1
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Novel approaches to antiplatelet therapy. Biochem Pharmacol 2022; 206:115297. [DOI: 10.1016/j.bcp.2022.115297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/05/2022] [Accepted: 10/05/2022] [Indexed: 11/20/2022]
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2
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Cook GM, Sousa C, Schaeffer J, Wiles K, Jareonsettasin P, Kalyanasundaram A, Walder E, Casper C, Patel S, Chua PW, Riboni-Verri G, Raza M, Swaddiwudhipong N, Hui A, Abdullah A, Wajed S, Keynes RJ. Regulation of nerve growth and patterning by cell surface protein disulphide isomerase. eLife 2020; 9:54612. [PMID: 32452761 PMCID: PMC7269675 DOI: 10.7554/elife.54612] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 05/23/2020] [Indexed: 02/06/2023] Open
Abstract
Contact repulsion of growing axons is an essential mechanism for spinal nerve patterning. In birds and mammals the embryonic somites generate a linear series of impenetrable barriers, forcing axon growth cones to traverse one half of each somite as they extend towards their body targets. This study shows that protein disulphide isomerase provides a key component of these barriers, mediating contact repulsion at the cell surface in chick half-somites. Repulsion is reduced both in vivo and in vitro by a range of methods that inhibit enzyme activity. The activity is critical in initiating a nitric oxide/S-nitrosylation-dependent signal transduction pathway that regulates the growth cone cytoskeleton. Rat forebrain grey matter extracts contain a similar activity, and the enzyme is expressed at the surface of cultured human astrocytic cells and rat cortical astrocytes. We suggest this system is co-opted in the brain to counteract and regulate aberrant nerve terminal growth.
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Affiliation(s)
- Geoffrey Mw Cook
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Catia Sousa
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,Grenoble Institute des Neurosciences, La Tronche, France
| | - Julia Schaeffer
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Katherine Wiles
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,Independent researcher, London, United Kingdom
| | - Prem Jareonsettasin
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,Exeter College, Oxford, United Kingdom
| | - Asanish Kalyanasundaram
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,School of Clinical Medicine, Cambridge University Hospitals, Cambridge, United Kingdom
| | - Eleanor Walder
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,School of Clinical Medicine, Cambridge University Hospitals, Cambridge, United Kingdom
| | - Catharina Casper
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,Winter, Brandl, Fürniss, Hübner, Röss, Kaiser & Polte, Partnerschaft mbB, Patent und Rechtsanwaltskanzlei, München, Germany
| | - Serena Patel
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,School of Clinical Medicine, Cambridge University Hospitals, Cambridge, United Kingdom
| | - Pei Wei Chua
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,School of Medicine and Health Sciences, Monash University, Bandar Sunway, Malaysia
| | - Gioia Riboni-Verri
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,School of Medicine, Medical Science and Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Mansoor Raza
- Cambridge Innovation Capital, Cambridge, United Kingdom
| | - Nol Swaddiwudhipong
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Andrew Hui
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Ameer Abdullah
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Saj Wajed
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,University of Exeter Medical School, Exeter, United Kingdom
| | - Roger J Keynes
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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3
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Pan S, Chen HH, Correia C, Dai H, Witt TA, Kleppe LS, Burnett JC, Simari RD. Cell surface protein disulfide isomerase regulates natriuretic peptide generation of cyclic guanosine monophosphate. PLoS One 2014; 9:e112986. [PMID: 25419565 PMCID: PMC4242536 DOI: 10.1371/journal.pone.0112986] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 10/21/2014] [Indexed: 12/21/2022] Open
Abstract
Rationale The family of natriuretic peptides (NPs), including atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), and C-type natriuretic peptide (CNP), exert important and diverse actions for cardiovascular and renal homeostasis. The autocrine and paracrine functions of the NPs are primarily mediated through the cellular membrane bound guanylyl cyclase-linked receptors GC-A (NPR-A) and GC-B (NPR-B). As the ligands and receptors each contain disulfide bonds, a regulatory role for the cell surface protein disulfide isomerase (PDI) was investigated. Objective We utilized complementary in vitro and in vivo models to determine the potential role of PDI in regulating the ability of the NPs to generate its second messenger, cyclic guanosine monophosphate. Methods and Results Inhibition of PDI attenuated the ability of ANP, BNP and CNP to generate cGMP in human mesangial cells (HMCs), human umbilical vein endothelial cells (HUVECs), and human aortic smooth muscle cells (HASMCs), each of which were shown to express PDI. In LLC-PK1 cells, where PDI expression was undetectable by immunoblotting, PDI inhibition had a minimal effect on cGMP generation. Addition of PDI to cultured LLC-PK1 cells increased intracellular cGMP generation mediated by ANP. Inhibition of PDI in vivo attenuated NP-mediated generation of cGMP by ANP. Surface Plasmon Resonance demonstrated modest and differential binding of the natriuretic peptides with immobilized PDI in a cell free system. However, PDI was shown to co-localize on the surface of cells with GC-A and GC-B by co-immunoprecpitation and immunohistochemistry. Conclusion These data demonstrate for the first time that cell surface PDI expression and function regulate the capacity of natriuretic peptides to generate cGMP through interaction with their receptors.
