1
|
Patel M, Middleton JP, Goodkin HP, Barnes B, McGowan E, Eid R. Persistent Diarrhea and Eosinophilic Esophagitis Resulting From Chronic Cannabidiol Usage for Refractory Epilepsy. JPGN REPORTS 2022; 3:e253. [PMID: 37168471 PMCID: PMC10158314 DOI: 10.1097/pg9.0000000000000253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 05/25/2022] [Indexed: 05/13/2023]
Abstract
Cannabidiol is used in the care of treatment-resistant epilepsy. It has been associated with varying side effects, ranging from somnolence to diarrhea and weight loss. We present a patient on chronic cannabidiol therapy who had persistent diarrhea, abdominal pain, weight loss, and esophageal eosinophilia that improved with cannabidiol dose adjustment.
Collapse
Affiliation(s)
- Maitri Patel
- From the School of Medicine, University of Virginia, Charlottesville, VA
| | | | - Howard P. Goodkin
- Department of Neurology and Pediatrics, University of Virginia, Charlottesville, VA
| | - Barrett Barnes
- Division of Pediatric Gastroenterology, University of Virginia School of Medicine, Charlottesville, VA
| | - Emily McGowan
- Division of Allergy and Immunology, University of Virginia School of Medicine, Charlottesville, VA
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Ryan Eid
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD
| |
Collapse
|
2
|
Ozdener MH, Mahavadi S, Mummalaneni S, Lyall V. Relationship between ENaC Regulators and SARS-CoV-2 Virus Receptor (ACE2) Expression in Cultured Adult Human Fungiform (HBO) Taste Cells. Nutrients 2022; 14:2703. [PMID: 35807883 PMCID: PMC9268489 DOI: 10.3390/nu14132703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/21/2022] [Accepted: 06/26/2022] [Indexed: 12/04/2022] Open
Abstract
In addition to the α, β, and γ subunits of ENaC, human salt-sensing taste receptor cells (TRCs) also express the δ-subunit. At present, it is not clear if the expression and function of the ENaC δ-subunit in human salt-sensing TRCs is also modulated by the ENaC regulatory hormones and intracellular signaling effectors known to modulate salt responses in rodent TRCs. Here, we used molecular techniques to demonstrate that the G-protein-coupled estrogen receptor (GPER1), the transient receptor potential cation channel subfamily V member 1 (TRPV1), and components of the renin-angiotensin-aldosterone system (RAAS) are expressed in δ-ENaC-positive cultured adult human fungiform (HBO) taste cells. Our results suggest that RAAS components function in a complex with ENaC and TRPV1 to modulate salt sensing and thus salt intake in humans. Early, but often prolonged, symptoms of COVID-19 infection are the loss of taste, smell, and chemesthesis. The SARS-CoV-2 spike protein contains two subunits, S1 and S2. S1 contains a receptor-binding domain, which is responsible for recognizing and binding to the ACE2 receptor, a component of RAAS. Our results show that the binding of a mutated S1 protein to ACE2 decreases ACE2 expression in HBO cells. We hypothesize that changes in ACE2 receptor expression can alter the balance between the two major RAAS pathways, ACE1/Ang II/AT1R and ACE2/Ang-(1-7)/MASR1, leading to changes in ENaC expression and responses to NaCl in salt-sensing human fungiform taste cells.
Collapse
Affiliation(s)
| | - Sunila Mahavadi
- Department of Biology, Center for Biomedical Research, Tuskegee University, Tuskegee, AL 36088, USA;
| | - Shobha Mummalaneni
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA 23298, USA;
| | - Vijay Lyall
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA 23298, USA;
| |
Collapse
|
3
|
Woodland P, Shen Ooi JL, Grassi F, Nikaki K, Lee C, Evans JA, Koukias N, Triantos C, McDonald SA, Peiris M, Aktar R, Blackshaw LA, Sifrim D. Superficial Esophageal Mucosal Afferent Nerves May Contribute to Reflux Hypersensitivity in Nonerosive Reflux Disease. Gastroenterology 2017; 153:1230-1239. [PMID: 28734832 DOI: 10.1053/j.gastro.2017.07.017] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 07/12/2017] [Accepted: 07/13/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Little is known about the causes of heartburn in patients with gastro-esophageal reflux disease. Visible epithelial damage is seldom associated with symptom severity, evidenced by the significant symptom burden in patients with nonerosive reflux disease (NERD) compared with patients with erosive reflux disease (ERD) or Barrett's esophagus (BE). We studied the distribution of mucosal nerve fibers in patients with NERD, ERD, and BE, and compared the results with those of healthy subjects. METHODS We performed a prospective study of 13 patients with NERD, 11 patients with ERD, and 16 patients with BE undergoing endoscopic evaluation in the United Kingdom or Greece. Biopsies were obtained from the proximal and distal esophageal mucosa of patients with NERD, from the distal esophageal mucosa of patients with ERD, and the distal-most squamous epithelium of patients with BE. These were examined for the presence and location of nerve fibers that reacted with a labeled antibody against calcitonin gene-related peptide (CGRP), a marker of nociceptive sensory nerves. The results were compared with those from 10 healthy volunteers (controls). RESULTS The distribution of CGRP-positive nerves did not differ significantly between the distal esophageal mucosa of controls (median, 25.5 cell layers to surface; interquartile range [IQR], 21.4-28.8) vs patients with ERD (median, 23 cell layers to surface; IQR, 16-27.5), or patients with BE (median, 21.5 cell layers to surface; IQR, 16.1-27.5). However, CGRP-positive nerves were significantly more superficial in mucosa from patients with NERD-both distal (median, 9.5 cell layers to surface; IQR, 1.5-13.3; P < .0001 vs ERD, BE, and controls) and proximal (median, 5.0 cell layers to surface; IQR, 2.5-9.3 vs median 10.4 cell layers to surface; IQR, 8.0-16.9; P = .0098 vs controls). CONCLUSIONS Proximal and distal esophageal mucosa of patients with NERD have more superficial afferent nerves compared with controls or patients with ERD or BE. Acid hypersensitivity in patients with NERD might be partially explained by the increased proximity of their afferent nerves to the esophageal lumen, and therefore greater exposure to noxious substances in refluxate.
