1
|
Tasma Z, Rees TA, Guo S, Tan S, O'Carroll SJ, Faull RLM, Curtis MA, Christensen SL, Hay DL, Walker CS. Pharmacology of PACAP and VIP receptors in the spinal cord highlights the importance of the PAC 1 receptor. Br J Pharmacol 2024; 181:2655-2675. [PMID: 38616050 DOI: 10.1111/bph.16376] [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: 12/06/2022] [Revised: 12/18/2023] [Accepted: 01/20/2024] [Indexed: 04/16/2024] Open
Abstract
BACKGROUND AND PURPOSE The spinal cord is a key structure involved in the transmission and modulation of pain. Pituitary adenylate cyclase-activating peptide (PACAP) and vasoactive intestinal peptide (VIP), are expressed in the spinal cord. These peptides activate G protein-coupled receptors (PAC1, VPAC1 and VPAC2) that could provide targets for the development of novel pain treatments. However, it is not clear which of these receptors are expressed within the spinal cord and how these receptors signal. EXPERIMENTAL APPROACH Dissociated rat spinal cord cultures were used to examine agonist and antagonist receptor pharmacology. Signalling profiles were determined for five signalling pathways. The expression of different PACAP and VIP receptors was then investigated in mouse, rat and human spinal cords using immunoblotting and immunofluorescence. KEY RESULTS PACAP, but not VIP, potently stimulated cAMP, IP1 accumulation and ERK and cAMP response element-binding protein (CREB) but not Akt phosphorylation in spinal cord cultures. Signalling was antagonised by M65 and PACAP6-38. PACAP-27 was more effectively antagonised than either PACAP-38 or VIP. The patterns of PAC1 and VPAC2 receptor-like immunoreactivity appeared to be distinct in the spinal cord. CONCLUSIONS AND IMPLICATIONS The pharmacological profile in the spinal cord suggested that a PAC1 receptor is the major functional receptor subtype present and thus likely mediates the nociceptive effects of the PACAP family of peptides in the spinal cord. However, the potential expression of both PAC1 and VPAC2 receptors in the spinal cord highlights that these receptors may play differential roles and are both possible therapeutic targets.
Collapse
MESH Headings
- Animals
- Spinal Cord/metabolism
- Spinal Cord/drug effects
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I/metabolism
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I/agonists
- Humans
- Pituitary Adenylate Cyclase-Activating Polypeptide/pharmacology
- Pituitary Adenylate Cyclase-Activating Polypeptide/metabolism
- Vasoactive Intestinal Peptide/metabolism
- Vasoactive Intestinal Peptide/pharmacology
- Mice
- Rats
- Signal Transduction/drug effects
- Receptors, Vasoactive Intestinal Peptide/metabolism
- Receptors, Vasoactive Intestinal Peptide/antagonists & inhibitors
- Cells, Cultured
- Rats, Sprague-Dawley
- Male
- Mice, Inbred C57BL
- Cyclic AMP/metabolism
- Receptors, Vasoactive Intestinal Peptide, Type II/metabolism
- Receptors, Vasoactive Intestinal Peptide, Type II/agonists
Collapse
Affiliation(s)
- Zoe Tasma
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Tayla A Rees
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Song Guo
- Department of Neurology, Danish Headache Center, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
- Department of Odontology, Panum Institute, Faculty of Health, University of Copenhagen, Copenhagen, Denmark
| | - Sheryl Tan
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, The University of Auckland, Auckland, New Zealand
| | - Simon J O'Carroll
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, The University of Auckland, Auckland, New Zealand
| | - Richard L M Faull
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, The University of Auckland, Auckland, New Zealand
| | - Maurice A Curtis
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, The University of Auckland, Auckland, New Zealand
| | - Sarah L Christensen
- Department of Neurology, Danish Headache Center, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Debbie L Hay
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
- Department of Pharmacology and Toxicology, The University of Otago, Dunedin, New Zealand
| | - Christopher S Walker
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| |
Collapse
|
2
|
Liang L, Chen S, Su W, Zhang H, Yu R. Integrated Transcriptomic and Proteomic Study of the Mechanism of Action of the Novel Small-Molecule Positive Allosteric Modulator 1 in Targeting PAC1-R for the Treatment of D-Gal-Induced Aging Mice. Int J Mol Sci 2024; 25:3872. [PMID: 38612681 PMCID: PMC11011505 DOI: 10.3390/ijms25073872] [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: 02/26/2024] [Revised: 03/29/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024] Open
Abstract
Small-molecule positive allosteric modulator 1 (SPAM1), which targets pituitary adenylate cyclase-activating polypeptide receptor 1 (PAC1-R), has been found to have a neuroprotective effect, and the underlying mechanism was explored in this study. First, using a D-galactose (D-gal)-induced aging mouse model, we confirmed that SPAM1 improves the structure of the hippocampal dentate gyrus and restores the number of neurons. Compared with D-gal model mice, SPAM1-treated mice showed up-regulated expression of Sirtuin 6 (SIRT6) and Lamin B1 and down-regulated expression of YinYang 1 (YY1) and p16. A similar tendency was observed in senescent RGC-5 cells induced by long-term culture, indicating that SPAM1 exhibits significant in vitro and in vivo anti-senescence activity in neurons. Then, using whole-transcriptome sequencing and proteomic analysis, we further explored the mechanism behind SPAM1's neuroprotective effects and found that SPAM is involved in the longevity-regulating pathway. Finally, the up-regulation of neurofilament light and medium polypeptides indicated by the proteomics results was further confirmed by Western blotting. These results help to lay a pharmacological network foundation for the use of SPAM1 as a potent anti-aging therapeutic drug to combat neurodegeneration with anti-senescence, neuroprotective, and nerve regeneration activity.
Collapse
Affiliation(s)
- Lili Liang
- Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Shang Chen
- Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Wanlin Su
- Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Huahua Zhang
- Department of Medical Genetics, Guangdong Medical University, Dongguan 523808, China
| | - Rongjie Yu
- Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
- Guangdong Province Key Laboratory of Bioengineering Medicine, Guangzhou 510632, China
- Guangdong Provincial Biotechnology Drug & Engineering Technology Research Center, Guangzhou 510632, China
- National Engineering Research Center of Genetic Medicine, Guangzhou 510632, China
| |
Collapse
|
3
|
D'Amico AG, Maugeri G, Magrì B, Lombardo C, Saccone S, Federico C, Cavallaro P, Giunta S, Bucolo C, D'Agata V. PACAP-ADNP axis prevents outer retinal barrier breakdown and choroidal neovascularization by interfering with VEGF secreted from retinal pigmented epitelium cells. Peptides 2023; 168:171065. [PMID: 37495040 DOI: 10.1016/j.peptides.2023.171065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/17/2023] [Accepted: 07/23/2023] [Indexed: 07/28/2023]
Abstract
During diabetic retinopathy (DR) progression, the retina undergoes various metabolic changes, including hypoxia-signalling cascade induction in the cells of retinal pigmented epithelium (RPE). The overexpression of hypoxic inducible factors causes transcription of many target genes including vascular endothelial growth factor (VEGF). The RPE cells form the outer blood retinal barrier (oBRB), a specialized structure that regulates ions and metabolites flux into the retina to maintain a suitable quality of its extracellular microenvironment. VEGF worsens retinal condition since its secretion from the basolateral compartment of RPE cells compromises the barrier's integrity and induces choroidal neovascularization. In this work, we hypothesized that PACAP prevents the damage to oBRB and controls choroidal neovascularization through the induction of ADNP. Firstly, we demonstrated that ADNP is expressed in Streptozotocin (STZ)-induced diabetic animals. To validate our hypothesis, we cultured endothelial cells (H5V) forming vessels-like structures, in a conditioned medium (CM) derived from ARPE-19 cells exposed to hyperglycaemic/hypoxic insult, containing a known VEGF concentration. The involvement of PACAP-ADNP axis on oBRB integrity was evaluated through the measurement of trans-epithelial-electrical resistance and permeability assay performed on ARPE cell monolayer cultured in CM and by analysing the expression of two tight junction forming proteins, ZO1 and occludin. By culturing H5V in CM, we demonstrated that PACAP-ADNP axis counteracted vessels-like structures formation promoted by VEGF. In conclusion, the results suggested a primary role of PACAP/ADNP axis in preventing oBRB damage and in controlling aberrant choroidal neovascularization induced by VEGF secreted from RPE cells exposed to hyperglycaemia/hypoxic insult in DR.
Collapse
Affiliation(s)
- Agata Grazia D'Amico
- Department of Drug and Health Sciences, Section of System Biology, University of Catania, 95125 Catania, Italy
| | - Grazia Maugeri
- Department of Biomedical and Biotechnological Sciences, Section of Anatomy, Histology and Movement Sciences, University of Catania, 95100 Catania, Italy
| | - Benedetta Magrì
- Department of Biomedical and Biotechnological Sciences, Section of Anatomy, Histology and Movement Sciences, University of Catania, 95100 Catania, Italy
| | - Claudia Lombardo
- Department of Biomedical and Biotechnological Sciences, Section of Anatomy, Histology and Movement Sciences, University of Catania, 95100 Catania, Italy
| | - Salvatore Saccone
- Department of Biological, Geological and Environmental Sciences, Section of Animal Biology, University of Catania, 95123 Catania, Italy
| | - Concetta Federico
- Department of Biological, Geological and Environmental Sciences, Section of Animal Biology, University of Catania, 95123 Catania, Italy
| | - Paola Cavallaro
- Pediatric Unit, Department of Human Pathology in Adult and Developmental Age "Gaetano Barresi", University of Messina, Italy
| | - Salvatore Giunta
- Department of Biomedical and Biotechnological Sciences, Section of Anatomy, Histology and Movement Sciences, University of Catania, 95100 Catania, Italy
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy; Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
| | - Velia D'Agata
- Department of Biomedical and Biotechnological Sciences, Section of Anatomy, Histology and Movement Sciences, University of Catania, 95100 Catania, Italy; Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy.
| |
Collapse
|
4
|
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.
