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Avalia??o do efeito da (+)-catequina em c?lulas estreladas hep?ticas

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Previous issue date: 2012-01-27 / This study aimed to evaluate the antiproliferative effect of catechin, as if it has the capacity to reverse the phenotype of GRX cells, and the mechanisms involved in these outcomes. We evaluated the growth and cell proliferation in hepatic stellate cell line activated, the GRX, which were treated with catechin, and cocoa extract, and between the possible mechanisms involved in cell growth was assessed by cell necrosis release of lactate dehydrogenase, apoptosis, by expression of caspase 3 and PARP, as well as the expression of autogagia LC3. The cell cycle was measured by the expression of p53 and p27, as well as inflammatory pathways of IL-6 and COX-2 were assessed by RTPCR Real-time quantification and fibrogenic factor TGF-β. The phenotypic reversion was determined by the presence of fat in the cells with Oil-Red, as well as the expression of PPAR γ, an important regulator of adipogenesis. We evaluated the total collagen and collagen type 1 cells after treatment. It can be seen that both catechin as the cocoa extract decreased the cell growth and proliferation and that this decrease was not due to necrosis and even the activation of apoptosis and autophagy. Catechin induced cell cycle arrest by the reduction of p53 and p27, as well as decreasing the expression of inflammatory proteins such as IL-6 and COX-2 and TGF-β factor fibrogenic. The phenotypic reversion, can observe the presence of fat droplets in the cells after treatment with catechin and cocoa extract, as well as a reduction in collagen type I and an increase in expression following treatment with PPAR γ catechin. In conclusion, catechin decreases cell growth GRX, probably anti-inflammatory activity and for stopping the cell cycle. Catechin decreases the synthesis of TGF-β by cells demonstrating the potential antifibrotic effect. It also presents the property to revert the activated phenotype of GRX cells to a quiescent state and this mechanism may be via activation of PPAR gamma metabolic pathway. / O presente trabalho teve como objetivo avaliar o efeito antiproliferativo da catequina, assim como, se esta apresenta capacidade de reverter o fen?tipo das c?lulas GRX, e quais os mecanismos envolvidos nestes desfechos. Foi avaliado o crescimento e prolifera??o celular em linhagem de c?lulas estreladas hep?ticas ativadas, as GRX, as quais foram tratadas com catequina e extrato de cacau, e entre os poss?veis mecanismos envolvidos no crescimento celular foi avaliada necrose celular pela libera??o da lactato desidrogenase, apoptose, pela express?o de Caspase 3 e PARP, assim como, autogagia pela express?o de LC3. O ciclo celular foi avaliado pela express?o de p53 e p27, assim como, as rotas inflamat?rias da IL-6 e COX-2 foram avaliadas por RT-PCR em tempo real e a quantifica??o do fator fibrog?nico TGF-β. A revers?o fenot?pica foi avaliada pela presen?a de gordura nas c?lulas, por Oil-Red, assim como, pela express?o de PPARγ, um importante fator regulador da adipog?nese. Foi avaliado o col?geno total e o col?geno do tipo 1 nas c?lulas ap?s os tratamentos. Pode-se observar que tanto a catequina como o extrato de cacau diminuiu o crescimento e prolifera??o celular e que esta diminui??o n?o foi por necrose e nem mesmo pela ativa??o da apoptose e autofagia. A catequina induziu uma parada no ciclo celular, pela redu??o da p53 e p27, assim como, diminuiu a express?o de prote?nas inflamat?rias como a IL-6 e COX-2 e o fator fibrog?nico TGF-β. Quanto a revers?o fenot?pica, pode-se observar a presen?a de got?culas de gordura nas c?lulas ap?s tratamento com catequina e extrato de cacau, assim como, uma diminui??o do col?geno tipo I e um aumento na express?o de PPARγ ap?s tratamento com catequina. Em conclus?o, a catequina diminui o crescimento das c?lulas GRX, provavelmente por atividade anti-inflamat?ria e por parar o ciclo celular. A catequina diminui o s?ntese de TGF-β pelas c?lulas demostrando um potencial efeito antifibr?tico. Apresenta ainda, a propriedade de reverter o fen?tipo ativado das c?lulas GRX para um estado quiescente e este mecanismo pode ser via ativa??o da rota metab?lica PPARγ.

Identiferoai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/5431
Date27 January 2012
CreatorsMoraes, Cristina Machado Bragan?a de
ContributorsOliveira, Jarbas Rodrigues de
PublisherPontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Biologia Celular e Molecular, PUCRS, BR, Faculdade de Bioci?ncias
Source SetsIBICT Brazilian ETDs
LanguagePortuguese
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis
Formatapplication/pdf
Sourcereponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS
Rightsinfo:eu-repo/semantics/openAccess
Relation8198246930096637360, 600, 600, 36528317262667714

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