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Affiliation(s)
- Jakob Biran
- Department of Poultry and Aquaculture, Agricultural Research Organization, Rishon, Letziyon, 7528809, Israel.
| | - Michael Gliksberg
- Department of Molecular Cell Biology, Weizmann Institute of Science, PO Box 26, Rehovot, 7610001, Israel
| | - Ido Shirat
- Department of Molecular Cell Biology, Weizmann Institute of Science, PO Box 26, Rehovot, 7610001, Israel
| | - Amrutha Swaminathan
- Department of Molecular Cell Biology, Weizmann Institute of Science, PO Box 26, Rehovot, 7610001, Israel
| | - Talia Levitas-Djerbi
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Lior Appelbaum
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Gil Levkowitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, PO Box 26, Rehovot, 7610001, Israel.
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13
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TASK channels: channelopathies, trafficking, and receptor-mediated inhibition. Pflugers Arch 2020; 472:911-922. [DOI: 10.1007/s00424-020-02403-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/08/2020] [Accepted: 05/18/2020] [Indexed: 01/06/2023]
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14
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Carbone E, Borges R, Eiden LE, García AG, Hernández‐Cruz A. Chromaffin Cells of the Adrenal Medulla: Physiology, Pharmacology, and Disease. Compr Physiol 2019; 9:1443-1502. [DOI: 10.1002/cphy.c190003] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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15
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Intricacies of the Molecular Machinery of Catecholamine Biosynthesis and Secretion by Chromaffin Cells of the Normal Adrenal Medulla and in Pheochromocytoma and Paraganglioma. Cancers (Basel) 2019; 11:cancers11081121. [PMID: 31390824 PMCID: PMC6721535 DOI: 10.3390/cancers11081121] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 12/11/2022] Open
Abstract
The adrenal medulla is composed predominantly of chromaffin cells producing and secreting the catecholamines dopamine, norepinephrine, and epinephrine. Catecholamine biosynthesis and secretion is a complex and tightly controlled physiologic process. The pathways involved have been extensively studied, and various elements of the underlying molecular machinery have been identified. In this review, we provide a detailed description of the route from stimulus to secretion of catecholamines by the normal adrenal chromaffin cell compared to chromaffin tumor cells in pheochromocytomas. Pheochromocytomas are adrenomedullary tumors that are characterized by uncontrolled synthesis and secretion of catecholamines. This uncontrolled secretion can be partly explained by perturbations of the molecular catecholamine secretory machinery in pheochromocytoma cells. Chromaffin cell tumors also include sympathetic paragangliomas originating in sympathetic ganglia. Pheochromocytomas and paragangliomas are usually locally confined tumors, but about 15% do metastasize to distant locations. Histopathological examination currently poorly predicts future biologic behavior, thus long term postoperative follow-up is required. Therefore, there is an unmet need for prognostic biomarkers. Clearer understanding of the cellular mechanisms involved in the secretory characteristics of pheochromocytomas and sympathetic paragangliomas may offer one approach for the discovery of novel prognostic biomarkers for improved therapeutic targeting and monitoring of treatment or disease progression.
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16
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Guérineau NC. Cholinergic and peptidergic neurotransmission in the adrenal medulla: A dynamic control of stimulus‐secretion coupling. IUBMB Life 2019; 72:553-567. [DOI: 10.1002/iub.2117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 06/18/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Nathalie C. Guérineau
- IGFUniv. Montpellier, CNRS, INSERM Montpellier France
- LabEx “Ion Channel Science and Therapeutics” Montpellier France
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17
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Two ancient neuropeptides, PACAP and AVP, modulate motivated behavior at synapses in the extrahypothalamic brain: a study in contrast. Cell Tissue Res 2018; 375:103-122. [DOI: 10.1007/s00441-018-2958-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 11/05/2018] [Indexed: 01/24/2023]
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18
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Abstract
The brain hosts a vast and diverse repertoire of neuropeptides, a class of signalling molecules often described as neurotransmitters. Here I argue that this description entails a catalogue of misperceptions, misperceptions that feed into a narrative in which information processing in the brain can be understood only through mapping neuronal connectivity and by studying the transmission of electrically conducted signals through chemical synapses. I argue that neuropeptide signalling in the brain involves primarily autocrine, paracrine and neurohormonal mechanisms that do not depend on synaptic connectivity and that it is not solely dependent on electrical activity but on mechanisms analogous to secretion from classical endocrine cells. As in classical endocrine systems, to understand the role of neuropeptides in the brain, we must understand not only how their release is regulated, but also how their synthesis is regulated and how the sensitivity of their targets is regulated. We must also understand the full diversity of effects of neuropeptides on those targets, including their effects on gene expression.
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Affiliation(s)
- Gareth Leng
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Correspondence should be addressed to G Leng:
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19
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Sahu BS, Mahata S, Bandyopadhyay K, Mahata M, Avolio E, Pasqua T, Sahu C, Bandyopadhyay GK, Bartolomucci A, Webster NJG, Van Den Bogaart G, Fischer-Colbrie R, Corti A, Eiden LE, Mahata SK. Catestatin regulates vesicular quanta through modulation of cholinergic and peptidergic (PACAPergic) stimulation in PC12 cells. Cell Tissue Res 2018; 376:51-70. [PMID: 30467710 DOI: 10.1007/s00441-018-2956-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/30/2018] [Indexed: 12/23/2022]
Abstract
We have previously shown that the chromogranin A (CgA)-derived peptide catestatin (CST: hCgA352-372) inhibits nicotine-induced secretion of catecholamines from the adrenal medulla and chromaffin cells. In the present study, we seek to determine whether CST regulates dense core (DC) vesicle (DCV) quanta (catecholamine and chromogranin/secretogranin proteins) during acute (0.5-h treatment) or chronic (24-h treatment) cholinergic (nicotine) or peptidergic (PACAP, pituitary adenylyl cyclase activating polypeptide) stimulation of PC12 cells. In acute experiments, we found that both nicotine (60 μM) and PACAP (0.1 μM) decreased intracellular norepinephrine (NE) content and increased 3H-NE secretion, with both effects markedly inhibited by co-treatment with CST (2 μM). In chronic experiments, we found that nicotine and PACAP both reduced DCV and DC diameters and that this effect was likewise prevented by CST. Nicotine or CST alone increased expression of CgA protein and together elicited an additional increase in CgA protein, implying that nicotine and CST utilize separate signaling pathways to activate CgA expression. In contrast, PACAP increased expression of CgB and SgII proteins, with a further potentiation by CST. CST augmented the expression of tyrosine hydroxylase (TH) but did not increase intracellular NE levels, presumably due to its inability to cause post-translational activation of TH through serine phosphorylation. Co-treatment of CST with nicotine or PACAP increased quantal size, plausibly due to increased synthesis of CgA, CgB and SgII by CST. We conclude that CST regulates DCV quanta by acutely inhibiting catecholamine secretion and chronically increasing expression of CgA after nicotinic stimulation and CgB and SgII after PACAPergic stimulation.
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Affiliation(s)
- Bhavani Shankar Sahu
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA. .,Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0732, USA.
| | - Sumana Mahata
- California Institute of Technology, Pasadena, CA, USA
| | - Keya Bandyopadhyay
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0732, USA
| | - Manjula Mahata
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0732, USA
| | | | | | - Chinmayi Sahu
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Gautam K Bandyopadhyay
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0732, USA
| | - Alessandro Bartolomucci
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Nicholas J G Webster
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0732, USA.,VA San Diego Healthcare System, San Diego, CA, USA
| | | | | | - Angelo Corti
- IRCCS San Raffaele Scientific Institute, San Raffaele Vita-Salute University, Milan, Italy
| | - Lee E Eiden
- Section on Molecular Neuroscience, NIMH-IRP, Bethesda, MD, USA
| | - Sushil K Mahata
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0732, USA. .,VA San Diego Healthcare System, San Diego, CA, USA.