Collapse
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.)
| |
Collapse
|
5
|
Fan G, Chen S, Liang L, Zhang H, Yu R. Novel Small Molecule Positive Allosteric Modulator SPAM1 Triggers the Nuclear Translocation of PAC1-R to Exert Neuroprotective Effects through Neuron-Restrictive Silencer Factor. Int J Mol Sci 2022; 23:ijms232415996. [PMID: 36555637 PMCID: PMC9784932 DOI: 10.3390/ijms232415996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/09/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022] Open
Abstract
The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) exerts effective neuroprotective activity through its specific receptor, PAC1-R. We accidentally discovered that as a positive allosteric modulator (PAM) of PAC1-R, the small-molecule PAM (SPAM1) has a hydrazide-like structure, but different binding characteristics, from hydrazide for the N-terminal extracellular domain of PAC1-R (PAC1-R-EC1). SPAM1 had a significant neuroprotective effect against oxidative stress, both in a cell model treated with hydrogen peroxide (H2O2) and an aging mouse model induced by D-galactose (D-gal). SPAM1 was found to block the decrease in PACAP levels in brain tissues induced by D-gal and significantly induced the nuclear translocation of PAC1-R in PAC1R-CHO cells and mouse retinal ganglion cells. Nuclear PAC1-R was subjected to fragmentation and the nuclear 35 kDa, but not the 15 kDa fragments, of PAC1-R interacted with SP1 to upregulate the expression of Huntingtin (Htt), which then exerted a neuroprotective effect by attenuating the binding availability of the neuron-restrictive silencer factor (NRSF) to the neuron-restrictive silencer element (NRSE). This resulted in an upregulation of the expression of NRSF-related neuropeptides, including PACAP, the brain-derived neurotrophic factor (BDNF), tyrosine hydroxylase (TH), and synapsin-1 (SYN1). The novel mechanism reported in this study indicates that SPAM1 has potential use as a drug, as it exerts a neuroprotective effect by regulating NRSF.
Collapse
Affiliation(s)
- Guangchun Fan
- Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Shang Chen
- Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Lili Liang
- Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Huahua Zhang
- Department of Medical Genetics, Guangdong Medical University, Dongguan 523808, China
| | - Rongjie Yu
- Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
- Guangdong Province Key Laboratory of Bioengineering Medicine, Guangzhou 510632, China
- Guangdong Provincial Biotechnology Drug & Engineering Technology Research Center, Guangzhou 510632, China
- National Engineering Research Center of Genetic Medicine, Guangzhou 510632, China
- Correspondence: or ; Tel.: +86-133-9262-5921
| |
Collapse
|
6
|
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.
Collapse
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,
| |
Collapse
|
7
|
Piper SJ, Deganutti G, Lu J, Zhao P, Liang YL, Lu Y, Fletcher MM, Hossain MA, Christopoulos A, Reynolds CA, Danev R, Sexton PM, Wootten D. Understanding VPAC receptor family peptide binding and selectivity. Nat Commun 2022; 13:7013. [PMID: 36385145 PMCID: PMC9668914 DOI: 10.1038/s41467-022-34629-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 11/01/2022] [Indexed: 11/18/2022] Open
Abstract
The vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) receptors are key regulators of neurological processes. Despite recent structural data, a comprehensive understanding of peptide binding and selectivity among different subfamily receptors is lacking. Here, we determine structures of active, Gs-coupled, VIP-VPAC1R, PACAP27-VPAC1R, and PACAP27-PAC1R complexes. Cryo-EM structural analyses and molecular dynamics simulations (MDSs) reveal fewer stable interactions between VPAC1R and VIP than for PACAP27, more extensive dynamics of VIP interaction with extracellular loop 3, and receptor-dependent differences in interactions of conserved N-terminal peptide residues with the receptor core. MD of VIP modelled into PAC1R predicts more transient VIP-PAC1R interactions in the receptor core, compared to VIP-VPAC1R, which may underlie the selectivity of VIP for VPAC1R over PAC1R. Collectively, our work improves molecular understanding of peptide engagement with the PAC1R and VPAC1R that may benefit the development of novel selective agonists.
Collapse
Affiliation(s)
- Sarah J. Piper
- grid.1002.30000 0004 1936 7857Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia ,grid.1002.30000 0004 1936 7857ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia
| | - Giuseppe Deganutti
- grid.8096.70000000106754565Centre for Sport, Exercise and Life Sciences, Coventry University, CV1 5FB Coventry, UK
| | - Jessica Lu
- grid.1002.30000 0004 1936 7857Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia ,grid.1002.30000 0004 1936 7857ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia
| | - Peishen Zhao
- grid.1002.30000 0004 1936 7857Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia ,grid.1002.30000 0004 1936 7857ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia
| | - Yi-Lynn Liang
- grid.1002.30000 0004 1936 7857Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia ,Present Address: Confo TherapeuticsTechnologiepark 94, Ghent (Zwijnaarde), 9052 Belgium
| | - Yao Lu
- grid.1002.30000 0004 1936 7857Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia ,grid.1002.30000 0004 1936 7857ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia
| | - Madeleine M. Fletcher
- grid.1002.30000 0004 1936 7857Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia ,grid.454018.c0000 0004 0632 8971Present Address: GlaxoSmithKline, Abbotsford, 3067 VIC Australia
| | - Mohammed Akhter Hossain
- grid.1008.90000 0001 2179 088XFlorey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3010 Australia
| | - Arthur Christopoulos
- grid.1002.30000 0004 1936 7857Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia ,grid.1002.30000 0004 1936 7857ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia
| | - Christopher A. Reynolds
- grid.8096.70000000106754565Centre for Sport, Exercise and Life Sciences, Coventry University, CV1 5FB Coventry, UK ,grid.8356.80000 0001 0942 6946School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ UK
| | - Radostin Danev
- grid.26999.3d0000 0001 2151 536XGraduate School of Medicine, University of Tokyo, S402, 7-3-1 Hongo, Bunkyo-ku, 113-0033 Tokyo, Japan
| | - Patrick M. Sexton
- grid.1002.30000 0004 1936 7857Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia ,grid.1002.30000 0004 1936 7857ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia
| | - Denise Wootten
- grid.1002.30000 0004 1936 7857Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia ,grid.1002.30000 0004 1936 7857ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 VIC Australia
| |
Collapse
|
8
|
Tasma Z, Siow A, Harris PWR, Brimble MA, O’Carroll SJ, Hay DL, Walker CS. PAC 1, VPAC 1, and VPAC 2 Receptor Expression in Rat and Human Trigeminal Ganglia: Characterization of PACAP-Responsive Receptor Antibodies. Int J Mol Sci 2022; 23:ijms232213797. [PMID: 36430275 PMCID: PMC9697343 DOI: 10.3390/ijms232213797] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/02/2022] [Accepted: 11/06/2022] [Indexed: 11/11/2022] Open
Abstract
Pituitary adenylate cyclase-activating peptide (PACAP) is a neuropeptide expressed in the trigeminal ganglia (TG). The TG conducts nociceptive signals in the head and may play roles in migraine. PACAP infusion provokes headaches in healthy individuals and migraine-like attacks in patients; however, it is not clear whether targeting this system could be therapeutically efficacious. To effectively target the PACAP system, an understanding of PACAP receptor distribution is required. Therefore, this study aimed to characterize commercially available antibodies and use these to detect PACAP-responsive receptors in the TG. Antibodies were initially validated in receptor transfected cell models and then used to explore receptor expression in rat and human TG. Antibodies were identified that could detect PACAP-responsive receptors, including the first antibody to differentiate between the PAC1n and PAC1s receptor splice variants. PAC1, VPAC1, and VPAC2 receptor-like immunoreactivity were observed in subpopulations of both neuronal and glial-like cells in the TG. In this study, PAC1, VPAC1, and VPAC2 receptors were detected in the TG, suggesting they are all potential targets to treat migraine. These antibodies may be useful tools to help elucidate PACAP-responsive receptor expression in tissues. However, most antibodies exhibited limitations, requiring the use of multiple methodologies and the careful inclusion of controls.
Collapse
Affiliation(s)
- Zoe Tasma
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
| | - Andrew Siow
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
| | - Paul W. R. Harris
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
| | - Margaret A. Brimble
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
| | - Simon J. O’Carroll
- Department of Anatomy and Medical Imaging, and Centre for Brain Research, Faculty of Medical and Health Science, The University of Auckland, Auckland 1023, New Zealand
| | - Debbie L. Hay
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
- Department of Pharmacology and Toxicology, The University of Otago, Dunedin 9016, New Zealand
| | - Christopher S. Walker
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
- Correspondence:
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Positive allosteric regulation of PAC1-R up-regulates PAC1-R and its specific ligand PACAP. Acta Biochim Biophys Sin (Shanghai) 2022; 54:657-672. [PMID: 35593471 PMCID: PMC9828401 DOI: 10.3724/abbs.2022041] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
PAC1-R is a recognized preferential receptor for the neuropeptide of pituitary adenylate cyclase-activating polypeptide (PACAP), which mediates neuroprotective and nerve regenerative activities of PACAP. In this study, we found that in both PAC1R-CHO cells with high expression of PAC1R-eGFP and retinal ganglion cells (RGC-5) with the natural expression of PAC1-R, oligo-peptide PACAP(28-38) and the positively charged arginine-rich penetrating peptide TAT, as positive allosteric modulators of PAC1-R, significantly trigger the nuclear translocation of PAC1-R. The chromatin immunoprecipitation (ChIP)-PCR results show that the nuclear translocated PAC1-R binds with the promoter regions of PAC1-R and its specific ligand PACAP. The up-regulated promoter activities of PAC1-R and PACAP induced by PACAP(28-38) or TAT are positively correlative with the increase of the expression levels of PAC1-R and PACAP. Moreover, the nuclear translocation of PAC1-R induced by PACAP(28-38) or TAT is significantly inhibited by the mutation of PAC1-R on Cys25 and the palmitoylation inhibitor 2-bromopalmitate. Meanwhile, the increase in both PAC1-R and PACAP levels and the neuroprotective activities of PACAP(28-38) and TAT in MPP-induced cell model of Parkinson ' s disease are synchronously inhibited by 2-bromopalmitate, which are positively correlated with the nuclear translocation of PAC1-R induced by PACAP(28-38) or TAT. Bioinformatics analysis and motif enrichment analysis following ChIP-sequencing show that the transcription factors including SP1, Zic2, GATA1, REST and YY1 may be recruited by nuclear PAC1-R and involved in regulating the promoter activities of PAC1-R and PACAP. ChIP-sequencing and related bioinformatics analysis show that the downstream target genes regulated by the nuclear PAC1-R are mostly involved in the process of cellular stress and related to neuroprotection, neuronal genesis and development.
Collapse
|
11
|
Langer I, Jeandriens J, Couvineau A, Sanmukh S, Latek D. Signal Transduction by VIP and PACAP Receptors. Biomedicines 2022; 10:biomedicines10020406. [PMID: 35203615 PMCID: PMC8962308 DOI: 10.3390/biomedicines10020406] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 02/05/2023] Open
Abstract
Homeostasis of the human immune system is regulated by many cellular components, including two neuropeptides, VIP and PACAP, primary stimuli for three class B G protein-coupled receptors, VPAC1, VPAC2, and PAC1. Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) regulate intestinal motility and secretion and influence the functioning of the endocrine and immune systems. Inhibition of VIP and PACAP receptors is an emerging concept for new pharmacotherapies for chronic inflammation and cancer, while activation of their receptors provides neuroprotection. A small number of known active compounds for these receptors still impose limitations on their use in therapeutics. Recent cryo-EM structures of VPAC1 and PAC1 receptors in their agonist-bound active state have provided insights regarding their mechanism of activation. Here, we describe major molecular switches of VPAC1, VPAC2, and PAC1 that may act as triggers for receptor activation and compare them with similar non-covalent interactions changing upon activation that were observed for other GPCRs. Interhelical interactions in VIP and PACAP receptors that are important for agonist binding and/or activation provide a molecular basis for the design of novel selective drugs demonstrating anti-inflammatory, anti-cancer, and neuroprotective effects. The impact of genetic variants of VIP, PACAP, and their receptors on signalling mediated by endogenous agonists is also described. This sequence diversity resulting from gene splicing has a significant impact on agonist selectivity and potency as well as on the signalling properties of VIP and PACAP receptors.
