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Vasoactive intestinal peptide blockade suppresses tumor growth by regulating macrophage polarization and function in CT26 tumor-bearing mice. Sci Rep 2023; 13:927. [PMID: 36650220 PMCID: PMC9845384 DOI: 10.1038/s41598-023-28073-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 01/12/2023] [Indexed: 01/19/2023] Open
Abstract
Macrophages are a major population of immune cells in solid cancers, especially colorectal cancers. Tumor-associated macrophages (TAMs) are commonly divided into M1-like (tumor suppression) and M2-like (tumor promotion) phenotypes. Vasoactive intestinal peptide (VIP) is an immunoregulatory neuropeptide with a potent anti-inflammatory function. Inhibition of VIP signaling has been shown to increase CD8+ T cell proliferation and function in viral infection and lymphoma. However, the role of VIP in macrophage polarization and function in solid tumors remains unknown. Here, we demonstrated that conditioned medium from CT26 (CT26-CM) cells enhanced M2-related marker and VIP receptor (VPAC) gene expression in RAW264.7 macrophages. VIP hybrid, a VIP antagonist, enhanced M1-related genes but reduced Mrc1 gene expression and increased phagocytic ability in CT26-CM-treated RAW264.7 cells. In immunodeficient SCID mice, VIP antagonist alone or in combination with anti-PD-1 antibody attenuated CT26 tumor growth compared with the control. Analysis of tumor-infiltrating leukocytes found that VIP antagonist increased M1/M2 ratios and macrophage phagocytosis of CT26-GFP cells. Furthermore, Vipr2 gene silencing or VPAC2 activation affected the polarization of CT26-CM-treated RAW264.7 cells. In conclusion, the inhibition of VIP signaling enhanced M1 macrophage polarization and macrophage phagocytic function, resulting in tumor regression in a CT26 colon cancer model.
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2
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Charron CL, Hickey JL, Nsiama TK, Cruickshank DR, Turnbull WL, Luyt LG. Molecular imaging probes derived from natural peptides. Nat Prod Rep 2017; 33:761-800. [PMID: 26911790 DOI: 10.1039/c5np00083a] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Covering: up to the end of 2015.Peptides are naturally occurring compounds that play an important role in all living systems and are responsible for a range of essential functions. Peptide receptors have been implicated in disease states such as oncology, metabolic disorders and cardiovascular disease. Therefore, natural peptides have been exploited as diagnostic and therapeutic agents due to the unique target specificity for their endogenous receptors. This review discusses a variety of natural peptides highlighting their discovery, endogenous receptors, as well as their derivatization to create molecular imaging agents, with an emphasis on the design of radiolabelled peptides. This review also highlights methods for discovering new and novel peptides when knowledge of specific targets and endogenous ligands are not available.
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Affiliation(s)
- C L Charron
- Department of Chemistry, The University of Western Ontario, London, Canada.
| | - J L Hickey
- Department of Chemistry, The University of Western Ontario, London, Canada.
| | - T K Nsiama
- London Regional Cancer Program, Lawson Health Research Institute, London, Canada
| | - D R Cruickshank
- Department of Chemistry, The University of Western Ontario, London, Canada.
| | - W L Turnbull
- Department of Chemistry, The University of Western Ontario, London, Canada.
