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Vignali S, Buhner S, Greiter W, Daniel H, Frieling T, Schemann M, Annahazi A. Biopsy samples from patients with irritable bowel syndrome, but not from those with mastocytosis or unspecific gastrointestinal complaints reveal unique nerve activation in all gut regions independent of mast cell density, histamine content or specific gastrointestinal symptoms. Front Neurosci 2024; 18:1291554. [PMID: 39015376 PMCID: PMC11250647 DOI: 10.3389/fnins.2024.1291554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 05/29/2024] [Indexed: 07/18/2024] Open
Abstract
Introduction We previously showed enteric nerve activation after application of colonic mucosal biopsy supernatants from patients with irritable bowel syndrome (IBS). The question remains whether this is a region-specific or a generalized sensitization. We tested the nerve-activating properties of supernatants from large and small intestinal regions of IBS patients with diarrhea (IBS-D) in comparison to those from mastocytosis patients with diarrhea (MC-D) or non-IBS/non-MC patients with GI-complaints. MC-D patients were included to test samples from patients with an established, severe mast cell disorder, because mast cells are suggested to play a role in IBS. Methods Voltage-sensitive dye imaging was used to record the effects of mucosal biopsy supernatants from IBS-D, MC-D, and non-IBS/non-MC on guinea pig submucous neurons. Mast cell density and histamine concentrations were measured in all samples. Results The median neuroindex (spike frequency × % responding neurons in Hz × %) was significantly (all p < 0.001) increased for IBS-D (duodenum and colon, proximal and distal each, 49.3; 50.5; 63.7; 71.9, respectively) compared to non-IBS/non-MC (duodenum and colon, proximal and distal each, 8.7; 4.9; 6.9; 5.4, respectively) or MC-D supernatants (duodenum and colon, proximal and distal each, 9.4; 11.9; 0.0; 7.9, respectively). Nerve activation by MC-D and non-IBS/non-MC supernatants was comparable (p>0.05). Mast cell density or histamine concentrations were not different between IBS-D, MC-D, and non-IBS/non-MC samples. Discussion Nerve activation by biopsy supernatants is an IBS hallmark that occurs throughout the gut, unrelated to mast cell density or histamine concentration. At least as important is our finding that GI complaints per se were not associated with biopsy supernatant-induced nerve activation, which further stresses the relevance of altered nerve behavior in IBS.
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Affiliation(s)
- Sheila Vignali
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Sabine Buhner
- Chair of Human Biology, Technical University of Munich, Freising, Germany
- Chair of Zoology, Technical University of Munich, Freising, Germany
| | - Wolfgang Greiter
- Chair of Human Biology, Technical University of Munich, Freising, Germany
- Chair of Zoology, Technical University of Munich, Freising, Germany
| | - Hannelore Daniel
- Chair of Nutrition Physiology, Technical University of Munich, Freising, Germany
| | - Thomas Frieling
- Medical Clinic II, Helios Klinikum Krefeld, Krefeld, Germany
| | - Michael Schemann
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Anita Annahazi
- Chair of Human Biology, Technical University of Munich, Freising, Germany
- Chair of Zoology, Technical University of Munich, Freising, Germany
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Annaházi A, Schemann M. Contribution of the Enteric Nervous System to Autoimmune Diseases and Irritable Bowel Syndrome. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:1-8. [PMID: 36587141 DOI: 10.1007/978-3-031-05843-1_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Anti-neuronal autoantibodies can lead to subacute gastrointestinal dysmotility, presenting with various symptoms typical of intestinal pseudoobstruction, achalasia, gastroparesis, or slow intestinal transit, among others. Such autoantibodies may be produced in response to a remote tumor and accelerate the diagnosis of malignancy, but in other cases they appear without an identifiable underlying cause. One example is the type I anti-neuronal nuclear antibody (ANNA-1 otherwise known as anti-Hu), which is usually linked to small cell-lung carcinoma. Anti-Hu can directly activate enteric neurons and visceral sensory nerve fibers and has a cytotoxic effect. Various other anti-neuronal antibodies have been described, targeting different ion channels or receptors on nerve cells of the central or the enteric nervous system. Autoimmune processes targeting enteric neurons may also play a role in more common disorders such as esophageal achalasia, celiac disease, or multiple sclerosis. Furthermore, anti-enteric neuronal antibodies have been found more abundant in the common functional gastrointestinal disorder, irritable bowel syndrome (IBS), than in controls. The pathogenesis of IBS is very complex, involving the release of various mediators from immune cells in the gut wall. Products of mast cells, such as histamine and tryptase, excite visceral afferents and enteric neurons, which may contribute to symptoms like abdominal pain and disturbed motility. Elevated serine- and cysteine-protease activity in stool of IBS-D and IBS-C patients, respectively, can be a factor leading to leaky gut and visceral hypersensitivity. More knowledge on these mediators in IBS may facilitate the development of novel diagnostic methods or therapies.
