Plasminogen: Structure, Activation, and Regulation

TheobservationthatabloodclotspontaneouslydissolveswasfirstdescribedbyDenys in1889. Subsequently,thebloodclottingsystemwasshowntobeinvolvedintumor growth. Forexample,asearlyas1925,Fisherreportedthataviantissueexplantstrans- formedtomalignancybyvirusesgeneratedhighlevelsoffibrinolyticactivityundercon- ditionsinwhichculturesofnormalcellsdidnot. In1958,theconceptthatan equilibriumexistedbetweenthetendencyofbloodtoclotandtoremainfluidwaspro- posedbyAstrup. Atthattime,itwasbelievedthatthishemostaticbalancewasexplained bytheabilityofpolymerizingfibrintoorchestrateitsownclearancebystimulatingfib- rinolyticactivity. Sincethesepioneeringstudies,considerableinformationhasaccumu- latedthathasdefinedthecomponentsofthecoagulationandfibrinolyticsystemsand howtheyareinvolvedinphysiologicalandpathophysiologicalprocesses. Plasminogen: Structure, activation, and regulationfocusesonthebasicprinciplesandrecentdevelop- mentsintheplasminogen/plasminresearchfieldandhowtheseresultsprovideacon- ceptualframeworkforanunderstandingofthephysiologicalroleofplasminogenin healthanddisease. Theenzymaticcascadetriggeredbyactivationofplasminogenhasbeenimplicated inavarietyofnormalandpathologicaleventssuchasfibrinolysis,woundhealing,tis- sueremodeling,embryogenesis,angiogenesis,andtheinvasionandmetastasisoftumor cells. Thisimpressivelistofphysiologicalfunctionsforplasminogenreinforcesthewide diversityofrolesthatplasminogenplaysinvariousphysiologicalprocesses. Productive plasmingenerationrequirestheassemblyofbothplasminogenactivatorsandplasmino- genonasolidsupportsuchasthefibrinpolymerorthecellsurface. Theregulationof plasminproductioninvolvesacomplexinterplaybetweentheseplasminogenactivators, plasminogenactivatorinhibitors,andplasmininhibitors. Clearly,theexplosivegrowth inthisresearchfieldandthemanyexcitingdiscoveriessuggeststhattheresearchefforts inthenextdecadewillrevealthemechanismsbywhichthecomponentsoftheplas- minogensysteminteractandregulatebothplasminactivationandfunctionatacellular level. Plasminogen: Structure, activation, and regulationisdividedintotwosections. Thefirstsectiondealswiththestructureandregulationofplasminogen. Thechapters inthissectionrangefromdiscussionsofthestructureofplasminogenandtheregulation oftheplasminogengenetodiscussionsofthestructureandregulationofplasminogen activatorsandplasminogenactivatorinhibitors. Alsoexaminedistherelativelynewdata concerningthegenerationofanti-angiogenicmoleculesfromplasminogen. Thesecond sectiondealswiththephysiologicalandpathophysiologicalrolesofplasminogenaswell astheconsequencesofplasminogengeneknockout. Discussionsinthissectioninclude examinationoftheroleofplasminogeninhematopoieticmalignancies,tumorcell progression,angiogenesis,mammaryglandinvolution,woundhealing,andbone readsorption. xi xii Preface Inclosing,Iwouldliketothankmyadministrativeassistant,Ms. ViSommerfeld,for herinvaluableassistanceandtimelesseffortswiththeorganizationandeditingofthebook. Lastly,Iwouldliketoacknowledgetheeffortsoftheauthorsoftheindividualchapters, whoareauthorities inthisfield,foragreeingtotaketimefrombusyschedulestoprovide thesechaptersinatimelyfashion. DavidMortonWaisman Contents Part I. Plasminogen: Structure and Regulation 1. Human Plasminogen: Structure, Activation, and Function FrancisJ. Castellino and Victoria A. Ploplis 1. Introduction 3 2. StructureofHumanPlasminogen...3 2. 