Breaking the fibrinolytic speed limit with microwheel co-delivery of tissue plasminogen activator and plasminogen.

BACKGROUND: To reestablish blood flow in vessels occluded by clots, tissue plasminogen activator (tPA) can be used; however, its efficacy is limited by transport to and into a clot and by the depletion of its substrate, plasminogen. OBJECTIVES: To overcome these rate limitations, a platform was designed to co-deliver tPA and plasminogen based on microwheels (µwheels), wheel-like assemblies of superparamagnetic colloidal beads that roll along surfaces at high speeds. METHODS: The biochemical speed limit was determined by measuring fibrinolysis of plasma clots at varying concentrations of tPA (10-800 nM) and plasminogen (1-6 µM). Biotinylated magnetic mesoporous silica nanoparticles were synthesized and bound to streptavidin-coated superparamagnetic beads to make studded beads. Studded beads were loaded with plasminogen and tPA was immobilized on their surface. Plasminogen release and tPA activity were measured on the studded beads. Studded beads were assembled into µwheels with rotating magnetic fields and fibrinolysis of plasma clots was measured in a microfluidic device. RESULTS: The biochemical speed limit for plasma clots was ~15 µm/min. Plasminogen-loaded, tPA-immobilized µwheels lyse plasma clots at rates comparableto the biochemical speed limit. With the addition of a corkscrew motion, µwheels penetrate clots, thereby exceeding the biochemical speed limit (~20 µm/min) and achieving lysis rates 40-fold higher than 50 nM tPA. CONCLUSIONS: Co-delivery of an immobilized enzyme and its substrate via a microbot capable of mechanical work has the potential to target and rapidly lyse clots that are inaccessible by mechanical thrombectomy devices or recalcitrant to systemic tPA delivery.

Uso y Administración del rtPA (activador tisular del plasminógeno): cuidados de enfermería / Use and Administration of rtPA (tissue plasminogen activator): nursing care

Si bien el uso rtPA está indicado para diversas patologías como el tratamiento trombolítico en los infartos agudos de miocardio, el tromboembolismo pulmonar agudo con inestabilidad hemodinamica y el tratamiento trombolítico del accidente cerebrovascular isquémico agudo conforme a la disposición DI­2018-495-APN-ANMAT#MSYDS el uso del mismo en Argentina y conforme a consenso (consenso sobre accidente cerebrovascular isquémico agudo). La administración oportuna del rtPA, a pacientes apropiadamente seleccionados constituye el principal tratamiento de forma temprana en el ACV (1-8). Por lo que el rol que cumple enfermería es fundamental en la valoración de riesgos previa a la administración, preparación, administración del fármaco y valoración continua post administración del mismo[AU]

Although the use of rtPA is indicated for various pathologies such as thrombolytic treatment in acute myocardial infarctions, acute pulmonary thromboembolism with hemodynamic instability, and thrombolytic treatment of acute ischemic stroke according to the DI-2018-495-APN-ANMAT provision. #MSYDS the use of thesame in Argentina and accordingtoconsensus (consensus on accident cerebrovascular ischemico acute). Timely administration of rtPAto appropriately selected patients constitutes the main treat mentearly in stroke (1,8). Therefore, the role play edby nursingis fundamental in the risk ass essment prior to the administration, preparation, administration of the drug, and continuous post-administration assessment[AU]

Embora o uso de rtPA seja indicado para várias patologias, como tratamento trombolítico em infartos agudos do miocárdio, tromboembolismo pulmonar agudo com instabilidade hemodinâmica e tratamento trombolítico de acidente vascular cerebral isquêmico agudo de acordo com a disposição DI- 2018-495-APN-ANMAT. #MSYDS a uso do mesmona Argentina e de acordocom o consenso (consensus on accident cerebrovascular ischemico agute). A administração oportuna de rtPA a pacientes adequadamente selecionados constitui o principal tratamento no início do AVC (1,8). Por tanto, o papel da enfermagem é fundamental na avaliação do risco antes da administração, preparo, administração do medicamento e avaliação pós-administração contínua[AU]

Plasminogen improves lung lesions and hypoxemia in patients with COVID-19.