Collapse
Affiliation(s)
- Philip Woodland
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Joanne Li Shen Ooi
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Federica Grassi
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Kornilia Nikaki
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Chung Lee
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - James A Evans
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Nikolaos Koukias
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK; Department of Gastroenterology, University Hospital of Patras, Patras, Greece
| | - Christos Triantos
- Department of Gastroenterology, University Hospital of Patras, Patras, Greece
| | - Stuart A McDonald
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Madusha Peiris
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Rubina Aktar
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - L Ashley Blackshaw
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Daniel Sifrim
- Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
| |
Collapse
|
4
|
Allais L, De Smet R, Verschuere S, Talavera K, Cuvelier CA, Maes T. Transient Receptor Potential Channels in Intestinal Inflammation: What Is the Impact of Cigarette Smoking? Pathobiology 2016; 84:1-15. [DOI: 10.1159/000446568] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 05/02/2016] [Indexed: 11/19/2022] Open
|
5
|
Hudson ASR, Kunstetter AC, Damasceno WC, Wanner SP. Involvement of the TRPV1 channel in the modulation of spontaneous locomotor activity, physical performance and physical exercise-induced physiological responses. ACTA ACUST UNITED AC 2016; 49:e5183. [PMID: 27191606 PMCID: PMC4869825 DOI: 10.1590/1414-431x20165183] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/24/2016] [Indexed: 12/11/2022]
Abstract
Physical exercise triggers coordinated physiological responses to meet the augmented
metabolic demand of contracting muscles. To provide adequate responses, the brain
must receive sensory information about the physiological status of peripheral tissues
and organs, such as changes in osmolality, temperature and pH. Most of the receptors
involved in these afferent pathways express ion channels, including transient
receptor potential (TRP) channels, which are usually activated by more than one type
of stimulus and are therefore considered polymodal receptors. Among these TRP
channels, the TRPV1 channel (transient receptor potential vanilloid type 1 or
capsaicin receptor) has well-documented functions in the modulation of pain sensation
and thermoregulatory responses. However, the TRPV1 channel is also expressed in
non-neural tissues, suggesting that this channel may perform a broad range of
functions. In this review, we first present a brief overview of the available tools
for studying the physiological roles of the TRPV1 channel. Then, we present the
relationship between the TRPV1 channel and spontaneous locomotor activity, physical
performance, and modulation of several physiological responses, including water and
electrolyte balance, muscle hypertrophy, and metabolic, cardiovascular,
gastrointestinal, and inflammatory responses. Altogether, the data presented herein
indicate that the TPRV1 channel modulates many physiological functions other than
nociception and thermoregulation. In addition, these data open new possibilities for
investigating the role of this channel in the acute effects induced by a single bout
of physical exercise and in the chronic effects induced by physical training.
