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Decraecker L, Boeckxstaens G, Denadai-Souza A. Inhibition of Serine Proteases as a Novel Therapeutic Strategy for Abdominal Pain in IBS. Front Physiol 2022; 13:880422. [PMID: 35665224 PMCID: PMC9161638 DOI: 10.3389/fphys.2022.880422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/26/2022] [Indexed: 02/06/2023] Open
Abstract
Serine proteases are heavily present in the gastrointestinal tract where they are essential in numerous physiological processes. An imbalance in the proteolytic activity is a central mechanism underlying abdominal pain in irritable bowel syndrome (IBS). Therefore, protease inhibitors are emerging as a promising therapeutic tool to manage abdominal pain in this functional gastrointestinal disorder. With this review, we provide an up-to-date overview of the implications of serine proteases in the development of abdominal pain in IBS, along with a critical assessment of the current developments and prospects of protease inhibitors as a therapeutic tool. In particular, we highlight the current knowledge gap concerning the identity of dysregulated serine proteases that are released by the rectal mucosa of IBS patients. Finally, we suggest a workflow with state-of-the-art techniques that will help address the knowledge gap, guiding future research towards the development of more effective and selective protease inhibitors to manage abdominal pain in IBS.
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De bruyn M, Ceuleers H, Hanning N, Berg M, De Man JG, Hulpiau P, Hermans C, Stenman UH, Koistinen H, Lambeir AM, De Winter BY, De Meester I. Proteolytic Cleavage of Bioactive Peptides and Protease-Activated Receptors in Acute and Post-Colitis. Int J Mol Sci 2021; 22:10711. [PMID: 34639054 PMCID: PMC8509398 DOI: 10.3390/ijms221910711] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 12/16/2022] Open
Abstract
The protease activity in inflammatory bowel disease (IBD) and irritable bowel syndrome has been studied extensively using synthetic fluorogenic substrates targeting specific sets of proteases. We explored activities in colonic tissue from a 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis rat model by investigating the cleavage of bioactive peptides. Pure trypsin- and elastase-like proteases on the one hand and colonic tissue from rats with TNBS-induced colitis in the acute or post-inflammatory phase on the other, were incubated with relevant peptides to identify their cleavage pattern by mass spectrometry. An increased cleavage of several peptides was observed in the colon from acute colitis rats. The tethered ligand (TL) sequences of peptides mimicking the N-terminus of protease-activated receptors (PAR) 1 and 4 were significantly unmasked by acute colitis samples and these cleavages were positively correlated with thrombin activity. Increased cleavage of β-endorphin and disarming of the TL-sequence of the PAR3-based peptide were observed in acute colitis and linked to chymotrypsin-like activity. Increased processing of the enkephalins points to the involvement of proteases with specificities different from trypsin- or chymotrypsin-like enzymes. In conclusion, our results suggest thrombin, chymotrypsin-like proteases and a set of proteases with different specificities as potential therapeutic targets in IBD.
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Affiliation(s)
- Michelle De bruyn
- Laboratory of Medical Biochemistry, University of Antwerp, 2610 Wilrijk, Belgium; (M.D.b.); (A.-M.L.)
- Infla-Med, Centre of Excellence, University of Antwerp, 2610 Wilrijk, Belgium; (H.C.); (N.H.); (M.B.); (J.G.D.M.); (B.Y.D.W.)
| | - Hannah Ceuleers
- Infla-Med, Centre of Excellence, University of Antwerp, 2610 Wilrijk, Belgium; (H.C.); (N.H.); (M.B.); (J.G.D.M.); (B.Y.D.W.)
- Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, 2610 Wilrijk, Belgium
| | - Nikita Hanning
- Infla-Med, Centre of Excellence, University of Antwerp, 2610 Wilrijk, Belgium; (H.C.); (N.H.); (M.B.); (J.G.D.M.); (B.Y.D.W.)
- Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, 2610 Wilrijk, Belgium
| | - Maya Berg
- Infla-Med, Centre of Excellence, University of Antwerp, 2610 Wilrijk, Belgium; (H.C.); (N.H.); (M.B.); (J.G.D.M.); (B.Y.D.W.)
| | - Joris G. De Man
- Infla-Med, Centre of Excellence, University of Antwerp, 2610 Wilrijk, Belgium; (H.C.); (N.H.); (M.B.); (J.G.D.M.); (B.Y.D.W.)
- Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, 2610 Wilrijk, Belgium
| | - Paco Hulpiau
- Bioinformatics Knowledge Center (BiKC), Howest University of Applied Sciences, 8000 Bruges, Belgium; (P.H.); (C.H.)
| | - Cedric Hermans
- Bioinformatics Knowledge Center (BiKC), Howest University of Applied Sciences, 8000 Bruges, Belgium; (P.H.); (C.H.)
| | - Ulf-Håkan Stenman
- Department of Clinical Chemistry and Haematology, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, Finland; (U.-H.S.); (H.K.)
| | - Hannu Koistinen
- Department of Clinical Chemistry and Haematology, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, Finland; (U.-H.S.); (H.K.)
| | - Anne-Marie Lambeir
- Laboratory of Medical Biochemistry, University of Antwerp, 2610 Wilrijk, Belgium; (M.D.b.); (A.-M.L.)
- Infla-Med, Centre of Excellence, University of Antwerp, 2610 Wilrijk, Belgium; (H.C.); (N.H.); (M.B.); (J.G.D.M.); (B.Y.D.W.)
| | - Benedicte Y. De Winter
- Infla-Med, Centre of Excellence, University of Antwerp, 2610 Wilrijk, Belgium; (H.C.); (N.H.); (M.B.); (J.G.D.M.); (B.Y.D.W.)
- Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, 2610 Wilrijk, Belgium
- Department of Gastroenterology and Hepatology, Antwerp University Hospital (UZA), 2650 Edegem, Belgium
| | - Ingrid De Meester
- Laboratory of Medical Biochemistry, University of Antwerp, 2610 Wilrijk, Belgium; (M.D.b.); (A.-M.L.)
- Infla-Med, Centre of Excellence, University of Antwerp, 2610 Wilrijk, Belgium; (H.C.); (N.H.); (M.B.); (J.G.D.M.); (B.Y.D.W.)
