Decreased level and defective function of circulating endothelial progenitor cells in children with moyamoya disease

Circulating endothelial progenitor cells (EPCs) play an important role in physiological and pathological neovascularization and may be involved in attenuating ischemic diseases. This study aimed to characterize circulating EPCs in moyamoya disease (MMD), one of the most common pediatric cerebrovascular diseases. Twenty-eight children with MMD prior to any surgical treatment and 12 healthy volunteers were recruited. Peripheral blood mononuclear cells (PBMNCs) were isolated and cultured in endothelial cell growth medium. Temporal change of phenotype of cells was analyzed on days 0 and 7. The formation of EPC clusters was evaluated on day 7. The CD34(+), CD133(+), and KDR(+) cells, and the number of EPC clusters was significantly reduced in children with MMD. In controls, CD34(+) cells were significantly decreased on day 7 compared with day 0, but in MMD they were only slightly decreased. The change in KDR(+) cells on day 7 compared with day 0 was the reverse of that for CD34(+) cells. Functional assay of EPC demonstrated less tube formation and increased senescent-like phenotype in children with MMD. Analysis of the circulating EPCs of MMD children reveals decreased level and defective function. This study suggests that circulating EPCs may be associated with MMD pathogenesis.