| | - L G Luyt
- Department of Chemistry, The University of Western Ontario, London, Canada. and Departments of Oncology and Medical Imaging, The University of Western Ontario, London, Canada and London Regional Cancer Program, Lawson Health Research Institute, London, Canada
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3
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Hacohen Kleiman G, Barnea A, Gozes I. ADNP: A major autism mutated gene is differentially distributed (age and gender) in the songbird brain. Peptides 2015; 72:75-9. [PMID: 25895853 DOI: 10.1016/j.peptides.2015.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 04/03/2015] [Accepted: 04/04/2015] [Indexed: 11/25/2022]
Abstract
ADNP is a protein necessary for brain development, important for brain plasticity, cognitive and social functioning, characteristics that are all impaired in autism and in the Adnp(+/-) mouse model, in a sex-dependent manner. ADNP was originally discovered as a protein that is secreted from glial cells in response to vasoactive intestinal peptide (VIP). VIP is a major neuroprotective peptide in the CNS and PNS and was also associated with social recognition in rodents and aggression, pair-bonding and parental behaviors in birds. Comparative sequence alignment revealed high evolutionary conservation of ADNP in Chordata. Despite its importance in brain function, ADNP has never been studied in birds. Zebra finches (Taeniopygia guttata) are highly social songbirds that have a sexually dichotomous anatomical brain structure, with males demonstrating a developed song system, presenting a model to study behavior and potential sexually dependent fundamental differences. Here, using quantitative real time polymerase chain reaction (qRT-PCR), we discovered sexually dichotomous and age related differences in ADNP mRNA expression in three different regions of the song bird brain-cerebellum, cerebrum, and brain stem. Higher levels of ADNP mRNA were specifically found in young male compared to the female cerebrum, while aging caused a significant 2 and 3-fold decrease in the female and male cerebrum, respectively. Furthermore, a comparison between the three tested brain regions revealed unique sex-dependent ADNP mRNA distribution patterns, affected by aging. Future studies are aimed at deciphering the function of ADNP in birds, toward a better molecular understanding of sexual dichotomy in singing behavior in birds.
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Affiliation(s)
- Gal Hacohen Kleiman
- Department of Human Molecular Genetics and Biochemistry, Sackler Medical School, Adams Super Center for Brain Studies & Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel; Department of Natural and Life Sciences, The Open University, Raanana, Israel
| | - Anat Barnea
- Department of Natural and Life Sciences, The Open University, Raanana, Israel
| | - Illana Gozes
- Department of Human Molecular Genetics and Biochemistry, Sackler Medical School, Adams Super Center for Brain Studies & Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel.
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4
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Pal K, Mukhopadhyay S. Primary cilium and sonic hedgehog signaling during neural tube patterning: Role of GPCRs and second messengers. Dev Neurobiol 2014; 75:337-48. [DOI: 10.1002/dneu.22193] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/09/2014] [Accepted: 05/22/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Kasturi Pal
- Department of Cell Biology; UT Southwestern Medical Center; Dallas Texas 75390
| | - Saikat Mukhopadhyay
- Department of Cell Biology; UT Southwestern Medical Center; Dallas Texas 75390
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5
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Argiolas A, Melis MR. Neuropeptides and central control of sexual behaviour from the past to the present: a review. Prog Neurobiol 2013; 108:80-107. [PMID: 23851261 DOI: 10.1016/j.pneurobio.2013.06.006] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 06/28/2013] [Accepted: 06/29/2013] [Indexed: 12/23/2022]
Abstract
Of the numerous neuropeptides identified in the central nervous system, only a few are involved in the control of sexual behaviour. Among these, the most studied are oxytocin, adrenocorticotropin, α-melanocyte stimulating hormone and opioid peptides. While opioid peptides inhibit sexual performance, the others facilitate sexual behaviour in most of the species studied so far (rats, mice, monkeys and humans). However, evidence for a sexual role of gonadotropin-releasing hormone, corticotropin releasing factor, neuropeptide Y, galanin and galanin-like peptide, cholecystokinin, substance P, vasoactive intestinal peptide, vasopressin, angiotensin II, hypocretins/orexins and VGF-derived peptides are also available. Corticotropin releasing factor, neuropeptide Y, cholecystokinin, vasopressin and angiotensin II inhibit, while substance P, vasoactive intestinal peptide, hypocretins/orexins and some VGF-derived peptide facilitate sexual behaviour. Neuropeptides influence sexual behaviour by acting mainly in the hypothalamic nuclei (i.e., lateral hypothalamus, paraventricular nucleus, ventromedial nucleus, arcuate nucleus), in the medial preoptic area and in the spinal cord. However, it is often unclear whether neuropeptides influence the anticipatory phase (sexual arousal and/or motivation) or the consummatory phase (performance) of sexual behaviour, except in a few cases (e.g., opioid peptides and oxytocin). Unfortunately, scarce information has been added in the last 15 years on the neural mechanisms by which neuropeptides influence sexual behaviour, most studied neuropeptides apart. This may be due to a decreased interest of researchers on neuropeptides and sexual behaviour or on sexual behaviour in general. Such a decrease may be related to the discovery of orally effective, locally acting type V phosphodiesterase inhibitors for the therapy of erectile dysfunction.