BACKGROUND: Lungs from patients with coronavirus disease 2019 (COVID-19) have shown typical signs of acute respiratory distress syndrome (ARDS), formation of hyaline membrane mainly composed of fibrin and 'ground-glass' opacity. Previously, we showed plasminogen itself is a key regulator in fibrin degradation, wound healing and infection. AIM: We aimed to investigate whether plasminogen can improve lung lesions and hypoxemia of COVID-19. DESIGN: Thirteen clinically moderate, severe or critical COVID-19 patients were treated with atomization inhalation of freeze-dried plasminogen. METHODS: Levels of their lung lesions, oxygen saturation and heart rates were compared before and after treatment by computed tomography scanning images and patient monitor. RESULTS: After plasminogen inhalation, conditions of lung lesions in five clinically moderate patients have quickly improved, shown as the decreased range and density of 'ground glass' opacity. Improvements of oxygen saturation were observed in six clinically severe patients. In the two patients with critical conditions, the oxygen levels have significantly increased from 79-82% to 91% just about 1 h after the first inhalation. In 8 of 13 patients, the heart rates had slowed down. For the five clinically moderate patients, the difference is even statistically significant. Furthermore, a general relief of chest tightness was observed. CONCLUSION: Whereas it is reported that plasminogen is dramatically increased in adults with ARDS, this study suggests that additional plasminogen may be effective and efficient in treating lung lesions and hypoxemia during COVID-19 infections. Although further studies are needed, this study highlights a possible hope of efficiently combating this rapid epidemic emergency.

Treatment of Ligneous Conjunctivitis Using Topical Plasminogen Therapy in an 8-Week-Old Female Infant.

An 8-week-old female infant presented with bilateral eyelid swelling and conjunctival membranes. She was diagnosed as having ligneous conjunctivitis. The membranes were excised but recurred despite topical cyclosporine, heparin, fresh frozen plasma, and systemic fresh frozen plasma transfusions. Topical plasminogen prevented membrane recurrence and intravenous plasminogen therapy treated systemic manifestations of the disease. [J Pediatr Ophthalmol Strabismus. 2018;55:e30-e32.].

Plasminogen replacement therapy for the treatment of children and adults with congenital plasminogen deficiency.

Congenital plasminogen deficiency is caused by mutations in PLG, the gene coding for production of the zymogen plasminogen, and is an ultrarare disorder associated with abnormal accumulation or growth of fibrin-rich pseudomembranous lesions on mucous membranes. Left untreated, these lesions may impair organ function and impact quality of life. Plasminogen replacement therapy should provide an effective treatment of the manifestations of congenital plasminogen deficiency. An open-label phase 2/3 study of human Glu-plasminogen administered IV at 6.6 mg/kg every 2 to 4 days in 15 patients with congenital plasminogen deficiency is ongoing. Reported here are data on 14 patients who completed at least 12 weeks of treatment. The primary end point was an increase in trough plasminogen activity levels by at least an absolute 10% above baseline. The secondary end point was clinical success, defined as ≥50% improvement in lesion number/size or functionality impact from baseline. All patients achieved at least an absolute 10% increase in trough plasminogen activity above baseline. Clinical success was observed in all patients with clinically visible (conjunctiva and gingiva), nonvisible (nasopharynx, bronchus, colon, kidney, cervix, and vagina), and wound-healing manifestations of the disease. Therapeutic effects were rapid, as all but 2 lesions resolved or improved after 4 weeks of treatment. Human Glu-plasminogen was well tolerated in both children and adults. This study provides critical first evidence of the clinical utility of ongoing replacement therapy with human Glu-plasminogen for the treatment of children and adults with congenital plasminogen deficiency. This trial was registered at www.clinicaltrials.gov as #NCT02690714.

Tissue-type plasminogen activator contributes to remodeling of the rat ductus arteriosus.

AIMS: The ductus arteriosus (DA) closes after birth to adapt to the robust changes in hemodynamics, which require intimal thickening (IT) to occur. The smooth muscle cells of the DA have been reported to play important roles in IT formation. However, the roles of the endothelial cells (ECs) have not been fully investigated. We herein focused on tissue-type plasminogen activator (t-PA), which is a DA EC dominant gene, and investigated its contribution to IT formation in the DA. METHODS AND RESULTS: ECs from the DA and aorta were isolated from fetal rats using fluorescence-activated cell sorting. RT-PCR showed that the t-PA mRNA expression level was 2.7-fold higher in DA ECs than in aortic ECs from full-term rat fetuses (gestational day 21). A strong immunoreaction for t-PA was detected in pre-term and full-term rat DA ECs. t-PA-mediated plasminogen-plasmin conversion activates gelatinase matrix metalloproteinases (MMPs). Gelatin zymography revealed that plasminogen supplementation significantly promoted activation of the elastolytic enzyme MMP-2 in rat DA ECs. In situ zymography demonstrated that marked gelatinase activity was observed at the site of disruption in the internal elastic laminae (IEL) in full-term rat DA. In a three-dimensional vascular model, EC-mediated plasminogen-plasmin conversion augmented the IEL disruption. In vivo administration of plasminogen to pre-term rat fetuses (gestational day 19), in which IT is poorly formed, promoted IEL disruption accompanied by gelatinase activation and enhanced IT formation in the DA. Additionally, experiments using five human DA tissues demonstrated that the t-PA expression level was 3.7-fold higher in the IT area than in the tunica media. t-PA protein expression and gelatinase activity were also detected in the IT area of the human DAs. CONCLUSION: t-PA expressed in ECs may help to form IT of the DA via activation of MMP-2 and disruption of IEL.