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20
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Byrne CJ, Khurana S, Kumar A, Tai TC. Inflammatory Signaling in Hypertension: Regulation of Adrenal Catecholamine Biosynthesis. Front Endocrinol (Lausanne) 2018; 9:343. [PMID: 30013513 PMCID: PMC6036303 DOI: 10.3389/fendo.2018.00343] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/07/2018] [Indexed: 12/24/2022] Open
Abstract
The immune system is increasingly recognized for its role in the genesis and progression of hypertension. The adrenal gland is a major site that coordinates the stress response via the hypothalamic-pituitary-adrenal axis and the sympathetic-adrenal system. Catecholamines released from the adrenal medulla function in the neuro-hormonal regulation of blood pressure and have a well-established link to hypertension. The immune system has an active role in the progression of hypertension and cytokines are powerful modulators of adrenal cell function. Adrenal medullary cells integrate neural, hormonal, and immune signals. Changes in adrenal cytokines during the progression of hypertension may promote blood pressure elevation by influencing catecholamine biosynthesis. This review highlights the potential interactions of cytokine signaling networks with those of catecholamine biosynthesis within the adrenal, and discusses the role of cytokines in the coordination of blood pressure regulation and the stress response.
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Affiliation(s)
- Collin J. Byrne
- Department of Biology, Laurentian University, Sudbury, ON, Canada
| | - Sandhya Khurana
- Medical Sciences Division, Northern Ontario School of Medicine, Sudbury, ON, Canada
| | - Aseem Kumar
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada
- Biomolecular Sciences Program, Laurentian University, Sudbury, ON, Canada
| | - T. C. Tai
- Department of Biology, Laurentian University, Sudbury, ON, Canada
- Medical Sciences Division, Northern Ontario School of Medicine, Sudbury, ON, Canada
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada
- Biomolecular Sciences Program, Laurentian University, Sudbury, ON, Canada
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21
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Nakamachi T, Kamata E, Tanigawa A, Konno N, Shioda S, Matsuda K. Distribution of pituitary adenylate cyclase-activating polypeptide 2 in zebrafish brain. Peptides 2018. [PMID: 29535004 DOI: 10.1016/j.peptides.2018.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a multipotent neuropeptide with an amino acid sequence that is well conserved among vertebrates. In teleosts, including zebrafish, the PACAP gene (adcyap1) has been duplicated to yield adcyap1a (coding PACAP1) and adcyap1b (coding PACAP2). This study aims to determine the distribution of these PACAPs and their mRNAs in zebrafish. We generated a zebrafish PACAP2-specific antibody. Using real-time PCR, we observed that adcyap1b mRNA was primarily localized in the brain, with the highest level in the telencephalon, followed by the diencephalon. Using immunostaining of brain tissue samples, PACAP2 immunoreactivity was observed mainly in the telencephalon, hypothalamus, and cerebellum, and the immunopositive fibers formed a line to the habenula. PACAP2-immunopositive cells were observed in the ventral and dorsal regions of the telencephalon and in the hypothalamic nucleus of the diencephalon in the colchicine-injected brain. This distribution of PACAP2 suggests its involvement in higher brain functions in teleosts, such as learning and cognition, as well as instinctive behaviors such as feeding and emotional regulation.
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Affiliation(s)
- Tomoya Nakamachi
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan.
| | - Eri Kamata
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
| | - Ayano Tanigawa
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
| | - Norifumi Konno
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
| | - Seiji Shioda
- Innovative Drug Discovery, Global Research Center for Innovative Life Science, Hoshi University, 4-41 Ebara 2-chome, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
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22
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Eiden LE, Jiang SZ. What's New in Endocrinology: The Chromaffin Cell. Front Endocrinol (Lausanne) 2018; 9:711. [PMID: 30564193 PMCID: PMC6288183 DOI: 10.3389/fendo.2018.00711] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/12/2018] [Indexed: 01/08/2023] Open
Abstract
Recent advances in understanding the intracellular and intercellular features of adrenal chromatin cells as stress transducers are reviewed here, along with their implications for endocrine function in other tissues and organs participating in endocrine regulation in the mammalian organism.
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23
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Old and emerging concepts on adrenal chromaffin cell stimulus-secretion coupling. Pflugers Arch 2017; 470:1-6. [PMID: 29110079 DOI: 10.1007/s00424-017-2082-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 10/19/2017] [Indexed: 10/18/2022]
Abstract
The chromaffin cells (CCs) of the adrenal medulla play a key role in the control of circulating catecholamines to adapt our body function to stressful conditions. A huge research effort over the last 35 years has converted these cells into the Escherichia coli of neurobiology. CCs have been the testing bench for the development of patch-clamp and amperometric recording techniques and helped clarify most of the known molecular mechanisms that regulate cell excitability, Ca2+ signals associated with secretion, and the molecular apparatus that regulates vesicle fusion. This special issue provides a state-of-the-art on the many well-known and unsolved questions related to the molecular processes at the basis of CC function. The issue is also the occasion to highlight the seminal work of Antonio G. García (Emeritus Professor at UAM, Madrid) who greatly contributed to the advancement of our present knowledge on CC physiology and pharmacology. All the contributors of the present issue are distinguished scientists who are either staff members, external collaborators, or friends of Prof. García.
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24
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Alejandre-García T, Peña-del Castillo JG, Hernández-Cruz A. GABAA receptor: a unique modulator of excitability, Ca2+ signaling, and catecholamine release of rat chromaffin cells. Pflugers Arch 2017; 470:67-77. [DOI: 10.1007/s00424-017-2080-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 01/12/2023]
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25
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Wolf K, Zarkua G, Chan SA, Sridhar A, Smith C. Spatial and activity-dependent catecholamine release in rat adrenal medulla under native neuronal stimulation. Physiol Rep 2017; 4:4/17/e12898. [PMID: 27597763 PMCID: PMC5027341 DOI: 10.14814/phy2.12898] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 07/25/2016] [Indexed: 11/24/2022] Open
Abstract
Neuroendocrine chromaffin cells of the adrenal medulla in rat receive excitatory synaptic input through anterior and posterior divisions of the sympathetic splanchnic nerve. Upon synaptic stimulation, the adrenal medulla releases the catecholamines, epinephrine, and norepinephrine into the suprarenal vein for circulation throughout the body. Under sympathetic tone, catecholamine release is modest. However, upon activation of the sympathoadrenal stress reflex, and increased splanchnic firing, adrenal catecholamine output increases dramatically. Moreover, specific stressors can preferentially increase release of either epinephrine (i.e., hypoglycemia) or norepinephrine (i.e., cold stress). The mechanism for this stressor-dependent segregated release of catecholamine species is not yet fully understood. We tested the hypothesis that stimulation of either division of the splanchnic selects for epinephrine over norepinephrine release. We introduce an ex vivo rat preparation that maintains native splanchnic innervation of the adrenal gland and we document experimental advantages and limitations of this preparation. We utilize fast scanning cyclic voltammetry to detect release of both epinephrine and norepinephrine from the adrenal medulla, and report that epinephrine and norepinephrine release are regulated spatially and in a frequency-dependent manner. We provide data to show that epinephrine is secreted preferentially from the periphery of the medulla and exhibits a higher threshold and steeper stimulus-secretion function than norepinephrine. Elevated stimulation of the whole nerve specifically enhances epinephrine release from the peripheral medulla. Our data further show that elimination of either division from stimulation greatly attenuated epinephrine release under elevated stimulation, while either division alone can largely support norepinephrine release.
