The E8 subfragment of laminin promotes locomotion of myoblasts over extracellular matrix.
The E8 subfragment of laminin promotes locomotion of myoblasts over extracellular matrix.
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DOI：
10.1083/jcb.109.2.799
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发表时间：
1989-08
期刊：
影响因子：
--
通讯作者：
von der Mark K
中科院分区：
文献类型：
--
作者：
Goodman SL;Risse G;von der Mark K
用定量视频显微镜分析小鼠成肌细胞在细胞外基质成分层粘连蛋白和纤维连接蛋白上的运动，并在平行的免疫荧光研究中观察细胞骨架的组织。细胞在层粘连蛋白-尼多原复合体上的运动速度是单独在层粘连蛋白上的两倍。层粘连蛋白易位的主要形式是延长片状椭圆形延伸的跳跃周期，然后细胞体快速(约200-小于500微小时-1)移动到延伸的片状椭圆形。层粘连蛋白的运动刺激活性存在于层粘连蛋白长臂的弹性酶消化片段E8中，而包含三个短臂的E1-4片段是不活跃的。无论使用高、中、低包被浓度(约5,000-约10 fmol cm-2)，成肌细胞在纤维连接蛋白上的移动都很差。相反，对层粘连蛋白和E8的运动反应在涂层浓度约为20-50fmol·cm~(-2)时急剧增加，在较高浓度时下降。这种反应与触觉刺激剂的预期反应一致。当细胞在层粘连蛋白和纤维连接蛋白的混合底物上运动时，纤维连接蛋白的作用似乎占主导地位。细胞骨架参与了许多细胞运动过程。在纤维连接蛋白作用6h内，许多细胞表达纽蛋白样局灶性接触，形成应力纤维，并周期性地形成α-肌动蛋白；而在层粘连蛋白上，大多数细胞表现为弥漫的肌动蛋白和α-肌动蛋白以及细小的网状肌动蛋白细胞骨架。我们得出结论，细胞在纤维连接蛋白上运动不良是因为它诱导了细胞骨架的稳定。
The locomotion of murine myoblasts over the extracellular matrix components laminin and fibronectin was analyzed using quantitative videomicroscopy, and the organization of the cytoskeleton was observed in parallel immunofluorescence studies. Cells plated on the laminin- nidogen complex locomoted twice as fast as on laminin alone. The main form of translocation on laminin was a jerky cycle of prolonged lamellipod extension followed by rapid (approximately 200- less than 500 microh h-1) movement of the cell body into the extended lamellipod. The locomotion-stimulating activity of laminin resides in the elastase digestion fragment E8, part of the laminin long arm, while the E1-4 fragment containing the three short arms is inactive. Myoblasts moved poorly over fibronectin irrespective of whether high, intermediate, or low coating concentrations were used (approximately 5,000- approximately 10 fmol cm-2). In contrast, the locomotory responses both to laminin and to E8 peaked sharply at coating concentrations approximately 20-50 fmol cm-2 and decreased at higher concentrations. This response corresponds to that expected for a haptotactic stimulant. When cells locomoted over a mixed substrate of laminin and fibronectin, the fibronectin effects appeared to predominate. The cytoskeleton has been implicated in many cellular motile processes. Within 6 h on fibronectin many cells expressed vinculin-containing focal contacts, elaborated stress fibers and had periodically organized alpha actinin, whereas on laminin, most cells showed diffuse vinculin and alpha actinin and a fine meshlike actin cytoskeleton. We conclude that the poor locomotion of cells over fibronectin is because of the cytoskeletal stabilization it induces.