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Affiliation(s)
- Shuchong Pan
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States of America
| | - Horng H. Chen
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States of America
| | - Cristina Correia
- Division of Oncology Research, Mayo Clinic, Rochester, MN, United States of America
| | - Haiming Dai
- Division of Oncology Research, Mayo Clinic, Rochester, MN, United States of America
| | - Tyra A. Witt
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States of America
| | - Laurel S. Kleppe
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States of America
| | - John C. Burnett
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States of America
| | - Robert D. Simari
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States of America
- * E-mail:
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4
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Ciesiołka J, Jeżowska-Bojczuk M, Wrzesiński J, Stokowa-Sołtys K, Nagaj J, Kasprowicz A, Błaszczyk L, Szczepanik W. Antibiotic bacitracin induces hydrolytic degradation of nucleic acids. Biochim Biophys Acta Gen Subj 2014; 1840:1782-9. [DOI: 10.1016/j.bbagen.2014.01.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 01/16/2014] [Accepted: 01/29/2014] [Indexed: 10/25/2022]
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5
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Flaumenhaft R. Protein disulfide isomerase as an antithrombotic target. Trends Cardiovasc Med 2013; 23:264-8. [PMID: 23541171 DOI: 10.1016/j.tcm.2013.03.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 02/19/2013] [Accepted: 02/20/2013] [Indexed: 01/21/2023]
Abstract
Protein disulfide isomerase (PDI) is a ubiquitously expressed oxidoreductase required for proper protein folding. It is highly concentrated in the endoplasmic reticulum, but can also be released into the extracellular environment. Several in vivo thrombosis models have demonstrated that vascular PDI secreted by platelets and endothelial cells is essential for normal thrombus formation. Inhibition of extracellular PDI thus represents a potential strategy for antithrombotic therapy. Yet this approach requires the discovery of well-tolerated PDI inhibitors. A recent high-throughput screening identified the commonly ingested flavonoid, quercetin-3-rutinoside, as an inhibitor of PDI. Quercetin-3-rutinoside blocked thrombus formation at concentrations that are commonly ingested as nutritional supplements. The observation that a compound with Generally Recognized As Safe status inhibits PDI and blocks thrombosis in animal models forms a rationale for clinical trials evaluating PDI inhibitors as a new class of antithrombotics.
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Affiliation(s)
- Robert Flaumenhaft
- Division of Hemostasis and Thrombosis, Department of Medicine, BIDMC, Harvard Medical School, Boston, MA, USA.
