1
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Peña KA, Savransky S, Lewis B. Endosomal signaling via cAMP in parathyroid hormone (PTH) type 1 receptor biology. Mol Cell Endocrinol 2024; 581:112107. [PMID: 37981188 DOI: 10.1016/j.mce.2023.112107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/25/2023] [Accepted: 11/06/2023] [Indexed: 11/21/2023]
Abstract
Compartmentalization of GPCR signaling is an emerging topic that highlights the physiological relevance of spatial bias in signaling. The parathyroid hormone (PTH) type 1 receptor (PTH1R) was the first GPCR described to signal via heterotrimeric G-protein and cAMP from endosomes after β-arrestin mediated internalization, challenging the canonical GPCR signaling model which established that signaling is terminated by receptor internalization. More than a decade later, many other GPCRs have been shown to signal from endosomes via cAMP, and recent studies have proposed that location of cAMP generation impacts physiological outcomes of GPCR signaling. Here, we review the extensive literature regarding PTH1R endosomal signaling via cAMP, the mechanisms that regulate endosomal generation of cAMP, and the implications of spatial bias in PTH1R physiological functions.
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Affiliation(s)
- Karina A Peña
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Sofya Savransky
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Graduate Program in Molecular Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Breanna Lewis
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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2
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Tempone MH, Borges-Martins VP, César F, Alexandrino-Mattos DP, de Figueiredo CS, Raony Í, dos Santos AA, Duarte-Silva AT, Dias MS, Freitas HR, de Araújo EG, Ribeiro-Resende VT, Cossenza M, P. Silva H, P. de Carvalho R, Ventura ALM, Calaza KC, Silveira MS, Kubrusly RCC, de Melo Reis RA. The Healthy and Diseased Retina Seen through Neuron-Glia Interactions. Int J Mol Sci 2024; 25:1120. [PMID: 38256192 PMCID: PMC10817105 DOI: 10.3390/ijms25021120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
The retina is the sensory tissue responsible for the first stages of visual processing, with a conserved anatomy and functional architecture among vertebrates. To date, retinal eye diseases, such as diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa, glaucoma, and others, affect nearly 170 million people worldwide, resulting in vision loss and blindness. To tackle retinal disorders, the developing retina has been explored as a versatile model to study intercellular signaling, as it presents a broad neurochemical repertoire that has been approached in the last decades in terms of signaling and diseases. Retina, dissociated and arranged as typical cultures, as mixed or neuron- and glia-enriched, and/or organized as neurospheres and/or as organoids, are valuable to understand both neuronal and glial compartments, which have contributed to revealing roles and mechanisms between transmitter systems as well as antioxidants, trophic factors, and extracellular matrix proteins. Overall, contributions in understanding neurogenesis, tissue development, differentiation, connectivity, plasticity, and cell death are widely described. A complete access to the genome of several vertebrates, as well as the recent transcriptome at the single cell level at different stages of development, also anticipates future advances in providing cues to target blinding diseases or retinal dysfunctions.
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Affiliation(s)
- Matheus H. Tempone
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Vladimir P. Borges-Martins
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Felipe César
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Dio Pablo Alexandrino-Mattos
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Camila S. de Figueiredo
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Ícaro Raony
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (Í.R.); (H.R.F.)
| | - Aline Araujo dos Santos
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Aline Teixeira Duarte-Silva
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Mariana Santana Dias
- Laboratory of Gene Therapy and Viral Vectors, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.S.D.); (H.P.S.)
| | - Hércules Rezende Freitas
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (Í.R.); (H.R.F.)
| | - Elisabeth G. de Araújo
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
- National Institute of Science and Technology on Neuroimmunomodulation—INCT-NIM, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro 21040-360, Brazil
| | - Victor Tulio Ribeiro-Resende
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Marcelo Cossenza
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Hilda P. Silva
- Laboratory of Gene Therapy and Viral Vectors, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.S.D.); (H.P.S.)
| | - Roberto P. de Carvalho
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Ana L. M. Ventura
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Karin C. Calaza
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Mariana S. Silveira
- Laboratory for Investigation in Neuroregeneration and Development, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil;
| | - Regina C. C. Kubrusly
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Ricardo A. de Melo Reis
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
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3
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Gutierrez Cruz A, Aresta Branco MSL, Borhani Peikani M, Mutafova-Yambolieva VN. Differential Influences of Endogenous and Exogenous Sensory Neuropeptides on the ATP Metabolism by Soluble Ectonucleotidases in the Murine Bladder Lamina Propria. Int J Mol Sci 2023; 24:15650. [PMID: 37958631 PMCID: PMC10647406 DOI: 10.3390/ijms242115650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
Bladder urothelium and suburothelium/lamina propria (LP) have prominent sensory and transducer functions with the active participation of afferent neurons and urothelium-derived purine mediators such as adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), and adenosine (ADO). Effective concentrations of purines at receptor targets depend significantly on the extracellular degradation of ATP by ectonucleotidases (ENTDs). We recently reported the regulated release of soluble ENTDs (s-ENTDs) in the LP and the consequent degradation of ATP to ADP, AMP, and ADO. Afferent neurons in the LP can be activated by urothelial ATP and release peptides and other transmitters that can alter the activity of cells in their vicinity. Using a murine decentralized ex vivo detrusor-free bladder model, 1,N6-etheno-ATP (eATP) as substrate, and sensitive HPLC-FLD methodologies, we found that exogenous neuropeptides calcitonin gene-related peptide (CGRP), substance P (Sub P), neurokinin A (NKA), and pituitary adenylate cyclase-activating polypeptide [PACAP (1-38)] all increased the degradation of eATP by s-ENTDs that were released in the LP spontaneously and/or during bladder filling. Using antagonists of neuropeptide receptors, we observed that endogenous NKA did not modify the ATP hydrolysis by s-ENTDs, whereas endogenous Sub P increased both the constitutive and distention-induced release of s-ENTDs. In contrast, endogenous CGRP and PACAP (1-38) increased the distention-induced, but not the spontaneous, release of s-ENTDs. The present study puts forward the novel idea that interactions between peptidergic and purinergic signaling mechanisms in the LP have an impact on bladder excitability and functions by regulating the effective concentrations of adenine purines at effector cells in the LP.
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Affiliation(s)
| | | | | | - Violeta N. Mutafova-Yambolieva
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV 89557, USA; (A.G.C.); (M.B.P.)
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4
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Langer G, Scott J, Lind C, Otto C, Bothe U, Laux-Biehlmann A, Müller J, le Roy B, Irlbacher H, Nowak-Reppel K, Schlüter A, Davenport AJ, Slack M, Bäurle S. Discovery and In Vitro Characterization of BAY 2686013, an Allosteric Small Molecule Antagonist of the Human Pituitary Adenylate Cyclase-Activating Polypeptide Receptor. Mol Pharmacol 2023; 104:105-114. [PMID: 37348913 DOI: 10.1124/molpharm.122.000662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 05/04/2023] [Accepted: 05/12/2023] [Indexed: 06/24/2023] Open
Abstract
The human pituitary adenylate cyclase-activating polypeptide receptor (hPAC1-R), a class B G-protein-coupled receptor (GPCR) identified almost 30 years ago, represents an important pharmacological target in the areas of neuroscience, oncology, and immunology. Despite interest in this target, only a very limited number of small molecule modulators have been reported for this receptor. We herein describe the results of a drug discovery program aiming for the identification of a potent and selective hPAC1-R antagonist. An initial high-throughput screening (HTS) screen of 3.05 million compounds originating from the Bayer screening library failed to identify any tractable hits. A second, completely revised screen using native human embryonic kidney (HEK)293 cells yielded a small number of hits exhibiting antagonistic properties (4.2 million compounds screened). BAY 2686013 (1) emerged as a promising compound showing selective antagonistic activity in the submicromolar potency range. In-depth characterization supported the hypothesis that BAY 2686013 blocks receptor activity in a noncompetitive manner. Preclinical, pharmacokinetic profiling indicates that BAY 2686013 is a valuable tool compound for better understanding the signaling and function of hPAC1-R. SIGNIFICANCE STATEMENT: Although the human pituitary adenylate cyclase-activating polypeptide receptor (hPAC1-R) is of major significance as a therapeutic target with a well documented role in pain signaling, only a very limited number of small-molecule (SMOL) compounds are known to modulate its activity. We identified and thoroughly characterized a novel, potent, and selective SMOL antagonist of hPAC1-R (acting in an allosteric manner). These characteristics make BAY 2686013 an ideal tool for further studies.
