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Sun Y, Oami T, Liang Z, Miniet AA, Burd EM, Ford ML, Coopersmith CM. Membrane Permeant Inhibitor of Myosin Light Chain Kinase Worsens Survival in Murine Polymicrobial Sepsis. Shock 2021; 56:621-628. [PMID: 33606476 PMCID: PMC8368082 DOI: 10.1097/shk.0000000000001759] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
ABSTRACT Sepsis-induced intestinal hyperpermeability is mediated by disruption of the epithelial tight junction, which is closely associated with the peri-junctional actin-myosin ring. Genetic deletion of myosin light chain kinase (MLCK) reverses intestinal hyperpermeability and improves survival in a murine model of intra-abdominal sepsis. In an attempt to determine whether these findings could be translated using a more clinically relevant strategy, this study aimed to determine if pharmacologic inhibition of MLCK using the membrane permeant inhibitor of MLCK (PIK) improved gut barrier function and survival following sepsis. C57BL/6 mice underwent cecal ligation and puncture to induce sepsis and were then randomized to receive either PIK or vehicle. Unexpectedly, PIK significantly worsened 7-day survival following sepsis (24% vs. 62%). The three pathways of intestinal permeability were then interrogated by orally gavaging septic mice with creatinine (6Å), FD-4 (28Å), and rhodamine70 (120Å) and assaying their appearance in the bloodstream. PIK led to increased permeability in the leak pathway with higher levels of FD-4 in the bloodstream compared to septic mice given vehicle. In contrast, no differences were detected in the pore or unrestricted pathways of permeability. Examination of jejunal tight junctions for potential mechanisms underlying increased leak permeability revealed that mice that received PIK had increased phosphorylated MLC without alterations in occludin, ZO-1, or JAM-A. PIK administration was not associated with significant differences in systemic or peritoneal bacterial burden, cytokines, splenic or Peyer's Patches immune cells or intestinal integrity. These results demonstrate that pharmacologic inhibition of MLCK unexpectedly increases mortality, associated with worsened intestinal permeability through the leak pathway, and suggest caution is required in targeting the gut barrier as a potential therapy in sepsis.
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Affiliation(s)
- Yini Sun
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, Georgia
- Department of Critical Care Medicine, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Takehiko Oami
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, Georgia
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Zhe Liang
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, Georgia
| | - Ashley A Miniet
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia
| | - Eileen M Burd
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia
| | - Mandy L Ford
- Department of Surgery and Emory Transplant Center, Emory University School of Medicine, Atlanta, Georgia
| | - Craig M Coopersmith
- Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, Georgia
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Meyer B, Chiaravalli J, Gellenoncourt S, Brownridge P, Bryne DP, Daly LA, Grauslys A, Walter M, Agou F, Chakrabarti LA, Craik CS, Eyers CE, Eyers PA, Gambin Y, Jones AR, Sierecki E, Verdin E, Vignuzzi M, Emmott E. Characterising proteolysis during SARS-CoV-2 infection identifies viral cleavage sites and cellular targets with therapeutic potential. Nat Commun 2021; 12:5553. [PMID: 34548480 PMCID: PMC8455558 DOI: 10.1038/s41467-021-25796-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 08/24/2021] [Indexed: 02/08/2023] Open
Abstract
SARS-CoV-2 is the causative agent behind the COVID-19 pandemic, responsible for over 170 million infections, and over 3.7 million deaths worldwide. Efforts to test, treat and vaccinate against this pathogen all benefit from an improved understanding of the basic biology of SARS-CoV-2. Both viral and cellular proteases play a crucial role in SARS-CoV-2 replication. Here, we study proteolytic cleavage of viral and cellular proteins in two cell line models of SARS-CoV-2 replication using mass spectrometry to identify protein neo-N-termini generated through protease activity. We identify previously unknown cleavage sites in multiple viral proteins, including major antigens S and N: the main targets for vaccine and antibody testing efforts. We discover significant increases in cellular cleavage events consistent with cleavage by SARS-CoV-2 main protease, and identify 14 potential high-confidence substrates of the main and papain-like proteases. We show that siRNA depletion of these cellular proteins inhibits SARS-CoV-2 replication, and that drugs targeting two of these proteins: the tyrosine kinase SRC and Ser/Thr kinase MYLK, show a dose-dependent reduction in SARS-CoV-2 titres. Overall, our study provides a powerful resource to understand proteolysis in the context of viral infection, and to inform the development of targeted strategies to inhibit SARS-CoV-2 and treat COVID-19.
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Affiliation(s)
- Bjoern Meyer
- Viral Populations and Pathogenesis Unit, CNRS, UMR 3569, Institut Pasteur, CEDEX 15, Paris, France
| | - Jeanne Chiaravalli
- Chemogenomic and Biological Screening Core Facility, C2RT, Departments of Cell Biology & Infection and of Structural Biology & Chemistry, Institut Pasteur, CEDEX 15, Paris, France
| | - Stacy Gellenoncourt
- CIVIC Group, Virus & Immunity Unit, Institut Pasteur and CNRS, UMR 3569, Paris, France
| | - Philip Brownridge
- Centre for Proteome Research, Department of Biochemistry & Systems Biology, Institute of Systems, Molecular & Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Dominic P Bryne
- Department of Biochemistry & Systems Biology, Institute of Systems, Molecular & Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Leonard A Daly
- Centre for Proteome Research, Department of Biochemistry & Systems Biology, Institute of Systems, Molecular & Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Arturas Grauslys
- Computational Biology Facility, LIV-SRF, Institute of Systems, Molecular & Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Marius Walter
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Fabrice Agou
- Chemogenomic and Biological Screening Core Facility, C2RT, Departments of Cell Biology & Infection and of Structural Biology & Chemistry, Institut Pasteur, CEDEX 15, Paris, France
| | - Lisa A Chakrabarti
- CIVIC Group, Virus & Immunity Unit, Institut Pasteur and CNRS, UMR 3569, Paris, France
| | - Charles S Craik
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
| | - Claire E Eyers
- Centre for Proteome Research, Department of Biochemistry & Systems Biology, Institute of Systems, Molecular & Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Patrick A Eyers
- Department of Biochemistry & Systems Biology, Institute of Systems, Molecular & Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Yann Gambin
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Andrew R Jones
- Department of Biochemistry & Systems Biology, Institute of Systems, Molecular & Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Emma Sierecki
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Eric Verdin
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Marco Vignuzzi
- Viral Populations and Pathogenesis Unit, CNRS, UMR 3569, Institut Pasteur, CEDEX 15, Paris, France
| | - Edward Emmott
- Centre for Proteome Research, Department of Biochemistry & Systems Biology, Institute of Systems, Molecular & Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK.
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Younis W, Schini-Kerth VB, Junior AG, Nocchi SR, Silva DB, Roberts RE. Endothelium-independent vasorelaxant effect of Asphodelus tenuifolius Cav. via inhibition of myosin light chain kinase activity in the porcine coronary artery. J Ethnopharmacol 2021; 269:113693. [PMID: 33326818 DOI: 10.1016/j.jep.2020.113693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 04/11/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Asphodelus tenuifolius Cav. (Asphodelaceae), a wild, terrestrial, annual stemless herb, is widely used in traditional medicine for the treatment of hypertension, diabetes, atherosclerosis and circulatory problems. A previous research study from our laboratory revealed that A. tenuifolius has beneficial effects in reducing blood pressure and improves aortic endothelial dysfunction in chronically glucose fed rats. Despite the fact that A. tenuifolius reduces blood pressure and improves endothelial function in vivo, there are no detailed studies about its possible mechanism of action. AIM OF THE STUDY This study was designed to provide pharmacological basis and mechanism of action for the traditional use of A. tenuifolius in hypertension and circulatory problems. We explored the vasorelaxant effect of A. tenuifolius and its underlying vasorelaxation mechanism in porcine coronary artery rings. MATERIALS AND METHODS Aqueous methanolic crude extract of A. tenuifolius was prepared by maceration process and then activity guided fractionation was carried out by using different polarity based solvents. Phytochemical studies were carried out using LC-DAD-MS. Segments of porcine distal coronary artery were set up in a wire myograph for isometric force measurements. Extract/fractions of A. tenuifolius seeds were tested for vasodilator activity by measurement of changes in tone after pre-contraction with the thromboxane mimetic U46619 in the presence or absence of inhibitors of intracellular signaling cascades. RESULTS Crude extract/fractions of A. tenuifolius produced dose dependent endothelium independent vasorelaxant response in coronary rings, whereas, the butanol fraction of A. tenuifolius (BS-AT) produced the largest relaxation response with 100% relaxation at 1 mg/ml, therefore the mechanism of relaxation of this fraction was determined. The relaxation to BS-AT was unaffected by removal of the endothelium, pre-contraction with KCl, or the presence of the non-selective potassium channel blocker tetraethylammonium, indicating that the relaxation was endothelium-independent, and does not involve activation of potassium channels. BS-AT (1 mg/ml) inhibited the contractile response to calcium,the L-type calcium channel activator BAY K8664,and ionomycin, indicating that it inhibits calcium-induced contractions. The relaxation response to BS-AT was attenuated in the absence of extracellular calcium. However, relaxations to BS-AT were also reduced after deletion of calcium from intracellular stores with cyclopiazonic acid. Incubation with 1 mg/ml BS-AT also inhibited phosphorylation of myosin light chains in homogenates of coronary artery. CONCLUSION The butanol extract of Asphodelus tenuifolius produces a large endothelium-independent relaxation of the porcine coronary artery through inhibition of calcium-induced contractions. The effect appears to be downstream of calcium influx, possibly through inhibition of myosin light chain kinase. This study supports previous studies demonstrating that A. tenuifolius reduces blood pressure. Future studies will aim to determine the active compounds underlying this response.
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Affiliation(s)
- Waqas Younis
- Laboratory of Cardiovascular Research and Integrative Pharmacology, College of Pharmacy, University of Sargodha, Sargodha, 40100, Pakistan; Pharmacology Research Group, School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, United Kingdom
| | - V B Schini-Kerth
- UMR 1260 INSERM Nanomédecine Régénérative Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Arquimedes Gasparotto Junior
- Laboratory of Electrophysiology and Cardiovascular Pharmacology, Federal University of Grande Dourados (UFGD), P.O. Box 533, 79.804-970, Dourados, MS, Brazil
| | - Samara Requena Nocchi
- Laboratório de Produtos Naturais e Espectrometria de Massas (LaPNEM), Faculdade de Ciências Farmacêuticas, Alimentos e Nutrição (FACFAN), Universidade Federal do Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Denise Brentan Silva
- Laboratório de Produtos Naturais e Espectrometria de Massas (LaPNEM), Faculdade de Ciências Farmacêuticas, Alimentos e Nutrição (FACFAN), Universidade Federal do Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Richard E Roberts
- Pharmacology Research Group, School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, United Kingdom.
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Sharma U, Olson RK, Erhart FN, Zhang L, Meng J, Segura B, Banerjee S, Sharma M, Saluja AK, Ramakrishnan S, Abreu MT, Roy S. Prescription Opioids induce Gut Dysbiosis and Exacerbate Colitis in a Murine Model of Inflammatory Bowel Disease. J Crohns Colitis 2020; 14:801-817. [PMID: 31773170 PMCID: PMC7346895 DOI: 10.1093/ecco-jcc/jjz188] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Opioids are the most prescribed analgesics for pain in inflammatory bowel diseases [IBD]; however, the consequences of opioid use on IBD severity are not well defined. This is the first study investigating consequences of hydromorphone in both dextran sodium sulphate [DSS]-induced colitis and spontaneous colitis (IL-10 knockout [IL-10-/-]) mouse models of IBD. METHODS To determine the consequences of opioids on IBD pathogenesis, wild-type [WT] mice were treated with clinically relevant doses of hydromorphone and colitis was induced via 3% DSS in drinking water for 5 days. In parallel we also determined the consequences of opioids in a spontaneous colitis model. RESULTS Hydromorphone and DSS independently induced barrier dysfunction, bacterial translocation, disruption of tight junction organisation and increased intestinal and systemic inflammation, which were exacerbated in mice receiving hydromorphone in combination with DSS. Hydromorphone + DSS-treated mice exhibited significant microbial dysbiosis. Predictive metagenomic analysis of the gut microbiota revealed high abundance in the bacterial communities associated with virulence, antibiotic resistance, toxin production, and inflammatory properties. Hydromorphone modulates tight junction organisation in a myosin light chain kinase [MLCK]-dependent manner. Treatment with MLCK inhibitor ML-7 ameliorates the detrimental effects of hydromorphone on DSS-induced colitis and thus decreases severity of IBD. Similarly, we demonstrated that hydromorphone treatment in IL-10-/- mice resulted in accelerated clinical manifestations of colitis compared with control mice. CONCLUSIONS Opioids used for pain management in IBD accelerate IBD progression by dysregulation of the gut microbiota, leading to expansion of pathogenic bacteria, translocation of bacteria, immune deregulation and sustained inflammation.
