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Trypsin Depolarizes Pacemaker Potentials in Murine Small Intestinal Interstitial Cells of Cajal. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12094755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Interstitial cells of Cajal (ICCs) generate pacemaker potentials in the gastrointestinal (GI) tract. In this study, the effects of trypsin on pacemaker potentials in murine small intestinal ICCs were examined. We used whole-cell patch-clamp analysis. The results of whole-cell patch-clamp analysis revealed that trypsin dose-dependently depolarized pacemaker potentials and decreased their amplitude. Treatments with the antagonists of neurokinin1 (NK1) and NK2 receptors (SR-140333 and SR-48968, respectively) slightly inhibited the trypsin-induced responses. However, treatment with the combination of SR-140333 and SR-48968 completely inhibited trypsin-induced responses. Trypsin slightly depolarized pacemaker potentials and increased their amplitude after the intracellular application of GDP-β-S. Additionally, incubation in external Ca2+-free solution inhibited trypsin-induced responses. In the presence of U-73122, staurosporine, Go6976, or xestospongin C, trypsin did not depolarize the pacemaker’s potentials. However, trypsin depolarized the pacemaker potentials in the presence of rottlerin. Finally, HC067047, a TRPV4 inhibitor, did not affect the trypsin-induced responses. These results suggest that trypsin depolarized pacemaker potentials through NK1 and NK2 receptors in the murine small intestinal ICCs, with this effect being dependent on the G protein, phospholipase C, protein kinase C, inositol triphosphate pathways, and extracellular Ca2+ but being independent of the TRPV4 pathway. Hence, trypsin-mediated GI motility regulation must be considered for prokinetic drug developments.
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Oliveira KA, Torquato RJS, Lustosa DCGG, Ribeiro T, Nascimento BWL, de Oliveira LCG, Juliano MA, Paschoalin T, Lemos VS, Araujo RN, Pereira MH, Tanaka AS. Proteolytic activity of Triatoma infestans saliva associated with PAR-2 activation and vasodilation. J Venom Anim Toxins Incl Trop Dis 2021; 27:e20200098. [PMID: 33747067 PMCID: PMC7939238 DOI: 10.1590/1678-9199-jvatitd-2020-0098] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background Triatoma infestans (Hemiptera: Reduviidae) is a
hematophagous insect and the main vector of Trypanosoma
cruzi (Kinetoplastida: Trypanosomatidae). In the present study,
the authors investigated whether a serine protease activity from the saliva
of T. infestans has a role in vasomotor modulation, and in
the insect-blood feeding by cleaving and activating protease-activated
receptors (PARs). Methods T. infestans saliva was chromatographed as previously
reported for purification of triapsin, a serine protease. The cleavage
activity of triapsin on PAR peptides was investigated based on FRET
technology. Mass spectrometry was used to analyze the sites of PAR-2 peptide
cleaved by triapsin. NO measurements were performed using the DAN assay
(2,3-diaminonapthalene). The vasorelaxant activity of triapsin was measured
in vessels with or without functional endothelium pre-contracted with
phenylephrine (3 µM). Intravital microscopy was used to assess the effect of
triapsin on mouse skin microcirculation. Results Triapsin was able to induce hydrolysis of PAR peptides and showed a higher
preference for cleavage of the PAR-2 peptide. Analysis by mass spectrometry
confirmed a single cleavage site, which corresponds to the activation site
of the PAR-2 receptor. Triapsin induced dose-dependent NO release in
cultured human umbilical vein endothelial cells (HUVECs), reaching a maximum
effect at 17.58 nM. Triapsin purified by gel-filtration chromatography
(10-16 to 10-9 M) was applied cumulatively to
mouse mesenteric artery rings and showed a potent endothelium-dependent
vasodilator effect (EC30 = 10-12 M). Nitric oxide
seems to be partially responsible for this vasodilator effect because L-NAME
(L-NG-nitroarginine methyl ester 300 µM), a nitric oxide synthetase
inhibitor, did not abrogate the vasodilation activated by triapsin.
Anti-PAR-2 antibody completely inhibited vasodilation observed in the
presence of triapsin activity. Triapsin activity also induced an increase in
the mouse ear venular diameter. Conclusion Data from this study suggest a plausible association between triapsin
activity mediated PAR-2 activation and vasodilation caused by T.
infestans saliva.