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Affiliation(s)
- Anita Annaházi
- Human Biology, Technical University of Munich, Freising, Germany
| | - Michael Schemann
- Human Biology, Technical University of Munich, Freising, Germany.
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do Carmo Neto JR, Braga YLL, da Costa AWF, Lucio FH, do Nascimento TC, dos Reis MA, Celes MRN, de Oliveira FA, Machado JR, da Silva MV. Biomarkers and Their Possible Functions in the Intestinal Microenvironment of Chagasic Megacolon: An Overview of the (Neuro)inflammatory Process. J Immunol Res 2021; 2021:6668739. [PMID: 33928170 PMCID: PMC8049798 DOI: 10.1155/2021/6668739] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 03/08/2021] [Accepted: 03/19/2021] [Indexed: 12/13/2022] Open
Abstract
The association between inflammatory processes and intestinal neuronal destruction during the progression of Chagasic megacolon is well established. However, many other components play essential roles, both in the long-term progression and control of the clinical status of patients infected with Trypanosoma cruzi. Components such as neuronal subpopulations, enteric glial cells, mast cells and their proteases, and homeostasis-related proteins from several organic systems (serotonin and galectins) are differentially involved in the progression of Chagasic megacolon. This review is aimed at revealing the characteristics of the intestinal microenvironment found in Chagasic megacolon by using different types of already used biomarkers. Information regarding these components may provide new therapeutic alternatives and improve the understanding of the association between T. cruzi infection and immune, endocrine, and neurological system changes.
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Affiliation(s)
- José Rodrigues do Carmo Neto
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, GO, Brazil
| | - Yarlla Loyane Lira Braga
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, GO, Brazil
| | - Arthur Wilson Florêncio da Costa
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, GO, Brazil
| | - Fernanda Hélia Lucio
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, GO, Brazil
| | - Thais Cardoso do Nascimento
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, GO, Brazil
| | - Marlene Antônia dos Reis
- Department of General Pathology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Mara Rubia Nunes Celes
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, GO, Brazil
| | - Flávia Aparecida de Oliveira
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, GO, Brazil
| | - Juliana Reis Machado
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, GO, Brazil
- Department of General Pathology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Marcos Vinícius da Silva
- Department of Microbiology, Immunology and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
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McClain JL, Mazzotta EA, Maradiaga N, Duque-Wilckens N, Grants I, Robison AJ, Christofi FL, Moeser AJ, Gulbransen BD. Histamine-dependent interactions between mast cells, glia, and neurons are altered following early-life adversity in mice and humans. Am J Physiol Gastrointest Liver Physiol 2020; 319:G655-G668. [PMID: 32996781 PMCID: PMC7792668 DOI: 10.1152/ajpgi.00041.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Early-life adversity contributes to the development of functional bowel disorders later in life through unresolved mechanisms. Here, we tested the hypothesis that early-life adversity alters anatomical and functional interactions between mast cells and enteric glia. The effects of early-life stress were studied using the neonatal maternal separation (NMS) stress mouse model. Anatomical relationships between mast cells and enteric glia were assessed using immunohistochemistry and mast cell reporter mice (Mcpt5Cre;GCaMP5g-tdT). Immunohistochemistry was used to assess the expression of histamine, histamine 1 (H1) receptors, and glial fibrillary acidic protein. Functional responses of glia to mast cell mediators were assessed in calcium imaging experiments using Sox10CreERT2;GCaMP5g-tdT mice and cultured human enteric glial cells. NMS increases mast cell numbers at the level of the myenteric plexus and their proximity to myenteric ganglia. Myenteric glia respond to mediators released by activated mast cells that are blocked by H1 receptor antagonists in mice and humans and by blocking neuronal activity with tetrodotoxin in mouse tissue. Histamine replicates the effects of mast cell supernatants on enteric glia, and NMS increases histamine production by mast cells. NMS reduces glial responses to mast cell mediators in mouse tissue, while potentiating responses in cultured human enteric glia. NMS increases myenteric glial fibrillary acidic protein expression and reduces glial process length but does not cause neurodegeneration. Histamine receptor expression is not altered by NMS and is localized to neurons in mice, but glia in humans. Early-life stress increases the potential for interactions between enteric glia and mast cells, and histamine is a potential mediator of mast cell-glial interactions through H1 receptors. We propose that glial-mast cell signaling is a mechanism that contributes to enteric neuroplasticity driven by early-life adversity.NEW & NOTEWORTHY Early-life adversity places an individual at risk for developing functional gastrointestinal disorders later in life through unknown mechanisms. Here, we show that interactions between mast cells and glia are disrupted by early-life stress in mice and that histamine is a potential mediator of mast cell-glial interactions.
