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Scavello F, Amiche M, Ghia JE. The Editorial Position on 'Recent Advances in Multifunctional Antimicrobial Peptides as Preclinical Therapeutic Studies and Clinical Future Applications'. Pharmaceutics 2023; 15:2383. [PMID: 37896143 PMCID: PMC10609690 DOI: 10.3390/pharmaceutics15102383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 09/16/2023] [Indexed: 10/29/2023] Open
Abstract
Antibiotic resistance has recently been recognized as an alarming issue and one of the leading causes of death worldwide [...].
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Affiliation(s)
| | - Mohamed Amiche
- Laboratoire de Biogenèse des Signaux Peptidiques (BioSiPe), Institut de Biologie Paris-Seine, Sorbonne Université-CNRS, 75252 Paris, France
| | - Jean-Eric Ghia
- Department of Immunology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0T5, Canada
- Section of Gastroenterology, Department of Internal Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0T5, Canada
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Fecal chromogranins and secretogranins are linked to the fecal and mucosal intestinal bacterial composition of IBS patients and healthy subjects. Sci Rep 2018; 8:16821. [PMID: 30429499 PMCID: PMC6235916 DOI: 10.1038/s41598-018-35241-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 11/01/2018] [Indexed: 12/22/2022] Open
Abstract
Altered fecal levels of chromogranins (Cg) and secretogranins (Sg) are demonstrated in irritable bowel syndrome (IBS), but their role in IBS pathophysiology remains unknown. This study aimed to determine if granins are associated with bacterial composition, immune activation and IBS symptoms. Protein levels of fecal granins (CgA, CgB, SgII and SgIII) were analysed with immunoassays. Mucosal mRNA expression of granins, TPH1 and immune markers were evaluated with RT-qPCR. 16S rRNA gene sequencing was performed on fecal and mucosal bacteria. The intestinal granin profile, based on fecal protein levels and mucosal mRNA expression, could not discriminate between IBS patients (n = 88) and healthy subjects (HS, n = 33). IBS patients dominated by high fecal or mucosal granin levels, respectively, did not differ in symptom or immune profiles. Fecal-dominated and mucosal-dominated granin clusters of IBS patients and HS, demonstrated separate fecal and mucosal bacterial profiles and high fecal abundance of granins were associated with a less diverse bacterial composition and the Bacteroides enterotype. The intestinal granin profiles of IBS patients and HS are linked to the intestinal bacterial composition, diversity and enterotypes. These findings suggest that granins may be one of several host-produced factors regulating the microbiota composition of the intestine.
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Troger J, Theurl M, Kirchmair R, Pasqua T, Tota B, Angelone T, Cerra MC, Nowosielski Y, Mätzler R, Troger J, Gayen JR, Trudeau V, Corti A, Helle KB. Granin-derived peptides. Prog Neurobiol 2017; 154:37-61. [PMID: 28442394 DOI: 10.1016/j.pneurobio.2017.04.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 04/10/2017] [Accepted: 04/16/2017] [Indexed: 12/14/2022]
Abstract
The granin family comprises altogether 7 different proteins originating from the diffuse neuroendocrine system and elements of the central and peripheral nervous systems. The family is dominated by three uniquely acidic members, namely chromogranin A (CgA), chromogranin B (CgB) and secretogranin II (SgII). Since the late 1980s it has become evident that these proteins are proteolytically processed, intragranularly and/or extracellularly into a range of biologically active peptides; a number of them with regulatory properties of physiological and/or pathophysiological significance. The aim of this comprehensive overview is to provide an up-to-date insight into the distribution and properties of the well established granin-derived peptides and their putative roles in homeostatic regulations. Hence, focus is directed to peptides derived from the three main granins, e.g. to the chromogranin A derived vasostatins, betagranins, pancreastatin and catestatins, the chromogranin B-derived secretolytin and the secretogranin II-derived secretoneurin (SN). In addition, the distribution and properties of the chromogranin A-derived peptides prochromacin, chromofungin, WE14, parastatin, GE-25 and serpinins, the CgB-peptide PE-11 and the SgII-peptides EM66 and manserin will also be commented on. Finally, the opposing effects of the CgA-derived vasostatin-I and catestatin and the SgII-derived peptide SN on the integrity of the vasculature, myocardial contractility, angiogenesis in wound healing, inflammatory conditions and tumors will be discussed.