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Affiliation(s)
- Gernot Langer
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - John Scott
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Christoffer Lind
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Christiane Otto
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Ulrich Bothe
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Alexis Laux-Biehlmann
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Jörg Müller
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Beau le Roy
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Horst Irlbacher
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Katrin Nowak-Reppel
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Anne Schlüter
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Adam J Davenport
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Mark Slack
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
| | - Stefan Bäurle
- Bayer AG, Research & Development, Pharmaceuticals, Berlin, Germany (G.L., U.B., J.M., B.l.R., S.B.); Bayer AG, Research & Development, Pharmaceuticals, Wuppertal, Germany (C.O., A.L.-B.); Innovation Campus Berlin, a Nuvisan Company, Berlin, Germany (H.I., K.N.-R.); Evotec SE, Hamburg, Germany (A.S., M.S.); and Evotec (UK) Ltd, Abingdon, Oxfordshire, United Kingdom (J.S., C.L., A.J.D.)
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5
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Alexander TI, Tasma Z, Siow A, Rees TA, Brimble MA, Harris PWR, Hay DL, Walker CS. Novel Fluorescently Labeled PACAP and VIP Highlight Differences between Peptide Internalization and Receptor Pharmacology. ACS Pharmacol Transl Sci 2022; 6:52-64. [PMID: 36654758 PMCID: PMC9841777 DOI: 10.1021/acsptsci.2c00124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Indexed: 12/13/2022]
Abstract
The related peptides pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) have diverse biological functions in peripheral tissues and the central nervous system. Therefore, these peptides and their three receptors represent potential drug targets for several conditions, including neurological and pain-related disorders. However, very little is known about how these peptides regulate their receptors through processes such as internalization. Therefore, we developed tools to study receptor regulation through the synthesis of fluorescently labeled analogues of PACAP-38, PACAP-27, and VIP using copper-mediated 1,3-dipolar cycloaddition of the Cy5 fluorophore. The functionality of Cy5-labeled peptides at their receptors was confirmed in cAMP accumulation assays. Internalization of the Cy5-labeled peptides was then examined and quantified at two distinct PAC1 receptor splice variants, VPAC1 and VPAC2 receptors in transfected cells. All labeled peptides were functional, exhibiting comparable cAMP pharmacology to their unlabeled counterparts and underwent internalization in a time-dependent manner. Temporal differences in the internalization profiles were observed between Cy5-labeled peptides at the PAC1n, PAC1s, VPAC1, and VPAC2 receptors. Interestingly, the pattern of Cy5-labeled peptide activity differed for cAMP accumulation and internalization, indicating that these peptides differentially stimulate cAMP accumulation and internalization and therefore display biased agonism. This novel insight into PACAP-responsive receptor signaling and internalization may provide a unique avenue for future therapeutic development. The fluorescently labeled PACAP and VIP peptides described herein, which we validated as tools to study receptor internalization, will have utility across a broad range of applications and provide greater insight into this receptor family.
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Affiliation(s)
- Tyla I. Alexander
- Department
of Pharmacology and Toxicology, The University
of Otago, Dunedin 9054, New Zealand,Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
| | - Zoe Tasma
- Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand,School
of Biological Sciences, The University of
Auckland, Auckland 1010, New Zealand
| | - Andrew Siow
- School
of Chemical Sciences, The University of
Auckland, Auckland 1010, New Zealand
| | - Tayla A. Rees
- Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand,School
of Biological Sciences, The University of
Auckland, Auckland 1010, New Zealand
| | - Margaret A. Brimble
- Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand,School
of Chemical Sciences, The University of
Auckland, Auckland 1010, New Zealand
| | - Paul W. R. Harris
- Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand,School
of Chemical Sciences, The University of
Auckland, Auckland 1010, New Zealand
| | - Debbie L. Hay
- Department
of Pharmacology and Toxicology, The University
of Otago, Dunedin 9054, New Zealand,Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
| | - Christopher S. Walker
- Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand,School
of Biological Sciences, The University of
Auckland, Auckland 1010, New Zealand,
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6
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Peña KA. Endosomal parathyroid hormone receptor signaling. Am J Physiol Cell Physiol 2022; 323:C783-C790. [PMID: 35912987 PMCID: PMC9467467 DOI: 10.1152/ajpcell.00452.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 11/22/2022]
Abstract
The canonical model for G protein-coupled receptors (GPCRs) activation assumes that stimulation of heterotrimeric G protein signaling upon ligand binding occurs solely at the cell surface and that duration of the stimulation is transient to prevent overstimulation. In this model, GPCR signaling is turned-off by receptor phosphorylation via GPCR kinases (GRKs) and subsequent recruitment of β-arrestins, resulting in receptor internalization into endosomes. Internalized receptors can then recycle back to the cell surface or be trafficked to lysosomes for degradation. However, over the last decade, this model has been extended by discovering that some internalized GPCRs continue to signal via G proteins from endosomes. This is the case for the parathyroid hormone (PTH) type 1 receptor (PTHR), which engages on sustained cAMP signaling from endosomes upon PTH stimulation. Accumulative evidence shows that the location of signaling has an impact on the physiological effects of GPCR signaling. This mini-review discusses recent insights into the mechanisms of PTHR endosomal signaling and its physiological impact.
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Affiliation(s)
- Karina A Peña
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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7
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Lu J, Piper SJ, Zhao P, Miller LJ, Wootten D, Sexton PM. Targeting VIP and PACAP Receptor Signaling: New Insights into Designing Drugs for the PACAP Subfamily of Receptors. Int J Mol Sci 2022; 23:8069. [PMID: 35897648 PMCID: PMC9331257 DOI: 10.3390/ijms23158069] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 12/16/2022] Open
Abstract
Pituitary Adenylate Cyclase-Activating Peptide (PACAP) and Vasoactive Intestinal Peptide (VIP) are neuropeptides involved in a diverse array of physiological and pathological processes through activating the PACAP subfamily of class B1 G protein-coupled receptors (GPCRs): VIP receptor 1 (VPAC1R), VIP receptor 2 (VPAC2R), and PACAP type I receptor (PAC1R). VIP and PACAP share nearly 70% amino acid sequence identity, while their receptors PAC1R, VPAC1R, and VPAC2R share 60% homology in the transmembrane regions of the receptor. PACAP binds with high affinity to all three receptors, while VIP binds with high affinity to VPAC1R and VPAC2R, and has a thousand-fold lower affinity for PAC1R compared to PACAP. Due to the wide distribution of VIP and PACAP receptors in the body, potential therapeutic applications of drugs targeting these receptors, as well as expected undesired side effects, are numerous. Designing selective therapeutics targeting these receptors remains challenging due to their structural similarities. This review discusses recent discoveries on the molecular mechanisms involved in the selectivity and signaling of the PACAP subfamily of receptors, and future considerations for therapeutic targeting.
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Affiliation(s)
- Jessica Lu
- Drug Discovery Biology, Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Sarah J Piper
- Drug Discovery Biology, Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Peishen Zhao
- Drug Discovery Biology, Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Laurence J Miller
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, AZ 85259, USA
| | - Denise Wootten
- Drug Discovery Biology, Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Patrick M Sexton
- Drug Discovery Biology, Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
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8
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McKay K, Hamilton NB, Remington JM, Schneebeli ST, Li J. Essential Dynamics Ensemble Docking for Structure-Based GPCR Drug Discovery. Front Mol Biosci 2022; 9:879212. [PMID: 35847975 PMCID: PMC9277106 DOI: 10.3389/fmolb.2022.879212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/18/2022] [Indexed: 11/23/2022] Open
Abstract
The lack of biologically relevant protein structures can hinder rational design of small molecules to target G protein-coupled receptors (GPCRs). While ensemble docking using multiple models of the protein target is a promising technique for structure-based drug discovery, model clustering and selection still need further investigations to achieve both high accuracy and efficiency. In this work, we have developed an original ensemble docking approach, which identifies the most relevant conformations based on the essential dynamics of the protein pocket. This approach is applied to the study of small-molecule antagonists for the PAC1 receptor, a class B GPCR and a regulator of stress. As few as four representative PAC1 models are selected from simulations of a homology model and then used to screen three million compounds from the ZINC database and 23 experimentally validated compounds for PAC1 targeting. Our essential dynamics ensemble docking (EDED) approach can effectively reduce the number of false negatives in virtual screening and improve the accuracy to seek potent compounds. Given the cost and difficulties to determine membrane protein structures for all the relevant states, our methodology can be useful for future discovery of small molecules to target more other GPCRs, either with or without experimental structures.