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Affiliation(s)
- Umakant Sharma
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | | | | | - Li Zhang
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Jingjing Meng
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Bradley Segura
- Department of Surgery, University of Minnesota, Minneapolis, MN, USA
| | - Santanu Banerjee
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Madhulika Sharma
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Ashok Kumar Saluja
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Sundaram Ramakrishnan
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Maria T Abreu
- Division of Gastroenterology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Sabita Roy
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
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Deng JT, Bhaidani S, Sutherland C, MacDonald JA, Walsh MP. Rho-associated kinase and zipper-interacting protein kinase, but not myosin light chain kinase, are involved in the regulation of myosin phosphorylation in serum-stimulated human arterial smooth muscle cells. PLoS One 2019; 14:e0226406. [PMID: 31834925 PMCID: PMC6910671 DOI: 10.1371/journal.pone.0226406] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 11/26/2019] [Indexed: 01/09/2023] Open
Abstract
Myosin regulatory light chain (LC20) phosphorylation plays an important role in vascular smooth muscle contraction and cell migration. Ca2+/calmodulin-dependent myosin light chain kinase (MLCK) phosphorylates LC20 (its only known substrate) exclusively at S19. Rho-associated kinase (ROCK) and zipper-interacting protein kinase (ZIPK) have been implicated in the regulation of LC20 phosphorylation via direct phosphorylation of LC20 at T18 and S19 and indirectly via phosphorylation of MYPT1 (the myosin targeting subunit of myosin light chain phosphatase, MLCP) and Par-4 (prostate-apoptosis response-4). Phosphorylation of MYPT1 at T696 and T853 inhibits MLCP activity whereas phosphorylation of Par-4 at T163 disrupts its interaction with MYPT1, exposing the sites of phosphorylation in MYPT1 and leading to MLCP inhibition. To evaluate the roles of MLCK, ROCK and ZIPK in these phosphorylation events, we investigated the time courses of phosphorylation of LC20, MYPT1 and Par-4 in serum-stimulated human vascular smooth muscle cells (from coronary and umbilical arteries), and examined the effects of siRNA-mediated MLCK, ROCK and ZIPK knockdown and pharmacological inhibition on these phosphorylation events. Serum stimulation induced rapid phosphorylation of LC20 at T18 and S19, MYPT1 at T696 and T853, and Par-4 at T163, peaking within 30–120 s. MLCK knockdown or inhibition, or Ca2+ chelation with EGTA, had no effect on serum-induced LC20 phosphorylation. ROCK knockdown decreased the levels of phosphorylation of LC20 at T18 and S19, of MYPT1 at T696 and T853, and of Par-4 at T163, whereas ZIPK knockdown decreased LC20 diphosphorylation, but increased phosphorylation of MYPT1 at T696 and T853 and of Par-4 at T163. ROCK inhibition with GSK429286A reduced serum-induced phosphorylation of LC20 at T18 and S19, MYPT1 at T853 and Par-4 at T163, while ZIPK inhibition by HS38 reduced only LC20 diphosphorylation. We also demonstrated that serum stimulation induced phosphorylation (activation) of ZIPK, which was inhibited by ROCK and ZIPK down-regulation and inhibition. Finally, basal phosphorylation of LC20 in the absence of serum stimulation was unaffected by MLCK, ROCK or ZIPK knockdown or inhibition. We conclude that: (i) serum stimulation of cultured human arterial smooth muscle cells results in rapid phosphorylation of LC20, MYPT1, Par-4 and ZIPK, in contrast to the slower phosphorylation of kinases and other proteins involved in other signaling pathways (Akt, ERK1/2, p38 MAPK and HSP27), (ii) ROCK and ZIPK, but not MLCK, are involved in serum-induced phosphorylation of LC20, (iii) ROCK, but not ZIPK, directly phosphorylates MYPT1 at T853 and Par-4 at T163 in response to serum stimulation, (iv) ZIPK phosphorylation is enhanced by serum stimulation and involves phosphorylation by ROCK and autophosphorylation, and (v) basal phosphorylation of LC20 under serum-free conditions is not attributable to MLCK, ROCK or ZIPK.
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Affiliation(s)
- Jing-Ti Deng
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sabreena Bhaidani
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Cindy Sutherland
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Justin A. MacDonald
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Michael P. Walsh
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- * E-mail:
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Wang J, Zhang C, Li C, Zhao D, Li S, Ma L, Cui Y, Wei X, Zhao Y, Gao Y. MicroRNA-92a promotes vascular smooth muscle cell proliferation and migration through the ROCK/MLCK signalling pathway. J Cell Mol Med 2019; 23:3696-3710. [PMID: 30907506 PMCID: PMC6484312 DOI: 10.1111/jcmm.14274] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 02/12/2019] [Accepted: 02/23/2019] [Indexed: 12/31/2022] Open
Abstract
To identify the interaction between known regulators of atherosclerosis, microRNA-92a (miR-92a), Rho-associated coiled-coil-forming kinase (ROCK) and myosin light chain kinase (MLCK), we examined their expressions during proliferation and migration of platelet-derived growth factor-BB (PDGF-BB)-regulated vascular smooth muscle cells (VSMCs), both in vivo and in vitro. During the formation of atherosclerosis plaque in mice, a parallel increase in expression levels of MLCK and miR-92a was observed while miR-92a expression was reduced in ML-7 (an inhibitor of MLCK) treated mice and in MLCK-deficient VSMCs. In vitro results indicated that both MLCK and miR-92a shared the same signalling pathway. Transfection of miR-92a mimic partially restored the effect of MLCK's deficiency and antagonized the effect of Y27632 (an inhibitor of ROCK) on the down-regulation of VSMCs activities. ML-7 increased the expression of Kruppel-like factor 4 (KLF4, a target of miR-92a), and siRNA-KLF4 increased VSMCs' activity level. Consistently, inhibition of either MLCK or ROCK enhanced the KLF4 expression. Moreover, we observed that ROCK/MLCK up-regulated miR-92a expression in VSMCs through signal transducer and activator of transcription 3 (STAT3) activation. In conclusion, the activation of ROCK/STAT3 and/or MLCK/STAT3 may up-regulate miR-92a expression, which subsequently inhibits KLF4 expression and promotes PDGF-BB-mediated proliferation and migration of VSMCs. This new downstream node in the ROCK/MLCK signalling pathway may offer a potential intervention target for treatment of atherosclerosis.
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Affiliation(s)
- Jingyu Wang
- Department of Biochemistry and Molecular Biology, College of Basic Medical SciencesDalian Medical UniversityDalianChina
| | - Chenxu Zhang
- Department of Biochemistry and Molecular Biology, College of Basic Medical SciencesDalian Medical UniversityDalianChina
| | - Cai Li
- Department of Biochemistry and Molecular Biology, College of Basic Medical SciencesDalian Medical UniversityDalianChina
| | - Dandan Zhao
- Department of Biochemistry and Molecular Biology, College of Basic Medical SciencesDalian Medical UniversityDalianChina
| | - Shuyao Li
- Department of Biochemistry and Molecular Biology, College of Basic Medical SciencesDalian Medical UniversityDalianChina
| | - Le Ma
- College of StomatologyDalian Medical UniversityDalianChina
| | - Ying Cui
- Department of Biochemistry and Molecular Biology, College of Basic Medical SciencesDalian Medical UniversityDalianChina
- Liaoning Provincial Key Lab of Medical Molecular BiologyDalian Medical UniversityDalianChina
| | - Xiaoqing Wei
- Department of Biochemistry and Molecular Biology, College of Basic Medical SciencesDalian Medical UniversityDalianChina
- Liaoning Provincial Key Lab of Medical Molecular BiologyDalian Medical UniversityDalianChina
| | - Ying Zhao
- Department of Biochemistry and Molecular Biology, College of Basic Medical SciencesDalian Medical UniversityDalianChina
- Liaoning Provincial Key Lab of Medical Molecular BiologyDalian Medical UniversityDalianChina
| | - Ying Gao
- Department of Biochemistry and Molecular Biology, College of Basic Medical SciencesDalian Medical UniversityDalianChina
- Liaoning Provincial Key Lab of Medical Molecular BiologyDalian Medical UniversityDalianChina
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Miao W, Wu X, Wang K, Wang W, Wang Y, Li Z, Liu J, Li L, Peng L. Sodium Butyrate Promotes Reassembly of Tight Junctions in Caco-2 Monolayers Involving Inhibition of MLCK/MLC2 Pathway and Phosphorylation of PKCβ2. Int J Mol Sci 2016; 17:ijms17101696. [PMID: 27735862 PMCID: PMC5085728 DOI: 10.3390/ijms17101696] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 09/15/2016] [Accepted: 09/26/2016] [Indexed: 12/17/2022] Open
Abstract
As a physiological small molecular product from the microbial fermentation of dietary fibers, butyrate plays an important role in maintaining intestinal health. Our previous works have proved that the effect of sodium butyrate (NaB) on the intestinal barrier function is mediated by activation of AMP-activated protein kinase (AMPK). However, the detailed pathway involved remains unknown. Using the calcium switch assay in the Caco-2 cell monolayer model, we found here that NaB activated AMPK mainly by increasing the calcium level, but not the ATP concentration, via promoting store-operated calcium entry (SOCE). Upon the activation of AMPK, NaB promoted the reassembly of tight junctions (TJs) based on reducing the phosphorylation of myosin II regulatory light chain (MLC2) at Ser19 and increasing phosphorylation of protein kinase C β2 (PKCβ2) at Ser660. Inhibiting (protein kinase C β) PKCβ blocked the reassembly of TJs induced by NaB in the barrier monolayer model. These results indicated that NaB could activate the calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ) pathway to mediate AMPK phosphorylating, which then inhibited the phosphorylation of MLC2 and promoted the phosphorylation of PKCβ2, respectively, so that the downstream molecules of AMPK coordinately contributed to the reassembly of TJs in the Caco-2 barrier model. These results suggested a potential mechanism of butyrate for intestine homeostasis and protection.
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Affiliation(s)
- Wei Miao
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Xiujuan Wu
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Kang Wang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Wenjing Wang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Yumei Wang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Zhigang Li
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Jingjing Liu
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Li Li
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Luying Peng
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
- Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai 200092, China.
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8
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Lai S, Collins BC, Colson BA, Kararigas G, Lowe DA. Estradiol modulates myosin regulatory light chain phosphorylation and contractility in skeletal muscle of female mice. Am J Physiol Endocrinol Metab 2016; 310:E724-33. [PMID: 26956186 PMCID: PMC4867308 DOI: 10.1152/ajpendo.00439.2015] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 03/02/2016] [Indexed: 11/22/2022]
Abstract
Impairment of skeletal muscle function has been associated with changes in ovarian hormones, especially estradiol. To elucidate mechanisms of estradiol on skeletal muscle strength, the hormone's effects on phosphorylation of the myosin regulatory light chain (pRLC) and muscle contractility were investigated, hypothesizing an estradiol-specific beneficial impact. In a skeletal muscle cell line, C2C12, pRLC was increased by 17β-estradiol (E2) in a concentration-dependent manner. In skeletal muscles of C57BL/6 mice that were E2 deficient via ovariectomy (OVX), pRLC was lower than that from ovary-intact, sham-operated mice (Sham). The reduced pRLC in OVX muscle was reversed by in vivo E2 treatment. Posttetanic potentiation (PTP) of muscle from OVX mice was low compared with that from Sham mice, and this decrement was reversed by acute E2 treatment, demonstrating physiological consequence. Western blot of those muscles revealed that low PTP corresponded with low pRLC and higher PTP with greater pRLC. We aimed to elucidate signaling pathways affecting E2-mediated pRLC using a kinase inhibitor library and C2C12 cells as well as a specific myosin light chain kinase inhibitor in muscles. PI3K/Akt, MAPK, and CamKII were identified as candidate kinases sensitive to E2 in terms of phosphorylating RLC. Applying siRNA strategy in C2C12 cells, pRLC triggered by E2 was found to be mediated by estrogen receptor-β and the G protein-coupled estrogen receptor. Together, these results provide evidence that E2 modulates myosin pRLC in skeletal muscle and is one mechanism by which this hormone can affect muscle contractility in females.
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Affiliation(s)
- Shaojuan Lai
- Programs in Rehabilitation Sciences and Physical Therapy, Department of Physical Medicine and Rehabilitation, Medical School, University of Minnesota, Minneapolis, Minnesota; College of Biological Engineering, Henan University of Technology, Zhengzhou, Henan, China; and
| | - Brittany C Collins
- Programs in Rehabilitation Sciences and Physical Therapy, Department of Physical Medicine and Rehabilitation, Medical School, University of Minnesota, Minneapolis, Minnesota
| | - Brett A Colson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Georgios Kararigas
- Institute of Gender in Medicine, Charite University Hospital, and German Centre for Cardiovascular Research (DZHK), Partner Site, Berlin, Germany
| | - Dawn A Lowe
- Programs in Rehabilitation Sciences and Physical Therapy, Department of Physical Medicine and Rehabilitation, Medical School, University of Minnesota, Minneapolis, Minnesota;
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9
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Tanaka H, Wang HH, Thatcher SE, Hagiwara H, Takano-Ohmuro H, Kohama K. Electron microscopic examination of podosomes induced by phorbol 12, 13 dibutyrate on the surface of A7r5 cells. J Pharmacol Sci 2015; 128:78-82. [PMID: 25986486 DOI: 10.1016/j.jphs.2015.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/03/2015] [Accepted: 03/04/2015] [Indexed: 11/17/2022] Open
Abstract
The role of myosin light chain kinase (MLCK) in inducing podosomes was examined by confocal and electron microscopy. Removal of myosin from the actin core of podosomes using blebbistatin, a myosin inhibitor, resulted in the formation of smaller podosomes. Downregulation of MLCK by the transfection of MLCK small interfering RNA (siRNA) led to the failure of podosome formation. However, ML-7, an inhibitor of the kinase activity of MLCK, failed to inhibit podosome formation. Based on our previous report (Thatcher et al. J.Pharm.Sci. 116 116-127, 2011), we outlined the important role of the actin-binding activity of MLCK in producing smaller podosomes.
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Affiliation(s)
- Hideyuki Tanaka
- Department of Anatomy, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
| | - Hong-Hui Wang
- Department of Cellular and Molecular Medicine, University of California San Diego, 9500 Gillman Drive 0651, La Jolla, CA 92093-0651, USA; College of Biology, Hunan University, No.1 Denggao Road, Yuelushan, Changsha, Hunan 410082, PR China
| | - Sean E Thatcher
- Department of Nutritional Sciences, University of Kentucky, Charles T.Wethington Bldg, 900 South Limestone, Lexington, KY 40536-0200, USA
| | - Haruo Hagiwara
- Department of Anatomy, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
| | - Hiromi Takano-Ohmuro
- Research Institute of Pharmaceutical Sciences, Musashino University, Nishitokyo, Tokyo 202-8585, Japan
| | - Kazuhiro Kohama
- Research Institute of Pharmaceutical Sciences, Musashino University, Nishitokyo, Tokyo 202-8585, Japan.