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Affiliation(s)
- Josef Troger
- Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria.
| | - Markus Theurl
- Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Rudolf Kirchmair
- Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Teresa Pasqua
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Bruno Tota
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Tommaso Angelone
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Maria C Cerra
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Yvonne Nowosielski
- Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria
| | - Raphaela Mätzler
- Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria
| | - Jasmin Troger
- Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Vance Trudeau
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Angelo Corti
- Vita-Salute San Raffaele University and Division of Experimental Oncology, San Raffaele Scientific Institute, Milan, Italy
| | - Karen B Helle
- Department of Biomedicine, University of Bergen, Norway
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Zaw TS, Khin PP, Sohn UD. The signaling of amitriptyline-induced inhibitory effect on electrical field stimulation response in colon smooth muscle. Naunyn Schmiedebergs Arch Pharmacol 2016; 389:961-70. [PMID: 27234925 DOI: 10.1007/s00210-016-1259-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/11/2016] [Indexed: 12/16/2022]
Abstract
Amitriptyline, a well-known antidepressant, exerts inhibitory effect on electrically stimulated rat colon smooth muscle contraction. In this study, we investigated the signaling pathway of amitriptyline-induced inhibitory effect. Changes in isometric force of colon muscle were recorded on polygraph, and data were analyzed by measuring the inhibitory extent induced by amitriptyline. Firstly, muscles were contracted by stimulation with electric field stimulation (EFS), and then, amitriptyline was added cumulatively to determine its influence effect on EFS. Amitriptyline significantly inhibited EFS-induced contraction dose dependently. Then, the mechanism of inhibitory effect of amitriptyline was evaluated by pretreating with various antagonists such as L-NAME, methylene blue, atropine, 5-HT receptors blockers, guanethidine, prazosin, guanabenz, isoprenaline, Y27632 (Rho-kinase inhibitor), ML9 (myosin light chain kinase (MLCK) inhibitor), U73122 (PLC inhibitor), and chelerythrine (PKC inhibitor). Then, Ca(2+) channel blocker (nifedipine) and K(+)channel blockers, tetraethylammonium (TEA), 4-aminopyridine (4-AP), and glybenclamide, were used to determine the involvement of ion channels. L-NAME, guanabenz, 5HT4 receptor blocker, ML9, and Y27632 enhanced the effect of amitriptyline. Meanwhile, methylene blue, atropine, guanethidine, prazosin, methylsergide, ondansetron, U73122, and chelerythrine blocked its effect. It was also shown that nifedipine enhanced but TEA and glybenclamide blocked amitriptyline-induced inhibitory effect on EFS. Our results indicated that amitriptyline may exert inhibitory effect in response to EFS by inhibiting muscarinic receptors and then PLC-mediated PKC pathway leading to opening of ATP-sensitive potassium channel.
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Affiliation(s)
- Tin Sandar Zaw
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Phyu Phyu Khin
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Uy Dong Sohn
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea.
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Nagy JI, Urena-Ramirez V, Ghia JE. Functional alterations in gut contractility after connexin36 ablation and evidence for gap junctions forming electrical synapses between nitrergic enteric neurons. FEBS Lett 2014; 588:1480-90. [PMID: 24548563 PMCID: PMC4043341 DOI: 10.1016/j.febslet.2014.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 02/05/2014] [Accepted: 02/06/2014] [Indexed: 02/02/2023]
Abstract
Neurons in the enteric nervous system utilize numerous neurotransmitters to orchestrate rhythmic gut smooth muscle contractions. We examined whether electrical synapses formed by gap junctions containing connexin36 also contribute to communication between enteric neurons in mouse colon. Spontaneous contractility properties and responses to electrical field stimulation and cholinergic agonist were altered in gut from connexin36 knockout vs. wild-type mice. Immunofluorescence revealed punctate labelling of connexin36 that was localized at appositions between somata of enteric neurons immunopositive for the enzyme nitric oxide synthase. There is indication for a possible functional role of gap junctions between inhibitory nitrergic enteric neurons.