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9
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Li J, Remington JM, Liao C, Parsons RL, Schneebeli S, Braas KM, May V, Brewer M. GPCR Intracellular Loop Regulation of Beta-Arrestin-Mediated Endosomal Signaling Dynamics. J Mol Neurosci 2022; 72:1358-1373. [PMID: 35538393 PMCID: PMC9311399 DOI: 10.1007/s12031-022-02016-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 04/22/2022] [Indexed: 12/22/2022]
Abstract
G protein-coupled receptors (GPCRs) are currently appreciated to be routed to diverse cellular platforms to generate both G protein-dependent and -independent signals. The latter has been best studied with respect to β-arrestin-associated receptor internalization and trafficking to signaling endosomes for extracellular signal-regulated kinase (ERK) activation. However, how GPCR structural and conformational variants regulate endosomal ERK signaling dynamics, which can be central in neural development, plasticity, and disease processes, is not well understood. Among class B GPCRs, the PACAP-selective PAC1 receptor is unique in the expression of variants that can contain intracellular loop 3 (ICL3) cassette inserts. The nervous system expresses preferentially the PAC1Null (no insert) and PAC1Hop (28-amino acid Hop insert) receptor variants. Our molecular modeling and signaling studies revealed that the PAC1Null and PAC1Hop receptor variants can associate with β-arrestin differentially, resulting in enhanced receptor internalization and ERK activation for the PAC1Hop variant. The study amplifies our understandings of GPCR intracellular loop structure/function relationships with the first example of how the duration of endosomal ERK activation can be guided by ICL3. The results provide a framework for how changes in GPCR variant expression can impact developmental and homeostatic processes and may be contributory to maladaptive neuroplasticity underlying chronic pain and stress-related disorders.
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Affiliation(s)
- Jianing Li
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA.
| | - Jacob M Remington
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA
| | - Chenyi Liao
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA
| | - Rodney L Parsons
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Avenue, Burlington, VT, 05405, USA
| | - Severin Schneebeli
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA
| | - Karen M Braas
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Avenue, Burlington, VT, 05405, USA
| | - Victor May
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Avenue, Burlington, VT, 05405, USA.
| | - Matthias Brewer
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA
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10
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Maunze B, Bruckner KW, Desai NN, Chen C, Chen F, Baker D, Choi S. Pituitary adenylate cyclase-activating polypeptide receptor activation in the hypothalamus recruits unique signaling pathways involved in energy homeostasis. Am J Physiol Endocrinol Metab 2022; 322:E199-E210. [PMID: 35001657 PMCID: PMC8897015 DOI: 10.1152/ajpendo.00320.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) exerts pleiotropic effects on ventromedial nuclei (VMN) of the hypothalamus and its control of feeding and energy expenditure through the type I PAC1 receptor (PAC1R). However, the endogenous role of PAC1Rs in the VMN and the downstream signaling responsible for PACAP's effects on energy balance are unknown. Numerous studies have revealed that PAC1Rs are coupled to both Gαs/adenylyl cyclase/protein kinase A (Gαs/AC/PKA) and Gαq/phospholipase C/protein kinase C (Gαq/PLC/PKC), while also undergoing trafficking following stimulation. To determine the endogenous role of PAC1Rs and downstream signaling that may explain PACAP's pleiotropic effects, we used RNA interference to knockdown VMN PAC1Rs and pharmacologically inhibited PKA, PKC, and PAC1R trafficking. Knocking down PAC1Rs increased meal sizes, reduced total number of meals, and induced body weight gain. Inhibition of either PKA or PKC alone in awake male Sprague-Dawley rats, attenuated PACAP's hypophagic and anorectic effects during the dark phase. However, PKA or PKC inhibition potentiated PACAP's thermogenic effects during the light phase. Analysis of locomotor activity revealed that PKA inhibition augmented PACAP's locomotor effects, whereas PKC inhibition had no effect. Finally, PACAP administration in the VMN induces surface PAC1R trafficking into the cytosol which was blocked by endocytosis inhibitors. Subsequently, inhibition of PAC1R trafficking into the cytosol attenuated PACAP-induced hypophagia. These results revealed that endogenous PAC1Rs uniquely engage PKA, PKC, and receptor trafficking to mediate PACAP's pleiotropic effects in VMN control of feeding and metabolism.NEW & NOTEWORTHY Endogenous PAC1 receptors, integral to VMN management of feeding behavior and body weight regulation, uniquely engage PKA, PKC, and receptor trafficking to mediate the hypothalamic ventromedial nuclei control of feeding and metabolism. PACAP appears to use different signaling mechanisms to regulate feeding behavior from its effects on metabolism.
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Affiliation(s)
- Brian Maunze
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | | | - Nikhil Nilesh Desai
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Christopher Chen
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Fanghong Chen
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - David Baker
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - SuJean Choi
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
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11
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Tasma Z, Siow A, Harris PWR, Brimble MA, Hay DL, Walker CS. Characterisation of agonist signalling profiles and agonist-dependent antagonism at PACAP-responsive receptors: Implications for drug discovery. Br J Pharmacol 2021; 179:435-453. [PMID: 34612509 DOI: 10.1111/bph.15700] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 08/16/2021] [Accepted: 08/30/2021] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND AND PURPOSE The pituitary adenylate cyclase-activating peptide (PACAP) family is of clinical interest for the treatment of migraine. These peptides activate three different PACAP-responsive class B G protein-coupled receptors: the PAC1 , VPAC1 and VPAC2 receptors. The PAC1 receptor may be alternatively spliced, generating variants that can differ in their pharmacological or signalling profiles. To inform drug discovery efforts targeting migraine, we need to better understand how the different PACAP-responsive receptors signal and how effectively these responses can be blocked by antagonists. EXPERIMENTAL APPROACH The signalling profiles of the human PAC1n , PAC1s , VPAC1 and VPAC2 receptors were examined in transfected Cos7 cells for cAMP, IP1 , pAkt, pERK and pCREB. Biased signalling was then quantified. The ability of antagonists to block PACAP-38, PACAP-27 or VIP stimulated cAMP accumulation at PACAP-responsive receptors was also determined. KEY RESULTS PACAP-responsive receptors exhibited varied pharmacological profiles but activated signalling in a similar manner. The PAC1n and PAC1s receptors displayed distinct pharmacology. At the PAC1s receptor, VIP and PHM were more potent than at the PAC1n receptor. PACAP-responsive receptors displayed agonist-dependent antagonism where PACAP-38 was less effectively antagonised compared to PACAP-27 and VIP. CONCLUSIONS AND IMPLICATIONS The distinct pharmacological profile displayed by the PAC1s receptor suggests that it can act as a dual receptor for VIP and PACAP. Furthermore, the effectiveness of blocking a signalling pathway can be influenced by which endogenous PACAP family agonist is present. These effects have potential implications for the development and effectiveness of drugs targeting the PACAP system.
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Affiliation(s)
- Zoe Tasma
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Andrew Siow
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | - Paul W R Harris
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,School of Chemical Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre and Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Margaret A Brimble
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,School of Chemical Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre and Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Debbie L Hay
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre and Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand.,Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Christopher S Walker
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre and Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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12
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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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13
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May V, Johnson GC, Hammack SE, Braas KM, Parsons RL. PAC1 Receptor Internalization and Endosomal MEK/ERK Activation Is Essential for PACAP-Mediated Neuronal Excitability. J Mol Neurosci 2021; 71:1536-1542. [PMID: 33675454 PMCID: PMC8450765 DOI: 10.1007/s12031-021-01821-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/22/2021] [Indexed: 12/15/2022]
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP, Adcyap1) activation of PAC1 receptors (Adcyap1r1) can significantly increase the excitability of diverse neurons through differential mechanisms. For guinea pig cardiac neurons, the modulation of excitability can be mediated in part by PAC1 receptor plasma membrane G protein-dependent activation of adenylyl cyclase and downstream signaling cascades. By contrast, PAC1 receptor-mediated excitability of hippocampal dentate gyrus granule cells appears independent of membrane-delimited AC/cAMP/PKA and PLC/PKC signaling. For both neuronal types, there is mechanistic convergence demonstrating that endosomal PAC1 receptor signaling has prominent roles. In these models, neuronal exposure to Pitstop2 to inhibit β-arrestin/clathrin-mediated PAC1 receptor internalization eliminates PACAP modulation of excitability. β-arrestin is a scaffold for a number of effectors especially MEK/ERK and notably, paradigms that inhibit PAC1 receptor endosome formation and ERK signaling also blunt the PACAP-induced increase in excitability. Detailed PAC1 receptor internalization and endosomal ERK signaling mechanisms have been confirmed in HEK PAC1R-EGFP cells and shown to be long lasting which appear to recapitulate the sustained electrophysiological responses. Thus, PAC1 receptor internalization/endosomal recruitment efficiently and efficaciously activates MEK/ERK signaling and appears to represent a singular and critical common denominator in regulating neuronal excitability by PACAP.