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6
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Opposing effects of bacitracin on human papillomavirus type 16 infection: enhancement of binding and entry and inhibition of endosomal penetration. J Virol 2012; 86:4169-81. [PMID: 22345461 DOI: 10.1128/jvi.05493-11] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cell invasion by human papillomavirus type 16 (HPV16) is a complex process relying on multiple host cell factors. Here we describe an investigation into the role of cellular protein disulfide isomerases (PDIs) by studying the effects of the commonly used PDI inhibitor bacitracin on HPV16 infection. Bacitracin caused an unusual time-dependent opposing effect on viral infection. Enhanced cellular binding and entry were observed at early times of infection, while inhibition was observed at later times postentry. Bacitracin was rapidly taken up by host cells and colocalized with HPV16 at late times of infection. Bacitracin had no deleterious effect on HPV16 entry, capsid disassembly, exposure of L1/L2 epitopes, or lysosomal trafficking but caused a stark inhibition of L2/viral DNA (vDNA) endosomal penetration and accumulation at nuclear PML bodies. γ-Secretase has recently been implicated in the endosomal penetration of L2/vDNA, but bacitracin had no effect on γ-secretase activity, indicating that blockage of this step occurs through a γ-secretase-independent mechanism. Transient treatment with the reductant β-mercaptoethanol (β-ME) was able to partially rescue the virus from bacitracin, suggesting the involvement of a cellular reductase activity in HPV16 infection. Small interfering RNA (siRNA) knockdown of cellular PDI and the related PDI family members ERp57 and ERp72 reveals a potential role for PDI and ERp72 in HPV infection.
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7
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McLaughlin M, Vandenbroeck K. The endoplasmic reticulum protein folding factory and its chaperones: new targets for drug discovery? Br J Pharmacol 2011; 162:328-45. [PMID: 20942857 DOI: 10.1111/j.1476-5381.2010.01064.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Cytosolic heat shock proteins have received significant attention as emerging therapeutic targets. Much of this excitement has been triggered by the discovery that HSP90 plays a central role in the maintenance and stability of multifarious oncogenic membrane receptors and their resultant tyrosine kinase activity. Numerous studies have dealt with the effects of small molecules on chaperone- and stress-related pathways of the endoplasmic reticulum (ER). However, unlike cytosolic chaperones, relatively little emphasis has been placed upon translational avenues towards targeting of the ER for inhibition of folding/secretion of disease-promoting proteins. Here, we summarise existing small molecule inhibitors and potential future targets of ER chaperone-mediated inhibition. Client proteins of translational relevance in disease treatment are outlined, alongside putative future disease treatment modalities based on ER-centric targeted therapies. Particular attention is paid to cancer and autoimmune disorders via the effects of the GRP94 inhibitor geldanamycin and its population of client proteins, overloading of the unfolded protein response, and inhibition of members of the IL-12 family of cytokines by celecoxib and non-coxib analogues.
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8
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Bi S, Hong PW, Lee B, Baum LG. Galectin-9 binding to cell surface protein disulfide isomerase regulates the redox environment to enhance T-cell migration and HIV entry. Proc Natl Acad Sci U S A 2011; 108:10650-5. [PMID: 21670307 PMCID: PMC3127870 DOI: 10.1073/pnas.1017954108] [Citation(s) in RCA: 173] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Interaction of cell surface glycoproteins with endogenous lectins on the cell surface regulates formation and maintenance of plasma membrane domains, clusters signaling complexes, and controls the residency time of glycoproteins on the plasma membrane. Galectin-9 is a soluble, secreted lectin that binds to glycoprotein receptors to form galectin-glycoprotein lattices on the cell surface. Whereas galectin-9 binding to specific glycoprotein receptors induces death of CD4 Th1 cells, CD4 Th2 cells are resistant to galectin-9 death due to alternative glycosylation. On Th2 cells, galectin-9 binds cell surface protein disulfide isomerase (PDI), increasing retention of PDI on the cell surface and altering the redox status at the plasma membrane. Cell surface PDI regulates integrin function on platelets and also enhances susceptibility of T cells to infection with HIV. We find that galectin-9 binding to PDI on Th2 cells results in increased cell migration through extracellular matrix via β3 integrins, identifying a unique mechanism to regulate T-cell migration. In addition, galectin-9 binding to PDI on T cells potentiates infection with HIV. We identify a mechanism for regulating cell surface redox status via a galectin-glycoprotein lattice, to regulate distinct T-cell functions.
