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Subhan F, Zizzo MG, Serio R. Motor dysfunction of the gut in Duchenne muscular dystrophy: A review. Neurogastroenterol Motil 2024:e14804. [PMID: 38651673 DOI: 10.1111/nmo.14804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/06/2024] [Accepted: 04/09/2024] [Indexed: 04/25/2024]
Abstract
BACKGROUND Duchenne's muscular dystrophy (DMD) is a severe type of hereditary, neuromuscular disorder caused by a mutation in the dystrophin gene resulting in the absence or production of truncated dystrophin protein. Conventionally, clinical descriptions of the disorder focus principally on striated muscle defects; however, DMD manifestations involving gastrointestinal (GI) smooth muscle have been reported, even if not rigorously studied. PURPOSE The objective of the present review is to offer a comprehensive perspective on the existing knowledge concerning GI manifestations in DMD, focusing the attention on evidence in DMD patients and mdx mice. This includes an assessment of symptomatology, etiological pathways, and potential corrective approaches. This paper could provide helpful information about DMD gastrointestinal implications that could serve as a valuable orientation for prospective research endeavors in this field. This manuscript emphasizes the effectiveness of mdx mice, a DMD animal model, in unraveling mechanistic insights and exploring the pathological alterations in the GI tract. The gastrointestinal consequences evident in patients with DMD and the mdx mice models are a significant area of focus for researchers. The exploration of this area in depth could facilitate the development of more efficient therapeutic approaches and improve the well-being of individuals impacted by the condition.
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Affiliation(s)
- Fazal Subhan
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, Palermo, Italy
| | - Maria Grazia Zizzo
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, Palermo, Italy
- ATeN (Advanced Technologies Network) Center, Viale delle Scienze, University of Palermo, Palermo, Italy
| | - Rosa Serio
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, Palermo, Italy
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Idrizaj E, Garella R, Nistri S, Squecco R, Baccari MC. Evidence that resistin acts on the mechanical responses of the mouse gastric fundus. Front Physiol 2022; 13:930197. [PMID: 35910552 PMCID: PMC9334560 DOI: 10.3389/fphys.2022.930197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/27/2022] [Indexed: 11/30/2022] Open
Abstract
Resistin, among its several actions, has been reported to exert central anorexigenic effects in rodents. Some adipokines which centrally modulate food intake have also been reported to affect the activity of gastric smooth muscle, whose motor responses represent a source of peripheral signals implicated in the control of the hunger-satiety cycle through the gut-brain axis. On this basis, in the present experiments, we investigated whether resistin too could affect the mechanical responses in the mouse longitudinal gastric fundal strips. Electrical field stimulation (EFS) elicited tetrodotoxin- and atropine-sensitive contractile responses. Resistin reduced the amplitude of the EFS-induced contractile responses. This effect was no longer detected in the presence of L-NNA, a nitric oxide (NO) synthesis inhibitor. Resistin did not influence the direct muscular response to methacholine. In the presence of carbachol and guanethidine, EFS elicited inhibitory responses whose amplitude was increased by resistin. L-NNA abolished the inhibitory responses evoked by EFS, indicating their nitrergic nature. In the presence of L-NNA, resistin did not have any effect on the EFS-evoked inhibitory responses. Western blot and immunofluorescence analysis revealed a significant increase in neuronal nitric oxide synthase (nNOS) expression in neurons of the myenteric plexus following resistin exposure. In conclusion, the present results offer the first evidence that resistin acts on the gastric fundus, likely through a modulatory action on the nitrergic neurotransmission.