Collapse
Affiliation(s)
- Ingrid Langer
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université libre de Bruxelles, B-1070 Brussels, Belgium; (I.L.); (J.J.)
| | - Jérôme Jeandriens
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM), Université libre de Bruxelles, B-1070 Brussels, Belgium; (I.L.); (J.J.)
| | - Alain Couvineau
- UMR 1149 Inserm, Centre de Recherche sur l’Inflammation (CRI), Université de Paris, 75018 Paris, France;
| | - Swapnil Sanmukh
- Faculty of Chemistry, University of Warsaw, 02-093 Warsaw, Poland;
| | - Dorota Latek
- Faculty of Chemistry, University of Warsaw, 02-093 Warsaw, Poland;
- Correspondence:
| |
Collapse
|
12
|
Cong Z, Liang YL, Zhou Q, Darbalaei S, Zhao F, Feng W, Zhao L, Xu HE, Yang D, Wang MW. Structural perspective of class B1 GPCR signaling. Trends Pharmacol Sci 2022; 43:321-334. [DOI: 10.1016/j.tips.2022.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/01/2022] [Accepted: 01/03/2022] [Indexed: 12/12/2022]
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Liao C, Remington JM, May V, Li J. Molecular Basis of Class B GPCR Selectivity for the Neuropeptides PACAP and VIP. Front Mol Biosci 2021; 8:644644. [PMID: 33842547 PMCID: PMC8027070 DOI: 10.3389/fmolb.2021.644644] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/16/2021] [Indexed: 11/13/2022] Open
Abstract
The related neuropeptides PACAP and VIP, and their shared PAC1, VPAC1 and VPAC2 receptors, regulate a large array of physiological activities in the central and peripheral nervous systems. However, the lack of comparative and molecular mechanistic investigations hinder further understanding of their preferred binding selectivity and function. PACAP and VIP have comparable affinity at the VPAC1 and VPAC2 receptor, but PACAP is 400-1,000 fold more potent than VIP at the PAC1 receptor. A molecular understanding of the differing neuropeptide-receptor interactions and the details underlying the receptor transitions leading to receptor activation are much needed for the rational design of selective ligands. To these ends, we have combined structural information and advanced simulation techniques to study PACAP/VIP binding selectivity, full-length receptor conformation ensembles and transitions of the PACAP/VIP receptor variants and subtypes, and a few key interactions in the orthosteric-binding pocket. Our results reveal differential peptide-receptor interactions (at the atomistic detail) important for PAC1, VPAC1 and VPAC2 receptor ligand selectivity. Using microsecond-long molecular dynamics simulations and the Markov State Models, we have also identified diverse receptor conformational ensembles and microstate transition paths for each receptor, the potential mechanisms underlying receptor open and closed states, and the interactions and dynamics at the transmembrane orthosteric pocket for receptor activation. These analyses reveal important features in class B GPCR structure-dynamics-function relationships, which provide novel insights for structure-based drug discovery.
Collapse
Affiliation(s)
- Chenyi Liao
- Department of Chemistry, University of Vermont, Burlington, VT, United States.,State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Dalian, China
| | - Jacob M Remington
- Department of Chemistry, University of Vermont, Burlington, VT, United States
| | - Victor May
- Department of Neuroscience, University of Vermont, Burlington, VT, United States
| | - Jianing Li
- Department of Chemistry, University of Vermont, Burlington, VT, United States
| |
Collapse
|
15
|
Ruel J, Guitton MJ, Gratias P, Lenoir M, Shen S, Puel JL, Brabet P, Wang J. Endogenous Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) Plays a Protective Effect Against Noise-Induced Hearing Loss. Front Cell Neurosci 2021; 15:658990. [PMID: 33828461 PMCID: PMC8019930 DOI: 10.3389/fncel.2021.658990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/02/2021] [Indexed: 01/07/2023] Open
Abstract
Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a member of the vasoactive intestinal polypeptide (VIP)-the secretin-glucagon family of neuropeptides. They act through two classes of receptors: PACAP type 1 (PAC1) and type 2 (VPAC1 and VPAC2). Among their pleiotropic effects throughout the body, PACAP functions as neuromodulators and neuroprotectors, rescuing neurons from apoptosis, mostly through the PAC1 receptor. To explore the potential protective effect of endogenous PACAP against Noise-induced hearing loss (NIHL), we used a knockout mouse model lacking PAC1 receptor expression (PACR1−/−) and a transgenic humanized mouse model expressing the human PAC1 receptor (TgHPAC1R). Based on complementary approaches combining electrophysiological, histochemical, and molecular biological evaluations, we show PAC1R expression in spiral ganglion neurons and in cochlear apical cells of the organ of Corti. Wild-type (WT), PAC1R−/−, and TgHPAC1R mice exhibit similar auditory thresholds. For most of the frequencies tested after acute noise damage, however, PAC1R−/− mice showed a larger elevation of the auditory threshold than did their WT counterparts. By contrast, in a transgene copy number-dependent fashion, TgHPAC1R mice showed smaller noise-induced elevations of auditory thresholds compared to their WT counterparts. Together, these findings suggest that PACAP could be a candidate for endogenous protection against noise-induced hearing loss.
Collapse
Affiliation(s)
- Jérôme Ruel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France.,Laboratoire de Neurosciences Cognitives, UMR7291 CNRS, Aix-Marseille Université, Marseille, France
| | - Matthieu J Guitton
- CERVO Brain Research Center, Faculty of Medicine, Laval University, Quebec City, QC, Canada
| | - Paul Gratias
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Marc Lenoir
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Sanbing Shen
- Regenerative Medicine Institute, National University of Ireland (NUI), Galway, Ireland
| | - Jean-Luc Puel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Philippe Brabet
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Jing Wang
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| |
Collapse
|
16
|
Effects of Pacap on Schwann Cells: Focus on Nerve Injury. Int J Mol Sci 2020; 21:ijms21218233. [PMID: 33153152 PMCID: PMC7663204 DOI: 10.3390/ijms21218233] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/23/2020] [Accepted: 11/02/2020] [Indexed: 12/27/2022] Open
Abstract
Schwann cells, the most abundant glial cells of the peripheral nervous system, represent the key players able to supply extracellular microenvironment for axonal regrowth and restoration of myelin sheaths on regenerating axons. Following nerve injury, Schwann cells respond adaptively to damage by acquiring a new phenotype. In particular, some of them localize in the distal stump to form the Bungner band, a regeneration track in the distal site of the injured nerve, whereas others produce cytokines involved in recruitment of macrophages infiltrating into the nerve damaged area for axonal and myelin debris clearance. Several neurotrophic factors, including pituitary adenylyl cyclase-activating peptide (PACAP), promote survival and axonal elongation of injured neurons. The present review summarizes the evidence existing in the literature demonstrating the autocrine and/or paracrine action exerted by PACAP to promote remyelination and ameliorate the peripheral nerve inflammatory response following nerve injury.
Collapse
|
17
|
Cryo-EM structure of the human PAC1 receptor coupled to an engineered heterotrimeric G protein. Nat Struct Mol Biol 2020; 27:274-280. [PMID: 32157248 DOI: 10.1038/s41594-020-0386-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/23/2020] [Indexed: 01/17/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic neuropeptide hormone. The PACAP receptor PAC1R, which belongs to the class B G-protein-coupled receptors (GPCRs), is a drug target for mental disorders and dry eye syndrome. Here, we present a cryo-EM structure of human PAC1R bound to PACAP and an engineered Gs heterotrimer. The structure revealed that transmembrane helix TM1 plays an essential role in PACAP recognition. The extracellular domain (ECD) of PAC1R tilts by ~40° compared with that of the glucagon-like peptide-1 receptor (GLP-1R) and thus does not cover the peptide ligand. A functional analysis demonstrated that the PAC1R ECD functions as an affinity trap and is not required for receptor activation, whereas the GLP-1R ECD plays an indispensable role in receptor activation, illuminating the functional diversity of the ECDs in class B GPCRs. Our structural information will facilitate the design and improvement of better PAC1R agonists for clinical applications.
Collapse
|
18
|
Wang J, Song X, Zhang D, Chen X, Li X, Sun Y, Li C, Song Y, Ding Y, Ren R, Harrington EH, Hu LA, Zhong W, Xu C, Huang X, Wang HW, Ma Y. Cryo-EM structures of PAC1 receptor reveal ligand binding mechanism. Cell Res 2020; 30:436-445. [PMID: 32047270 PMCID: PMC7196072 DOI: 10.1038/s41422-020-0280-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/20/2020] [Indexed: 12/24/2022] Open
Abstract
The pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1R) belongs to the secretin receptor family and is widely distributed in the central neural system and peripheral organs. Abnormal activation of the receptor mediates trigeminovascular activation and sensitization, which is highly related to migraine, making PAC1R a potential therapeutic target. Elucidation of PAC1R activation mechanism would benefit discovery of therapeutic drugs for neuronal disorders. PAC1R activity is governed by pituitary adenylate cyclase-activating polypeptide (PACAP), known as a major vasodilator neuropeptide, and maxadilan, a native peptide from the sand fly, which is also capable of activating the receptor with similar potency. These peptide ligands have divergent sequences yet initiate convergent PAC1R activity. It is of interest to understand the mechanism of PAC1R ligand recognition and receptor activity regulation through structural biology. Here we report two near-atomic resolution cryo-EM structures of PAC1R activated by PACAP38 or maxadilan, providing structural insights into two distinct ligand binding modes. The structures illustrate flexibility of the extracellular domain (ECD) for ligands with distinct conformations, where ECD accommodates ligands in different orientations while extracellular loop 1 (ECL1) protrudes to further anchor the ligand bound in the orthosteric site. By structure-guided molecular modeling and mutagenesis, we tested residues in the ligand-binding pockets and identified clusters of residues that are critical for receptor activity. The structures reported here for the first time elucidate the mechanism of specificity and flexibility of ligand recognition and binding for PAC1R, and provide insights toward the design of therapeutic molecules targeting PAC1R.