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Affiliation(s)
- Shuguang Bi
- Departments of Pathology and Laboratory Medicine and
| | - Patrick W. Hong
- Microbiology, Immunology, and Molecular Genetics, University of California School of Medicine, Los Angeles, CA 90095
| | - Benhur Lee
- Departments of Pathology and Laboratory Medicine and
- Microbiology, Immunology, and Molecular Genetics, University of California School of Medicine, Los Angeles, CA 90095
| | - Linda G. Baum
- Departments of Pathology and Laboratory Medicine and
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9
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Dickerhof N, Kleffmann T, Jack R, McCormick S. Bacitracin inhibits the reductive activity of protein disulfide isomerase by disulfide bond formation with free cysteines in the substrate-binding domain. FEBS J 2011; 278:2034-43. [PMID: 21481187 DOI: 10.1111/j.1742-4658.2011.08119.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The peptide antibiotic bacitracin is widely used as an inhibitor of protein disulfide isomerase (PDI) to demonstrate the role of the protein-folding catalyst in a variety of molecular pathways. Commercial bacitracin is a mixture of at least 22 structurally related peptides. The inhibitory activity of individual bacitracin analogs on PDI is unknown. For the present study, we purified the major bacitracin analogs, A, B, H, and F, and tested their ability to inhibit the reductive activity of PDI by use of an insulin aggregation assay. All analogs inhibited PDI, but the activity (IC(50) ) ranged from 20 μm for bacitracin F to 1050 μm for bacitracin B. The mechanism of PDI inhibition by bacitracin is unknown. Here, we show, by MALDI-TOF/TOF MS, a direct interaction of bacitracin with PDI, involving disulfide bond formation between an open thiol form of the bacitracin thiazoline ring and cysteines in the substrate-binding domain of PDI.
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Affiliation(s)
- Nina Dickerhof
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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10
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Koh A, Nishimura K, Urade R. Relationship between endogenous protein disulfide isomerase family proteins and glutenin macropolymer. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:12970-5. [PMID: 21087045 DOI: 10.1021/jf103347p] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The effects of endogenous protein disulfide isomerase (PDI) family proteins on the properties of gluten proteins in dough during breadmaking were determined using bacitracin, an inhibitor of PDI. Bread loaf volume in the presence of bacitracin was increased to 118% of that in the absence of bacitracin. The addition of bacitracin caused a decrease in the extension tolerance of the dough. The amount of sodium dodecyl sulfate (SDS)-insoluble glutenin macropolymer (GMP) in dough decreased to approximately 70% of that in flour during the 20 min of mixing for doughmaking. The addition of bacitracin to dough caused a dramatic GMP decrease, corresponding to ∼20-30% of that in flour during the 20 min of mixing. The decrease in GMP was compensated by an increase in SDS-soluble glutenin polymer. Taken together, these results suggest that the endogenous PDI family proteins in flour suppress the depolymerization of GMP during dough mixing.
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Affiliation(s)
- Akie Koh
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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11
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Abstract
To successfully dissect molecular pathways in vivo, there is often a need to use specific inhibitors. Bacitracin is very widely used as an inhibitor of protein disulfide isomerase (PDI) in vivo. However, the specificity of action of an inhibitor for a protein-folding catalyst cannot be determined in vivo. Furthermore, in vitro evidence for the specificity of bacitracin for PDI is scarce, and the mechanism of inhibition is unknown. Here, we present in vitro data showing that 1 mM bacitracin has no significant effect on the ability of PDI to introduce or isomerize disulfide bonds in a folding protein or on its ability to act as a chaperone. Where bacitracin has an effect on PDI activity, the effect is relatively minor and appears to be via competition of substrate binding. Whereas 1 mM bacitracin has minimal effects on PDI, it has significant effects on both noncatalyzed protein folding and on other molecular chaperones. These results suggest that the use of bacitracin as a specific inhibitor of PDI in cellular systems requires urgent re-evaluation.
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Affiliation(s)
- Anna-Riikka Karala
- Biocenter Oulu and Department of Biochemistry, University of Oulu, Oulu, Finland
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12
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Pendurthi UR, Ghosh S, Mandal SK, Rao LVM. Tissue factor activation: is disulfide bond switching a regulatory mechanism? Blood 2007; 110:3900-8. [PMID: 17726162 PMCID: PMC2190609 DOI: 10.1182/blood-2007-07-101469] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A majority of tissue factor (TF) on cell surfaces exists in a cryptic form (ie, coagulation function inactive) but retains its functionality in cell signaling. Recent studies have suggested that cryptic TF contains unpaired cysteine thiols and that activation involves the formation of the disulfide bond Cys186-Cys 209 and that protein disulfide isomerase (PDI) regulates TF coagulant and signaling activities by targeting this disulfide bond. This study was carried out to investigate the validity of this novel concept. Although treatment of MDA 231 tumor cells, fibroblasts, and stimulated endothelial cells with the oxidizing agent HgCl(2) markedly increased the cell-surface TF coagulant activity, the increase is associated with increased anionic phospholipids at the cell surface. Annexin V, which binds to anionic phospholipids, attenuated the increased TF coagulant activity. It is noteworthy that treatment of cells with reducing agents also increased the cell surface TF activity. No evidence was found for either detectable expression of PDI at the cell surface or association of TF with PDI. Furthermore, reduction of PDI with the gene silencing had no effect on either TF coagulant or cell signaling functions. Overall, the present data undermine the recently proposed hypothesis that PDI-mediated disulfide exchange plays a role in regulating TF procoagulant and cell signaling functions.