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Affiliation(s)
- Eglantina Idrizaj
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
- *Correspondence: Eglantina Idrizaj, ; Maria Caterina Baccari,
| | - Rachele Garella
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - Silvia Nistri
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Florence, Italy
| | - Roberta Squecco
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - Maria Caterina Baccari
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
- *Correspondence: Eglantina Idrizaj, ; Maria Caterina Baccari,
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3
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Traini C, Nistri S, Calosi L, Vannucchi MG. Chronic Exposure to Cigarette Smoke Affects the Ileum and Colon of Guinea Pigs Differently. Relaxin (RLX-2, Serelaxin) Prevents Most Local Damage. Front Pharmacol 2022; 12:804623. [PMID: 35095510 PMCID: PMC8793690 DOI: 10.3389/fphar.2021.804623] [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: 10/29/2021] [Accepted: 12/09/2021] [Indexed: 11/13/2022] Open
Abstract
Cigarette smoking (CS) is the cause of several organ and apparatus diseases. The effects of smoke in the gut are partially known. Accumulating evidence has shown a relationship between smoking and inflammatory bowel disease, prompting us to investigate the mechanisms of action of smoking in animal models. Despite the role played by neuropeptides in gut inflammation, there are no reports on their role in animal models of smoking exposure. The hormone relaxin has shown anti-inflammatory properties in the intestine, and it might represent a putative therapy to prevent gut damage caused by smoking. Presently, we investigate the effects of chronic smoke exposure on inflammation, mucosal secretion, and vasoactive intestinal peptide (VIP) and substance P (SP) expressions in the ileum and colon of guinea pigs. We also verify the ability of relaxin to counter the smoke-induced effects. Smoke impacted plasma carbon monoxide (CO). In the ileum, it induced inflammatory infiltrates, fibrosis, and acidic mucin production; reduced the blood vessel area; decreased c-kit-positive mast cells and VIP-positive neurons; and increased the SP-positive nerve fibers. In the colon, it reduced the blood vessel area and the goblet cell area and decreased c-kit-positive mast cells, VIP-positive neurons, and SP-positive nerve fibers. Relaxin prevented most of the smoking-induced changes in the ileum, while it was less effective in the colon. This study shows the diverse sensitivity to CS between the ileum and the colon and demonstrates that both VIP and SP are affected by smoking. The efficacy of relaxin proposes this hormone as a potential anti-inflammatory therapeutic to counteract gut damage in humans affected by inflammatory bowel diseases.
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Affiliation(s)
- Chiara Traini
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Florence, Italy
| | - Silvia Nistri
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Florence, Italy
| | - Laura Calosi
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Florence, Italy
| | - Maria Giuliana Vannucchi
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Florence, Italy
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4
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Investigating the Potential for Sulforaphane to Attenuate Gastrointestinal Dysfunction in mdx Dystrophic Mice. Nutrients 2021; 13:nu13124559. [PMID: 34960110 PMCID: PMC8706299 DOI: 10.3390/nu13124559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 12/30/2022] Open
Abstract
Gastrointestinal (GI) dysfunction is an important, yet understudied condition associated with Duchenne muscular dystrophy (DMD), with patients reporting bloating, diarrhea, and general discomfort, contributing to a reduced quality of life. In the mdx mouse, the most commonly used mouse model of DMD, studies have confirmed GI dysfunction (reported as altered contractility and GI transit through the small and large intestine), associated with increased local and systemic inflammation. Sulforaphane (SFN) is a natural isothiocyanate with anti-inflammatory and anti-oxidative properties via its activation of Nrf2 signalling that has been shown to improve aspects of the skeletal muscle pathology in dystrophic mice. Whether SFN can similarly improve GI function in muscular dystrophy was unknown. Video imaging and spatiotemporal mapping to assess gastrointestinal contractions in isolated colon preparations from mdx and C57BL/10 mice revealed that SFN reduced contraction frequency when administered ex vivo, demonstrating its therapeutic potential to improve GI function in DMD. To confirm this in vivo, four-week-old male C57BL/10 and mdx mice received vehicle (2% DMSO/corn oil) or SFN (2 mg/kg in 2% DMSO/corn oil) via daily oral gavage five days/week for 4 weeks. SFN administration reduced fibrosis in the diaphragm of mdx mice but did not affect other pathological markers. Gene and protein analysis revealed no change in Nrf2 protein expression or activation of Nrf2 signalling after SFN administration and oral SFN supplementation did not improve GI function in mdx mice. Although ex vivo studies demonstrate SFN’s therapeutic potential for reducing colon contractions, in vivo studies should investigate higher doses and/or alternate routes of administration to confirm SFN’s potential to improve GI function in DMD.