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Affiliation(s)
- Jonathon L. McClain
- 1Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Elvio A. Mazzotta
- 2Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - Nidia Maradiaga
- 3Gastrointestinal Stress Biology Laboratory, Department Large Animal Clinical Sciences, Michigan State University, East Lansing, Michigan
| | - Natalia Duque-Wilckens
- 1Department of Physiology, Michigan State University, East Lansing, Michigan,3Gastrointestinal Stress Biology Laboratory, Department Large Animal Clinical Sciences, Michigan State University, East Lansing, Michigan
| | - Iveta Grants
- 2Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - Alfred J. Robison
- 1Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Fievos L. Christofi
- 2Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - Adam J. Moeser
- 1Department of Physiology, Michigan State University, East Lansing, Michigan,3Gastrointestinal Stress Biology Laboratory, Department Large Animal Clinical Sciences, Michigan State University, East Lansing, Michigan
| | - Brian D. Gulbransen
- 1Department of Physiology, Michigan State University, East Lansing, Michigan
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Desormeaux C, Bautzova T, Garcia-Caraballo S, Rolland C, Barbaro MR, Brierley SM, Barbara G, Vergnolle N, Cenac N. Protease-activated receptor 1 is implicated in irritable bowel syndrome mediators-induced signaling to thoracic human sensory neurons. Pain 2019; 159:1257-1267. [PMID: 29554016 DOI: 10.1097/j.pain.0000000000001208] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Proteases and protease-activated receptors (PARs) are major mediators involved in irritable bowel syndrome (IBS). Our objectives were to decipher the expression and functionality (calcium signaling) of PARs in human dorsal root ganglia (DRG) neurons and to define mechanisms involved in human sensory neuron signaling by IBS patient mediators. Human thoracic DRG were obtained from the national disease resource interchange. Expression of PAR1, PAR2, and PAR4 was assessed by immunohistochemistry and quantitative reverse transcription PCR (RT-qPCR) in whole DRG or in primary cultures of isolated neurons. Calcium signaling in response to PAR agonist peptides (PAR-AP), their inactive peptides (PAR-IP), thrombin (10 U/mL), supernatants from colonic biopsies of patients with IBS, or healthy controls, with or without PAR1 or PAR4 antagonist were studied in cultured human DRG neurons. PAR1, PAR2, and PAR4 were all expressed in human DRG, respectively, in 20%, 40%, and 40% of the sensory neurons. PAR1-AP increased intracellular calcium concentration in a dose-dependent manner. This increase was inhibited by PAR1 antagonism. By contrast, PAR2-AP, PAR4-AP, and PAR-IP did not cause calcium mobilization. PAR1-AP-induced calcium flux was significantly reduced by preincubation with PAR4-AP, but not with PAR2-AP. Thrombin increased calcium flux, which was inhibited by a PAR1 antagonist and increased by a PAR4 antagonist. Supernatants from colonic biopsies of patients with IBS induced calcium flux in human sensory neurons compared with healthy controls, and this induction was reversed by a PAR1 antagonist. Taken together, our results highlight that PAR1 antagonism should be investigated as a new therapeutic target for IBS symptoms.