Collapse
Affiliation(s)
- A S R Hudson
- Escola de Educação Física, Fisioterapia e Terapia Ocupacional, Laboratório de Fisiologia do Exercício, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - A C Kunstetter
- Escola de Educação Física, Fisioterapia e Terapia Ocupacional, Laboratório de Fisiologia do Exercício, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - W C Damasceno
- Escola de Educação Física, Fisioterapia e Terapia Ocupacional, Laboratório de Fisiologia do Exercício, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - S P Wanner
- Escola de Educação Física, Fisioterapia e Terapia Ocupacional, Laboratório de Fisiologia do Exercício, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| |
Collapse
|
6
|
Abdel-Aziz H, Schneider M, Neuhuber W, Meguid Kassem A, Khailah S, Müller J, Gamal Eldeen H, Khairy A, T Khayyal M, Shcherbakova A, Efferth T, Ulrich-Merzenich G. GPR84 and TREM-1 Signaling Contribute to the Pathogenesis of Reflux Esophagitis. Mol Med 2016; 21:1011-1024. [PMID: 26650186 DOI: 10.2119/molmed.2015.00098] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 11/23/2015] [Indexed: 01/01/2023] Open
Abstract
Gastro-esophageal reflux disease (GERD) is one of the most common disorders in gastroenterology. Patients present with or without increased acid exposure indicating a nonuniform etiology. Thus, the common treatment with proton pump inhibitors (PPIs) fails to control symptoms in up to 40% of patients. To further elucidate the pathophysiology of the condition and explore new treatment targets, transcriptomics, proteomics and histological methods were applied to a surgically induced subchronic reflux esophagitis model in Wistar rats after treatment with either omeprazole (PPI) or STW5, a herbal preparation shown to ameliorate esophagitis without affecting refluxate pH. The normal human esophageal squamous cell line HET-1A and human endoscopic biopsies were used to confirm our findings to the G-protein-coupled receptor (GPR) 84 in human tissue. Both treatments reduced reflux-induced macroscopic and microscopic lesions of the esophagi as well as known proinflammatory cytokines. Proteomic and transcriptomic analyses identified CINC1-3, MIP-1/3α, MIG, RANTES and interleukin (IL)-1β as prominent mediators in GERD. Most regulated cyto-/chemokines are linked to the TREM-1 signaling pathway. The fatty acid receptor GPR84 was upregulated in esophagitis but significantly decreased in treated groups, a finding supported by Western blot and immunohistochemistry in both rat tissue and HET-1A cells. GPR84 was also found to be significantly upregulated in patients with grade B reflux esophagitis. The expression of GPR84 in esophageal tissue and its potential involvement in GERD are reported for the first time. IL-8 (CINC1-3) and the TREM-1 signaling pathway are proposed, besides GPR84, to play an important role in the pathogenesis of GERD.org.
Collapse
Affiliation(s)
- Heba Abdel-Aziz
- Department of Pharmacology, Institute of Pharmaceutical Chemistry, Westfalian Wilhelms University, Münster, Germany
| | - Mathias Schneider
- Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany
| | - Winfried Neuhuber
- Institute of Anatomy, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Abdel Meguid Kassem
- Tropical Medicine Department and Gastrointestinal Endoscopy Unit, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Saleem Khailah
- Tropical Medicine Department and Gastrointestinal Endoscopy Unit, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Jürgen Müller
- Scientific Department, Steigerwald Arzneimittelwerk GmbH, Darmstadt, Germany
| | - Hadeel Gamal Eldeen
- Tropical Medicine Department and Gastrointestinal Endoscopy Unit, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Ahmed Khairy
- Tropical Medicine Department and Gastrointestinal Endoscopy Unit, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Mohamed T Khayyal
- Department of Pharmacology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Anastasiia Shcherbakova
- Medical Clinic III, University Clinic Centre, Rheinische Friedrich-Wilhelms University, Bonn, Germany
| | - Thomas Efferth
- Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany
| | - Gudrun Ulrich-Merzenich
- Medical Clinic III, University Clinic Centre, Rheinische Friedrich-Wilhelms University, Bonn, Germany
| |
Collapse
|
7
|
Choi YJ, Kim N, Kim J, Lee DH, Park JH, Jung HC. Upregulation of Vanilloid Receptor-1 in Functional Dyspepsia With or Without Helicobacter pylori Infection. Medicine (Baltimore) 2016; 95:e3410. [PMID: 27175641 PMCID: PMC4902483 DOI: 10.1097/md.0000000000003410] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The etiological basis of functional dyspepsia (FD) is incompletely understood. The aim of this study was to evaluate the involvement of nociceptor-related genes and Helicobacter pylori (HP) in the pathogenesis of FD. The expression of nociceptor-related genes was measured in gastric cell lines that were co-cultured with HP. FD patients (n = 117) and controls (n = 55) were enrolled from a tertiary hospital gastroenterology clinic. Expression of the genes nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), and transient receptor potential cation channel subfamily V member 1 (TRPV1) in the gastric mucosa were detected by reverse transcription polymerase chain reaction (RT-PCR), and immunohistochemical staining of TRPV1 was analyzed. These measurements were repeated after 1 year. TRPV1, GDNF, and NGF expression was elevated in gastric cell lines co-cultured with HP. TRPV1 immunostaining was stronger in HP-positive than HP-negative subjects. The FD group showed higher expression levels of TRPV1, GDNF, and NGF and increased TRPV1 immunostaining compared with those of the control group (all P < 0.05). Among 61 subjects who were followed up at 1 year, controls with successful HP eradication and patients whose symptoms had improved both showed significant reductions in the expression of TRPV1 and NGF (all P < 0.05) compared with controls without HP eradication and patients whose symptoms had not improved, respectively. The expression of NGF, GDNF, and TRPV1 may be associated with the pathogenesis of FD. Since HP infection may induce the increased expression of these genes, anti-HP therapy could be beneficial for HP-positive patients with FD.
