RESUMO
The injured skin produces a number of mediators that directly or indirectly modulate cell chemotaxis, migration, proliferation, and angiogenesis. Components of the kinin pathway including the kinin B1 receptor (B1R) have been found to occur in the human skin, but information about its role on keratinocyte biology is still scarce. Our aim was to determine whether stimulation of B1R causes the secretion of IL-4 and/or VEGF from human keratinocytes and to evaluate the role of the B1R agonist Lys-des[Arg(9)]bradykinin and IL-4 on various stages of angiogenesis, such as cell migration, proliferation, and release of metalloproteases. By using ELISA and Western blotting, we showed that HaCaT keratinocytes stimulated with the B1R agonist release IL-4 and VEGF. Stimulation of B1R also caused transient c-JunN-terminal kinase phosphorylation and JunB nuclear translocation, transcription factor that regulates IL-4 expression. The 3D-angiogenesis assay, performed on spheroids of EA.hy923 endothelial cells embedded in a collagen matrix, showed that their cumulative sprout area increased significantly following stimulation with either IL-4 or B1R agonist. Furthermore, these ligands produced significant endothelial cell migration and release of metalloproteases 2 and 9, but did not increase endothelial cell proliferation as measured by 5-bromo-2'-deoxyuridine incorporation. Our results provide experimental evidence that establishes IL-4 and B1R agonist as important angiogenic factors of relevance for skin repair.
Assuntos
Células Endoteliais/metabolismo , Interleucina-4/metabolismo , Interleucina-4/farmacologia , Queratinócitos/metabolismo , Neovascularização Fisiológica/fisiologia , Receptor B1 da Bradicinina/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Proteínas Angiogênicas/farmacologia , Linhagem Celular , Movimento Celular , Proliferação de Células , Meios de Cultivo Condicionados/farmacologia , Ativação Enzimática , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Calidina/análogos & derivados , Calidina/farmacologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-jun , Interferência de RNA , RNA Interferente Pequeno/genética , Receptor B1 da Bradicinina/agonistas , Receptor B1 da Bradicinina/genética , Transdução de Sinais/fisiologia , Pele/citologia , Pele/metabolismo , Esferoides CelularesRESUMO
BACKGROUND: In sites with diminished bone volume, the osseointegration of dental implants can be compromised. Innovative biomaterials have been developed to aid successful osseointegration outcomes. PURPOSE: The aim of this study was to evaluate the osteogenic potential of angiogenic latex proteins for improved bone formation and osseointegration of dental implants. MATERIALS AND METHODS: Ten dogs were submitted to bilateral circumferential defects (5.0 × 6.3 mm) in the mandible. Dental implant (3.3 × 10.0 mm, TiUnite MK3™, Nobel Biocare AB, Göteborg, Sweden) was installed in the center of the defects. The gap was filled either with coagulum (Cg), autogenous bone graft (BG), or latex angiogenic proteins pool (LPP). Five animals were sacrificed after 4 weeks and 12 weeks, respectively. Implant stability was evaluated using resonance frequency analysis (Osstell Mentor, Osstell AB, Göteborg, Sweden), and bone formation was analyzed by histological and histometric analysis. RESULTS: LPP showed bone regeneration similar to BG and Cg at 4 weeks and 12 weeks, respectively (p ≥ .05). Bone formation, osseointegration, and implant stability improved significantly from 4 to 12 weeks (p ≤ .05). CONCLUSION: Based on methodological limitations of this study, Cg alone delivers higher bone formation in the defect as compared with BG at 12 weeks; compared with Cg and BG, the treatment with LPP exhibits no advantage in terms of osteogenic potential in this experimental model, although overall osseointegration was not affected by the treatments employed in this study.
Assuntos
Aumento do Rebordo Alveolar/métodos , Regeneração Óssea/efeitos dos fármacos , Implantes Dentários , Hevea , Látex , Osseointegração/efeitos dos fármacos , Proteínas de Plantas/farmacologia , Proteínas Angiogênicas/farmacologia , Animais , Coagulação Sanguínea , Transplante Ósseo , Cães , Masculino , Mandíbula/cirurgia , Neovascularização Fisiológica/efeitos dos fármacosRESUMO
BACKGROUND: Leptin is a potent direct angiogenic factor that stimulates endothelial cell migration and activation in vitro and angiogenesis in vivo. In addition, leptin has been discussed to play an important role in angiogenesis, as it promotes the formation of new blood vessels. PURPOSE: The effect of exogenously administered leptin on the healing process of a full tissue burn wound model. METHODS: Sixty-three Sprague-Dawley male rats were used. Full tissue burn wound was created by electrocautery. The width of the pin was 0.3 cm; its length was 2 cm and was used at the "cut" modulation. Rats were divided into seven groups of nine animals each. Burn wounds were injected with murine recombinant leptin and the rats were sacrificed 3, 7 and 9 days after surgery. Every group had obtained three animals for the three different days of sacrifice. Three different leptin doses of 250 pg/ml, 500 pg/ml and 1000 pg/ml were used in different animal groups (A, B and C). For every one of the three leptin doses used, another animal group was evaluated by using the combined injection of leptin and antileptin (A1, B1, and C1), in order to study the inhibitory effect to the leptin factor. Nine rats were served as controls. These were injected with 0.3 ml water for injection solution and sacrificed at the same time intervals. After sacrifice of the animals, the skin was grossly determined by its appearance, colour and texture. Full thickness burn wounds were dissected for histological examination. A qualitative analysis of angiogenesis in the burn wound was conducted following a standard hematoxylin and eosin stain. The wound tissue samples from each experimental group underwent immunohistochemical evaluation of microvessel density by endothelial cell staining with mouse anti-rat CD 34 monoclonal antibody. RESULTS: The most impressive growth of new blood vessels appeared seven and nine days after treatment with the highest leptin doses. There were no significant differences in microvessel density between the seventh and the ninth postoperative day among different groups treated with leptin. All wounds from the control group, as well as those from animal groups treated with the combined injection of leptin and antileptin did not develop any new vessels. CONCLUSION: Exogenous administration of recombinant leptin increases early tissue angiogenesis in the burn wound level of an experimental animal model.