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Affiliation(s)
- Cleo Desormeaux
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Tereza Bautzova
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Sonia Garcia-Caraballo
- Visceral Pain Group, Human Physiology, Flinders University, Bedford Park, South Australia, Australia.,Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Corinne Rolland
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | | | - Stuart M Brierley
- Visceral Pain Group, Human Physiology, Flinders University, Bedford Park, South Australia, Australia.,Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, University of Adelaide, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Giovanni Barbara
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Nathalie Vergnolle
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France.,Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary, Calgary, Canada
| | - Nicolas Cenac
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
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Tikoo S, Barki N, Jain R, Zulkhernain NS, Buhner S, Schemann M, Weninger W. Imaging of mast cells. Immunol Rev 2019; 282:58-72. [PMID: 29431206 DOI: 10.1111/imr.12631] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mast cells are a part of the innate immune system implicated in allergic reactions and the regulation of host-pathogen interactions. The distribution, morphology and biochemical composition of mast cells has been studied in detail in vitro and on tissue sections both at the light microscopic and ultrastructural level. More recently, the development of fluorescent reporter strains and intravital imaging modalities has enabled first glimpses of the real-time behavior of mast cells in situ. In this review, we describe commonly used imaging approaches to study mast cells in cell culture as well as within normal and diseased tissues. We further describe the interrogation of mast cell function via imaging by providing a detailed description of mast cell-nerve plexus interactions in the intestinal tract. Together, visualizing mast cells has expanded our view of these cells in health and disease.
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Affiliation(s)
- Shweta Tikoo
- The Centenary Institute, Newtown, NSW, Australia.,Discipline of Dermatology, Sydney Medical School, Sydney, NSW, Australia
| | - Natasja Barki
- LS Human Biology, Technical University München, München, Germany
| | - Rohit Jain
- The Centenary Institute, Newtown, NSW, Australia.,Discipline of Dermatology, Sydney Medical School, Sydney, NSW, Australia
| | | | - Sabine Buhner
- LS Human Biology, Technical University München, München, Germany
| | - Michael Schemann
- LS Human Biology, Technical University München, München, Germany
| | - Wolfgang Weninger
- The Centenary Institute, Newtown, NSW, Australia.,Discipline of Dermatology, Sydney Medical School, Sydney, NSW, Australia.,Department of Dermatology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
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Buhner S, Hahne H, Hartwig K, Li Q, Vignali S, Ostertag D, Meng C, Hörmannsperger G, Braak B, Pehl C, Frieling T, Barbara G, De Giorgio R, Demir IE, Ceyhan GO, Zeller F, Boeckxstaens G, Haller D, Kuster B, Schemann M. Protease signaling through protease activated receptor 1 mediate nerve activation by mucosal supernatants from irritable bowel syndrome but not from ulcerative colitis patients. PLoS One 2018. [PMID: 29529042 PMCID: PMC5846775 DOI: 10.1371/journal.pone.0193943] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background & aims The causes of gastrointestinal complaints in irritable bowel syndrome (IBS) remain poorly understood. Altered nerve function has emerged as an important pathogenic factor as IBS mucosal biopsy supernatants consistently activate enteric and sensory neurons. We investigated the neurally active molecular components of such supernatants from patients with IBS and quiescent ulcerative colitis (UC). Method Effects of supernatants from 7 healthy controls (HC), 20 IBS and 12 UC patients on human and guinea pig submucous neurons were studied with neuroimaging techniques. We identify differentially expressed proteins with proteome analysis. Results Nerve activation by IBS supernatants was prevented by the protease activated receptor 1 (PAR1) antagonist SCHE79797. UC supernatants also activated enteric neurons through protease dependent mechanisms but without PAR1 involvement. Proteome analysis of the supernatants identified 204 proteins, among them 17 proteases as differentially expressed between IBS, UC and HC. Of those the four proteases elastase 3a, chymotrypsin C, proteasome subunit type beta-2 and an unspecified isoform of complement C3 were significantly more abundant in IBS compared to HC and UC supernatants. Of eight proteases, which were upregulated in IBS, the combination of elastase 3a, cathepsin L and proteasome alpha subunit-4 showed the highest prediction accuracy of 98% to discriminate between IBS and HC groups. Elastase synergistically potentiated the effects of histamine and serotonin–the two other main neuroactive substances in the IBS supernatants. A serine protease inhibitor isolated from the probiotic Bifidobacterium longum NCC2705 (SERPINBL), known to inhibit elastase-like proteases, prevented nerve activation by IBS supernatants. Conclusion Proteases in IBS and UC supernatants were responsible for nerve activation. Our data demonstrate that proteases, particularly those signalling through neuronal PAR1, are biomarker candidates for IBS, and protease profiling may be used to characterise IBS.