Collapse
Affiliation(s)
- Yoon Jin Choi
- From the Department of Internal Medicine and Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do (YJC, NK, DHL); and Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul (NK, JK, DHL, JHP, HCJ), South Korea
| | | | | | | | | | | |
Collapse
|
8
|
Gargus M, Niu C, Vallone JG, Binkley J, Rubin DC, Shaker A. Human esophageal myofibroblasts secrete proinflammatory cytokines in response to acid and Toll-like receptor 4 ligands. Am J Physiol Gastrointest Liver Physiol 2015; 308:G904-23. [PMID: 25882613 PMCID: PMC4451324 DOI: 10.1152/ajpgi.00333.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The pathophysiology of esophageal injury, repair, and inflammation in gastroesophageal reflux-disease (GERD) is complex. Whereas most studies have focused on the epithelial response to GERD injury, we are interested in the stromal response. We hypothesized that subepithelial esophageal myofibroblasts in GERD secrete proinflammatory cytokines in response to injurious agents encountered via epithelial barrier breaches or through dilated epithelial intercellular spaces. We determined the percentage of myofibroblasts [-smooth muscle actin (-SMA)+vimentin+CD31-] in the subepithelial GERD and normal esophageal stroma by immunomorphologic analysis. We performed -SMA coimmunostaining with IL-6 and p65. We established and characterized primary cultures of -SMA+vimentin+CD31-CD45- human esophageal myofibroblasts (HuEso MFs). We modeled GERD by treatment with pH 4.5-acidified media and Toll-like receptor 4 (TLR4) ligands, LPS and high-mobility group box 1 protein (HMGB1), and determined myofibroblast cytokine secretion in response to GERD injury. We demonstrate that spindle-shaped cell myofibroblasts are located near the basement membrane of stratified squamous epithelium in normal esophagus. We identify an increase in subepithelial myofibroblasts and activation of proinflammatory pathways in patients with GERD. Primary cultures of stromal cells obtained from normal esophagus retain myofibroblast morphology and express the acid receptor transient receptor potential channel vanilloid subfamily 1 (TRPV1) and TLR4. HuEso MFs stimulated with acid and TLR4 agonists LPS and HMGB1 increase IL-6 and IL-8 secretion via TRPV1 and NF-B activation. Our work implicates a role for human subepithelial stromal cells in the pathogenesis of GERD-related esophageal injury. Findings of this study can be extended to the investigation of epithelial-stromal interactions in inflammatory esophageal mucosal disorders.
Collapse
Affiliation(s)
- Matthew Gargus
- 1Department of Medicine, Keck School of Medicine of University of Southern California, Los Angeles, California;
| | - Chao Niu
- 1Department of Medicine, Keck School of Medicine of University of Southern California, Los Angeles, California;
| | - John G. Vallone
- 2Department of Pathology, Keck School of Medicine of University of Southern California, Los Angeles, California; and
| | - Jana Binkley
- 3Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri
| | - Deborah C. Rubin
- 3Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri
| | - Anisa Shaker
- 1Department of Medicine, Keck School of Medicine of University of Southern California, Los Angeles, California;
| |
Collapse
|
9
|
Abstract
Dramatic progress has been made over the past decade in the sophistication and availability of equipment to test esophageal motility and sensation. High-resolution esophageal manometry and impedance have moved from the research clinic into clinical practice. Some of the testing is costly and time consuming, and requires extensive experience to perform the testing and properly interpret the results. These sensory studies are valuable in the interpretation of clinical problems, and provide important research information. Clinicians should evaluate the research studies to advance their understanding of the pathophysiology of the esophagus.
Collapse
Affiliation(s)
- Salman Nusrat
- Section of Digestive Disease and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Philip B Miner
- Division of Gastroenterology, Department of Medicine, Oklahoma Foundation for Digestive Research, Oklahoma University School of Medicine, 525 Northwest 9th Street, Suite 325, Oklahoma City, OK 73102, USA.