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Affiliation(s)
- Antonio Argiolas
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.
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6
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Pharmacological inhibition of VIP signaling enhances antiviral immunity and improves survival in murine cytomegalovirus-infected allogeneic bone marrow transplant recipients. Blood 2013; 121:2347-51. [PMID: 23325838 DOI: 10.1182/blood-2012-06-437640] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cytomegalovirus (CMV) infection following allogeneic bone marrow transplant (allo-BMT) is controlled by donor-derived cellular immunity. Vasoactive intestinal peptide (VIP) suppresses Th1 immunity. We hypothesized that blocking VIP-signaling would enhance anti-CMV immunity in murine recipients of allo-BMT. Recipients were transplanted with bone marrow (BM) and T-cells from major histocompatibility complex (MHC)-mismatched VIP-knockout (KO) or wild-type donors, and treated with 7 daily subcutaneous injections of VIPhyb (peptidic VIP-antagonist) or phosphate-buffered saline (PBS). Genetic and pharmacological blockade of VIP-signaling protected allo-BMT recipients from lethal murine CMV (mCMV) infection, improving survival without increasing graft-versus-host disease. Mice treated with VIPhyb or transplanted with VIP-KO allografts had significantly lower viral loads, increased numbers of mCMV-M45-peptide-MHC-tetramer(+) CD8(+) T-cells, with lower PD-1 expression, and enhanced primary and secondary cellular immune responses after mCMV infection than did PBS-treated mice. These results demonstrate that administration of a VIP antagonist after allo-BMT is a promising safely therapeutic approach to enhance antiviral cellular immunity.
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7
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Abstract
The importance of adult neurogenesis has only recently been accepted, resulting in a completely new field of investigation within stem cell biology. The regulation and functional significance of adult neurogenesis is currently an area of highly active research. G-protein-coupled receptors (GPCRs) have emerged as potential modulators of adult neurogenesis. GPCRs represent a class of proteins with significant clinical importance, because approximately 30% of all modern therapeutic treatments target these receptors. GPCRs bind to a large class of neurotransmitters and neuromodulators such as norepinephrine, dopamine, and serotonin. Besides their typical role in cellular communication, GPCRs are expressed on adult neural stem cells and their progenitors that relay specific signals to regulate the neurogenic process. This review summarizes the field of adult neurogenesis and its methods and specifies the roles of various GPCRs and their signal transduction pathways that are involved in the regulation of adult neural stem cells and their progenitors. Current evidence supporting adult neurogenesis as a model for self-repair in neuropathologic conditions, adult neural stem cell therapeutic strategies, and potential avenues for GPCR-based therapeutics are also discussed.
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Affiliation(s)
- Van A Doze
- Department of Molecular Cardiology, NB50, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195, USA
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8
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Zaben M, John Sheward W, Shtaya A, Abbosh C, Harmar AJ, Pringle AK, Gray WP. The Neurotransmitter VIP Expands the Pool of Symmetrically Dividing Postnatal Dentate Gyrus Precursors via VPAC2Receptors or Directs Them Toward a Neuronal Fate via VPAC1receptors. Stem Cells 2009; 27:2539-51. [DOI: 10.1002/stem.184] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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9
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VIP, from gene to behavior and back: summarizing my 25 years of research. J Mol Neurosci 2008; 36:115-24. [PMID: 18607776 DOI: 10.1007/s12031-008-9105-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Accepted: 05/15/2008] [Indexed: 11/25/2022]
Abstract
Vasoactive intestinal peptide (VIP) is an interesting example of a 28-amino acid neuropeptide that is abundantly expressed in discrete brain regions/neurons and hence may contribute to brain function. This short review summarizes my own point of view and encompasses 25 years of work and over 100 publications targeting the understanding of VIP production and biological activity. The review starts with our original cloning of the VIP gene, it then continues to discoveries of regulation of VIP synthesis and the establishment of the first VIP transgenic mice. The review ends with the identification of novel VIP analogs that helped decipher VIP's important role during development, in regulation of the biological clock(s) and diurnal rhythms, sexual activity, learning and memory as well as social behavior, and cancer. This review cites only articles that I have coauthored and gives my own perspective of this exciting ever-growing field.