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Nitric Oxide: From Gastric Motility to Gastric Dysmotility. Int J Mol Sci 2021; 22:ijms22189990. [PMID: 34576155 PMCID: PMC8470306 DOI: 10.3390/ijms22189990] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/11/2021] [Accepted: 09/13/2021] [Indexed: 12/27/2022] Open
Abstract
It is known that nitric oxide (NO) plays a key physiological role in the control of gastrointestinal (GI) motor phenomena. In this respect, NO is considered as the main non-adrenergic, non-cholinergic (NANC) inhibitory neurotransmitter responsible for smooth muscle relaxation. Moreover, many substances (including hormones) have been reported to modulate NO production leading to changes in motor responses, further underlying the importance of this molecule in the control of GI motility. An impaired NO production/release has indeed been reported to be implicated in some GI dysmotility. In this article we wanted to focus on the influence of NO on gastric motility by summarizing knowledge regarding its role in both physiological and pathological conditions. The main role of NO on regulating gastric smooth muscle motor responses, with particular reference to NO synthases expression and signaling pathways, is discussed. A deeper knowledge of nitrergic mechanisms is important for a better understanding of their involvement in gastric pathophysiological conditions of hypo- or hyper-motility states and for future therapeutic approaches. A possible role of substances which, by interfering with NO production, could prove useful in managing such motor disorders has been advanced.
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Swiderski K, Bindon R, Trieu J, Naim T, Schokman S, Swaminathan M, Leembruggen AJL, Hill-Yardin EL, Koopman R, Bornstein JC, Lynch GS. Spatiotemporal Mapping Reveals Regional Gastrointestinal Dysfunction in mdx Dystrophic Mice Ameliorated by Oral L-arginine Supplementation. J Neurogastroenterol Motil 2020; 26:133-146. [PMID: 31715094 PMCID: PMC6955187 DOI: 10.5056/jnm19029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 07/09/2019] [Accepted: 07/23/2019] [Indexed: 12/25/2022] Open
Abstract
Background/Aims Patients with Duchenne muscular dystrophy exhibit significant, ongoing impairments in gastrointestinal (GI) function likely resulting from dysregulated nitric oxide production. Compounds increasing neuronal nitric oxide synthase expression and/or activity could improve GI dysfunction and enhance quality of life for dystrophic patients. We used video imaging and spatiotemporal mapping to identify GI dysfunction in mdx dystrophic mice and determine whether dietary intervention to enhance nitric oxide could alleviate aberrant colonic activity in muscular dystrophy. Methods Four-week-old male C57BL/10 and mdx mice received a specialized diet either with no supplementation (control) or supplemented (1 g/kg/day) with L-alanine, L-arginine, or L-citrulline for 8 weeks. At the conclusion of treatment, mice were sacrificed by cervical dislocation and colon motility examined by spatiotemporal (ST) mapping ex vivo. Results ST mapping identified increased contraction number in the mid and distal colon of mdx mice on control and L-alanine supplemented diets relative to C57BL/10 mice (P < 0.05). Administration of either L-arginine or L-citrulline attenuated contraction number in distal colons of mdx mice relative to C57BL/10 mice. Conclusions GI dysfunction in Duchenne muscular dystrophy has been sadly neglected as an issue affecting quality of life. ST mapping identified regional GI dysfunction in the mdx dystrophic mouse. Dietary interventions to increase nitric oxide signaling in the GI tract reduced the number of colonic contractions and alleviated colonic constriction at rest. These findings in mdx mice reveal that L-arginine can improve colonic motility and has potential therapeutic relevance for alleviating GI discomfort, improving clinical care, and enhancing quality of life in Duchenne muscular dystrophy.