Collapse
Affiliation(s)
- Jia Wang
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xianqiang Song
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Dandan Zhang
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Xiaoqing Chen
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Xun Li
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Yaping Sun
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Cui Li
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Yunpeng Song
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Yao Ding
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Ruobing Ren
- School of Life and Health Sciences, Kobilka Institute of Innovative Drug Discovery, The Chinese University of Hong Kong, Tu H.L. Building (Research Building B) R705, Longxiang Road 2001, Longgang district, Shenzhen, 518172, Guangdong, China
| | - Essa Hu Harrington
- Hybrid Modality Engineering, Therapeutic Discovery, Amgen Research, One Amgen Center Dr., Thousand Oaks, CA, 91320, USA
| | - Liaoyuan A Hu
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Wenge Zhong
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Cen Xu
- Department of Neuroscience, Amgen Research, One Amgen Center Dr., Thousand Oaks, CA, 91320, USA
| | - Xin Huang
- Molecular Engineering, Therapeutic Discovery, Amgen Research, 360 Binney Street, Cambridge, MA, 02142, USA
| | - Hong-Wei Wang
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
| | - Yingli Ma
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China.
| |
Collapse
|
19
|
Pedersen SH, la Cour SH, Calloe K, Hauser F, Olesen J, Klaerke DA, Jansen-Olesen I. PACAP-38 and PACAP(6-38) Degranulate Rat Meningeal Mast Cells via the Orphan MrgB 3-Receptor. Front Cell Neurosci 2019; 13:114. [PMID: 30983973 PMCID: PMC6447718 DOI: 10.3389/fncel.2019.00114] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 03/08/2019] [Indexed: 12/12/2022] Open
Abstract
Infusion of pituitary adenylate cyclase activating peptide-38 (PACAP-38) provokes migraine attacks in migraineurs and headache in non-migraineurs. Adverse events like long-lasting flushing and heat sensation can be terminated with oral antihistamine treatment, indicating the involvement of mast cell activation after PACAP-infusion. Degranulation of rat peritoneal mast cells was provoked by several isoforms of PACAP via previously unknown receptor pharmacology. The effect might thus be mediated either via specific splice variants of the PAC1-receptor or via an unknown receptor for PACAP-38. In the present study, we characterize degranulation of rat meningeal mast cells in response to PACAP-receptor ligands. Furthermore, we investigate if PACAP-38-induced mast cell degranulation is mediated via PAC1-receptor splice variants and/or via the orphan Mas-related G-protein coupled member B3 (MrgB3)-receptor. To address this, the pharmacological effect of different PACAP isoforms on meningeal mast cell degranulation was investigated in the hemisected skull model after toluidine blue staining followed by microscopic quantification. Presence of mRNA encoding PAC1-receptor splice variants and the MrgB3-receptor in rat mast cells was investigated by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) analysis. The effect of PACAP isoforms on PAC1- and MrgB3-receptor-expressing Xenopus laevis oocytes were performed by two-electrode voltage-clamp (TEVC) electrophysiology. PACAP-38 is a more potent mast cell degranulating agent than Pituitary Adenylate Cyclase Activating Peptide-27 (PACAP-27) in the meninges. Presence of mRNA encoding the PAC1-receptor and its different splice variants could not be detected in peritoneal mast cells by RT-PCR, whereas the orphan MrgB3-receptor, recently suggested to be a mediator of basic secretagogues-induced mast cell degranulation, was widely present. In PAC1-receptor-expressing Xenopus laevis oocytes both PACAP-38, PACAP-27 and the specific PAC1-receptor agonist maxadilan were equipotent, however, only PACAP-38 showed a significant degranulatory effect on mast cells. We confirmed Pituitary Adenylate Cyclase Activating Peptide(6–38) [PACAP(6–38)] to be a PAC1-receptor antagonist, and we demonstrated that it is a potent mast cell degranulator and have an agonistic effect on MrgB3-receptors expressed in oocytes. The present study provides evidence that PACAP-induced mast cell degranulation in rat is mediated through a putative new PACAP-receptor with the order of potency being: PACAP-38 = PACAP(6–38) > > PACAP-27 = maxadilan. The results suggest that the observed responses are mediated via the orphan MrgB3-receptor.
Collapse
Affiliation(s)
- Sara Hougaard Pedersen
- Glostrup Research Institute, Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sanne Hage la Cour
- Glostrup Research Institute, Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kirstine Calloe
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Frank Hauser
- Cell and Neurobiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jes Olesen
- Glostrup Research Institute, Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dan Arne Klaerke
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Inger Jansen-Olesen
- Glostrup Research Institute, Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
20
|
Barrett KT, Hasan SU, Scantlebury MH, Wilson RJA. Impaired neonatal cardiorespiratory responses to hypoxia in mice lacking PAC1 or VPAC2 receptors. Am J Physiol Regul Integr Comp Physiol 2019; 316:R594-R606. [PMID: 30758978 DOI: 10.1152/ajpregu.00250.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The stress peptide pituitary adenylate cyclase activating polypeptide (PACAP) and its specific receptor PACAP type 1 receptor (PAC1) have been implicated in sudden infant death syndrome (SIDS). PACAP is also critical to the neonatal cardiorespiratory response to homeostatic stressors identified in SIDS, including hypoxia. However, which of PACAP's three receptors, PAC1, vasoactive intestinal peptide receptor type 1 (VPAC1), and/or vasoactive intestinal peptide receptor type 2 (VPAC2), are involved is unknown. In this study, we hypothesized that PAC1, but not VPAC2, is involved in mediating the cardiorespiratory response to hypoxia during neonatal development. To test this hypothesis, head-out plethysmography and surface ECG electrodes were used to assess the cardiorespiratory variables of unanesthetized postnatal day 4 PAC1 and VPAC2-knockout (KO) and wild-type (WT) mice in response to a 10% hypoxic challenge. Our results demonstrate that compared with WT pups, the early and late hypoxic rate of expired CO2 (V̇co2), V̇co2 and ventilatory responses were blunted in PAC1-KO neonates, and during the posthypoxic period, minute ventilation (V̇e), V̇co2 and heart rate were increased, while the increase in apneas normally associated with the posthypoxic period was reduced. Consistent with impaired cardiorespiratory control in these animals, the V̇e/V̇co2 slope was reduced in PAC1-KO pups, suggesting that breathing was inappropriately matched to metabolism. In contrast, VPAC2-KO pups exhibited elevated heart rate variability during hypoxia compared with WT littermates, but the effects of the VPAC2-KO genotype on breathing were minimal. These findings suggest that PAC1 plays the principal role in mediating the cardiorespiratory effects of PACAP in response to hypoxic stress during neonatal development and that defective PACAP signaling via PAC1 may contribute to the pathogenesis of SIDS.
Collapse
Affiliation(s)
- Karlene T Barrett
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary , Calgary, Alberta , Canada
| | - Shabih U Hasan
- Department of Pediatrics, Alberta Children's Hospital Research Institute, University of Calgary , Calgary, Alberta , Canada
| | - Morris H Scantlebury
- Department of Pediatrics, Clinical Neuroscience, Alberta Children's Hospital Research Institute, University of Calgary , Calgary, Alberta , Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary , Calgary, Alberta , Canada
| |
Collapse
|
21
|
Rubio-Beltrán E, Correnti E, Deen M, Kamm K, Kelderman T, Papetti L, Vigneri S, MaassenVanDenBrink A, Edvinsson L. PACAP38 and PAC 1 receptor blockade: a new target for headache? J Headache Pain 2018; 19:64. [PMID: 30088106 PMCID: PMC6081277 DOI: 10.1186/s10194-018-0893-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 07/24/2018] [Indexed: 12/21/2022] Open
Abstract
Pituitary adenylate cyclase activating polypeptide-38 (PACAP38) is a widely distributed neuropeptide involved in neuroprotection, neurodevelopment, nociception and inflammation. Moreover, PACAP38 is a potent inducer of migraine-like attacks, but the mechanism behind this has not been fully elucidated. Migraine is a neurovascular disorder, recognized as the second most disabling disease. Nevertheless, the antibodies targeting calcitonin gene-related peptide (CGRP) or its receptor are the only prophylactic treatment developed specifically for migraine. These antibodies have displayed positive results in clinical trials, but are not effective for all patients; therefore, new pharmacological targets need to be identified. Due to the ability of PACAP38 to induce migraine-like attacks, its location in structures previously associated with migraine pathophysiology and the 100-fold selectivity for the PAC1 receptor when compared to VIP, new attention has been drawn to this pathway and its potential role as a novel target for migraine treatment. In accordance with this, antibodies against PACAP38 (ALD 1910) and PAC1 receptor (AMG 301) are being developed, with AMG 301 already in Phase II clinical trials. No results have been published so far, but in preclinical studies, AMG 301 has shown responses comparable to those observed with triptans. If these antibodies prove to be effective for the treatment of migraine, several considerations should be addressed, for instance, the potential side effects of long-term blockade of the PACAP (receptor) pathway. Moreover, it is important to investigate whether these antibodies will indeed represent a therapeutic advantage for the patients that do not respond the CGRP (receptor)-antibodies. In conclusion, the data presented in this review indicate that PACAP38 and PAC1 receptor blockade are promising antimigraine therapies, but results from clinical trials are needed in order to confirm their efficacy and side effect profile.
Collapse
Affiliation(s)
- Eloisa Rubio-Beltrán
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Edvige Correnti
- Department of Child Neuropsychiatry, University of Palermo, Palermo, Italy
| | - Marie Deen
- Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Glostrup, Denmark
| | - Katharina Kamm
- Department of Neurology, University Hospital, LMU Munich, Munich, Germany
| | - Tim Kelderman
- Department of Neurology, Ghent University Hospital, Ghent, Belgium
| | - Laura Papetti
- Headache Center, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Simone Vigneri
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo; Pain Medicine Unit, Santa Maria Maddalena Hospital, Occhiobello, Italy
| | - Antoinette MaassenVanDenBrink
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Lars Edvinsson
- Department of Internal Medicine, Institute of Clinical Sciences, Lund University, Lund, Sweden
| | | |
Collapse
|
22
|
Schober DA, Croy CH, Ruble CL, Tao R, Felder CC. Identification, expression and functional characterization of M4L, a muscarinic acetylcholine M4 receptor splice variant. PLoS One 2017; 12:e0188330. [PMID: 29211764 PMCID: PMC5718406 DOI: 10.1371/journal.pone.0188330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/03/2017] [Indexed: 11/24/2022] Open
Abstract
Rodent genomic alignment sequences support a 2-exon model for muscarinic M4 receptor. Using this model a novel N-terminal extension was discovered in the human muscarinic acetylcholine M4 receptor. An open reading frame was discovered in the human, mouse and rat with a common ATG (methionine start codon) that extended the N-terminus of the muscarinic acetylcholine M4 receptor subtype by 155 amino acids resulting in a longer variant. Transcriptional evidence for this splice variant was confirmed by RNA-Seq and RT-PCR experiments performed from human donor brain prefrontal cortices. We detected a human upstream exon indicating the translation of the mature longer M4 receptor transcript. The predicted size for the longer two-exon M4 receptor splice variant with the additional 155 amino acid N-terminal extension, designated M4L is 69.7 kDa compared to the 53 kDa canonical single exon M4 receptor (M4S). Western blot analysis from a mammalian overexpression system, and saturation radioligand binding with [3H]-NMS (N-methyl-scopolamine) demonstrated the expression of this new splice variant. Comparative pharmacological characterization between the M4L and M4S receptors revealed that both the orthosteric and allosteric binding sites for both receptors were very similar despite the addition of an N-terminal extension.