1. PrimaryProteinStructure...3 2. 2. GeneOrganization 5 3. ActivationofHumanPlasminogen...6 3. 1. ActivationbyPhysiologicalActivators 7 3. 1. 1. Urokinase-typePlasminogenActivator...7 3. 1. 2. Tissue-typePlasminogenActivator...8 3. 2. ActivationbyBacterial-derivedPlasminogenActivators...9 3. 2. 1. Streptokinase 9 3. 2. 2. Staphylokinase...9 4. TargetsforPlasminActivity...9 5. DysplasminogenemiasandPhenotypicManifestations 10 6. Conclusions 11 References...11 2. Plasminogen Activators: Structure and Function Vincent Ellis 1. Introduction ...19 2. SerineProteases...20 3. UrokinasePlasminogenActivator,uPA...21 3. 1. SerineProteaseDomain 22 3. 2. N-terminalDomains...24 3. 2. 1. KRModule 24 3. 2. 2. EGModule 24 4. MechanismsRegulatinguPAFunction...25 4. 1. ZymogenActivation...25 4. 2. ZymogenActivity...26 4. 3. ReciprocalZymogenActivation 27 4. 4. uPARStimulationofPlasminogenActivation...27 4. 4. 1. uPAandtheTemplateMechanism 28 4. 4. 2. PlasminogenandtheTemplateMechanism 29 4. 5. AvianuPA,aSpecialCase? 30 xiii xiv Contents 5. TissuePlasminogenActivator,tPA...30 5. 1. SerineProteaseDomain 31 5. 2. N-terminalDomains ,...33 5. 2. 1. KRModules ,. . ,. . ,...33 5. 2. 2. F1-EGSupermodule 33 6.

I. Plasminogen: Structure and Regulation.- 1. Human Plasminogen: Structure, Activation, and Function.- 1. Introduction.- 2. Structure of Human Plasminogen.- 2.1. Primary Protein Structure.- 2.2. Gene Organization.- 3. Activation of Human Plasminogen.- 3.1. Activation by Physiological Activators.- 3.1.1. Urokinase-type Plasminogen Activator.- 3.1.2. Tissue-type Plasminogen Activator.- 3.2. Activation by Bacterial-derived Plasminogen Activators.- 3.2.1. Streptokinase.- 3.2.2. Staphylokinase.- 4. Targets for Plasmin Activity.- 5. Dysplasminogenemias and Phenotypic Manifestations.- 6. Conclusions.- References.- 2. Plasminogen Activators: Structure and Function.- 1. Introduction.- 2. Serine Proteases.- 3. Urokinase Plasminogen Activator, uPA.- 3.1. Serine Protease Domain.- 3.2. N-terminal Domains.- 3.2.1. KR Module.- 3.2.2. EG Module.- 4. Mechanisms Regulating uPA Function.- 4.1. Zymogen Activation.- 4.2. Zymogen Activity.- 4.3. Reciprocal Zymogen Activation.- 4.4. uPAR Stimulation of Plasminogen Activation.- 4.4.1. uPA and the Template Mechanism.- 4.4.2. Plasminogen and the Template Mechanism.- 4.5. Avian uPA, a Special Case?.- 5. Tissue Plasminogen Activator, tPA.- 5.1. Serine Protease Domain.- 5.2. N-terminal Domains.- 5.2.1. KR Modules.- 5.2.2. Fl-EG Supermodule.- 6. Mechanisms Regulating tPA Function.- 6.1. Zymogenicity.- 6.2. Fibrin Stimulation of Plasminogen Activation.- 6.2.1. tPA/fibrin Interaction.- 6.2.2. Vampire Bat Plasminogen Activator.- 6.3. Cellular Mechanisms Regulating tPA Activity.