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Affiliation(s)
- Victor May
- Departmental of Neurological Sciences, University of Vermont College of Medicine, Burlington, VT, USA.
| | - Gregory C Johnson
- Department of Psychological Science, University of Vermont, Burlington, VT, USA
| | - Sayamwong E Hammack
- Department of Psychological Science, University of Vermont, Burlington, VT, USA
| | - Karen M Braas
- Departmental of Neurological Sciences, University of Vermont College of Medicine, Burlington, VT, USA
| | - Rodney L Parsons
- Departmental of Neurological Sciences, University of Vermont College of Medicine, Burlington, VT, USA
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14
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Sutkeviciute I, Vilardaga JP. Structural insights into emergent signaling modes of G protein-coupled receptors. J Biol Chem 2020; 295:11626-11642. [PMID: 32571882 DOI: 10.1074/jbc.rev120.009348] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 06/21/2020] [Indexed: 12/21/2022] Open
Abstract
G protein-coupled receptors (GPCRs) represent the largest family of cell membrane proteins, with >800 GPCRs in humans alone, and recognize highly diverse ligands, ranging from photons to large protein molecules. Very important to human medicine, GPCRs are targeted by about 35% of prescription drugs. GPCRs are characterized by a seven-transmembrane α-helical structure, transmitting extracellular signals into cells to regulate major physiological processes via heterotrimeric G proteins and β-arrestins. Initially viewed as receptors whose signaling via G proteins is delimited to the plasma membrane, it is now recognized that GPCRs signal also at various intracellular locations, and the mechanisms and (patho)physiological relevance of such signaling modes are actively investigated. The propensity of GPCRs to adopt different signaling modes is largely encoded in the structural plasticity of the receptors themselves and of their signaling complexes. Here, we review emerging modes of GPCR signaling via endosomal membranes and the physiological implications of such signaling modes. We further summarize recent structural insights into mechanisms of GPCR activation and signaling. We particularly emphasize the structural mechanisms governing the continued GPCR signaling from endosomes and the structural aspects of the GPCR resensitization mechanism and discuss the recently uncovered and important roles of lipids in these processes.
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Affiliation(s)
- Ieva Sutkeviciute
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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15
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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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16
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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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17
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Splitthoff P, Rasbach E, Neudert P, Bonaterra GA, Schwarz A, Mey L, Schwarzbach H, Eiden LE, Weihe E, Kinscherf R. PAC1 deficiency attenuates progression of atherosclerosis in ApoE deficient mice under cholesterol-enriched diet. Immunobiology 2020; 225:151930. [PMID: 32173151 PMCID: PMC9741700 DOI: 10.1016/j.imbio.2020.151930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 12/14/2022]
Abstract
The neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP) is vasoactive and cytoprotective and exerts immunoregulatory functions throughout the nervous, neuroendocrine cardiovascular and immune systems in health and disease. PACAP mainly acts through PAC1 receptor signaling in neuronal communication, but the role of PAC1 in immune regulation of atherosclerosis is not known. Here, we generated PAC1-/-/ApoE-/- mice to test, whether PAC1-/- influences plasma cholesterol-/triglyceride levels and/or atherogenesis in the brachiocephalic trunk (BT) seen in ApoE-/- mice, under standard chow (SC) or cholesterol-enriched diet (CED). Furthermore, the effect of PAC1-/-, on inflammatory, autophagy-, apoptosis- and necroptosis-relevant proteins in atherosclerotic plaques was determined. In plaques of PAC1-/-/ApoE-/- mice fed a SC, the immunoreactivity for apoptotic, autophagic, necroptotic and proinflammatory proteins was increased, however, proliferation was unaffected. Interestingly, without affecting hyperlipidemia, PAC1-/- in ApoE-/- mice remarkably reduced CED-induced lumen stenosis seen in ApoE-/- mice. Thus, PAC1-/- allows unchecked inflammation, necroptosis and decreased proliferation during SC, apparently priming the BT to develop reduced atheroma under subsequent CED. Remarkably, no differences in inflammation/necroptosis signatures in the atheroma under CED between PAC1-/-/ApoE-/- and ApoE-/- mice were observed. These data indicate that selective PAC1 antagonists should offer potential as a novel class of atheroprotective therapeutics, especially during hypercholesterolemia.
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Affiliation(s)
- Paul Splitthoff
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037, Marburg, Germany
| | - Erik Rasbach
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037, Marburg, Germany
| | - Philip Neudert
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037, Marburg, Germany
| | - Gabriel A. Bonaterra
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037, Marburg, Germany,Corresponding author at: Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35032, Marburg, Germany., (G.A. Bonaterra)
| | - Anja Schwarz
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037, Marburg, Germany
| | - Lilli Mey
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037, Marburg, Germany
| | - Hans Schwarzbach
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037, Marburg, Germany
| | - Lee E. Eiden
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health Intramural Research Program, Bethesda, 20814, Maryland, USA
| | - Eberhard Weihe
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037, Marburg, Germany
| | - Ralf Kinscherf
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037, Marburg, Germany
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Johnson GC, Parsons R, May V, Hammack SE. The Role of Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) Signaling in the Hippocampal Dentate Gyrus. Front Cell Neurosci 2020; 14:111. [PMID: 32425759 PMCID: PMC7203336 DOI: 10.3389/fncel.2020.00111] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 04/08/2020] [Indexed: 01/01/2023] Open
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP, ADCYAP1) dysregulation has been associated with multiple stress-related psychopathologies that may be related to altered hippocampal function. In coherence, PACAP- and PAC1 receptor (ADCYAP1R1)-null mice demonstrate changes in hippocampal-dependent behavioral responses, implicating the PACAPergic system function in this structure. Within the hippocampus, the dentate gyrus (DG) may play an important role in discerning the differences between similar contexts, and DG granule cells appear to both highly express PAC1 receptors and receive inputs from PACAP-expressing terminals. Here, we review the evidence from our laboratories and others that PACAP is an important regulator of activity within hippocampal circuits, particularly within the DG. These data are consistent with an increasing literature implicating PACAP circuits in stress-related pathologies such as post-traumatic stress disorder (PTSD) and implicate the hippocampus, and in particular the DG, as a critical site in which PACAP dysregulation can alter stress-related behaviors.
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Affiliation(s)
- Gregory C Johnson
- Department of Psychological Science, College of Arts and Sciences, University of Vermont, Burlington, VT, United States
| | - Rodney Parsons
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, VT, United States
| | - Victor May
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, VT, United States
| | - Sayamwong E Hammack
- Department of Psychological Science, College of Arts and Sciences, University of Vermont, Burlington, VT, United States
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Johnson GC, Parsons RL, May V, Hammack SE. Pituitary adenylate cyclase-activating polypeptide-induced PAC1 receptor internalization and recruitment of MEK/ERK signaling enhance excitability of dentate gyrus granule cells. Am J Physiol Cell Physiol 2020; 318:C870-C878. [PMID: 32186931 DOI: 10.1152/ajpcell.00065.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP; ADCYAP1) is a pleiotropic neuropeptide widely distributed in both the peripheral and central nervous systems. PACAP and its specific cognate PAC1 receptor (ADCYAP1R1) play critical roles in the homeostatic maintenance of multiple physiological and behavioral systems. Notably, maladaptations in the PACAPergic system have been associated with several psychopathologies related to fear and anxiety. PAC1 receptor transcripts are highly expressed in granule cells of the dentate gyrus (DG). Here, we examined the direct effects of PACAP on DG granule cells in brain slices using whole cell patch recordings in current clamp mode. PACAP significantly increased the intrinsic excitability of DG granule cells via PAC1 receptor activation. This increased excitability was not mediated by adenylyl cyclase/cAMP or phospholipase C/PKC activation, but instead via activation of an extracellular signal-regulated kinase (ERK) signaling pathway initiated through PAC1 receptor endocytosis/endosomal signaling. PACAP failed to increase excitability in DG granule cells pretreated with the persistent sodium current blocker riluzole, suggesting that the observed PACAP effects required this component of the inward sodium current.
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Affiliation(s)
- Gregory C Johnson
- Department of Psychological Science, University of Vermont, Burlington, Vermont
| | - Rodney L Parsons
- Department of Neurological Sciences, University of Vermont, Burlington, Vermont
| | - Victor May
- Department of Neurological Sciences, University of Vermont, Burlington, Vermont
| | - Sayamwong E Hammack
- Department of Psychological Science, University of Vermont, Burlington, Vermont
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20
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Liao C, de Molliens MP, Schneebeli ST, Brewer M, Song G, Chatenet D, Braas KM, May V, Li J. Targeting the PAC1 Receptor for Neurological and Metabolic Disorders. Curr Top Med Chem 2019; 19:1399-1417. [PMID: 31284862 PMCID: PMC6761004 DOI: 10.2174/1568026619666190709092647] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 12/23/2018] [Accepted: 12/26/2018] [Indexed: 12/16/2022]
Abstract
The pituitary adenylate cyclase-activating polypeptide (PACAP)-selective PAC1 receptor (PAC1R, ADCYAP1R1) is a member of the vasoactive intestinal peptide (VIP)/secretin/glucagon family of G protein-coupled receptors (GPCRs). PAC1R has been shown to play crucial roles in the central and peripheral nervous systems. The activation of PAC1R initiates diverse downstream signal transduction pathways, including adenylyl cyclase, phospholipase C, MEK/ERK, and Akt pathways that regulate a number of physiological systems to maintain functional homeostasis. Accordingly, at times of tissue injury or insult, PACAP/PAC1R activation of these pathways can be trophic to blunt or delay apoptotic events and enhance cell survival. Enhancing PAC1R signaling under these conditions has the potential to mitigate cellular damages associated with cerebrovascular trauma (including stroke), neurodegeneration (such as Parkinson's and Alzheimer's disease), or peripheral organ insults. Conversely, maladaptive PACAP/PAC1R signaling has been implicated in a number of disorders, including stressrelated psychopathologies (i.e., depression, posttraumatic stress disorder, and related abnormalities), chronic pain and migraine, and metabolic diseases; abrogating PAC1R signaling under these pathological conditions represent opportunities for therapeutic intervention. Given the diverse PAC1R-mediated biological activities, the receptor has emerged as a relevant pharmaceutical target. In this review, we first describe the current knowledge regarding the molecular structure, dynamics, and function of PAC1R. Then, we discuss the roles of PACAP and PAC1R in the activation of a variety of signaling cascades related to the physiology and diseases of the nervous system. Lastly, we examine current drug design and development of peptides and small molecules targeting PAC1R based on a number of structure- activity relationship studies and key pharmacophore elements. At present, the rational design of PAC1R-selective peptide or small-molecule therapeutics is largely hindered by the lack of structural information regarding PAC1R activation mechanisms, the PACAP-PAC1R interface, and the core segments involved in receptor activation. Understanding the molecular basis governing the PACAP interactions with its different cognate receptors will undoubtedly provide a basis for the development and/or refinement of receptor-selective therapeutics.
