2004 年 56 巻 2-4 号 p. 194-205
Background: Peripheral blood-mononuclear cells (PBMNCs), platelets or polymorphonuclear leukocytes (PMNs) contain various angiogenic factors. Methods and Results: Unilateral hindlimb ischemia was surgically induced in athymic nude rats, and fluorescence-labeled human blood cells (PBMNCs-107 cells+platelets-109, PBMNCs-107 cells +platelets-109+PMNsplatelets-109 or PMNs-107) were intramuscularly implanted into the ischemic limbs. Laser Do p pler imaging revealed markedly increased blood perfusion in PBMNC +platelet-implanted limbs (44% increase on day 21, P<0.001) compared with control implantation of human umbilical vascular endothelial cells (HUVEC). The addition of PMNs to PBMNCs +platelets attenuated blood perfusion (27% decrease, P <0.01). Neocapillary densities were increased by implantation of PBMNCs + platelets or platelets alone (3.5- and 2.4-fold, respectively; P<0.001), while PMNs inhibited (32%, P<0.05 )PBMNC+platelet-mediated capillary formation. There was no incorporation of implanted-PBMNCs into neocapillaries, whereas PBMNCs and platelets accumulated around arterioles after implantation. Cellular extract from PBMNCs+platelets, in which vascular endothelial growth factor (VEGF), basic fibroblast growth factor, platelet-derived growth factor-AB, and transforming growth factor-beta were detected, markedly stimulated tubule formation of human umbilical vein vascular endothelial cells. Anti-VEGF neutralizing antibody markedly inhibited tubule formation and in vivo vessel formation. Neutrophil elastase inhibitor blocked the antiangiogenic action of PMNs, whereas inhibitors of oxygen metabolites had no effect. Conclusions: This study demonstrated that implanatation of PBMNCs and platelets into ischemic limbs effectively induces collateral vessel formation by supplying angiogenic factors (mainly VEGF) and cytokines, suggesting that this cell therapy is useful as a novel strategy for therapeutic angiogenesis.