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10
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McCrudden CM, O’Rourke MG, Cherry KE, Yuen HF, O’Rourke D, Babur M, Telfer BA, Thomas HD, Keane P, Nambirajan T, Hagan C, O’Sullivan JM, Shaw C, Williams KJ, Curtin NJ, Hirst DG, Robson T. Vasoactivity of rucaparib, a PARP-1 inhibitor, is a complex process that involves myosin light chain kinase, P2 receptors, and PARP itself. PLoS One 2015; 10:e0118187. [PMID: 25689628 PMCID: PMC4331495 DOI: 10.1371/journal.pone.0118187] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 01/05/2015] [Indexed: 01/01/2023] Open
Abstract
Therapeutic inhibition of poly(ADP-ribose) polymerase (PARP), as monotherapy or to supplement the potencies of other agents, is a promising strategy in cancer treatment. We previously reported that the first PARP inhibitor to enter clinical trial, rucaparib (AG014699), induced vasodilation in vivo in xenografts, potentiating response to temozolomide. We now report that rucaparib inhibits the activity of the muscle contraction mediator myosin light chain kinase (MLCK) 10-fold more potently than its commercially available inhibitor ML-9. Moreover, rucaparib produces additive relaxation above the maximal degree achievable with ML-9, suggesting that MLCK inhibition is not solely responsible for dilation. Inhibition of nitric oxide synthesis using L-NMMA also failed to impact rucaparib’s activity. Rucaparib contains the nicotinamide pharmacophore, suggesting it may inhibit other NAD+-dependent processes. NAD+ exerts P2 purinergic receptor-dependent inhibition of smooth muscle contraction. Indiscriminate blockade of the P2 purinergic receptors with suramin abrogated rucaparib-induced vasodilation in rat arterial tissue without affecting ML-9-evoked dilation, although the specific receptor subtypes responsible have not been unequivocally identified. Furthermore, dorsal window chamber and real time tumor vessel perfusion analyses in PARP-1-/- mice indicate a potential role for PARP in dilation of tumor-recruited vessels. Finally, rucaparib provoked relaxation in 70% of patient-derived tumor-associated vessels. These data provide tantalising evidence of the complexity of the mechanism underlying rucaparib-mediated vasodilation.
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Affiliation(s)
- Cian M. McCrudden
- School of Pharmacy, Queen’s University Belfast, Belfast, United Kingdom
- * E-mail:
| | | | - Kim E. Cherry
- School of Pharmacy, Queen’s University Belfast, Belfast, United Kingdom
| | - Hiu-Fung Yuen
- Centre for Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, United Kingdom
| | - Declan O’Rourke
- Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Muhammad Babur
- Manchester Pharmacy School, The University of Manchester, Manchester, United Kingdom
| | - Brian A. Telfer
- Manchester Pharmacy School, The University of Manchester, Manchester, United Kingdom
| | - Huw D. Thomas
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Patrick Keane
- Belfast Health and Social Care Trust, Belfast, United Kingdom
| | | | - Chris Hagan
- Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Joe M. O’Sullivan
- Centre for Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, United Kingdom
- Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Chris Shaw
- School of Pharmacy, Queen’s University Belfast, Belfast, United Kingdom
| | - Kaye J. Williams
- Manchester Pharmacy School, The University of Manchester, Manchester, United Kingdom
| | - Nicola J. Curtin
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - David G. Hirst
- School of Pharmacy, Queen’s University Belfast, Belfast, United Kingdom
| | - Tracy Robson
- School of Pharmacy, Queen’s University Belfast, Belfast, United Kingdom
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11
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Bang J, Jang M, Huh JH, Na JW, Shim M, Carlson BA, Tobe R, Tsuji PA, Gladyshev VN, Hatfield DL, Lee BJ. Deficiency of the 15-kDa selenoprotein led to cytoskeleton remodeling and non-apoptotic membrane blebbing through a RhoA/ROCK pathway. Biochem Biophys Res Commun 2015; 456:884-90. [PMID: 25529450 PMCID: PMC4758352 DOI: 10.1016/j.bbrc.2014.12.059] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 12/11/2014] [Indexed: 01/20/2023]
Abstract
The 15-kDa selenoprotein (Sep15) has been implicated in etiology of some types of cancer. Herein, inducible RNAi cell lines were established and cell morphology and motility were analyzed. The majority of Sep15-deficient cells (>95%) formed membrane blebs in a dynamic manner. Blebbing cells transformed cell morphology from a normal flat spindle shape to a spherical morphology. In blebbing cells, actin fibers moved to the cell periphery, covering and obscuring visualization of α-tubulin. Bleb formation was suppressed by the inhibitors of Rho-associated protein kinase (ROCK), RhoA or myosin light chain (MLC), restoring blebbing cells to wild-type morphology. RhoA activation and phosphorylation of myosin phosphatase target subunit 1 was induced by Sep15 knockdown. Sep15-deficient cells were non-apoptotic, and displayed a distinct relative localization of F-actin and α-tubulin from typical apoptotic blebbing cells. Our data suggest that Sep15 in Chang liver cells regulates the pathway that antagonizes RhoA/ROCK/MLC-dependent non-apoptotic bleb formation.
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Affiliation(s)
- Jeyoung Bang
- School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea; Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-742, Republic of Korea
| | - Mihyun Jang
- School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Jang Hoe Huh
- School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Ji-Woon Na
- School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Myoungsup Shim
- School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Republic of Korea
| | - Bradley A Carlson
- Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ryuta Tobe
- Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Petra A Tsuji
- Department of Biological Sciences, Towson University, Towson, MD 21252, USA
| | - Vadim N Gladyshev
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Dolph L Hatfield
- Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Byeong Jae Lee
- School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea; Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-742, Republic of Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Republic of Korea.
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12
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He Y, Wang F, Chen S, Liu M, Pan W, Li X. The Protective Effect of Radix Polygoni Multiflori on Diabetic Encephalopathy via Regulating Myosin Light Chain Kinase Expression. J Diabetes Res 2015; 2015:484721. [PMID: 26199947 PMCID: PMC4496489 DOI: 10.1155/2015/484721] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Currently there has been no effective treatment of diabetic encephalopathy. Radix Polygoni Multiflori, a famous traditional Chinese medicine, is widely used in antiaging treatment, especially in prevention and treatment of Alzheimer's diseases. In this study we tried to explore the effect of Radix Polygoni Multiflori on cognitive function among diabetic rats with demonstrated cognitive impairment. SD rats were divided into group A (control group), group B (diabetes), group C (treated with Radix Polygoni Multiflori at the dose of 2 g/kg/d), and group D (treated with same drug at the dose of 1 g/kg/d). The results showed that 8 weeks of Radix Polygoni Multiflori treatment could improve the cognitive dysfunction of diabetic rats (P < 0.01), recover the ultrastructure of hippocampal neurons, and increase the number of synapses in a dose-dependent manner. Further experiment also suggested that the neuroprotective effect of Radix Polygoni Multiflori was partly achieved by downregulating MLCK expression in hippocampus via ERK signaling.
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MESH Headings
- Animals
- Brain Diseases, Metabolic/complications
- Brain Diseases, Metabolic/prevention & control
- Cognition/drug effects
- Cognition Disorders/complications
- Cognition Disorders/prevention & control
- Diabetes Mellitus, Type 1/complications
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Diabetic Neuropathies/prevention & control
- Dose-Response Relationship, Drug
- Down-Regulation/drug effects
- Drugs, Chinese Herbal/administration & dosage
- Drugs, Chinese Herbal/therapeutic use
- Hypothalamus/drug effects
- Hypothalamus/metabolism
- Hypothalamus/ultrastructure
- MAP Kinase Signaling System/drug effects
- Male
- Maze Learning/drug effects
- Microscopy, Electron, Transmission
- Myosin-Light-Chain Kinase/antagonists & inhibitors
- Myosin-Light-Chain Kinase/chemistry
- Myosin-Light-Chain Kinase/metabolism
- Nerve Tissue Proteins/antagonists & inhibitors
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Neurons/drug effects
- Neurons/metabolism
- Neurons/ultrastructure
- Neuroprotective Agents/administration & dosage
- Neuroprotective Agents/therapeutic use
- Nootropic Agents/therapeutic use
- Rats, Sprague-Dawley
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Affiliation(s)
- Yu He
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Feng Wang
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Shiqiang Chen
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Mi Liu
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Wei Pan
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
| | - Xing Li
- Guizhou Medical University, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550025, China
- *Xing Li:
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13
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Unbekandt M, Olson MF. The actin-myosin regulatory MRCK kinases: regulation, biological functions and associations with human cancer. J Mol Med (Berl) 2014; 92:217-25. [PMID: 24553779 PMCID: PMC3940853 DOI: 10.1007/s00109-014-1133-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 01/24/2014] [Accepted: 01/27/2014] [Indexed: 12/27/2022]
Abstract
The contractile actin-myosin cytoskeleton provides much of the force required for numerous cellular activities such as motility, adhesion, cytokinesis and changes in morphology. Key elements that respond to various signal pathways are the myosin II regulatory light chains (MLC), which participate in actin-myosin contraction by modulating the ATPase activity and consequent contractile force generation mediated by myosin heavy chain heads. Considerable effort has focussed on the role of MLC kinases, and yet the contributions of the myotonic dystrophy-related Cdc42-binding kinases (MRCK) proteins in MLC phosphorylation and cytoskeleton regulation have not been well characterized. In contrast to the closely related ROCK1 and ROCK2 kinases that are regulated by the RhoA and RhoC GTPases, there is relatively little information about the CDC42-regulated MRCKα, MRCKβ and MRCKγ members of the AGC (PKA, PKG and PKC) kinase family. As well as differences in upstream activation pathways, MRCK and ROCK kinases apparently differ in the way that they spatially regulate MLC phosphorylation, which ultimately affects their influence on the organization and dynamics of the actin-myosin cytoskeleton. In this review, we will summarize the MRCK protein structures, expression patterns, small molecule inhibitors, biological functions and associations with human diseases such as cancer.
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Affiliation(s)
- Mathieu Unbekandt
- Cancer Research UK Beatson Institute, Switchback Road, Garscube Estate, Glasgow, UK G61 1BD
| | - Michael F. Olson
- Cancer Research UK Beatson Institute, Switchback Road, Garscube Estate, Glasgow, UK G61 1BD
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14
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Saphirstein RJ, Gao YZ, Jensen MH, Gallant CM, Vetterkind S, Moore JR, Morgan KG. The focal adhesion: a regulated component of aortic stiffness. PLoS One 2013; 8:e62461. [PMID: 23626821 PMCID: PMC3633884 DOI: 10.1371/journal.pone.0062461] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 03/21/2013] [Indexed: 01/16/2023] Open
Abstract
Increased aortic stiffness is an acknowledged predictor and cause of cardiovascular disease. The sources and mechanisms of vascular stiffness are not well understood, although the extracellular matrix (ECM) has been assumed to be a major component. We tested here the hypothesis that the focal adhesions (FAs) connecting the cortical cytoskeleton of vascular smooth muscle cells (VSMCs) to the matrix in the aortic wall are a component of aortic stiffness and that this component is dynamically regulated. First, we examined a model system in which magnetic tweezers could be used to monitor cellular cortical stiffness, serum-starved A7r5 aortic smooth muscle cells. Lysophosphatidic acid (LPA), an activator of myosin that increases cell contractility, increased cortical stiffness. A small molecule inhibitor of Src-dependent FA recycling, PP2, was found to significantly inhibit LPA-induced increases in cortical stiffness, as well as tension-induced increases in FA size. To directly test the applicability of these results to force and stiffness development at the level of vascular tissue, we monitored mouse aorta ring stiffness with small sinusoidal length oscillations during agonist-induced contraction. The alpha-agonist phenylephrine, which also increases myosin activation and contractility, increased tissue stress and stiffness in a PP2- and FAK inhibitor 14-attenuated manner. Subsequent phosphotyrosine screening and follow-up with phosphosite-specific antibodies confirmed that the effects of PP2 and FAK inhibitor 14 in vascular tissue involve FA proteins, including FAK, CAS, and paxillin. Thus, in the present study we identify, for the first time, the FA of the VSMC, in particular the FAK-Src signaling complex, as a significant subcellular regulator of aortic stiffness and stress.
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Affiliation(s)
- Robert J. Saphirstein
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Yuan Z. Gao
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Mikkel H. Jensen
- Department of Physics, Boston University, Boston, Massachusetts, United States of America
- Department of Physiology and Biophysics, Boston University Medical School, Boston, Massachusetts, United States of America
| | - Cynthia M. Gallant
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Susanne Vetterkind
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Jeffrey R. Moore
- Department of Physiology and Biophysics, Boston University Medical School, Boston, Massachusetts, United States of America
| | - Kathleen G. Morgan
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
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15
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Xiong YJ, Chen DP, Lv BC, Liu FF, Wang L, Lin Y. The characteristics of genistin-induced inhibitory effects on intestinal motility. Arch Pharm Res 2013; 36:345-52. [PMID: 23435915 DOI: 10.1007/s12272-013-0053-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Accepted: 01/10/2013] [Indexed: 11/26/2022]
Abstract
Genistin belongs to isoflavones. Based on the facts that genistin exerts inhibitory effects on the contractility of vascular smooth muscle,the present study was designed to characterize the effects of genistin on intestinal contractility and evaluate its potential clinical implication. Ex vivo [isolated jejunal segment (IJS) of rat], in vitro, and in vivo assays were used in the study. The results indicated that genistin (5-80 μmol/L) inhibited the contraction of IJS in a dose-dependent manner and inhibited the increased-contractility of IJS induced by acetylcholine (ACh), histamine, high Ca(2+), and erythromycin, respectively. The inhibitory effects of genistin were correlated with the stimulation of alpha adrenergic and beta adrenergic receptors since these inhibitory effects were significantly blocked in the presence of phentolamine and propranolol respectively. No further inhibitory effects of genistin were observed in the presence of verapamil or in Ca(2+)-free condition, indicating genistin-induced inhibitory effects are Ca(2+)-dependent. Genistin decreased myosin light chain kinase (MLCK) protein contents and MLCK mRNA expression in IJS, and inhibited both phosphorylation and Mg(2+)-ATPase activity of purified myosin, implicating that the decrease of MLCK contents and inhibition of MLCK activity are involved in the genistin-induced inhibitory effects. The study suggests the potential clinical implications of genistin in relieving intestinal hypercontractility.