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Affiliation(s)
- Kristy Swiderski
- Centre for Muscle Research, Department of Physiology, School of Biomedical Sciences, The University of Melbourne, Australia
| | - Rebecka Bindon
- Centre for Muscle Research, Department of Physiology, School of Biomedical Sciences, The University of Melbourne, Australia
| | - Jennifer Trieu
- Centre for Muscle Research, Department of Physiology, School of Biomedical Sciences, The University of Melbourne, Australia
| | - Timur Naim
- Centre for Muscle Research, Department of Physiology, School of Biomedical Sciences, The University of Melbourne, Australia
| | - Shana Schokman
- Enteric Nervous System Laboratory, Department of Physiology, The University of Melbourne, Australia
| | - Mathusi Swaminathan
- Enteric Nervous System Laboratory, Department of Physiology, The University of Melbourne, Australia
| | - Anita J L Leembruggen
- Enteric Nervous System Laboratory, Department of Physiology, The University of Melbourne, Australia
| | - Elisa L Hill-Yardin
- Enteric Nervous System Laboratory, Department of Physiology, The University of Melbourne, Australia.,Gut-Brain Axis Laboratory, School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia (Current address)
| | - René Koopman
- Centre for Muscle Research, Department of Physiology, School of Biomedical Sciences, The University of Melbourne, Australia
| | - Joel C Bornstein
- Enteric Nervous System Laboratory, Department of Physiology, The University of Melbourne, Australia
| | - Gordon S Lynch
- Centre for Muscle Research, Department of Physiology, School of Biomedical Sciences, The University of Melbourne, Australia
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Idrizaj E, Garella R, Squecco R, Baccari MC. Adipocytes-released Peptides Involved in the Control of Gastrointestinal Motility. Curr Protein Pept Sci 2019; 20:614-629. [PMID: 30663565 DOI: 10.2174/1389203720666190121115356] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 12/18/2022]
Abstract
The present review focuses on adipocytes-released peptides known to be involved in the control of gastrointestinal motility, acting both centrally and peripherally. Thus, four peptides have been taken into account: leptin, adiponectin, nesfatin-1, and apelin. The discussion of the related physiological or pathophysiological roles, based on the most recent findings, is intended to underlie the close interactions among adipose tissue, central nervous system, and gastrointestinal tract. The better understanding of this complex network, as gastrointestinal motor responses represent peripheral signals involved in the regulation of food intake through the gut-brain axis, may also furnish a cue for the development of either novel therapeutic approaches in the treatment of obesity and eating disorders or potential diagnostic tools.
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Affiliation(s)
- Eglantina Idrizaj
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - Rachele Garella
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - Roberta Squecco
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - Maria Caterina Baccari
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
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8
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Idrizaj E, Garella R, Castellini G, Mohr H, Pellegata NS, Francini F, Ricca V, Squecco R, Baccari MC. Adiponectin affects the mechanical responses in strips from the mouse gastric fundus. World J Gastroenterol 2018; 24:4028-4035. [PMID: 30254407 PMCID: PMC6148421 DOI: 10.3748/wjg.v24.i35.4028] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/12/2018] [Accepted: 07/21/2018] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate whether the adipocytes derived hormone adiponectin (ADPN) affects the mechanical responses in strips from the mouse gastric fundus.
METHODS For functional experiments, gastric strips from the fundal region were cut in the direction of the longitudinal muscle layer and placed in organ baths containing Krebs-Henseleit solution. Mechanical responses were recorded via force-displacement transducers, which were coupled to a polygraph for continuous recording of isometric tension. Electrical field stimulation (EFS) was applied via two platinum wire rings through which the preparation was threaded. The effects of ADPN were investigated on the neurally-induced contractile and relaxant responses elicited by EFS. The expression of ADPN receptors, Adipo-R1 and Adipo-R2, was also evaluated by touchdown-PCR analysis.
RESULTS In the functional experiments, EFS (4-16 Hz) elicited tetrodotoxin (TTX)-sensitive contractile responses. Addition of ADPN to the bath medium caused a reduction in amplitude of the neurally-induced contractile responses (P < 0.05). The effects of ADPN were no longer observed in the presence of the nitric oxide (NO) synthesis inhibitor L-NG-nitro arginine (L-NNA) (P > 0.05). The direct smooth muscle response to methacholine was not influenced by ADPN (P > 0.05). In carbachol precontracted strips and in the presence of guanethidine, EFS induced relaxant responses. Addition of ADPN to the bath medium, other than causing a slight and progressive decay of the basal tension, increased the amplitude of the neurally-induced relaxant responses (P < 0.05). Touchdown-PCR analysis revealed the expression of both Adipo-R1 and Adipo-R2 in the gastric fundus.
CONCLUSION The results indicate for the first time that ADPN is able to influence the mechanical responses in strips from the mouse gastric fundus.