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A Survey of Methodologies for Assessing Mast Cell Density and Activation in Patients with Functional Abdominal Pain Disorders. GASTROINTESTINAL DISORDERS 2021. [DOI: 10.3390/gidisord3040016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The aim was to assess methods utilized in assessing mast cell involvement in functional abdominal pain disorders (FAPDs), specifically to describe variability in methods utilized to assess both mast cell density and activation and determine if a consensus exists. After a literature search identified 70 manuscripts assessing mast cell density, data were extracted including FAPD diagnosis, site of biopsy, selection of microscopic fields analyzed, selection of mucosal region analyzed, method of mast cell identification, method to assess mast cell density, and if performed, method to assess mast cell activation. There appears to be some consensus favoring inmmunohistochemical stains over histochemical stains for identifying mast cells. Otherwise, considerable variability exists in methodology for assessing mast cell density and activation. Regardless of method, approximately 80% of studies found increased mast cell density and/or activation in comparison to controls with no method being superior. A wide variety of methods have been employed to assess mast cell density and activation with no well-established consensus and inadequate data to recommend specific approaches. The current methodology providing physiologic information needs to be translated to a standard methodology providing clinical information with the development of criteria establishing abnormal density and/or activation, and more importantly, predicting treatment response.
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Choo J, Heo G, Pothoulakis C, Im E. Posttranslational modifications as therapeutic targets for intestinal disorders. Pharmacol Res 2021; 165:105412. [PMID: 33412276 DOI: 10.1016/j.phrs.2020.105412] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/14/2020] [Accepted: 12/22/2020] [Indexed: 02/08/2023]
Abstract
A variety of biological processes are regulated by posttranslational modifications. Posttranslational modifications including phosphorylation, ubiquitination, glycosylation, and proteolytic cleavage, control diverse physiological functions in the gastrointestinal tract. Therefore, a better understanding of their implications in intestinal diseases, including inflammatory bowel disease, irritable bowel syndrome, celiac disease, and colorectal cancer would provide a basis for the identification of novel biomarkers as well as attractive therapeutic targets. Posttranslational modifications can be common denominators, as well as distinct biomarkers, characterizing pathological differences of various intestinal diseases. This review provides experimental evidence that identifies changes in posttranslational modifications from patient samples, primary cells, or cell lines in intestinal disorders, and a summary of carefully selected information on the use of pharmacological modulators of protein modifications as therapeutic options.
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Affiliation(s)
- Jieun Choo
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea
| | - Gwangbeom Heo
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea
| | - Charalabos Pothoulakis
- Section of Inflammatory Bowel Disease & Inflammatory Bowel Disease Center, Division of Digestive Diseases, David Geffen School of Medicine, UCLA, Los Angeles, CA, 90095, USA
| | - Eunok Im
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea.
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Aguilera-Lizarraga J, Florens MV, Van Brussel T, Clevers E, Van Oudenhove L, Lambrechts D, Wouters MM, Boeckxstaens GE. Expression of immune-related genes in rectum and colon descendens of Irritable Bowel Syndrome patients is unrelated to clinical symptoms. Neurogastroenterol Motil 2019; 31:e13579. [PMID: 30854791 DOI: 10.1111/nmo.13579] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/06/2019] [Accepted: 02/07/2019] [Indexed: 12/18/2022]
Abstract
BACKGROUND Mucosal immune activation has been postulated to play an important role in the pathogenesis of irritable bowel syndrome (IBS). However, data are conflicting and often based on small patient cohorts. Here, we aimed to evaluate the gene expression of a large set of immune-related genes in mucosal biopsies from IBS patients and healthy volunteers (HV). METHODS A total of 171 IBS patients and 127 HV were included in the study. Rectum biopsies were collected from a cohort of 70 HV and 77 IBS patients (Rome III) and colon descendens biopsies from another cohort of 57 HV and 94 IBS patients (Rome II). Gene expression was assessed using OpenArray technology, and validated questionnaires were used to evaluate clinical characteristics (GI symptoms, somatization, anxiety, and depression). KEY RESULTS A subset of IBS patients (33%) with increased immune activation in the colon descendens was identified using multivariate analysis and displayed increased gene expression of IL1B (3-fold change), prostaglandin synthase PTGS2 (2.1-fold change), and the G-protein-coupled receptor MRGPRX2 (10.7-fold change). Clinical characteristics in this subgroup were however similar to the rest of the patient cohort. Analysis of rectal biopsies failed to identify such subgroup of "immuno-active" IBS patients in the other patient cohort. CONCLUSION A subset of IBS patients reveals evidence of immune activation in the colon descendens, but not in the rectum; however, gene expression is unrelated to clinical symptoms. To what extent this subgroup might however respond to anti-inflammatory therapy remains to be investigated.