A novel embryo culture media supplement that improves pregnancy rates in mice.

The preimplantation embryo in vivo is exposed to numerous growth factors in the female reproductive tract, which are not recapitulated in embryo culture media in vitro The IGF2 and plasminogen activator systems facilitate blastocyst development. We hypothesized that the addition of IGF2 in combination with urokinase plasminogen activator (uPA) and plasminogen could improve rates of blastocyst hatching and implantation in mice. B6BcF1 and CBAB6F2 mouse embryos were divided into one of four supplemented culture media treatment groups: (1) control (media only); (2) 12.5 nM IGF2; (3) 10 µg/mL uPA and 5 µg/mL plasminogen; or (4) a combination of IGF2, uPA and plasminogen treatments. Embryo development to blastocyst stage and hatching were assessed before transfer to pseudopregnant recipient females and implantation, pregnancy rates and postnatal growth were assessed. After 90.5 h of culture, IGF2 + U + P treatment increased the percentage of B6BcF1 embryos that were hatching/hatched and percentage developing to blastocyst stage compared with controls (P < 0.02). Following B6BcF1 embryo transfer, IGF2 + U + P treatment increased implantation sites at day 8 of pregnancy compared with controls (P < 0.05). Replication in the CBAB6F2 mouse strain showed significant improvements in pregnancy rates at days 8 and 18 but not in blastocyst development. No adverse effects were seen on gestational age, litter size or birthweight, or the reproductive capacity of offspring of IGF2 + U + P treated embryos. For embryos susceptible to detrimental effects of in vitro culture, IGF2, uPA and plasminogen supplementation of culture media can improve pregnancy success, but the effect of treatment is dependent on the mouse strain.

Plasminogen deficiency.

Plasminogen plays an important role in fibrinolysis as well as wound healing, cell migration, tissue modeling and angiogenesis. Congenital plasminogen deficiency is a rare autosomal recessive disorder that leads to the development of thick, wood-like pseudomembranes on mucosal surfaces, mostly seen in conjunctivas named as ''ligneous conjunctivitis''. Local conjunctival use of fresh frozen plazma (FFP) in combination with other eye medications such as cyclosporin and artificial tear drops may relieve the symptoms. Topical treatment with plasminogen eye drops is the most promising treatment that is not yet available in Turkey.

Topical Plasminogen as Adjunctive Treatment in Recurrent Ligneous Conjunctivitis.

Ligneous conjunctivitis is a rare, autosomal recessive, membranous conjunctivitis characterized by a deficiency in type 1 plasminogen. The absence of normal plasmin activity results in the formation of fibrin-rich, membranous material that typically manifests on the palpebral conjunctiva. Surgical treatment often causes irritation of the conjunctiva and accelerated recurrence of pseudomembranes. In this interventional case report, the authors document the results of treatment with topical plasminogen following conjunctival pseudomembrane excision in a 32-year-old woman. The patient underwent pseudomembrane excision in the OS followed immediately by hourly topical application of plasminogen eye drops. The plasminogen was prepared from pooled human plasma purchased under Food and Drug Administration approval from DiaPharma. Follow-up evaluation at 1 week, 1 month, and 5 months showed no evidence of recurrent pseudomembranous change. Adjunctive topical plasminogen application appears to be an effective and safe method of controlling pseudomembrane recurrence in patients with ligneous conjunctivitis.

Novel plasminogen and hyaluronate sodium eye drop formulation for a patient with ligneous conjunctivitis.