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Affiliation(s)
- Kyle Wolf
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Georgy Zarkua
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Shyue-An Chan
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Arun Sridhar
- Bioelectronics Research and Development, GlaxoSmithKline, Stevenage, United Kingdom
| | - Corey Smith
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
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PACAP signaling in stress: insights from the chromaffin cell. Pflugers Arch 2017; 470:79-88. [PMID: 28965274 DOI: 10.1007/s00424-017-2062-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 10/18/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) was first identified in hypothalamus, based on its ability to elevate cyclic AMP in the anterior pituitary. PACAP has been identified as the adrenomedullary neurotransmitter in stress through a combination of ex vivo, in vivo, and in cellula experiments over the past two decades. PACAP causes catecholamine secretion, and activation of catecholamine biosynthetic enzymes, during episodes of stress in mammals. Features of PACAP signaling allowing stress transduction at the splanchnicoadrenomedullary synapse have yielded insights into the contrasting roles of acetylcholine's and PACAP's actions as first messengers at the chromaffin cell, via differential release at low and high rates of splanchnic nerve firing, and differential signaling pathway engagement leading to catecholamine secretion and chromaffin cell gene transcription. Secretion stimulated by PACAP, via calcium influx independent of action potential generation, is under active investigation in several laboratories both at the chromaffin cell and within autonomic ganglia of both the parasympathetic and sympathetic nervous systems. PACAP is a neurotransmitter important in stress transduction in the central nervous system as well, and is found at stress-transduction nuclei in brain including the paraventricular nucleus of hypothalamus, the amygdala and extended amygdalar nuclei, and the prefrontal cortex. The current status of PACAP as a master regulator of stress signaling in the nervous system derives fundamentally from the establishment of its role as the splanchnicoadrenomedullary transmitter in stress. Experimental elucidation of PACAP action at this synapse remains at the forefront of understanding PACAP's role in stress signaling throughout the nervous system.
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27
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Abstract
Stressor exposure is associated with the onset and severity of many psychopathologies that are more common in women than men. Moreover, the maladaptive expression and function of stress-related hormones have been implicated in these disorders. Evidence suggests that PACAP has a critical role in the stress circuits mediating stress-responding, and PACAP may interact with sex hormones to contribute to sex differences in stress-related disease. In this review, we describe the role of the PACAP/PAC1 system in stress biology, focusing on the role of stress-induced alterations in PACAP expression and signaling in the development of stress-induced behavioral change. Additionally, we present more recent data suggesting potential interactions between stress, PACAP, and circulating estradiol in pathological states, including PTSD. These studies suggest that the level of stress and circulating gonadal hormones may differentially regulate the PACAPergic system in males and females to influence anxiety-like behavior and may be one mechanism underlying the discrepancies in human psychiatric disorders.
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Affiliation(s)
- S Bradley King
- a Department of Psychological Science , University of Vermont , Burlington , VT , USA
| | - Donna J Toufexis
- a Department of Psychological Science , University of Vermont , Burlington , VT , USA
| | - Sayamwong E Hammack
- a Department of Psychological Science , University of Vermont , Burlington , VT , USA
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28
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Gap junction communication between chromaffin cells: the hidden face of adrenal stimulus-secretion coupling. Pflugers Arch 2017; 470:89-96. [PMID: 28735418 DOI: 10.1007/s00424-017-2032-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/07/2017] [Accepted: 07/10/2017] [Indexed: 10/19/2022]
Abstract
From birth to death, catecholamine secretion undergoes continuous adjustments, allowing the organism to adapt to homeostasis changes. To cope with these stressful conditions, the neuroendocrine cells of the adrenal medulla play an immediate and crucial role. Chromaffin cell-driven catecholamine release is chiefly controlled by a neurogenic command that arises from the sympathetic nervous system, which releases acetylcholine at the splanchnic nerve terminal-chromaffin cell synapses. In addition to receiving several synaptic inputs individually, chromaffin cells are coupled by gap junctions. This raises interesting questions about the usefulness and the role of the gap junctional coupling within the chromaffin tissue, considering that secretory function is efficiently completed by the neurogenic pathway. The findings that gap junctions contribute to catecholamine secretion, both ex vivo and in vivo, provide some early answers, but their involvement in other cellular functions still remains unexplored. This review summarizes the molecular and physiological evidence that gap junctions can act either as an accelerator or a brake of stimulus-secretion coupling and discusses this functional plasticity in the context of specific needs in circulating catecholamine levels. It introduces the concept of gap junctions as sympathetic activity sensors and guardians of the functional integrity of the chromaffin tissue.
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29
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The Effects of Prior Stress on Anxiety-Like Responding to Intra-BNST Pituitary Adenylate Cyclase Activating Polypeptide in Male and Female Rats. Neuropsychopharmacology 2017; 42:1679-1687. [PMID: 28106040 PMCID: PMC5518896 DOI: 10.1038/npp.2017.16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 01/23/2023]
Abstract
Chronic or repeated exposure to stressful stimuli can result in several maladaptive consequences, including increased anxiety-like behaviors and altered peptide expression in anxiety-related brain structures. Among these structures, the bed nucleus of the stria terminalis (BNST) has been implicated in emotional behaviors as well as regulation of hypothalamic-pituitary-adrenal (HPA) axis activity. In male rodents, chronic variate stress (CVS) has been shown to increase BNST pituitary adenylate cyclase activating polypeptide (PACAP) and its cognate PAC1 receptor transcript, and BNST PACAP signaling may mediate the maladaptive changes associated with chronic stress. Here, we examined whether CVS would sensitize the behavioral and/or endocrine response to a subthreshold BNST PACAP infusion. Male and cycling female rats were exposed to a 7 day CVS paradigm previously shown to upregulate BNST PAC1 receptor transcripts; control rats were not stressed. Twenty-four hours following the last stressor, rats were bilaterally infused into the BNST with a normally subthreshold dose of PACAP. We found an increase in startle amplitude and plasma corticosterone levels 30 min following intra-BNST PACAP infusion in male rats that had been previously exposed to CVS. CVS did not enhance the startle response in cycling females. Equimolar infusion of the VPAC1/2 receptor ligand vasoactive intestinal polypeptide (VIP) had no effect on plasma corticosterone levels even in previously stressed male rats. These results suggest that repeated exposure to stressors may differentially alter the neural circuits underlying the responses to intra-BNST PACAP, and may result in different anxiety-like responses in males and females.
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30
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Wollam J, Mahata S, Riopel M, Hernandez-Carretero A, Biswas A, Bandyopadhyay GK, Chi NW, Eiden LE, Mahapatra NR, Corti A, Webster NJG, Mahata SK. Chromogranin A regulates vesicle storage and mitochondrial dynamics to influence insulin secretion. Cell Tissue Res 2017; 368:487-501. [PMID: 28220294 PMCID: PMC10843982 DOI: 10.1007/s00441-017-2580-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 01/16/2017] [Indexed: 01/01/2023]
Abstract
Chromogranin A (CgA) is a prohormone and a granulogenic factor that regulates secretory pathways in neuroendocrine tissues. In β-cells of the endocrine pancreas, CgA is a major cargo in insulin secretory vesicles. The impact of CgA deficiency on the formation and exocytosis of insulin vesicles is yet to be investigated. In addition, no literature exists on the impact of CgA on mitochondrial function in β-cells. Using three different antibodies, we demonstrate that CgA is processed to vasostatin- and catestatin-containing fragments in pancreatic islet cells. CgA deficiency in Chga-KO islets leads to compensatory overexpression of chromogranin B, secretogranin II, SNARE proteins and insulin genes, as well as increased insulin protein content. Ultrastructural studies of pancreatic islets revealed that Chga-KO β-cells contain fewer immature secretory granules than wild-type (WT) control but increased numbers of mature secretory granules and plasma membrane-docked vesicles. Compared to WT control, CgA-deficient β-cells exhibited increases in mitochondrial volume, numerical densities and fusion, as well as increased expression of nuclear encoded genes (Ndufa9, Ndufs8, Cyc1 and Atp5o). These changes in secretory vesicles and the mitochondria likely contribute to the increased glucose-stimulated insulin secretion observed in Chga-KO mice. We conclude that CgA is an important regulator for coordination of mitochondrial dynamics, secretory vesicular quanta and GSIS for optimal secretory functioning of β-cells, suggesting a strong, CgA-dependent positive link between mitochondrial fusion and GSIS.