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Affiliation(s)
- Javier Aguilera-Lizarraga
- Laboratory of Intestinal Neuroimmune Interactions, Department of Chronic Diseases, Metabolism and Ageing, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
| | - Morgane V Florens
- Laboratory of Intestinal Neuroimmune Interactions, Department of Chronic Diseases, Metabolism and Ageing, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
| | - Thomas Van Brussel
- Laboratory of Translational Genetics, Department of Oncology, KU Leuven, Leuven, Belgium.,Laboratory of Translational Genetics, Vesalius Research Center, VIB, Leuven, Belgium
| | - Egbert Clevers
- Laboratory of Brain-Gut Axis Studies, Department of Chronic Diseases, Metabolism and Ageing, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium.,Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lukas Van Oudenhove
- Laboratory of Brain-Gut Axis Studies, Department of Chronic Diseases, Metabolism and Ageing, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
| | - Diether Lambrechts
- Laboratory of Translational Genetics, Department of Oncology, KU Leuven, Leuven, Belgium.,Laboratory of Translational Genetics, Vesalius Research Center, VIB, Leuven, Belgium
| | - Mira M Wouters
- Laboratory of Intestinal Neuroimmune Interactions, Department of Chronic Diseases, Metabolism and Ageing, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
| | - Guy E Boeckxstaens
- Laboratory of Intestinal Neuroimmune Interactions, Department of Chronic Diseases, Metabolism and Ageing, Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
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Sung TS, Lu H, Sung J, Yeom JH, Perrino BA, Koh SD. The functional role of protease-activated receptors on contractile responses by activation of Ca 2+ sensitization pathways in simian colonic muscles. Am J Physiol Gastrointest Liver Physiol 2018; 315:G921-G931. [PMID: 30260688 PMCID: PMC6336947 DOI: 10.1152/ajpgi.00255.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
It has been known that activation of protease-activated receptors (PARs) affects gastrointestinal motility. In this study, we tested the effects of PAR agonists on electrical and contractile responses and Ca2+ sensitization pathways in simian colonic muscles. The Simian colonic muscle was initially hyperpolarized by PAR agonists. After the transient hyperpolarization, simian colonic muscle repolarized to the control resting membrane potential (RMP) without a delayed depolarization. Apamin significantly reduced the initial hyperpolarization, suggesting that activation of small conductance Ca2+-activated K+ (SK) channels is involved in the initial hyperpolarization. In contractile experiments, PAR agonists caused an initial relaxation followed by an increase in contractions. These delayed contractile responses were not matched with the electrical responses that showed no after depolarization of the RMP. To investigate the possible involvement of Rho-associated protein kinase 2 (ROCK) pathways in the PAR effects, muscle strips were treated with ROCK inhibitors, which significantly reduced the PAR agonist-induced contractions. Furthermore, PAR agonists increased MYPT1 phosphorylation, and ROCK inhibitors completely blocked MYPT1 phosphorylation. PAR agonists alone had no effect on CPI-17 phosphorylation. In the presence of apamin, PAR agonists significantly increased CPI-17 phosphorylation, which was blocked by protein kinase C (PKC) inhibitors suggesting that Ca2+ influx is increased by apamin and is activating PKC. In conclusion, these studies show that PAR activators induce biphasic responses in simian colonic muscles. The initial inhibitory responses by PAR agonists are mainly mediated by activation of SK channels and delayed contractile responses are mainly mediated by the CPI-17 and ROCK Ca2+ sensitization pathways in simian colonic muscles. NEW & NOTEWORTHY In the present study, we found that the contractile responses of simian colonic muscles to protease-activated receptor (PAR) agonists are different from the previously reported contractile responses of murine colonic muscles. Ca2+ sensitization pathways mediate the contractile responses of simian colonic muscles to PAR agonists without affecting the membrane potential. These findings emphasize novel mechanisms of PAR agonist-induced contractions possibly related to colonic dysmotility in inflammatory bowel disease.
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Affiliation(s)
- Tae Sik Sung
- 1Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
| | - Hongli Lu
- 2Department of Physiology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Juno Sung
- 1Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
| | - Jong Hoon Yeom
- 3Department of Anesthesiology and Pain Medicine, Hanyang University, Seoul, Republic of Korea
| | - Brian A. Perrino
- 1Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
| | - Sang Don Koh
- 1Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
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Lazaridis N, Germanidis G. Current insights into the innate immune system dysfunction in irritable bowel syndrome. Ann Gastroenterol 2018; 31:171-187. [PMID: 29507464 PMCID: PMC5825947 DOI: 10.20524/aog.2018.0229] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/22/2017] [Indexed: 12/12/2022] Open
Abstract
Irritable bowel syndrome (IBS) is a functional bowel disorder associated with abdominal pain and alterations in bowel habits. The presence of IBS greatly impairs patients' quality of life and imposes a high economic burden on the community; thus, there is intense pressure to reveal its elusive pathogenesis. Many etiological mechanisms have been implicated, but the pathophysiology of the syndrome remains unclear. As a result, novel drug development has been slow and no pharmacological intervention is universally accepted. A growing evidence implicates the role of low-grade inflammation and innate immune system dysfunction, although contradictory results have frequently been presented. Mast cells (MC), eosinophils and other key immune cells together with their mediators seem to play an important role, at least in subgroups of IBS patients. Cytokine imbalance in the systematic circulation and in the intestinal mucosa may also characterize IBS presentation. Toll-like receptors and their emerging role in pathogen recognition have also been highlighted recently, as dysregulation has been reported to occur in patients with IBS. This review summarizes the current knowledge regarding the involvement of any immunological alteration in the development of IBS. There is substantial evidence to support innate immune system dysfunction in several IBS phenotypes, but additional studies are required to better clarify the underlying pathogenetic pathways. IBS heterogeneity could potentially be attributed to multiple causes that lead to different disease phenotypes, thus explaining the variability found between study results.
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Affiliation(s)
- Nikolaos Lazaridis
- Gastroenterology Department, AHEPA University General Hospital of Thessaloniki, Thessaloniki, Greece
| | - Georgios Germanidis
- Gastroenterology Department, AHEPA University General Hospital of Thessaloniki, Thessaloniki, Greece
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Bashashati M, Moossavi S, Cremon C, Barbaro MR, Moraveji S, Talmon G, Rezaei N, Hughes PA, Bian ZX, Choi CH, Lee OY, Coëffier M, Chang L, Ohman L, Schmulson MJ, McCallum RW, Simren M, Sharkey KA, Barbara G. Colonic immune cells in irritable bowel syndrome: A systematic review and meta-analysis. Neurogastroenterol Motil 2018; 30. [PMID: 28851005 DOI: 10.1111/nmo.13192] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 07/26/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Increases in mucosal immune cells have frequently been observed in irritable bowel syndrome (IBS) patients. However, this finding is not completely consistent between studies, possibly due to a combination of methodological variability, population differences and small sample sizes. We performed a meta-analysis of case-control studies that compared immune cell counts in colonic biopsies of IBS patients and controls. METHODS PubMed and Embase were searched in February 2017. Results were pooled using standardized mean difference (SMD) and were considered significant when zero was not within the 95% confidence interval (CI). Heterogeneity was assessed based on I2 statistics where I2 ≤ 50% and I2 > 50% indicated fixed and random effect models, respectively. KEY RESULTS Twenty-two studies on 706 IBS patients and 401 controls were included. Mast cells were increased in the rectosigmoid (SMD: 0.38 [95% CI: 0.06-0.71]; P = .02) and descending colon (SMD: 1.69 [95% CI: 0.65-2.73]; P = .001) of IBS patients. Increased mast cells were observed in both constipation (IBS-C) and diarrhea predominant IBS (IBS-D). CD3+ T cells were increased in the rectosigmoid (SMD: 0.53 [95% CI: 0.21-0.85]; P = .001) and the descending colon of the IBS patients (SMD: 0.79, 95% CI [0.28-1.30]; P = .002). This was possibly in relation to higher CD4+ T cells in IBS (SMD: 0.33 [95% CI: 0.01-0.65]; P = .04) as there were no differences in CD8+ T cells. CONCLUSIONS & INFERENCES Mast cells and CD3+ T cells are increased in colonic biopsies of patients with IBS vs non-inflamed controls. These changes are segmental and sometimes IBS-subtype dependent. The diagnostic value of the quantification of colonic mucosal cells in IBS requires further investigation.