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10
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Sigalet DL, Wallace LE, Holst JJ, Martin GR, Kaji T, Tanaka H, Sharkey KA. Enteric neural pathways mediate the anti-inflammatory actions of glucagon-like peptide 2. Am J Physiol Gastrointest Liver Physiol 2007; 293:G211-21. [PMID: 17395898 DOI: 10.1152/ajpgi.00530.2006] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glucagon-like peptide-2 (GLP-2) is an important regulator of nutritional absorptive capacity with anti-inflammatory actions. We hypothesized that GLP-2 reduces intestinal mucosal inflammation by activation of vasoactive intestinal polypeptide (VIP) neurons of the submucosal plexus. Ileitis or colitis was induced in rats by injection of trinitrobenzene sulfonic acid (TNBS), or colitis was induced by administration of dextran sodium sulfate (DSS) in drinking water. Subsets of animals received (1-33)-GLP-2 (50 mug/kg sc bid) either immediately or 2 days after the establishment of inflammation and were followed for 3-5 days. The involvement of VIP neurons was assessed by concomitant administration of GLP-2 and the VIP antagonist [Lys(1)-Pro(2,5)-Arg(3,4)-Tyr(6)]VIP and by immunohistochemical labeling of GLP-2-activated neurons. In all models, GLP-2 treatment, whether given immediately or delayed until inflammation was established, resulted in significant improvements in animal weights, mucosal inflammation indices (myeloperoxidase levels, histological mucosal scores), and reduced levels of inflammatory cytokines (IFN-gamma, TNF-alpha, IL-1beta) and inducible nitric oxide synthase, with increased levels of IL-10 in TNBS ileitis and DSS colitis. Reduced rates of crypt cell proliferation and of apoptosis within crypts in inflamed tissues were also noted with GLP-2 treatment. These effects were abolished with coadministration of GLP-2 and the VIP antagonist. GLP-2 was shown to activate neurons and to increase the number of cells expressing VIP in the submucosal plexus of the ileum. These findings suggest that GLP-2 acts as an anti-inflammatory agent through activation of enteric VIP neurons, independent of proliferative effects. They support further studies to examine the role of neural signaling in the regulation of intestinal inflammation.
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Affiliation(s)
- David L Sigalet
- Gastrointestinal Research Group, Institute of Infection, Immunity, and Inflammation, Faculty of Medicine, University of Calgary, Health Science Centre, 3330 Hospital Drive NW, Calgary, Alberta, Canada.
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11
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Gozes I, Furman S. Clinical endocrinology and metabolism. Potential clinical applications of vasoactive intestinal peptide: a selected update. Best Pract Res Clin Endocrinol Metab 2004; 18:623-40. [PMID: 15533779 DOI: 10.1016/j.beem.2004.08.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Neuropeptides are expressed in neurons innervating endocrine cells or in endocrine cells and cancer cells, and are released on site to act as hormones and growth factors. Vasoactive intestinal peptide (VIP) was first discovered in the early 1970s and has since become the area of research for many laboratories. VIP has a neuroendocrine role as it is intimately involved with the synthesis, secretion and action of other neuroendocrine hormones as well as cytokines and chemokines. Major outcomes of VIP downregulation encompass developmental and behavioral dysfunctions, including impaired diurnal rhythms. Overexpression of VIP has been associated with diarrhea and cancer, and overexpression of VIP receptors is associated with cancerous growth. This short review outlines some of the recent progress made in VIP research.
