Department of Molecular and Medical Biophysics, Medical University of Lodz, Poland.
Thromb Res. 2011 Nov;128(5):452-7. doi: 10.1016/j.thromres.2011.06.011. Epub 2011 Jul 12.
Previous studies showed that lumican, a small leucine-rich proteoglycan that binds to α2 integrin I domain, is an efficient inhibitor of cell adhesion and migration. In this report, we tested its effect on angiogenesis in vitro and in vivo.
Effect of lumican on angiogenesis was evaluated by in vitro capillary tube formation test performed between Fibrin II Gels or in Matrigel™ and in vivo by Matrigel(™) plug assay in BALB/c mice. Changes in matrix metalloproteinases expression caused by lumican were analyzed in endothelial cells by real-time PCR, Western immunoblotting and gelatin zymography.
In unchallenged endothelial cells, Matrigel™ induced robust capillary morphogenesis. In contrast, tube formation was dramatically reduced by lumican, and by siRNA to β1 integrin subunit mRNA but not by control siRNA. Similarly, lumican effectively inhibited neovascularization in vivo in assays using Matrigel™ plugs formed in BALB/c mice. Interestingly, lumican significantly reduced expression of matrix metalloproteinases, particularly MMP-14 that is known to activate other MMPs in close vicinity of endothelial cell membranes.
Our results provide strong evidence that lumican affects angiogenesis both by interfering with α2β1 receptor activity and downregulating proteolytic activity associated with surface membranes of endothelial cells.
先前的研究表明，富含亮氨酸的小蛋白聚糖（lumican）与 α2 整合素 I 结构域结合，是细胞黏附和迁移的有效抑制剂。本研究旨在检测其在体外和体内对血管生成的影响。
通过纤维蛋白 II 凝胶或 Matrigel™ 之间的体外毛细血管形成试验以及 BALB/c 小鼠的 Matrigel™ plugs 测定法，评估 lumican 对血管生成的影响。通过实时 PCR、Western 免疫印迹和明胶酶谱分析，检测 lumican 引起的基质金属蛋白酶表达的变化。
在未经刺激的内皮细胞中，Matrigel™ 诱导出强大的毛细血管形态发生。相比之下，lumican 显著减少了管腔形成，而用 β1 整合素亚基 mRNA 的 siRNA 而非对照 siRNA 则不会。同样，lumican 有效地抑制了体内的血管生成，在使用 Matrigel™ 塞形成的 BALB/c 小鼠实验中得到了证实。有趣的是，lumican 显著降低了基质金属蛋白酶的表达，特别是已知在靠近内皮细胞膜的 MMP-14，其能激活其他 MMPs。
我们的结果提供了有力的证据，表明 lumican 通过干扰 α2β1 受体活性和下调与内皮细胞表面相关的蛋白水解活性，影响血管生成。