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Affiliation(s)
- M Bashashati
- Division of Gastroenterology, Department of Internal Medicine, Texas Tech University Health Sciences Center/Paul L. Foster School of Medicine, El Paso, TX, USA
| | - S Moossavi
- Digestive Oncology Research Center, Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran
- Department of Medical Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - C Cremon
- Department of Medical and Surgical Sciences, Centre for Applied Biomedical Research, University of Bologna, Bologna, Italy
| | - M R Barbaro
- Department of Medical and Surgical Sciences, Centre for Applied Biomedical Research, University of Bologna, Bologna, Italy
| | - S Moraveji
- Division of Gastroenterology, Department of Internal Medicine, Texas Tech University Health Sciences Center/Paul L. Foster School of Medicine, El Paso, TX, USA
| | - G Talmon
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
- Fred and Pamela Buffet Cancer Center, Omaha, NE, USA
| | - N Rezaei
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - P A Hughes
- Centre for Nutritional and Gastrointestinal Diseases, Department of Medicine, University of Adelaide and South Australian Health Medical Health Research Institute, Adelaide, SA, Australia
| | - Z X Bian
- School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - C H Choi
- Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea
| | - O Y Lee
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea
| | - M Coëffier
- Normandie Univ, INSERM unit 1073 "Nutrition, inflammation and brain-gut axis", Institute for Research and Innovation in Biomedicine, Rouen Medical University and Rouen University Hospital, Rouen, France
| | - L Chang
- G Oppenheimer Center of Neurobiology of Stress and Resilience, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - L Ohman
- Departments of Internal Medicine and Clinical Nutrition and Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - M J Schmulson
- Laboratorio de Hígado, Páncreas y Motilidad (HIPAM), Unidad de Investigación en Medicina Experimental, Facultad de Medicina-Universidad Nacional Autónoma de México (UNAM), Hospital General de México, Mexico City, Mexico
| | - R W McCallum
- Division of Gastroenterology, Department of Internal Medicine, Texas Tech University Health Sciences Center/Paul L. Foster School of Medicine, El Paso, TX, USA
| | - M Simren
- Department of Internal Medicine & Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Center for Functional GI and Motility Disorders, University of North Carolina, Chapel Hill, NC, USA
| | - K A Sharkey
- Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - G Barbara
- Department of Medical and Surgical Sciences, Centre for Applied Biomedical Research, University of Bologna, Bologna, Italy
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Liang WJ, Zhang G, Luo HS, Liang LX, Huang D, Zhang FC. Tryptase and Protease-Activated Receptor 2 Expression Levels in Irritable Bowel Syndrome. Gut Liver 2017; 10:382-90. [PMID: 26446924 PMCID: PMC4849691 DOI: 10.5009/gnl14319] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Background/Aims Previous studies have revealed that mast cells (MCs) may activate the protease-activated receptors and release of neuropeptides involved in the pathogenesis of irritable bowel syndrome (IBS). The levels of protease-activated receptor 2 (PAR-2) and tryptase can contribute to understanding the pathogenesis of IBS. Methods Colonoscopic biopsies were performed of 38 subjects (20 with IBS-diarrhea [IBS-D], eight with IBS-constipation [IBS-C], and 10 healthy volunteers). The mRNA and protein levels of tryptase and PAR-2 were assessed by real-time PCR and Western blot. The levels of vasoactive intestinal peptide (VIP), substance P (SP), and calcitonin gene-related peptide (CGRP) were measured by immunohistochemistry, and MCs were counted by toluidine blue staining. Results Significant increases in the mRNA expression of tryptase (p<0.05, IBS-D, IBS-C vs control) and PAR-2 (p<0.05, IBS-D, IBS-C vs control) and in the tryptase protein level (p<0.05, IBS-D, IBS-C vs control) were detected in IBS. Elevations of MCs, CGRP, VIP and SP (p<0.05, IBS-D vs control) were observed for IBS-D only. Conclusions Tryptase levels may upregulate the function of PAR-2, resulting in the release of neuropeptide and they were correlated with clinical symptoms associated with IBS.
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Affiliation(s)
- Wen-Jing Liang
- Department of Gastroenterology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Guo Zhang
- Department of Gastroenterology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - He-Sheng Luo
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Lie-Xin Liang
- Department of Gastroenterology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Dan Huang
- Department of Gastroenterology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Fa-Can Zhang
- Department of Gastroenterology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
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段 园, 唐 旭, 王 凤, 马 祥. PAR-2信号通路与功能性胃肠病. Shijie Huaren Xiaohua Zazhi 2017; 25:1159-1165. [DOI: 10.11569/wcjd.v25.i13.1159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
功能性胃肠病(functional gastrointestinal disorders, FGIDs)是一组排除器质性病变的胃肠道疾病, 其症状复杂且无特异性. 该类疾病在人群中患病率不断升高, 虽不致死, 但伴随精神症状大大降低了患者生活质量, 病情反复且周期长, 给患者家庭和社会造成了一定经济压力. 探索其发病机制以制定更佳治疗策略成为当前重任. 近年研究证实蛋白酶激活受体2(protease-activated receptor 2, PAR-2)在FGIDs发病机制中的作用确切, 相关研究亦越来越深入. 但众多研究各持一角, 不免混杂, 故本文就近几年PAR-2的相关研究作了梳理, 以便后续研究能有所借鉴, 看到不足, 并能做进一步的深入研究.