Collapse
Affiliation(s)
- Douglas A. Schober
- Neuroscience, Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Carrie H. Croy
- Neuroscience, Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Cara L. Ruble
- Neuroscience, Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Ran Tao
- Lieber Institute for Brain Development, Baltimore, Maryland, United States of America
| | - Christian C. Felder
- Neuroscience, Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, Indiana, United States of America
- * E-mail:
| |
Collapse
|
23
|
Sundrum T, Walker CS. Pituitary adenylate cyclase-activating polypeptide receptors in the trigeminovascular system: implications for migraine. Br J Pharmacol 2017; 175:4109-4120. [PMID: 28977676 DOI: 10.1111/bph.14053] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 08/24/2017] [Accepted: 09/11/2017] [Indexed: 12/13/2022] Open
Abstract
The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) has been implicated in a wide range of functions including vasodilatation, neuroprotection, nociception and neurogenic inflammation. PACAP activates three distinct receptors, the PAC1 receptor, which responds to PACAP, and the VPAC1 and VPAC2 receptors, which respond to both PACAP and vasoactive intestinal polypeptide. The trigeminovascular system plays a key role in migraine and contains the trigeminal nerve, which is the major conduit of craniofacial pain. PACAP is expressed throughout the trigeminovascular system and in higher brain regions involved in processing pain. Evidence from human clinical studies suggests that PACAP may act outside the blood-brain barrier in the pathogenesis of migraine. However, the precise mechanisms involved remain unclear. PACAP potentially induces migraine attacks by activating different receptors in different cell types and tissues. This complexity prompted this review of PACAP receptor pharmacology, expression and function in the trigeminovascular system. Current evidence suggests that the PAC1 receptor is the likely pathophysiological target of PACAP in migraine. However, multiple PACAP receptors are expressed in key parts of the trigeminovascular system and further work is required to determine their contribution to PACAP physiology and the pathology of migraine. LINKED ARTICLES This article is part of a themed section on Molecular Pharmacology of GPCRs. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.21/issuetoc.
Collapse
Affiliation(s)
- Tahlia Sundrum
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Christopher S Walker
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre and Centre for Brain Research, University of Auckland, Auckland, New Zealand
| |
Collapse
|
24
|
Sághy É, Payrits M, Helyes Z, Reglődi D, Bánki E, Tóth G, Couvineau A, Szőke É. Stimulatory effect of pituitary adenylate cyclase-activating polypeptide 6-38, M65 and vasoactive intestinal polypeptide 6-28 on trigeminal sensory neurons. Neuroscience 2015; 308:144-56. [PMID: 26321242 DOI: 10.1016/j.neuroscience.2015.08.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/31/2015] [Accepted: 08/20/2015] [Indexed: 02/08/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) acts on G protein-coupled receptors: the specific PAC1 and VPAC1/VPAC2 receptors. PACAP6-38 was described as a potent PAC1/VPAC2 antagonist in several models, but recent studies reported its agonistic behaviors proposing novel receptorial mechanisms. Since PACAP in migraine is an important research tool, we investigated the effect of PACAP and its peptide fragments on trigeminal primary sensory neurons. Effect of the peptides was studied with ratiometric Ca-imaging technique using the fluorescent indicator fura-2 AM on primary cultures of rat and mouse trigeminal ganglia (TRGs) neurons. Specificity testing was performed on PAC1, VPAC1 and VPAC2 receptor-expressing cell lines with both fluorescent and radioactive Ca-uptake methods. Slowly increasing intracellular free calcium concentration [Ca(2+)]i was detected after PACAP1-38, PACAP1-27, vasoactive intestinal polypeptide (VIP) and the selective PAC1 receptor agonist maxadilan administration on TRG neurons, but interestingly, PACAP6-38, VIP6-28 and the PAC1 receptor antagonist M65 also caused similar activation. The VPAC2 receptor agonist BAY 55-9837 induced similar activation, while the VPAC1 receptor agonist Ala(11,22,28)VIP had no significant effect on [Ca(2+)]i. It was proven that the Ca(2+)-influx originated from intracellular stores using radioactive calcium-45 uptake experiment and Ca-free solution. On the specific receptor-expressing cell lines the antagonists inhibited the stimulating actions of the respective agonists, but had no effects by themselves. PACAP6-38, M65 and VIP6-28, which were described as antagonists in numerous studies in several model systems, act as agonists on TRG primary sensory neurons. Currently unknown receptors or splice variants linked to distinct signal transduction pathways might explain these differences.
Collapse
MESH Headings
- Animals
- CHO Cells
- Calcium/metabolism
- Cells, Cultured
- Cricetulus
- Humans
- Insect Proteins/pharmacology
- Mice
- Peptide Fragments/pharmacology
- Pituitary Adenylate Cyclase-Activating Polypeptide/pharmacology
- Rats, Wistar
- Receptors, Vasoactive Intestinal Peptide, Type II/antagonists & inhibitors
- Receptors, Vasoactive Intestinal Peptide, Type II/metabolism
- Receptors, Vasoactive Intestinal Polypeptide, Type I/agonists
- Receptors, Vasoactive Intestinal Polypeptide, Type I/metabolism
- Sensory Receptor Cells/drug effects
- Sensory Receptor Cells/physiology
- Sensory System Agents/pharmacology
- TRPV Cation Channels/metabolism
- Trigeminal Ganglion/drug effects
- Trigeminal Ganglion/physiology
- Vasoactive Intestinal Peptide/pharmacology
- Voltage-Sensitive Dye Imaging
Collapse
Affiliation(s)
- É Sághy
- Department of Pharmacology and Pharmacotherapy, MTA-PTE Chronic Pain Research Group, Szentágothai Research Center, University of Pécs, Pécs-7624, Szigeti Street 12, Hungary.
| | - M Payrits
- Department of Pharmacology and Pharmacotherapy, MTA-PTE Chronic Pain Research Group, Szentágothai Research Center, University of Pécs, Pécs-7624, Szigeti Street 12, Hungary.
| | - Zs Helyes
- Department of Pharmacology and Pharmacotherapy, MTA-PTE Chronic Pain Research Group, Szentágothai Research Center, University of Pécs, Pécs-7624, Szigeti Street 12, Hungary.
| | - D Reglődi
- Department of Anatomy, MTA-PTE "Lendület" PACAP Research Team, University of Pécs, Pécs-7624, Szigeti Street 12, Hungary.
| | - E Bánki
- Department of Anatomy, MTA-PTE "Lendület" PACAP Research Team, University of Pécs, Pécs-7624, Szigeti Street 12, Hungary.
| | - G Tóth
- Department of Medical Chemistry, University of Szeged, Szeged-6720, Dugonics Street 13, Hungary.
| | - A Couvineau
- UMR 1149 INSERM/Centre de Recherche sur l'Inflammation, Université Paris Diderot, Faculte de Medecine Paris 7 - Site Bichat, 16 Rue Henri Huchard, 75890 Paris Cedex 18, France.
| | - É Szőke
- Department of Pharmacology and Pharmacotherapy, MTA-PTE Chronic Pain Research Group, Szentágothai Research Center, University of Pécs, Pécs-7624, Szigeti Street 12, Hungary.
| |
Collapse
|
25
|
Hald H, Wu B, Bouakaz L, Meldal M. A single-vector EYFP reporter gene assay for G protein-coupled receptors. Anal Biochem 2015; 476:40-4. [DOI: 10.1016/j.ab.2015.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 02/01/2015] [Accepted: 02/03/2015] [Indexed: 10/24/2022]
|
26
|
Walker CS, Sundrum T, Hay DL. PACAP receptor pharmacology and agonist bias: analysis in primary neurons and glia from the trigeminal ganglia and transfected cells. Br J Pharmacol 2014; 171:1521-33. [PMID: 24303997 DOI: 10.1111/bph.12541] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 11/25/2013] [Accepted: 11/29/2013] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE A major challenge in the development of new medicines targeting GPCRs is the ability to quantify drug action in physiologically relevant models. Primary cell models that closely resemble the clinically relevant in vivo site of drug action are important translational tools in drug development. However, pharmacological studies in these models are generally very limited due to the methodology used. EXPERIMENTAL APPROACH We used a neuropeptide system to demonstrate the applicability of using highly sensitive signalling assays in primary cells. We quantified the action of pituitary adenylate cyclase-activating peptide (PACAP)-38, PACAP-27 and vasoactive intestinal polypeptide in primary cultures of neurons and glia derived from rat trigeminal ganglia (TG), comparing our observations to transfected cells. KEY RESULTS PACAP-responsive receptors in rat trigeminal neurons, glia and transfected PAC1n receptors were pharmacologically distinct. PACAP-38, but not PACAP-27, activated ERK in glia, while both forms stimulated cellular cAMP production. PACAP(6-38) also displayed cell-type-dependent, agonist-specific, antagonism. CONCLUSIONS AND IMPLICATIONS The complexity of PACAP pharmacology in the TG may help to direct, more effectively, the development of disease treatments targeting the PACAP receptor. We suggest that these methodologies are broadly applicable to other primary cell types of human or animal origin, and that our approach may allow more thorough characterization of ligand properties in physiologically relevant cell types.
Collapse
Affiliation(s)
- C S Walker
- School of Biological Sciences, University of Auckland, Auckland, New Zealand; Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | | | | |
Collapse
|
27
|
Bonner TI. Should pharmacologists care about alternative splicing? IUPHAR Review 4. Br J Pharmacol 2014; 171:1231-40. [PMID: 24670145 DOI: 10.1111/bph.12526] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/27/2013] [Accepted: 11/13/2013] [Indexed: 11/29/2022] Open
Abstract
Alternative splicing of mRNAs occurs in the majority of human genes, and most differential splicing results in different protein isoforms with possibly different functional properties. However, there are many reported splicing variations that may be quite rare, and not all combinatorially possible variants of a given gene are expressed at significant levels. Genes of interest to pharmacologists are frequently expressed at such low levels that they are not adequately represented in genome-wide studies of transcription. In single-gene studies, data are commonly available on the relative abundance and functional significance of individual alternatively spliced exons, but there are rarely data that quantitate the relative abundance of full-length transcripts and define which combinations of exons are significant. A number of criteria for judging the significance of splice variants and suggestions for their nomenclature are discussed.
