RESUMO
Inflammatory bowel disease (IBD) may result from exaggerated stimulation of the mucosal immune system by luminal bacterial flora. Bacterial products are recognized by pattern recognition receptors such as Toll-like receptors (TLRs), which are key regulators of the innate immune system. Therefore, the expression of TLR2, TLR3 and TLR4 in colonic biopsy samples taken from children with active IBD were studied and compared to controls. Colonic biopsy samples were collected from macroscopically inflamed and non-inflamed regions of the mucosa of 12 children with freshly diagnosed IBD (fdIBD) and 23 children with relapsed IBD (rIBD). Specimens were also obtained from eight controls. TLR2, TLR3 and TLR4 mRNA expression and protein levels were determined by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot. We found higher TLR2 and TLR4 mRNA and protein levels in the inflamed colonic mucosa of children with fdIBD and rIBD compared to controls. In the non-inflamed colonic mucosa of children with fdIBD and rIBD, TLR2 and TLR4 mRNA and protein levels were similar to controls. TLR2 and TLR4 mRNA and protein levels also did not differ between children with fdIBD or rIBD in either inflamed or non-inflamed colonic mucosa. TLR3 mRNA expression and protein levels were similar in all groups studied. Our results of increased levels of TLR2 and TLR4 in the inflamed colonic mucosa of children with IBD confirm the hypothesis that innate immunity has an important role in the pathogenesis of this disease.
Assuntos
Colo , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Adolescente , Western Blotting/métodos , Estudos de Casos e Controles , Criança , Suscetibilidade a Doenças , Feminino , Humanos , Imunidade Inata , Doenças Inflamatórias Intestinais/imunologia , Mucosa Intestinal/imunologia , Masculino , RNA Mensageiro/análise , Recidiva , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatísticas não Paramétricas , Receptor 2 Toll-Like/análise , Receptor 2 Toll-Like/genética , Receptor 3 Toll-Like/análise , Receptor 3 Toll-Like/genética , Receptor 3 Toll-Like/metabolismo , Receptor 4 Toll-Like/análise , Receptor 4 Toll-Like/genéticaRESUMO
The aim of this study was to evaluate the role of proangiogenic growth factors in an experimental model of ischemia/reperfusion injury (I/R) in both normotensive and hypertensive rats. Renal ischemic injury was induced in transgenic rats rendered hypertensive due to renin overproduction [TGR (mREN-2)-27] and in normotensive Hannover Sprague-Dawley rats (HanSD). Animals were treated for 12 weeks with either tacrolimus (TAC, 0.1 mg/kg per day, intramuscularly [IM]) or placebo. After 12 weeks, kidneys were harvested for morphologic, immunohistochemical, and RT-PCR analysis. Both normotensive and hypertensive untreated rats developed significantly greater proteinuria and glomerulosclerosis compared with TAC-treated rats. Immunohistologically, TGR showed higher basic fibroblast growth factor (bFGF) protein expression compared with normotensive HanSD. TAC-treated rats had higher bFGF protein expression than untreated rats. Vascular endothelial growth factor (VEGF) protein expression in glomeruli was more increased in TGR after I/R than in sham-operated animals. TAC-treated TGR hosts developed higher VEGF mRNA expression compared with both untreated and sham groups; however, there were no differences between treated and untreated normotensive HanSD animals. bFGF is involved in the fibrogenesis induced by hypertension and I/R injury. The nature of the increase in proangiogeneic growth factor expression among tacrolimus-treated animals remains to be elucidated.