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Affiliation(s)
- Illana Gozes
- Department of Clinical Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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12
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Dufes C, Alleaume C, Montoni A, Olivier JC, Muller JM. Effects of the vasoactive intestinal peptide (VIP) and related peptides on glioblastoma cell growth in vitro. J Mol Neurosci 2004; 21:91-102. [PMID: 14593209 DOI: 10.1385/jmn:21:2:91] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2003] [Accepted: 03/29/2003] [Indexed: 11/11/2022]
Abstract
The growth rate of numerous cancer cell lines is regulated in part by actions of neuropeptides of the vasoactive intestinal peptide (VIP) family, which also includes pituitary adenylate cyclase-activating peptide (PACAP), glucagon, and peptide histidine/isoleucine (PHI). The aim of this work was to investigate the effect of these peptides on the growth of the rat glioblastoma cell line C6 in vitro. We also sought to determine which binding sites were correlated with the effects observed. Proliferation studies performed by means of a CyQuant trade mark assay showed that VIP and PACAP strongly stimulated C6 cell proliferation at most of the concentrations tested, whereas PHI increased cell proliferation only when associated with VIP. Two growth hormone-releasing factor (GRF) derivatives and the VIP antagonist hybrid peptide neurotensin-VIP were able to inhibit VIP-induced cell growth stimulation, even at very low concentrations. Binding experiments carried out on intact cultured C6 cells, using 125I-labeled VIP and PACAP as tracers, revealed that the effects of the peptides on cell growth were correlated with the expression on C6 cells of polyvalent high-affinity VIP-PACAP binding sites and of a second subtype corresponding to very high-affinity VIP-selective binding species. The latter subtype, which interacted poorly with PACAP with a 10,000-fold lower affinity than VIP, might mediate the antagonist effects of neurotensin- VIP and of both GRF derivatives on VIP-induced cell growth stimulation.
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Affiliation(s)
- Christine Dufes
- Laboratoire de Biologie des Interactions Cellulaires, CNRS UMR 6558, Faculté de Sciences, Université de Poitiers, 86022 Poitiers, France
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13
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Zawilska JB, Niewiadomski P, Nowak JZ. Characterization of vasoactive intestinal peptide/pituitary adenylate cyclase-activating polypeptide receptors in chick cerebral cortex. J Mol Neurosci 2003; 20:153-62. [PMID: 12794309 DOI: 10.1385/jmn:20:2:153] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2002] [Accepted: 12/08/2002] [Indexed: 11/11/2022]
Abstract
In this study receptors for vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) were characterized in chick cerebral cortex by an in vitro binding technique, using 125I-labeled VIP ([125I]-VIP) as a ligand. The specific binding of [125I]-VIP to chick cerebral cortical membranes was found to be rapid, stable, saturable, reversible, and of high affinity. Saturation analysis resulted in a linear Scatchard plot, suggesting binding to a single class of receptor binding sites with high affinity (Kd = 0.21 nM) and low capacity (Bmax = 19.5 fmol/mg protein). The relative rank order of potency of the tested peptides to inhibit [125I]-VIP binding to chick cerebrum was VIP (chicken) > or = VIP (mammalian) > or = PACAP27 > or = PACAP38 >> VIP6-28 (mammalian) > PHI (porcine) >> neurotensin6-11-chicken VIP7-28 > neurotensin6-11-mammalian VIP7-28 >>> VIP16-28 (chicken; inactive) approximately secretin (inactive). About 60% of [125I]-VIP-binding sites in chick cerebral cortex were sensitive to Gpp(NH)p, a nonhydrolyzable analog of GTP. It has been concluded that the cerebral cortex of chick, in addition to PAC1 receptors, contains a population of VPAC-type receptors.