Collapse
Affiliation(s)
- T I Bonner
- National Institute of Mental Health, Bethesda, MD, USA
| |
Collapse
|
28
|
Wu L, Guang W, Chen X, Hong A. Homology modeling and molecular docking of human pituitary adenylate cyclase‑activating polypeptide I receptor. Mol Med Rep 2014; 10:1691-6. [PMID: 25069645 PMCID: PMC4148375 DOI: 10.3892/mmr.2014.2419] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 05/02/2014] [Indexed: 01/30/2023] Open
Abstract
Pituitary adenylate cyclase-activating peptide I receptor (PAC1R) is member of the B class of G protein-coupled seven-transmembrane receptors, with molecular functions associated with neural cell differentiation, regeneration and the inhibition of apoptosis. However, the integrity of the protein structure is difficult to be determined in vitro. In the present study, the physicochemical properties of PAC1R were analyzed, the extracellular, transmembrane and intracellular regions were constructed and a three-dimensional structure model of PAC1R was produced using extracellular loop region optimization and the energy minimization homology modeling method. Preliminary studies on the PAC1R protein and ligand interactions used a molecular docking method. The results indicated that the interaction sites of PAC1R were at Ile63, Ser100 and Gln105. These were the sites where the PAC1R combined with a hydrazide small molecule inhibitor. This study provides a theoretical basis for further studies on the model for the development of PAC1R target drugs.
Collapse
Affiliation(s)
- Lusheng Wu
- Biomedicine Institute, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Wenhua Guang
- Biomedicine Institute, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Xiaojia Chen
- Biomedicine Institute, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - An Hong
- Biomedicine Institute, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| |
Collapse
|
29
|
Wojcieszak J, Zawilska JB. PACAP38 and PACAP6-38 exert cytotoxic activity against human retinoblastoma Y79 cells. J Mol Neurosci 2014; 54:463-8. [PMID: 24515671 PMCID: PMC4221657 DOI: 10.1007/s12031-014-0248-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 01/21/2014] [Indexed: 01/20/2023]
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) is a multifunctional neuropeptide expression of which has been found in various tumors of the brain and peripheral organs. Despite numerous studies, the exact role the peptide plays in the development and progression of tumors is not fully understood. In the present study, we investigated the effect of PACAP on human retinoblastoma Y79 cell viability. We found that both PACAP38 and PACAP6-38, a selective PAC1 receptor antagonist, did not affect Y79 cell viability at nanomolar concentrations, but when used at 1-5 μM potently reduced cell survival in a dose-dependent manner. PACAP27 and maxadilan, a high affinity agonist of PAC1 receptors, had negligible effects. Two membrane-penetrating analogs of PACAP38 inactive at PAC1/VPAC receptors, [Disc(6)]PACAP38 and FITC-Ahx-PACAP11-38, also decreased viability of Y79 cells, albeit with lower potency than PACAP38. The cytotoxic effect of PACAP38 was augmented by p38, MEK1/2, and JNK inhibitors, indicating that high concentrations of the peptide might decrease the activity of these kinases, leading to cell death. It is suggested that the cytotoxic activity of PACAP38 and PACAP6-38 against human retinoblastoma Y79 cell line may result from their interaction with target sites other than PAC1 and VPAC receptors, but this is yet unknown.
Collapse
Affiliation(s)
- Jakub Wojcieszak
- Department of Pharmacodynamics, Medical University of Lodz, Muszynskiego 1 Street, Lodz, 90-151, Poland
| | | |
Collapse
|
30
|
Shen S, Gehlert DR, Collier DA. PACAP and PAC1 receptor in brain development and behavior. Neuropeptides 2013; 47:421-30. [PMID: 24220567 DOI: 10.1016/j.npep.2013.10.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 10/12/2013] [Accepted: 10/13/2013] [Indexed: 10/26/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) act through three class B G-protein coupled receptors, PAC1, VPAC1 and VPAC2, initiating multiple signaling pathways. In addition to natural peptides ligands, a number of synthetic peptides and a small molecular antagonist have been generated. Genetically modified animals have been produced for the neuropeptides and receptors. Neuroanatomical, electrophysiological, behavioral and pharmacological characterization of the mutants and transgenic mice uncovered diverse roles of PACAP-PAC1-VAPC2 signaling in peripheral tissues and in the central nervous system. Human genetic studies suggest that the PACAP-PAC1-VPAC2 signaling can be associated with psychiatric illness via mechanisms of not only loss-of-function, but also gain-of-function. For example, a duplication of chromosome 7q36.3 (encoding the VPAC2 receptor) was shown to be associated with schizophrenia, and high levels of PACAP-PAC1 signaling are associated with posttraumatic stress disorder. Whereas knockout animals are appropriate to address loss-of-function of human genetics, transgenic mice overexpressing human transgenes in native environment using artificial chromosomes are particularly valuable and essential to address the consequences of gain-of-function. This review focuses on role of PACAP and PAC1 receptor in brain development, behavior of animals and potential implication in human neurodevelopmental disorders. It also encourages keeping an open mind that alterations of VIP/PACAP signaling may associate with psychiatric illness without overt neuroanatomic changes, and that tuning of VIP/PACAP signaling may represent a novel avenue for the treatment of the psychiatric illness.
Collapse
Affiliation(s)
- Sanbing Shen
- Regenerative Medicine Institute, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland.
| | | | | |
Collapse
|
31
|
Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: G protein-coupled receptors. Br J Pharmacol 2013; 170:1459-581. [PMID: 24517644 PMCID: PMC3892287 DOI: 10.1111/bph.12445] [Citation(s) in RCA: 505] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. G protein-coupled receptors are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
Collapse
Affiliation(s)
- Stephen PH Alexander
- School of Life Sciences, University of Nottingham Medical SchoolNottingham, NG7 2UH, UK
| | - Helen E Benson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Elena Faccenda
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Adam J Pawson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Joanna L Sharman
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | | | - John A Peters
- Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of DundeeDundee, DD1 9SY, UK
| | - Anthony J Harmar
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| |
Collapse
|
32
|
STC1 induction by PACAP is mediated through cAMP and ERK1/2 but not PKA in cultured cortical neurons. J Mol Neurosci 2013; 46:75-87. [PMID: 21975601 DOI: 10.1007/s12031-011-9653-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 09/15/2011] [Indexed: 10/17/2022]
Abstract
The neuroprotective actions of PACAP (pituitary adenylate cyclase-activating polypeptide) in vitro and in vivo suggest that activation of its cognate G protein coupled receptor PAC1 or downstream signaling molecules,and thus activation of PACAP target genes, could be of therapeutic benefit. Here, we show that cultured rat cortical neurons predominantly expressed the PAC1hop and null variants. PACAP receptor activation resulted in the elevation of the two second messengers cAMP and Ca(2+) and expression of the putative neuroprotectant stanniocalcin 1(STC1). PACAP signaling to the STC1 gene proceeded through the extracellular signal-regulated kinases 1 and 2(ERK1/2), but not through the cAMP-dependent protein kinase (PKA), and was mimicked by the adenylate cyclase activator forskolin. PACAP- and forskolin-mediated activation of ERK1/2 occurred through cAMP, but not PKA.These results suggest that STC1 gene induction proceeds through cAMP and ERK1/2, independently of PKA, the canonical cAMP effector. In contrast, PACAP signaling to the BDNF gene proceeded through PKA, suggesting that two different neuroprotective cAMP pathways co-exist in differentiated cortical neurons. The selective activation of a potentially neuroprotective cAMP-dependent pathway different from the canonical cAMP pathway used in many physiological processes, such as memory storage, has implications for pharmacological activation of neuroprotection in vivo.
Collapse
|
33
|
Blechman J, Levkowitz G. Alternative Splicing of the Pituitary Adenylate Cyclase-Activating Polypeptide Receptor PAC1: Mechanisms of Fine Tuning of Brain Activity. Front Endocrinol (Lausanne) 2013; 4:55. [PMID: 23734144 PMCID: PMC3659299 DOI: 10.3389/fendo.2013.00055] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Accepted: 04/24/2013] [Indexed: 12/11/2022] Open
Abstract
Alternative splicing of the precursor mRNA encoding for the neuropeptide receptor PAC1/ADCYAP1R1 generates multiple protein products that exhibit pleiotropic activities. Recent studies in mammals and zebrafish have implicated some of these splice isoforms in control of both cellular and body homeostasis. Here, we review the regulation of PAC1 splice variants and their underlying signal transduction and physiological processes in the nervous system.
Collapse
Affiliation(s)
- Janna Blechman
- Department of Molecular Cell Biology, Weizmann Institute of ScienceRehovot, Israel
| | - Gil Levkowitz
- Department of Molecular Cell Biology, Weizmann Institute of ScienceRehovot, Israel
- *Correspondence: Gil Levkowitz, Department of Molecular Cell Biology, Weizmann Institute of Science, P. O. Box 26, Rehovot 76100, Israel. e-mail:
| |
Collapse
|
34
|
Furness SGB, Wootten D, Christopoulos A, Sexton PM. Consequences of splice variation on Secretin family G protein-coupled receptor function. Br J Pharmacol 2012; 166:98-109. [PMID: 21718310 DOI: 10.1111/j.1476-5381.2011.01571.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The Secretin family of GPCRs are endocrine peptide hormone receptors that share a common genomic organization and are the subject of a wide variety of alternative splicing. All GPCRs contain a central seven transmembrane domain responsible for transducing signals from the outside of the cell as well as extracellular amino and intracellular carboxyl termini. Members of the Secretin receptor family have a relatively large N-terminus and a variety of lines of evidence support a common mode of ligand binding and a common ligand binding fold. These receptors are best characterized as coupling to intracellular signalling pathways via G(αs) and G(αq) but are also reported to couple to a multitude of other signalling pathways. The intracellular loops are implicated in regulating the interaction between the receptor and heterotrimeric G protein complexes. Alternative splicing of exons encoding both the extracellular N-terminal domain as well as the extracellular loops of some family members has been reported and as expected these splice variants display altered ligand affinity as well as differential activation by endogenous ligands. Various forms of alternative splicing have also been reported to alter intracellular loops 1 and 3 as well as the C-terminus and as one might expect these display differences in signalling bias towards downstream effectors. These diverse pharmacologies require that the physiological role of these splice variants be addressed but should provide unique opportunities for drug design and development.