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Affiliation(s)
- Joshua Wollam
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Sumana Mahata
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Matthew Riopel
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | | | - Angshuman Biswas
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | | | - Nai-Wen Chi
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, San Diego, CA, USA
| | - Lee E Eiden
- Section on Molecular Neuroscience, NIMH-IRP, Bethesda, MD, USA
| | - Nitish R Mahapatra
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Angelo Corti
- IRCCS San Raffaele Scientific Institute, San Raffaele Vita-Salute University, Milan, Italy
| | - Nicholas J G Webster
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, San Diego, CA, USA
| | - Sushil K Mahata
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
- VA San Diego Healthcare System, San Diego, CA, USA.
- Metabolic Physiology & Ultrastructural Biology Laboratory, Department of Medicine, University of California, San Diego (0732), 9500 Gilman Drive, La Jolla, CA, 92093-0732, USA.
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Brindley RL, Bauer MB, Blakely RD, Currie KP. Serotonin and Serotonin Transporters in the Adrenal Medulla: A Potential Hub for Modulation of the Sympathetic Stress Response. ACS Chem Neurosci 2017; 8:943-954. [PMID: 28406285 PMCID: PMC5541362 DOI: 10.1021/acschemneuro.7b00026] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Serotonin (5-HT) is an important neurotransmitter in the central nervous system where it modulates circuits involved in mood, cognition, movement, arousal, and autonomic function. The 5-HT transporter (SERT; SLC6A4) is a key regulator of 5-HT signaling, and genetic variations in SERT are associated with various disorders including depression, anxiety, and autism. This review focuses on the role of SERT in the sympathetic nervous system. Autonomic/sympathetic dysfunction is evident in patients with depression, anxiety, and other diseases linked to serotonergic signaling. Experimentally, loss of SERT function (SERT knockout mice or chronic pharmacological block) has been reported to augment the sympathetic stress response. Alterations to serotonergic signaling in the CNS and thus central drive to the peripheral sympathetic nervous system are presumed to underlie this augmentation. Although less widely recognized, SERT is robustly expressed in chromaffin cells of the adrenal medulla, the neuroendocrine arm of the sympathetic nervous system. Adrenal chromaffin cells do not synthesize 5-HT but accumulate small amounts by SERT-mediated uptake. Recent evidence demonstrated that 5-HT1A receptors inhibit catecholamine secretion from adrenal chromaffin cells via an atypical mechanism that does not involve modulation of cellular excitability or voltage-gated Ca2+ channels. This raises the possibility that the adrenal medulla is a previously unrecognized peripheral hub for serotonergic control of the sympathetic stress response. As a framework for future investigation, a model is proposed in which stress-evoked adrenal catecholamine secretion is fine-tuned by SERT-modulated autocrine 5-HT signaling.
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Affiliation(s)
- Rebecca L. Brindley
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mary Beth Bauer
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Randy D. Blakely
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, and Florida Atlantic University Brain Institute, Jupiter, FL, USA
| | - Kevin P.M. Currie
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
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Currie KPM. NaV-igating the MAP from PACAP to excitement. Focus on "Activation of MEK/ERK signaling contributes to the PACAP-induced increase in guinea pig cardiac neuron excitability". Am J Physiol Cell Physiol 2016; 311:C641-C642. [PMID: 27653986 DOI: 10.1152/ajpcell.00270.2016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kevin P M Currie
- Department of Anesthesiology and Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
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Mahata SK, Zheng H, Mahata S, Liu X, Patel KP. Effect of heart failure on catecholamine granule morphology and storage in chromaffin cells. J Endocrinol 2016; 230:309-23. [PMID: 27402067 PMCID: PMC4980258 DOI: 10.1530/joe-16-0146] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 06/24/2016] [Indexed: 12/16/2022]
Abstract
One of the key mechanisms involved in sympathoexcitation in chronic heart failure (HF) is the activation of the adrenal glands. Impact of the elevated catecholamines on the hemodynamic parameters has been previously demonstrated. However, studies linking the structural effects of such overactivation with secretory performance and cell metabolism in the adrenomedullary chromaffin cells in vivo have not been previously reported. In this study, HF was induced in male Sprague-Dawley rats by ligation of the left coronary artery. Five weeks after surgery, cardiac function was assessed by ventricular hemodynamics. HF rats showed increased adrenal weight and adrenal catecholamine levels (norepinephrine, epinephrine and dopamine) compared with sham-operated rats. Rats with HF demonstrated increased small synaptic and dense core vesicle in splanchnic-adrenal synapses indicating trans-synaptic activation of catecholamine biosynthetic enzymes, increased endoplasmic reticulum and Golgi lumen width to meet the demand of increased catecholamine synthesis and release, and more mitochondria with dilated cristae and glycogen to accommodate for the increased energy demand for the increased biogenesis and exocytosis of catecholamines from the adrenal medulla. These findings suggest that increased trans-synaptic activation of the chromaffin cells within the adrenal medulla may lead to increased catecholamines in the circulation which in turn contributes to the enhanced neurohumoral drive, providing a unique mechanistic insight for enhanced catecholamine levels in plasma commonly observed in chronic HF condition.
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Affiliation(s)
- Sushil K Mahata
- VA San Diego Healthcare System Metabolic Physiology & Ultrastructural Biology Lab.Department of Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Hong Zheng
- Department of Cellular and Integrative PhysiologyUniversity of Nebraska Medical Center, Omaha, NE, USA
| | - Sumana Mahata
- Caltech Division of BiologyCalifornia Institute of Technology, Pasadena, CA, USA
| | - Xuefei Liu
- Department of Cellular and Integrative PhysiologyUniversity of Nebraska Medical Center, Omaha, NE, USA
| | - Kaushik P Patel
- Department of Cellular and Integrative PhysiologyUniversity of Nebraska Medical Center, Omaha, NE, 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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Mahurkar S, Polytarchou C, Iliopoulos D, Pothoulakis C, Mayer EA, Chang L. Genome-wide DNA methylation profiling of peripheral blood mononuclear cells in irritable bowel syndrome. Neurogastroenterol Motil 2016; 28:410-22. [PMID: 26670691 PMCID: PMC4760882 DOI: 10.1111/nmo.12741] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 10/30/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND Irritable bowel syndrome (IBS) is a stress-sensitive disorder. Environmental factors including stress can trigger epigenetic changes, which have not been well-studied in IBS. We performed a pilot study investigating genome-wide DNA methylation of IBS patients and healthy controls (HCs) to identify potential epigenetic markers and associated pathways. Additionally, we investigated relationships of epigenetic changes in selected genes with clinical traits. METHODS Twenty-seven IBS patients (59% women; 10 IBS-diarrhea, 8 IBS-constipation, 9 IBS-mixed) and 23 age- and sex-matched HCs were examined. DNA methylation from peripheral blood mononuclear cells (PBMCs) was measured using HM450 BeadChip, and representative methylation differences were confirmed by bisulphite sequencing. Gene expression was measured using quantitative PCR. Gastrointestinal (GI) and non-GI symptoms were measured using validated questionnaires. Associations were tested using non-parametric methods. KEY RESULTS Genome-wide DNA methylation profiling of IBS patients compared with HCs identified 133 differentially methylated positions (DMPs) (mean difference ≥10%; p < 0.05). These genes were associated with gene ontology terms including glutathione metabolism related to oxidative stress and neuropeptide hormone activity. Validation by sequencing confirmed differential methylation of subcommissural organ (SCO)-Spondin (SSPO), glutathione-S-transferases mu 5 (GSTM5), and tubulin polymerization promoting protein genes. Methylation of two promoter CpGs in GSTM5 was associated with epigenetic silencing. Epigenetic changes in SSPO gene were positively correlated with hospital anxiety and depression scores in IBS patients (r > 0.4 and false discovery rate <0.05). CONCLUSIONS & INFERENCES This study is the first to comprehensively explore the methylome of IBS patients. We identified DMPs in novel candidate genes which could provide new insights into disease mechanisms; however, these preliminary findings warrant confirmation in larger, independent studies.
