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Background: Accumulating evidence shows the potential of bone marrow-derived endothelial colony-forming cells (bmECFCs) as promising tools for vascular repair. However, knowledge about their in vitro expansion, characterization, and functional behavior is still controversial. We demonstrate the in vitro generation of rat bmECFCs and analyze their ability to promote tissue reperfusion in a chronic hind-limb ischemia model., Methods: Either in vitro-generated and characterized autologous bmECFCs or placebo was injected into ischemic hind limbs of Sprague-Dawley rats. Tissue perfusion was quantified by laser Doppler, in perfusion units (PU), at days 0, 15, and 30., Results: Rat bmECFCs acquire a typical phenotype (CD34(+)VEGFR2(+)CD133(+)CXCR4(+)CD45(-)), culture, and functional behavior (Dil-ac-LDL+) in vitro. Injection of autologous bmECFCs improves tissue perfusion in ischemic hind limbs (183.5 ± 3.29 PU(bmECFCs/day 30)versus 131 ± 3.9 PU(controls/day 30), P < 0.001)., Conclusions: We conclude that rat bmECFCs promote ischemic tissue reperfusion and their proangiogenic properties are a potential mechanism for this effect., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Unlabelled: The present clinical trial analyzed the safety of gene therapy using plasmidial constructs expressing vascular endothelial and hepatocyte growth factors in patients with critical limb ischemia. The study included 43 patients: 29 in the treatment group and 14 allocated to the placebo group. The primary end points were the rate of major amputations and the clinical safety of the method. Secondary end points were improvement of pain at rest, walking ability and the ankle/brachial pressure index. The overall major amputation rate was 31.04% in the treatment group and 71.42% in the placebo group (p = 0.029). Pain at rest was improved in 65% of patients in the gene therapy group and in 7% in the placebo group (p = 0.0006). There were no significant adverse effects in the treatment group., Conclusion: Gene therapy with vascular endothelial and hepatocyte growth factors is therapeutically safe and reduces the rate of major amputations and relieves pain at rest in patients with critical limb ischemia.

Several studies have implicated enhanced eicosanoid production in reperfusion injury. The reported study investigated the use of microdialysis in the in vivo measurement of thromboxane levels during reperfusion in ischemic and reperfused experimental free muscle flaps. Microdialysis probes were inserted, via a guide, into the gracilis and semitendinosus free flap in the rat. The probe was perfused at a flow of 5 microl/min, with samples collected at intervals of 20 min, and analyzed by the ELISA technique. Animals were randomly distributed into three groups. After ischemic periods of 2, 4, and 6 hr, respectively, the free muscle flaps were revascularized on the contralateral femoral vessels. The mean thromboxane level during ischemia was 1785.34 +/- 124.81 pg/ml. The mean levels of thromboxane rose significantly (p < 0.05), compared to base level, with 151.65 percent in the 2-hr ischemia group, 192.33 percent in the 4-hr ischemia group, and 294.69 percent in the 6-hr ischemia group, and correlated well with histologic observations. The results suggest that a microdialysis technique, combined with a sensitive assay for measuring thromboxane, is a useful method for in vivo monitoring of inflammatory processes during ischemia and reperfusion. The evolution of thromboxane release following 6 hr of ischemia indicates that this mediator may be involved in facilitation of cell death, following ischemia and reperfusion, since its tissue level correlates with histologic tissue damage.