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Affiliation(s)
- James Imre Nagy
- Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
| | - Viridiana Urena-Ramirez
- Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada; Department of Immunology and Internal Medicine section of Gastroenterology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
| | - Jean-Eric Ghia
- Department of Immunology and Internal Medicine section of Gastroenterology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
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Altered levels of fecal chromogranins and secretogranins in IBS: relevance for pathophysiology and symptoms? Am J Gastroenterol 2012; 107:440-7. [PMID: 22233694 DOI: 10.1038/ajg.2011.458] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Chromogranins (Cg) and secretogranins (Sg) are proteins ubiquitous in secretory cells of the enteric, endocrine, and immune systems, and may reflect activity of these systems. We therefore performed a hypothesis generating study to evaluate the association between fecal levels of CgA, CgB, SgII, and SgIII, with the clinical and pathophysiological phenotype of irritable bowel syndrome (IBS) patients. METHODS Analyses of CgA, CgB, SgII, SgIII, and calprotectin in fecal samples of 82 IBS patients and 29 healthy controls were performed. All IBS subjects completed validated questionnaires to assess gastrointestinal and psychological symptom severity, and underwent rectal barostat test and colonic transit time measurement. RESULTS IBS patients demonstrated higher levels of fecal CgA (P=0.009), SgII (P<0.001), and SgIII (P<0.001), but lower levels of CgB (P<0.001) compared with controls. SgII had good discriminative validity to positively identify IBS patients, with an area under the receiver operating characteristics (ROC) curve (AUROC) of 0.86 (95% confidence interval (CI): 0.78-0.94). SgIII and CgB both had fairly good discriminative validity to positively identify IBS patients, with an AUROC of 0.79 (95% CI: 0.71-0.87) and 0.78 (95% CI: 0.69-0.87), respectively. There were negative correlations between the colonic transit time and fecal levels of CgA (r=-0.53, P<0.001), SgII (r=-0.55, P<0.001), and SgIII (r=-0.28, P=0.03). Perceived abdominal pain was moderately associated with levels of CgA (r=0.32, P=0.004), SgII (r=0.31, P=0.006), and SgIII (r=0.24, P=0.04). Calprotectin levels were not associated with the levels of granins or with the clinical or pathophysiological phenotype of IBS patients. CONCLUSIONS Fecal levels of Cg and Sg may be related to the underlying pathophysiology of IBS and of potential importance for symptoms of the patients. Granins also show promise to serve as future biomarkers of IBS. Further studies are needed to explore the potential role of granins in IBS patients.
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Abstract
Gut inflammation is characterized by mucosal recruitment of activated cells from both the innate and adaptive immune systems. In addition to immune cells, inflammation in the gut is associated with an alteration in enteric endocrine cells and various biologically active compounds produced by these cells. Although the change in enteric endocrine cells or their products is considered to be important in regulating gut physiology (motility and secretion), it is not clear whether the change plays any role in immune activation and in the regulation of gut inflammation. Due to the strategic location of enteric endocrine cells in gut mucosa, these gut hormones may play an important role in immune activation and promotion of inflammation in the gut. This review addresses the research on the interface between immune and endocrine systems in gastrointestinal (GI) pathophysiology, specifically in the context of two major products of enteric endocrine systems, namely serotonin (5-hydroxytryptamine: 5-HT) and chromogranins (Cgs), in relation to immune activation and generation of inflammation. The studies reviewed in this paper demonstrate that 5-HT activates the immune cells to produce proinflammatory mediators and by manipulating the 5-HT system it is possible to modulate gut inflammation. In the case of Cgs the scenario is more complex, as this hormone has been shown to play both proinflammatory and anti-inflammatory functions. It is also possible that interaction between 5-HT and Cgs may play a role in the modulation of immune and inflammatory responses. In addition to enhancing our understanding of immunoendocrine interaction in the gut, the data generated from the these studies may have implications in understanding the role of gut hormone in the pathogenesis of both GI and non-GI inflammatory diseases which may lead ultimately to improved therapeutic strategies in inflammatory disorders.
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Affiliation(s)
- W I Khan
- Farncombe Family Digestive Health Research Institute, Department of Pathology and Molecular Medicine, McMaster University, ON, Canada.
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Helle KB. Chromogranins A and B and secretogranin II as prohormones for regulatory peptides from the diffuse neuroendocrine system. Results Probl Cell Differ 2010; 50:21-44. [PMID: 20217490 DOI: 10.1007/400_2009_26] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Chromogranin A (CgA), chromogranin B (CgB), and secretogranin II (SgII) belong to a family of uniquely acidic secretory proteins in elements of the diffuse neuroendocrine system. These "granins" are characterized by numerous pairs of basic amino acids as potential sites for intra- and extragranular processing. In response to adequate stimuli, the granins are coreleased with neurotransmitters and hormones and appear in the circulation as potential modulators of homeostatic processes. This review is directed towards functional aspects of the secreted CgA, CgB, and SgII and their biologically active sequences. Widely different effects and targets have been reported for granin-derived peptides. So far, the CgA peptides vasostatin-I, pancreastatin, and catestatin, the CgB peptides CgB(1-41) and secretolytin, and the SgII peptide secretoneurin are the most likely candidates for granin-derived regulatory peptides. Most of their effects fit into patterns of direct or indirect modulations of major functions, in particular associated with inflammatory conditions.