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Affiliation(s)
- Chenyi Liao
- Department of Chemistry, University of Vermont, Burlington, VT 05405, United States
| | | | - Severin T Schneebeli
- Department of Chemistry, University of Vermont, Burlington, VT 05405, United States
| | - Matthias Brewer
- Department of Chemistry, University of Vermont, Burlington, VT 05405, United States
| | - Gaojie Song
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - David Chatenet
- INRS - Institut Armand-Frappier, 531 boul. des Prairies, Laval, QC H7V 1B7, Canada
| | - Karen M Braas
- Department of Neurological Sciences, University of Vermont, Larner College of Medicine, 149 Beaumont 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
| | - Jianing Li
- Department of Chemistry, University of Vermont, Burlington, VT 05405, United States
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Richardson CE, Yee C, Shen K. A hormone receptor pathway cell-autonomously delays neuron morphological aging by suppressing endocytosis. PLoS Biol 2019; 17:e3000452. [PMID: 31589601 PMCID: PMC6797217 DOI: 10.1371/journal.pbio.3000452] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 10/17/2019] [Accepted: 09/05/2019] [Indexed: 01/12/2023] Open
Abstract
Neurons have a lifespan that parallels that of the organism and are largely irreplaceable. Their unusually long lifespan predisposes neurons to neurodegenerative disease. We sought to identify physiological mechanisms that delay neuron aging in Caenorhabditis elegans by asking how neuron morphological aging is arrested in the long-lived, alternate organismal state, the dauer diapause. We find that a hormone signaling pathway, the abnormal DAuer Formation (DAF) 12 nuclear hormone receptor (NHR) pathway, functions cell-intrinsically in the dauer diapause to arrest neuron morphological aging, and that same pathway can be cell-autonomously manipulated during normal organismal aging to delay neuron morphological aging. This delayed aging is mediated by suppressing constitutive endocytosis, which alters the subcellular localization of the actin regulator T cell lymphoma Invasion And Metastasis 1 (TIAM-1), thereby decreasing age-dependent neurite growth. Intriguingly, we show that suppressed endocytosis appears to be a general feature of cells in diapause, suggestive that this may be a mechanism to halt the growth and other age-related programs supported by most endosome recycling.
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Affiliation(s)
- Claire E. Richardson
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Callista Yee
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, California, United States of America
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, California, United States of America
- * E-mail:
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Varodayan FP, Minnig MA, Steinman MQ, Oleata CS, Riley MW, Sabino V, Roberto M. PACAP regulation of central amygdala GABAergic synapses is altered by restraint stress. Neuropharmacology 2019; 168:107752. [PMID: 31476352 DOI: 10.1016/j.neuropharm.2019.107752] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 08/27/2019] [Accepted: 08/29/2019] [Indexed: 12/25/2022]
Abstract
The pituitary adenylate cyclase-activating polypeptide (PACAP) system plays a central role in the brain's emotional response to psychological stress by activating cellular processes and circuits associated with threat exposure. The neuropeptide PACAP and its main receptor PAC1 are expressed in the rodent central amygdala (CeA), a brain region critical in negative emotional processing, and CeA PACAPergic signaling drives anxiogenic and stress coping behaviors. Despite this behavioral evidence, PACAP's effects on neuronal activity within the medial subdivision of the CeA (CeM, the major output nucleus for the entire amygdala complex) during basal conditions and after psychological stress remain unknown. Therefore, in the present study, male Wistar rats were subjected to either restraint stress or control conditions, and PACAPergic regulation of CeM cellular function was assessed using immunohistochemistry and whole-cell patch-clamp electrophysiology. Our results demonstrate that PACAP-38 potentiates GABA release in the CeM of naïve rats, via its actions at presynaptic PAC1. Basal PAC1 activity also enhances GABA release in an action potential-dependent manner. Notably, PACAP-38's facilitation of CeM GABA release was attenuated after a single restraint stress session, but after repeated sessions returned to the level observed in naïve animals. A single restraint session also significantly decreased PAC1 levels in the CeM, with repeated restraint sessions producing a slight recovery. Collectively our data reveal that PACAP/PAC1 signaling enhances inhibitory control of the CeM and that psychological stress can modulate this influence to potentially disinhibit downstream effector regions that mediate anxiety and stress-related behaviors. This article is part of the special issue on 'Neuropeptides'.
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Affiliation(s)
- F P Varodayan
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA.
| | - M A Minnig
- Laboratory of Addictive Disorders, Departments of Pharmacology and Psychiatry, Boston University, School of Medicine, Boston, MA, 02118, USA
| | - M Q Steinman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - C S Oleata
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - M W Riley
- Laboratory of Addictive Disorders, Departments of Pharmacology and Psychiatry, Boston University, School of Medicine, Boston, MA, 02118, USA
| | - V Sabino
- Laboratory of Addictive Disorders, Departments of Pharmacology and Psychiatry, Boston University, School of Medicine, Boston, MA, 02118, USA
| | - M Roberto
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA
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Parsons RL, May V. PACAP-Induced PAC1 Receptor Internalization and Recruitment of Endosomal Signaling Regulate Cardiac Neuron Excitability. J Mol Neurosci 2019; 68:340-347. [PMID: 30054797 PMCID: PMC6348136 DOI: 10.1007/s12031-018-1127-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/18/2018] [Indexed: 11/27/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP, Adcyap1) activation of PAC1 receptors (Adcyap1r1) significantly increases excitability of guinea pig cardiac neurons. This modulation of excitability is mediated in part by plasma membrane G protein-dependent activation of adenylyl cyclase and downstream signaling cascades, as well as by endosomal signaling mechanisms. PACAP/PAC1 receptor-mediated activation of plasma membrane adenylyl cyclase (AC) and the resulting increase in cellular cAMP enhances a hyperpolarization-induced nonselective cationic current Ih, which contributes to the PACAP-induced increase in cardiac neuron excitability. Further, PACAP-mediated AC/cAMP/PKA downstream signaling also appears to enhance cardiac neuron IT to facilitate the excitatory responses. PACAP activation of PAC1 receptors rapidly stimulates receptor internalization, and reducing ambient temperature or treatments with the clathrin inhibitor Pitstop2 or the dynamin I/II inhibitor dynasore to block endocytic events can suppress PACAP-enhanced neuronal excitability. Thus, endocytosis inhibitors essentially eliminate PACAP-enhanced excitability suggesting that endosomal platforms represent a primary signaling mechanism. Endosomal signaling is associated canonically with ERK activation and in accord, PACAP-enhanced cardiac neuron excitability is reduced by MEK inhibitor pretreatments. PACAP activation of MEK/ERK signaling can enhance currents through voltage-dependent Nav1.7 channels. Hence, PACAP-induced PAC1 receptor internalization/endosomal signaling, recruitment of MEK/ERK signaling, and modulation of Nav1.7 are implicated as key mechanisms contributing to the PACAP-enhanced neuronal excitability. PACAP/PAC1 receptor-mediated endosomal ERK signaling in central circuits can play key roles in development of chronic pain and anxiety-related responses; thus, PAC1 endosomal signaling likely participates in a variety of homeostatic responses within neuronal circuits in the CNS.