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Affiliation(s)
- Yong-jian Xiong
- Department of Pharmacology, Dalian Medical University, Dalian, 116044, Liaoning, China
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16
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Meng J, Yu H, Ma J, Wang J, Banerjee S, Charboneau R, Barke RA, Roy S. Morphine induces bacterial translocation in mice by compromising intestinal barrier function in a TLR-dependent manner. PLoS One 2013; 8:e54040. [PMID: 23349783 PMCID: PMC3548814 DOI: 10.1371/journal.pone.0054040] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 12/07/2012] [Indexed: 01/08/2023] Open
Abstract
Opiates are among the most prescribed drugs for pain management. However, morphine use or abuse results in significant gut bacterial translocation and predisposes patients to serious infections with gut origin. The mechanism underlying this defect is still unknown. In this report, we investigated the mechanisms underlying compromised gut immune function and bacterial translocation following morphine treatment. We demonstrate significant bacterial translocation to mesenteric lymph node (MLN) and liver following morphine treatment in wild-type (WT) animals that was dramatically and significantly attenuated in Toll-like receptor (TLR2 and 4) knockout mice. We further observed significant disruption of tight junction protein organization only in the ileum but not in the colon of morphine treated WT animals. Inhibition of myosin light chain kinase (MLCK) blocked the effects of both morphine and TLR ligands, suggesting the role of MLCK in tight junction modulation by TLR. This study conclusively demonstrates that morphine induced gut epithelial barrier dysfunction and subsequent bacteria translocation are mediated by TLR signaling and thus TLRs can be exploited as potential therapeutic targets for alleviating infections and even sepsis in morphine-using or abusing populations.
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Affiliation(s)
- Jingjing Meng
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Haidong Yu
- Department of Surgery, Division of Infection, Inflammation, and Vascular Biology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Jing Ma
- Department of Surgery, Division of Infection, Inflammation, and Vascular Biology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Jinghua Wang
- Department of Surgery, Division of Infection, Inflammation, and Vascular Biology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Santanu Banerjee
- Department of Surgery, Division of Infection, Inflammation, and Vascular Biology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Rick Charboneau
- Department of Surgery, Veterans Affairs Medical Center, Minneapolis, Minnesota, United States of America
| | - Roderick A. Barke
- Department of Surgery, Veterans Affairs Medical Center, Minneapolis, Minnesota, United States of America
| | - Sabita Roy
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
- Department of Surgery, Division of Infection, Inflammation, and Vascular Biology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
- * E-mail:
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17
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Wang L, Jia C, Yu Z, Liu X, Kang L, Cong Y, Shan Y, Zhao Z, Ma B, Cong Y. Pennogenin tetraglycoside induces rat myometrial contraction and MLC20 phosphorylation via PLC-IP(3) and RhoA/Rho kinase signaling pathways. PLoS One 2012; 7:e51536. [PMID: 23251567 PMCID: PMC3520837 DOI: 10.1371/journal.pone.0051536] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 11/08/2012] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Total steroidal saponins extracted from the rhizome of Paris polyphylla Sm. var. yunnanensis (TSSPs) have been widely used in China for the treatment of abnormal uterine bleeding. We previously studied the main active constituents of TSSPs and their structure-activity relationships with respect to rat myometrial contractions. Tg (pennogenin tetraglycoside) was identified as one of the active ingredients in TSSPs able to induce rat myometrial contractions. However, the mechanisms underlying the pharmacological actions on uterine activity have not been described clearly. METHODS Here Tg was screened for effects on contractile activity in isolated uterine strips from estrogen-primed rats and on MLC20 phosphorylation and related signaling pathways in cultured rat myometrial cells as determined by Western blot. Intracellular calcium ([Ca(2+)](i)) was monitored under a confocal microscope using Fluo-4 AM-loaded myometrial cells. RESULTS Tg dose-dependently stimulated rat myometrial contractions as well as MLC20 phosphorylation in vitro, which could be completely suppressed by an inhibitor of myosin light chain kinase (MLCK). Use of Ca(2+) channel blockers and kinase inhibitors demonstrated that Tg-induced myometrial contractions are mediated by activation of the phospholipase C (PLC)-inositol triphosphate (IP3) signaling pathway, resulting in increased MLC20 phosphorylation. Furthermore, Y27632, a specific inhibitor of Rho kinase (ROK), notably suppressed Tg-stimulated myometrial contractions and decreased MLC20 phosphorylation. CONCLUSIONS These data provide evidence that rat myometrial contractility induced by Tg results from enhanced MLC20 phosphorylation, while both PLC-IP3 and RhoA/ROK signaling pathways mediate the process. These mechanisms may be responsible for the therapeutic effects of TSSPs on abnormal uterine bleeding.
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Affiliation(s)
- Limei Wang
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Chao Jia
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Zuyin Yu
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Xiaolan Liu
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Liping Kang
- Department of Biotechnology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Yue Cong
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Yajun Shan
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Zhenhu Zhao
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Baiping Ma
- Department of Biotechnology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Yuwen Cong
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
- * E-mail:
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Khapchaev AI, Samsonov MV, Kazakova OA, Vilitkevich EL, Sidorova MV, Az'muko AA, Molokoedov AS, Bespalova ZD, Shirinskiĭ VP. [Suppression of vascular endothelium hyperpermeability by cell-permeating peptide inhibitors of myosin light chain kinase]. Biofizika 2012; 57:764-770. [PMID: 23136768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Novel peptides originating from the peptide inhibitor of myosin light chain kinase, L-PIK (Arg-Lys-Lys-Tyr-Lys-Tyr-Arg-Arg-Lys), have been studied for ability to attenuate the thrombin-induced hyperpermeability of endothelial cell monolayer in culture. Peptides [NalphaMeArg1]-Lys-Lys-Tyr-Lys-Tyr-Arg-(D)Arg8-Lys and H-Arg(NO2)Lys-Lys-Tyr-Lys-Tyr-Arg-Arg-Lys-NH2 (designated PIK2 and PIK4, respectively) appeared to be the most effective inhibitors of endothelial cell monolayer hyperpermebility, and surpassed other known peptide inhibitors of myosin light chain kinase derived from original L-PIK. Our results validate PIK2 and PIK4 as the leading molecules for the development of novel drugs intended to counteract pathological hyperpermeability of vascular endothelium.
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19
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Park YM, Drazba JA, Vasanji A, Egelhoff T, Febbraio M, Silverstein RL. Oxidized LDL/CD36 interaction induces loss of cell polarity and inhibits macrophage locomotion. Mol Biol Cell 2012; 23:3057-68. [PMID: 22718904 PMCID: PMC3418302 DOI: 10.1091/mbc.e11-12-1051] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 04/30/2012] [Accepted: 06/13/2012] [Indexed: 02/06/2023] Open
Abstract
Cell polarization is essential for migration and the exploratory function of leukocytes. However, the mechanism by which cells maintain polarity or how cells revert to the immobilized state by gaining cellular symmetry is not clear. Previously we showed that interaction between oxidized low-density lipoprotein (oxLDL) and CD36 inhibits macrophage migration; in the current study we tested the hypothesis that oxLDL/CD36-induced inhibition of migration is the result of intracellular signals that regulate cell polarity. Live cell imaging of macrophages showed that oxLDL actuated retraction of macrophage front end lamellipodia and induced loss of cell polarity. Cd36 null and macrophages null for Vav, a guanine nucleotide exchange factor (GEF), did not show this effect. These findings were caused by Rac-mediated inhibition of nonmuscle myosin II, a cell polarity determinant. OxLDL induced dephosphorylation of myosin regulatory light chain (MRLC) by increasing the activity of Rac. Six-thioguanine triphosphate (6-thio-GTP), which inhibits Vav-mediated activation of Rac, abrogated the effect of oxLDL. Activation of the Vav-Rac-myosin II pathway by oxidant stress may induce trapping of macrophages at sites of chronic inflammation such as atherosclerotic plaque.
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Affiliation(s)
- Young Mi Park
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195
| | - Judith A. Drazba
- Imaging Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Amit Vasanji
- Biomedical Imaging and Analysis Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Thomas Egelhoff
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195
| | - Maria Febbraio
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195
| | - Roy L. Silverstein
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195
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20
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Stroka KM, Aranda-Espinoza H. Endothelial cell substrate stiffness influences neutrophil transmigration via myosin light chain kinase-dependent cell contraction. Blood 2011; 118:1632-40. [PMID: 21652678 PMCID: PMC3156049 DOI: 10.1182/blood-2010-11-321125] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Accepted: 05/19/2011] [Indexed: 11/20/2022] Open
Abstract
A vast amount of work has been dedicated to the effects of shear flow and cytokines on leukocyte transmigration. However, no studies have explored the effects of substrate stiffness on transmigration. Here, we investigated important aspects of endothelial cell contraction-mediated neutrophil transmigration using an in vitro model of the vascular endothelium. We modeled blood vessels of varying mechanical properties using fibronectin-coated polyacrylamide gels of varying physiologic stiffness, plated with human umbilical vein endothelial cell (HUVEC) monolayers, which were activated with tumor necrosis factor-α. Interestingly, neutrophil transmigration increased with increasing substrate stiffness below the endothelium. HUVEC intercellular adhesion molecule-1 expression, stiffness, cytoskeletal arrangement, morphology, and cell-substrate adhesion could not account for the dependence of transmigration on HUVEC substrate stiffness. We also explored the role of cell contraction and observed that large holes formed in endothelium on stiff substrates several minutes after neutrophil transmigration reached a maximum. Further, suppression of contraction through inhibition of myosin light chain kinase normalized the effects of substrate stiffness by reducing transmigration and eliminating hole formation in HUVECs on stiff substrates. These results provide strong evidence that neutrophil transmigration is regulated by myosin light chain kinase-mediated endothelial cell contraction and that this event depends on subendothelial cell matrix stiffness.
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Affiliation(s)
- Kimberly M Stroka
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, USA
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21
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Mirzapoiazova T, Moitra J, Moreno-Vinasco L, Sammani S, Turner JR, Chiang ET, Evenoski C, Wang T, Singleton PA, Huang Y, Lussier YA, Watterson DM, Dudek SM, Garcia JGN. Non-muscle myosin light chain kinase isoform is a viable molecular target in acute inflammatory lung injury. Am J Respir Cell Mol Biol 2011; 44:40-52. [PMID: 20139351 PMCID: PMC3028257 DOI: 10.1165/rcmb.2009-0197oc] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2009] [Accepted: 11/24/2009] [Indexed: 01/03/2023] Open
Abstract
Acute lung injury (ALI) and mechanical ventilator-induced lung injury (VILI), major causes of acute respiratory failure with elevated morbidity and mortality, are characterized by significant pulmonary inflammation and alveolar/vascular barrier dysfunction. Previous studies highlighted the role of the non-muscle myosin light chain kinase isoform (nmMLCK) as an essential element of the inflammatory response, with variants in the MYLK gene that contribute to ALI susceptibility. To define nmMLCK involvement further in acute inflammatory syndromes, we used two murine models of inflammatory lung injury, induced by either an intratracheal administration of lipopolysaccharide (LPS model) or mechanical ventilation with increased tidal volumes (the VILI model). Intravenous delivery of the membrane-permeant MLC kinase peptide inhibitor, PIK, produced a dose-dependent attenuation of both LPS-induced lung inflammation and VILI (~50% reductions in alveolar/vascular permeability and leukocyte influx). Intravenous injections of nmMLCK silencing RNA, either directly or as cargo within angiotensin-converting enzyme (ACE) antibody-conjugated liposomes (to target the pulmonary vasculature selectively), decreased nmMLCK lung expression (∼70% reduction) and significantly attenuated LPS-induced and VILI-induced lung inflammation (∼40% reduction in bronchoalveolar lavage protein). Compared with wild-type mice, nmMLCK knockout mice were significantly protected from VILI, with significant reductions in VILI-induced gene expression in biological pathways such as nrf2-mediated oxidative stress, coagulation, p53-signaling, leukocyte extravasation, and IL-6-signaling. These studies validate nmMLCK as an attractive target for ameliorating the adverse effects of dysregulated lung inflammation.
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Affiliation(s)
- Tamara Mirzapoiazova
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Jaideep Moitra
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Liliana Moreno-Vinasco
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Saad Sammani
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Jerry R. Turner
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Eddie T. Chiang
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Carrie Evenoski
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Ting Wang
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Patrick A. Singleton
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Yong Huang
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Yves A. Lussier
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - D. Martin Watterson
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Steven M. Dudek
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
| | - Joe G. N. Garcia
- Department of Medicine, University of Chicago; Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago; Department of Pathology; Section of Genetic Medicine, University of Chicago; Northwestern Medical School; and Institute for Personalized and Respiratory Medicine, University of Illinois at Chicago, Chicago Illinois
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22
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Marchenko AV, Stepanova EO, Sekridova AV, Sidorova MV, Bushuev VN, Bespalova ZD, Shirinskiĭ VP. [Novel peptide inhibitors of the myosin light chain kinase suppress hyperpermeability of vascular endothelium]. Biofizika 2010; 55:1008-1013. [PMID: 21268344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The ability of novel cell-permeating peptide molecules derived from the peptide inhibitor of the myosin light chain kinase (MLCK) L-PIK (Arg-Lys-Lys-Tyr-Lys-Tyr-Arg-Arg-Lys) to inhibit this kinase in vitro and attenuate the thrombin-induced hyperpermeability of endothelial cell monolayer in culture has been studied. It was found that the compounds [NalphaMeArg1]-L-PIK and [Cit1]-L-PIK possess the inhibitory activity towards MLCK comparable to that of L-PIK and the ability to suppress the hyperpermeability of endothelium, whereas other modifications of L-PIK were less effective. Thus, among de novo synthesized peptides, [NalphaMeArg1]-L-PIK and [Cit1]-L-PIK demonstrate the inhibitory properties of the original peptide L-PIK and additionally surpass it by stability in blood plasma. These peptides may be used in the design of novel antiedemic drugs.