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Affiliation(s)
- Sabine Buhner
- Human Biology, Technische Universität München, Freising, Germany
| | - Hannes Hahne
- Proteomics and Bioanalytics, Technische Universität München, Freising, Germany
| | - Kerstin Hartwig
- Human Biology, Technische Universität München, Freising, Germany
| | - Qin Li
- Human Biology, Technische Universität München, Freising, Germany
- Department of Physiology, Shangdong University, Shangdong, China
| | - Sheila Vignali
- Human Biology, Technische Universität München, Freising, Germany
| | - Daniela Ostertag
- Human Biology, Technische Universität München, Freising, Germany
| | - Chen Meng
- Proteomics and Bioanalytics, Technische Universität München, Freising, Germany
| | | | - Breg Braak
- Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands
| | | | | | - Giovanni Barbara
- Department of Medical and Surgical Sciences, St. Orsola Hospital, Bologna, Italy
| | - Roberto De Giorgio
- Department of Clinical Sciences, Nuovo Arcispedale S. Anna, University of Ferrara, Ferrara, Italy
| | - Ihsan Ekin Demir
- Department of General Surgery, University Hospital Rechts der Isar, Technische Universität München, Germany
| | - Güralp Onur Ceyhan
- Department of General Surgery, University Hospital Rechts der Isar, Technische Universität München, Germany
| | | | - Guy Boeckxstaens
- Translational Research Centre for Gastrointestinal Disorders, University Hospital Gasthuisberg, Catholic University of Leuven, Leuven, Belgium
| | - Dirk Haller
- Nutrition and Immunology, Technische Universität München, Freising, Germany
| | - Bernhard Kuster
- Proteomics and Bioanalytics, Technische Universität München, Freising, Germany
| | - Michael Schemann
- Human Biology, Technische Universität München, Freising, Germany
- * E-mail:
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Buhner S, Barki N, Greiter W, Giesbertz P, Demir IE, Ceyhan GO, Zeller F, Daniel H, Schemann M. Calcium Imaging of Nerve-Mast Cell Signaling in the Human Intestine. Front Physiol 2017; 8:971. [PMID: 29238306 PMCID: PMC5712982 DOI: 10.3389/fphys.2017.00971] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 11/14/2017] [Indexed: 12/12/2022] Open
Abstract
Introduction: It is suggested that an altered microenvironment in the gut wall alters communication along a mast cell nerve axis. We aimed to record for the first time signaling between mast cells and neurons in intact human submucous preparations. Methods: We used the Ca2+ sensitive dye Fluo-4 AM to simultaneously image changes in intracellular calcium [Ca+2]i (%ΔF/F) in neurons and mast cells. Data are presented as median with interquartile ranges (25/75%). Results: We recorded nerve responses in 29 samples upon selective activation of 223 mast cells by IgE receptor cross linking with the antibody mAb22E7. Mast cells responded to mAb22E7 with a median [Ca+2]i increase of 20% (11/39) peaking 90 s (64/144) after the application. Only very few neurons responded and the median percentage of responding neuronal area was 0% (0/5.9). Mast cell activation remained in the presence of the fast sodium channel blocker tetrodotoxin. Specific neuronal activation by transmural electrical field stimulation (EFS) in 34 samples evoked instantaneously [Ca+2]i signals in submucous neurons. This was followed by a [Ca+2]i peak response of 8%ΔF/F (4/15) in 33% of 168 mast cells in the field of view. The mast cell response was abolished by the nerve blocker tetrododoxin, reduced by the Calcitonin Gene-Related Peptide receptor 1 antagonist BIBN-4096 and the Vasoactive Intestinal Peptide receptor antagonist PG97-269, but not by blockade of the neurokinin receptors 1-3. Conclusion: The findings revealed bidirectional signaling between mast cells and submucous neurons in human gut. In our macroscopically normal preparations a nerve to mast cell signaling was very prominent whereas a mast cell to nerve signaling was rather rare.
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Affiliation(s)
- Sabine Buhner
- Human Biology, Technische Universität München, Freising, Germany
| | - Natasja Barki
- Human Biology, Technische Universität München, Freising, Germany
| | - Wolfgang Greiter
- Human Biology, Technische Universität München, Freising, Germany
| | - Pieter Giesbertz
- Molecular Nutrition Unit, Technische Universität München, Freising, Germany
| | - Ihsan E. Demir
- Department of General Surgery, University Hospital Rechts der Isar, Technische Universität München, Munich, Germany
| | - Güralp O. Ceyhan
- Department of General Surgery, University Hospital Rechts der Isar, Technische Universität München, Munich, Germany
| | | | - Hannelore Daniel
- Molecular Nutrition Unit, Technische Universität München, Freising, Germany
| | - Michael Schemann
- Human Biology, Technische Universität München, Freising, Germany
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