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Affiliation(s)
- Rodney L Parsons
- Departmental of Neurological Sciences, Robert Larner College of Medicine, University of Vermont, Burlington, VT, USA.
| | - Victor May
- Departmental of Neurological Sciences, Robert Larner College of Medicine, University of Vermont, Burlington, VT, USA
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Rasbach E, Splitthoff P, Bonaterra GA, Schwarz A, Mey L, Schwarzbach H, Eiden LE, Weihe E, Kinscherf R. PACAP deficiency aggravates atherosclerosis in ApoE deficient mice. Immunobiology 2018; 224:124-132. [PMID: 30447883 DOI: 10.1016/j.imbio.2018.09.008] [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: 09/26/2018] [Accepted: 09/28/2018] [Indexed: 12/31/2022]
Abstract
Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) plays an important role in cytoprotection, inflammation and cardiovascular regulation. Thus, we studied the involvement of PACAP in atherogenesis. Differentiated human THP-1 macrophages (MΦ) were stimulated with oxidized low-density lipoproteins (oxLDL) and the influence of PACAP38 treatment on lipid content and TNF release was determined. To test the effect of PACAP deficiency (PACAP-/-) on the development of atherosclerosis under standard chow (SC) or cholesterol-enriched diet (CED) in vivo, PACAP-/- mice were crossbred with ApoE-/- to generate PACAP-/-/ApoE-/- mice. Blood cholesterol and triglyceride levels were quantified. Lumen stenosis in the brachiocephalic trunk, cellularity and amounts of pro-inflammatory as well as autophagy-, apoptosis- and necroptosis-relevant proteins were analysed in atherosclerotic plaques by quantitative immunohistochemistry. In vitro, PACAP38 inhibited oxLDL-induced intracellular lipid storage as well as TNF release in MФ. In vivo, after SC, but not under CED, PACAP-/-/ApoE-/- mice showed an increased lumen stenosis compared to ApoE-/- mice. In atherosclerotic plaques of PACAP-/-/ApoE-/- mice, the immunoreactive areas of TNF+, IL-1β+, autophagic, apoptotic and necroptotic cells were increased. In contrast, the overall cell density was decreased compared to ApoE-/- under SC, while no differences were seen under CED. Similar plasma cholesterol levels were observed in PACAP-/-/ApoE-/- and ApoE-/- mice under the respective feeding regime. Thus, PACAP-/-/ApoE-/- mice represent a novel mouse model of accelerated atherosclerosis where CED is not required. Our data indicate that PACAP acts as an endogenous atheroprotective neuropeptide. Thus, stable PACAP agonists may have potential as anti-atherosclerotic therapeutics. The specific PACAP receptor(s) mediating atheroprotection remain(s) to be identified.
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Affiliation(s)
- Erik Rasbach
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037 Marburg, Germany
| | - Paul Splitthoff
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037 Marburg, Germany
| | - Gabriel A Bonaterra
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037 Marburg, Germany.
| | - Anja Schwarz
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037 Marburg, Germany
| | - Lilli Mey
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037 Marburg, Germany
| | - Hans Schwarzbach
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037 Marburg, Germany
| | - Lee E Eiden
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health Intramural Research Program, Bethesda, 20814 MD, USA
| | - Eberhard Weihe
- Department of Molecular and Cellular Neuroscience, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg Robert-Koch-Str. 8, 35037 Marburg, Germany
| | - Ralf Kinscherf
- Department of Medical Cell Biology, Institute for Anatomy and Cell Biology, Medical Faculty, Philipps-University of Marburg, Robert-Koch-Str. 8, 35037 Marburg, Germany
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Ojala J, Tooke K, Hsiang H, Girard BM, May V, Vizzard MA. PACAP/PAC1 Expression and Function in Micturition Pathways. J Mol Neurosci 2018; 68:357-367. [PMID: 30259317 DOI: 10.1007/s12031-018-1170-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 09/13/2018] [Indexed: 12/29/2022]
Abstract
Neural injury, inflammation, or diseases commonly and adversely affect micturition reflex function that is organized by neural circuits in the CNS and PNS. One neuropeptide receptor system, pituitary adenylate cyclase-activating polypeptide (PACAP; Adcyap1), and its cognate receptor, PAC1 (Adcyap1r1), have tissue-specific distributions in the lower urinary tract. PACAP and associated receptors are expressed in the LUT and exhibit changes in expression, distribution, and function in preclinical animal models of bladder pain syndrome (BPS)/interstitial cystitis (IC), a chronic, visceral pain syndrome characterized by pain, and LUT dysfunction. Blockade of the PACAP/PAC1 receptor system reduces voiding frequency and somatic (e.g., hindpaw, pelvic) sensitivity in preclinical animal models and a transgenic mouse model that mirrors some clinical symptoms of BPS/IC. The PACAP/receptor system in micturition pathways may represent a potential target for therapeutic intervention to reduce LUT dysfunction following urinary bladder inflammation.
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Affiliation(s)
- Jacqueline Ojala
- Department of Neurological Sciences, The Robert Larner, M.D. College of Medicine at The University of Vermont, Given Building, D405A, Burlington, VT, 05405, USA
| | - Katharine Tooke
- Department of Neurological Sciences, The Robert Larner, M.D. College of Medicine at The University of Vermont, Given Building, D405A, Burlington, VT, 05405, USA
| | - Harrison Hsiang
- Department of Neurological Sciences, The Robert Larner, M.D. College of Medicine at The University of Vermont, Given Building, D405A, Burlington, VT, 05405, USA
| | - Beatrice M Girard
- Department of Neurological Sciences, The Robert Larner, M.D. College of Medicine at The University of Vermont, Given Building, D405A, Burlington, VT, 05405, USA
| | - Victor May
- Department of Neurological Sciences, The Robert Larner, M.D. College of Medicine at The University of Vermont, Given Building, D405A, Burlington, VT, 05405, USA
| | - Margaret A Vizzard
- Department of Neurological Sciences, The Robert Larner, M.D. College of Medicine at The University of Vermont, Given Building, D405A, Burlington, VT, 05405, USA.
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Thomsen ARB, Jensen DD, Hicks GA, Bunnett NW. Therapeutic Targeting of Endosomal G-Protein-Coupled Receptors. Trends Pharmacol Sci 2018; 39:879-891. [PMID: 30180973 DOI: 10.1016/j.tips.2018.08.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/07/2018] [Accepted: 08/10/2018] [Indexed: 02/08/2023]
Abstract
G-protein-coupled receptors (GPCRs) are conventionally considered to function at the plasma membrane, where they detect extracellular ligands and activate heterotrimeric G proteins that transmit intracellular signals. Consequently, drug discovery efforts have focused on identification of agonists and antagonists of cell surface GPCRs. However, β-arrestin (ARR)-dependent desensitization and endocytosis rapidly terminate G protein signaling at the plasma membrane. Emerging evidence indicates that GPCRs can continue to signal from endosomes by G-protein- and βARR-dependent processes. By regulating the duration and location of intracellular signaling events, GPCRs in endosomes control critically important processes, including gene transcription and ion channel activity. Thus, GPCRs in endosomes, in addition to at the cell surface, have emerged as important therapeutic targets.
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Affiliation(s)
- Alex R B Thomsen
- Departments of Surgery and Pharmacology, Columbia University College of Physicians and Surgeons, Columbia University in the City of New York, 21 Audubon Avenue, Room 209, New York City, NY 10032, USA
| | - Dane D Jensen
- Departments of Surgery and Pharmacology, Columbia University College of Physicians and Surgeons, Columbia University in the City of New York, 21 Audubon Avenue, Room 209, New York City, NY 10032, USA
| | - Gareth A Hicks
- Gastroenterology Drug Discovery Unit (GI DDU), Takeda Pharmaceuticals U.S.A. Inc., 35 Landsdowne Street, Cambridge, MA 02139, USA
| | - Nigel W Bunnett
- Departments of Surgery and Pharmacology, Columbia University College of Physicians and Surgeons, Columbia University in the City of New York, 21 Audubon Avenue, Room 209, New York City, NY 10032, USA.
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29
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Jimenez-Vargas NN, Pattison LA, Zhao P, Lieu T, Latorre R, Jensen DD, Castro J, Aurelio L, Le GT, Flynn B, Herenbrink CK, Yeatman HR, Edgington-Mitchell L, Porter CJH, Halls ML, Canals M, Veldhuis NA, Poole DP, McLean P, Hicks GA, Scheff N, Chen E, Bhattacharya A, Schmidt BL, Brierley SM, Vanner SJ, Bunnett NW. Protease-activated receptor-2 in endosomes signals persistent pain of irritable bowel syndrome. Proc Natl Acad Sci U S A 2018; 115:E7438-E7447. [PMID: 30012612 PMCID: PMC6077730 DOI: 10.1073/pnas.1721891115] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Once activated at the surface of cells, G protein-coupled receptors (GPCRs) redistribute to endosomes, where they can continue to signal. Whether GPCRs in endosomes generate signals that contribute to human disease is unknown. We evaluated endosomal signaling of protease-activated receptor-2 (PAR2), which has been proposed to mediate pain in patients with irritable bowel syndrome (IBS). Trypsin, elastase, and cathepsin S, which are activated in the colonic mucosa of patients with IBS and in experimental animals with colitis, caused persistent PAR2-dependent hyperexcitability of nociceptors, sensitization of colonic afferent neurons to mechanical stimuli, and somatic mechanical allodynia. Inhibitors of clathrin- and dynamin-dependent endocytosis and of mitogen-activated protein kinase kinase-1 prevented trypsin-induced hyperexcitability, sensitization, and allodynia. However, they did not affect elastase- or cathepsin S-induced hyperexcitability, sensitization, or allodynia. Trypsin stimulated endocytosis of PAR2, which signaled from endosomes to activate extracellular signal-regulated kinase. Elastase and cathepsin S did not stimulate endocytosis of PAR2, which signaled from the plasma membrane to activate adenylyl cyclase. Biopsies of colonic mucosa from IBS patients released proteases that induced persistent PAR2-dependent hyperexcitability of nociceptors, and PAR2 association with β-arrestins, which mediate endocytosis. Conjugation to cholestanol promoted delivery and retention of antagonists in endosomes containing PAR2 A cholestanol-conjugated PAR2 antagonist prevented persistent trypsin- and IBS protease-induced hyperexcitability of nociceptors. The results reveal that PAR2 signaling from endosomes underlies the persistent hyperexcitability of nociceptors that mediates chronic pain of IBS. Endosomally targeted PAR2 antagonists are potential therapies for IBS pain. GPCRs in endosomes transmit signals that contribute to human diseases.