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MESH Headings
- Animals
- Binding, Competitive/drug effects
- Binding, Competitive/physiology
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Cerebral Cortex/drug effects
- Cerebral Cortex/metabolism
- Chickens/metabolism
- Guanylyl Imidodiphosphate/pharmacology
- Iodine Radioisotopes
- Male
- Neurons/drug effects
- Neurons/metabolism
- Neuropeptides/metabolism
- Pituitary Adenylate Cyclase-Activating Polypeptide
- Radioligand Assay
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
- Receptors, Pituitary Hormone/drug effects
- Receptors, Pituitary Hormone/metabolism
- Receptors, Vasoactive Intestinal Peptide/drug effects
- Receptors, Vasoactive Intestinal Peptide/metabolism
- Receptors, Vasoactive Intestinal Polypeptide, Type I
- Subcellular Fractions
- Vasoactive Intestinal Peptide/metabolism
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Affiliation(s)
- Jolanta B Zawilska
- Department of Biogenic Amines, Polish Academy of Sciences, P-225, 90-950 Lodz, Poland.
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14
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Levy A, Gal R, Granoth R, Dreznik Z, Fridkin M, Gozes I. In vitro and in vivo treatment of colon cancer by VIP antagonists. REGULATORY PEPTIDES 2002; 109:127-33. [PMID: 12409224 DOI: 10.1016/s0167-0115(02)00195-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Vasoactive intestinal peptide (VIP) is secreted from many cancer lines and VIP binding was observed in many tumors. We have shown before that VIP antagonists are potent inhibitors of neoplastic growth of neuroblastoma, lung and breast cancer cells in vitro. Here, the cultured colon cancer cell line HCT-15 that exhibited VIP receptor expression was treated with the VIP hybrid antagonist neurotensin(6-11)VIP(7-28). The antineoplastic activity was assessed by thymidine incorporation. Neurotensin(6-11)VIP(7-28) efficiently inhibited cancer growth with a maximal effect at nanomolar concentrations. Once the inhibitory properties of the VIP antagonist on colon cancer cells were established, the in vivo curative effects were analyzed. Sprague-Dawley rats were injected with azoxymethane (AOM) (15 mg/kg/week) for 2 weeks, providing artificial induction of colon tumors. The rats were then allocated into four experimental groups: (1) receiving no treatment; (2) receiving treatment with saline; (3, 4) receiving treatment with 10 or 20 microg of neurotensin(6-11)VIP(7-28), respectively. After 10 weeks of daily injections, rats were sacrificed and tumors assessed for stage, volume, location, differentiation and lymphocytic infiltrate. Embedded mucosa was assessed for dysplastic crypts. Results showed that the antagonist treatment reduced the tumor volume, staging, lymphocyte infiltrate and the number of dysplastic crypts. Thus, neurotensin(6-11)VIP(7-28) could serve as an effective cancer treatment and a preventing agent.
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Affiliation(s)
- Albert Levy
- Department of Clinical Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Israel
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15
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Abstract
Many neuropeptides are involved in the control of sexual behaviour at the central level. Among these, the most studied are adrenocorticotropin, alpha-melanocyte stimulating hormone, oxytocin and opioid peptides. This attempt to review old and new neuropharmacological, biochemical and psychobiological studies in this field, shows that all these neuropeptides apparently facilitate sexual behaviour, except for opioid peptides, which inhibit sexual performance, in most of the species studied so far (rats, mice, monkeys and humans). However, gonadotropin-releasing hormone, corticotropin releasing factor, neuropeptide Y, galanin, cholecystokinin, substance P and vasoactive intestinal peptide may be also involved in the control of sexual behaviour. Apparently, corticotropin releasing factor, neuropeptide Y and cholecystokinin inhibit, while substance P and vasoactive intestinal peptide facilitate, sexual behaviour. In contrast, gonadotropin-releasing hormone has been reported to exert a facilitative, inhibitory or no effect at all on sexual behaviour. Galanin was also shown either to facilitate or inhibit sexual behaviour. The above-mentioned putative role of the neuropeptides in sexual behaviour derives mainly from studies done in rats. In these studies, neuropeptides, their antisera or drugs that act as agonists or antagonists of neuropeptide receptors, were tested for their effect on sexual behaviour after systemic, intracerebroventricular, or intracerebral administration. The latter were infused into brain areas relevant for sexual behaviour, such as the medial preoptic area, and the ventromedial and paraventricular nuclei of the hypothalamus. The above studies show that little information is available on the mechanisms by which neuropeptides influence sexual behaviour. Also unclear is whether the above neuropeptides influence the anticipatory phase (sexual arousal and/or motivation) or the consummatory phase (performance) of sexual behaviour, except for opioid peptides. New information about the role of neuropeptides may come from the application of molecular biology and genetic manipulation techniques to the study of sexual behaviour. Of these, FOS protein determination, antisense oligonucleotides aimed at the neutralisation of neuropeptide and/or neuropeptide receptor mRNAs in specific brain areas, and gene ablation seem the most promising. Although still in the early stages, it is likely that these methodologies will provide new insights into the role of neuropeptides in the control of sexual behaviour.