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Affiliation(s)
- Usha R Pendurthi
- Biomedical Research Division, University of Texas Health Science Center at Tyler, TX 75708, USA.
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13
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Versteeg HH, Ruf W. Tissue factor coagulant function is enhanced by protein-disulfide isomerase independent of oxidoreductase activity. J Biol Chem 2007; 282:25416-24. [PMID: 17613528 DOI: 10.1074/jbc.m702410200] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Protein-disulfide isomerase (PDI) switches tissue factor (TF) from coagulation to signaling by targeting the allosteric Cys186-Cys209 disulfide. Here, we further characterize the interaction of purified PDI with TF. We find that PDI enhances factor VIIa-dependent substrate factor X activation 5-10-fold in the presence of wild-type, oxidized soluble TF but not TF mutants that contain an unpaired Cys186 or Cys209. PDI-accelerated factor Xa generation was blocked by bacitracin but not influenced by inhibition of vicinal thiols, reduction of PDI, changes in redox gradients, or covalent thiol modification of reduced PDI by N-ethylmaleimide or methyl-methanethiosulfonate, which abolished PDI oxidoreductase but not chaperone activity. PDI had no effect on fully active TF on either negatively charged phospholipids or in activating detergent, indicating that PDI selectively acts upon cryptic TF to facilitate ternary complex formation and macromolecular substrate turnover. PDI activation was reduced upon mutation of TF residues in proximity to the macromolecular substrate binding site, consistent with a primary interaction of PDI with TF. PDI enhanced TF coagulant activity on microvesicles shed from cells, suggesting that PDI plays a role as an activating chaperone for circulating cryptic TF.
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Affiliation(s)
- Henri H Versteeg
- Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA
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14
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Park SH, Kwon JH, Lim SH, Park HW, Kim CW. Characterization of human insulin microcrystals and their absorption enhancement by protease inhibitors in rat lungs. Int J Pharm 2007; 339:205-12. [PMID: 17451895 DOI: 10.1016/j.ijpharm.2007.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Revised: 02/28/2007] [Accepted: 03/06/2007] [Indexed: 11/21/2022]
Abstract
Pulmonary route appears to be an attractive alternative as a non-invasive systemic delivery for peptide and protein drugs. An appropriate formulation, however, is important for increasing their bioavailability in lung. In this study, the human insulin microcrystals were produced. The particle size analysis and scanning electron microscopy (SEM) showed that the microcrystals were uniform and had a monodispersed size distribution (mean diameter = 0.95 microm) for pulmonary delivery. The physicochemical properties of the microcrystals developed were similar to those of the commercial crystalline powder in powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses. The percentage of high molecular weight proteins (%HMWP), the percentage of other insulin related compounds (%OIRC) and the percentage of A-21 desamido insulin (%D) of the microcrystals were very low. In addition, the cytotoxicity of microcrystals developed and protease inhibitors (aprotinin, bacitracin and soybean-trypsin inhibitor) was investigated, and the enhancement of insulin absorption in the presence of these protease inhibitors at various concentrations was studied. The cell viability of A549 was over 80% at various concentrations of aprotinin and soybean-trypsin inhibitor, except for bacitracin (below 60%). The percent of decrease in blood glucose (D%) was 42.68+/-1.62% after intratracheal instillation of insulin microcrystals (5 U/kg). An enhancement of hypoglycemic effect with protease inhibitors was also found. Soybean-trypsin inhibitor (48.86+/-3.24% at 10 mg/ml; 55.78+/-0.71% at 5 mg/ml; 51.49+/-5.27% at 1 mg/ml) and aprotinin (52.57+/-8.78% at 10 mg/ml; 51.97+/-1.98% at 5 mg/ml; 56.90+/-3.42% at 1 mg/ml) were effective for absorption enhancement. These findings suggest that the use of insulin microcrystals and protease inhibitors would be useful to improve the hypoglycemic effect in pulmonary route.