- 6.3.1. Endothelial Cells.- 6.3.2. Vascular Smooth Muscle Cells.- 6.3.3. Prion Protein.- 7. Concluding Remarks.- References.- 3. Plasminogen Activators Inhibitors.- 1. Plasminogen Activator Inhibitor-1.- 1.1. Natural and Recombinant PAI-1.- 1.2. Distinct Conformations of PAI-1.- 1.3. Target Specificity of PAI-1.- 1.4. PAI-1 in Patho-Physiological Processes.- 1.4.1. PAI-1 and Cardiovascular Disease.- 1.4.2. PAI-1 and Cancer.- 1.5. PAI-1 Inhibitors and their Binding Sites.- 2. Plasminogen Activator Inhibitor-2.- 2.1. Function of PAI-2.- 2.2. PAI-2 Polymerization.- 3. Plasminogen Activator Inhibitor-3.- 3.1. Target Specificity of PAJ-3.- 3.2. Physiological Role of PAI-3.- References.- 4. Regulation of Plasminogen Gene Expression.- 1. Introduction.- 2. The Plasminogen Gene.- 2.1. Mechanisms of Constitutive Regulation of Plasminogen Gene Expression.- 2.2. Plasminogen Distribution in Tissues.- 3. Regulation of Plasminogen Gene Expression in vitro and in vivo.- 3.1. Interleukin-6.- 3.2. Glucocorticoids.- 3.3. LPS.- 3.4. Tumor Necrosis Factor-? (TNF-?) and Transforming Growth Factor-? (TGF-?).- 3.5. Interleukin-1.- 3.6. Kainic Acid.- 4. Conclusions.- Acknowledgments.- References.- 5. Plasminogen Receptors.- 1. Introduction to Cellular Plasminogen Activation.- 2. Mechanism of Cellular Plasminogen Binding.- 2.1. History.- 2.2. Kinetics of Plasminogen Binding.- 2.3. Binding of Plasminogen Isoforms.- 3. Plasminogen Receptors as Regulators of Plasmin Activity.- 4. Modulation of Receptor Expression.- 4.1. Plasminogen Receptor Expression on Platelets.- 4.2. Plasminogen Receptor Expression on Endothelial Cells.- 4.3. Plasminogen Receptor Expression on Peripheral Blood Cells.- 4.4. Plasminogen Receptor Expression on Tumor Cells.- 5. Candidate Plasminogen Receptors.- 6. Annexin II, P11, and Annexin II Heterotetramer as Candidate Plasminogen Receptors.- 7. Concluding Remarks.- References.- 6. The Role of Lys-Plasminogen in Cell-Mediated Plasmin Production.- 1. Introduction.- 2. Key Differences between Glu-Plasminogen and Lys-Plasminogen.- 3. Mechanisms by which Plasminogen Activation is Enhanced on the Cell Surface.- 3.1. Role of the Glu-Plasminogen to Lys-Plasminogen Conversion in Plasminogen Activation by t-PA on the Cell Surface.- 3.2. Role of the Glu-Plasminogen to Lys-Plasminogen Conversion in Plasminogen Activation by u-PA on the Cell Surface.- 3.3. Effect of Cells on Conversion of [D(646)E]Glu-Pg to [D(646)E]Lys-Pg by Exogenous Plasmin.- 4. Conclusions.- Acknowledgments.- References.- 7. Plasmin Reductase.- 1. Introduction.- 2. Identification of Plasmin Reductase Activity.- 3. Disulfide-Bonds Cleaved by Plasmin Reductase.- 4. Proteolysis of Reduced Plasmin.- 5. Plasmin Reductase is Phosphoglycerate Kinase.- 6. Structure/Function Aspects of Plasmin Reduction by Phosphoglycerate Kinase.- 7. Putative Mechanism of Action of Phosphoglycerate Kinase.- 8. Phosphoglycerate Kinase in Tumor Angiogenesis.- 9. Future Directions.- References.- 8. Mechanism of Angiostatin Formation from Plasminogen.