Collapse
|
35
|
Harmar AJ, Fahrenkrug J, Gozes I, Laburthe M, May V, Pisegna JR, Vaudry D, Vaudry H, Waschek JA, Said SI. Pharmacology and functions of receptors for vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide: IUPHAR review 1. Br J Pharmacol 2012; 166:4-17. [PMID: 22289055 DOI: 10.1111/j.1476-5381.2012.01871.x] [Citation(s) in RCA: 331] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are members of a superfamily of structurally related peptide hormones that includes glucagon, glucagon-like peptides, secretin, gastric inhibitory peptide (GIP) and growth hormone-releasing hormone (GHRH). VIP and PACAP exert their actions through three GPCRs - PAC(1) , VPAC(1) and VPAC(2) - belonging to class B (also referred to as class II, or secretin receptor-like GPCRs). This family comprises receptors for all peptides structurally related to VIP and PACAP, and also receptors for parathyroid hormone, corticotropin-releasing factor, calcitonin and related peptides. PAC(1) receptors are selective for PACAP, whereas VPAC(1) and VPAC(2) respond to both VIP and PACAP with high affinity. VIP and PACAP play diverse and important roles in the CNS, with functions in the control of circadian rhythms, learning and memory, anxiety and responses to stress and brain injury. Recent genetic studies also implicate the VPAC(2) receptor in susceptibility to schizophrenia and the PAC(1) receptor in post-traumatic stress disorder. In the periphery, VIP and PACAP play important roles in the control of immunity and inflammation, the control of pancreatic insulin secretion, the release of catecholamines from the adrenal medulla and as co-transmitters in autonomic and sensory neurons. This article, written by members of the International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature and Drug Classification (NC-IUPHAR) subcommittee on receptors for VIP and PACAP, confirms the existing nomenclature for these receptors and reviews our current understanding of their structure, pharmacology and functions and their likely physiological roles in health and disease. More detailed information has been incorporated into newly revised pages in the IUPHAR database (http://www.iuphar-db.org/DATABASE/FamilyMenuForward?familyId=67).
Collapse
|
36
|
Cloning and differential expression pattern of pituitary adenylyl cyclase-activating polypeptide and the PACAP-specific receptor in darkbarbel catfish Pelteobagrus vachelli. Comp Biochem Physiol B Biochem Mol Biol 2012; 161:41-53. [DOI: 10.1016/j.cbpb.2011.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 09/11/2011] [Accepted: 09/11/2011] [Indexed: 11/18/2022]
|
37
|
Pharmacological characterization and expression of VIP and PACAP receptors in isolated cranial arteries of the rat. Eur J Pharmacol 2011; 670:186-94. [DOI: 10.1016/j.ejphar.2011.08.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 07/20/2011] [Accepted: 08/17/2011] [Indexed: 11/17/2022]
|
38
|
Targeting VIP and PACAP receptor signalling: new therapeutic strategies in multiple sclerosis. ASN Neuro 2011; 3:AN20110024. [PMID: 21895607 PMCID: PMC3189630 DOI: 10.1042/an20110024] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
MS (multiple sclerosis) is a chronic autoimmune and neurodegenerative pathology of the CNS (central nervous system) affecting approx. 2.5 million people worldwide. Current and emerging DMDs (disease-modifying drugs) predominantly target the immune system. These therapeutic agents slow progression and reduce severity at early stages of MS, but show little activity on the neurodegenerative component of the disease. As the latter determines permanent disability, there is a critical need to pursue alternative modalities. VIP (vasoactive intestinal peptide) and PACAP (pituitary adenylate cyclase-activating peptide) have potent anti-inflammatory and neuroprotective actions, and have shown significant activity in animal inflammatory disease models including the EAE (experimental autoimmune encephalomyelitis) MS model. Thus, their receptors have become candidate targets for inflammatory diseases. Here, we will discuss the immunomodulatory and neuroprotective actions of VIP and PACAP and their signalling pathways, and then extensively review the structure–activity relationship data and biophysical interaction studies of these peptides with their cognate receptors.
Collapse
|
39
|
Holighaus Y, Mustafa T, Eiden LE. PAC1hop, null and hip receptors mediate differential signaling through cyclic AMP and calcium leading to splice variant-specific gene induction in neural cells. Peptides 2011; 32:1647-55. [PMID: 21693142 PMCID: PMC3163081 DOI: 10.1016/j.peptides.2011.06.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 06/05/2011] [Accepted: 06/06/2011] [Indexed: 11/19/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP)-mediated activation of its G protein-coupled receptor PAC1 results in activation of the two G proteins Gs and Gq to alter second messenger generation and gene transcription in the nervous system, important for homeostatic responses to stress and injury. Heterologous expression of the three major splice variants of the rat PAC1 receptor, PAC1hop, null and hip, in neural NG108-15 cells conferred PACAP-mediated intracellular cAMP generation, while elevation of [Ca(2+)](i) occurred only in PAC1hop-, and to a lesser extent in PAC1null-expressing cells. Induction of vasoactive intestinal polypeptide (VIP) and stanniocalcin 1 (STC1), two genes potentially involved in PACAP's homeostatic responses, was examined as a function of the expressed PAC1 variant. VIP induction was greatest in PAC1hop-expressing cells, suggesting that a maximal transcriptional response requires combinatorial signaling through both cAMP and Ca(2+). STC1 induction was similar for all three receptor splice variants and was mimicked by the adenylate cyclase activator forskolin, indicating that cAMP elevation is sufficient to induce STC1. The degree of activation of two different second messenger pathways appears to determine the transcriptional response, suggesting that cellular responses to stressors are fine-tuned through differential receptor isoform expression. Signaling to the VIP gene proceeded through cAMP and protein kinase A (PKA) in these cells, independently of the MAP kinase ERK1/2. STC1 gene induction by PACAP was dependent on cAMP and ERK1/2, independently of PKA. Differential gene induction via different cAMP dependent signaling pathways potentially provides further targets for the design of treatments for stress-associated disorders.
Collapse
Affiliation(s)
- Yvonne Holighaus
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, MD 20892, USA
| | | | | |
Collapse
|
40
|
Shneider Y, Shtrauss Y, Yadid G, Pinhasov A. Differential expression of PACAP receptors in postnatal rat brain. Neuropeptides 2010; 44:509-14. [PMID: 20971507 DOI: 10.1016/j.npep.2010.09.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 09/13/2010] [Accepted: 09/14/2010] [Indexed: 12/22/2022]
Abstract
Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) is a multi-functional neuropeptide that acts through activation of three common G-protein coupled receptors (VPAC1, VPAC2 and PAC1). In this study, we have investigated the gene expression profile of PAC1 isoforms (Hop1, Hip, Hip-Hop) and VPAC1, VPAC2 receptors in distinct brain regions during different stages of rat postnatal development. Using quantitative real time PCR approach we found that PAC1 isoforms were highly expressed in the cortex of newborns with marked decrease in expression during later stages of development. In contrast, mRNA levels of VPAC1, VPAC2 receptors were markedly lower in newborns in comparison to later developmental stages. Expression of PAC1 isoforms predominated in the hippocampus, while expression of VPAC1 was more prominent in the cortex and VPAC2 in the striatum and hippocampus. In addition we found that during early stages of postnatal development the expression of PAC1 receptor in the hippocampus was significantly higher in females than in males. No sex dependent differences in expression were observed for the VPAC1 and VPAC2 receptors. In summary, differential expression of PAC1, VPAC1 and VPAC2 receptors during postnatal development as well as gender dependent differences of PAC1 receptor expression in the hippocampus, will contribute to our understanding of the role of PACAP/VIP signaling system in normal brain development and function.
Collapse
Affiliation(s)
- Yevgenia Shneider
- Department of Molecular Biology, Ariel University Center of Samaria, Ariel, Israel
| | | | | | | |
Collapse
|
41
|
Yu R, Li J, Wang J, Liu X, Huang L, Ding Y, Chen J. The functional recombinant first extracellular (EC1) domain of PACAP receptor PAC1 normal form (PAC1-EC1(N)) recognizes selective ligands and stimulates the proliferation of PAC1-CHO cells. Neurosci Lett 2010; 480:73-7. [DOI: 10.1016/j.neulet.2010.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 05/26/2010] [Accepted: 06/02/2010] [Indexed: 11/16/2022]
|
42
|
Yi CX, Sun N, Ackermans MT, Alkemade A, Foppen E, Shi J, Serlie MJ, Buijs RM, Fliers E, Kalsbeek A. Pituitary adenylate cyclase-activating polypeptide stimulates glucose production via the hepatic sympathetic innervation in rats. Diabetes 2010; 59:1591-600. [PMID: 20357362 PMCID: PMC2889757 DOI: 10.2337/db09-1398] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE The unraveling of the elaborate brain networks that control glucose metabolism presents one of the current challenges in diabetes research. Within the central nervous system, the hypothalamus is regarded as the key brain area to regulate energy homeostasis. The aim of the present study was to investigate the hypothalamic mechanism involved in the hyperglycemic effects of the neuropeptide pituitary adenylyl cyclase-activating polypeptide (PACAP). RESEARCH DESIGN AND METHODS Endogenous glucose production (EGP) was determined during intracerebroventricular infusions of PACAP-38, vasoactive intestinal peptide (VIP), or their receptor agonists. The specificity of their receptors was examined by coinfusions of receptor antagonists. The possible neuronal pathway involved was investigated by 1) local injections in hypothalamic nuclei, 2) retrograde neuronal tracing from the thoracic spinal cord to hypothalamic preautonomic neurons together with Fos immunoreactivity, and 3) specific hepatic sympathetic or parasympathetic denervation to block the autonomic neuronal input to liver. RESULTS Intracerebroventricular infusion of PACAP-38 increased EGP to a similar extent as a VIP/PACAP-2 (VPAC2) receptor agonist, and intracerebroventricular administration of VIP had significantly less influence on EGP. The PACAP-38 induced increase of EGP was significantly suppressed by preinfusion of a VPAC2 but not a PAC1 receptor antagonist, as well as by hepatic sympathetic but not parasympathetic denervation. In the hypothalamus, Fos immunoreactivity induced by PACAP-38 was colocalized within autonomic neurons in paraventricular nuclei projecting to preganglionic sympathetic neurons in the spinal cord. Local infusion of PACAP-38 directly into the PVN induced a significant increase of EGP. CONCLUSIONS This study demonstrates that PACAP-38 signaling via sympathetic preautonomic neurons located in the paraventricular nucleus is an important component in the hypothalamic control of hepatic glucose production.
Collapse
Affiliation(s)
- Chun-Xia Yi
- Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Gutknecht E, Vauquelin G, Dautzenberg FM. Corticotropin-releasing factor receptors induce calcium mobilization through cross-talk with Gq-coupled receptors. Eur J Pharmacol 2010; 642:1-9. [PMID: 20594969 DOI: 10.1016/j.ejphar.2010.05.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 04/28/2010] [Accepted: 05/25/2010] [Indexed: 11/20/2022]
Abstract
The cross-talk between corticotropin-releasing factor (CRF) and muscarinic receptors was investigated by measuring evoked transient increases in cytosolic calcium concentration. HEK293 cells stably expressing human CRF type 1 (hCRF(1)) and type 2(a) (hCRF(2(a))) receptors were stimulated with the muscarinic receptor agonist carbachol and shortly after by a CRF agonist. Unexpectedly, this second response was enhanced when compared to stimulating naive cells either with carbachol or CRF agonist only. Priming with 100 microM carbachol increased the maximal CRF agonist response and shifted its concentration-response curve to the left to attain almost the same potency as for stimulating the production of the natural second messenger cyclic AMP. Yet, priming did not affect CRF agonist-stimulated cyclic AMP production itself. Carbachol priming was not restricted to recombinant CRF receptors only since endogenously expressed beta(2)-adrenoceptors also started to produce a robust calcium signal. Without priming no such signal was observed. Similar findings were made in the human retinoblastoma cell line Y79 for endogenously expressed CRF(1) receptors and the type 1 pituitary adenylate cyclase-activating polypeptide receptors but not for the CRF(2(a)) receptors. This differentiation between CRF(1) and CRF(2) receptors was further supported by use of selective agonists and antagonists. The results suggest that stimulating a Gq-coupled receptor shortly before stimulating a Gs-coupled receptor may result in a parallel signaling event on top of the classical cyclic AMP pathway.