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23
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Llewellyn GN, Hogue IB, Grover JR, Ono A. Nucleocapsid promotes localization of HIV-1 gag to uropods that participate in virological synapses between T cells. PLoS Pathog 2010; 6:e1001167. [PMID: 21060818 PMCID: PMC2965768 DOI: 10.1371/journal.ppat.1001167] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 09/28/2010] [Indexed: 12/20/2022] Open
Abstract
T cells adopt a polarized morphology in lymphoid organs, where cell-to-cell transmission of HIV-1 is likely frequent. However, despite the importance of understanding virus spread in vivo, little is known about the HIV-1 life cycle, particularly its late phase, in polarized T cells. Polarized T cells form two ends, the leading edge at the front and a protrusion called a uropod at the rear. Using multiple uropod markers, we observed that HIV-1 Gag localizes to the uropod in polarized T cells. Infected T cells formed contacts with uninfected target T cells preferentially via HIV-1 Gag-containing uropods compared to leading edges that lack plasma-membrane-associated Gag. Cell contacts enriched in Gag and CD4, which define the virological synapse (VS), are also enriched in uropod markers. These results indicate that Gag-laden uropods participate in the formation and/or structure of the VS, which likely plays a key role in cell-to-cell transmission of HIV-1. Consistent with this notion, a myosin light chain kinase inhibitor, which disrupts uropods, reduced virus particle transfer from infected T cells to target T cells. Mechanistically, we observed that Gag copatches with antibody-crosslinked uropod markers even in non-polarized cells, suggesting an association of Gag with uropod-specific microdomains that carry Gag to uropods. Finally, we determined that localization of Gag to the uropod depends on higher-order clustering driven by its NC domain. Taken together, these results support a model in which NC-dependent Gag accumulation to uropods establishes a preformed platform that later constitutes T-cell-T-cell contacts at which HIV-1 virus transfer occurs. CD4+ T cells are natural targets of HIV-1. Efficient spread of HIV-1 from infected T cells to uninfected T cells is thought to occur via cell-cell contact structures. One of these structures is a virological synapse where both viral and cellular proteins have been shown to localize specifically. However, the steps leading to the formation of a virological synapse remain unknown. It has been observed that T cells adopt a polarized morphology in lymph nodes where cell-to-cell virus transmission is likely to occur frequently. In this study, we show that in polarized T cells, the primary viral structural protein Gag accumulates to the plasma membrane of a rear end structure called a uropod. We found that Gag multimerization, driven by its nucleocapsid domain, is essential for Gag localization to uropods and that HIV-1-laden uropods mediate contact with target cells and can become part of the virological synapse. Our findings elucidated a series of molecular events leading to formation of HIV-1-transferring cell contacts and support a model in which the uropod acts as a preformed platform that constitutes a virological synapse after cell-cell contact.
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Affiliation(s)
- G. Nicholas Llewellyn
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Ian B. Hogue
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jonathan R. Grover
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Akira Ono
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
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24
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Sekridova AV, Sidorova MV, Az'muko AA, Molokoedov AS, Bushuev VN, Marchenko AV, Shcherbakova OV, Shirinskiĭ VP, Bespalova ZD. [Peptide inhibitors of myosin light chain kinase. Development of peptidase resistant analogues]. Bioorg Khim 2010; 36:498-504. [PMID: 20823918 DOI: 10.1134/s1068162010040047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Myosin light chain kinase (MLCK) is the key regulator of various forms of cell motility including endothelial and epithelial permeability in particular. One of the potential MLCK inhibitors to be used in humans is a membrane permeable peptide H-RKKYKYRRK-NH2 (L-PIK). In present work we used solid phase peptide synthesis and Fmoc-technology to produce five modifications of L-PIK. Based on (1)H NMR analysis revealed that these peptides demonstrated improved resistance to degradation in blood plasma. One of de novo synthesized peptides, L-[MeArg(1)]PIK inhibited MLCK activity in vitro with the same efficiency as L-PIK whereas other modified peptides showed reduced inhibitory activity. D-amino acid analog of PIK was the least active inhibitor. Thus, we have demonstrated the possibility to produce an effective MLCK peptide inhibitor with increased resistance to biodegradation that is suitable for further pharmacological development.
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25
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Marchenko AV, Sidorova MV, Sekridova AV, Bushuev VN, Lakomkin VL, Orlova TR, Stepanova OV, Kapel'ko VI, Watterson DM, Van Eldik LJ, Bespalova ZD, Shirinskiĭ VP. [Penetrating peptide inhibitor of the myosin light chain kinase suppresses hyperpermeability of vascular endothelium]. Ross Fiziol Zh Im I M Sechenova 2009; 95:507-515. [PMID: 19569527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nonapeptide H-Arg-Lys-Lys-Tyr-Lys-Tyr-Arg-Arg-Lys-NH2 corresponding to a modified sequence of autoinhibitory region of myosin light chain kinase (MLCK) was synthesized from L-amino acids and from D-amino acids. Using nuclear magnetic resonance spectroscopy it has been demonstrated that D-peptide is significantly more stable in human blood plasma than its L-enantiomer. D-peptide accumulated in cultured human umbilical vein endothelial cells suppressed development of hyperpermeability in endothelial monolayer induced by thrombin addition. Following intravenous administration D-peptide decreased the extent of lung oedema in rats induced by infusion of oleic acid in bloodstream. Thus, the peptide molecules based on an autoinhibitory peptide of MLCK may serve as a prototype for development of a novel antioedematous drugs that directly affect the MLCK-dependent motile processes in vascular endothelium.
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26
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Bai JW, Deng WW, Zhang J, Xu SM, Zhang DX. [Protective effect of myosin light-chain kinase inhibitor on acute lung injury]. Zhongguo Wei Zhong Bing Ji Jiu Yi Xue 2009; 21:215-218. [PMID: 19374788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
OBJECTIVE To investigate the influence of inhibitor of myosin light-chain kinase (MLCK) on the human pulmonary arterial endothelial cell (HPAEC) challenged with lipopolysaccharide (LPS) and LPS induced of acute lung injury (ALI) in mice. METHODS HPAECs were cultured in ECM medium and its passages 4-6 were used. After treatment with inhibitor of MLCK (ML-7) for 60 minutes, the HPAECs were incubated in LPS for another 60 minutes, and then cell viability was measured by the methyl thiazolyl tetrazolium (MTT) assay. Immunofluorescence microscope was used to detect phosphorylated-MLCK (p-MLCK) immunoreactive cells. Twenty female BALB/c mice were randomly divided into two groups. The mice of LPS group were exposed to LPS (1 microg/g) through nasal instillation, and the mice of ML-7 group were pretreated with ML-7 before intranasal instillation of LPS. Wet/dry weight (W/D) ratio of lung, bronchoalveolar lavage fluid (BALF) protein content, myeloperoxidase (MPO) activity and histopathological changes of lung tissue were observed. Immunohistochemistry assays were used to determine the status of MLCK and CD11b immunoreactive cells in lung tissue, and expression of MLCK mRNA in lung tissue was assessed by reverse transcription-polymerase chain reaction (RT-PCR). Expression of MLCK protein in lungs was assayed by Western blotting. RESULTS Compared with LPS group, increased absorbance (A) value of HPAEC was found in ML-7 group (P<0.01). Immunoreactive cells of p-MLCK were more reduced in the ML-7 group (P<0.05), and W/D ratio of lung, MPO activity and BALF protein content of lung tissue were decreased in ML-7 group (P<0.05 or P<0.01). Histological examination showed that an extensive lung inflammation was seen in mice of LPS group, with an accumulation of a large number of neutrophils, marked pulmonary edema and hemorrhage, but the inflammation and parenchymal hemorrhage was significantly alleviated in ML-7 group. Both MLCK immunoreactive cells located in endothelium and CD11b in infiltrated inflammatory cells were decreased in ML-7 group compared with those in LPS group. Compared with LPS group, MLCK mRNA and protein expressions (A) in ML-7 group were significantly decreased (both P<0.05). CONCLUSION ML-7, an MLCK inhibitor, enhances activity of HPAEC induced by LPS and reduces expression of p-MLCK. It also reduces the LPS-induced infiltration of neutrophils in lung tissues, pulmonary edema and expression of MLCK and CD11b protein and MLCK mRNA in lung tissues, demonstrating that inhibition of activation of MLCK, leading to an abatement of phosphorylation of myosin light chain or MLCK, resulting in stabilization of vascular barrier function. The results suggest that MLCK has a crucial role in the pathogenesis of ALI.
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Affiliation(s)
- Jian-wen Bai
- Department of Emergency and Intensive Critical Medicine, Dongfang Hospital Affiliated to Tongji University, Shanghai 200120, China
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27
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Park JY, Shin HK, Lee YJ, Choi YW, Bae SS, Kim CD. The mechanism of vasorelaxation induced by Schisandra chinensis extract in rat thoracic aorta. J Ethnopharmacol 2009; 121:69-73. [PMID: 18983904 DOI: 10.1016/j.jep.2008.09.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2008] [Revised: 09/12/2008] [Accepted: 09/29/2008] [Indexed: 05/27/2023]
Abstract
AIM OF THE STUDY Schisandra chinensis (SC) is a known medical herb for the treatment of cardiovascular symptoms associated with menopausal symptoms in Korea. However, the pharmacological action mechanisms involved have not been well studied. This study was aimed to investigate the vascular effects of SC in rat thoracic aorta. MATERIALS AND METHODS We isolated the hexane, chloroform, and methanol extracts from SC and evaluated their vasodilatory effects in the rat thoracic aorta. RESULTS Hexane extracts of SC (SCHE, 5 x 10(-5) to 10(-3) g/L) caused a concentration-dependent relaxation in both endothelium-intact and -denuded aortas. The relaxant effect of SCHE on the endothelium-intact aorta was more prominent than on the endothelium-denuded aorta. The former was significantly attenuated by L-NAME, a nitric oxide synthase inhibitor, and ODQ, a soluble guanyl cyclase inhibitor, but not by tetraethylammonium, a nonselective blocker of K(+) channels, and indomethacin, a cyclooxygenase inhibitor. Furthermore, SCHE caused nitrite production as well as eNOS activation in aortic segments, suggesting implication of NO signal pathway in SCHE-induced relaxation. In endothelium-denuded aorta, SCHE-induced vasorelaxation was also attenuated by calyculin A, an inhibitor of myosin light chain (MLC) phosphatase, but not by ML-9, a MLC kinase inhibitor, suggestive of implication of MLC phosphatase activation. Phenylephrine-enhanced MLC phosphorylation ratio was significantly attenuated by SCHE, which was recovered to the control level by pretreatment with calyculin A. CONCLUSIONS Taken collectively, these findings suggest that the vascular relaxation evoked by SCHE was mediated by not only endothelium dependent NO pathway but also direct effect on vascular smooth muscle cell via dephosphorylation of MLC.
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MESH Headings
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/physiology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/physiology
- Fruit/chemistry
- In Vitro Techniques
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Myosin-Light-Chain Kinase/antagonists & inhibitors
- Myosin-Light-Chain Kinase/metabolism
- Myosin-Light-Chain Phosphatase/antagonists & inhibitors
- Myosin-Light-Chain Phosphatase/metabolism
- Nitric Oxide/physiology
- Phosphorylation
- Plant Extracts/chemistry
- Plant Extracts/isolation & purification
- Plant Extracts/pharmacology
- Rats
- Rats, Sprague-Dawley
- Schisandra/chemistry
- Vasodilation/drug effects
- Vasodilation/physiology
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Affiliation(s)
- Ji Young Park
- Department of Pharmacology, College of Medicine, Pusan National University, Busan 602-739, Republic of Korea
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28
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Thoenes L, Günther M. Novel approaches in anti-angiogenic treatment targeting endothelial F-actin: a new anti-angiogenic strategy? Curr Opin Mol Ther 2008; 10:579-590. [PMID: 19051136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
As a functional blood supply is crucial for growth of solid tumors, the development of anticancer agents to inhibit the formation of new tumor blood vessels is an area of extensive research. Endothelial cell motility driven by the dynamics of the cytoskeleton is a key feature of angiogenesis. Agents that preferentially target endothelial tubulin are well established, and inhibition of the endothelial actin dynamics appears to be another promising anti-angiogenic strategy. Remodeling of the actin cytoskeleton is regulated by several pathways involving a large number of signaling proteins. Therefore, therapeutic strategies for the modulation of actin dynamics include agents that target the actin cytoskeleton directly, as well as inhibitors of actin binding proteins and regulators in upstream pathways. This review provides an overview of the regulation of the actin cytoskeleton and proteins that could potentially be targeted by therapeutic agents. In addition, an outline of promising agents, which includes recombinant proteins, endogenous effectors and treatment regimes that exert anti-angiogenic effects partly mediated by affecting endothelial actin dynamics is provided.