- 1. Introduction.- 2. Identification of Plasminogen Fragment, A61, Produced by Plasmin Autoproteolysis.- 3. Characterization of A61, an Anti-Angiogenic Plasminogen Fragment.- 4. Identification of Cell-Generated Plasminogen Fragments.- 5. Characterization of p22, the Smallest Anti-Angiogenic Plasminogen Fragment Produced by Cultured Cells.- 6. Identification of Plasminogen Fragments Present in Sera.- 7. Annexin II Tetramer, a Putative Plasminogen Receptor.- 8. Plasmin Reductase Activity of Annexin II Tetramer.- 9. Mechanism of Action of Annexin II Tetramer on A61 Formation.- 10. Concluding Remarks.- Acknowledgment.- References.- II. Physiological Roles of Plasminogen.- 9. Lessons Learned from the Pig Deficient Mice (Plg—/—).- 1. Introduction.- 2. Development.- 2.1. Physical Development.- 2.2. Behavioral Development.- 3. Role of the Plg System in Stress.- 3.1. Alterations of the Plg System in Response to Stress.- 3.2. Grooming, a Stress-Induced Behavior is Increased in the Plg—/— Mice.- 3.3. Acoustic Startle Reflex, a Stress-Induced Behavior is Decreased in Plg—/— Mice.- 3.4. The Plg System in Neuroendocrine Tissues and Alterations in Plg—/— Mice.- 4. Role of the Plg System in Adipose Tissue Development.- 4.1. Role of the Plg System in Obesity.- 4.2. Plg and Plg System Components in Adipose Tissue.- 4.3. Adipose Tissue Development in Plg—/— Mice.- 4.4. Vascularization of Adipose Tissue.- 5. Summary.- References.- 10. Plasminogen-Directed Phenotypes in Mice.- 1. Introduction.- 2. Generation and Initial Characterization of Plasminogen-Deficient Mice (PG-/-).- 3. Challenge-Induced Phenotypes in Mice Deficient for Plasminogen.- 3.1. Pulmonary Clot Lysis.- 3.2. Responses to Vascular Injury.- 3.3. Pathogen Susceptibility and Inflammation.- 3.4. Glomerulonephritis.- 3.5. Rheumatoid Arthritis.- 3.6. Pulmonary Fibrosis.- 3.7. Wound Healing.- 3.8. Neuronal and Axonal Degeneration and Demyelination.- 3.9. Tumor Development, Metastatis, and Angiogenesis.- 4. Conclusion.- References.- 11. Role of the Plasminogen and MMP Systems in Wound Healing.- 1. Introduction.- 2. Plasminogen/Plasmin and MMP Systems.- 2.1. Plasminogen/Plasmin System.- 2.2. MMP System.- 2.3. Molecular Interactions Between the Plasminogen/Plasmin and MMP Systems.- 3. Arterial Restenosis.- 3.1. Role of the Plasminogen/Plasmin System in Neointima Formation.- 3.2. Role of the MMP System in Neointima Formation.- 4. Allograft Transplant Stenosis.- 5. Skin Wound Healing.- 6. Myocardial Ischemia.- 7. Summary.- References.- 12. Matrix Metalloproteinases and the Plasminogen System in Tumor Progression.- 1. Introduction.- 2. Matrix Metalloproteinases.- 2.1. MMP Classification and their Expression in Cancer.- 2.2. Substrate Specificity.- 2.3. Activation.- 3. Interactions Between MMPs and the Plasminogen System.- 3.1. Activation of proMMPs by Plasmin.- 3.2. Cleavage of Plasmin by MMPs.- 3.3. MMPs Degrade Plasmin Inhibitors.- 3.4. MMPs and Plasmin Degrade Several Common Proteins.- 4. Interaction between MMPs and the Plasminogen System in Tumor Invasion and Metastasis.