Role of vascular endothelial growth factor and angiopoietin 1 in renal injury in hemolytic uremic syndrome.

Background/aims: The recovery process from renal injury in hemolytic uremic syndrome (HUS) remains obscure. In order to clarify the role of vascular endothelial growth factor (VEGF) and angiopoietin 1 (Ang-1) in the renal recovery from HUS, we produced a model of mild HUS and examined the renal recovery process.

Methods: We investigated three groups of mice. Group 1 consisted of mice that received an injection of Shiga toxin 2 (Stx2) and lipopolysaccharide (LPS); group 2 consisted of mice that received an injection of low dose of Stx2 and LPS, and group 3 consisted of control mice.

Results: Serum Cr levels in group 1 were greater than those in group 2, and all mice in group 1 died, whereas all mice in group 2 remained alive. Endothelial injury at 24 h in group 1 was higher than in group 2. Electron-microscopic findings demonstrated that the endothelial cells formed immature capillary-like lumina from 7 to 28 days with increases in the expression of CD31-positive cells. Glomerular VEGF expression decreased at 72 h in group 1, but gradually increased in group 2. Glomerular Ang-1 expression peaked from 72 h to 28 days. Ang-1 expression was frequently found in the endothelial cell region of vesicle walls simultaneous with increased CD31-positive staining.

Conclusion: Our findings suggest that VEGF and Ang-1 play important roles in the recovery process, particularly in the regeneration of endothelial injury.