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Affiliation(s)
- Karla A Oliveira
- Department of Biochemistry and Pharmacology, Federal University of Piauí, Teresina, PI, Brazil
| | - Ricardo J S Torquato
- Department of Biochemistry, Federal University of São Paulo (Unifesp), São Paulo, SP, Brazil
| | - Daniela C G Garcia Lustosa
- Department of Pharmacology, Institute of Biomedical Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Tales Ribeiro
- Department of Parasitology, Institute of Biomedical Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Bruno W L Nascimento
- Department of Parasitology, Institute of Biomedical Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Lilian C G de Oliveira
- Department of Biophysics, National Institute of Pharmacology and Molecular Biology (INFAR), Federal University of São Paulo (Unifesp), São Paulo, SP, Brazil
| | - Maria A Juliano
- Department of Biophysics, National Institute of Pharmacology and Molecular Biology (INFAR), Federal University of São Paulo (Unifesp), São Paulo, SP, Brazil
| | - Thaysa Paschoalin
- Department of Biophysics, National Institute of Pharmacology and Molecular Biology (INFAR), Federal University of São Paulo (Unifesp), São Paulo, SP, Brazil
| | - Virginia S Lemos
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Ricardo N Araujo
- Department of Parasitology, Institute of Biomedical Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.,National Institute of Science and Technology in Molecular Entomology (INCT-EM), Rio de Janeiro, RJ, Brazil
| | - Marcos H Pereira
- Department of Parasitology, Institute of Biomedical Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.,National Institute of Science and Technology in Molecular Entomology (INCT-EM), Rio de Janeiro, RJ, Brazil
| | - Aparecida S Tanaka
- Department of Biochemistry, Federal University of São Paulo (Unifesp), São Paulo, SP, Brazil.,National Institute of Science and Technology in Molecular Entomology (INCT-EM), Rio de Janeiro, RJ, Brazil
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Carco C, Young W, Gearry RB, Talley NJ, McNabb WC, Roy NC. Increasing Evidence That Irritable Bowel Syndrome and Functional Gastrointestinal Disorders Have a Microbial Pathogenesis. Front Cell Infect Microbiol 2020; 10:468. [PMID: 33014892 PMCID: PMC7509092 DOI: 10.3389/fcimb.2020.00468] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022] Open
Abstract
The human gastrointestinal tract harbors most of the microbial cells inhabiting the body, collectively known as the microbiota. These microbes have several implications for the maintenance of structural integrity of the gastrointestinal mucosal barrier, immunomodulation, metabolism of nutrients, and protection against pathogens. Dysfunctions in these mechanisms are linked to a range of conditions in the gastrointestinal tract, including functional gastrointestinal disorders, ranging from irritable bowel syndrome, to functional constipation and functional diarrhea. Irritable bowel syndrome is characterized by chronic abdominal pain with changes in bowel habit in the absence of morphological changes. Despite the high prevalence of irritable bowel syndrome in the global population, the mechanisms responsible for this condition are poorly understood. Although alterations in the gastrointestinal microbiota, low-grade inflammation and immune activation have been implicated in the pathophysiology of functional gastrointestinal disorders, there is inconsistency between studies and a lack of consensus on what the exact role of the microbiota is, and how changes to it relate to these conditions. The complex interplay between host factors, such as microbial dysbiosis, immune activation, impaired epithelial barrier function and motility, and environmental factors, including diet, will be considered in this narrative review of the pathophysiology of functional gastrointestinal disorders.