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Ceuleers H, Van Spaendonk H, Hanning N, Heirbaut J, Lambeir AM, Joossens J, Augustyns K, De Man JG, De Meester I, De Winter BY. Visceral hypersensitivity in inflammatory bowel diseases and irritable bowel syndrome: The role of proteases. World J Gastroenterol 2016; 22:10275-10286. [PMID: 28058009 PMCID: PMC5175241 DOI: 10.3748/wjg.v22.i47.10275] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/10/2016] [Accepted: 12/02/2016] [Indexed: 02/06/2023] Open
Abstract
Proteases, enzymes catalyzing the hydrolysis of peptide bonds, are present at high concentrations in the gastrointestinal tract. Besides their well-known role in the digestive process, they also function as signaling molecules through the activation of protease-activated receptors (PARs). Based on their chemical mechanism for catalysis, proteases can be classified into several classes: serine, cysteine, aspartic, metallo- and threonine proteases represent the mammalian protease families. In particular, the class of serine proteases will play a significant role in this review. In the last decades, proteases have been suggested to play a key role in the pathogenesis of visceral hypersensitivity, which is a major factor contributing to abdominal pain in patients with inflammatory bowel diseases and/or irritable bowel syndrome. So far, only a few preclinical animal studies have investigated the effect of protease inhibitors specifically on visceral sensitivity while their effect on inflammation is described in more detail. In our accompanying review we describe their effect on gastrointestinal permeability. On account of their promising results in the field of visceral hypersensitivity, further research is warranted. The aim of this review is to give an overview on the concept of visceral hypersensitivity as well as on the physiological and pathophysiological functions of proteases herein.
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Lee EH, Yang HR, Lee HS. Analysis of Gastric and Duodenal Eosinophils in Children with Abdominal Pain Related Functional Gastrointestinal Disorders According to Rome III Criteria. J Neurogastroenterol Motil 2016; 22:459-69. [PMID: 27053514 PMCID: PMC4930301 DOI: 10.5056/jnm15174] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Revised: 01/27/2016] [Accepted: 03/05/2016] [Indexed: 12/14/2022] Open
Abstract
Background/Aims Abdominal pain-related functional gastrointestinal disorder (AP-FGID) is common in children and adults. However, the mechanism of AP-FGID is not clearly known. Recently, micro-inflammation, especially eosinophilia in the gastrointestinal tract, was suggested in the pathophysiology of AP-FGID in adults. The aim of this study was to evaluate the association of gastric and duodenal eosinophilia with pediatric AP-FGID. Methods In total, 105 pediatric patients with AP-FGID were recruited and classified into 4 subgroups based on the Rome III criteria. Eosinophil counts in the gastric and duodenal tissues of children with AP-FGID were compared to those from normal pathology references or those of children with Helicobacter pylori infection. Tissue eosinophil counts were also compared among the 4 subtypes of AP-FGID. Results Eosinophil counts in the gastric antrum and body were significantly higher in children with AP-FGID than normal reference values. Duodenal eosinophil counts were higher in children with AP-FGID, but not significantly when compared with normal reference values. There were no significant differences in eosinophil counts of the stomach or duodenum among the 4 subtypes of AP-FGID. Eosinophils counts in the gastric antrum and body were significantly higher in children with H. pylori infection than in those with AP-FGID. Duodenal eosinophilia was prominent in cases of H. pylori infection, but not statistically significant when compared with AP-FGID. Conclusions Our study revealed that gastric eosinophilia is associated with AP-FGID in children, regardless of the subtype of functional abdominal pain. This suggests some contribution of gastrointestinal eosinophils in the development of pediatric AP-FGID.
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Affiliation(s)
- Eun Hye Lee
- Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
| | - Hye Ran Yang
- Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea.,Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Hye Seung Lee
- Department of Pathology, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
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Zhang L, Song J, Hou X. Mast Cells and Irritable Bowel Syndrome: From the Bench to the Bedside. J Neurogastroenterol Motil 2016; 22:181-92. [PMID: 26755686 PMCID: PMC4819856 DOI: 10.5056/jnm15137] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 12/07/2015] [Accepted: 12/26/2015] [Indexed: 12/11/2022] Open
Abstract
Irritable bowel syndrome (IBS) is traditionally defined as a functional disorder since it lacks demonstrable pathological abnormalities. However, in recent years, low grade inflammatory infiltration, often rich in mast cells, in both the small and large bowel, has been observed in some patients with IBS. The close association of mast cells with major intestinal functions, such as epithelial secretion and permeability, neuroimmune interactions, visceral sensation, and peristalsis, makes researchers and gastroenterologists to focus attention on the key roles of mast cells in the pathogenesis of IBS. Numerous studies have been carried out to identify the mechanisms in the development, infiltration, activation, and degranulation of intestinal mast cells, as well as the actions of mast cells in the processes of mucosal barrier disruption, mucosal immune dysregulation, visceral hypersensitivity, dysmotility, and local and central stress in IBS. Moreover, therapies targeting mast cells, such as mast cell stabilizers (cromoglycate and ketotifen) and antagonists of histamine and serotonin receptors, have been tried in IBS patients, and have partially exhibited considerable efficacy. This review focuses on recent advances in the role of mast cells in IBS, with particular emphasis on bridging experimental data with clinical therapeutics for IBS patients.
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Affiliation(s)
- Lei Zhang
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Song
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaohua Hou
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Abstract
Visceral pain is a highly complex entity whose experience is variable in health and disease. It can occur in patients with organic disease and also in those without any readily identifiable structural or biochemical abnormality such as in the functional gastrointestinal disorders (FGID). Despite considerable progress in our understanding of the culpable underlying mechanisms significant knowledge gaps remain, representing a significant unmet need in gastroenterology. A key, but not universal, pathological feature is that patients with FGID often display heightened sensitivity to experimental gut stimulation, termed visceral hypersensitivity. A plethora of factors have been proposed to account for this epiphenomenon including peripheral sensitization, central sensitization, aberrant central processing, genetic, psychological and abnormalities within the stress responsive systems. Further research is needed, bringing together complementary research themes from a diverse array of academic disciplines ranging from gastroenterology to nociceptive physiology to functional neuro-imaging, to address this unmet need.