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Affiliation(s)
- Swapna Mahurkar
- Oppenheimer Center for Neurobiology of Stress at UCLA; Division of Digestive Diseases, David Geffen School of Medicine at UCLA
| | - Christos Polytarchou
- Center for Systems Biomedicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA
| | - Dimitrios Iliopoulos
- Center for Systems Biomedicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA
| | - Charalabos Pothoulakis
- Department of Medicine, Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA
| | - Emeran A. Mayer
- Oppenheimer Center for Neurobiology of Stress at UCLA; Division of Digestive Diseases, David Geffen School of Medicine at UCLA
| | - Lin Chang
- Oppenheimer Center for Neurobiology of Stress at UCLA; Division of Digestive Diseases, David Geffen School of Medicine at UCLA
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36
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PACAP Modulates Distinct Neuronal Components to Induce Cell-Specific Plasticity at Central and Autonomic Synapses. CURRENT TOPICS IN NEUROTOXICITY 2016. [DOI: 10.1007/978-3-319-35135-3_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Jiang SZ, Eiden LE. PACAPergic Synaptic Signaling and Circuitry Mediating Mammalian Responses to Psychogenic and Systemic Stressors. CURRENT TOPICS IN NEUROTOXICITY 2016. [DOI: 10.1007/978-3-319-35135-3_41] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Tzitzitlini AG, Pedro SC, Martha PAE, Rodolfo DL, Arturo HC. Modulation of spontaneous intracellular Ca²⁺ fluctuations and spontaneous cholinergic transmission in rat chromaffin cells in situ by endogenous GABA acting on GABAA receptors. Pflugers Arch 2015; 468:351-65. [PMID: 26490458 DOI: 10.1007/s00424-015-1744-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/21/2015] [Accepted: 10/04/2015] [Indexed: 12/30/2022]
Abstract
Using fluorescence [Ca(2+)]i imaging in rat adrenal slices, we characterized the effects of agonists and antagonists of the GABAA receptor (GABAA-R) on resting intracellular Ca(2+) ([Ca(2+)]i) and spontaneous [Ca(2+)]i fluctuations (SCFs) in hundreds of individual chromaffin cells (CCs) recorded simultaneously in situ. Muscimol, a GABAA-R agonist (20 μM; 25 s), induced an increase of resting [Ca(2+)]i in 43 ± 3 % of CCs, a decrease in 26 ± 2 %, and no response in 30 ± 5 %. In Ca(2+)-free external medium, SCFs ceased completely and muscimol failed to elicit [Ca(2+)]i rises. All muscimol-induced [Ca(2+)]i changes were blocked by the GABAA-R antagonist bicuculline, suggesting that they result from changes in membrane potential depending on the cell's Cl(-) equilibrium potential. Unexpectedly, bicuculline increased the amplitude and frequency of SCFs in 54 % of CCs, revealing a tonic inhibition of SCFs by ambient GABA acting through GABAA-R. Mecamylamine (a specific nicotinic cholinergic blocker) decreased basal SCF activity in 18 % of CCs and inhibited bicuculline-induced SCF intensification, suggesting that spontaneous acetylcholine (ACh) release from nerve endings contributes to SCF generation in CCs in situ and that blockade of presynaptic GABAA-Rs intensifies SCFs in part through the disinhibition of spontaneous cholinergic transmission. Electrophysiological experiments confirmed that spontaneous excitatory postsynaptic currents recorded from CCs in situ were enhanced by bicuculline. To our knowledge, this is the first description of a regulatory effect of endogenous GABA on synaptic currents and SCFs of adrenal CCs. These findings denote a novel GABA-mediated presynaptic and postsynaptic regulatory mechanism of CC activity which may participate in the control of catecholamine secretion.
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Affiliation(s)
- Alejandre-García Tzitzitlini
- Departamento Neurociencia Cognitiva, Instituto de Fisiología Celular, UNAM. Circuito de la Investigación Científica s/n, Ciudad Universitaria, México, D.F., C.P. 04510, México
| | - Segura-Chama Pedro
- Laboratorio Nacional de Canalopatías from Instituto de Fisiología Celular, México, México
- Unidad de Investigación en Medicina Experimental, México, México
| | - Pérez-Armendáriz E Martha
- Departamento de Biología Celular y Tisular, from Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, D.F., C.P. 04510, Mexico
| | - Delgado-Lezama Rodolfo
- Departamento de Fisiología Biofísica y Neurociencias, from Centro de Investigación y Estudios Avanzados del IPN, Ave. IPN 2508, México City, D.F., México
| | - Hernández-Cruz Arturo
- Departamento Neurociencia Cognitiva, Instituto de Fisiología Celular, UNAM. Circuito de la Investigación Científica s/n, Ciudad Universitaria, México, D.F., C.P. 04510, México.
- Laboratorio Nacional de Canalopatías from Instituto de Fisiología Celular, México, México.
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Podvin S, Bundey R, Toneff T, Ziegler M, Hook V. Profiles of secreted neuropeptides and catecholamines illustrate similarities and differences in response to stimulation by distinct secretagogues. Mol Cell Neurosci 2015; 68:177-85. [PMID: 26092702 DOI: 10.1016/j.mcn.2015.06.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 05/12/2015] [Accepted: 06/01/2015] [Indexed: 12/20/2022] Open
Abstract
The goal of this study was to define profiles of secreted neuropeptide and catecholamine neurotransmitters that undergo co-release from sympathoadrenal chromaffin cells upon stimulation by distinct secretagogues. Chromaffin cells of the adrenal medulla participate in the dynamic responses to stress, especially that of 'fight and flight', and, thus, analyses of the co-release of multiple neurotransmitters is necessary to gain knowledge of how the stress response regulates cell-cell communication among physiological systems. Results of this study demonstrated that six different secretagogues stimulated the co-release of the neuropeptides Met-enkephalin, galanin, NPY, and VIP with the catecholamines dopamine, norepinephrine, and epinephrine. Importantly, the quantitative profiles of the secreted neurotransmitters showed similarities and differences upon stimulation by the different secretagogues evaluated, composed of KCl depolarization, nicotine, carbachol, PACAP, bradykinin, and histamine. The rank-orders of the secreted profiles of the neurotransmitters were generally similar among these secretagogues, but differences in the secreted amounts of each neurotransmitter occurred with different secretagogues. Epinephrine among the catecholamines showed the highest level of secretion. (Met)enkephalin showed the largest levels of secretion compared to the other neuropeptides examined. Levels of secreted catecholamines were greater than that of the neuropeptides. These data support the hypothesis that profiles of secreted neuropeptide and catecholamine neurotransmitters show similarities and differences upon stimulation by distinct secretagogues. These results illustrate the co-release of concerted neurotransmitter profiles that participate in the stress response of the sympathoadrenal nervous system.
