Role of mast cells in ischemic acute renal failure / Participação de mastocitos na lesão renal induzida por isquemia/reperfusão

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Renal ischemia is the main cause of acute renal failure in both native and transplanted kidneys. Ischemia/reperfusion lesion includes changes in renal hemodynamic, endothelial and tubular cell lesion, and inflammatory process, resulting in endothelial cell activation, increased adhesion of endothelial cells and leukocytes, migration of circulating cells to damaged tissue and microvascular dysfunction. While macrophages and T cells are usually analyzed in this model, mast cells, another group of inflammatory cells, are forgotten. Previous studies have shown that mast cells are involved in renal fibrosis, but its participation in the acute phase of renal injury remains unknown. In this study we hypothesized that the presence of mast cells in response to ischemia reperfusion lesion could be a risk factor for the development of renal fibrosis. Male Wistar rats undergone bilateral renal artery clamping for 45 minutes, and were sacrificed from 0 to 14 days after reperfusion. At each study point, renal function, (serum creatinine) and renal morphology (PAS staining), presence of cell proliferation (PCNA), inflammatory cells (macrophages, T cells and mast cells), as well as the expression of pro inflammatory (osteopontin), de-differentiation (vimentin) and pro fibrotic (a smooth muscle cell actin- aSMA ) markers were analyzed. All studied animals developed acute renal failure, confirmed by the increase in serum creatinine and presence of degenerative tubular cell lesions in outer medulla, from D1. Seven days after reperfusion the regenerative process started, with decrease in serum creatinine levels and increase in number of regenerative tubular cells. Interstitial inflammatory response in medulla, analyzed by PCNA stained, peaked at D3. Mast cells was the early detected cell type (D1), followed by both macrophages and T cells at D3.However, while macrophages and T cells infiltrates decreased from D7, mast cell remained in medullar interstitium, with a peak in D14. Osteopontin expression in medulla was observed at early points (D1), and remained constant till D7. Vimentin increased from D3, peaking from D5-D7. Despite a reduction of osteopontin and vimentin expression was observed at D14, these values were still higher than in control animals (Sham). Myofibroblasts, identified by aSMA staining were observed in medulla from D3, and persisted until the end of study period (D14). These data suggests that mast cells are involved in the tissue response to ischemic injury, with an early infiltration and persisting during the repare/scare phase. Association with macrophages and T cells suggests the participation of mast cells in the early inflammatory response. However, its persistence and association with vimentin and myofibroblasts suggests the participation in both renal repare and scarring process

ASSUNTO(S)

reperfusion (physiology) acute renal failure mastocitos mast cells insuficiencia renal aguda inflammation reperfusão (fisiologia) ischemia isquemia inflamação

Documentos Relacionados