Genomes and Genes
MECHANOTRANSDUCTION IN INTESTINAL SMOOTH MUSCLE CELLS
Principal Investigator: Gianrico Farrugia
Abstract: DESCRIPTION (provided by applicant): Ion channels are required to generate electrical activity that drives contractility in organs such as the gastrointestinal tract and the heart. In previous grant cycles we have shown that human small intestinal smooth muscle cells (SMC) express a voltage-sensitive Na+ channel, Nav1.5, the a subunit of which is encoded by SCN5A and that Nav1.5 is mechanosensitive. Mechano-regulation of Nav1.5 is highly relevant because of the steep voltage-sensitivity, with small changes in channel kinetics markedly affecting physiology. Nav1.5 is selectively expressed. It generates a Na+ current in the intestinal tract of humans, dogs and rats but not in several other species such as guinea pig and mouse. Mutations in Nav1.5 cause disease. The central hypothesis of this proposal is that mechanosensitivity of the Nav1.5 is due to physical changes in the voltage sensor(s), and that physiologically relevant mechanical stimuli markedly alter Nav1.5 function. We also hypothesize that in a subset of patients with irritable bowel syndrome (IBS), specific mutations in SCN5A result in altered electrophysiology and mechanosensitivity of Nav1.5 and that Nav1.5 regulates membrane potential and Ca2+ dynamics of human SMC. We will test the central hypothesis in 3 specific aims. In SA 1 we will determine the basic mechanisms that underlie ion channel mechanosensitivity. In SA 2 we will determine the physiological relevance of Nav1.5 mutations found in IBS. In SA 3 we will determine the physiological role of Nav1.5. The specific aims are supported by preliminary data which show that SCN5A mutations are found in approximately 3% of patients with IBS (over 1.35 million), that IBS SCN5A mutations change the electrophysiology of Nav1.5, that mutants and toxins modulate mechanosensitivity, that mechanosensitivity can also be modulated by FDA approved drugs, that knockdown and pharmacological block of Nav1.5 hyperpolarize human intestinal circular SMC membrane potential and change slow wave frequency, that Nav1.5 is clustered on the cell membrane and that Na+ entry through Nav1.5 sets local intracellular Na+ and regulates Ca2+ through Na+/Ca2+ exchanger (NCX). We will use patch clamp techniques, ultrafast pressure delivery, high resolution patch imaging, immunohistochemistry, Western blots, single cell PCR, quantitative PCR, lentivirus RNA knock down techniques, organotypic and single cell cultures, total internal reflection fluorescence (TIRF) imaging of proteins, Ca2+ and Na+ as well as microelectrode recordings to investigate the central hypothesis. Successful completion of the proposed studies has both basic significance and clinical impact. As a result of the work done in the previous grant cycles and the preliminary data presented in this proposal, we are now poised to significantly advance our understanding, at a sub- molecular level, of the fundamental mechanisms that underlie mechanosensitivity, of the role Nav1.5 plays in normal and abnormal human intestinal physiology and to establish a role of ion channelopathies in a subset of patients with IBS.
Funding Period: 1997-09-01 - 2016-08-31
more information: NIH RePORT
- Effect of modulation of serotonergic, cholinergic, and nitrergic pathways on murine fundic size and compliance measured by ultrasonomicrometryLin Xue
Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, 200 First St SW, Rochester, MN 55905, USA
Am J Physiol Gastrointest Liver Physiol 290:G74-82. 2006..The data suggest that ultrasonomicrometry is a useful tool that can reproducibly and accurately measure changes in fundic size and the response to pharmacological agents...
- Targeting ion channels for the treatment of gastrointestinal motility disordersArthur Beyder
Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
Therap Adv Gastroenterol 5:5-21. 2012..Rational drug design can come from an integrated view of the structure and mechanisms of gating and activation by voltage or mechanical stress...
- Ranolazine decreases mechanosensitivity of the voltage-gated sodium ion channel Na(v)1.5: a novel mechanism of drug actionArthur Beyder
Division of Gastroenterology and Hepatology, Enteric Neuroscience Program, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
Circulation 125:2698-706. 2012..Ranolazine is a Na(V)1.5 antagonist with antianginal and antiarrhythmic properties...
- Membrane permeable local anesthetics modulate Na(V)1.5 mechanosensitivityArthur Beyder
Division of Gastroenterology and Hepatology, Enteric Neuroscience Program, Mayo Clinic, Rochester, MN, USA
Channels (Austin) 6:308-16. 2012..Modulation of Na(V)1.5 mechanosensitivity by the membrane permeable local anesthetics may require hydrophobic access and may involve membrane-protein interactions...
- Ranolazine inhibits shear sensitivity of endogenous Na+ current and spontaneous action potentials in HL-1 cellsPeter Strege
Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
Channels (Austin) 6:457-62. 2012..Inhibition of the frequency and decay rate of action potentials in HL-1 cells are potential mechanisms behind the antiarrhythmic effect of ranolazine...