Assuntos
Proteínas Angiogênicas/farmacologia , Queimaduras por Corrente Elétrica/tratamento farmacológico , Leptina/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Proteínas Angiogênicas/administração & dosagem , Animais , Queimaduras por Corrente Elétrica/patologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Leptina/administração & dosagem , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de TempoRESUMO
BACKGROUND: Leptin is a potent direct angiogenic factor that stimulates endothelial cell migration and activation in vitro and angiogenesis in vivo. In addition, leptin has been discussed to play an important role in angiogenesis, as it promotes the formation of new blood vessels. PURPOSE: The effect of exogenously administered leptin on the healing process of a full tissue burn wound model. METHODS: Sixty-three Sprague-Dawley male rats were used. Full tissue burn wound was created by electrocautery. The width of the pin was 0.3 cm; its length was 2 cm and was used at the "cut" modulation. Rats were divided into seven groups of nine animals each. Burn wounds were injected with murine recombinant leptin and the rats were sacrificed 3, 7 and 9 days after surgery. Every group had obtained three animals for the three different days of sacrifice. Three different leptin doses of 250 pg/ml, 500 pg/ml and 1000 pg/ml were used in different animal groups (A, B and C). For every one of the three leptin doses used, another animal group was evaluated by using the combined injection of leptin and antileptin (A1, B1, and C1), in order to study the inhibitory effect to the leptin factor. Nine rats were served as controls. These were injected with 0.3 ml water for injection solution and sacrificed at the same time intervals. After sacrifice of the animals, the skin was grossly determined by its appearance, colour and texture. Full thickness burn wounds were dissected for histological examination. A qualitative analysis of angiogenesis in the burn wound was conducted following a standard hematoxylin and eosin stain. The wound tissue samples from each experimental group underwent immunohistochemical evaluation of microvessel density by endothelial cell staining with mouse anti-rat CD 34 monoclonal antibody. RESULTS: The most impressive growth of new blood vessels appeared seven and nine days after treatment with the highest leptin doses. There were no significant...
INTRODUÇÃO: A leptina é um potente fator angiogênico que estimula a migração e a ativação de células endoteliais in vitro e a angiogênese in vivo. Além disso, a leptina tem sido considerada importante na angiogênese pois ela promove a formação de novos vasos sanguíneos. OBJETIVO: Investigar o efeito da leptina administrada por via exógena no processo de cicatrização em um modelo experimental de queimadura. MÉTODOS: Foram utilizados sessenta e três ratos Sprague-Dawley, machos. A lesão de espessura total da queimadura foi realizada por eletrocautério. O dano tecidual foi de 0.3 cm numa extensão de 2 cm tendo sido empregada o módulo de "corte"do eletrocautéio. Os ratos foram distribuídos em sete grupos de nove animais. As lesões por queimadura receberam leptina recombinante. Os animais foram sacrificados 3, 7 e 9 dias após o ato operatório. Obteve-se três animais de cada grupo nos três períodos estipulados. Três diferentes dosagens de leptina: 250 pg/ml, 500 pg/ml e 1000 pg/ml foram aplicados nos três diferentes grupos (A, B e C). Para cada uma das três dosagens de leptina, outro grupo de animais foi avaliado pelo uso de injeção combinada de leptina e antileptina (A1, B1 e C1) no sentido de investigar o efeito inibitório do fator leptina. Nove ratos serviram de controles. Estes foram submetidos à injeção de 0.3 ml de água e sacrificados nos mesmos intervalos de tempo. Após o sacrifício dos animais, o tegumento foi avaliado por sua aparência, cor e textura. Fragmentos das feridas queimadas foram ressecadas para exame histológico. A análise qualitativa de angiogênese, na ferida queimada, seguia o padrão da coloração de hematoxilina e eosina. Cada fragmento de tecido, de cada grupo experimental, foi submetido à avaliação imunohistoquímica da densidade dos microvasos pela coloração da célula endotelial por anti-rato CD 34 anticorpo monoclonal. RESULTADOS: O desenvolvimento de novos vasos sanguíneos foi mais significativo após sete e nove dias...