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Affiliation(s)
- Caterina Carco
- School of Food and Advanced Technology, Massey University, Palmerston North, New Zealand.,Riddet Institute, Massey University, Palmerston North, New Zealand.,Food Nutrition and Health Team, AgResearch Grasslands, Palmerston North, New Zealand.,The High-Value Nutrition National Science Challenge, Auckland, New Zealand
| | - Wayne Young
- Riddet Institute, Massey University, Palmerston North, New Zealand.,Food Nutrition and Health Team, AgResearch Grasslands, Palmerston North, New Zealand.,The High-Value Nutrition National Science Challenge, Auckland, New Zealand
| | - Richard B Gearry
- The High-Value Nutrition National Science Challenge, Auckland, New Zealand.,Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Nicholas J Talley
- Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
| | - Warren C McNabb
- Riddet Institute, Massey University, Palmerston North, New Zealand.,The High-Value Nutrition National Science Challenge, Auckland, New Zealand
| | - Nicole C Roy
- Riddet Institute, Massey University, Palmerston North, New Zealand.,The High-Value Nutrition National Science Challenge, Auckland, New Zealand.,Liggins Institute, University of Auckland, Auckland, New Zealand.,Department of Human Nutrition, University of Otago, Dunedin, New Zealand
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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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Ha HS, Lee SE, Lee HS, Kim GH, Yoon CJ, Han JS, Lee JY, Sohn UD. The signaling of protease-activated receptor-2 activating peptide-induced contraction in cat esophageal smooth muscle cells. Arch Pharm Res 2017; 40:1443-1454. [PMID: 29098568 DOI: 10.1007/s12272-017-0975-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/19/2017] [Indexed: 11/26/2022]
Abstract
Protease-activated receptors (PARs) are a family of G protein-coupled receptors with a unique activation mechanism involving proteolytic cleavage of the extracellular N-terminal domain of the receptor. PAR2 has a contractile effect on esophageal smooth muscle. We investigate the signaling pathways of the PAR2-activating peptide (PAR2-AP) induced contraction in cat esophageal smooth muscle cells. The length of freshly isolated smooth muscle cells and permeabilized cells from feline esophagus were measured by scanning micrometry, and by confirming molecular basis via western blot analysis. The responses to PAR2-AP were initial and sustained contractions, depending on time. The maximum contraction of the initial phase occurred at 60 s. The PAR2-AP-induced contraction was mediated by Gαi1, Gαi3, and Gαq protein activation, leading to phospholipase-c (PLC) and myosin light chain kinase (MLCK) activation. 20 kDa myosin light chain (MLC20) was phosphorylated by PAR2-AP. Rho kinase-2 (ROCK-2), an activator of 17 kDa C-kinase potentiated Protein phosphatase-1 Inhibitor (CPI-17), was increased by PAR2 receptor activation. In conclusion, PAR2-AP produced an initial contraction mediated by Gαi1, Gαi3, and Gαq protein activation, resulting in PLC and MLCK activation. The sustained contraction by PAR2-AP was mediated by the Rho/Rho kinase-dependent pathway.
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Affiliation(s)
- Hyun Su Ha
- College of Pharmacy, Chung-Ang University, Seoul, 156 -756, Republic of Korea
| | - Se Eun Lee
- College of Pharmacy, Chung-Ang University, Seoul, 156 -756, Republic of Korea
| | - Hyun Seok Lee
- College of Pharmacy, Chung-Ang University, Seoul, 156 -756, Republic of Korea
| | - Gil Hyung Kim
- College of Pharmacy, Chung-Ang University, Seoul, 156 -756, Republic of Korea
| | - Chan Jong Yoon
- College of Pharmacy, Chung-Ang University, Seoul, 156 -756, Republic of Korea
| | - Jong Soo Han
- College of Pharmacy, Chung-Ang University, Seoul, 156 -756, Republic of Korea
| | - Ji-Yun Lee
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea.
| | - Uy Dong Sohn
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea.