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Affiliation(s)
- Sonia Podvin
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Univ. of Calif.-San Diego, La Jolla, CA 92093, United States
| | - Richard Bundey
- Dept. of Medicine, Univ. of Calif.-San Diego, La Jolla, CA 92093, United States
| | - Thomas Toneff
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Univ. of Calif.-San Diego, La Jolla, CA 92093, United States
| | - Michael Ziegler
- Dept. of Medicine, Univ. of Calif.-San Diego, La Jolla, CA 92093, United States
| | - Vivian Hook
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Univ. of Calif.-San Diego, La Jolla, CA 92093, United States; Dept. of Neuroscience and Dept. of Pharmacology, School of Medicine, Univ. of Calif.-San Diego, La Jolla, CA 92093, United States.
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Rubin de Celis MF, Garcia-Martin R, Wittig D, Valencia GD, Enikolopov G, Funk RH, Chavakis T, Bornstein SR, Androutsellis-Theotokis A, Ehrhart-Bornstein M. Multipotent Glia-Like Stem Cells Mediate Stress Adaptation. Stem Cells 2015; 33:2037-51. [DOI: 10.1002/stem.2002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 01/30/2015] [Accepted: 02/06/2015] [Indexed: 01/10/2023]
Affiliation(s)
- Maria F. Rubin de Celis
- Division of Molecular Endocrinology; Medical Clinic III, Carl Gustav Carus University Clinic, Technische Universität Dresden; Dresden Germany
| | - Ruben Garcia-Martin
- Department of Clinical Pathobiochemistry and Institute of Clinical Chemistry and Laboratory Medicine; Carl Gustav Carus University Clinic, Technische Universität Dresden; Dresden Germany
| | - Dierk Wittig
- Institute of Anatomy; Technische Universität Dresden; Dresden Germany
| | - Gabriela D. Valencia
- Division of Molecular Endocrinology; Medical Clinic III, Carl Gustav Carus University Clinic, Technische Universität Dresden; Dresden Germany
| | | | - Richard H. Funk
- Institute of Anatomy; Technische Universität Dresden; Dresden Germany
| | - Triantafyllos Chavakis
- Department of Clinical Pathobiochemistry and Institute of Clinical Chemistry and Laboratory Medicine; Carl Gustav Carus University Clinic, Technische Universität Dresden; Dresden Germany
- Medical Clinic III, Carl Gustav Carus University Clinic, Technische Universität Dresden; Dresden Germany
- Center for Regenerative Therapies Dresden, Technische Universität Dresden; Dresden Germany
| | - Stefan R. Bornstein
- Medical Clinic III, Carl Gustav Carus University Clinic, Technische Universität Dresden; Dresden Germany
- Center for Regenerative Therapies Dresden, Technische Universität Dresden; Dresden Germany
| | - Andreas Androutsellis-Theotokis
- Division of Stem Cell Biology; Medical Clinic III, Carl Gustav Carus University Clinic, Technische Universität Dresden; Dresden Germany
| | - Monika Ehrhart-Bornstein
- Division of Molecular Endocrinology; Medical Clinic III, Carl Gustav Carus University Clinic, Technische Universität Dresden; Dresden Germany
- Center for Regenerative Therapies Dresden, Technische Universität Dresden; Dresden Germany
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PACAP enhances axon outgrowth in cultured hippocampal neurons to a comparable extent as BDNF. PLoS One 2015; 10:e0120526. [PMID: 25807538 PMCID: PMC4373823 DOI: 10.1371/journal.pone.0120526] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Accepted: 01/26/2015] [Indexed: 11/19/2022] Open
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) exerts neurotrophic activities including modulation of synaptic plasticity and memory, hippocampal neurogenesis, and neuroprotection, most of which are shared with brain-derived neurotrophic factor (BDNF). Therefore, the aim of this study was to compare morphological effects of PACAP and BDNF on primary cultured hippocampal neurons. At days in vitro (DIV) 3, PACAP increased neurite length and number to similar levels by BDNF, but vasoactive intestinal polypeptide showed much lower effects. In addition, PACAP increased axon, but not dendrite, length, and soma size at DIV 3 similarly to BDNF. The PACAP antagonist PACAP6–38 completely blocked the PACAP-induced increase in axon, but not dendrite, length. Interestingly, the BDNF-induced increase in axon length was also inhibited by PACAP6–38, suggesting a mechanism involving PACAP signaling. K252a, a TrkB receptor inhibitor, inhibited axon outgrowth induced by PACAP and BDNF without affecting dendrite length. These results indicate that in primary cultured hippocampal neurons, PACAP shows morphological actions via its cognate receptor PAC1, stimulating neurite length and number, and soma size to a comparable extent as BDNF, and that the increase in total neurite length is ascribed to axon outgrowth.
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42
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Winters SJ, King JC, Brees CK, Moore JP. Pituitary adenylate cyclase-activating polypeptide (PACAP) in fetal cord blood. Early Hum Dev 2014; 90:451-3. [PMID: 24995679 DOI: 10.1016/j.earlhumdev.2014.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/29/2014] [Accepted: 06/03/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Pituitary adenylate cyclase-activating peptide (PACAP) is a centrally-acting peptide with highest concentration within the limbic area of the brain. PACAP is also expressed in and affects the functions of vascular and nervous tissues, endocrine glands, and the placenta. PACAP appears to be associated with the 'fight-or-flight' response to emergency partly through its effect on adrenal production of cortisol and catecholamines. OBJECTIVES We sought to explore the impact of labor as a stressor on the level of PACAP in the fetus, and hypothesized that PACAP levels would be increased when labor, abnormal fetal heart tracing, or fetal growth impairment was evident. METHODS Fetal cord venous blood samples were collected immediately after delivery from a random group of women undergoing either vaginal or Cesarean delivery. The blood was placed in chilled EDTA-aprotinin containing tubes, centrifuged, and stored at -80°C for PACAP immunoassay. Delivery data were abstracted for analysis. RESULTS The level of PACAP in cord blood was similar in both males and females. There was a trend toward higher levels in the cord blood of fetuses delivered by Cesarean compared to those delivered vaginally. PACAP levels were unrelated to birth weight, Apgar scores, and the presence or absence of labor prior to delivery. CONCLUSIONS While PACAP and its receptor are expressed in placenta, and PACAP protein is found in cord blood, no effect of labor stress on PACAP was found. Further research is needed to understand the role of PACAP in gestation and parturition.
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Affiliation(s)
| | - Jeffrey C King
- Department of Obstetrics, Gynecology and Women's Health, University of Louisville, United States
| | - Carol K Brees
- Department of Obstetrics, Gynecology and Women's Health, University of Louisville, United States
| | - Joseph P Moore
- Department ofAnatomy and Neurobiology, University of Louisville, United States
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Lezak KR, Roelke E, Harris OM, Choi I, Edwards S, Gick N, Cocchiaro G, Missig G, Roman CW, Braas KM, Toufexis DJ, May V, Hammack SE. Pituitary adenylate cyclase-activating polypeptide (PACAP) in the bed nucleus of the stria terminalis (BNST) increases corticosterone in male and female rats. Psychoneuroendocrinology 2014; 45:11-20. [PMID: 24845172 PMCID: PMC4050443 DOI: 10.1016/j.psyneuen.2014.03.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 03/13/2014] [Accepted: 03/17/2014] [Indexed: 11/17/2022]
Abstract
Single nucleotide polymorphisms (SNP) in the genes for pituitary adenylate cyclase-activating polypeptide (PACAP) and the PAC1 receptor have been associated with several psychiatric disorders whose etiology has been associated with stressor exposure and/or dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. In rats, exposure to repeated variate stress has been shown to increase PACAP and its cognate PAC1 receptor expression in the bed nucleus of the stria terminalis (BNST), a brain region implicated in anxiety and depression-related behaviors as well as the regulation of HPA axis activity. We have argued that changes in BNST PACAP signaling may mediate the changes in emotional behavior and dysregulation of the HPA axis associated with anxiety and mood disorders. The current set of studies was designed to determine whether BNST PACAP infusion leads to activation of the HPA axis as determined by increases in plasma corticosterone. We observed an increase in plasma corticosterone levels 30min following BNST PACAP38 infusion in male and female rats, which was independent of estradiol (E2) treatment in females, and we found that plasma corticosterone levels were increased at both 30min and 60min, but returned to baseline levels 4h following the highest dose. PACAP38 infusion into the lateral ventricles immediately above the BNST did not alter plasma corticosterone level, and the increased plasma corticosterone following BNST PACAP was not blocked by BNST corticotropin releasing hormone (CRH) receptor antagonism. These results support others suggesting that BNST PACAP plays a key role in regulating stress responses.
