MECHANICS OF FIBROBLAST LOCOMOTION - QUANTITATIVE-ANALYSIS OF FORCES AND MOTIONS AT THE LEADING LAMELLAS OF FIBROBLASTS
MECHANICS OF FIBROBLAST LOCOMOTION - QUANTITATIVE-ANALYSIS OF FORCES AND MOTIONS AT THE LEADING LAMELLAS OF FIBROBLASTS
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DOI：
10.1083/jcb.111.6.2513
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发表时间：
1990-12-01
影响因子：
7.8
通讯作者：
ELSON, EL
中科院分区：
文献类型：
--
作者：
FELDER, S;ELSON, EL
通过微分干涉对比显微镜和数字视频增强技术，对原代鸡胚心脏成纤维细胞前缘的片状伪足和皱褶中的运动、运动和力进行了表征。细胞边缘的初始延伸，形成一个薄的，平面lamellipodium平行于基板表面进行了分析，在两个维度的时间和空间分辨率分别为3秒和0.2 μ m。一个扩展开始和结束与简短的，快速的加速和减速分开的一个长时间的几乎恒定的速度在4-7 μ m/min的范围内。扩展和回缩随机开始随着时间的推移。如光学切片显微镜所示，延长的板状伪足在其尖端后2-4 μ m的铰链点处急剧向上弯曲形成皱褶。令人惊讶的是，褶边在向上弯曲后继续以相同的平均速度增长。它们在垂直横截面上保持直的形状，表明皱褶是机械刚性的。通过将薄的石英鱼杆探针推到距皱褶基部7-10 μ m的顶端，朝向或远离细胞中心，测量使这些细胞和BC 3 H1细胞的皱褶弯曲所需的力。通过测量由视频显微镜监测的探针的弯曲来确定力。通常情况下，探针迫使褶边在其底部的一个明显的铰链周围以弧形刚性摆动，并且当探针被移除时，褶边迅速且几乎完全恢复其形状。因此，褶边看起来相对较硬，并且与细胞体不同，其抵抗力弹性大于粘性。当朝向或远离细胞中心推动时，两种类型细胞上的皱褶抵抗在其尖端处的15-30 μ-dyn/μ-m位移力的弯曲。细胞运动机制的意见的意义进行了讨论。
Shapes, motions, and forces developed in lamellipodia and ruffles at the leading edges of primary chick embryo heart fibroblasts were characterized by differential interference contrast microscopy and digital video enhancement techniques. The initial extension of the cell edge to form a thin, planar lamellipodium parallel to the substrate surface was analyzed in two dimensions with temporal and spatial resolution of 3 s and 0.2-mu-m, respectively. An extension begins and ends with brief, rapid acceleration and deceleration separated by a long period of nearly constant velocity in the range of 4-7-mu-m/min. Extensions and retractions were initiated randomly over time. As demonstrated by optical sectioning microscopy, the extended lamellipodia formed ruffles by sharply bending upward at hinge points 2-4-mu-m behind their tips. Surprisingly, ruffles continued to grow in length at the same average rate after bending upward. They maintained a straight shape in vertical cross section, suggesting the ruffles were mechanically stiff.The forces required to bend ruffles of these cells and of BC3H1 cells were measured by pushing a thin quartz fishpole probe against the tip of a ruffle 7-10-mu-m from its base either toward or away from the center of the cell. Force was determined by measuring the bending of the probe monitored by video microscopy. Typically the probe forced the ruffle to swing rigidly in an arc about an apparent hinge at is base, and ruffles rapidly, and almost completely, recovered their shape when the probe was removed. Hence, ruffles appeared to be relatively stiff and to resist bending with forces more elastic than viscous, unlike the cell body. Ruffles on both types of cells resisted bending with forces of 15-30-mu-dyn/mu-m of displacement at their tips when pushed toward or away from the cell center. The significance of the observations for mechanisms of cell locomotion is discussed.