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Affiliation(s)
- Eglantina Idrizaj
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Rachele Garella
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Giovanni Castellini
- Psychiatry Unit, Department of Health Sciences, University of Florence, Florence 50134, Italy
| | - Hermine Mohr
- Institute for Diabetes and Cancer, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Natalia S Pellegata
- Institute for Diabetes and Cancer, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Fabio Francini
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Valdo Ricca
- Psychiatry Unit, Department of Health Sciences, University of Florence, Florence 50134, Italy
| | - Roberta Squecco
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Maria Caterina Baccari
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
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Feder D, Ierardi M, Covre AL, Petri G, Carvalho AADS, Fonseca FLA, Bertassoli BM. Evaluation of the gastrointestinal tract in mdx mice: an experimental model of Duchenne muscular dystrophy. APMIS 2018; 126:693-699. [PMID: 30168625 DOI: 10.1111/apm.12864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/06/2018] [Indexed: 12/12/2022]
Abstract
This study describes the functional and morphological alterations in the intestines of mdx mice (n = 4) compared with the intestinal features of C57BL/10 mice (n = 7) at 2 months of age. The whole gut transit time (carmine red) and the upper gut transit time (activated charcoal) were measured, and light microscopy was utilized to view stained sections (H&E and picrosirius red) for histological analysis. No significant difference in mean evacuation time for the whole gut was observed between the two groups, but a significant delay in activated charcoal passage was observed in the mdx mice. Visually, a higher concentration of collagen fibers in the submucosal region was apparent in the mdx mice. The concentration of collagen fibers in the stomach and small intestine suggests a direct relationship with the decrease in motility of the upper gastrointestinal tract in the mdx mice. Further experimental studies should be conducted to develop therapeutic alternatives to collagen inhibition to control these manifestations.
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Affiliation(s)
- David Feder
- Pharmacology Department, Faculdade de Medicina do ABC, Santo André, SP, Brazil
| | - Mariana Ierardi
- Pharmacology Department, Faculdade de Medicina do ABC, Santo André, SP, Brazil
| | - Ana Laura Covre
- Pharmacology Department, Faculdade de Medicina do ABC, Santo André, SP, Brazil
| | - Giuliana Petri
- Pharmacology Department, Faculdade de Medicina do ABC, Santo André, SP, Brazil
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Idrizaj E, Garella R, Francini F, Squecco R, Baccari MC. Relaxin influences ileal muscular activity through a dual signaling pathway in mice. World J Gastroenterol 2018; 24:882-893. [PMID: 29491682 PMCID: PMC5829152 DOI: 10.3748/wjg.v24.i8.882] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/14/2017] [Accepted: 11/27/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the signaling pathways involved in the relaxin (RLX) effects on ileal preparations from mice through mechanical and electrophysiological experiments.
METHODS For mechanical experiments, ileal preparations from female mice were mounted in organ baths containing Krebs-Henseleit solution. The mechanical activity was recorded via force-displacement transducers, which were coupled to a polygraph for continuous recording of isometric tension. Electrophysiological measurements were performed in current- and voltage-clamp conditions by a microelectrode inserted in a single smooth muscle cell (SMC) of the ileal longitudinal layer. Both the membrane passive properties and inward voltage-dependent L-type Ca2+ currents were recorded using suitable solutions and voltage stimulation protocols.
RESULTS Mechanical experiments showed that RLX induced a decay of the basal tension and a reduction in amplitude of the spontaneous contractions. The effects of RLX were partially reduced by 1H-[1,2,4]oxadiazolo[4,3-a]-quinoxalin-1-one (ODQ) or 9-cyclopentyladenine mesylate (9CPA), inhibitors of guanylate cyclase (GC) and adenylate cyclase (AC), respectively, and were abolished in the concomitant presence of both drugs. Electrophysiological experiments demonstrated that RLX directly influenced the biophysical properties of ileal SMCs, decreasing the membrane conductance, hyperpolarizing the resting membrane potential, reducing the L-type calcium current amplitude and affecting its kinetics. The voltage dependence of the current activation and inactivation time constant was significantly speeded by RLX. Each electrophysiological effect of RLX was reduced by ODQ or 9CPA, and abolished in the concomitant presence of both drugs as observed in mechanical experiments.
CONCLUSION Our new findings demonstrate that RLX influences ileal muscle through a dual mechanism involving both GC and AC.