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Tanaka Y, Ihara E, Hirano K, Takahashi S, Hirano M, Nakamura K, Akiho H, Oda Y, Takayanagi R. Trypsin-induced biphasic regulation of tone in the porcine lower esophageal sphincter. Eur J Pharmacol 2015; 752:97-105. [DOI: 10.1016/j.ejphar.2015.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 02/03/2015] [Accepted: 02/10/2015] [Indexed: 01/10/2023]
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7
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Sung TS, Kim HU, Kim JH, Lu H, Sanders KM, Koh SD. Protease-activated receptors modulate excitability of murine colonic smooth muscles by differential effects on interstitial cells. J Physiol 2015; 593:1169-81. [PMID: 25641660 PMCID: PMC4358678 DOI: 10.1113/jphysiol.2014.285148] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/22/2014] [Indexed: 12/12/2022] Open
Abstract
Protease-activated receptors (PARs) are G protein-coupled receptors activated by proteolytic cleavage at their amino termini by serine proteases. PAR activation contributes to the inflammatory response in the gastrointestinal (GI) tract and alters GI motility, but little is known about the specific cells within the tunica muscularis that express PARs and the mechanisms leading to contractile responses. Using real time PCR, we found PARs to be expressed in smooth muscle cells (SMCs), interstitial cells of Cajal (ICC) and platelet-derived growth factor receptor α positive (PDGFRα(+)) cells. The latter cell-type showed dominant expression of F2r (encodes PAR1) and F2rl1 (encodes PAR2). Contractile and intracellular electrical activities were measured to characterize the integrated responses to PAR activation in whole muscles. Cells were isolated and ICC and PDGFRα(+) cells were identified by constitutive expression of fluorescent reporters. Thrombin (PAR1 agonist) and trypsin (PAR2 agonist) caused biphasic responses in colonic muscles: transient hyperpolarization and relaxation followed by repolarization and excitation. The inhibitory phase was blocked by apamin, revealing a distinct excitatory component. Patch clamp studies showed that the inhibitory response was mediated by activation of small conductance calcium-activated K(+) channels in PDGFRα(+) cells, and the excitatory response was mediated by activation of a Cl(-) conductance in ICC. SMCs contributed little to PAR responses in colonic muscles. In summary, PARs regulate the excitability of colonic muscles; different conductances are activated in each cell type of the SMC-ICC-PDGFRα(+) cell (SIP) syncytium. Motor responses to PAR agonists are integrated responses of the SIP syncytium.
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MESH Headings
- Action Potentials
- Animals
- Cells, Cultured
- Chloride Channels/antagonists & inhibitors
- Chloride Channels/metabolism
- Colon/cytology
- Colon/metabolism
- Interstitial Cells of Cajal/metabolism
- Interstitial Cells of Cajal/physiology
- Mice
- Mice, Inbred C57BL
- Muscle Contraction
- Muscle, Smooth/metabolism
- Muscle, Smooth/physiology
- Potassium Channels, Calcium-Activated/metabolism
- Potassium Channels, Inwardly Rectifying/metabolism
- Receptor, PAR-1/agonists
- Receptor, PAR-1/genetics
- Receptor, PAR-1/metabolism
- Receptor, PAR-2/agonists
- Receptor, PAR-2/genetics
- Receptor, PAR-2/metabolism
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Affiliation(s)
- Tae Sik Sung
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, RenoNV 89557, USA
| | - Heung Up Kim
- Department of Internal Medicine, School of Medicine, Jeju National UniversityJeju, Korea
| | - Jeong Hwan Kim
- Department of Internal Medicine, School of Medicine, Konkuk University Medical CentreSeoul, Korea
| | - Hongli Lu
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, RenoNV 89557, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, RenoNV 89557, USA
| | - Sang Don Koh
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, RenoNV 89557, 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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Ruan YC, Zhou W, Chan HC. Regulation of smooth muscle contraction by the epithelium: role of prostaglandins. Physiology (Bethesda) 2011; 26:156-70. [PMID: 21670162 DOI: 10.1152/physiol.00036.2010] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
As an analog to the endothelium situated next to the vascular smooth muscle, the epithelium is emerging as an important regulator of smooth muscle contraction in many vital organs/tissues by interacting with other cell types and releasing epithelium-derived factors, among which prostaglandins have been demonstrated to play a versatile role in governing smooth muscle contraction essential to the physiological and pathophysiological processes in a wide range of organ systems.
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Affiliation(s)
- Ye Chun Ruan
- School of Life Science, Sun Yat-sen University, China
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Rothmeier AS, Ruf W. Protease-activated receptor 2 signaling in inflammation. Semin Immunopathol 2011; 34:133-49. [PMID: 21971685 DOI: 10.1007/s00281-011-0289-1] [Citation(s) in RCA: 221] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 09/05/2011] [Indexed: 12/17/2022]
Abstract
Protease-activated receptors (PARs) are G protein-coupled receptors that are activated by proteolytical cleavage of the amino-terminus and thereby act as sensors for extracellular proteases. While coagulation proteases activate PARs to regulate hemostasis, thrombosis, and cardiovascular function, PAR2 is also activated in extravascular locations by a broad array of serine proteases, including trypsin, tissue kallikreins, coagulation factors VIIa and Xa, mast cell tryptase, and transmembrane serine proteases. Administration of PAR2-specific agonistic and antagonistic peptides, as well as studies in PAR2 knockout mice, identified critical functions of PAR2 in development, inflammation, immunity, and angiogenesis. Here, we review these roles of PAR2 with an emphasis on the role of coagulation and other extracellular protease pathways that cleave PAR2 in epithelial, immune, and neuronal cells to regulate physiological and pathophysiological processes.
