RESUMO
The main obstacle to biopharmaceutical delivery in therapeutic concentration into the brain for treating neurological disorders is the presence of the Blood-Brain Barrier (BBB). The physiological process of Receptor-Mediated Transcytosis (RMT) to transport cargo through the brain endothelial cells toward brain parenchyma has prompted researchers to search for non-natural ligands that can be used to transport drugs across the BBB. Conjugation of drugs to RMT ligands would be an effective strategy for its delivery to the central nervous system. An attractive approach to identify novel transcytosing ligands is the screening by phage display combinatorial libraries. The main technology strength lies in the large variety of exogenous peptides or proteins displayed on the phage's surface. Here, we provide a mini-review of phage display technology using in vitro and in vivo BBB models for the development of peptide-mediated drug delivery systems.
Assuntos
Bacteriófagos , Barreira Hematoencefálica , Transporte Biológico , Barreira Hematoencefálica/metabolismo , Sistemas de Liberação de Medicamentos , Células Endoteliais/metabolismo , Humanos , Peptídeos/metabolismo , TecnologiaRESUMO
Therapies aimed at enhancing cardiomyocyte survival following myocardial injury are urgently required. As GHRP6 [GH (growth hormone)-releasing peptide 6] has been shown to stimulate GH secretion and has beneficial cardiovascular effects, the aim of the present study was to determine whether GHRP6 administration reduces myocardial infarct size following acute coronary occlusion in vivo. Female Cuban Creole pigs were anaesthetized, monitored and instrumented to ensure a complete sudden left circumflex artery occlusion for 1 h, followed by a 72 h reperfusion/survival period. Animals were screened clinically before surgery and assigned randomly to receive either GHRP6 (400 microg/kg of body weight) or normal saline. Hearts were processed, and the area at risk and the infarct size were determined. CK-MB (creatine kinase MB) and CRP (C-reactive protein) levels and pathological Q-wave-affected leads were analysed and compared. Evaluation of the myocardial effect of GHRP6 also included quantitative histopathology, local IGF-I (insulin-growth factor-I) expression and oxidative stress markers. GHRP6 treatment did not have any influence on mortality during surgery associated with rhythm and conductance disturbances during ischaemia. Infarct mass and thickness were reduced by 78% and 50% respectively, by GHRP6 compared with saline (P<0.01). More than 50% of the GHRP6-treated pigs did not exhibit pathogological Q waves in any of the ECG leads. Quantitative histopathology and CK-MB and CRP serum levels confirmed the reduction in GHRP6-mediated necrosis (all P<0.05). Levels of oxidative stress markers suggested that GHRP6 prevented myocardial injury via a decrease in reactive oxygen species and by the preservation of antioxidant defence systems (all P<0.05). Myocardial IGF-I transcription was not amplified by GHRP6 treatment compared with the increase induced by the ischaemic episode in relation to expression in intact hearts (P<0.01). In conclusion, GHRP6 exhibits antioxidant effects which may partially contribute to reduce myocardial ischaemic damage.
Assuntos
Antioxidantes/uso terapêutico , Cardiotônicos/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Miócitos Cardíacos/efeitos dos fármacos , Oligopeptídeos/uso terapêutico , Animais , Arritmias Cardíacas/prevenção & controle , Proteína C-Reativa/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Creatina Quinase Forma MB/sangue , Modelos Animais de Doenças , Eletrocardiografia/efeitos dos fármacos , Feminino , Fator de Crescimento Insulin-Like I/metabolismo , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miocárdio/patologia , Miócitos Cardíacos/patologia , Necrose/prevenção & controle , Tamanho do Órgão/efeitos dos fármacos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , SuínosRESUMO
Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that is angiogenic in vitro and in vivo. Several studies report on gene transfer of VEGF121 to promote angiogenesis in the ischemic myocardium of animals and patients. We hypothesized that intramyocardial administration of naked plasmid DNA encoding VEGF121 could improve myocardial perfusion and function in a porcine model of myocardial ischemia. Yorkshire swine underwent thoracotomy and placement of an ameroid constrictor on the circumflex coronary artery. Four weeks later, pVEGF121 plasmid was administered into the ischemic myocardium. Four weeks after gene transfer, SPECT imaging demonstrated significant reduction in the ischemic area in pVEGF121-treated animals compared with controls. In the pVEGF121 group, most of the animals evolved from light ischemia to a normal perfusion. In contrast, control animals exhibited similar or impaired ischemic conditions. Our results indicate that intramyocardial gene transfer of VEGF121 as naked plasmid DNA results in significant improvement in myocardial perfusion and function.