Collapse
Affiliation(s)
- Eric Gutknecht
- Johnson & Johnson Research & Development, CNS Research, Turnhoutseweg 30, B-2340 Beerse, Belgium.
| | | | | |
Collapse
|
44
|
Ushiyama M, Ikeda R, Yoshida M, Mori K, Kangawa K, Sugawara H, Inoue K, Yamada K, Miyata A. Alternative splicing of the pituitary adenylate cyclase-activating polypetide (PACAP) receptor contributes to function of PACAP-27. J Mol Neurosci 2010; 42:341-8. [PMID: 20473586 DOI: 10.1007/s12031-010-9385-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 04/23/2010] [Indexed: 11/25/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP)-27 and PACAP-38 are neuropeptides performing a variety of physiological functions. The PACAP-specific receptor PAC1 has several variants that result mainly from alternative splicing in the mRNA region encoding the first extracellular (EC1) domain and the third intracellular cytoplasmic (IC3) loop. To characterize the molecular forms of alternative splicing variants of PAC1, we examined the binding affinity and activation of two major second messenger pathways (cAMP production and changes in [Ca(2+)]( i )) by PACAP-27. Activation of cAMP was influenced by the variant in both of the EC1 domain and IC3 loops. In the N form in the EC1 domain, the suppressive effect of the HOP1 form in the IC3 loop was enhanced. Regarding the intracellular calcium mobilization assay, the rank order of the potency of PACAP-27 for the different PAC1 isoforms was S/HOP1>>N/R~S/R>>N/HOP1. In particular, PACAP-27 exhibited remarkable potency of calcium mobilization in the S/HOP1-expressing cells at sub-picomolar concentrations even though the affinities of PACAP-27 to the four PAC1 isoforms were not significantly different. This suggests the specific functions of PACAP-27 due to PACAP-27 preferring PAC1 activation, and leads in clarification of the pleiotoropic function of PACAP.
Collapse
Affiliation(s)
- Mina Ushiyama
- Department of Pharmacology, Graduate School of Medical and Dental Sciences, Kagoshima University, Sakuragaoka, Kagoshima, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Dorsam ST, Vomhof-Dekrey E, Hermann RJ, Haring JS, Van der Steen T, Wilkerson E, Boskovic G, Denvir J, Dementieva Y, Primerano D, Dorsam GP. Identification of the early VIP-regulated transcriptome and its associated, interactome in resting and activated murine CD4 T cells. Mol Immunol 2010; 47:1181-94. [PMID: 20117839 DOI: 10.1016/j.molimm.2010.01.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 12/15/2009] [Accepted: 01/05/2010] [Indexed: 01/12/2023]
Abstract
More than 40 years after the discovery of vasoactive intestinal peptide (VIP), its transcriptome in the immune system has still not been completely elucidated. In an attempt to understand the biological role of this neuropeptide in immunity, we chose CD4 T cells as a cellular system. Agilent Mouse Whole Genome microarrays were hybridized with fluorescently labeled total RNA isolated from resting CD4 T cells cultured +/-10(-7)M VIP for 5h or PMA/ionomycin activated CD4 T cells cultured +/-10(-7)M VIP for 5h. These VIP-regulated transcriptomes were analyzed by Significance Analysis of Microarrays (SAM) and Ingenuity Pathway Analysis (IPA) software to identify relevant signaling pathways modulated by VIP in the absence and presence of T cell activation. In resting CD4 T cells, VIP-modulated 368 genes, ranging from 3.49 to -4.78-fold. In the PMA/ionomycin activated CD4 T cells, 326 gene expression levels were changed by VIP, ranging from 2.94 to -1.66-fold. IPA analysis revealed that VIP exposure alters cellular function through EGFR signaling in resting CD4 T cells, and modulates immediate early genes, Fos and CREM/ICER, in activated CD4 T cells. These gene expression changes are suggested to explain at a molecular level how VIP can regulate T cell homing to the gut and induce regulatory T cell generation.
Collapse
Affiliation(s)
- Sheri Tinnell Dorsam
- Department of Chemistry and Molecular Biology, North Dakota State University, Fargo, ND 58108-6050, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Vaudry D, Falluel-Morel A, Bourgault S, Basille M, Burel D, Wurtz O, Fournier A, Chow BKC, Hashimoto H, Galas L, Vaudry H. Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery. Pharmacol Rev 2009; 61:283-357. [DOI: 10.1124/pr.109.001370] [Citation(s) in RCA: 829] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
|
47
|
Körner M, Miller LJ. Alternative splicing of pre-mRNA in cancer: focus on G protein-coupled peptide hormone receptors. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 175:461-72. [PMID: 19574427 DOI: 10.2353/ajpath.2009.081135] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Through alternative splicing, multiple different transcripts can be generated from a single gene. Alternative splicing represents an important molecular mechanism of gene regulation in physiological processes such as developmental programming as well as in disease. In cancer, splicing is significantly altered. Tumors express a different collection of alternative spliceoforms than normal tissues. Many tumor-associated splice variants arise from genes with an established role in carcinogenesis or tumor progression, and their functions can be oncogenic. This raises the possibility that products of alternative splicing play a pathogenic role in cancer. Moreover, cancer-associated spliceoforms represent potential diagnostic biomarkers and therapeutic targets. G protein-coupled peptide hormone receptors provide a good illustration of alternative splicing in cancer. The wild-type forms of these receptors have long been known to be expressed in cancer and to modulate tumor cell functions. They are also recognized as attractive clinical targets. Recently, splice variants of these receptors have been increasingly identified in various types of cancer. In particular, alternative cholecystokinin type 2, secretin, and growth hormone-releasing hormone receptor spliceoforms are expressed in tumors. Peptide hormone receptor splice variants can fundamentally differ from their wild-type receptor counterparts in pharmacological and functional characteristics, in their distribution in normal and malignant tissues, and in their potential use for clinical applications.
Collapse
Affiliation(s)
- Meike Körner
- Institute of Pathology of the University of Berne, Murtenstrasse 31, CH-3010 Berne, Switzerland.
| | | |
Collapse
|
48
|
Gericke MT, Kosacka J, Koch D, Nowicki M, Schröder T, Ricken AM, Nieber K, Spanel-Borowski K. Receptors for NPY and PACAP differ in expression and activity during adipogenesis in the murine 3T3-L1 fibroblast cell line. Br J Pharmacol 2009; 157:620-32. [PMID: 19422400 DOI: 10.1111/j.1476-5381.2009.00164.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Neuropeptides are involved in the regulation of food intake in the central nervous system, but they might also act on peripheral fat tissue via neuropeptide receptors. EXPERIMENTAL APPROACH We investigated the receptor expression and activity of pituitary adenylate cyclase-activating polypeptide (PACAP) and of neuropeptide Y at the mRNA and protein levels in the 3T3-L1 fibroblast line during differentiation into adipocytes. Intracellular calcium concentration was measured by calcium imaging. KEY RESULTS The PACAP receptors PAC(1) and VPAC(2) as well as the neuropeptide Y(1) receptor were expressed at the mRNA level in fibroblasts, pre-adipocytes and adipocytes. The mRNA profile of the PAC(1) receptor isoforms showed the HOP sequence, whereas the HIP-isoform was present in subconfluent 3T3-L1 fibroblasts only. At the protein level, the mature 3T3-L1 adipocytes produced the PAC(1) and Y(1) receptors; only the PAC(1) receptor showed carbohydrate residues. Both neuropeptides induced an increase of intracellular calcium in mature adipocytes, which was absent in the precursor cells. These changes in calcium were mediated by Y(1) and PAC(1) receptors as demonstrated by the effects of specific receptor agonists and antagonists. CONCLUSIONS AND IMPLICATIONS As the PAC(1)-HOP receptor variant seems to be responsible for PACAP-mediated calcium influx in many cell types, the HOP sequence might also mediate the increase in intracellular calcium in adipocytes. Because a high intracellular calcium level is associated with lipogenesis, peptidergic innervation of adipose tissue might be involved in stress-induced obesity.
Collapse
|
49
|
Dickson L, Finlayson K. VPAC and PAC receptors: From ligands to function. Pharmacol Ther 2008; 121:294-316. [PMID: 19109992 DOI: 10.1016/j.pharmthera.2008.11.006] [Citation(s) in RCA: 273] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Accepted: 11/18/2008] [Indexed: 02/03/2023]
Abstract
Vasoactive intestinal peptide (VIP) and the pituitary adenylate cyclase activating polypeptides (PACAPs) share 68% identity at the amino acid level and belong to the secretin peptide family. Following the initial discovery of VIP almost four decades ago a substantial amount of knowledge has been presented describing the mechanisms of action, distribution and pleiotropic functions of these related peptides. It is now known that the physiological actions of these widely distributed peptides are produced through activation of three common G-protein coupled receptors (VPAC(1), VPAC(2) and PAC(1)R) which preferentially stimulate adenylate cyclase and increase intracellular cAMP, although stimulation of other intracellular messengers, including calcium and phospholipase D, has been reported. Using a range of in vitro and in vivo approaches, including cell-based functional assays, transgenic animals and rodent models of disease, VPAC/PAC receptor activation has been associated with numerous physiological processes (e.g. control of circadian rhythms) and clinical conditions (e.g. pulmonary hypertension), which underlies on-going research efforts and makes these peptides and their cognate receptors attractive targets for the pharmaceutical industry. However, despite the considerable interest in VPAC/PAC receptors and the processes which they mediate, there is still a paucity of selective and available, non-peptide ligands, which has hindered further advances in this field both at the basic research and clinical level. This review summarises the current knowledge of VIP/PACAP and the VPAC/PAC receptors with regard to their distribution, pharmacology, signalling pathways, splice variants and finally, the utility of animal models in exploring their physiological roles.
Collapse
Affiliation(s)
- Louise Dickson
- Centre for Integrative Physiology, University of Edinburgh, EH8 9XD, UK
| | | |
Collapse
|
50
|
Wang J, Wang Y, Li X, Li J, Leung F. Cloning, Tissue Distribution, and Functional Characterization of Chicken Glucagon Receptor. Poult Sci 2008; 87:2678-88. [DOI: 10.3382/ps.2008-00260] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|