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Affiliation(s)
- Eglantina Idrizaj
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Rachele Garella
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Fabio Francini
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Roberta Squecco
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Maria Caterina Baccari
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
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Garella R, Idrizaj E, Traini C, Squecco R, Vannucchi MG, Baccari MC. Glucagon-like peptide-2 modulates the nitrergic neurotransmission in strips from the mouse gastric fundus. World J Gastroenterol 2017; 23:7211-7220. [PMID: 29142468 PMCID: PMC5677198 DOI: 10.3748/wjg.v23.i40.7211] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/19/2017] [Accepted: 09/26/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate whether glucagon-like peptide-2 (GLP-2) influences the neurally-induced responses in gastric strips from mice, since no data are available.
METHODS For functional experiments, gastric fundal strips were mounted in organ baths containing Krebs-Henseleit solution. Mechanical responses were recorded via force-displacement transducers, which were coupled to a polygraph for continuous recording of isometric tension. Electrical field stimulation (EFS) was applied via two platinum wire rings through which the preparation was threaded. The effects of GLP-2 (2 and 20 nmol/L) were evaluated on the neurally-induced contractile and relaxant responses elicited by EFS. Neuronal nitric oxide synthase (nNOS) enzyme was evaluated by immunohistochemistry.
RESULTS In the functional experiments, electrical field stimulation (EFS, 4-16 Hz) induced tetrodotoxin (TTX)-sensitive contractile responses, which were reduced in amplitude by GLP-2 (P < 0.05). In the presence of the nitric oxide (NO) synthesis inhibitor L-NNA, GLP-2 no longer influenced the neurally-evoked contractile responses (P > 0.05). The direct smooth muscle response to methacholine was not influenced by GLP-2 (P > 0.05). In the presence of guanethidine and carbachol, the addition of GLP-2 to the bath medium evoked TTX-sensitive relaxant responses that were unaffected by L-NNA (P > 0.05). EFS induced a fast NO-mediated relaxation, whose amplitude was enhanced in the presence of the hormone (P < 0.05). Immunohistochemical experiments showed a significant increase (P < 0.05) in nNOS immunoreactivity in the nerve structures after GLP-2 exposure.
CONCLUSION The results demonstrate that in gastric fundal strips, GLP-2 influences the amplitude of neurally-induced responses through the modulation of the nitrergic neurotransmission and increases nNOS expression.
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Affiliation(s)
- Rachele Garella
- Department of Experimental and Clinical Medicine, Section of Physiology, University of Florence, 50134 Florence, Italy
| | - Eglantina Idrizaj
- Department of Experimental and Clinical Medicine, Section of Physiology, University of Florence, 50134 Florence, Italy
| | - Chiara Traini
- Department of Experimental and Clinical Medicine, Histology and Embryology Research Unit, University of Florence, 50134 Florence, Italy
| | - Roberta Squecco
- Department of Experimental and Clinical Medicine, Section of Physiology, University of Florence, 50134 Florence, Italy
| | - Maria Giuliana Vannucchi
- Department of Experimental and Clinical Medicine, Histology and Embryology Research Unit, University of Florence, 50134 Florence, Italy
| | - Maria Caterina Baccari
- Department of Experimental and Clinical Medicine, Section of Physiology, University of Florence, 50134 Florence, Italy
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Pini A, Garella R, Idrizaj E, Calosi L, Baccari MC, Vannucchi MG. Glucagon-like peptide 2 counteracts the mucosal damage and the neuropathy induced by chronic treatment with cisplatin in the mouse gastric fundus. Neurogastroenterol Motil 2016; 28:206-16. [PMID: 26547262 DOI: 10.1111/nmo.12712] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/28/2015] [Indexed: 12/16/2022]
Abstract