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Affiliation(s)
- Adam D Farmer
- Department of Gastroenterology, Shrewsbury & Telford Hospitals NHS Trust, Princess Royal Hospital, Apley Castle, Telford, Shropshire, UK ; 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, UK
| | - Qasim Aziz
- 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, UK
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Distrutti E, Cipriani S, Mencarelli A, Renga B, Fiorucci S. Probiotics VSL#3 protect against development of visceral pain in murine model of irritable bowel syndrome. PLoS One 2013; 8:e63893. [PMID: 23691109 PMCID: PMC3655059 DOI: 10.1371/journal.pone.0063893] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Accepted: 04/07/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND AIMS Irritable bowel syndrome (IBS) is linked to post-inflammatory and stress-correlated factors that cause changes in the perception of visceral events. Probiotic bacteria may be effective in treating IBS symptoms. Here, we have investigated whether early life administration of VSL#3, a mixture of 8 probiotic bacteria strains, protects against development of visceral hypersensitivity driven by neonatal maternal separation (NMS), a rat model of IBS. METHODS Male NMS pups were treated orally with placebo or VSL#3 from days 3 to 60, while normal, not separated rats were used as controls. After 60 days from birth, perception of painful sensation induced by colorectal distension (CRD) was measured by assessing the abdominal withdrawal reflex (score 0-4). The colonic gene expression was assessed by using the Agilent Whole Rat Genome Oligo Microarrays platform and confirmed by real time PCR. RESULTS NMS rats exhibited both hyperalgesia and allodynia when compared to control rats. VSL#3 had a potent analgesic effect on CRD-induced pain without changing the colorectal compliance. The microarray analysis demonstrated that NMS induces a robust change in the expression of subsets of genes (CCL2, NOS3, THP1, NTRK1, CCR2, BDRKRB1, IL-10, TNFRSF1B, TRPV4, CNR1 and OPRL1) involved in pain transmission and inflammation. TPH1, tryptophan hydroxylase 1, a validated target gene in IBS treatment, was markedly upregulated by NMS and this effect was reversed by VSL#3 intervention. CONCLUSIONS Early life administration of VSL#3 reduces visceral pain perception in a model of IBS and resets colonic expression of subsets of genes mediating pain and inflammation. TRANSCRIPT PROFILING Accession number of repository for expression microarray data is GSE38942 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE38942).
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Affiliation(s)
- Eleonora Distrutti
- S.C. di Gastroenterologia ed Epatologia, Azienda Ospedaliera di Perugia, Perugia, Italy.
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Matricon J, Meleine M, Gelot A, Piche T, Dapoigny M, Muller E, Ardid D. Review article: Associations between immune activation, intestinal permeability and the irritable bowel syndrome. Aliment Pharmacol Ther 2012; 36:1009-31. [PMID: 23066886 DOI: 10.1111/apt.12080] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 09/18/2012] [Accepted: 09/19/2012] [Indexed: 02/06/2023]
Abstract
BACKGROUND Irritable bowel syndrome (IBS), one of the most common gastrointestinal disorders, markedly impairing patients' quality of life. Drug development for IBS treatment has been hampered by the lack of understanding of IBS aetiology. In recent years, numerous data have emerged that suggest the involvement of immune activation in IBS, at least in a subset of patients. AIM To determine whether immune activation and intestinal permeabilisation are more frequently observed in IBS patients compared with healthy controls. METHODS The scientific bibliography was searched using the following keywords: irritable bowel syndrome, inflammation, immune activation, permeabilisation, intestine, assay, histology and human. The retrieved studies, including blood, faecal and histological studies, were analysed to provide a comprehensive and structured overview of the available data including the type of assay, type of inflammatory marker investigated or intestinal segment studied. RESULTS Immune activation was more frequently observed in IBS patients than in healthy controls. An increase in the number of mast cells and lymphocytes, an alteration in cytokine levels and intestinal permeabilisation were reported in IBS patients. No consistent changes in the numbers of B cells or enterochromaffin cells or in mucosal serotonin production were demonstrated. CONCLUSIONS The changes observed were modest and often heterogeneous among the studied population. Only appropriate interventions improving irritable bowel syndrome symptoms could highlight and confirm the role of immune activation in this pathophysiology.
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Affiliation(s)
- J Matricon
- Clermont Université, Université d'Auvergne, NEURO-DOL, Clermont-Ferrand, France; Inserm, Clermont-Ferrand, France.
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Chen CW, Chen QB, Ouyang Q, Sun JH, Liu FT, Song DW, Yuan HB. Transient early neurotrophin release and delayed inflammatory cytokine release by microglia in response to PAR-2 stimulation. J Neuroinflammation 2012; 9:142. [PMID: 22731117 PMCID: PMC3419072 DOI: 10.1186/1742-2094-9-142] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 05/23/2012] [Indexed: 12/17/2022] Open
Abstract
Activated microglia exerts both beneficial and deleterious effects on neurons, but the signaling mechanism controlling these distinct responses remain unclear. We demonstrated that treatment of microglial cultures with the PAR-2 agonist, 2-Furoyl-LIGRLO-NH2, evoked early transient release of BDNF, while sustained PAR-2 stimulation evoked the delayed release of inflammatory cytokines (IL-1 β and TNF-α) and nitric oxide. Culture medium harvested during the early phase (at 1 h) of microglial activation induced by 2-Furoyl-LIGRLO-NH2 (microglial conditioned medium, MCM) had no deleterious effects on cultured neurons, while MCM harvested during the late phase (at 72 h) promoted DNA fragmentation and apoptosis as indicated by TUNEL and annexin/PI staining. Blockade of PAR-1 during the early phase of PAR-2 stimulation enhanced BDNF release (by 11%, small but significant) while a PAR-1 agonist added during the late phase (24 h after 2-Furoyl-LIGRLO-NH2 addition) suppressed the release of cytokines and NO. The neuroprotective and neurotoxic effects of activated microglial exhibit distinct temporal profiles that are regulated by PAR-1 and PAR-2 stimulation. It may be possible to facilitate neuronal recovery and repair by appropriately timed stimulation and inhibition of microglial PAR-1 and PAR-2 receptors.
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Affiliation(s)
- Chen-Wen Chen
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China.
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Anand P, Singh B, Jaggi AS, Singh N. Mast cells: an expanding pathophysiological role from allergy to other disorders. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:657-70. [PMID: 22562473 DOI: 10.1007/s00210-012-0757-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 04/17/2012] [Indexed: 12/16/2022]
Abstract
The mast cells are multi-effector cells with wide distribution in the different body parts and traditionally their role has been well-defined in the development of IgE-mediated hypersensitivity reactions including bronchial asthma. Due to the availability of genetically modified mast cell-deficient mice, the broadened pathophysiological role of mast cells in diverse diseases has been revealed. Mast cells exert different physiological and pathophysiological roles by secreting their granular contents, including vasoactive amines, cytokines and chemokines, and various proteases, including tryptase and chymase. Furthermore, mast cells also synthesize plasma membrane-derived lipid mediators, including prostaglandins and leukotrienes, to produce diverse biological actions. The present review discusses the pathophysiological role of mast cells in different diseases, including atherosclerosis, pulmonary hypertension, ischemia-reperfusion injury, male infertility, autoimmune disorders such as rheumatoid arthritis and multiple sclerosis, bladder pain syndrome (interstitial cystitis), anxiety, Alzheimer's disease, nociception, obesity and diabetes mellitus.