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Affiliation(s)
- Sang-Ha Park
- School of Life Sciences and Biotechnology, Korea University, 5-1, Anam-dong, Sungbuk-gu, Seoul 136-701, Republic of Korea
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15
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Ahamed J, Versteeg HH, Kerver M, Chen VM, Mueller BM, Hogg PJ, Ruf W. Disulfide isomerization switches tissue factor from coagulation to cell signaling. Proc Natl Acad Sci U S A 2006; 103:13932-7. [PMID: 16959886 PMCID: PMC1599891 DOI: 10.1073/pnas.0606411103] [Citation(s) in RCA: 279] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cell-surface tissue factor (TF) binds the serine protease factor VIIa to activate coagulation or, alternatively, to trigger signaling through the G protein-coupled, protease-activated receptor 2 (PAR2) relevant to inflammation and angiogenesis. Here we demonstrate that TF.VIIa-mediated coagulation and cell signaling involve distinct cellular pools of TF. The surface-accessible, extracellular Cys186-Cys209 disulfide bond of TF is critical for coagulation, and protein disulfide isomerase (PDI) disables coagulation by targeting this disulfide. A TF mutant (TF C209A) with an unpaired Cys186 retains TF.VIIa signaling activity, and it has reduced affinity for VIIa, a characteristic of signaling TF on cells with constitutive TF expression. We further show that PDI suppresses TF coagulant activity in a nitric oxide-dependent pathway, linking the regulation of TF thrombogenicity to oxidative stress in the vasculature. Furthermore, a unique monoclonal antibody recognizes only the noncoagulant, cryptic conformation of TF. This antibody inhibits formation of the TF.PAR2 complex and TF.VIIa signaling, but it does not prevent coagulation activation. These experiments delineate an upstream regulatory mechanism that controls TF function, and they provide initial evidence that TF.VIIa signaling can be specifically inhibited with minimal effects on coagulation.
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Affiliation(s)
- Jasimuddin Ahamed
- *Department of Immunology, The Scripps Research Institute, SP258, 10550 North Torrey Pines Road, La Jolla, CA 92037
| | - Henri H. Versteeg
- *Department of Immunology, The Scripps Research Institute, SP258, 10550 North Torrey Pines Road, La Jolla, CA 92037
| | - Marjolein Kerver
- *Department of Immunology, The Scripps Research Institute, SP258, 10550 North Torrey Pines Road, La Jolla, CA 92037
| | - Vivien M. Chen
- Centre for Vascular Research, University of New South Wales, Sydney 2052, Australia; and
| | | | - Philip J. Hogg
- Centre for Vascular Research, University of New South Wales, Sydney 2052, Australia; and
| | - Wolfram Ruf
- *Department of Immunology, The Scripps Research Institute, SP258, 10550 North Torrey Pines Road, La Jolla, CA 92037
- To whom correspondence should be addressed. E-mail:
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16
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Robinson A, O'Neill S, Kiernan A, O'Donoghue N, Moran N. Bacitracin reveals a role for multiple thiol isomerases in platelet function. Br J Haematol 2006; 132:339-48. [PMID: 16409299 DOI: 10.1111/j.1365-2141.2005.05878.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The platelet-specific integrin alphaIIb beta3 has endogenous thiol isomerase activity associated with the CXXC motifs within the beta subunit. Using a highly purified form of bacitracin, a thiol isomerase inhibitor, we now provide further evidence of the functional significance of this enzymatic activity in integrin activation. In addition, we demonstrate a role for multiple thiol isomerases in platelet function. This bacitracin prevented platelet aggregation to thrombin and collagen, and directly inhibited alphaIIb beta3 activation, as detected by PAC-1 binding. In parallel, bacitracin inhibited the endogenous thiol isomerase activity of purified alphaIIb beta3 with a 50% inhibitory concentration of 15.5 micromol/l. In order to determine whether the effects of bacitracin are solely mediated by inhibition of integrin enzymatic activity, we examined integrin-independent indices of platelet activation. We found bacitracin inhibited both platelet secretion (CD62P and CD63) and thromboxane (TxA2) production, with complete inhibition at different concentrations. Thus, we demonstrated a role for multiple thiol isomerases in platelet function. Taken together, these studies support a role for the endogenous integrin thiol isomerase activity in activation of alphaIIb beta3 and highlight the novel regulation of platelet function by other, as yet undefined thiol isomerases.