PURPOSE: The development, analysis, and first clinical use of a novel eye drop formulation of plasminogen and hyaluronate sodium for the treatment of a patient with ligneous conjunctivitis (LC) are described. SUMMARY: LC is a chronic inflammatory disorder of the eye that can in rare cases lead to corneal involvement and subsequent blindness. Topically administered plasminogen is an effective treatment for LC; however, the lack of a specific and validated formulation of plasminogen for topical treatment can constitute a gap in the quality of care. A novel formulation of plasminogen and hyaluronate sodium for the treatment of LC was developed by combining commercially available products. Through a series of tests, including microbiological, viscosity, and pH analyses, the novel eye drop formulation was demonstrated to have constant activity (3.3 IU/mL or greater), to be microbiologically stable (i.e., sterile), and to be safe enough for daily administration. The first clinical application of the novel eye drop formulation was in the case of a nine-year-old girl with LC affecting both eyes. Initially, the girl's parents administered two drops every three hours to the left eye each day while the girl was awake. On examination after 30 days of daily use of the eye drop formulation, the patient was found to have a clear cornea and no membrane development on the conjunctiva; the formulation was subsequently administered in both eyes, with positive results. CONCLUSION: A new formulation of plasminogen plus hyaluronate sodium was developed, tested, and used successfully in a girl with LC.

Beyond hemostasis: the challenge of treating plasminogen deficiency. A report of three cases.

Congenital plasminogen deficiency is a rare autosomal recessive disorder, characterized by chronic mucosal membranous lesions. Although the most common clinical manifestation is eye involvement as ligneous conjunctivitis, extra-ocular lesions affecting other mucosal surfaces indicates a systemic disease. In this report we describe two cases with atypical extra-ocular involvement that includes pericarditis and recurrent hematocolpos, and one with paradoxical correlation between ocular lesions and plasminogen levels. In ligneous conjunctivitis, although different treatment strategies have been tried with mild success, the only effective therapy is topical or systemic plasminogen concentrates that are not commercially available. Unfortunately there is not either effective management for cases with multisystemic disease. Hence, treatment for plasminogen deficiency is still a challenge and the variability of the clinical spectrum in this pathology makes necessary a multidisciplinary approach.

Conjunctival instillation of plasminogen eliminates ocular lesion in B6.129P2-Plg(tm1Jld) transgenic mice, a model of ligneous conjunctivitis.

Ligneous conjunctivitis is a severe and rare chronic "idiopathic membraneous" conjunctivitis, characterized by the formation of pseudomembranes mostly on the palpebral surfaces that progressively replace the normal mucosa. Evidence has been provided that ligneous conjunctivitis is caused by a severe systemic plasminogen deficiency with decreased plasminogen antigen and decreased plasminogen functional activities. Objective of the present study is to verify the hypothesis that a topical eye application of plasminogen is able to ameliorate the consequences of this disease. Here we report the results of pre-clinical studies performed to investigate the therapeutic effectiveness of an eye-drop plasminogen preparation in B6.129P2-Plg(tm1Jld) transgenic mice, a model of ligneous conjunctivitis. The entity of protection mediated by plasminogen was evaluated by measuring the extent of the eye lesion by means of a computerized system and dedicated software. The results of the present study clearly showed that the administration for six times a day of plasminogen eye-drop solution in the lesioned eye of animals knock-out for plasminogen gene and developing ligneous conjunctivitis caused a dose and time related reduction of the extent of the ocular lesion. These findings may pave the road for the pharmacological treatment of the ocular lesion associated to the ligneous conjunctivitis that at the present is surgically treated by removing the pseudomembranes generated on the eye.

Plasminogen is a key proinflammatory regulator that accelerates the healing of acute and diabetic wounds.

Despite decades of research on wound healing, effective biologic agents for the treatment of chronic wounds, especially diabetic wounds, are still lacking. In the present study, we report that the inert plasma protein plasminogen (plg) acts as a key regulatory molecule that potentiates wound healing in mice. Early in the healing process, plg bound to inflammatory cells is transported to the wound area, where the level of plg is increased locally, leading to the induction of cytokines and intracellular signaling events and to a potentiation of the early inflammatory response. Systemic administration of additional plg not only accelerates the healing of acute burn wounds in wild-type mice, but also improves the healing of chronic diabetic wounds in a mouse model of diabetes. Our results suggest that the administration of plg may be a novel therapeutic strategy to treat many different types of wounds, especially chronic wounds such as those caused by diabetes.

Anti-inflammatory and antiangiogenic effects of nanoparticle-mediated delivery of a natural angiogenic inhibitor.