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Affiliation(s)
- Andrea S Rothmeier
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
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Borrelli F, Capasso R, Severino B, Fiorino F, Aviello G, De Rosa G, Mazzella M, Romano B, Capasso F, Fasolino I, Izzo AA. Inhibitory effects of bromelain, a cysteine protease derived from pineapple stem (Ananas comosus), on intestinal motility in mice. Neurogastroenterol Motil 2011; 23:745-e331. [PMID: 21689210 DOI: 10.1111/j.1365-2982.2011.01735.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Bromelain (BR) is a cysteine protease with inhibitory effects on intestinal secretion and inflammation. However, its effects on intestinal motility are largely unexplored. Thus, we investigated the effect of this plant-derived compound on intestinal contractility and transit in mice. METHODS Contractility in vitro was evaluated by stimulating the mouse isolated ileum, in an organ bath, with acetylcholine, barium chloride, or electrical field stimulation. Motility in vivo was measured by evaluating the distribution of an orally administered fluorescent marker along the small intestine. Transit was also evaluated in pathophysiologic states induced by the pro-inflammatory compound croton oil or by the diabetogenic agent streptozotocin. KEY RESULTS Bromelain inhibited the contractions induced by different spasmogenic compounds in the mouse ileum with similar potency. The antispasmodic effect was reduced or counteracted by the proteolytic enzyme inhibitor, gabexate (15 × 10(-6) mol L(-1) ), protease-activated receptor-2 (PAR-2) antagonist, N(1) -3-methylbutyryl-N(4) -6-aminohexanoyl-piperazine (10(-4) mol L(-1) ), phospholipase C (PLC) inhibitor, neomycin (3 × 10(-3) mol L(-1) ), and phosphodiesterase 4 (PDE4) inhibitor, rolipram (10(-6) mol L(-1) ). In vivo, BR preferentially inhibited motility in pathophysiologic states in a PAR-2-antagonist-sensitive manner. CONCLUSIONS & INFERENCES Our data suggest that BR inhibits intestinal motility - preferentially in pathophysiologic conditions - with a mechanism possibly involving membrane PAR-2 and PLC and PDE4 as intracellular signals. Bromelain could be a lead compound for the development of new drugs, able to normalize the intestinal motility in inflammation and diabetes.
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Affiliation(s)
- F Borrelli
- Department of Experimental Pharmacology, University of Naples Federico II, Via D. Montesano 49, Naples, Italy.
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Long-term downregulation of protease-activated receptor-2 expression in distal colon in rats following bacillary dysentery. ACTA ACUST UNITED AC 2010; 163:49-56. [PMID: 20347884 DOI: 10.1016/j.regpep.2010.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Revised: 02/21/2010] [Accepted: 03/16/2010] [Indexed: 12/11/2022]
Abstract
The aim of this study was to determine changes of PAR-2 expression in distal colon and the sensitivity of colonic muscle to SLIGRL-NH2, the PAR-2-activating peptide (PAR-2-AP) following bacillary dysentery. Shigella flexneri was administrated intragastrically in healthy male rats to induce bacillary dysentery. The effect of SLIGRL-NH2 on the motility of colonic muscle strips were examined. The expression of PAR-2 was determined by immunohistochemistry and Western blotting. Intragastric administration of S.flexneri induced acute inflammation at the mucosa of the distal colon at 4-11 days, and the inflammation disappeared 18 days later. PAR-2-AP-induced TTX insensitive relaxation of the colonic muscle strips. This inhibitory effect on colonic circular muscle strips was reduced on days 11-35, but the carbachol-induced contraction did not change. PAR-2 was located at the colon smooth muscles cells and myenteric nerve plexus. The amount of PAR-2 expression in distal colon was down regulated on days 11-35. These data indicated that bacillary dysentery exerted a long-term downregulation on the expression of PAR-2 in distal colon. This might be the reason of the low sensitivity of the colon circular muscle strips to the PAR-2-AP-induced relaxation following intragastric administration of S.flexneri.