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Affiliation(s)
- Lilja Thoenes
- Ludwig-Maximilian-Universität, Pharmaceutical Biology-Biotechnology, Butenandtstrasse 5-13, D-81377 Munich, Germany
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29
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Collin O, Na S, Chowdhury F, Hong M, Shin ME, Wang F, Wang N. Self-organized podosomes are dynamic mechanosensors. Curr Biol 2008; 18:1288-94. [PMID: 18760605 DOI: 10.1016/j.cub.2008.07.046] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 07/03/2008] [Accepted: 07/07/2008] [Indexed: 01/16/2023]
Abstract
Podosomes are self-organized, dynamic, actin-containing structures that adhere to the extracellular matrix via integrins [1-5]. Yet, it is not clear what regulates podosome dynamics and whether podosomes can function as direct mechanosensors, like focal adhesions [6-9]. We show here that myosin-II proteins form circular structures outside and at the podosome actin ring to regulate podosome dynamics. Inhibiting myosin-II-dependent tension dissipated podosome actin rings before dissipating the myosin-ring structure. As podosome rings changed size or shape, tractions underneath the podosomes were exerted onto the substrate and were abolished when myosin-light-chain activity was inhibited. The magnitudes of tractions were comparable to those generated underneath focal adhesions, and they increased with substrate stiffness. The dynamics of podosomes and of focal adhesions were different. Torsional tractions underneath the podosome rings were generated with rotations of podosome rings in a nonmotile, nonrotating cell, suggesting a unique feature of these circular structures. Stresses applied via integrins at the apical surface directly displaced podosomes near the basal surface. Stress-induced podosome displacements increased nonlinearly with applied stresses. Our results suggest that podosomes are dynamic mechanosensors in which interactions of myosin tension and actin dynamics are crucial for regulating these self-organized structures in living cells.
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Affiliation(s)
- Olivier Collin
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Feighery LM, Cochrane SW, Quinn T, Baird AW, O'Toole D, Owens SE, O'Donoghue D, Mrsny RJ, Brayden DJ. Myosin light chain kinase inhibition: correction of increased intestinal epithelial permeability in vitro. Pharm Res 2008; 25:1377-86. [PMID: 18163202 DOI: 10.1007/s11095-007-9527-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Accepted: 12/10/2007] [Indexed: 01/12/2023]
Abstract
PURPOSE To examine whether myosin light chain kinase (MLCK) inhibitors can reduce intestinal epithelial permeability increases in vitro. MATERIALS AND METHODS Isolated rat, mouse and human colonic tissue mucosae and Caco-2 monolayers were exposed to cytochalasin D (cD) and sodium caprate (C10), in the absence and presence of the MLCK inhibitors, ML-9 and D PIK. Transepithelial electrical resistance (TEER) and Papp of [14C]-mannitol or FITC-dextran 4000 (FD-4) were measured. Western blots were used to measure MLC phosphorylation. RESULTS Increases in Papp of [14C]-mannitol and decreases in TEER were induced by tight junction openers. These changes were attenuated by ML-9. D-PIK offset the FD-4 Papp increase induced by C10 in Caco-2 only, while ML-9 and PIK inhibited MLC directly, cD induced constriction of peri-junctional actin in Caco-2 monolayers, but this was prevented by ML-9. Although mannitol fluxes across colonic mucosae from dextran-sulphate (DSS)-treated mice were higher than control, they were not ameliorated by either ML-9 or PIK in vitro. CONCLUSIONS ML-9 inhibits paracellular permeability increases in several intestinal epithelial models. D-PIK reduced stimulated paracellular fluxes in Caco-2 monolayers, but not in tissue. Pre-established increases were not modified by two MLCK inhibitors in a mouse model of IBD.
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Affiliation(s)
- Linda M Feighery
- School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
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Zhou X, Liu Y, You J, Zhang H, Zhang X, Ye L. Myosin light-chain kinase contributes to the proliferation and migration of breast cancer cells through cross-talk with activated ERK1/2. Cancer Lett 2008; 270:312-27. [PMID: 18710790 DOI: 10.1016/j.canlet.2008.05.028] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 04/24/2008] [Accepted: 05/15/2008] [Indexed: 11/17/2022]
Abstract
Myosin light-chain kinase (MLCK) plays a crucial role in the cell migration and tumor metastasis. Herein, we investigated the signaling pathways involved in MLCK using ML-7, a specific inhibitor of MLCK, in breast cancer cell proliferation and migration. Our data showed that reduction of MLCK in breast cancer cells mediated by 20 microM ML-7 was able to depress the cell proliferation and migration using two parallel cell lines (MCF-7 and LM-MCF/MDA-MB-231) with different metastatic abilities through reciprocal cross-talk with activated ERK1/2, in which both phosphorylated myosin light chain (p-MLC) and cascades of beta-catenin, cyclin D1, survivin, and c-Myc serve as essential downstream effectors.
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Affiliation(s)
- Xiaolei Zhou
- Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071, PR China
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Farahbakhsh NA, Narins PM. Slow motility in hair cells of the frog amphibian papilla: myosin light chain-mediated shape change. Hear Res 2008; 241:7-17. [PMID: 18534795 PMCID: PMC2516351 DOI: 10.1016/j.heares.2008.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Revised: 04/10/2008] [Accepted: 04/14/2008] [Indexed: 12/01/2022]
Abstract
Using video, fluorescence and confocal microscopy, quantitative analysis and modeling, we investigated intracellular processes mediating the calcium/calmodulin (Ca(2+)/CaM)-dependent slow motility in hair cells dissociated from the rostral region of amphibian papilla, one of the two auditory organs in frogs. The time course of shape changes in these hair cells during the period of pretreatment with several specific inhibitors, as well as their response to the calcium ionophore, ionomycin, were recorded and compared. These cells respond to ionomycin with a tri-phasic shape change: an initial phase of iso-volumetric length decrease; a period of concurrent shortening and swelling; and the final phase of increase in both length and volume. We found that both the myosin light chain kinase inhibitor, ML-7, and antagonists of the multifunctional Ca(2+)/CaM-dependent kinases, KN-62 and KN-93, inhibit the iso-volumetric shortening phase of the response to ionomycin. The type 1 protein phosphatase inhibitors, calyculin A and okadaic acid induce minor shortening on their own, but do not significantly alter phase 1 response. However, they appear to counter effects of the inhibitors of Ca(2+)/CaM-dependent kinases. We hypothesize that an active actomyosin-based process mediates the iso-volumetric shortening in the frog rostral amphibian papillar hair cells.
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Affiliation(s)
- Nasser A Farahbakhsh
- Department of Physiological Science, 621 Charles E. Young Drive S., University of California, Los Angeles, CA 90095-1606, USA.
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Ewald AJ, Brenot A, Duong M, Chan BS, Werb Z. Collective epithelial migration and cell rearrangements drive mammary branching morphogenesis. Dev Cell 2008; 14:570-81. [PMID: 18410732 DOI: 10.1016/j.devcel.2008.03.003] [Citation(s) in RCA: 471] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2007] [Revised: 10/24/2007] [Accepted: 03/04/2008] [Indexed: 11/18/2022]
Abstract
Epithelial organs are built through the movement of groups of interconnected cells. We observed cells in elongating mammary ducts reorganize into a multilayered epithelium, migrate collectively, and rearrange dynamically, all without forming leading cellular extensions. Duct initiation required proliferation, Rac, and myosin light-chain kinase, whereas repolarization to a bilayer depended on Rho kinase. We observed that branching morphogenesis results from the active motility of both luminal and myoepithelial cells. Luminal epithelial cells advanced collectively, whereas myoepithelial cells appeared to restrain elongating ducts. Significantly, we observed that normal epithelium and neoplastic hyperplasias are organized similarly, suggesting common mechanisms of epithelial growth.
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Affiliation(s)
- Andrew J Ewald
- Department of Anatomy and Program in Cell Biology, University of California, San Francisco, San Francisco, CA 94143, USA.
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Abstract
Our previous research showed that Rho kinase took part in the regulation of vascular hyporeactivity after shock. The objective of the present study was to investigate its mechanism. With isolated superior mesenteric artery (SMA) from hemorrhagic shock rats, we studied the relationship of Rho kinase regulating vascular reactivity to calcium sensitivity and myosin light chain phosphatase (MLCP) and myosin light chain kinase (MLCK). The vascular reactivity and calcium sensitivity of SMA were observed by measuring the contraction initiated by accumulative norepinephrine (NE) and calcium under depolarizing condition (120 mM K(+)) with an isolated organ perfusion system. Hypoxia-treated vascular smooth muscle cells (VSMCs) were used to study the effects of Rho kinase on the activity of MLCP and MLCK and the phosphorylation of 20-kDa myosin light chain (MLC(20)). Myosin light chain (20 kDa) phosphorylation of VSMC in mesenteric artery was detected by immunoprecipitation and Western blotting. The activity of MLCP and MLCK was assayed by enzymatic catalysis. The contractile response of VSMC was measured by the ratio of accumulative infiltration of fluorescent isothiocyanate-conjugated bovine serum albumin through transwell. The results indicated that the vascular reactivity and calcium sensitivity of SMA to NE and calcium following hemorrhagic shock and the contractile response of VSMC to NE following hypoxia were significantly decreased. Angiotensin II (Ang-II), the Rho kinase stimulator, significantly improved hypoxia or hemorrhagic shock-induced decrease of vascular reactivity and calcium sensitivity. These effects of Ang-II on vascular reactivity were abolished by Y-27632, the specific Rho kinase inhibitor. Calyculin A, the MLCP inhibitor, further enhanced Ang-II-induced increase of calcium sensitivity, but ML-9, the MLCK inhibitor, had no effect. Further studies showed Ang-II reversed the hypoxia-induced increase of MLCP activity and increased the hypoxia-induced decrease of MLC(20) phosphorylation in VSMC. It was suggested that Rho kinase played an important role in the regulation of vascular reactivity after hemorrhagic shock. The mechanisms may be related to its calcium sensitivity regulation. Rho kinase up-regulates calcium sensitivity of VSMC possibly through inhibiting the activity of MLCP and increasing the phosphorylation of MLC(20).
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Affiliation(s)
- Tao Li
- State Key Laboratory of Trauma, Burns and Combined Injury, The 2nd Department of Research Institute of Surgery, Daping Hospital, The Third Military Medical University, Chongqing, PR China.
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Raizman JE, Komljenovic J, Chang R, Deng C, Bedosky KM, Rattan SG, Cunnington RH, Freed DH, Dixon IMC. The participation of the Na+-Ca2+ exchanger in primary cardiac myofibroblast migration, contraction, and proliferation. J Cell Physiol 2008; 213:540-51. [PMID: 17541957 DOI: 10.1002/jcp.21134] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Cardiac ventricular myofibroblast motility, proliferation, and contraction contribute to post-myocardial infarct wound healing, infarct scar formation, and remodeling of the ventricle remote to the site of infarction. The Na+-Ca2+ exchanger (NCX1) is involved in altered calcium handling in cardiac myocytes during cardiac remodeling associated with heart failure, however, its role in cardiac myofibroblast cell function is unexplored. In this study we investigated the involvement of NCX1 as well as the role of non-selective-cation channels (NSCC) in cardiac myofibroblast cell function in vitro. Immunofluorescence and Western blots revealed that P1 cells upregulate alpha-smooth muscle actin (alphaSMA) and embryonic smooth muscle myosin heavy chain (SMemb) expression. NCX1 mRNA and proteins as well as Ca(v)1.2a protein are also expressed in P1 myofibroblasts. Myofibroblast motility in the presence of 50 ng/ml PDGF-BB was blocked with AG1296. Myofibroblast motility, contraction, and proliferation were sensitive to KB-R7943, a specific NCX1 reverse-mode inhibitor. In contrast, only proliferation and contraction, but not motility were sensitive to nifedipine, while gadolinium (NSCC blocker) was only associated with decreased motility. ML-7 treatment was associated with inhibition of the chemotactic response and contraction. Thus cardiac myofibroblast chemotaxis, contraction, and proliferation were sensitive to different pharmacologic treatments suggesting that regulation of transplasmalemmal calcium movements may be important in growth factor receptor-mediated processes. NCX1 may represent an important moiety in suppression of myofibroblast functions.
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Affiliation(s)
- Joshua E Raizman
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre and Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada
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Seguchi O, Takashima S, Yamazaki S, Asakura M, Asano Y, Shintani Y, Wakeno M, Minamino T, Kondo H, Furukawa H, Nakamaru K, Naito A, Takahashi T, Ohtsuka T, Kawakami K, Isomura T, Kitamura S, Tomoike H, Mochizuki N, Kitakaze M. A cardiac myosin light chain kinase regulates sarcomere assembly in the vertebrate heart. J Clin Invest 2007; 117:2812-24. [PMID: 17885681 PMCID: PMC1978424 DOI: 10.1172/jci30804] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Accepted: 06/26/2007] [Indexed: 02/04/2023] Open
Abstract
Marked sarcomere disorganization is a well-documented characteristic of cardiomyocytes in the failing human myocardium. Myosin regulatory light chain 2, ventricular/cardiac muscle isoform (MLC2v), which is involved in the development of human cardiomyopathy, is an important structural protein that affects physiologic cardiac sarcomere formation and heart development. Integrated cDNA expression analysis of failing human myocardia uncovered a novel protein kinase, cardiac-specific myosin light chain kinase (cardiac-MLCK), which acts on MLC2v. Expression levels of cardiac-MLCK were well correlated with the pulmonary arterial pressure of patients with heart failure. In cultured cardiomyocytes, knockdown of cardiac-MLCK by specific siRNAs decreased MLC2v phosphorylation and impaired epinephrine-induced activation of sarcomere reassembly. To further clarify the physiologic roles of cardiac-MLCK in vivo, we cloned the zebrafish ortholog z-cardiac-MLCK. Knockdown of z-cardiac-MLCK expression using morpholino antisense oligonucleotides resulted in dilated cardiac ventricles and immature sarcomere structures. These results suggest a significant role for cardiac-MLCK in cardiogenesis.
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Affiliation(s)
- Osamu Seguchi
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Seiji Takashima
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Satoru Yamazaki
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Masanori Asakura
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Yoshihiro Asano
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Yasunori Shintani
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Masakatsu Wakeno
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Tetsuo Minamino
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Hiroya Kondo
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Hidehiko Furukawa
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Kenji Nakamaru
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Asuka Naito
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Tomoko Takahashi
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Toshiaki Ohtsuka
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Koichi Kawakami
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Tadashi Isomura
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Soichiro Kitamura
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Hitonobu Tomoike
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Naoki Mochizuki
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
| | - Masafumi Kitakaze
- Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
Department of Cardiovascular Medicine and
Health Care Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Core Technology Research Laboratories, Sankyo Co. Ltd., Shinagawa, Tokyo, Japan.