- 4.1. Expression of MMPs and PA in Cancer.- 4.2. MMPs and Plasminogen Interactions in vitro.- 4.3. MMPs and Plasminogen Interaction in vivo.- 4.4. Conclusion and Directions.- 5. Interaction between MMPs and Plasminogen System in Angiogenesis.- 5.1. In vitro and in vivo Studies.- 5.2. Paradoxical Aspects.- 6. Relevance of these Studies in Human Cancer.- Acknowledgments.- References.- 13. Role of Plasminogen Activation in Hematopoietic Malignancies and in Normal Hematopoiesis.- 1. Introduction.- 2. Normal Hematopoiesis and its Control.- 3. Leukemia.- 3.1. Classification.- 3.2. Clinical Findings.- 4. Plasminogen Activation System in General.- 4.1. Structure and General Function of uPAR.- 4.2. Soluble uPAR (suPAR).- 5. Plasminogen Activation in Leukemia.- 5.1. Components of the PA System in Normal Blood Cells.- 5.2. Components of the PA System in Leukemia Cells.- 5.3. Soluble uPA and uPAR in Leukemia.- 5.4. Expression Patterns of uPAR Fragments in Leukemia Patients and in Healthy Controls.- 6. Clinical Impact of Plasminogen Activation in Leukemia.- 6.1. Plasminogen Activation System and Hemostasis.- 6.2. Cell Surface Plasminogen Activators and Urokinase Receptor: Diagnostic and Prognostic Tools in Leukemia?.- 6.3. suPAR as a Marker for Prognosis in Leukemia.- 7. Perspectives.- References.- 14. The Role of Plasminogen in Bone Remodeling.- 1. Osteoblasts and Bone Formation.- 2. Osteoclasts and Bone Resorption.- 3. Bone Remodeling.- 4. Regulation of the PA/Plasmin System in Bone Cells.- 4.1. Peptide Hormones and Cyclic AMP.- 4.2. Glucocorticoids and l,25(OH)2 Vitamin D3.- 4.3. Cytokines and Growth Factors.- 5. Potential Roles of the PA/Plasmin System in Bone.- 5.1. Bone Resorption.- 5.2. Studies in Genetically Manipulated Mice.- 5.3. Bone Formation.- References.- 15. Plasminogen Activators in CNS Physiology and Disease.- 1. Introduction.- 2. Expression and Function of Plasminogen Activators in the Normal CNS.- 2.1. Plasminogen Activators in Developing and Adult CNS.- 2.2. Role of Plasminogen Activators in Neuronal Migration, Plasticity, and Learning.- 2.2.1. Neuronal Migration.- 2.2.2. Synaptic Plasticity.- 3. Plasminogen Activators in CNS Pathologies.- 3.1. Excitotoxicity.- 3.2. Ischemic Stroke.- 3.3. Neurodegenerative Diseases.- 3.3.1. Alzheimer’s Disease.- 3.3.2. Creutzfeldt-Jakob Disease.- 3.4. Neuroinflammatory Diseases.- 3.5. CNS Malignancy.- 4. Conclusions and Future Perspectives.- 5. Acknowledgments.- References.- 16. Role of the Plasminogen Activator-Plasmin System in Angiogenesis.- 1. Introduction.- 2. Role of the PA-Plasmin System in Angiogenesis.- 2.1. uPA/uPAR Interactions are Required for Angiogenesis.- 2.2. PAI-1 is Required for Angiogenesis.- 2.3. Does tPA Play a Role in Angiogenesis?.- 2.4. MMP Requirement for Fibrinolysis During Angiogenesis.- 2.5. Angiostatin and other Angiostatic Derivatives of Plasminogen.- 3. Requirement for the PA-Plasmin Systems in Polyoma Virus Middle T Oncogene-induced Vascular Tumor Formation.- 4. Conclusions and Perspectives.- Acknowledgments.- References.