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Affiliation(s)
- Karen B Helle
- Department of Biomedicine, Division of Physiology, University of Bergen, Jonas Lies vei 91, 5009, Bergen, Norway.
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Helle KB. Regulatory peptides from chromogranin A and secretogranin II: putative modulators of cells and tissues involved in inflammatory conditions. ACTA ACUST UNITED AC 2009; 165:45-51. [PMID: 19800929 DOI: 10.1016/j.regpep.2009.09.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 09/16/2009] [Accepted: 09/24/2009] [Indexed: 11/16/2022]
Abstract
Chromogranin A (CgA) and secretogranin II (SgII) of the granin family of uniquely acidic proteins secreted from elements of the diffuse neuroendocrine system are also produced by cells involved in inflammation. CgA and the CgA-derived peptides vasostatin-I and catestatin are products of polymorphonuclear neutrophils accumulating at sites of injury or infections while SgII and the Sg II-derived secretoneurin may contribute to neurogenic inflammation when released from sensory nerve terminals. This review is directed towards vasostatin-I, catestatin and secretoneurin as modulators of cells and tissues associated with inflammatory conditions. The accumulated literature indicates that concerted effects of vasostatin-I and catestatin may be relevant for the first-line host-defence against invading microorganisms, contrasting the apparent lack of antibacterial potencies in secretoneurin. Oppositely directed effects of vasostatin-I and secretoneurin on endothelial permeability and transendothelial extravasation are particularly striking. While vasostatin-I protects the integrity of the endothelial barrier against the disruptive effects of proinflammatory agents, secretoneurin activates transendothelial extravasation, chemotaxis and migration of leukocytes. Oppositely directed effects of vasostatin-I and secretoneurin on formation of blood vessels are also indicated, vasostatin-I inhibiting angiogenetic parameters while secretoneurin activates not only angiogenesis but also vascularization.
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Affiliation(s)
- Karen B Helle
- Department of Biomedicine, University of Bergen, Jonas Lies Vei 91, 5009 Bergen, Norway.
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Zhang D, Shooshtarizadeh P, Laventie BJ, Colin DA, Chich JF, Vidic J, de Barry J, Chasserot-Golaz S, Delalande F, Van Dorsselaer A, Schneider F, Helle K, Aunis D, Prévost G, Metz-Boutigue MH. Two chromogranin a-derived peptides induce calcium entry in human neutrophils by calmodulin-regulated calcium independent phospholipase A2. PLoS One 2009; 4:e4501. [PMID: 19225567 PMCID: PMC2639705 DOI: 10.1371/journal.pone.0004501] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Accepted: 01/15/2009] [Indexed: 12/11/2022] Open
Abstract
Background Antimicrobial peptides derived from the natural processing of chromogranin A (CgA) are co-secreted with catecholamines upon stimulation of chromaffin cells. Since PMNs play a central role in innate immunity, we examine responses by PMNs following stimulation by two antimicrobial CgA-derived peptides. Methodology/Principal Findings PMNs were treated with different concentrations of CgA-derived peptides in presence of several drugs. Calcium mobilization was observed by using flow cytometry and calcium imaging experiments. Immunocytochemistry and confocal microscopy have shown the intracellular localization of the peptides. The calmodulin-binding and iPLA2 activating properties of the peptides were shown by Surface Plasmon Resonance and iPLA2 activity assays. Finally, a proteomic analysis of the material released after PMNs treatment with CgA-derived peptides was performed by using HPLC and Nano-LC MS-MS. By using flow cytometry we first observed that after 15 s, in presence of extracellular calcium, Chromofungin (CHR) or Catestatin (CAT) induce a concentration-dependent transient increase of intracellular calcium. In contrast, in absence of extra cellular calcium the peptides are unable to induce calcium depletion from the stores after 10 minutes exposure. Treatment with 2-APB (2-aminoethoxydiphenyl borate), a store operated channels (SOCs) blocker, inhibits completely the calcium entry, as shown by calcium imaging. We also showed that they activate iPLA2 as the two CaM-binding factors (W7 and CMZ) and that the two sequences can be aligned with the two CaM-binding domains reported for iPLA2. We finally analyzed by HPLC and Nano-LC MS-MS the material released by PMNs following stimulation by CHR and CAT. We characterized several factors important for inflammation and innate immunity. Conclusions/Significance For the first time, we demonstrate that CHR and CAT, penetrate into PMNs, inducing extracellular calcium entry by a CaM-regulated iPLA2 pathway. Our study highlights the role of two CgA-derived peptides in the active communication between neuroendocrine and immune systems.
