Department of Internal Medicine, Cardiology and Angiology, Richard Thoma Laboratories for Arteriogenesis, Center for Cardiovascular Research and Experimental and Clinical Research Center, [corrected] Charité-Universitätsmedizin Berlin, Berlin, Germany.
Cerebrovasc Dis. 2012;33(5):419-29. doi: 10.1159/000335869. Epub 2012 Mar 28.
Restoration of cerebrovascular reserve capacity (CVRC) depends on the recruitment and positive outward remodeling of preexistent collaterals (arteriogenesis). With this study, we provide functional evidence that granulocyte colony-stimulating factor (G-CSF) augments therapeutic arteriogenesis in two animal models of cerebral hypoperfusion. We identified an effective dosing regimen that improved CVRC and stimulated collateral growth, thereby improving the outcome after experimentally induced stroke.
We used two established animal models of (a) cerebral hypoperfusion (mouse, common carotid artery ligation) and (b) cerebral arteriogenesis (rat, 3-vessel occlusion). Following therapeutic dose determination, both models received either G-CSF, 40 μg/kg every other day, or vehicle for 1 week. Collateral vessel diameters were measured following latex angiography. Cerebrovascular reserve capacities were assessed after acetazolamide stimulation. Mice with left common carotid artery occlusion (CCAO) were additionally subjected to middle cerebral artery occlusion, and stroke volumes were assessed after triphenyltetrazolium chloride staining. Given the vital role of monocytes in arteriogenesis, we assessed (a) the influence of G-CSF on monocyte migration in vitro and (b) monocyte counts in the adventitial tissues of the growing collaterals in vivo.
CVRC was impaired in both animal models 1 week after induction of hypoperfusion. While G-CSF, 40 μg/kg every other day, significantly augmented cerebral arteriogenesis in the rat model, 50 or 150 μg/kg every day did not show any noticeable therapeutic impact. G-CSF restored CVRC in mice (5 ± 2 to 12 ± 6%) and rats (3 ± 4 to 19 ± 12%). Vessel diameters changed accordingly: in rats, the diameters of posterior cerebral arteries (ipsilateral: 209 ± 7-271 ± 57 μm; contralateral: 208 ± 11-252 ± 28 μm) and in mice the diameter of anterior cerebral arteries (185 ± 15-222 ± 12 μm) significantly increased in the G-CSF groups compared to controls. Stroke volume in mice (10 ± 2%) was diminished following CCAO (7 ± 4%) and G-CSF treatment (4 ± 2%). G-CSF significantly increased monocyte migration in vitro and perivascular monocyte numbers in vivo.
G-CSF augments cerebral collateral artery growth, increases CVRC and protects from experimentally induced ischemic stroke. When comparing three different dosing regimens, a relatively low dosage of G-CSF was most effective, indicating that the common side effects of this cytokine might be significantly reduced or possibly even avoided in this indication.
脑血管储备能力（CVRC）的恢复依赖于已有侧支（动脉生成）的募集和积极的外向重塑。通过这项研究，我们提供了功能证据，表明粒细胞集落刺激因子（G-CSF）在两种脑低灌注动物模型中增强了治疗性动脉生成。我们确定了一种有效的剂量方案，该方案改善了 CVRC 并刺激了侧支生长，从而改善了实验性诱导中风后的结果。
我们使用了两种已建立的脑低灌注动物模型（a）脑低灌注（小鼠，颈总动脉结扎）和（b）脑动脉生成（大鼠，3 血管闭塞）。在确定治疗剂量后，两种模型均接受 G-CSF（40μg/kg，每隔一天）或载体治疗 1 周。乳胶血管造影后测量侧支血管直径。用乙酰唑胺刺激后评估脑血管储备能力。左颈总动脉闭塞（CCAO）的小鼠还接受了大脑中动脉闭塞，三苯基四唑氯化物染色后评估中风体积。鉴于单核细胞在动脉生成中的重要作用，我们评估了（a）G-CSF 对体外单核细胞迁移的影响和（b）体内生长侧支的外膜组织中的单核细胞计数。
在低灌注诱导后 1 周，两种动物模型的 CVRC 均受损。虽然 G-CSF（40μg/kg，每隔一天）显著增强了大鼠模型中的脑动脉生成，但 50 或 150μg/kg 每天并没有显示出任何明显的治疗作用。G-CSF 恢复了小鼠（5±2%至 12±6%）和大鼠（3±4%至 19±12%）的 CVRC。血管直径相应变化：在大鼠中，大脑后动脉的直径（同侧：209±7-271±57μm；对侧：208±11-252±28μm）和在小鼠中，大脑前动脉的直径（185±15-222±12μm）在 G-CSF 组中与对照组相比显着增加。CCAO 后（7±4%）和 G-CSF 治疗后（4±2%），小鼠的中风体积（10%）减少。G-CSF 显著增加了体外单核细胞迁移和体内血管周围单核细胞数量。
G-CSF 增强脑侧支动脉生长，增加 CVRC 并预防实验性缺血性中风。在比较三种不同的剂量方案时，相对较低剂量的 G-CSF 最为有效，这表明该细胞因子的常见副作用在该适应症中可能会显著降低，甚至可能避免。