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Affiliation(s)
- Preet Anand
- Department of Chemistry, Punjabi University, Patiala 147002, India
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Suckow SK, Anderson EM, Caudle RM. Lesioning of TRPV1 expressing primary afferent neurons prevents PAR-2 induced motility, but not mechanical hypersensitivity in the rat colon. Neurogastroenterol Motil 2012; 24:e125-35. [PMID: 22168801 PMCID: PMC3276722 DOI: 10.1111/j.1365-2982.2011.01848.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND Proteinase activated receptor 2 (PAR-2) is expressed by many neurons in the colon, including primary afferent neurons that co-express transient receptor potential vanilloid 1 (TRPV1). Activation of PAR-2 receptors was previously found to enhance colonic motility, increase secretion and produce hypersensitivity to mechanical stimuli. This study examined the functional role of TRPV1/PAR-2 expressing neurons that innervate the colon by lesioning TRPV1 bearing neurons with the highly selective and potent TRPV1 agonist resiniferatoxin. METHODS Colonic motility in response to PAR-2 activation was evaluated in vitro using isolated segments of descending colon and in vivo using manometry. Colonic mechanical nociceptive thresholds were measured using colorectal distension. Transient receptor potential vanilloid 1 expressing neurons were selectively lesioned with resiniferatoxin. KEY RESULTS In vitro, the PAR-2 agonists, trypsin and SLIGRL did not alter contractions of colon segments when applied alone, however, the agents enhanced acetylcholine stimulated contraction. In vivo, PAR-2 agonists administered intraluminally induced contractions of the colon and produced hypersensitivity to colorectal distention. The PAR-2 agonist enhancement of colonic contraction was eliminated when TRPV1 expressing neurons were lesioned with resiniferatoxin, but the PAR-2 agonist induced hypersensitivity remained in the lesioned animals. CONCLUSIONS & INFERENCES Our findings indicate that TRPV1/PAR-2 expressing primary afferent neurons mediate an extrinsic motor reflex pathway in the colon. These data, coupled with our previous studies, also indicate that the recently described colospinal afferent neurons are nociceptive, suggesting that these neurons may be useful targets for the pharmacological control of pain in diseases such as irritable bowel syndrome.
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Affiliation(s)
- Shelby K. Suckow
- Department of Neuroscience, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, FL 32610, USA
| | - Ethan M. Anderson
- Department of Neuroscience, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, FL 32610, USA
| | - Robert M. Caudle
- Department of Oral and Maxillofacial Surgery, University of Florida College of Dentistry, Gainesville, FL 32610, USA,Department of Neuroscience, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, FL 32610, USA
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Han W, Wang Z, Lu X, Guo C. Protease activated receptor 4 status of mast cells in post infectious irritable bowel syndrome. Neurogastroenterol Motil 2012; 24:113-9, e82. [PMID: 22151913 DOI: 10.1111/j.1365-2982.2011.01841.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Growing evidence suggests that protease activated receptors (PARs) are mediators of persistent neuropathic pain, but their possible function as mediators in patients with post infectious irritable bowel syndrome (PI-IBS) remains to be further explored. This article aims to investigate the expression of PAR(2) and PAR(4) in the colonic mucosa of patients with PI-IBS, focusing on correlation with mast cell activation status. METHODS A total of 17 normal controls and 23 patients with PI-IBS volunteered the study. The expression and localization of PAR(2) and PAR(4) were investigated by RT-PCR and immunohistochemistry, and the expression of PAR(2) and PAR(4) in the mast cells was examined using double-immunofluorescence staining. KEY RESULTS The immunohistochemical study revealed that epithelial and submucosal cells showed immunoreactivity for both PAR(2) and PAR(4). Protease activated receptor 4 mRNA expression and immunoreactivity were down-regulated in PI-IBS compared with the control group. Specifically, a reduced immunoreactivity for PAR(4) was observed in mast cells of PI-IBS compared with normal controls, whereas there are no significant differences shown in PAR(2) between the PI-IBS and the control group. It is also found that the PAR(4) immunoreactivity decreases, while the activity of mast cells increases in PI-IBS rather than normal controls. CONCLUSIONS & INFERENCES This study outlines the down-regulation of PAR(4) in the mast cells of PI-IBS. It could be of considerable interests in understanding the mechanisms involved in the persistent colonic hypersensitivity and their potential role as therapeutic targets for PI-IBS.
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Affiliation(s)
- W Han
- Department of Gastroenterology, Qilu Hospital of Shandong University, Jinan, Shandong Province, China
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The expression of protease-activated receptor 2 and 4 in the colon of irritable bowel syndrome patients. Dig Dis Sci 2012; 57:58-64. [PMID: 21800160 DOI: 10.1007/s10620-011-1827-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 07/09/2011] [Indexed: 12/12/2022]
Abstract
BACKGROUND Irritable bowel syndrome (IBS) pathophysiology has not been fully understood. Abnormalities of serine proteases have been identified in IBS patients. In addition, protease-activated receptors (PAR) activation interferes with several components of the pathogenesis of IBS, so, evaluating the PAR expression in IBS patients may contribute to understanding the pathogenesis of the disease. AIMS This study aimed to investigate whether the expression of PAR4 and PAR2 in the colon was changed in IBS patients and was associated with IBS. METHODS Colon mucosal biopsies of 34 IBS patients (16 constipation- and 18 diarrhea-predominant) and 18 control subjects were collected. Gene transcripts of PAR2, PAR4, tryptase, and trypsin were quantified using real-time polymerase chain reaction (PCR) and the expression of PAR2 and PAR4 receptors was also measured by immunohistology and image analysis. RESULTS In IBS patients, the mRNA expression of tryptase and trypsin normalized against β-actin gene was higher compared to control subjects (P < 0.001). No difference was observed in the PAR2 mRNA level or protein level between control subjects on the one hand and IBS patients or subgroups on the other. In IBS or IBS subgroups patients, the expression of PAR4 in the mRNA level or protein level was lower than the control subjects. CONCLUSIONS This study, for the first time, indicated the PAR4 expression in IBS patients. Decreased PAR4 expression may help us to understand the pathogenesis of IBS.