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Hayama Heart Center, Hayama, Kanagawa, Japan
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Abstract
BACKGROUND AND AIMS Intact protein absorption is thought to be a causative factor in several intestinal diseases, such as food allergy, celiac disease and inflammatory bowel disease. However, the mechanism remains unclear. The aim of this study was to characterize a novel signal transduction pathway via which heat stress compromises intestinal epithelial barrier function. METHODS Heat stress was carried out by exposing confluent human intestinal epithelial cell line T84 cell monolayers to designated temperatures (37-43 degrees C) for 1 h. Transepithelial electric resistance (TER) and permeability to horseradish peroxidase (HRP, molecular weight = 44 000) were used as indicators to assess the intestinal epithelial barrier function. Phosphorylated myosin light chain (MLC), MLC kinase (MLCK) and protein kinase C (PKC) protein of the T84 cells were evaluated in order to identify the signal transduction pathway in the course of heat stress-induced intestinal epithelial barrier dysfunctions. RESULTS The results showed that exposure to heat stress significantly increased intact protein transport across the intestinal epithelial monolayer; the amount of phospho-PKC, phospho-MLCK and phospho-MLC proteins in T84 cells decreased significantly at 41 degrees C and 43 degrees C although they increased at 39 degrees C. The heat stress-induced T84 monolayer barrier dysfunction was inhibited by pretreatment with PKC inhibitor, MLCK inhibitor, or HSP70. CONCLUSION Heat stress can induce intestinal epithelial barrier dysfunction via the PKC and MLC signal transduction pathway.
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Affiliation(s)
- Ping-Chang Yang
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada.
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Fabian L, Forer A. Possible roles of actin and myosin during anaphase chromosome movements in locust spermatocytes. Protoplasma 2007; 231:201-213. [PMID: 17922265 DOI: 10.1007/s00709-007-0262-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Accepted: 12/20/2006] [Indexed: 05/25/2023]
Abstract
We tested whether the mechanisms of chromosome movement during anaphase in locust (Locusta migratoria L.) spermatocytes might be similar to those described for crane-fly spermatocytes. Actin and myosin have been implicated in anaphase chromosome movements in crane-fly spermatocytes, as indicated by the effects of inhibitors and by the localisations of actin and myosin in spindles. In this study, we tested whether locust spermatocyte spindles also utilise actin and myosin, and whether actin is involved in microtubule flux. Living locust spermatocytes were treated with inhibitors of actin (latrunculin B and cytochalasin D), myosin (BDM), or myosin phosphorylation (Y-27632 and ML-7). We added drugs (individually) during anaphase. Actin inhibitors alter anaphase: chromosomes either completely stop moving, slow, or sometimes accelerate. The myosin inhibitor, BDM, also alters anaphase: in most cases, the chromosomes drastically slow or stop. ML-7, an inhibitor of MLCK, causes chromosomes to stop, slow, or sometimes accelerate, similar to actin inhibitors. Y-27632, an inhibitor of Rho-kinase, drastically slows or stops anaphase chromosome movements. The effects of the drugs on anaphase movement are reversible: most of the half-bivalents resumed movement at normal speed after these drugs were washed out. Actin and myosin were present in the spindles in locations consistent with their possible involvement in force production. Microtubule flux along kinetochore fibres is an actin-dependent process, since LatB completely removes or drastically reduces the gap in microtubule acetylation at the kinetochore. These results suggest that actin and myosin are involved in anaphase chromosome movements in locust spermatocytes.
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Brunsden AM, Brookes SJH, Bardhan KD, Grundy D. Mechanisms underlying mechanosensitivity of mesenteric afferent fibers to vascular flow. Am J Physiol Gastrointest Liver Physiol 2007; 293:G422-8. [PMID: 17585013 DOI: 10.1152/ajpgi.00083.2007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Spinal afferent neurons, with endings in the intestinal mesenteries, have been shown to respond to changes in vascular perfusion rates. The mechanisms underlying this sensitivity were investigated in an in vitro preparation of the mesenteric fan devoid of connections with the gut wall. Afferent discharge increased when vascular perfusion was stopped ("flow off"), a response localized to the terminal vessels just prior to where they entered the gut wall. The flow-off response was compared following pharmacological manipulations designed to determine direct mechanical activation from indirect mechanisms via the vascular endothelium or muscle. Under Ca(2+)-free conditions, responses to flow off were significantly augmented. In contrast, the myosin light chain kinase inhibitor wortmannin (1 microM, 20 min) did not affect the flow-off response despite blocking the vasoconstriction evoked by 10 microM l-phenylephrine. This ruled out active tension, generated by vascular smooth muscle, in the response to flow off. Passive changes caused by vessel collapse during flow off were speculated to affect sensory nerve terminals directly. The flow-off response was not affected by the N-, P-, and Q-type Ca(2+) channel blocker omega-conotoxin MVIIC (1 muM intra-arterially) or the P2X receptor/ion channel blocker PPADS (50 microM). However, ruthenium red (50 microM), a blocker of nonselective cation channels, greatly reduced the flow-off response and also abolished the vasodilator response to capsaicin. Our data support the concept that mesenteric afferents sense changes in vascular flow during flow off through direct mechanisms, possibly involving nonselective cation channels. Passive distortion in the fan, caused by changes in blood flow, may represent a natural stimulus for these afferents in vivo.
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Affiliation(s)
- A M Brunsden
- Department of Biomedical Science, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
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Shi J, Takahashi S, Jin XH, Li YQ, Ito Y, Mori Y, Inoue R. Myosin light chain kinase-independent inhibition by ML-9 of murine TRPC6 channels expressed in HEK293 cells. Br J Pharmacol 2007; 152:122-31. [PMID: 17603544 PMCID: PMC1978268 DOI: 10.1038/sj.bjp.0707368] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Myosin light chain kinase (MLCK) plays a pivotal role in regulation of cellular functions, the evidence often relying on the effects of extracelluarly administered drugs such as ML-9. Here we report that this compound exerts non-specific inhibitory actions on the TRPC6 channel, a transient receptor potential (TRP) protein. EXPERIMENTAL APPROACH Macroscopic and single channel currents were recorded from transfected HEK293 cells by patch-clamp techniques. KEY RESULTS Cationic currents elicited by carbachol (CCh; 100 microM) in HEK293 cells overexpressing murine TRPC6 (I(TRPC6)) were dose-dependently inhibited by externally applied ML-9 (IC(50)=7.8 microM). This inhibition was voltage-dependent and occurred as fast as external Na(+) removal. Another MLCK inhibitor, wortmannin (3 microM), and MLCK inhibitory peptides MLCK-IP(11-19) (10 microM) and -IP(480-501) (1 microM) showed little effects on I(TRPC6) density and the inhibitory efficacy of ML-9. The extent of the inhibition also unchanged with co-expression of wild-type or a dominant negative mutant of MLCK. Inhibitory effects of ML-9 on I(TRPC6) remained unaffected whether TRPC6 was activated constitutively or by a diacylglycerol analogue OAG (100 microM). Similar rapid inhibition was also observed with a ML-9 relative, ML-7. Intracellular perfusion of ML-9 via patch pipette, dose-dependently suppressed I(TRPC6). In inside-out patch configuration, bath application of ML-9 (and ML-7) rapidly diminished approximately 35pS single TRPC6 channel activities. Contrarily, currents due to TRPC7 expression were rapidly enhanced by externally applied ML-9 and ML-7, which was not prevented by MLCK inhibitory peptides. CONCLUSION AND IMPLICATIONS These results strongly suggest that ML compounds inhibit TRPC6 channels via a mechanism independent of inhibition of MLCK activity.
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Affiliation(s)
- J Shi
- Department of Anatomy and K.K Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
- Department of Physiology, Fukuoka University School of Medicine Fukuoka, Japan
- Department of Pharmacology, Graduate School of Medical Sciences, Kyushu University Fukuoka, Japan
| | - S Takahashi
- Department of Physiology, Fukuoka University School of Medicine Fukuoka, Japan
- Department of Pharmacology, Graduate School of Medical Sciences, Kyushu University Fukuoka, Japan
| | - X-H Jin
- Department of Histology and Embryology, The Fourth Military Medical University Xi'an, China
| | - Y-Q Li
- Department of Anatomy and K.K Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Y Ito
- Department of Pharmacology, Graduate School of Medical Sciences, Kyushu University Fukuoka, Japan
| | - Y Mori
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University Kyoto, Japan
| | - R Inoue
- Department of Physiology, Fukuoka University School of Medicine Fukuoka, Japan
- Author for correspondence:
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Wang J, Weigand L, Foxson J, Shimoda LA, Sylvester JT. Ca2+ signaling in hypoxic pulmonary vasoconstriction: effects of myosin light chain and Rho kinase antagonists. Am J Physiol Lung Cell Mol Physiol 2007; 293:L674-85. [PMID: 17575009 DOI: 10.1152/ajplung.00141.2007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Antagonists of myosin light chain (MLC) kinase (MLCK) and Rho kinase (ROK) are thought to inhibit hypoxic pulmonary vasoconstriction (HPV) by decreasing the concentration of phosphorylated MLC at any intracellular Ca(2+) concentration ([Ca(2+)](i)) in pulmonary arterial smooth muscle cells (PASMC); however, these antagonists can also decrease [Ca(2+)](i). To determine whether MLCK and ROK antagonists alter Ca(2+) signaling in HPV, we measured the effects of ML-9, ML-7, Y-27632, and HA-1077 on [Ca(2+)](i), Ca(2+) entry, and Ca(2+) release in rat distal PASMC exposed to hypoxia or depolarizing concentrations of KCl. We performed parallel experiments in isolated rat lungs to confirm the inhibitory effects of these agents on pulmonary vasoconstriction. Our results demonstrate that MLCK and ROK antagonists caused concentration-dependent inhibition of hypoxia-induced increases in [Ca(2+)](i) in PASMC and HPV in isolated lungs and suggest that this inhibition was due to blockade of Ca(2+) release from the sarcoplasmic reticulum and Ca(2+) entry through store- and voltage-operated Ca(2+) channels in PASMC. Thus MLCK and ROK antagonists might block HPV by inhibiting Ca(2+) signaling, as well as the actin-myosin interaction, in PASMC. If effects on Ca(2+) signaling were due to decreased phosphorylated myosin light chain concentration, their diversity suggests that MLCK and ROK antagonists may have acted by inhibiting myosin motors and/or altering the cytoskeleton in a manner that prevented achievement of required spatial relationships among the cellular components of the response.
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Affiliation(s)
- Jian Wang
- Division of Pulmonary & Critical Care Medicine, The Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA
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Schwarz BT, Wang F, Shen L, Clayburgh DR, Su L, Wang Y, Fu YX, Turner JR. LIGHT signals directly to intestinal epithelia to cause barrier dysfunction via cytoskeletal and endocytic mechanisms. Gastroenterology 2007; 132:2383-94. [PMID: 17570213 PMCID: PMC2709832 DOI: 10.1053/j.gastro.2007.02.052] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Accepted: 02/15/2007] [Indexed: 01/05/2023]
Abstract
BACKGROUND & AIMS LIGHT (lymphotoxin-like inducible protein that competes with glycoprotein D for herpes virus entry on T cells) is a tumor necrosis factor core family member that regulates T-cell activation and causes experimental inflammatory bowel disease. Additional data suggest that LIGHT may be involved in the pathogenesis of human inflammatory bowel disease. The aim of this study was to determine if LIGHT is capable of signaling directly to intestinal epithelia and to define the mechanisms and consequences of such signaling. METHODS The effects of LIGHT and interferon-gamma on barrier function, cytoskeletal regulation, and tight junction structure were assessed in mice and intestinal epithelial monolayers. RESULTS LIGHT induced barrier loss in cultured epithelia via myosin II regulatory light chain (MLC) phosphorylation; both barrier loss and MLC phosphorylation were reversed by MLC kinase (MLCK) inhibition. Pretreatment with interferon-gamma, which induced lymphotoxin beta receptor (LT beta R) expression, was required for these effects, and neither barrier dysfunction nor intestinal epithelial MLC phosphorylation occurred in LT beta R knockout mice. In cultured monolayers, endocytosis of the tight junction protein occludin correlated with barrier loss. Internalized occludin colocalized with caveolin-1. LIGHT-induced occludin endocytosis and barrier loss were both prevented by inhibition of caveolar endocytosis. CONCLUSIONS T cell-derived LIGHT activates intestinal epithelial LT beta R to disrupt barrier function. This requires MLCK activation and caveolar endocytosis. These data suggest a novel role for LIGHT in disease pathogenesis and suggest that inhibition of MLCK-dependent caveolar endocytosis may represent an approach to restoring barrier function in inflammatory bowel disease.
