Development of therapeutic angiogenesis using peripheral blood stem cells

血管内皮祖细胞和造血干细胞是从普通前体细胞分化而来的，这些细胞来源于成人的骨髓。由于粒细胞集落刺激因子(G-CSF)是一种强大的造血细胞因子，可以诱导HSC动员，我们在体内检测了GCSF是否能动员内皮祖细胞进入外周循环，并对缺血诱导的新生血管进行调节。重组人粒细胞集落刺激因子(rhG-CSF)在大鼠背部皮肤注射(5微g/kg/d×7d，n=5)可增加循环白细胞数，停止注射后恢复到基线水平，因此具有一定的功能活性。外周血单个核细胞(MNC)培养结果显示，经rhG-CSF治疗后分化的EPC数量显著减少(42±7vs.13±2)个/视野，p&lt；0.01)。然后，我们测试了重组人粒细胞集落刺激因子是否能在后肢缺血的大鼠模型中调节新生血管。对照组大鼠注射生理盐水、…治疗组大鼠自肢体手术治疗坐骨神经痛当天开始在背部皮肤上应用rhG-CSF。激光多普勒血流仪和组织毛细血管密度分析显示，坐骨神经松弛引起的新生血管形成和血流恢复在两组间无显著差异。在大鼠中，rhG-CSF似乎是体内EPC动员的负调节因子，尽管它不改变缺血诱导的出生后新生血管的程度。接下来，我们研究了低氧是否会调节人外周血巨噬细胞来源的EPC的分化和功能。PB-MNC亚群在缺氧或缺氧条件下均可形成EPC样贴壁(AT)细胞。然而，与正常氧相比，低氧可显著促进PB-MN Cs向AT细胞分化。在体内，当细胞被移植到免疫缺陷裸鼠的缺血后肢时，低氧条件下的AT细胞比常氧条件下的AT细胞显著增强新生血管的效率。结论：低氧直接刺激培养的人外周血单核细胞分化为EPC样AT细胞。此外，低氧还可增强AT细胞的血管生成能力。较少

Endothelial precursor cells (EPCs) and hematopoietic stem cells (HS Cs) differentiate from common precursor cells, and these cells originate from bone marrow in adults. Because granulocyte-colony stimulating factor (G-CSF) is a potent hematopoietic cytokine and can induce HSC mobilization, we tested whether GCSF could mobilize EPCs into peripheral circulation and modulate ischemia-induced postnatal neovascularization in vivo. Recombinant human G-CSF (rhG-CSF) had functional activity in rats because injection of rhG-CSF (5 microg/kg/d x 7d, n=5) on the dorsal skin increased circulating leukocyte count, which returned to the baseline levels after the cessation of the injection. Peripheral blood mononuclear cell (MNC) culture assay revealed that the number of differentiated EPCs significantly decreased after rhG-CSF treatment (42±7 vs. 13±2 EPCs /field, p<.0.01). We then tested whether rhG-CSF modulates neovascularization in a rat model of hindlimb ischemia. Control rats received saline, … More while rats in the treatment group received rhG-CSF on the dorsal skin starting on the day of limb surgery for ischernia. Laser Doppler blood flowmetry and tissue capillary density analysis revealed that the ischeniia-induced neovascularizalion and blood flow recovery did not differ significantly between the two groups. In rats, rhG-CSF seemed to be a negative regulator for the in vivo EPC mobilization although it did not alter the extent of the ischemia-induced postnatal neovascularization.We next examined whether hypoxia would modulate differentiation and function of human PB-MN Cderived EPCs. Subset of PB-MNCs gave rise to EPC-like attaching (AT) cells under eitherjiormoxic or hypoxic conditions. However, hypoxia much enhanced the differentiation of AT cells from PB-MN Cs compared to nomioxia. In vivo neovascularization efficacy was significantly enhanced by hypoxiaconditioned AT cells compared to normoxia-conditioned AT cells when cells were transplanted into the ischemic hindlimb of immunodeficient nude rats. in conclusion, hypoxia directly stimulated differentiation of EPC-like AT cells from human PB-MNC culture. Moreover, hypoxia enhanced the angiogenic efficacies of AT cells. Less