| |
Collapse
|
10
|
Woodland P, Sifrim D, Krarup AL, Brock C, Frøkjaer JB, Lottrup C, Drewes AM, Swanstrom LL, Farmer AD. The neurophysiology of the esophagus. Ann N Y Acad Sci 2013; 1300:53-70. [DOI: 10.1111/nyas.12238] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Philip Woodland
- Neurogastroenterology Group, Barts and The London School of Medicine and Dentistry; Queen Mary University of London; London United Kingdom
| | - Daniel Sifrim
- Neurogastroenterology Group, Barts and The London School of Medicine and Dentistry; Queen Mary University of London; London United Kingdom
| | - Anne Lund Krarup
- Mech-Sense, Department of Gastroenterology; Aalborg Hospital; Aarhus University; Aarhus Denmark
| | - Christina Brock
- Mech-Sense, Department of Gastroenterology; Aalborg Hospital; Aarhus University; Aarhus Denmark
| | - Jens Brøndum Frøkjaer
- Mech-Sense, Department of Gastroenterology; Aalborg Hospital; Aarhus University; Aarhus Denmark
| | - Christian Lottrup
- Mech-Sense, Department of Gastroenterology; Aalborg Hospital; Aarhus University; Aarhus Denmark
| | - Asbjørn Mohr Drewes
- Mech-Sense, Department of Gastroenterology; Aalborg Hospital; Aarhus University; Aarhus Denmark
| | | | - Adam D. Farmer
- Department of Gastroenterology, Shrewsbury & Telford Hospitals NHS Trust; Princess Royal Hospital; Apley Castle Telford Shropshire United Kingdom
- Neurogastroenterology Group, Blizard Institute of Cell & Molecular Science; Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry; Queen Mary University of London; London United Kingdom
| |
Collapse
|
11
|
Ma J, Altomare A, Guarino M, Cicala M, Rieder F, Fiocchi C, Li D, Cao W, Behar J, Biancani P, Harnett KM. HCl-induced and ATP-dependent upregulation of TRPV1 receptor expression and cytokine production by human esophageal epithelial cells. AMERICAN JOURNAL OF PHYSIOLOGY. GASTROINTESTINAL AND LIVER PHYSIOLOGY 2012. [PMID: 22790593 DOI: 10.1152/ajpgi.00097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The pathogenesis of gastroesophageal reflux disease (GERD) remains elusive, but recent evidence suggests that early secretion of inflammatory cytokines and chemokines by the mucosa leads to influx of immune cells followed by tissue damage. We previously showed that exposure of esophageal mucosa to HCl causes ATP release, resulting in activation of acetyl-CoA:1-O-alkyl-sn-glycero-3-phosphocholine acetyltransferase (lyso-PAF AT), the enzyme responsible for the production of platelet-activating factor (PAF). In addition, HCl causes release of IL-8 from the esophageal mucosa. We demonstrate that esophageal epithelial cells secrete proinflammatory mediators in response to HCl and that this response is mediated by ATP. Monolayers of the human esophageal epithelial cell line HET-1A were exposed to acidified cell culture medium (pH 5) for 12 min, a total of seven times over 48 h, to simulate the recurrent acid exposure clinically occurring in GERD. HCl upregulated mRNA and protein expression for the acid-sensing transient receptor potential cation channel, subfamily vanilloid member 1 (TRPV1), lyso-PAF AT, IL-8, eotaxin-1, -2, and -3, macrophage inflammatory protein-1α, and monocyte chemoattractant protein-1. The chemokine profile secreted by HET-1A cells in response to repeated HCl exposure parallels similar findings in erosive esophagitis patients. In HET-1A cells, the TRPV1 agonist capsaicin reproduced these findings for mRNA of the inflammatory mediators lyso-PAF AT, IL-8, and eotaxin-1. These effects were blocked by the TRPV1 antagonists iodoresiniferatoxin and JNJ-17203212. These effects were imitated by direct application of ATP and blocked by the nonselective ATP antagonist suramin. We conclude that HCl/TRPV-induced ATP release upregulated secretion of various chemoattractants by esophageal epithelial cells. These chemoattractants are selective for leukocyte subsets involved in acute inflammatory responses and allergic inflammation. The data support the validity of HET-1A cells as a model of the response of the human esophageal mucosa in GERD.
Collapse
Affiliation(s)
- Jie Ma
- Department of Medicine, Rhode Island Hospital, Providence, Rhode Island, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Ma J, Altomare A, Guarino M, Cicala M, Rieder F, Fiocchi C, Li D, Cao W, Behar J, Biancani P, Harnett KM. HCl-induced and ATP-dependent upregulation of TRPV1 receptor expression and cytokine production by human esophageal epithelial cells. Am J Physiol Gastrointest Liver Physiol 2012; 303:G635-45. [PMID: 22790593 PMCID: PMC3468560 DOI: 10.1152/ajpgi.00097.2012] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The pathogenesis of gastroesophageal reflux disease (GERD) remains elusive, but recent evidence suggests that early secretion of inflammatory cytokines and chemokines by the mucosa leads to influx of immune cells followed by tissue damage. We previously showed that exposure of esophageal mucosa to HCl causes ATP release, resulting in activation of acetyl-CoA:1-O-alkyl-sn-glycero-3-phosphocholine acetyltransferase (lyso-PAF AT), the enzyme responsible for the production of platelet-activating factor (PAF). In addition, HCl causes release of IL-8 from the esophageal mucosa. We demonstrate that esophageal epithelial cells secrete proinflammatory mediators in response to HCl and that this response is mediated by ATP. Monolayers of the human esophageal epithelial cell line HET-1A were exposed to acidified cell culture medium (pH 5) for 12 min, a total of seven times over 48 h, to simulate the recurrent acid exposure clinically occurring in GERD. HCl upregulated mRNA and protein expression for the acid-sensing transient receptor potential cation channel, subfamily vanilloid member 1 (TRPV1), lyso-PAF AT, IL-8, eotaxin-1, -2, and -3, macrophage inflammatory protein-1α, and monocyte chemoattractant protein-1. The chemokine profile secreted by HET-1A cells in response to repeated HCl exposure parallels similar findings in erosive esophagitis patients. In HET-1A cells, the TRPV1 agonist capsaicin reproduced these findings for mRNA of the inflammatory mediators lyso-PAF AT, IL-8, and eotaxin-1. These effects were blocked by the TRPV1 antagonists iodoresiniferatoxin and JNJ-17203212. These effects were imitated by direct application of ATP and blocked by the nonselective ATP antagonist suramin. We conclude that HCl/TRPV-induced ATP release upregulated secretion of various chemoattractants by esophageal epithelial cells. These chemoattractants are selective for leukocyte subsets involved in acute inflammatory responses and allergic inflammation. The data support the validity of HET-1A cells as a model of the response of the human esophageal mucosa in GERD.