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Affiliation(s)
- A Argiolas
- Bernard B. Brodie Department of Neuroscience and Centre for Neuropharmacology, National Research Council, Cagliari, Italy.
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16
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Gozes I, Perl O, Zamostiano R, Rubinraut S, Fridkin M, Shochat L, Lewin LM. Multiple actions of a hybrid PACAP antagonist: neuronal cell killing and inhibition of sperm motility. Ann N Y Acad Sci 1998; 865:266-73. [PMID: 9928021 DOI: 10.1111/j.1749-6632.1998.tb11187.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pituitary stimulating adenylate cyclase (PACAP) is a major regulatory peptide with two active molecular forms: PACAP-27 and PACAP-38. Both molecular forms promote neuronal survival and protect against neurotoxicity. Based on our previous hybrid peptide strategy in designing vasoactive intestinal peptide (VIP) antagonists, novel PACAP analogues were synthesized (neurotensin6-11 PACAP7-27 and neurotensin6-11 PACAP7-38). In addition to the hybrid modification, the methionine in position 17 was replaced by norleucine (Nle). Treatment of rat cerebral cortical cultures for five days with the putative PACAP antagonists (1 nM) resulted in a 35-45% reduction in neuronal cell counts as compared to controls. Neuronal cell death was already obtained at picomolar concentrations for the neurotensin6-11 PACAP7-27 antagonist with 70% death at 10(-8) M. Co-administration of the PACAP hybrid analogue with picomolar amounts of PACAP-27 or Nle17-PACAP-27 attenuated the reduction in neuronal cell counts. While the protective effects of both analogues exhibited a peak at 1 pM concentrations, the Nle-containing agonist displayed a broader range of active concentrations (10(-12)M-10(-9) M). The putative PACAP antagonist also inhibited sperm motility (golden hamster) in a dose-dependent manner as assessed in vitro. Complete inhibition was observed at 10 microM, suggesting a role for PACAP in sperm motility and sexual function. Thus, previous findings of a large number of PACAP and PACAP receptors in the nervous system and the reproductive system are now correlated with a function in neuronal survival and sperm motility. The structure-activity studies suggest that the methionine in position 17 and the first six amino acids are important in the determination of PACAP activity, knowledge that may facilitate PACAP-based drug design.
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Affiliation(s)
- I Gozes
- Department of Clinical Biochemistry, Sackler School of Medicine, Tel Aviv University, Israel.
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17
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Abstract
Vasoactive intestinal peptide (VIP) is a 28-amino acid neuropeptide with potent growth-related actions on dissociated neural cells. In recent years its role in brain development has been elucidated: VIP has been shown to be a regulator of early neurodevelopment and embryonic growth, a stimulator of neocortical astrocytogenesis and a neuroprotective molecule against excitotoxic and other neurotoxic substances. Thus VIP appears as a fundamental regulator of brain growth and development, and a potent neuroprotective agent, possibly involved in pathological processes such as microcephalies and some neurological impairments observed in very premature babies. Similarly, VIP and VIP derivatives could represent a new avenue in the search of therapeutics for excitotoxic lesions of the developing brain.