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13
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Severini C, La Corte G, Improta G, Broccardo M, Agostini S, Petrella C, Sibilia V, Pagani F, Guidobono F, Bulgarelli I, Ferri GL, Brancia C, Rinaldi AM, Levi A, Possenti R. In vitro and in vivo pharmacological role of TLQP-21, a VGF-derived peptide, in the regulation of rat gastric motor functions. Br J Pharmacol 2009; 157:984-93. [PMID: 19466987 DOI: 10.1111/j.1476-5381.2009.00192.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Vgf gene expression has been detected in various endocrine and neuronal cells in the gastrointestinal tract. In this study we investigated the pharmacological activity of different VGF-derived peptides. Among these, TLQP-21, corresponding to the 556-576 fragment of the protein was the unique active peptide, and its pharmacological profile was further studied. EXPERIMENTAL APPROACH The effects of TLQP-21 were examined in vitro by smooth muscle contraction in isolated preparations from the rat gastrointestinal tract and, in vivo, by assessing gastric emptying in rats. Rat stomach tissues were also processed for immunohistochemical and biochemical characterization. KEY RESULTS In rat longitudinal forestomach strips, TLQP-21 (100 nmol x L(-1)-10 micromol x L(-1)) concentration-dependently induced muscle contraction (in female rats, EC(50) = 0.47 micromol.L(-1), E(max): 85.7 +/- 7.9 and in male rats, 0.87 micromol x L(-1), E(max): 33.4 +/- 5.3; n = 8), by release of prostaglandin (PG)E(2) and PGF(2a) from the mucosal layer. This effect was significantly antagonized by indomethacin and selective inhibitors of either cyclooxygenase-1 (S560) or cyclooxygenase-2 (NS398). Immunostaining and biochemical studies confirmed the presence of VGF in the gastric neuronal cells. TLQP-21, injected i.c.v. (2-32 nmol per rat), significantly decreased gastric emptying by about 40%. This effect was significantly (P < 0.05) blocked by i.c.v. injection of indomethacin, suggesting that, also in vivo, this peptide acts in the brain stimulating PG release. CONCLUSIONS AND IMPLICATIONS The present results demonstrate that this VGF-derived peptide plays a central and local role in the regulation of rat gastric motor functions.
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Affiliation(s)
- C Severini
- Institute of Neurobiology and Molecular Medicine, 00143 Rome, Italy.
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Tanaka Y, Sekiguchi F, Hong H, Kawabata A. PAR2 triggers IL-8 release via MEK/ERK and PI3-kinase/Akt pathways in GI epithelial cells. Biochem Biophys Res Commun 2008; 377:622-626. [PMID: 18854173 DOI: 10.1016/j.bbrc.2008.10.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Accepted: 10/07/2008] [Indexed: 12/18/2022]
Abstract
Proteinase-activated receptor-2 (PAR2) plays pro-inflammatory roles in many organs including the gastrointestinal (GI) tract. To clarify the downstream pro-inflammatory signaling of PAR2 in the GI tract, we examined interleukin-8 (IL-8) release and the underlying cellular signaling following PAR2 stimulation in human colorectal cancer-derived HCT-15 cells and human gastric adenocarcinoma-derived MKN-45 cells. A PAR2-activating peptide, but not a PAR2-inactive scrambled peptide or a PAR1- activating peptide, caused IL-8 release in these GI epithelial cells. The PAR2-triggered IL-8 release was suppressed by inhibitors of MEK (U0126) or PI3-kinase (LY294002), and PAR2 stimulation indeed activated the downstream kinases, ERK and Akt. U0126 blocked the phosphorylation of ERK, but not Akt, and LY294002 blocked the phosphorylation of Akt, but not ERK. Together, PAR2 triggers IL-8 release via two independent signaling pathways, MEK/ERK and PI3-kinase/Akt, suggesting a role of PAR2 as a pro-inflammatory receptor in the GI tract.
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Affiliation(s)
- Yusuke Tanaka
- Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan
| | - Fumiko Sekiguchi
- Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan
| | - Hao Hong
- Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan
| | - Atsufumi Kawabata
- Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan.