- Distribution of TMEM100 in the mouse and human gastrointestinal tract--a novel marker of enteric nervesS T Eisenman
Enteric Neuroscience Program, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905, USA
Neuroscience 240:117-28. 2013..The expression of TMEM100 in the enteric nervous system may reflect a role in the development and differentiation of cells through a transforming growth factor β, BMP or related signaling pathway...
- Detection of anticonductive tissue autoantibodies in a patient with chronic intestinal pseudo-obstruction and sick sinus syndromeGiacomo Caio
aDepartment of Medical and Surgical Sciences Digestive Diseases and Internal Medicine, St Orsola Malpighi Hospital bDepartment of Medical and Veterinary Sciences, University of Bologna, Bologna cDepartment of Internal Medicine, Division of Cardiology, San Giovanni Battista Hospital, University of Turin, Turin, Italy dEnteric NeuroScience Program, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
Eur J Gastroenterol Hepatol 25:1358-63. 2013..The severe gut and heart (likely autoimmune-mediated) dysfunction presented in this case provides a basis to further assess a link between intestinal and cardiac abnormal rhythmicity. ..
- Loss-of-function of the voltage-gated sodium channel NaV1.5 (channelopathies) in patients with irritable bowel syndromeArthur Beyder
Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
Gastroenterology 146:1659-68. 2014..5. Many patients with cardiac arrhythmias caused by mutations in SCN5A also have symptoms of irritable bowel syndrome (IBS). We investigated whether patients with IBS have SCN5A variants that affect the function of NaV1.5...
- Inhaled carbon monoxide attenuates myocardial inflammatory cytokine expression in a rat model of cardiopulmonary bypassJuan N Pulido
Department of Anesthesiology, Mayo Clinic College of Medicine, Saint Mary s Hospital, Rochester, Minnesota 55905, USA
J Extra Corpor Technol 43:137-43. 2011..Further investigation in a survival model of CPB is warranted...
- Quantification of gastrointestinal sodium channelopathyYong Cheng Poh
Division of Bioengineering, National University of Singapore, 9 Engineering Drive 1, Block EA 03 12 Singapore 117576, Singapore
J Theor Biol 293:41-8. 2012..Thus, the R76C mutation was sufficient to alter ICC and SMC cell electrophysiology. However, the cause-effect relationship between R76C and intestinal pseudo-obstruction remains an open question...
- A stochastic multi-scale model of electrical function in normal and depleted ICC networksJerry Gao
Auckland Bioengineering Institute, The University of Auckland, Auckland 1010, New Zealand
IEEE Trans Biomed Eng 58:3451-5. 2011..The modified SNESIM algorithm can be used with simulation techniques to quantify the physiological consequences of ICC network depletion at various physical scales...
- Enteric autoantibodies and gut motility disordersPurna Kashyap
Mayo Clinic, Rochester, MN 55905, USA
Gastroenterol Clin North Am 37:397-410, vi-vii. 2008..Algorithms are suggested for the work-up and treatment of patients with circulating antibodies associated with gastrointestinal motility disorders...
- The alpha1H Ca2+ channel subunit is expressed in mouse jejunal interstitial cells of Cajal and myocytesSimon J Gibbons
Enteric Neuroscience Program, Mayo Clinic College of Medicine, Rochester, MN, USA
J Cell Mol Med 13:4422-31. 2009..Furthermore, the survival of mice that do not express the alpha(1H) Ca(2+) channel protein is dependent on the genetic background and targeting approach used to generate the knockout mice...
- Neural autoantibody profile of primary achalasiaRobert E Kraichely
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
Dig Dis Sci 55:307-11. 2010..5% in control subjects), in the absence of diabetes or companion antibodies predictive of type 1 diabetes. This profile of autoantibodies suggests an autoimmune basis for a subset of primary achalasia...
- T-type Ca(2+) channel modulation by otilonium bromidePeter R Strege
Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, USA
Am J Physiol Gastrointest Liver Physiol 298:G706-13. 2010..This may represent a new mechanism of action for antispasmodics and may contribute to the observed increased clinical effectiveness of antispasmodics compared with selective L-type Ca(2+) channel blockers...
- Mechanosensitivity of Nav1.5, a voltage-sensitive sodium channelArthur Beyder
Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
J Physiol 588:4969-85. 2010..These data suggest that mechanical activation of Na(v)1.5 results in dose-dependent voltage dependence shifts of activation and inactivation due to mechanical modulation of the voltage sensors...
- Altered expression of Ano1 variants in human diabetic gastroparesisAmelia Mazzone
Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
J Biol Chem 286:13393-403. 2011..Changes in Ano1 expression in ICC may directly contribute to diabetic gastroparesis...
- Hydrogen sulfide is a partially redox-independent activator of the human jejunum Na+ channel, Nav1.5Peter R Strege
Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, USA
Am J Physiol Gastrointest Liver Physiol 300:G1105-14. 2011..5 peak current. These studies show that H(2)S activates the gastrointestinal Na(+) channel, and the mechanism of action of H(2)S is partially redox independent...
- Biophysically based modeling of the interstitial cells of cajal: current status and future perspectivesRachel Lees-Green
Auckland Bioengineering Institute, The University of Auckland Auckland, New Zealand
Front Physiol 2:29. 2011..The review concludes by examining several potential clinical applications of biophysically based ICC modeling from the subcellular through to the organ level, including ion channelopathies and ICC network degradation...