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Affiliation(s)
- Nestor N Jimenez-Vargas
- Gastrointestinal Diseases Research Unit, Division of Gastroenterology, Queen's University, Kingston, ON K7L 2V7, Canada
| | - Luke A Pattison
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Peishen Zhao
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - TinaMarie Lieu
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Rocco Latorre
- Department of Surgery, Columbia University College of Physicians and Surgeons, Columbia University, New York, NY 10032
- Department of Pharmacology, Columbia University College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Dane D Jensen
- Department of Surgery, Columbia University College of Physicians and Surgeons, Columbia University, New York, NY 10032
- Department of Pharmacology, Columbia University College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Joel Castro
- Visceral Pain Research Group, Human Physiology, Centre for Neuroscience, Flinders University, Adelaide, SA 5000, Australia
- Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia
| | - Luigi Aurelio
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Giang T Le
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Bernard Flynn
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Carmen Klein Herenbrink
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Holly R Yeatman
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Laura Edgington-Mitchell
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Christopher J H Porter
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Michelle L Halls
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Meritxell Canals
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Nicholas A Veldhuis
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Daniel P Poole
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC 3010, Australia
| | - Peter McLean
- Gastrointestinal Drug Discovery Unit, Takeda Pharmaceuticals, Inc., Cambridge, MA 02139
| | - Gareth A Hicks
- Gastrointestinal Drug Discovery Unit, Takeda Pharmaceuticals, Inc., Cambridge, MA 02139
| | - Nicole Scheff
- Bluestone Center for Clinical Research, New York University College of Dentistry, New York, NY 10010
| | - Elyssa Chen
- Bluestone Center for Clinical Research, New York University College of Dentistry, New York, NY 10010
| | - Aditi Bhattacharya
- Bluestone Center for Clinical Research, New York University College of Dentistry, New York, NY 10010
| | - Brian L Schmidt
- Bluestone Center for Clinical Research, New York University College of Dentistry, New York, NY 10010
| | - Stuart M Brierley
- Visceral Pain Research Group, Human Physiology, Centre for Neuroscience, Flinders University, Adelaide, SA 5000, Australia
- Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia
| | - Stephen J Vanner
- Gastrointestinal Diseases Research Unit, Division of Gastroenterology, Queen's University, Kingston, ON K7L 2V7, Canada
| | - Nigel W Bunnett
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia;
- Department of Surgery, Columbia University College of Physicians and Surgeons, Columbia University, New York, NY 10032
- Department of Pharmacology, Columbia University College of Physicians and Surgeons, Columbia University, New York, NY 10032
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, VIC 3010, Australia
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30
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PACAP38-Mediated Bladder Afferent Nerve Activity Hyperexcitability and Ca 2+ Activity in Urothelial Cells from Mice. J Mol Neurosci 2018; 68:348-356. [PMID: 30022438 DOI: 10.1007/s12031-018-1119-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 07/10/2018] [Indexed: 12/11/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP; Adcyap1) and its cognate PAC1 receptor (Adcyap1r1) have tissue-specific distributions in the lower urinary tract (LUT). The afferent limb of the micturition reflex is often compromised following bladder injury, disease, and inflammatory conditions. We have previously demonstrated that PACAP signaling contributes to increased voiding frequency and decreased bladder capacity with cystitis. Thus, the present studies investigated the sensory components (e.g., urothelial cells, bladder afferent nerves) of the urinary bladder that may underlie the pathophysiology of aberrant PACAP activation. We utilized bladder-pelvic nerve preparations and urothelial sheet preparations to characterize PACAP-induced bladder afferent nerve discharge with distention and PACAP-induced Ca2+ activity, respectively. We determined that PACAP38 (100 nM) significantly (p ≤ 0.01) increased bladder afferent nerve activity with distention that was blocked with a PAC1/VPAC2 receptor antagonist PACAP6-38 (300 nM). PACAP38 (100 nM) also increased Ca2+ activity in urothelial cells over that observed in control preparations. Taken together, these results establish a role for PACAP signaling in bladder sensory components (e.g., urothelial cells, bladder afferent nerves) that may ultimately facilitate increased voiding frequency.
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31
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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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32
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Vollesen ALH, Amin FM, Ashina M. Targeted Pituitary Adenylate Cyclase-Activating Peptide Therapies for Migraine. Neurotherapeutics 2018; 15:371-376. [PMID: 29464574 PMCID: PMC5935633 DOI: 10.1007/s13311-017-0596-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Here, we review the role of pituitary adenylate cyclase-activating peptide-38 (PACAP38) in migraine pathophysiology and data implicating PAC1 receptor as a future drug target in migraine. Much remains to be fully elucidated about migraine pathophysiology, but recent attention has focused on signaling molecule PACAP38, a vasodilator able to induce migraine attacks in patients who experience migraine without aura. PACAP38, with marked and sustained effect, dilates extracerebral arteries but not the middle cerebral artery. The selective affinity of PACAP38 to the PAC1 receptor makes this receptor a highly interesting and potential novel target for migraine treatment. Efficacy of antagonism of this receptor should be investigated in randomized clinical trials.
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Affiliation(s)
- Anne Luise Haulund Vollesen
- Danish Headache Center and Department of Neurology, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2600, Glostrup, Copenhagen, Denmark
| | - Faisal Mohammad Amin
- Danish Headache Center and Department of Neurology, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2600, Glostrup, Copenhagen, Denmark
| | - Messoud Ashina
- Danish Headache Center and Department of Neurology, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2600, Glostrup, Copenhagen, Denmark.
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33
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Girard BM, Tooke K, Vizzard MA. PACAP/Receptor System in Urinary Bladder Dysfunction and Pelvic Pain Following Urinary Bladder Inflammation or Stress. Front Syst Neurosci 2017; 11:90. [PMID: 29255407 PMCID: PMC5722809 DOI: 10.3389/fnsys.2017.00090] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 11/16/2017] [Indexed: 12/11/2022] Open
Abstract
Complex organization of CNS and PNS pathways is necessary for the coordinated and reciprocal functions of the urinary bladder, urethra and urethral sphincters. Injury, inflammation, psychogenic stress or diseases that affect these nerve pathways and target organs can produce lower urinary tract (LUT) dysfunction. Numerous neuropeptide/receptor systems are expressed in the neural pathways of the LUT and non-neural components of the LUT (e.g., urothelium) also express peptides. One such neuropeptide receptor system, pituitary adenylate cyclase-activating polypeptide (PACAP; Adcyap1) and its cognate receptor, PAC1 (Adcyap1r1), have tissue-specific distributions in the LUT. Mice with a genetic deletion of PACAP exhibit bladder dysfunction and altered somatic sensation. PACAP and associated receptors are expressed in the LUT and exhibit neuroplastic changes with neural injury, inflammation, and diseases of the LUT as well as psychogenic stress. Blockade of the PACAP/PAC1 receptor system reduces voiding frequency in preclinical animal models and transgenic mouse models that mirror some clinical symptoms of bladder dysfunction. A change in the balance of the expression and resulting function of the PACAP/receptor system in CNS and PNS bladder reflex pathways may underlie LUT dysfunction including symptoms of urinary urgency, increased voiding frequency, and visceral pain. The PACAP/receptor system in micturition pathways may represent a potential target for therapeutic intervention to reduce LUT dysfunction.