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Tennant GM, Wadsworth RM, Kennedy S. PAR-2 mediates increased inflammatory cell adhesion and neointima formation following vascular injury in the mouse. Atherosclerosis 2008; 198:57-64. [DOI: 10.1016/j.atherosclerosis.2007.09.043] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2007] [Revised: 09/21/2007] [Accepted: 09/27/2007] [Indexed: 11/29/2022]
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Kawabata A, Matsunami M, Sekiguchi F. Gastrointestinal roles for proteinase-activated receptors in health and disease. Br J Pharmacol 2007; 153 Suppl 1:S230-40. [PMID: 17994114 DOI: 10.1038/sj.bjp.0707491] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
It has been almost a decade since the molecular cloning of all four members of the proteinase-activated receptor (PAR) family was completed. This unique family of G protein-coupled receptors (GPCRs) mediates specific cellular actions of various endogenous proteinases including thrombin, trypsin, tryptase, etc. and also certain exogenous enzymes. Increasing evidence has been clarifying the emerging roles played by PARs in health and disease. PARs, particularly PAR1 and PAR2, are distributed throughout the gastrointestinal (GI) tract, modulating various GI functions. One of the most important GI functions of PARs is regulation of exocrine secretion in the salivary glands, pancreas and GI mucosal epithelium. PARs also modulate motility of GI smooth muscle, involving multiple mechanisms. PAR2 appears to play dual roles in pancreatitis and related pain, being pro-inflammatory/pro-nociceptive and anti-inflammatory/anti-nociceptive. Similarly, dual roles for PAR1 and PAR2 have been demonstrated in mucosal inflammation/damage throughout the GI tract. There is also fundamental and clinical evidence for involvement of PAR2 in colonic pain. PARs are thus considered key molecules in regulation of GI functions and targets for development of drugs for treatment of various GI diseases.
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Affiliation(s)
- A Kawabata
- Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, Higashi-Osaka, Japan.
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Kubo S, Ishiki T, Doe I, Sekiguchi F, Nishikawa H, Kawai K, Matsui H, Kawabata A. Distinct activity of peptide mimetic intracellular ligands (pepducins) for proteinase-activated receptor-1 in multiple cells/tissues. Ann N Y Acad Sci 2007; 1091:445-59. [PMID: 17341635 DOI: 10.1196/annals.1378.087] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Proteinase-activated receptor-1 (PAR1), a G protein-coupled receptor (GPCR) for thrombin, can be activated not only by PAR1-activating peptides (PAR1APs) based on the N-terminal cryptic tethered ligand sequence but also by an N-palmitoylated (Pal) peptide, Pal-RCLSSSAVANRSKKSRALF-amide (P1pal-19), based on the intracellular loop 3 of PAR1, designated pepducin, in human platelets or PAR1-transfected cells. The present article evaluated the actions of P1pal-19 and also the shorter peptide, Pal-RCLSSSAVANRS-amide (P1pal-12), known as a possible PAR1 antagonist, in multiple cells/tissues that naturally express PAR1. P1pal-19 as well as a PAR1AP, TFLLR-amide, evoked cytosolic Ca(2+) mobilization in cultured human lung epithelial cells (A549) and rat gastric mucosal epithelial cells (RGM1). P1pal-19 and TFLLR-amide, but not a PAR2-activating peptide, SLIGRL-amide, caused delayed prostaglandin E(2) formation in RGM1 cells. P1pal-19, like TFLLR-amide, produced endothelial NO-dependent relaxation in rat aorta and epithelial prostanoid-dependent relaxation in mouse bronchus. The P1pal-19-induced relaxation remained constant even after desensitization of PAR1 with TFLLR-amide in either tissue. P1pal-19 failed to mimic the contractile effects of TFLLR-amide in the endothelium-denuded preparations of rat aorta or superior mesenteric artery and the rat gastric longitudinal smooth muscle strips. P1pal-12 partially inhibited the vasorelaxation caused by TFLLR-amide and P1pal-19, but not SLIGRL-amide, in the rat aorta. Our data thus indicate that P1pal-19 is capable of mimicking the effects of PAR1APs in the endothelial and epithelial, but not smooth muscle, cells/tissues, and suggest that P1pal-12 may act as a PAR1 antagonist in the vascular endothelium.
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Affiliation(s)
- Satoko Kubo
- Division of Physiology and Pathophysiology, School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan
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Kawabata A. [Proteinase-activated receptors and gastrointestinal functions]. Nihon Yakurigaku Zasshi 2006; 128:82-7. [PMID: 16943642 DOI: 10.1254/fpj.128.82] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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