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Previous issue date: 2013-02-26 / Liver fibrosis is the wound healing response to repeated injury of the liver. It is characterized by disruption of the liver architecture associated with increased expression of extracellular matrix components. Hepatic stellate cells (HSC) play a key role in liver fibrogenesis. In normal liver, HSC are quiescent and its main function is to store vitamin A. During liver injury, these cells undergo activation, become myofibroblasts and acquire fibrogenic properties. Activation of PPARγ (peroxisome proliferator-activated receptor gamma) and inhibition of fibrogenic molecules are potential strategies to block HSC activation and differentiation. Aware that the process of hepatic fibrosis involves inflammatory mediators, various anti-inflammatory substances have been studied in an attempt to revert fibrosis. The purpose of this study was to investigate the in vitro effects of fructose-1,6-bisphospahte (FBP) on HSC phenotype. The results demonstrated that FBP induced quiescent phenotype in HSC via PPARγ activation. Significant decrease in type I collagen mRNA expression was observed in the first 24h of treatment. These events preceded the reduction of TGF-β1 (transforming growth factor-beta) and total collagen secretion. Thus, FBP promoted downregulation of HSC activation by its antifibrotic and anti-inflammatory actions. These findings demonstrate that FBP may have potential as a novel therapeutic agent for the treatment of liver fibrosis. / A fibrose hep?tica ? a resposta cicatricial do f?gado a les?es continuadas, caracterizada pelo rompimento da arquitetura hep?tica associada ao aumento da express?o dos componentes da matriz extracelular. As c?lulas estreladas hep?ticas (HSC) desempenham um papel fundamental no processo de fibrog?nese. No f?gado normal, as HSC encontram-se em sua forma quiescente de dep?sito de vitamina A. Durante a les?o hep?tica, essas c?lulas passam por uma ativa??o fenot?pica, tornam-se miofibroblastos e adquirem propriedades fibrog?nicas. O processo de fibrose hep?tica envolve v?rios mediadores inflamat?rios e, portanto, subst?ncias anti-inflamat?rias tem sido empregadas na tentativa de reverter a fibrose e bloquear a ativa??o e diferencia??o das HSC. A ativa??o de PPARγ (receptor ativado por proliferador de peroxissomo Gama) e a inibi??o de mol?culas fibrog?nicas s?o poss?veis estrat?gias para estes fins. O objetivo deste estudo foi investigar os efeitos in vitro da frutose-1,6-bisfosfato (FBP) sobre o fen?tipo das HSC. Os resultados demonstraram que a FBP ? capaz de induzir o fen?tipo quiescente das HSC via ativa??o de PPARγ. Foi observado nas primeiras 24h de tratamento uma diminui??o significativa da express?o de mRNA de col?geno tipo I. Posteriormente, houve uma redu??o do col?geno total e de TGF-β1 (fator de transforma??o do crescimento beta). Assim, a FBP diminui o estado de ativa??o das HSC por suas a??es antifibr?ticas e anti-inflamat?rias. Estas descobertas demonstram que a FBP pode ser um potencial novo agente terap?utico para o tratamento de fibrose hep?tica.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/5456 |
| Date | 26 February 2013 |
| Creators | Mesquita, Fernanda Cristina de |
| Contributors | Oliveira, Jarbas Rodrigues de |
| Publisher | Pontif?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 Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 8198246930096637360, 600, 600, 36528317262667714 |
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