title: Fibrinogen nitrotyrosination after ischemic stroke impairs thrombolysis and promotes neuronal death.
abstract: Ischemic stroke is an acute vascular event that compromises neuronal viability, and identification of the pathophysiological mechanisms is critical for its correct management. Ischemia produces increased nitric oxide synthesis to recover blood flow but also induces a free radical burst. Nitric oxide and superoxide anion react to generate peroxynitrite that nitrates tyrosines. We found that fibrinogen nitrotyrosination was detected in plasma after the initiation of ischemic stroke in human patients. Electron microscopy and protein intrinsic fluorescence showed that in vitro nitrotyrosination of fibrinogen affected its structure. Thromboelastography showed that initially fibrinogen nitrotyrosination retarded clot formation but later made the clot more resistant to fibrinolysis. This result was independent of any effect on thrombin production. Immunofluorescence analysis of affected human brain areas also showed that both fibrinogen and nitrotyrosinated fibrinogen spread into the brain parenchyma after ischemic stroke. Therefore, we assayed the toxicity of fibrinogen and nitrotyrosinated fibrinogen in a human neuroblastoma cell line. For that purpose we measured the activity of caspase-3, a key enzyme in the apoptotic pathway, and cell survival. We found that nitrotyrosinated fibrinogen induced higher activation of caspase 3. Accordingly, cell survival assays showed a more neurotoxic effect of nitrotyrosinated fibrinogen at all concentrations tested. In summary, nitrotyrosinated fibrinogen would be of pathophysiological interest in ischemic stroke due to both its impact on hemostasis - it impairs thrombolysis, the main target in stroke treatments - and its neurotoxicity that would contribute to the death of the brain tissue surrounding the infarcted area.
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain.
authors.forename: Gerard
authors.initials: G
authors.lastname: Ill-Raga
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain.
authors.forename: Ernest
authors.initials: E
authors.lastname: Palomer
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Ramos-Fernández
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain.
authors.forename: Francesc X
authors.initials: FX
authors.lastname: Guix
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain.
authors.forename: Mònica
authors.initials: M
authors.lastname: Bosch-Morató
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain.
authors.forename: Biuse
authors.initials: B
authors.lastname: Guivernau
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Tajes
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain.
authors.forename: Victòria
authors.initials: V
authors.lastname: Valls-Comamala
authors.affiliation: Servei de Neurologia, Hospital del Mar-IMIM-Parc de Salut Mar, Barcelona, Catalonia 08003, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Jiménez-Conde
authors.affiliation: Servei de Neurologia, Hospital del Mar-IMIM-Parc de Salut Mar, Barcelona, Catalonia 08003, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: Ois
authors.affiliation: Institut d'Investigacions Biomèdiques de Barcelona (IIBB)-Consejo Superior de Investigaciones Científicas (CSIC), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia 08036, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Pérez-Asensio
authors.affiliation: Laboratory of Neurobiometals, Department of Physiology, University of Concepción, 4089100, Chile.
authors.forename: Mario
authors.initials: M
authors.lastname: Reyes-Navarro
authors.affiliation: Department of Hemotherapy and Hemostasis, Hospital Clinic, Biomedical Diagnosis Centre, Institute of Biomedical Research August Pi i Sunyer, University of Barcelona, Catalonia 08036, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Caballo
authors.affiliation: Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Parc de Salut Mar, Barcelona, Catalonia 08003, Spain.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gil-Gómez
authors.affiliation: Department of Hemotherapy and Hemostasis, Hospital Clinic, Biomedical Diagnosis Centre, Institute of Biomedical Research August Pi i Sunyer, University of Barcelona, Catalonia 08036, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Lopez-Vilchez
authors.affiliation: Department of Hemotherapy and Hemostasis, Hospital Clinic, Biomedical Diagnosis Centre, Institute of Biomedical Research August Pi i Sunyer, University of Barcelona, Catalonia 08036, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Galan
authors.affiliation: Servei d'Anatomia Patològica, Hospital del Mar-IMIM-Parc de Salut Mar, Barcelona, Catalonia 08003, Spain.
authors.forename: Francesc
authors.initials: F
authors.lastname: Alameda
authors.affiliation: Department of Hemotherapy and Hemostasis, Hospital Clinic, Biomedical Diagnosis Centre, Institute of Biomedical Research August Pi i Sunyer, University of Barcelona, Catalonia 08036, Spain.
authors.forename: Gines
authors.initials: G
authors.lastname: Escolar
authors.affiliation: Laboratory of Neurobiometals, Department of Physiology, University of Concepción, 4089100, Chile; Oxidation Biology Laboratory, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 3010, Australia.
authors.forename: Carlos
authors.initials: C
authors.lastname: Opazo
authors.affiliation: Institut d'Investigacions Biomèdiques de Barcelona (IIBB)-Consejo Superior de Investigaciones Científicas (CSIC), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia 08036, Spain.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Planas
authors.affiliation: Servei de Neurologia, Hospital del Mar-IMIM-Parc de Salut Mar, Barcelona, Catalonia 08003, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Roquer
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Valverde
authors.affiliation: Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, Catalonia 08003, Spain. Electronic address: paco.munoz@upf.edu.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Muñoz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D017209:Apoptosis; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D005342:Fibrinolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020521:Stroke / Q000378:metabolism* / Q000473:pathology; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: C002744:3-nitrotyrosine; D014443:Tyrosine; D005340:Fibrinogen; C505407:CASP3 protein, human; C505410:Casp3 protein, rat; D053148:Caspase 3
keywords: Apoptosis; Fibrinogen; Ischemic stroke; Nitric oxide; Peroxynitrite