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Affiliation(s)
- Dan Zhang
- INSERM U575, Physiopathologie du Système Nerveux, Strasbourg, France
- Département de Réanimation Médicale, Hôpital de Hautepierre, Strasbourg, France
- First Hospital, Chongqing University of Medical Sciences, Chongqing, China
| | | | - Benoît-Joseph Laventie
- UPRES-EA 3432, Institut de Bactériologie de la Faculté de Médecine, Université Louis Pasteur, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Didier André Colin
- UPRES-EA 3432, Institut de Bactériologie de la Faculté de Médecine, Université Louis Pasteur, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Jean-François Chich
- INSERM U575, Physiopathologie du Système Nerveux, Strasbourg, France
- INRA, Virologie et Immunologie Moléculaires, Jouy-en-Josas, France
| | - Jasmina Vidic
- INRA, Virologie et Immunologie Moléculaires, Jouy-en-Josas, France
| | - Jean de Barry
- Institut des Neurosciences Cellulaires et Intégratives, UMR 7168 CNRS-Université Louis Pasteur, Strasbourg, France
| | - Sylvette Chasserot-Golaz
- Institut des Neurosciences Cellulaires et Intégratives, UMR 7168 CNRS-Université Louis Pasteur, Strasbourg, France
| | | | - Alain Van Dorsselaer
- Laboratoire de spectrométrie de masse BioOrganique, IPHC-DSA, ULP, CNRS, UMR7178, Strasbourg, France
| | - Francis Schneider
- Département de Réanimation Médicale, Hôpital de Hautepierre, Strasbourg, France
| | - Karen Helle
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Dominique Aunis
- INSERM U575, Physiopathologie du Système Nerveux, Strasbourg, France
| | - Gilles Prévost
- UPRES-EA 3432, Institut de Bactériologie de la Faculté de Médecine, Université Louis Pasteur, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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Amato A, Serio R, Mulè F. Relaxation induced by N-terminal fragments of chromogranin A in mouse gastric preparations. REGULATORY PEPTIDES 2007; 139:90-5. [PMID: 17126925 DOI: 10.1016/j.regpep.2006.10.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Revised: 10/10/2006] [Accepted: 10/18/2006] [Indexed: 05/12/2023]
Abstract
A definitive role for chromogranin A (CGA)-derived fragments in the control of the gastrointestinal smooth muscle contractility has not been yet established. The purpose of the present study was to evaluate, in vitro, the effects of the recombinant vasostatin 1-78 (VS-1), CGA 7-57 and CGA 47-66 on the mouse gastric mechanical activity, recording the changes of intraluminal pressure. VS-1, CGA 7-57 and CGA 47-66 produced concentration-dependent relaxations. Mouse anti-vasostatin-1 monoclonal antibody 5A8, recognising the region 53-57, abolished the relaxation induced by VS-1, indicating the specificity of the effect. The relaxation was significantly reduced by tetrodotoxin (TTX), blocker of neuronal voltage-dependent Na(+) channels, l-NAME, inhibitor of nitric oxide (NO) synthase, or apamin, blocker of small conductance Ca(2+)-dependent K(+) channels. The joint application of TTX and l-NAME did not show any additive effects, whereas TTX plus apamin abolished the VS-1 response. The results suggest that the N-terminal CGA-derived peptides are able to relax mouse gastric muscle and, therefore, they point out an inhibitory role of vasostatin I in the gastrointestinal tract. The relaxation is mediated in part by neural mechanisms through NO production and in part by non-neural mechanisms involving the opening of small conductance Ca(2+)-dependent K(+) channels.
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Affiliation(s)
- Antonella Amato
- Dipartimento di Biologia cellulare e dello Sviluppo, Università di Palermo, 90128 Palermo, Italy
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