Collapse
Affiliation(s)
- Jie Ma
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island; ,2School of Pharmaceutical Sciences, Jilin University, Changchun, Jilin, China;
| | - Annamaria Altomare
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island; ,3Department of Digestive Disease of Campus Bio Medico University of Rome, Rome, Italy;
| | - Michele Guarino
- 3Department of Digestive Disease of Campus Bio Medico University of Rome, Rome, Italy;
| | - Michele Cicala
- 3Department of Digestive Disease of Campus Bio Medico University of Rome, Rome, Italy;
| | - Florian Rieder
- 4Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio; and
| | - Claudio Fiocchi
- 4Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio; and
| | - Dan Li
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Weibiao Cao
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island; ,5Department of Pathology, Rhode Island Hospital and Brown University, Providence, Rhode Island
| | - Jose Behar
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Piero Biancani
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Karen M. Harnett
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| |
Collapse
|
13
|
Ma J, Altomare A, Rieder F, Behar J, Biancani P, Harnett KM. ATP: a mediator for HCl-induced TRPV1 activation in esophageal mucosa. Am J Physiol Gastrointest Liver Physiol 2011; 301:G1075-82. [PMID: 21960521 PMCID: PMC3233789 DOI: 10.1152/ajpgi.00336.2011] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In esophageal mucosa, HCl causes TRPV1-mediated release of calcitonin gene-related peptide (CGRP) and substance P (SP) from submucosal neurons and of platelet-activating factor (PAF) from epithelial cells. CGRP and SP release was unaffected by PAF antagonists but reduced by the purinergic antagonist suramin. ATP caused CGRP and SP release from esophageal mucosa, confirming a role of ATP in the release. The human esophageal epithelial cell line HET-1A was used to identify epithelial cells as the site of ATP release. HCl caused ATP release from HET-1A, which was reduced by the TRPV1 antagonist 5-iodoresiniferatoxin. Real-time PCR demonstrated the presence of mRNA for several P2X and P2Y purinergic receptors in epithelial cells. HCl also increased activity of lyso-PAF acetyl-CoA transferase (lyso-PAF AT), the enzyme responsible for production of PAF. The increase was blocked by suramin. ATP caused a similar increase, confirming ATP as a mediator for the TRPV1-induced increase in enzyme activity. Repeated exposure of HET-1A cells to HCl over 2 days caused upregulation of mRNA and protein expression for lyso-PAF AT. Suramin blocked this response. Repeated exposure to ATP caused a similar mRNA increase, confirming ATP as a mediator for upregulation of the enzyme. Thus, HCl-induced activation of TRPV1 causes ATP release from esophageal epithelial cells that causes release of CGRP and SP from esophageal submucosal neurons and activation of lyso-PAF AT, the enzyme responsible for the production of PAF in epithelial cells. Repeated application of HCl or of ATP causes upregulation of lyso-PAF AT in epithelial cells.
Collapse
Affiliation(s)
- Jie Ma
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island; ,2School of Pharmaceutical Sciences, Jilin University , Changchun, Jilin, China;
| | - Annamaria Altomare
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island; ,3Department of Digestive Disease of Campus Bio Medico University of Rome, Rome, Italy; and
| | - Florian Rieder
- 4Departments of Pathobiology, Lerner Research Institute, and Gastroenterology and Hepatology, Digestive Disease Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Jose Behar
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Piero Biancani
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Karen M. Harnett
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| |
Collapse
|
14
|
Abstract
Gastroesophageal reflux disease (GERD) affects 20-30% of the population in Western countries, and is one of the most common clinical problems in daily practice. GERD-associated functional and structural abnormalities are caused by recurrent exposure of the esophagus to acidic and nonacidic refluxate of gastric contents (containing duodenal and intestinal proteases as well as acid and gastric pepsin) from the stomach. Major progress has been made in the understanding of the molecular pathogenesis of GERD-associated mucosal inflammation, suggesting a complex and multifactorial pathogenesis and immune-mediated effects. This Review summarizes the complexity of mucosal pathogenesis, including microscopic changes, mucosal inflammation and GERD-specific molecular mediators, in the context of the clinical features and pathophysiological characteristics of GERD. The abnormal exposure of the esophagus to luminal contents leads to chronic mucosal inflammation that is characterized by the release of IL-8 specifically, as well as other proinflammatory mediators, from the esophageal mucosa. Evidence from animal studies indicates a stepwise inflammatory response by the epithelium, which attracts immune effector cells to infiltrate the mucosa. From bench to bedside, these novel molecular findings might provide new treatment options beyond current acid-suppressive therapy and the principle of inhibition of transient lower esophageal sphincter relaxation.
