Reichel Christoph A, Khandoga Andrej, Anders Hans-Joachim, Schlöndorff Detlef, Luckow Bruno, Krombach Fritz
Institute for Surgical Research, Arbeitsgruppe Klinische Biochemie, University of Munich, Germany.
J Leukoc Biol. 2006 Jan;79(1):114-22. doi: 10.1189/jlb.0605337. Epub 2005 Nov 7.
Leukocyte infiltration of reperfused tissue is a key event in the pathogenesis of ischemia-reperfusion. However, the role of chemokine receptors Ccr1, Ccr2, and Ccr5 for each single step of the postischemic recruitment process of leukocytes has not yet been characterized. Leukocyte rolling, firm adherence, transendothelial, and extravascular migration were analyzed in the cremaster muscle of anaesthetized C57BL/6 mice using near-infrared reflected light oblique transillumination microscopy. Prior to 30 min of ischemia as well as at 5, 30, 60, 90, and 120 min after onset of reperfusion, migration parameters were determined in wild-type, Ccr1-/-, Ccr2-/-, and Ccr5-/- mice. Sham-operated wild-type mice without ischemia were used as controls. No differences were detected in numbers of rolling leukocytes among groups. In contrast, the number of firmly adherent leukocytes was increased significantly in wild-type mice as compared with sham-operated mice throughout the entire reperfusion phase. Already after 5 min of reperfusion, this increase was reduced significantly in Ccr1-/- and Ccr5-/- mice, whereas only in Ccr2-/- mice, was adherence attenuated significantly at 120 min after onset of reperfusion. Furthermore, after 120 min of reperfusion, the number of transmigrated leukocytes (>80% Ly-6G+ neutrophils) was elevated in wild-type mice as compared with sham-operated animals. This elevation was significantly lower in Ccr1-/-, Ccr2-/-, and Ccr5-/- mice. Leukocyte extravascular migration distances were comparable among groups. In conclusion, these in vivo data demonstrate that Ccr1, Ccr2, and Ccr5 mediate the postischemic recruitment of neutrophils through effects on intravascular adherence and subsequent transmigration.
再灌注组织中的白细胞浸润是缺血再灌注发病机制中的关键事件。然而,趋化因子受体Ccr1、Ccr2和Ccr5在缺血后白细胞募集过程的每个步骤中所起的作用尚未明确。使用近红外反射光斜射显微镜,在麻醉的C57BL/6小鼠的提睾肌中分析白细胞滚动、牢固黏附、跨内皮和血管外迁移情况。在缺血30分钟前以及再灌注开始后5、30、60、90和120分钟,测定野生型、Ccr1-/-、Ccr2-/-和Ccr5-/-小鼠的迁移参数。未进行缺血操作的假手术野生型小鼠用作对照。各组间滚动白细胞数量未检测到差异。相反,在整个再灌注阶段,与假手术小鼠相比,野生型小鼠中牢固黏附的白细胞数量显著增加。再灌注5分钟后,Ccr1-/-和Ccr5-/-小鼠中这种增加显著减少,而只有Ccr2-/-小鼠在再灌注开始后120分钟时黏附才显著减弱。此外,再灌注120分钟后,与假手术动物相比,野生型小鼠中迁移的白细胞(>80% Ly-6G+中性粒细胞)数量升高。在Ccr1-/-、Ccr2-/-和Ccr5-/-小鼠中,这种升高显著降低。各组间白细胞血管外迁移距离相当。总之,这些体内数据表明,Ccr1、Ccr2和Ccr5通过影响血管内黏附和随后的迁移介导缺血后中性粒细胞的募集。