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Previous issue date: 2012-08-17 / 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 (HSCs) play a key role in the process of fibrogenesis. In normal liver, HSCs are quiescent and its main function is to store vitamin A. During liver injury, these cells undergo activation, become myofibroblasts and acquire fibrogenic properties. Capsaicin, the active ingredient of red pepper has been extensively studied in recent years for possessing a wide range of pharmacological properties, including analgesic, anti-inflammatory, antiproliferative and anticarcinogenic in a variety of cell types. Therefore, the aim of this study was to investigate the in vitro effects of capsaicin on deactivation, differentiation and proliferation of HSCs, besides studying the possible mechanisms involved. The results showed that capsaicin is capable of inducing the quiescent phenotype in HSCs via PPARγ activation and blockage of TGF-β signaling. Increased levels of antifibrotic cytokines (IFN-γ and IL-10) and the reduction of pro-inflammatory and pro-fibrotic mediators (COX-2, MCP-1, type I collagen) showed that capsaicin inhibits the activation and migration of these cells. Furthermore, the mechanism used by capsaicin to inhibit cell proliferation is via cell cycle arrest. These findings demonstrate that capsaicin has the potential to be a novel therapeutic agent in the treatment of liver fibrosis due to its antifibrogenic and antiproliferative actions. / A fibrose hep?tica ? a resposta cicatricial do f?gado a les?es repetidas, caracterizada pelo rompimento da arquitetura hep?tica associada ao aumento da express?o dos componentes da matriz extracelular. As c?lulas estreladas hep?ticas (HSCs) desempenham um papel-chave no processo de fibrog?nese. No f?gado normal, as HSCs 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. A capsaicina, princ?pio ativo da pimenta vermelha, tem sido muito estudada nos ?ltimos anos por possuir uma extensa gama de propriedades farmacol?gicas, que incluem efeitos analg?sicos, anti-inflamat?rios, antiproliferativos e anticarcinog?nicos em uma variedade de tipos celulares. Por essa raz?o, o objetivo deste estudo foi investigar os efeitos in vitro da capsaicina na inativa??o, diferencia??o e prolifera??o das HSCs, al?m de estudar os poss?veis mecanismos envolvidos. Os resultados obtidos mostraram que a capsaicina ? capaz de induzir o fen?tipo quiescente nas HSCs via ativa??o de PPARγ e bloqueio da sinaliza??o de TGF-β. O aumento nos n?veis de citocinas antifibr?ticas (IFN-γ e IL-10) e a diminui??o de mediadores pr?inflamat?rios e pr?-fibr?ticos (COX-2, MCP-1, col?geno tipo I) comprovaram que a capsaicina inibe a ativa??o e migra??o dessas c?lulas. Al?m disso, o mecanismo utilizado pela capsaicina para inibir a prolifera??o celular ? via parada do ciclo celular. Essas descobertas mostram que a capsaicina tem potencial para ser um novo agente terap?utico no tratamento da fibrose hep?tica devido a suas a??es antifibrog?nicas e antiproliferativas.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/5446 |
| Date | 17 August 2012 |
| Creators | Bitencourt, Shanna |
| 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/doctoralThesis |
| 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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