Keller H, Niggli V
Institute of Pathology, University of Bern, Switzerland.
Eur J Cell Biol. 1995 Feb;66(2):157-64.
We report that cytochalasin D (CD) is not a reliable tool to inhibit all forms of cell motility and actin polymerization in neutrophil granulocytes. In addition to the well-established effects of CD such as altered localization of F-actin, inhibition of surface ruffling, fluid pinocytosis and actin polymerization in agonist-stimulated cells, we find that in human neutrophils CD can 1) induce another type of continuous shape changes (10(-6) M and 10(-5) M CD), 2) stimulate fluid pinocytosis (10(-5) M CD), 3) increase actin polymerization (10(-5) to 10(-4) M CD) and alter the localization of F-actin and alpha-actinin (10(-6) to 10(-4) M CD). At 10(-5) M CD F-actin and alpha-actinin are preferentially located in different areas of the cell. At 10(-4) M CD actin and alpha-actinin may colocalize at the membrane but not in cytoplasmic foci. Thus, stimulation of shape changes, pinocytosis, actin polymerization and differential reorganization of the cytoskeleton occur at CD concentrations which are widely used to inhibit cell motility. The results show that CD is not a reliable tool to inhibit all movements of cells and actin polymerization in general. Shape changes, but not fluid pinocytosis and the relative redistribution of F-actin and alpha-actinin induced by 10(-5) M cytochalasin D are suppressed by 10(-5) colchicine. This indicates that also microtubules can play a role in determining neutrophil shape and movements.
我们报告称，细胞松弛素D（CD）并非抑制中性粒细胞中所有形式的细胞运动和肌动蛋白聚合的可靠工具。除了CD已确定的作用，如F-肌动蛋白定位改变、抑制激动剂刺激细胞的表面褶皱、液体胞饮作用和肌动蛋白聚合外，我们发现，在人类中性粒细胞中，CD能够：1）诱导另一种类型的持续形状变化（10⁻⁶ M和10⁻⁵ M CD）；2）刺激液体胞饮作用（10⁻⁵ M CD）；3）增加肌动蛋白聚合（10⁻⁵至10⁻⁴ M CD），并改变F-肌动蛋白和α-辅肌动蛋白的定位（10⁻⁶至10⁻⁴ M CD）。在10⁻⁵ M CD时，F-肌动蛋白和α-辅肌动蛋白优先位于细胞的不同区域。在10⁻⁴ M CD时，肌动蛋白和α-辅肌动蛋白可能在膜上共定位，但不在细胞质灶中共定位。因此，在广泛用于抑制细胞运动的CD浓度下，会出现形状变化、胞饮作用、肌动蛋白聚合的刺激以及细胞骨架的差异重组。结果表明，CD并非抑制细胞所有运动和一般肌动蛋白聚合的可靠工具。10⁻⁵ M秋水仙碱可抑制10⁻⁵ M细胞松弛素D诱导的形状变化，但不抑制液体胞饮作用以及F-肌动蛋白和α-辅肌动蛋白的相对重新分布。这表明微管在决定中性粒细胞的形状和运动中也可能发挥作用。