- Carbon monoxide, hydrogen sulfide, and nitric oxide as signaling molecules in the gastrointestinal tractGianrico Farrugia
Enteric Neuroscience Program, Division of Gastroenterology and Hepatology and Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota Electronic address
Gastroenterology 147:303-13. 2014..We review their signaling functions in the luminal gastrointestinal tract and discuss how their pathways interact. We also describe other physiological functions of CO and H2S and how they might be used as therapeutic agents. ..
- CARDIOVASCULAR DYNAMICS AND THEIR CONTROLJohn E Hall; Fiscal Year: 2013..End of Abstract) ..
- Rebuilding the Failing HeartPiero Anversa; Fiscal Year: 2013..abstract_text> ..
- Voltage-Dependent Ion Channel GatingRoderick MacKinnon; Fiscal Year: 2013..An in-depth understanding of the atomic structure and mechanisms of voltage- dependent ion channels holds promise for new approaches in the future to treat diseases such as epilepsy and cardiac arrhythmia. ..
- Mechanisms of PMN and Endothelial-Mediated Lung Inflammation and InjuryAsrar B Malik; Fiscal Year: 2013..abstract_text> ..
- Endophenotypes of Sleep Apnea and Role of ObesityALLAN IAN PACK; Fiscal Year: 2013..It will lead to a new molecular signature of OSA that could transform the practice of medicine in this area in a new, cost-effective way. ..
- CARDIAC ENERGY METABOLISM IN HEART FAILUREHani N Sabbah; Fiscal Year: 2013..In addition, there will be four Cores (Administrative, Large Animal/Histology, Metabolism, and Mitochondria/Mass Spec). ..
- Calcium signaling in the cerebrovascular unit in health and diseaseMark T Nelson; Fiscal Year: 2013..The long-term objective is to understand blood flow in the brain in health and disease, and by doing so, to reveal exciting novel targets that can be exploited in the treatment of cerebrovascular disease. ..
- Molecular motors in cell biologyYale E Goldman; Fiscal Year: 2013..We anticipate that the proposed work will take us significantly further toward our goal of understanding motility in the normal and pathological function of cells. ..
- CALCIUM DYNAMICS IN INTERSTITIAL CELLS OF CAJALGianrico Farrugia; Fiscal Year: 2013..Our work also has broad implications beyond the GI tract. As Ano-1 is expressed in many organs and tumors including gastrointestinal stromal tumors, our findings will likely apply to several other organs outside of the GI tract. ..
- Gastointestinal Hormone Research Core CenterChung Owyang; Fiscal Year: 2013..abstract_text> ..
- STRUCTURAL STUDIES ON PROKARYOTIC POTASSIUM CHANNELSAdrian Gross; Fiscal Year: 2013..Determining the precise structure and mechanism of action of these channels will allow for the development of safer and more effective drugs. ..
- KCNQ Channels and Vasoconstrictor Signal TransductionKenneth L Byron; Fiscal Year: 2013....
- Signaling Processes Underlying Cardiovascular FunctionJeffrey Robbins; Fiscal Year: 2013..These projects are supported by 3 Cores: Core A: The Administrative Core;Core B: The Physiology Core and Core C: The Imaging-Cell Culture Core. (End of Abstract) ..
- Vermont Center on Behavior and HealthStephen T Higgins; Fiscal Year: 2013..S. public health. ..
- Making Sense of Voltage SensorsStephen H White; Fiscal Year: 2013..His work focuses directly on the molecular basis of voltage sensor domains and their interactions with VSD-blocking toxins...
- Excitability of afferents evoking the exercise pressor reflexVictor Ruiz-Velasco; Fiscal Year: 2013..Likewise, in muscles, whose arteries are narrowed by disease, exercise can cause excessive stimulation of the sensory nerves that reflexively activate the sympathetic nervous system muscle pain (i.e., claudication). ..
- IPF Fibroblast PhenotypeCraig A Henke; Fiscal Year: 2013..A major objective of this Program Project is to inform decisions of the IPF Clinical Network by providing information that can be translated into novel therapeutic strategies for IPF. ..
- MINNESOTA OBESITY CENTERAllen S Levine; Fiscal Year: 2013..Resources for oilot/feasibilitv proiects and an educational program will be established. ..
- Rocky Mountain Regional Center of Excellence or Biodefense and Emerging InfectiouJohn T Belisle; Fiscal Year: 2013..abstract_text> ..
- INTEGRATED MECHANISMS OF CARDIAC MALADAPTATIONR John Solaro; Fiscal Year: 2013..Studies proposed here offer the potential for novel diagnostic procedures early in the progression of the disorders, and targets for novel therapies. (End of Abstract) ..
- Strategies for Improved Shock Wave LithotripsyJAMES ALEXANDER MCATEER; Fiscal Year: 2013..and the session can be ended * Determine the mechanism by which cavitation within a vessel causes hemorrhage * Develop numerical models to understand the role of cavitation and non-cavitational mechanisms in causing tissue damage ..