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Affiliation(s)
- Aisling Robinson
- Department of Clinical Pharmacology, Royal College of Surgeons in Ireland, Dublin 2, Ireland
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17
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Lahav J, Wijnen EM, Hess O, Hamaia SW, Griffiths D, Makris M, Knight CG, Essex DW, Farndale RW. Enzymatically catalyzed disulfide exchange is required for platelet adhesion to collagen via integrin alpha2beta1. Blood 2003; 102:2085-92. [PMID: 12791669 DOI: 10.1182/blood-2002-06-1646] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Integrin alpha2beta1 is the principal adhesive receptor for collagen but platelets also adhere through glycoprotein VI (GPVI). Integrin alphaIIbbeta3 may augment platelet adhesion. We have shown that disulfide exchange is necessary for platelet adhesion to fibrinogen, fibronectin, and collagen. However 2 questions remained: (1) Can activated alphaIIbbeta3 explain the observed role of disulfide exchange in adhesion to collagen, or is this role common to other integrins? (2) Is disulfide dependence specific to the integrin receptors or shared with GPVI? To discriminate adhesive functions of alpha2beta1 from those of alphaIIbbeta3 we used Glanzmann platelets and alphaIIbbeta3-specific antibodies applied to normal platelets. To resolve adhesive events mediated by alpha2beta1 from those of GPVI we used synthetic peptides specific to each receptor. We addressed direct integrin ligation using purified alpha2beta1 and recombinant I domain. We observed the following: adhesion to the alpha2beta1-specific peptide was disulfide-exchange dependent and protein disulfide isomerase (PDI) mediated; membrane-impermeant thiol blockers inhibited alpha2beta1, but not GPVI mediated, adhesion; direct blockade of PDI revealed that it is involved in adhesion through alpha2beta1 but not GPVI; and purified alpha2beta1, but not recombinant I domain, depended on free thiols for ligation. These data suggest that the enzymatically catalyzed adhesion-associated reorganization of disulfide bonds is common to members of the integrin family and specific to this family.
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Affiliation(s)
- Judith Lahav
- The Coagulation Laboratory, Rabin Medical Center-Beilinson Campus, Zabotinski St, Petah-Tiqva 49100, Israel.
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18
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Ohki R, Tateno K, Okada Y, Okajima H, Asai K, Sadaie Y, Murata M, Aiso T. A bacitracin-resistant Bacillus subtilis gene encodes a homologue of the membrane-spanning subunit of the Bacillus licheniformis ABC transporter. J Bacteriol 2003; 185:51-9. [PMID: 12486040 PMCID: PMC141914 DOI: 10.1128/jb.185.1.51-59.2003] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacitracin is a peptide antibiotic nonribosomally produced by Bacillus licheniformis. The bcrABC genes which confer bacitracin resistance to the bacitracin producer encode ATP binding cassette (ABC) transporter proteins, which are hypothesized to pump out bacitracin from the cells. Bacillus subtilis 168, which has no bacitracin synthesizing operon, has several genes homologous to bcrABC. It was found that the disruption of ywoA, a gene homologous to bcrC, resulted in hypersensitivity to bacitracin. Resistance to other drugs such as surfactin, iturin A, vancomycin, tunicamycin, gramicidin D, valinomycin and several cationic dyes were not changed in the ywoA disruptant. Spontaneous bacitracin-resistant mutants (Bcr-1 and -2) isolated in the presence of bacitracin have a single base substitution from A to G in the ribosome binding region. Northern hybridization analysis and determination of the expression of ywoA-LacZ transcriptional fusion gene revealed that the transcription of the ywoA gene was dependent on extracytoplasmic function (ECF) sigma factors sigma(M) and sigma(X). Preincubation of wild-type cells in the presence of a low concentration of bacitracin induced increased resistance to bacitracin about two- to threefold, although the mechanism of this induction has not yet been elucidated. It has been reported that a commercially available bacitracin is a mixture of several components and also contains impurity. Bacitracin A was purified by reverse phase high-performance liquid chromatography (HPLC). Similar results were obtained with bacitracin A as those with crude bacitracin, indicating that contaminating substances were not responsible for the results obtained in this study.