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Affiliation(s)
- K R Lezak
- Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05405, United States
| | - E Roelke
- Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05405, United States
| | - O M Harris
- Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05405, United States
| | - I Choi
- Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05405, United States; Department of Neurological Sciences, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, United States
| | - S Edwards
- Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05405, United States; Department of Neurological Sciences, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, United States
| | - N Gick
- Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05405, United States; Department of Neurological Sciences, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, United States
| | - G Cocchiaro
- Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05405, United States
| | - G Missig
- Department of Neurological Sciences, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, United States
| | - C W Roman
- Department of Neurological Sciences, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, United States
| | - K M Braas
- Department of Neurological Sciences, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, United States
| | - D J Toufexis
- Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05405, United States
| | - V May
- Department of Neurological Sciences, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, United States
| | - S E Hammack
- Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05405, United States.
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T-type channel-mediated neurotransmitter release. Pflugers Arch 2014; 466:677-87. [PMID: 24595475 DOI: 10.1007/s00424-014-1489-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 02/18/2014] [Indexed: 10/25/2022]
Abstract
Besides controlling a wide variety of cell functions, T-type channels have been shown to regulate neurotransmitter release in peripheral and central synapses and neuroendocrine cells. Growing evidence over the last 10 years suggests a key role of Cav3.2 and Cav3.1 channels in controlling basal neurosecretion near resting conditions and sustained release during mild stimulations. In some cases, the contribution of low-voltage-activated (LVA) channels is not directly evident but requires either the activation of coupled presynaptic receptors, block of ion channels, or chelation of metal ions. Concerning the coupling to the secretory machinery, T-type channels appear loosely coupled to neurotransmitter and hormone release. In neurons, Cav3.2 and Cav3.1 channels mainly control the asynchronous appearance of "minis" [miniature inhibitory postsynaptic currents (mIPSCs) and miniature excitatory postsynaptic currents (mEPSCs)]. The same loose coupling is evident from membrane capacity and amperometric recordings in chromaffin cells and melanotropes where the low-threshold-driven exocytosis possesses the same linear Ca(2+) dependence of the other voltage-gated Ca(2+) channels (Cav1 and Cav2) that is strongly attenuated by slow calcium buffers. The intriguing issue is that, despite not expressing a consensus "synprint" site, Cav3.2 channels do interact with syntaxin 1A and SNAP-25 and, thus, may form nanodomains with secretory vesicles that can be regulated at low voltages. In this review, we discuss all the past and recent issues related to T-type channel-secretion coupling in neurons and neuroendocrine cells.
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Pituitary adenylate cyclase activating polypeptide modulates catecholamine storage and exocytosis in PC12 cells. PLoS One 2014; 9:e91132. [PMID: 24603879 PMCID: PMC3946314 DOI: 10.1371/journal.pone.0091132] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 02/10/2014] [Indexed: 12/19/2022] Open
Abstract
A number of efforts have been made to understand how pituitary adenylate cyclase activating polypeptide (PACAP) functions as a neurotrophic and neuroprotective factor in Parkinson's disease (PD). Recently its effects on neurotransmission and underlying mechanisms have generated interest. In the present study, we investigate the effects of PACAP on catecholamine storage and secretion in PC12 cells with amperometry and transmission electron microscopy (TEM). PACAP increases quantal release induced by high K+ without significantly regulating the frequency of vesicle fusion events. TEM data indicate that the increased volume of the vesicle is mainly the result of enlargement of the fluidic space around the dense core. Moreover, the number of docked vesicles isn't modulated by PACAP. When cells are acutely treated with L-DOPA, the vesicular volume and quantal release both increase dramatically. It is likely that the characteristics of amperometric spikes from L-DOPA treated cells are associated with increased volume of individual vesicles rather than a direct effect on the mechanics of exocytosis. Treatment with PACAP versus L-DOPA results in different profiles of the dynamics of exocytosis. Release via the fusion pore prior to full exocytosis was observed with the same frequency following treatment with PACAP and L-DOPA. However, release events have a shorter duration and higher average current after PACAP treatment compared to L-DOPA. Furthermore, PACAP reduced the proportion of spikes having rapid decay time and shortened the decay time of both fast and slow spikes. In contrast, the distributions of the amperometric spike decay for both fast and slow spikes were shifted to longer time following L-DOPA treatment. Compared to L-DOPA, PACAP may produce multiple favorable effects on dopaminergic neurons, including protecting dopaminergic neurons against neurodegeneration and potentially regulating dopamine storage and release, making it a promising therapeutic agent for the treatment of PD.
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46
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Snapin accelerates exocytosis at low intracellular calcium concentration in mouse chromaffin cells. Cell Calcium 2013; 54:105-10. [DOI: 10.1016/j.ceca.2013.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 04/30/2013] [Accepted: 05/03/2013] [Indexed: 11/20/2022]
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Samal B, Ait-Ali D, Bunn S, Mustafa T, Eiden LE. Discrete signal transduction pathway utilization by a neuropeptide (PACAP) and a cytokine (TNF-alpha) first messenger in chromaffin cells, inferred from coupled transcriptome-promoter analysis of regulated gene cohorts. Peptides 2013; 45:48-60. [PMID: 23608709 PMCID: PMC3807697 DOI: 10.1016/j.peptides.2013.03.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 03/14/2013] [Accepted: 03/14/2013] [Indexed: 12/22/2022]
Abstract
Cultured bovine adrenal chromaffin cells (BCCs) are employed to study first messenger-specific signaling by cytokines and neurotransmitters occurring in the adrenal medulla following immune-related stress responses. Here, we show that the cytokine TNF-alpha, and the neuropeptide transmitter PACAP, acting through the TNFR2 and PAC1 receptors, activate distinct signaling pathways, with correspondingly distinct transcriptomic signatures in chromaffin cells. We have carried out a comprehensive integrated transcriptome analysis of TNF-alpha and PACAP gene regulation in BCCs using two microarray platforms to maximize transcript identification. Microarray data were validated using qRT-PCR. More than 90% of the transcripts up-regulated either by TNF-alpha or PACAP were specific to a single first messenger. The final list of transcripts induced by each first messenger was subjected to multiple algorithms to identify promoter/enhancer response elements for trans-acting factors whose activation could account for gene expression by either TNF-alpha or PACAP. Distinct groups of transcription factors potentially controlling the expression of TNF-alpha or PACAP-responsive genes were found: most of the genes up-regulated by TNF-alpha contained transcription factor binding sites for members of the Rel transcription factor family, suggesting TNF-alpha-TNFR2 signaling occurs mainly through the NF-KB signaling pathway. Surprisingly, EGR1 was predicted to be the primary transcription factor controlling PACAP-modulated genes, suggesting PACAP signaling to the nucleus occurs predominantly through ERK, rather than CREB activation. Comparison of TNFR2-dependent versus TNFR1-dependent gene induction, and EGR1-mediated transcriptional activation, may provide a pharmacological avenue to the unique pathways activated by the first messengers TNF-alpha and PACAP in neuronal and endocrine cells.