Assuntos
Animais , Circulação Colateral , Circulação Colateral/genética , Fator A de Crescimento do Endotélio Vascular/farmacologia , Isquemia Miocárdica/terapia , Terapia Genética/métodos , Análise de Variância , Coração , Modelos Animais de Doenças , DNA , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/uso terapêutico , Técnicas de Transferência de Genes , Isquemia Miocárdica/fisiopatologia , Isquemia Miocárdica/genética , Plasmídeos/farmacologia , Revascularização Miocárdica/métodos , Suínos , Vasos CoronáriosRESUMO
Protein Kinase (casein kinase 2, CK2) is a serine-threonine kinase that is frequently dysregulated in many human tumors. Therefore we hypothesized that peptides capable of binding to the CK2 acidic domain may exhibit potential anticancer properties. By screening a random cyclic peptide phage display library, we have identified a novel peptide, P15, that abrogated CK2 phosphorylation by blocking the substrate in vitro. To verify its potential antineoplastic effect, P15 was fused to the cell-penetrating peptide derived from the HIV-Tat protein. Interestingly, P15-Tat induced apoptosis as evidenced by rapid caspase activation and cellular cytotoxicity in a variety of tumor cell lines. Furthermore, direct injection of P15-Tat into C57BL6 mice bearing day 7-established solid tumors, resulted in substantial regression of the tumor mass. Our findings describe a new proapoptotic cyclic peptide that blocks the CK2 phosphorylation and exhibits antitumor effect in vivo, indicating that the P15 peptide may potentially be used clinically to treat solid tumors or as an adjuvant for cancer therapy.
Assuntos
Apoptose/efeitos dos fármacos , Peptídeos Cíclicos/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Caseína Quinase II , Linhagem Celular Tumoral , Produtos do Gene tat/genética , Produtos do Gene tat/farmacocinética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Biblioteca de Peptídeos , Peptídeos Cíclicos/genética , Peptídeos Cíclicos/farmacocinética , Fosforilação/efeitos dos fármacos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacocinética , Proteínas Recombinantes de Fusão/farmacologiaRESUMO
Protein Kinase (casein kinase 2, CK2) is a serine-threonine kinase that is frequently dysregulated in many human tumors. Therefore we hypothesized that peptides capable of binding to the CK2 acidic domain may exhibit potential anticancer properties. By screening a random cyclic peptide phage display library, we have identified a novel peptide, P15, that abrogated CK2 phosphorylation by blocking the substrate in vitro. To verify its potential antineoplastic effect, P15 was fused to the cell-penetrating peptide derived from the HIV-Tat protein. Interestingly, P15-Tat induced apoptosis as evidenced by rapid caspase activation and cellular cytotoxicity in a variety of tumor cell lines. Furthermore, direct injection of P15-Tat into C57BL6 mice bearing day 7-established solid tumors, resulted in substantial regression of the tumor mass. Our findings describe a new proapoptotic cyclic peptide that blocks the CK2 phosphorylation and exhibits antitumor effect in vivo, indicating that the P15 peptide may potentially be used clinically to treat solid tumors or as an adjuvant for cancer therapy(AU)
Proteína quinasa (caseína kinasa 2, CK2) es una serina-treonina quinasa que es con frecuencia dysregulated en muchos tumores humanos. Por lo tanto, la hipótesis de que los péptidos capaces de unirse a los ácidos CK2 dominio pueden presentar posibles propiedades anticancerígenas. Por una selección aleatoria péptido cíclico fagos mostrar la biblioteca, hemos identificado un nuevo péptido, P15, que derogó CK2 bloqueando la fosforilación del sustrato in vitro. Para comprobar su potencial efecto antineoplásico, P15 fue fundida a la célula de penetración del péptido derivado de la proteína Tat del VIH. Curiosamente, P15 Tat-como lo demuestra la apoptosis inducida por la rápida activación de caspasas y la citotoxicidad celular en una variedad de líneas de células tumorales. Además, la inyección directa de Tat-P15 en ratones con C57BL6 día 7-establecido los tumores sólidos, dio lugar a la regresión de la masa tumoral. Nuestros resultados describen un nuevo péptido cíclico proapoptóticos que bloquea la fosforilación y exposiciones CK2 efecto antitumoral in vivo, indicando que el péptido P15 puedan ser utilizados clínicamente para el tratamiento de tumores sólidos o como terapia adyuvante para el cáncer
Assuntos
Animais , Camundongos , Apoptose , Peptídeos Cíclicos/genética , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/farmacocinética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Proteínas Recombinantes/farmacologiaRESUMO
En este trabajo se describe la técnica denominada Cosmix-Plexing que proporciona un modo novedoso de generar y utlilizar bibliotecas combinatorias de péptidos presentados en la superficie de fagos. Mediante la técnica de Cosmix-Plexing se puede inducir la recombinación de las secciones izquierda y derecha del dominio variable del anticuerpo mediante el uso de enzimas de restricción de tipo II y se puede generar así una población en secuencias "optimizadas" para un mayor número de residuos aminoacídos...(AU)