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Affiliation(s)
- Reiko Ohki
- Department of Molecular Biolog, School of Health Sciences, Kyorin University, 476 Miyashita, Hachioji, Tokyo 192-0005, Japan.
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19
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Turano C, Coppari S, Altieri F, Ferraro A. Proteins of the PDI family: unpredicted non-ER locations and functions. J Cell Physiol 2002; 193:154-63. [PMID: 12384992 DOI: 10.1002/jcp.10172] [Citation(s) in RCA: 388] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Protein disulfide isomerases (PDIs) constitute a family of structurally related enzymes which catalyze disulfide bonds formation, reduction, or isomerization of newly synthesized proteins in the lumen of the endoplasmic reticulum (ER). They act also as chaperones, and are, therefore, part of a quality-control system for the correct folding of the proteins in the same subcellular compartment. While their functions in the ER have been thoroughly studied, much less is known about their roles in non-ER locations, where, however, they have been shown to be involved in important biological processes. At least three proteins of this family from higher vertebrates have been found in unusual locations (i.e., the cell surface, the extracellular space, the cytosol, and the nucleus), reached through an export mechanism which has not yet been understood. In some cases their function in the non-ER location is clearly related to their redox properties, but in most cases their mechanism of action has still to be disclosed, although their propensity to associate with other proteins or even with DNA might be the main factor responsible for their activities.
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Affiliation(s)
- Carlo Turano
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche 'Alessandro Rossi-Fanelli' and Centro di Biologia Molecolare del CNR, Università 'La Sapienza', Rome, Italy.
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20
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Weston BS, Wahab NA, Roberts T, Mason RM. Bacitracin inhibits fibronectin matrix assembly by mesangial cells in high glucose. Kidney Int 2001; 60:1756-64. [PMID: 11703593 DOI: 10.1046/j.1523-1755.2001.00991.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Accumulation of mesangial extracellular matrix is a major characteristic of diabetic nephropathy (DN). Expression of several extracellular matrix proteins is up-regulated in human mesangial cells (HMC) cultured in high glucose. One protein, fibronectin (FN), associates to form an insoluble disulfide-linked matrix and possesses inherent protein-disulfide isomerase (PDI) activity. Bacitracin is a known PDI inhibitor. We tested the hypothesis that inhibiting FN-PDI activity with bacitracin would disrupt excessive FN-matrix assembly by cultured HMCs grown under high glucose conditions. METHODS The effect of bacitracin on FN-PDI activity was tested using an RNase-refolding assay. High glucose cultures of HMC were labeled with (3)H-leucine, with and without bacitracin, and (3)H-FN immunoprecipitated from the medium and sequential extracts of cell layers to distinguish insoluble FN. FN transcription was assessed by reverse transcription-polymerase chain reaction (RT-PCR). Pericellular FN-matrix was examined by immunohistology. RESULTS Bacitracin inhibited the PDI activity of FN, with maximal inhibition at 1.0 mmol/L. Treatment of HMC cultures grown in high glucose with bacitracin brought about changes in the distribution of newly synthesized FN. With increasing concentrations of bacitracin there was a significant reduction in the level of FN present as an insoluble matrix of HMC cultures maintained in high glucose, and a corresponding increase in FN in medium. Decreases in FN matrix laid down by HMCs treated with different concentrations of bacitracin were seen by immunohistology. FN mRNA levels were unchanged. CONCLUSION PDI inhibition of FN reduces its association into an insoluble matrix and potentially provides a new approach to reduce excessive matrix deposition in DN.
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Affiliation(s)
- B S Weston
- Cell and Molecular Biology Section, Division of Biomedical Sciences, Imperial College School of Medicine, Sir Alexander Fleming Building, South Kensington, London SW7 2 AZ, England, UK.
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