BACKGROUND Glucagon-like peptide-2 (GLP-2) is a pleiotropic hormone synthesized and secreted by the enteroendocrine 'L' cells able to exert intestine-trophic and anti-inflammatory effects. The antineoplastic drug cisplatin causes gastrointestinal alterations with clinical symptoms (nausea and vomiting) that greatly affect the therapy compliance. Experimentally, it has been reported that chronic cisplatin treatment caused mucosal damage and enteric neuropathy in the rat colon. METHODS We investigated, through a combined immunohistochemical and functional approach, whether [Gly(2) ]GLP-2, a GLP-2 analog, was able to counteract the detrimental effects of long-term cisplatin administration in the mucosa and myenteric neurons of mouse gastric fundus. KEY RESULTS Morphological experiments showed a reduction in the epithelium thickness in cisplatin-treated mice, which was prevented by [Gly(2) ]GLP-2 co-treatment. Immunohistochemistry demonstrated that cisplatin caused a significant decrease in myenteric neurons, mainly those expressing neuronal nitric oxide synthase (nNOS), that was prevented by [Gly(2) ]GLP-2 co-treatment. In the functional experiments, [Gly(2) ]GLP-2 co-treatment counteracted the increase in amplitude of the neurally induced contractions observed in strips from cisplatin-treated animals. The NO synthesis inhibitor L-N(G) -nitro arginine caused an increase in amplitude of the contractile responses that was greater in preparations from cisplatin+[Gly(2) ]GLP-2 treated mice compared to the cisplatin-treated ones. CONCLUSIONS & INFERENCES The results demonstrate that in cisplatin long-term treated mice [Gly(2) ]GLP-2 is able to counteract both the mucosal gastric fundus damage, by preventing the epithelium thickness decrease, and the neuropathy, by protecting the nNOS neurons. Taken together, the present data suggest that [Gly(2) ]GLP-2 could represent an effective strategy to overcome the distressing gastrointestinal symptoms present during the anti-neoplastic therapy.
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Affiliation(s)
- A Pini
- Department of Experimental and Clinical Medicine, Histology and Embryology Research Unit, University of Florence, Florence, Italy
| | - R Garella
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - E Idrizaj
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - L Calosi
- Department of Experimental and Clinical Medicine, Histology and Embryology Research Unit, University of Florence, Florence, Italy
| | - M C Baccari
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence, Italy
| | - M G Vannucchi
- Department of Experimental and Clinical Medicine, Histology and Embryology Research Unit, University of Florence, Florence, Italy
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Squecco R, Garella R, Idrizaj E, Nistri S, Francini F, Baccari MC. Relaxin Affects Smooth Muscle Biophysical Properties and Mechanical Activity of the Female Mouse Colon. Endocrinology 2015; 156:4398-410. [PMID: 26360621 DOI: 10.1210/en.2015-1428] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The hormone relaxin (RLX) has been reported to influence gastrointestinal motility in mice. However, at present, nothing is known about the effects of RLX on the biophysical properties of the gastrointestinal smooth muscle cells (SMCs). Other than extending previous knowledge of RLX on colonic motility, the purpose of this study was to investigate the ability of the hormone to induce changes in resting membrane potential (RMP) and on sarcolemmal ion channels of colonic SMCs of mice that are related to its mechanical activity. To this aim, we used a combined mechanical and electrophysiological approach. In the mechanical experiments, we observed that RLX caused a decay of the basal tone coupled to an increase of the spontaneous contractions, completely abolished by the guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]-quinoxalin-1-one (ODQ). The electrophysiological results indicate for the first time that RLX directly affects the SMC biophysical properties inducing hyperpolarization of RMP and cycles of slow hyperpolarization/depolarization oscillations. The effects of RLX on RMP were abolished by ODQ as well as by a specific inhibitor of the cGMP-dependent protein kinase, KT5823. RLX reduced Ca(2+) entry through the voltage-dependent L-type channels and modulated either voltage- or ATP-dependent K(+) channels. These effects were abolished by ODQ, suggesting the involvement of the nitric oxide/guanylate cyclase pathway in the effects of RLX on RMP and ion channel modulation. These actions of RLX on membrane properties may contribute to the regulation of the proximal colon motility by the nitric oxide/cGMP/cGMP-dependent protein kinase pathway.