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Affiliation(s)
- P Gressens
- Service de neurologie pédiatrique et Inserm CRI 97-01, Hôpital Robert-Debré, Paris, France
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Abstract
The present review is dedicated to the work of B.S. Mc Ewen on the regulatory effects of steroid hormones on peptidergic neurotransmission in the brain and pituitary. The focus is on the discoveries encompassing almost two decades of work on the central and neuroendocrine regulation of vasoactive intestinal peptide (VIP) by both corticosteroids and estrogens.
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Cooke HJ, Sidhu M, Wang YZ. Activation of 5-HT1P receptors on submucosal afferents subsequently triggers VIP neurons and chloride secretion in the guinea-pig colon. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1997; 66:105-10. [PMID: 9335000 DOI: 10.1016/s0165-1838(97)00075-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The role of vasoactive intestinal peptide (VIP) was investigated when mucosal stroking and 5-hydroxytryptamine (5-HT) were used to activate neural reflexes that stimulate chloride secretion in the guinea pig colon. Muscle-stripped segments of colon containing intact submucosal ganglia without myenteric ganglia were set up in modified flux chambers in order to record short-circuit current (Isc). Mucosal stroking with a brush for 1 s or a pulse of 5-HT (injection of 15 microliters of 100 microM 5-HT into 1.5 ml of mucosal solution) caused an increase in Isc that was reduced by the VIP antagonist, neurotensin6-11-VIP7-28, in a concentration-dependent manner. The Isc responses to mucosal stroking and a 5-HT pulse were reduced by 53% and 58%, respectively, by 2 microM neurotensin6-11-VIP7-28. The residual Isc response in the presence of neurotensin6-11-VIP7-28 was abolished by atropine. Blockade of 5-HT1P receptors on submucosal afferent neurons decreased Isc responses to stroking or a 5-HT pulse. The residual Isc response after 5-HT1P receptors were blocked was reduced by only 11-14% by neurotensin6-11-VIP7-28. In the presence of blockade of both 5-HT1P and VIP receptors, atropine abolished the Isc response to both stimuli. The observations suggest that the neural circuitry activated by stroking includes at least two independent pathways. One pathway contains VIP neurons which receive inputs directly or indirectly from 5-HT1P receptor-containing afferents. A second pathway involves muscarinic cholinergic transmission that is independent of 5-HT1P and VIP receptor activation.
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Affiliation(s)
- H J Cooke
- Department of Pharmacology, Ohio State University, Columbus 43210, USA.
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Gozes I, Bachar M, Bardea A, Davidson A, Rubinraut S, Fridkin M, Giladi E. Protection against developmental retardation in apolipoprotein E-deficient mice by a fatty neuropeptide: implications for early treatment of Alzheimer's disease. JOURNAL OF NEUROBIOLOGY 1997; 33:329-42. [PMID: 9298769 DOI: 10.1002/(sici)1097-4695(199709)33:3<329::aid-neu10>3.0.co;2-a] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Stearyl-Nle17-VIP (SNV) is a novel agonist of vasoactive intestinal peptide (VIP) exhibiting a 100-fold greater potency than the parent molecule and specificity for a receptor associated with neuronal survival. Here, mice deficient in apolipoprotein E (ApoE), a molecule associated with the etiology of Alzheimer's disease, served as a model to investigate the developmental and protective effects of SNV. In comparison to control animals, the deficient mice exhibited (a) reduced amounts of VIP messenger RNA; (b) decreased cholinergic activity (c) significant retardation in the acquisition of developmental milestones: forelimb placing behavior and cliff avoidance behavior; and (d) learning and memory impairments. Daily injections of SNV to ApoE-deficient newborn pups resulted in increased cholinergic activity and marked improvements in the time of acquisition of behavioral milestones, with peptide-treated animals developing as fast as control animals and exhibiting improved cognitive functions after cessation of peptide treatment. Specificity was demonstrated in that treatment with a related peptide (PACAP), pituitary adenylate cyclase-activating peptide, produced only limited amelioration. As certain genotypes of ApoE increase the probability of Alzheimer's disease, early counseling and preventive treatments may now offer an important route for therapeutics design.
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Affiliation(s)
- I Gozes
- Department of Clinical Biochemistry, Sackler Medical School, Tel Aviv University, Israel
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