Collapse
|
15
|
Orlando RC, Paterson WG, Harnett KM, Ma J, Behar J, Biancani P, Guarino MPL, Altomare A, Cicala M, Cao W. Esophageal disease: updated information on inflammation. Ann N Y Acad Sci 2011; 1232:369-75. [PMID: 21950828 DOI: 10.1111/j.1749-6632.2011.06064.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The following on esophageal disease provides updated information the mucosal defense against acid and acid-pepsin injury; the roles of platelet activating factor, mast cells, proinflammatory cytokines, and chemokines in inflammation; differences and similarities in erosive and nonerosive esophagitis; acid and vanilloid receptors in esophageal mucosa; and bile acid receptors in esophageal epithelium.
Collapse
Affiliation(s)
- Roy C Orlando
- Gastroenterology, Cell, and Molecular Physiology, University of North Carolina School of Medicine at Chapel Hill, Chapel Hill, North Carolina, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Shikano M, Ueda T, Kamiya T, Ishida Y, Yamada T, Mizushima T, Shimura T, Mizoshita T, Tanida S, Kataoka H, Shimada S, Ugawa S, Joh T. Acid inhibits TRPV4-mediated Ca²⁺ influx in mouse esophageal epithelial cells. Neurogastroenterol Motil 2011; 23:1020-8, e497. [PMID: 21883699 DOI: 10.1111/j.1365-2982.2011.01767.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The transient receptor potential vanilloid 4 (TRPV4), a thermo-sensitive stretch-activated cation channel, is expressed in the skin stratified squamous epithelium, contributing to the acquisition of barrier function. Similarly, functional TRPV4 may be located in the stratified squamous epithelial lining of the esophagus, being involved in the pathogenesis of gastroesophageal reflux disease (GERD). Here we investigated the expression of TRPV4 in the mouse esophageal epithelium. METHODS TRPV4 expression at the mRNA and protein levels was examined by reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemistry. A calcium imaging technique and ATP assay were used to evaluate the functionality of TRPV4 in freshly isolated esophageal epithelial cells. KEY RESULTS Transcripts and proteins encoding TRPV4 were colocalized in the basal and intermediate layers of the esophageal epithelium. Both 4α-phorbol 12,13- didecanoate (4α-PDD), a selective agonist for TRPV4, and hypo-osmolar solution (160 mOsm) elevated the intracellular calcium concentration ([Ca(2+) ](i) ) in a subset of the isolated cells (70%). These [Ca(2+) ](i) increases were potently inhibited by ruthenium red (RuR), a TRPV4 channel antagonist, and were suppressed by extracellular protons (pH 5.0). Finally, application of 4α-PDD evoked ATP release in primary esophageal epithelial cells. CONCLUSIONS & INFERENCES Acid-sensitive TRPV4 channels were mainly expressed in the esophageal epithelial cells of the basal and intermediate layers. Direct exposure of TRPV4-expressing cells to gastric acid, as would occur in cases of GERD, could influence their cellular functions, possibly aggravating the disease state.
Collapse
Affiliation(s)
- M Shikano
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Holzer P. Transient receptor potential (TRP) channels as drug targets for diseases of the digestive system. Pharmacol Ther 2011; 131:142-70. [PMID: 21420431 PMCID: PMC3107431 DOI: 10.1016/j.pharmthera.2011.03.006] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 12/12/2022]
Abstract
Approximately 20 of the 30 mammalian transient receptor potential (TRP) channel subunits are expressed by specific neurons and cells within the alimentary canal. They subserve important roles in taste, chemesthesis, mechanosensation, pain and hyperalgesia and contribute to the regulation of gastrointestinal motility, absorptive and secretory processes, blood flow, and mucosal homeostasis. In a cellular perspective, TRP channels operate either as primary detectors of chemical and physical stimuli, as secondary transducers of ionotropic or metabotropic receptors, or as ion transport channels. The polymodal sensory function of TRPA1, TRPM5, TRPM8, TRPP2, TRPV1, TRPV3 and TRPV4 enables the digestive system to survey its physical and chemical environment, which is relevant to all processes of digestion. TRPV5 and TRPV6 as well as TRPM6 and TRPM7 contribute to the absorption of Ca²⁺ and Mg²⁺, respectively. TRPM7 participates in intestinal pacemaker activity, and TRPC4 transduces muscarinic acetylcholine receptor activation to smooth muscle contraction. Changes in TRP channel expression or function are associated with a variety of diseases/disorders of the digestive system, notably gastro-esophageal reflux disease, inflammatory bowel disease, pain and hyperalgesia in heartburn, functional dyspepsia and irritable bowel syndrome, cholera, hypomagnesemia with secondary hypocalcemia, infantile hypertrophic pyloric stenosis, esophageal, gastrointestinal and pancreatic cancer, and polycystic liver disease. These implications identify TRP channels as promising drug targets for the management of a number of gastrointestinal pathologies. As a result, major efforts are put into the development of selective TRP channel agonists and antagonists and the assessment of their therapeutic potential.