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Mueller K, Michel K, Krueger D, Demir IE, Ceyhan GO, Zeller F, Kreis ME, Schemann M. Activity of protease-activated receptors in the human submucous plexus. Gastroenterology 2011; 141:2088-2097.e1. [PMID: 21875497 DOI: 10.1053/j.gastro.2011.08.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 07/25/2011] [Accepted: 08/19/2011] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Protease-activated receptors (PARs) are expressed in the enteric nervous system. Excessive release of proteases has been reported in functional and inflammatory bowel diseases. Studies in several animal models indicate the involvement of neural PARs. We studied the actions of different PAR-activating peptides (AP) in the human submucous plexus and performed comparative studies in guinea pig submucous neurons. METHODS We used voltage- and calcium-sensitive dye recordings to study the effects of PAR1-AP, PAR2-AP, PAR4-AP, the PAR1 activator thrombin, and the PAR2 activator tryptase on neurons and glia in human and guinea pig submucous plexus. Human preparations were derived from surgical resections. Levels of mucosal secretion evoked by PAR-APs were measured in Ussing chambers. RESULTS PAR1-AP and thrombin evoked a prominent spike discharge and intracellular Ca(2+) concentration ([Ca](i)) transients in most human submucous neurons and glia. PAR2-AP, tryptase, and PAR4-AP caused significantly weaker responses in a minor population. In contrast, PAR2-AP evoked much stronger responses in enteric neurons and glia of guinea pigs than did PAR1-AP or PAR4-AP. PAR1-AP, but not PAR2-AP or PAR4-AP, evoked a nerve-mediated secretion in human epithelium. The PAR1 antagonist SCH79797 inhibited the PAR1-AP, and thrombin evoked responses on neurons, glia, and epithelial secretion. In the submucous layer of human intestine, but not guinea pig intestine, PAR2-AP evoked [Ca](i) signals in CD68(+) macrophages. CONCLUSIONS In the human submucous plexus, PAR1, rather than PAR2 or PAR4, activates nerves and glia. These findings indicate that PAR1 should be the focus of future studies on neural PAR-mediated actions in the human intestine; PAR1 might be developed as a therapeutic target for gastrointestinal disorders associated with increased levels of proteases.
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Affiliation(s)
- Kerstin Mueller
- Human Biology, Technische Universität München, Freising, Germany
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Ford AC, Talley NJ. Mucosal inflammation as a potential etiological factor in irritable bowel syndrome: a systematic review. J Gastroenterol 2011; 46:421-31. [PMID: 21331765 DOI: 10.1007/s00535-011-0379-9] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 01/19/2011] [Indexed: 02/04/2023]
Abstract
BACKGROUND The causes of irritable bowel syndrome (IBS) remain obscure. Some investigators have proposed chronic low-grade mucosal inflammation as a potential etiological factor. We performed a systematic review to examine this issue in detail. METHODS MEDLINE, EMBASE, and EMBASE classic were searched up to December 2010 to identify studies of case-control design applying tests for low-grade inflammation to either full-thickness intestinal or endoscopic mucosal biopsies from patients with IBS. Controls were required to be healthy individuals, or asymptomatic patients undergoing investigation for reasons other than the reporting of upper or lower gastrointestinal symptoms. Individual study results were summarized descriptively. RESULTS The literature search identified 1388 citations, of which 16 studies were eligible for inclusion. Individual study results were diverse, partly as a consequence of the different surrogate markers for inflammatory mechanisms studied. Mast cells, T lymphocytes, B lymphocytes, and mucosal cytokine production all appeared altered among cases with IBS in individual studies, while no study demonstrated a significant difference in numbers of plasma cells, neutrophils, or eosinophils. Some studies suggested a relationship between mast cell abnormalities and symptom severity and frequency, as well as co-existent fatigue and depression. Studies were limited by the lack of comparability of controls, and the fact that most were conducted in highly selected groups of patients with IBS. CONCLUSIONS Low-grade mucosal inflammation, particularly mast cell activation, may be a contributory factor in the pathogenesis of IBS. Mast cell stabilizers warrant further assessment as a potential therapy in the condition.
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Affiliation(s)
- Alexander C Ford
- Leeds Gastroenterology Institute, D Floor, Clarendon Wing, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, UK.
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Malinen E, Krogius-Kurikka L, Lyra A, Nikkilä J, Jääskeläinen A, Rinttilä T, Vilpponen-Salmela T, Wright AJV, Palva A. Association of symptoms with gastrointestinal microbiota in irritable bowel syndrome. World J Gastroenterol 2010; 16:4532-40. [PMID: 20857523 PMCID: PMC2945484 DOI: 10.3748/wjg.v16.i36.4532] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the correlations between self-reported symptoms of irritable bowel syndrome (IBS) and the gastrointestinal (GI) microbiota composition.
METHODS: Fecal samples were collected from a total of 44 subjects diagnosed with IBS. Their symptoms were monitored with a validated inflammatory bowel disease questionnaire adjusted for IBS patients. Thirteen quantitative real-time polymerase chain reaction assays were applied to evaluate the GI microbiota composition. Eubacteria and GI bacterial genera (Bifidobacterium, Lactobacillus and Veillonella), groups (Clostridium coccoides/Eubacterium rectale, Desulfovibrio desulfuricans) and distinct bacterial phylotypes [closest 16S rDNA sequence resemblance to species Bifidobacterium catenulatum, Clostridium cocleatum, Collinsella aerofaciens (C. aerofaciens), Coprococcus eutactus (C. eutactus), Ruminococcus torques and Streptococcus bovis] with a suspected association with IBS were quantified. Correlations between quantities or presence/absence data of selected bacterial groups or phylotypes and various IBS-related symptoms were investigated.
RESULTS: Associations were observed between subjects’ self-reported symptoms and the presence or quantities of certain GI bacteria. A Ruminococcus torques (R. torques)-like (94% similarity in 16S rRNA gene sequence) phylotype was associated with severity of bowel symptoms. Furthermore, among IBS subjects with R. torques 94% detected, the amounts of C. cocleatum 88%, C. aerofaciens-like and C. eutactus 97% phylotypes were significantly reduced. Interesting observations were also made concerning the effect of a subject’s weight on GI microbiota with regard to C. aerofaciens-like phylotype, Bifidobacterium spp. and Lactobacillus spp.
CONCLUSION: Bacteria seemingly affecting the symptom scores are unlikely to be the underlying cause or cure of IBS, but they may serve as biomarkers of the condition.
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