PURPOSE: The purpose of this study was to evaluate the inhibitory effects of the nanoparticle-mediated delivery of plasminogen kringle 5 (K5) on choroidal neovascularization (CNV) and retinal inflammation. METHODS: CNV was induced by laser in adult rats. Nanoparticles with an expression plasmid of K5 (K5-NP) were injected into the vitreous. K5 expression was detected by immunohistochemistry. The CNV area was measured after fluorescein angiography. Retinal vascular permeability was quantified with Evans blue as a tracer. Expression of vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, and intercellular adhesion molecule (ICAM)-1 was measured by Western blot analysis or ELISA and real-time RT-PCR. RESULTS: Intense K5 expression was detected in the retina 2 weeks after the injection of K5-NP. Areas of CNV were significantly decreased in the K5-NP treatment group compared with that in the control-NP group. The K5-NP injection also significantly reduced vascular permeability. The expression of VEGF was downregulated by K5-NP at both the protein and mRNA levels. Moreover, K5-NP also inhibited expression of TNF-α and ICAM-1. Similarly, K5-NP decreased retinal levels of total ß-catenin. In cultured cells, K5-NP suppressed hypoxia-induced secretion of MCP-1 and TNF-α. CONCLUSIONS: K5 has a novel anti-inflammatory activity. K5-NP mediates a sustained inhibitory effect on CNV and thus has therapeutic potential for age-related macular degeneration.

Human plasminogen kringle 1-5 reduces atherosclerosis and neointima formation in mice by suppressing the inflammatory signaling pathway.

BACKGROUND: Activation of vascular endothelial cells plays an important role in atherogenesis and plaque instability. Recent research has demonstrated that late-stage inhibition of plaque angiogenesis by angiostatin (kringle 1-4) reduces macrophage accumulation and slows the progression of advanced atherosclerosis. Kringle 1-5 (K(1-5)) is a variant of angiostatin that contains the first five kringle domains of plasminogen. OBJECTIVE: To investigate whether K(1-5) has an inhibitory effect on early-stage atherosclerosis, using the apolipoprotein E (ApoE)-deficient mouse model and a carotid artery ligation model. METHODS: ApoE-deficient mice received K(1-5) treatment for 4 weeks, and the severity of aortic atherosclerosis was measured. In the ligation model, the left common carotid arteries of C57BL/6 mice were ligated near the carotid bifurcation, and the mice received K(1-5) for 4 weeks. Human umbilical vein endothelial cells were pretreated with K(1-5) before tumor necrosis factor-alpha (TNF-alpha) treatment to explore the anti-inflammatory effect of K(1-5). RESULTS: The areas of the lesion in the aortas of ApoE-deficient mice that received K(1-5) treatment were notably decreased, and the formation of carotid neointima in the C57BL/6 mice was decreased by treatment with K(1-5). Expression of TNF-alpha-induced intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 was inhibited by K(1-5) treatment, possibly via downregulation of translocation of nuclear factor-kappaB and expression of reactive oxygen species. CONCLUSIONS: K(1-5) reduced atherosclerosis and neointima formation in mice, possibly through inhibition of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression in endothelial cells.

Asociación entre el polimorfismo 4G/5G en el gen del inhibidor del activador del plasminógeno-1 (PAI-1) y el infarto agudo de miocardio con elevación del ST en pacientes jóvenes / Association of the plasminogen activator inhibitor-1 gene 4G/5G polymorphism with ST elevation acute myocardial infarction in young patients