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MESH Headings
- Animals
- Biophysical Phenomena/drug effects
- Calcium/metabolism
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Carbazoles/pharmacology
- Colon/cytology
- Colon/drug effects
- Colon/metabolism
- Cyclic GMP-Dependent Protein Kinases/antagonists & inhibitors
- Female
- Gastrointestinal Motility
- Guanylate Cyclase/antagonists & inhibitors
- KATP Channels/drug effects
- KATP Channels/metabolism
- Membrane Potentials/drug effects
- Mice
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Myenteric Plexus/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Oxadiazoles/pharmacology
- Patch-Clamp Techniques
- Potassium Channels, Voltage-Gated/drug effects
- Potassium Channels, Voltage-Gated/metabolism
- Quinoxalines/pharmacology
- RNA, Messenger/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Relaxin/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- Sarcolemma/drug effects
- Sarcolemma/metabolism
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Affiliation(s)
- Roberta Squecco
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Rachele Garella
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Eglantina Idrizaj
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Silvia Nistri
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Fabio Francini
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Maria Caterina Baccari
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
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Baccari MC, Traini C, Garella R, Cipriani G, Vannucchi MG. Relaxin exerts two opposite effects on mechanical activity and nitric oxide synthase expression in the mouse colon. Am J Physiol Endocrinol Metab 2012; 303:E1142-50. [PMID: 22932783 DOI: 10.1152/ajpendo.00260.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The hormone relaxin exerts a variety of functions on the smooth muscle of reproductive and nonreproductive organs, most of which occur through a nitric oxide (NO)-mediated mechanism. In the stomach and ileum, relaxin causes muscle relaxation by modulating the activity and expression of different nitric oxide synthase (NOS) isoforms region-dependently. Nothing is known on the effects of relaxin in the colon, the gut region expressing the highest number of neuronal (n) NOSβ-immunoreactive neurons and mainly involved in motor symptoms of pregnancy and menstrual cycle. Therefore, we studied the effects of relaxin exposure in the mouse proximal colon in vitro evaluating muscle mechanical activity and NOS isoform expression. The functional experiments showed that relaxin decreases muscle tone and increases amplitude of spontaneous contractions; the immunohistochemical results showed that relaxin increases nNOSβ and endothelial (e) NOS expression in the neurons and decreases nNOSα and eNOS expression in the smooth muscle cells (SMC). We hypothesized that, in the colon, relaxin primarily increases the activity and expression of nNOSβ and eNOS in the neurons, causing a reduction of the muscle tone. The downregulation of nNOSα and eNOS expression in the SMC associated with increased muscle contractility could be the consequence of continuous exposue of these cells to the NO of neuronal origin. These findings may help to better understand the physiology of NO in the gastrointestinal tract and the role that the "relaxin-NO" system plays in motor disorders such as functional bowel disease.
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MESH Headings
- Anesthetics, Local/pharmacology
- Animals
- Colon/blood supply
- Colon/cytology
- Colon/innervation
- Colon/metabolism
- Colon, Ascending/cytology
- Colon, Ascending/drug effects
- Colon, Ascending/innervation
- Colon, Ascending/metabolism
- Colon, Transverse/cytology
- Colon, Transverse/drug effects
- Colon, Transverse/innervation
- Colon, Transverse/metabolism
- Enzyme Inhibitors/pharmacology
- Female
- Guanylate Cyclase/antagonists & inhibitors
- In Vitro Techniques
- Interstitial Cells of Cajal/cytology
- Interstitial Cells of Cajal/drug effects
- Interstitial Cells of Cajal/metabolism
- Mechanical Phenomena
- Mice
- Mice, Inbred Strains
- Muscle Contraction/drug effects
- Muscle, Smooth/blood supply
- Muscle, Smooth/cytology
- Muscle, Smooth/innervation
- Muscle, Smooth/metabolism
- Nerve Tissue Proteins/antagonists & inhibitors
- Nerve Tissue Proteins/metabolism
- Neurons/cytology
- Neurons/drug effects
- Neurons/metabolism
- Nitric Oxide Donors/pharmacology
- Nitric Oxide Synthase Type I/antagonists & inhibitors
- Nitric Oxide Synthase Type I/metabolism
- Nitric Oxide Synthase Type III/antagonists & inhibitors
- Nitric Oxide Synthase Type III/metabolism
- Osmolar Concentration
- Relaxin/metabolism
- Submucous Plexus/cytology
- Submucous Plexus/drug effects
- Submucous Plexus/metabolism
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Affiliation(s)
- M C Baccari
- Department of Physiological Sciences, University of Florence, Florence, Italy
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