No abstract

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.

Cardiovascular disease (CVD) is the leading cause of death in modern society. The adult heart innately lacks the capacity to repair and regenerate the damaged myocardium from ischemic injury. Limited understanding of cardiac tissue repair process hampers the development of effective therapeutic solutions to treat CVD such as ischemic cardiomyopathy. In recent years, rapid emergence of induced pluripotent stem cells (iPSC) and iPSC-derived cardiomyocytes (iCM) presents a valuable opportunity to replenish the functional cells to the heart. The therapeutic effects of iPSC-derived cells have been investigated in many preclinical studies. However, the underlying mechanisms of iPSC-derived cell therapy are still unclear and limited engraftment of iCMs are well known. One facet of their mechanism is the paracrine effect of the transplanted cells. Microvesicles such as exosomes secreted from the iCMs exert protective effects by transfering the endogenous molecules to salvage the injured neighboring cells by regulating apoptosis, inflammation, fibrosis and angiogenesis. In this review, we will focus on the current advances in the exosomes from iPSC-derivatives and discuss their therapeutic potential in the treatment of CVD.