Introducción y objetivos. Determinar la participación del polimorfismo 4G/5G en el gen del inhibidor del activador del plasminógeno tipo 1 (PAI-1) en pacientes con infarto agudo de miocardio con elevación del segmento ST y edad ≤ 45 años y su influencia en la regulación de la concentración plasmática de PAI-1. Métodos. En un estudio de casos y controles se incluyó, entre enero de 2006 y marzo de 2007, a 127 pacientes consecutivos con diagnóstico de infarto agudo de miocardio con elevación del segmento ST ingresados a la unidad de cuidados intensivos cardiovasculares y 127 controles. Se realizó genotipificación del polimorfismo 4G/5G mediante técnica de reacción en cadena de la polimerasa-polimorfismos en la longitud del fragmento de restricción, y la determinación de la concentración plasmática de PAI-1. Todos los pacientes firmaron consentimiento informado. Resultados. Se identificó una diferencia con significación estadística en la distribución genotípica entre los grupos (p < 0,002). La frecuencia del alelo 4G fue mayor en el grupo de estudio (p = 0,032). Se asociaron en forma independiente al infarto agudo de miocardio con elevación del segmento ST el alelo 4G (4G/4G + 4G/5G) (odds ratio [OR] = 2,29; intervalo de confianza [IC] del 95%, 1,12-4,68; p = 0,022), el tabaquismo (OR = 23,23; IC del 95%, 8,92-60,47; p < 0,001), el antecedente familiar de enfermedad cardiovascular (OR = 4,66; IC del 95%, 2,06-10,52; p < 0,001) y la hipertensión arterial (OR = 5,42; IC del 95%, 1,67-17,56; p = 0,005). Las concentraciones plasmáticas de PAI-1 fueron mayores en los homocigotos 4G (p < 0,001). Conclusiones. Estos resultados indican que el alelo 4G es un factor independiente de riesgo de infarto agudo de miocardio en pacientes jóvenes, al igual que el tabaquismo, la hipertensión arterial y los antecedentes hereditarios familiares de enfermedad cardiovascular (AU)

Introduction and objectives. To investigate the role of the 4G/5G polymorphism in the plasminogen activator inhibitor-1 (PAI-1) gene in patients with ST elevation myocardial infarction (STEMI) aged ≤45 years and its influence on regulation of the plasma PAI-1 concentration. Methods. This case-control study included 127 consecutive patients aged ≤45 years with a diagnosis of STEMI who were admitted to a cardiovascular intensive care unit and 127 controls recruited between January 2006 and March 2007. Participants were genotyped for the 4G/5G polymorphism using the polymerase chain reaction and restriction fragment length polymorphism analysis, and their plasma PAI-1 concentrations were measured. Informed consent was obtained from all participants. Results. There was a significant difference in genotype distribution between the 2 groups (P < .002). The 4G allele occurred more frequently in the patient group (P=.032). In addition, there were significant independent associations between STEMI and the 4G allele (ie, 4G/4G plus 4G/5G; odds ratio [OR] =2.29; 95% confidence interval [CI], 1.12-4.68; P=.022), smoking (OR=23.23; 95% CI, 8.92-60.47; P < .001), a family history of cardiovascular disease (OR=4.66; 95% CI, 2.06-10.52; P=.001) and hypertension (OR=5.42; 95% CI, 1.67-17.56; P=.005). The plasma PAI-1 concentration was higher in individuals who were homozygous for the 4G allele (P < .001). Conclusions. The study findings indicate that the 4G allele is an independent risk factor for acute myocardial infarction in young patients, as are smoking, hypertension, and a family history of inherited cardiovascular disease (AU)

Trombolisis intravenosa con rtPA en el Stroke Isquémico Agudo. Eficacia y seguridad del programa instalado en el Hospital Universitario de la Fundación Favaloro / Intravenous thrombolysis with recombinant tissue plasminogen activator in the acute ischemic stroke

The study of the National Institute of Neurological Disorders and Stroke (NINDS) proved that the use of the recombinant tissue plasminogen activator (rtPA) within the first 3 hours since the beginning of the symptomatology of the acute ischemis stroke (AIS) is as well safe as effective...These preliminary data reported in our study show that a strict protocol of thrombolysis IV with rtPA in AIS is feasible to be carried on with good results in a high complexity Center.

Plasminogen N-terminal activation peptide modulates the activity of angiostatin-related peptides on endothelial cell proliferation and migration.

Angiostatin, a potent inhibitor of angiogenesis, is derived from the fibrinolytic proenzyme, plasminogen, by enzymatic processing. Plasminogen N-terminal activation peptide (PAP) is one of the products concomitantly released aside from angiostatin (kringles 1-4) and mini-plasminogen (kringle 5 plus the catalytic domain) when plasminogen is processed. To determine whether PAP alone or together with the angiostatin-related peptides derived from the processing of plasminogen modulate the proliferation and motility of endothelial cells, we have generated a recombinant PAP and used it to study its effects on endothelial cells in the presence and absence of the angiostatin-related peptides. Our results showed that PAP alone slightly increased the migration but not the proliferation of endothelial cells. However, in the presence of the angiostatin-related peptides, PAP attenuated the inhibitory activity of the angiostatin-related peptides on the proliferation and migration of endothelial cells. The inhibitory effect of PAP on the angiostatin-related peptides could be due to its binding to the kringle domains of the latter peptides.