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MESH Headings
- Adrenal Glands/cytology
- Adrenal Glands/drug effects
- Adrenal Glands/immunology
- Animals
- Cattle
- Chromaffin Cells/cytology
- Chromaffin Cells/drug effects
- Chromaffin Cells/immunology
- Enhancer Elements, Genetic/drug effects
- Extracellular Signal-Regulated MAP Kinases/genetics
- Extracellular Signal-Regulated MAP Kinases/immunology
- Gene Expression Profiling
- Gene Expression Regulation
- NF-kappa B/genetics
- NF-kappa B/immunology
- Pituitary Adenylate Cyclase-Activating Polypeptide/pharmacology
- Primary Cell Culture
- Promoter Regions, Genetic/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/immunology
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I/genetics
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I/immunology
- Receptors, Tumor Necrosis Factor, Type II/genetics
- Receptors, Tumor Necrosis Factor, Type II/immunology
- Signal Transduction
- Stress, Physiological
- Transcriptome/drug effects
- Transcriptome/immunology
- Tumor Necrosis Factor-alpha/pharmacology
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Affiliation(s)
- Babru Samal
- Section on Molecular Neuroscience, Laboratory of Cellular and
Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892,
USA
| | - Djida Ait-Ali
- Section on Molecular Neuroscience, Laboratory of Cellular and
Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892,
USA
| | - Stephen Bunn
- Centre for Neuroendocrinology, Department of Anatomy, School of
Medical Sciences, University of Otego, PO Box 913, Dunedin, New Zealand
| | - Tomris Mustafa
- Section on Molecular Neuroscience, Laboratory of Cellular and
Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892,
USA
| | - Lee E. Eiden
- Section on Molecular Neuroscience, Laboratory of Cellular and
Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892,
USA
- Corresponding author at: Section on Molecular
Neuroscience, Building 49, Room 5A-38,9000 Rockville Pike, Bethesda, MD 20892,
USA. Tel.: +1 301 496 4110; fax: +1 301 402 1748
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48
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Almli LM, Mercer KB, Kerley K, Feng H, Bradley B, Conneely KN, Ressler KJ. ADCYAP1R1 genotype associates with post-traumatic stress symptoms in highly traumatized African-American females. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:262-72. [PMID: 23505260 PMCID: PMC3738001 DOI: 10.1002/ajmg.b.32145] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 02/13/2013] [Indexed: 01/01/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptor (PAC1) play a critical role in biological processes that mediate stress response and have been implicated in psychological outcome following trauma. Our previous work [Ressler et al. (2011); Nature 470:492-497] demonstrated that a variant, rs2267735, in the gene encoding PAC1 (ADCYAP1R1) is associated with post-traumatic stress disorder (PTSD) in a primarily African-American cohort of highly traumatized females. We sought to extend and replicate our previous finding in a similarly trauma-exposed, replicate sample of 1,160 African-American adult male and female patients. Self-reported psychiatric measures were collected, and DNA was obtained for genetic analysis. Using linear regression models to test for association with PTSD symptom severity under an additive (allelic) model, we found a genotype × trauma interaction in females (P < 0.001), but not males (P > 0.1); however, there was no main effect of genotype as in our previous study. The observed interaction suggests a genetic association that increases with the degree of trauma exposure in females only. This interaction remained significant in females, but not males, after controlling for age (P < 0.001), income (P < 0.01), past substance abuse (P < 0.001), depression severity (P = 0.02), or child abuse (P < 0.0005), and all five combined (P = 0.01). No significant effects of genotype (or interactions) were found when modeling depression severity when controlling for comorbid PTSD symptom severity (P > 0.1), demonstrating the relative specificity of this variant for PTSD symptoms. A meta-analysis with the previously reported African-American samples revealed a strong association between PTSD symptom severity and the interaction between trauma and genotype in females (N = 1424, P < 0.0001).
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Affiliation(s)
- Lynn M. Almli
- Department of Psychiatry and Behavioral Science, Emory University, Atlanta, Georgia
| | - Kristina B. Mercer
- Department of Psychiatry and Behavioral Science, Emory University, Atlanta, Georgia,Howard Hughes Medical Institute, Chevy Chase, Maryland
| | | | - Hao Feng
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, Georgia
| | - Bekh Bradley
- Department of Psychiatry and Behavioral Science, Emory University, Atlanta, Georgia
| | - Karen N. Conneely
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, Georgia,Department of Human Genetics, Emory University, Atlanta, Georgia
| | - Kerry J. Ressler
- Department of Psychiatry and Behavioral Science, Emory University, Atlanta, Georgia,Howard Hughes Medical Institute, Chevy Chase, Maryland,Correspondence to: Kerry J. Ressler, M.D., Ph.D., Department of Psychiatry and Behavioral, Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329.
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49
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Blechman J, Levkowitz G. Alternative Splicing of the Pituitary Adenylate Cyclase-Activating Polypeptide Receptor PAC1: Mechanisms of Fine Tuning of Brain Activity. Front Endocrinol (Lausanne) 2013; 4:55. [PMID: 23734144 PMCID: PMC3659299 DOI: 10.3389/fendo.2013.00055] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Accepted: 04/24/2013] [Indexed: 12/11/2022] Open
Abstract
Alternative splicing of the precursor mRNA encoding for the neuropeptide receptor PAC1/ADCYAP1R1 generates multiple protein products that exhibit pleiotropic activities. Recent studies in mammals and zebrafish have implicated some of these splice isoforms in control of both cellular and body homeostasis. Here, we review the regulation of PAC1 splice variants and their underlying signal transduction and physiological processes in the nervous system.
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Affiliation(s)
- Janna Blechman
- Department of Molecular Cell Biology, Weizmann Institute of ScienceRehovot, Israel
| | - Gil Levkowitz
- Department of Molecular Cell Biology, Weizmann Institute of ScienceRehovot, Israel
- *Correspondence: Gil Levkowitz, Department of Molecular Cell Biology, Weizmann Institute of Science, P. O. Box 26, Rehovot 76100, Israel. e-mail:
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50
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Mustafa T. Pituitary adenylate cyclase-activating polypeptide (PACAP): a master regulator in central and peripheral stress responses. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2013; 68:445-57. [PMID: 24054157 DOI: 10.1016/b978-0-12-411512-5.00021-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is a master regulator of central and peripheral stress responses required to restore and maintain homeostasis. PACAP modulates the hypothalamic-pituitary-adrenal (HPA) axis in response to acute psychogenic but not systemic stressors, through activation of corticotropin-releasing hormone (CRH) release to drive adrenal corticosterone (CORT) output. During direct high-frequency stimulation of the splanchnic nerve that is designed to mimic stress, PACAP regulates adrenomedullary catecholamine secretion. In addition to transmission, PACAP simultaneously facilitates the biosynthesis of adrenomedullary catecholamines through stimulus-secretion-synthesis coupling. During periods of chronic psychogenic stress, PACAP-mediated CORT elevation fails to desensitize and contributes to the development of maladaptive behaviors such as anxiety and depression. Based on these findings, PACAP regulates not only adaptive responses to stress but also maladaptive responses to sustained psychological stress. PACAP receptor antagonists could have therapeutic relevance in preventing hyperactivity of the HPA axis and offering protection against chronic stress-associated anxiety and depression.
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Affiliation(s)
- Tomris Mustafa
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, National Institutes of Mental Health, Bethesda, Maryland, USA.
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