Czirok Andras, Zach Julia, Kozel Beth A, Mecham Robert P, Davis Elaine C, Rongish Brenda J
Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
J Cell Physiol. 2006 Apr;207(1):97-106. doi: 10.1002/jcp.20573.
Elastic fibers are responsible for the extensibility and resilience of many vertebrate tissues, and improperly assembled elastic fibers are implicated in a number of human diseases. It was recently demonstrated that in vitro, cells first secrete tropoelastin into a punctate pattern of globules. To study the dynamics of macroassembly, that is, the assembly of the secreted tropoelastin globules into elastic fibers, we utilized long-term time-lapse immunofluorescence imaging and a tropoelastin p Timer fusion protein, which shifts its fluorescence spectrum over time. Pulse-chase immunolabeling of the fibroblast-like RFL-6 cells demonstrates that tropoelastin globules aggregate in a hierarchical manner, creating progressively larger fibrillar structures. By analyzing the correlation between cell and extracellular matrix movements, we show that both the aggregation process and shaping the aggregates into fibrillar form is coupled to cell motion. We also show that the motion of non-adjacent cells becomes more coordinated as the physical size of elastin-containing aggregates increases. Our data imply that the formation of elastic fibers involves the concerted action and motility of multiple cells.
弹性纤维负责许多脊椎动物组织的伸展性和弹性，而弹性纤维组装不当与多种人类疾病有关。最近有研究表明，在体外，细胞首先将原弹性蛋白分泌成点状的小球。为了研究大分子组装的动力学，即分泌的原弹性蛋白小球组装成弹性纤维的过程，我们利用了长期延时免疫荧光成像技术和一种原弹性蛋白pTimer融合蛋白，该蛋白的荧光光谱会随时间发生变化。对成纤维样RFL-6细胞进行脉冲追踪免疫标记表明，原弹性蛋白小球以分级方式聚集，形成逐渐增大的纤维状结构。通过分析细胞与细胞外基质运动之间的相关性，我们发现聚集过程以及将聚集体塑造成纤维状的过程都与细胞运动相关。我们还表明，随着含弹性蛋白聚集体的物理尺寸增加，非相邻细胞的运动变得更加协调。我们的数据表明，弹性纤维的形成涉及多个细胞的协同作用和运动。