Collapse
Affiliation(s)
- Peter Holzer
- Research Unit of Translational Neurogastroenterology, Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Universitätsplatz 4, A-8010 Graz, Austria.
| |
Collapse
|
18
|
Harnett KM, Rieder F, Behar J, Biancani P. Viewpoints on Acid-induced inflammatory mediators in esophageal mucosa. J Neurogastroenterol Motil 2010; 16:374-88. [PMID: 21103419 PMCID: PMC2978390 DOI: 10.5056/jnm.2010.16.4.374] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2010] [Revised: 08/18/2010] [Accepted: 08/21/2010] [Indexed: 12/13/2022] Open
Abstract
We have focused on understanding the onset of gastroesophageal reflux disease by examining the mucosal response to the presence of acid in the esophageal lumen. Upon exposure to HCl, inflammation of the esophagus begins with activation of the transient receptor potential channel vanilloid subfamily member-1 (TRPV1) in the mucosa, and production of IL-8, substance P (SP), calcitonin gene related peptide (CGRP) and platelet activating factor (PAF). Production of SP and CGRP, but not PAF, is abolished by the neural blocker tetrodotoxin suggesting that SP and CGRP are neurally released and that PAF arises from non neural pathways. Epithelial cells contain TRPV1 receptor mRNA and protein and respond to HCl and to the TRPV1 agonist capsaicin with production of PAF. PAF, SP and IL-8 act as chemokines, inducing migration of peripheral blood leukocytes. PAF and SP activate peripheral blood leukocytes inducing the production of H2O2. In circular muscle, PAF causes production of IL-6, and IL-6 causes production of additional H2O2, through activation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases. Among these, NADPH oxidase 5 cDNA is significantly up-regulated by exposure to PAF; H2O2 content of esophageal and lower esophageal sphincter circular muscle is elevated in human esophagitis, causing dysfunction of esophageal circular muscle contraction and reduction in esophageal sphincter tone. Thus esophageal keratinocytes, that constitute the first barrier to the refluxate, may also serve as the initiating cell type in esophageal inflammation, secreting inflammatory mediators and pro-inflammatory cytokines and affecting leukocyte recruitment and activity.
Collapse
Affiliation(s)
- Karen M Harnett
- Department of Medicine, Rhode Island Hospital and Brown University, Providence, RI, USA
| | | | | | | |
Collapse
|
19
|
Ma J, Altomare A, de la Monte S, Tong M, Rieder F, Fiocchi C, Behar J, Shindou H, Biancani P, Harnett KM. HCl-induced inflammatory mediators in esophageal mucosa increase migration and production of H2O2 by peripheral blood leukocytes. Am J Physiol Gastrointest Liver Physiol 2010; 299:G791-8. [PMID: 20616304 PMCID: PMC2950690 DOI: 10.1152/ajpgi.00160.2010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Exposure of esophageal mucosa to hydrochloric acid (HCl) is a crucial factor in the pathogenesis of reflux disease. We examined supernatant of HCl-exposed rabbit mucosa for inflammatory mediators enhancing migration of leukocytes and production of H(2)O(2) as an indicator of leukocyte activation. A tubular segment of rabbit esophageal mucosa was tied at both ends to form a sac, which was filled with HCl-acidified Krebs buffer at pH 5 (or plain Krebs buffer as control) and kept oxygenated at 37 degrees C. The medium around the sac (supernatant) was collected after 3 h. Rabbit peripheral blood leukocytes (PBL) were isolated, and sac supernatant was used to investigate PBL migration and H(2)O(2) production. HCl-exposed esophageal mucosa released substance P (SP), CGRP, platelet-activating factor (PAF), and IL-8 into the supernatant. PBL migration increased in response to IL-8 or to supernatant of the HCl-filled mucosal sac. Supernatant-induced PBL migration was inhibited by IL-8 antibodies and by antagonists for PAF (CV3988) or neurokinin 1 (i.e., SP), but not by a CGRP antagonist. Supernatant of the HCl-filled mucosal sac increased H(2)O(2) release by PBL that was significantly reduced by CV3988 and by a SP antagonist but was not affected by IL-8 antibodies or by a CGRP antagonist. We conclude that IL-8, PAF, and SP are important inflammatory mediators released by esophageal mucosa in response to acid that promote PBL migration. In addition, PAF and SP induce production of H(2)O(2) by PBL. These findings provide a direct link between acid exposure and recruitment and activation of immune cells in esophageal mucosa.
Collapse
Affiliation(s)
- Jie Ma
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island; ,2School of Pharmaceutical Sciences, Jilin University, Changchun, Jilin, China;
| | - Annamaria Altomare
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island; ,3Department of Digestive Disease of Campus Bio Medico University of Rome, Rome, Italy;
| | - Suzanne de la Monte
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Ming Tong
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Florian Rieder
- 4Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio; and
| | - Claudio Fiocchi
- 4Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio; and
| | - Jose Behar
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Hideo Shindou
- 5Department of Biochemistry and Molecular Biology, University of Tokyo, Tokyo, Japan
| | - Piero Biancani
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Karen M. Harnett
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| |
Collapse
|