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Affiliation(s)
- Brad T. Schwarz
- Department of Pathology, The University of Chicago, Chicago IL, 60637
| | - Fengjun Wang
- Department of Pathology, The University of Chicago, Chicago IL, 60637
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Le Shen
- Department of Pathology, The University of Chicago, Chicago IL, 60637
| | | | - Liping Su
- Department of Pathology, The University of Chicago, Chicago IL, 60637
| | - Yingmin Wang
- Department of Pathology, The University of Chicago, Chicago IL, 60637
| | - Yang-Xin Fu
- Department of Pathology, The University of Chicago, Chicago IL, 60637
| | - Jerrold R. Turner
- Department of Pathology, The University of Chicago, Chicago IL, 60637
- Corresponding author: Department of Pathology, The University of Chicago, 5841 South Maryland Avenue, MC 1089, Chicago, IL 60637, (773) 702-2433; (773) 834-5251 (FAX);
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Ihara E, Edwards E, Borman MA, Wilson DP, Walsh MP, MacDonald JA. Inhibition of zipper-interacting protein kinase function in smooth muscle by a myosin light chain kinase pseudosubstrate peptide. Am J Physiol Cell Physiol 2007; 292:C1951-9. [PMID: 17215325 DOI: 10.1152/ajpcell.00434.2006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
As a regulator of smooth muscle contractility, zipper-interacting protein kinase (ZIPK) appears to phosphorylate the regulatory myosin light chain (RLC20), directly or indirectly, at Ser19 and Thr18 in a Ca2+-independent manner. The calmodulin-binding and autoinhibitory domain of myosin light chain kinase (MLCK) shares similarity to a sequence found in ZIPK. This similarity in sequence prompted an investigation of the SM1 peptide, which is derived from the autoinhibitory region of MLCK, as a potential inhibitor of ZIPK. In vitro studies showed that SM1 is a competitive inhibitor of a constitutively active 32-kDa form of ZIPK with an apparent Kivalue of 3.4 μM. Experiments confirmed that the SM1 peptide is also active against full-length ZIPK. In addition, ZIPK autophosphorylation was reduced by SM1. ZIPK activity is independent of calmodulin; however, calmodulin suppressed the in vitro inhibitory potential of SM1, likely as a result of nonspecific binding of the peptide to calmodulin. Treatment of ileal smooth muscle with exogenous ZIPK was accompanied by an increase in RLC20 diphosphorylation, distinguishing between ZIPK [and integrin-linked kinase (ILK)] and MLCK actions. Administration of SM1 suppressed steady-state muscle tension developed by the addition of exogenous ZIPK to Triton-skinned rat ileal muscle strips with or without calmodulin depletion by trifluoperazine. The decrease in contractile force was associated with decreases in both RLC20 mono- and diphosphorylation. In summary, we present the SM1 peptide as a novel inhibitor of ZIPK. We also conclude that the SM1 peptide, which has no effect on ILK, can be used to distinguish between ZIPK and ILK effects in smooth muscle tissues.
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Affiliation(s)
- Eikichi Ihara
- Smooth Muscle Research Group and Dept. of Biochemistry and Molecular Biology, University of Calgary, Faculty of Medicine, 3330 Hospital Dr. NW, Calgary, Alberta T2N 4N1, Canada
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Kim JI, Jeon SB, Baek I, Seok YM, Shin HM, Kim IK. Heat shock augments myosin phosphatase target-subunit phosphorylation. Biochem Biophys Res Commun 2007; 356:718-22. [PMID: 17382904 DOI: 10.1016/j.bbrc.2007.03.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Accepted: 03/07/2007] [Indexed: 11/19/2022]
Abstract
Our previous study demonstrated that heat shock augmented vascular contraction. In the present study, we hypothesized that heat shock augments myosin phosphatase target-subunit (MYPT1) phosphorylation resulting in augmented vascular contraction. Endothelium-denuded rat aortic rings were mounted in organ baths, exposed to heat shock (42 degrees C for 45 min), and subjected to contraction 4 h after the heat shock followed by Western blot analysis for MLC(20) (the 20 kDa light chains of myosin II) or MYPT1. The contractile responses in both control and heat shock-treated aorta were inhibited by Y27632, an inhibitor of Rho-kinase. The level of the MLC(20) and MYPT1(Thr855) phosphorylation in response to KCl was higher in heat shock-treated aorta than that in timed-control. The increased MYPT1(Thr855) phosphorylation was inhibited by Y27632 (1.0 microM) in parallel with inhibition of MLC(20) phosphorylation and vascular contraction. These results indicate that heat shock augments MYPT1 phosphorylation resulting in augmented vascular contraction.
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Affiliation(s)
- Jee In Kim
- Department of Pharmacology, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea
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Mbikou P, Fajmut A, Brumen M, Roux E. Theoretical and experimental investigation of calcium-contraction coupling in airway smooth muscle. Cell Biochem Biophys 2007; 46:233-52. [PMID: 17272850 DOI: 10.1385/cbb:46:3:233] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 11/11/2022]
Abstract
We investigated theoretically and experimentally the Ca2+-contraction coupling in rat tracheal smooth muscle. [Ca2+]i, isometric contraction and myosin light chain (MLC) phosphorylation were measured in response to 1 mM carbachol. Theoretical modeling consisted in coupling a model of Ca2+-dependent MLC kinase (MLCK) activation with a four-state model of smooth muscle contractile apparatus. Stimulation resulted in a short-time contraction obtained within 1 min, followed by a long-time contraction up to the maximal force obtained in 30 min. ML-7 and Wortmannin (MLCK inhibitors) abolished the contraction. Chelerythrine (PKC inhibitor) did not change the short-time, but reduced the long-time contraction. [Ca2+]i responses of isolated myocytes recorded during the first 90 s consisted in a fast peak, followed by a plateau phase and, in 28% of the cells, superimposed Ca2+ oscillations. MLC phosphorylation was maximal at 5 s and then decreased, whereas isometric contraction followed a Hill-shaped curve. The model properly predicts the time course of MLC phosphorylation and force of the short-time response. With oscillating Ca2+ signal, the predicted force does not oscillate. According to the model, the amplitude of the plateau and the frequency of oscillations encode for the amplitude of force, whereas the peak encodes for force velocity. The long-time phase of the contraction, associated with a second increase in MLC phosphorylation, may be explained, at least partially, by MLC phosphatase (MLCP) inhibition, possibly via PKC inhibition.
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Affiliation(s)
- Prisca Mbikou
- Université Bordeaux 2, Laboratoire de Physiologie Cellulaire Respiratoire, Bordeaux, F-33076 France; Inserm, E356, Bordeaux, F-33076 France
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46
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Matsumoto H, Moir LM, Oliver BGG, Burgess JK, Roth M, Black JL, McParland BE. Comparison of gel contraction mediated by airway smooth muscle cells from patients with and without asthma. Thorax 2007; 62:848-54. [PMID: 17412779 PMCID: PMC2094259 DOI: 10.1136/thx.2006.070474] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Exaggerated bronchial constriction is the most significant and life threatening response of patients with asthma to inhaled stimuli. However, few studies have investigated the contractility of airway smooth muscle (ASM) from these patients. The purpose of this study was to establish a method to measure contraction of ASM cells by embedding them into a collagen gel, and to compare the contraction between subjects with and without asthma. METHODS Gel contraction to histamine was examined in floating gels containing cultured ASM cells from subjects with and without asthma following overnight incubation while unattached (method 1) or attached (method 2) to casting plates. Smooth muscle myosin light chain kinase protein levels were also examined. RESULTS Collagen gels containing ASM cells reduced in size when stimulated with histamine in a concentration-dependent manner and reached a maximum at a mean (SE) of 15.7 (1.2) min. This gel contraction was decreased by inhibitors for phospholipase C (U73122), myosin light chain kinase (ML-7) and Rho kinase (Y27632). When comparing the two patient groups, the maximal decreased area of gels containing ASM cells from patients with asthma was 19 (2)% (n = 8) using method 1 and 22 (3)% (n = 6) using method 2, both of which were greater than that of cells from patients without asthma: 13 (2)% (n = 9, p = 0.05) and 10 (4)% (n = 5, p = 0.024), respectively. Smooth muscle myosin light chain kinase levels were not different between the two groups. CONCLUSION The increased contraction of asthmatic ASM cells may be responsible for exaggerated bronchial constriction in asthma.
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Affiliation(s)
- Hisako Matsumoto
- Discipline of Pharmacology, University of Sydney, NSW 2006, Australia.
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Sakata H, Sakabe M, Matsui H, Kawada N, Nakatani K, Ikeda K, Yamagishi T, Nakajima Y. Rho kinase inhibitor Y27632 affects initial heart myofibrillogenesis in cultured chick blastoderm. Dev Dyn 2007; 236:461-72. [PMID: 17195179 DOI: 10.1002/dvdy.21055] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
During early vertebrate development, Rho-associated kinases (ROCKs) are involved in various developmental processes. Here, we investigated spatiotemporal expression patterns of ROCK1 protein and examined the role of ROCK during initial heart myofibrillogenesis in cultured chick blastoderm. Immunohistochemistry showed that ROCK1 protein was distributed in migrating mesendoderm cells, visceral mesoderm of the pericardial coelom (from which cardiomyocytes will later develop), and cardiomyocytes of the primitive heart tube. Pharmacological inhibition of ROCK by Y27632 did not alter the myocardial specification process in cultured posterior blastoderm. However, Y27632 disturbed the formation of striated heart myofibrils in cultured posterior blastoderm. Furthermore, Y27632 affected the formation of costamere, a vinculin/integrin-based rib-like cell adhesion site. In such cardiomyocytes, cell-cell adhesion was disrupted and N-cadherin was distributed in the perinuclear region. Pharmacological inactivation of myosin light chain kinase, a downstream of ROCK, by ML-9 perturbed the formation of striated myofibrils as well as costameres, but not cell-cell adhesion. These results suggest that ROCK plays a role in the formation of initial heart myofibrillogenesis by means of actin-myosin assembly, and focal adhesion/costamere and cell-cell adhesion.
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Affiliation(s)
- Hirokazu Sakata
- Department of Anatomy and Cell Biology, Graduate School of Medicine, Osaka City University, Asahimachi, Osaka, Japan
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Hopkins AM, Pineda AA, Winfree LM, Brown GT, Laukoetter MG, Nusrat A. Organized migration of epithelial cells requires control of adhesion and protrusion through Rho kinase effectors. Am J Physiol Gastrointest Liver Physiol 2007; 292:G806-17. [PMID: 17138966 DOI: 10.1152/ajpgi.00333.2006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Migration of epithelial cell sheets, a process involving F-actin restructuring through Rho family GTPases, is both physiologically and pathophysiologically important. Our objective was to clarify the mechanisms whereby the downstream RhoA effector Rho-associated coil-coil-forming kinase (ROCK) influences coordinated epithelial cell motility. Although cells exposed to a pharmacological ROCK inhibitor (Y-27632) exhibited increased spreading in wound closure assays, they failed to migrate in a cohesive manner. Two main phenomena were implicated: the formation of aberrant protrusions at the migrating front and the basal accumulation of F-actin aggregates. Aggregates reflected increased membrane affiliation and detergent insolubility of the actin-binding protein ezrin and enhanced coassociation of ezrin with the membrane protein CD44. While F-actin aggregation following ROCK inhibition was recapitulated by inhibiting myosin light chain (MLC) phosphorylation with the MLC kinase inhibitor ML-7, the latter did not influence protrusiveness and, in fact, significantly decreased cell migration. Our results suggest that excessive protrusiveness downstream of ROCK inhibition reflects an influence of ROCK on F-actin stability via LIM kinase 1 (LIMK-1), which phosphorylates and inactivates cofilin. Y-27632 reduced the levels of both active LIMK-1 and inactive cofilin (phospho forms), and expression of a dominant negative LIMK-1 mutant stimulated leading edge protrusiveness. Furthermore, Y-27632-induced protrusions were partially reversed by overexpression of LIMK-1 to restore cofilin phosphorylation. In summary, our results provide new evidence suggesting that adhesive and protrusive events involved in organized epithelial motility downstream of ROCK are separately coordinated through the phosphorylation of (respectively) MLC and cofilin.
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Affiliation(s)
- Ann M Hopkins
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia 30322, USA.
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Kuhlmann CRW, Tamaki R, Gamerdinger M, Lessmann V, Behl C, Kempski OS, Luhmann HJ. Inhibition of the myosin light chain kinase prevents hypoxia-induced blood-brain barrier disruption. J Neurochem 2007; 102:501-7. [PMID: 17419808 DOI: 10.1111/j.1471-4159.2007.04506.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Increased mortality after stroke is associated with development of brain edema. The aim of the present study was to examine the contribution of endothelial myosin light chain (MLC) phosphorylation to hypoxia-induced blood-brain barrier (BBB) opening. Measurements of trans-endothelial electrical resistance (TEER) were performed to analyse BBB integrity in an in vitro co-culture model (bovine brain microvascular endothelial cells (BEC) and rat astrocytes). Brain fluid content was analysed in rats after stroke induction using a two-vein occlusion model. Dihydroethidium was used to monitor intracellular generation of reactive oxygen species (ROS) in BEC. MLC phosphorylation was detected using immunohistochemistry and immunoblot analysis. Hypoxia caused a decrease of TEER values by more than 40%, which was prevented by inhibition of the MLC-kinase (ML-7, 10 micromol/L). In addition, ML-7 significantly reduced the brain fluid content in vivo after stroke. The NAD(P)H-oxidase inhibitor apocynin (500 micromol/L) prevented the hypoxia-induced TEER decrease. Hypoxia-dependent ROS generation was completely abolished by apocynin. Furthermore, ML-7 and apocynin blocked hypoxia-dependent phosphorylation of MLC. Our data demonstrate that hypoxia causes a breakdown of the BBB in vitro and in vivo involving ROS and the contractile machinery.
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Affiliation(s)
- Christoph R W Kuhlmann
- Institute of Physiology and Pathophysiology, Johannes Gutenberg University of Mainz, Mainz, Germany.
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Clark K, Langeslag M, Figdor CG, van Leeuwen FN. Myosin II and mechanotransduction: a balancing act. Trends Cell Biol 2007; 17:178-86. [PMID: 17320396 DOI: 10.1016/j.tcb.2007.02.002] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Accepted: 02/08/2007] [Indexed: 10/25/2022]
Abstract
Adherent cells respond to mechanical properties of the surrounding extracellular matrix. Mechanical forces, sensed at specialized cell-matrix adhesion sites, promote actomyosin-based contraction within the cell. By manipulating matrix rigidity and adhesion strength, new roles for actomyosin contractility in the regulation of basic cellular functions, including cell proliferation, migration and stem cell differentiation, have recently been discovered. These investigations demonstrate that a balance of forces between cell adhesion on the outside and myosin II-based contractility on the inside of the cell controls many aspects of cell behavior. Disturbing this balance contributes to the pathogenesis of various human diseases. Therefore, elaborate signaling networks have evolved that modulate myosin II activity to maintain tensional homeostasis. These include signaling pathways that regulate myosin light chain phosphorylation as well as myosin II heavy chain interactions.
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Affiliation(s)
- Kristopher Clark
- Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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