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Affiliation(s)
- Beatrice M Girard
- Department of Neurological Sciences, Larner College of Medicine, The University of Vermont, Burlington, VT, United States
| | - Katharine Tooke
- Department of Neurological Sciences, Larner College of Medicine, The University of Vermont, Burlington, VT, United States
| | - Margaret A Vizzard
- Department of Neurological Sciences, Larner College of Medicine, The University of Vermont, Burlington, VT, United States
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34
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Tompkins JD, Clason TA, Buttolph TR, Girard BM, Linden AK, Hardwick JC, Merriam LA, May V, Parsons RL. Src family kinase inhibitors blunt PACAP-induced PAC1 receptor endocytosis, phosphorylation of ERK, and the increase in cardiac neuron excitability. Am J Physiol Cell Physiol 2017; 314:C233-C241. [PMID: 29141923 DOI: 10.1152/ajpcell.00223.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP, Adcyap1) activation of PAC1 receptors ( Adcyap1r1) significantly increases excitability of guinea pig cardiac neurons. This modulation of excitability is mediated in part by plasma membrane G protein-dependent activation of adenylyl cyclase and downstream signaling cascades. However, additional mechanisms responsible for the enhanced excitability are activated following internalization of the PAC1 receptor and endosomal signaling. Src family kinases play critical roles mediating endocytosis of many trophic factor and G protein-coupled receptors. The present study investigated whether Src family kinases also support the PACAP-induced PAC1 receptor internalization, phosphorylation of ERK, and enhanced neuronal excitability. Using human embryonic kidney cells stably expressing a green fluorescent protein-tagged PAC1 receptor, treatment with the Src family kinase inhibitor PP2 (10 µM) markedly reduced the PACAP-induced PAC1 receptor internalization, and in parallel, both PP2 and Src inhibitor 1 (Src-1, 2 µM) reduced ERK activation determined by Western blot analysis. In contrast, Src family kinase inhibitors did not eliminate a PACAP-induced rise in global calcium generated by inositol (1,4,5)-trisphosphate-induced release of calcium from endoplasmic reticulum stores. From confocal analysis of phosphorylated ERK immunostaining, PP2 treatment significantly attenuated PACAP activation of ERK in neurons within cardiac ganglia whole mount preparations. Intracellular recordings demonstrated that PP2 also significantly blunted a PACAP-induced increase in cardiac neuron excitability. These studies demonstrate Src-related kinase activity in PAC1 receptor internalization, activation of MEK/ERK signaling, and regulation of neuronal excitability. The present results provide further support for the importance of PAC1 receptor endosomal signaling as a key mechanism regulating cellular function.
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Affiliation(s)
- John D Tompkins
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California , Los Angeles, California
| | - Todd A Clason
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont , Burlington, Vermont
| | - Thomas R Buttolph
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont , Burlington, Vermont
| | - Beatrice M Girard
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont , Burlington, Vermont
| | - Anne K Linden
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont , Burlington, Vermont
| | | | - Laura A Merriam
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont , Burlington, Vermont
| | - Victor May
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont , Burlington, Vermont
| | - Rodney L Parsons
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont , Burlington, Vermont
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35
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Yarwood RE, Imlach WL, Lieu T, Veldhuis NA, Jensen DD, Klein Herenbrink C, Aurelio L, Cai Z, Christie MJ, Poole DP, Porter CJH, McLean P, Hicks GA, Geppetti P, Halls ML, Canals M, Bunnett NW. Endosomal signaling of the receptor for calcitonin gene-related peptide mediates pain transmission. Proc Natl Acad Sci U S A 2017; 114:12309-12314. [PMID: 29087309 PMCID: PMC5699040 DOI: 10.1073/pnas.1706656114] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are considered to function primarily at the plasma membrane, where they interact with extracellular ligands and couple to G proteins that transmit intracellular signals. Consequently, therapeutic drugs are designed to target GPCRs at the plasma membrane. Activated GPCRs undergo clathrin-dependent endocytosis. Whether GPCRs in endosomes control pathophysiological processes in vivo and are therapeutic targets remains uncertain. We investigated the contribution of endosomal signaling of the calcitonin receptor-like receptor (CLR) to pain transmission. Calcitonin gene-related peptide (CGRP) stimulated CLR endocytosis and activated protein kinase C (PKC) in the cytosol and extracellular signal regulated kinase (ERK) in the cytosol and nucleus. Inhibitors of clathrin and dynamin prevented CLR endocytosis and activation of cytosolic PKC and nuclear ERK, which derive from endosomal CLR. A cholestanol-conjugated antagonist, CGRP8-37, accumulated in CLR-containing endosomes and selectively inhibited CLR signaling in endosomes. CGRP caused sustained excitation of neurons in slices of rat spinal cord. Inhibitors of dynamin, ERK, and PKC suppressed persistent neuronal excitation. CGRP8-37-cholestanol, but not unconjugated CGRP8-37, prevented sustained neuronal excitation. When injected intrathecally to mice, CGRP8-37-cholestanol inhibited nociceptive responses to intraplantar injection of capsaicin, formalin, or complete Freund's adjuvant more effectively than unconjugated CGRP8-37 Our results show that CLR signals from endosomes to control pain transmission and identify CLR in endosomes as a therapeutic target for pain. Thus, GPCRs function not only at the plasma membrane but also in endosomes to control complex processes in vivo. Endosomal GPCRs are a drug target that deserve further attention.
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Affiliation(s)
- Rebecca E Yarwood
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Wendy L Imlach
- Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia
- Department of Physiology, Monash University, Melbourne, VIC 3800, Australia
| | - TinaMarie Lieu
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Nicholas A Veldhuis
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Dane D Jensen
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Carmen Klein Herenbrink
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Luigi Aurelio
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Zhijian Cai
- Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia
- Department of Physiology, Monash University, Melbourne, VIC 3800, Australia
| | | | - Daniel P Poole
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
- Department of Anatomy and Cell Biology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Christopher J H Porter
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Peter McLean
- Takeda Pharmaceuticals Inc., Cambridge, MA 02139
| | | | - Pierangelo Geppetti
- Department of Health Sciences, Clinical Pharmacology Unit, University of Florence, 50139 Florence, Italy
| | - Michelle L Halls
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Meritxell Canals
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia;
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
| | - Nigel W Bunnett
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia;
- The Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, VIC 3052, Australia
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, VIC 3010, Australia
- Department of Surgery, Columbia University, New York, NY 10032
- Department of Pharmacology, Columbia University, New York, NY 10032
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36
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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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37
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Hardwick JC, Clason TA, Tompkins JD, Girard BM, Baran CN, Merriam LA, May V, Parsons RL. Recruitment of endosomal signaling mediates the forskolin modulation of guinea pig cardiac neuron excitability. Am J Physiol Cell Physiol 2017; 313:C219-C227. [PMID: 28592413 DOI: 10.1152/ajpcell.00094.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 05/31/2017] [Accepted: 06/01/2017] [Indexed: 12/18/2022]
Abstract
Forskolin, a selective activator of adenylyl cyclase (AC), commonly is used to establish actions of G protein-coupled receptors (GPCRs) that are initiated primarily through activation of AC/cAMP signaling pathways. In the present study, forskolin was used to evaluate the potential role of AC/cAMP, which is a major signaling mechanism for the pituitary adenylate cyclase-activating polypeptide (PACAP)-selective PAC1 receptor, in the regulation of guinea pig cardiac neuronal excitability. Forskolin (5-10 µM) increases excitability in ~60% of the cardiac neurons. The forskolin-mediated increase in excitability was considered related to cAMP regulation of a cyclic nucleotide gated channel or via protein kinase A (PKA)/ERK signaling, mechanisms that have been linked to PAC1 receptor activation. However, unlike PACAP mechanisms, forskolin enhancement of excitability was not significantly reduced by treatment with cesium to block currents through hyperpolarization-activated nonselective cation channels (Ih) or by treatment with PD98059 to block MEK/ERK signaling. In contrast, treatment with the clathrin inhibitor Pitstop2 or the dynamin inhibitor dynasore eliminated the forskolin-induced increase in excitability; treatments with the inactive Pitstop analog or PP2 treatment to inhibit Src-mediated endocytosis mechanisms were ineffective. The PKA inhibitor KT5702 significantly suppressed the forskolin-induced change in excitability; further, KT5702 and Pitstop2 reduced the forskolin-stimulated MEK/ERK activation in cardiac neurons. Collectively, the present results suggest that forskolin activation of AC/cAMP/PKA signaling leads to the recruitment of clathrin/dynamin-dependent endosomal transduction cascades, including MEK/ERK signaling, and that endosomal signaling is the critical mechanism underlying the forskolin-induced increase in cardiac neuron excitability.
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Affiliation(s)
| | - Todd A Clason
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont, Burlington, Vermont
| | - John D Tompkins
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, California; and
| | - Beatrice M Girard
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont, Burlington, Vermont
| | - Caitlin N Baran
- Department of Medicine, Robert Larner MD College of Medicine, University of Vermont, Burlington, Vermont
| | - Laura A Merriam
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont, Burlington, Vermont
| | - Victor May
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont, Burlington, Vermont
| | - Rodney L Parsons
- Department of Neurological Sciences, Robert Larner MD College of Medicine, University of Vermont, Burlington, Vermont;
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