Rovensky Y A, Domnina L V, Ivanova O Y, Vasiliev J M
Cancer Research Center of the Russian Federation, Moscow, Russia.
J Cell Sci. 1999 Apr;112 ( Pt 8):1273-82. doi: 10.1242/jcs.112.8.1273.
Behaviour of epitheliocytes and fibroblasts on special discontinuous substrata (metallic grids with square openings of 45x45 microm2) was examined in order to compare the ability of these cells to spread in two mutually perpendicular directions and to stretch over the void spaces. Two cell types with typical fibroblastic morphology, the AGO 1523 line of human foreskin fibroblasts and secondary cultures of mouse embryo fibroblasts, and three cell types with typical epithelial morphology, primary mouse hepatocytes, the IAR-2 line of rat liver cells and the MDCK line of canine kidney epithelial cells (clone 20) were used. We also examined the epitheliocytes (MDCK cells, clone 20) transformed to fibroblast-like morphology by treatment with hepatocyte growth factor/scatter factor (HGF/SF). Time-lapse video microscopy, scanning electron microscopy and immunofluorescence microscopy were used to examine cell reorganizations at various stages of spreading. It was found that early stages of spreading of fibroblasts and epitheliocytes were similar: the cell spread along two bars, perpendicular to each other (bar and crossbar), with the formation of a small triangular lamellar cytoplasm stretched over the opening. Later central parts of the bodies of the fibroblasts retracted from the bars so that the cells remained attached only by their polar lamellae. Successive expansions and partial retractions of these lamellae led to elongation of the cell body crossing several openings of the grid. Epitheliocytes, in contrast to fibroblasts, at the late stages of spreading did not retract their bodies and did not contract polar lamellae. As a result, their central lamellae stretched progressively over the openings. As a result of the treatment of MDCK epitheliocytes with HGF/SF the behaviour of the cells on the grids became similar to that of fibroblasts. It is suggested that these distinct spreading patterns of epitheliocytes and fibroblasts are due to the type-specific differences in the actin-myosin cortex. Experiments with microtubule-specific drugs, colcemid and taxol, indicate that the organization of this cortex is under microtubular control.
为了比较上皮细胞和成纤维细胞在两个相互垂直方向上伸展以及在空隙处拉伸的能力，研究了这些细胞在特殊的不连续基质（具有45×45微米²方形开口的金属网格）上的行为。使用了两种具有典型成纤维细胞形态的细胞类型，即人包皮成纤维细胞AGO 1523系和小鼠胚胎成纤维细胞的传代培养物，以及三种具有典型上皮形态的细胞类型，即原代小鼠肝细胞、大鼠肝细胞IAR - 2系和犬肾上皮细胞MDCK系（克隆20）。我们还研究了用肝细胞生长因子/分散因子（HGF/SF）处理后转变为成纤维细胞样形态的上皮细胞（MDCK细胞，克隆20）。使用延时视频显微镜、扫描电子显微镜和免疫荧光显微镜来检查细胞在伸展各个阶段的重组情况。结果发现，成纤维细胞和上皮细胞伸展的早期阶段相似：细胞沿着两条相互垂直的杆（横杆和交叉杆）伸展，形成一个小的三角形片状细胞质，伸展在开口上方。后来，成纤维细胞体的中央部分从杆上缩回，使得细胞仅通过其极性薄片附着。这些薄片的连续扩张和部分缩回导致细胞体伸长，穿过网格的几个开口。与成纤维细胞相反（对比成纤维细胞），上皮细胞在伸展后期不会缩回其身体，也不会收缩极性薄片。结果，它们的中央薄片逐渐伸展在开口上方。用HGF/SF处理MDCK上皮细胞后，细胞在网格上的行为变得与成纤维细胞相似。有人认为，上皮细胞和成纤维细胞这些不同的伸展模式是由于肌动蛋白 - 肌球蛋白皮质的类型特异性差异所致。用微管特异性药物秋水仙酰胺和紫杉醇进行的实验表明，这种皮质的组织受微管控制。
