Rich A M, Hoffstein S T
J Cell Sci. 1981 Apr;48:181-91. doi: 10.1242/jcs.48.1.181.
The random migration of neutrophils under agarose as measured by the number of cells leaving the well, is enhanced when the pH or the osmolality of the medium is reduced or when microtubule agents are used. Concentrations of colchicine above 5 x 10-7 M increased the number of cells migrating and decreased the mean number of centriolar microtubules in a dose-dependent fashion from 16 to 4 per 4 micron 2 at 10-5 M. The distance that colchicine-treated neutrophils migrated from the well was not different from the control. Lowering the pH from 7.4 to 6.0 also increased random migration and decreased pericentriolar microtubules from a mean of 16 to a mean of 10. At pH 6.0, both the number of cells that migrated and the distance the cells forming the leading edge travelled from the well were increased. Since peripheral microtubules may play a greater role in cell migration than centiolar ones, we examined the numerical density of microtubules in the peripheral cytoplasm. Lowering the medium pH reduced the mean number of microtubules per 10 micron 2 from 6 to 2. Colchicine reduced micro-tubules in the same area to I. At the low pH, colchicine reduced even further the numbers of both centriole-associated and peripheral microtubules but the migration pattern was the same as that seen at pH 6.0 without colchicine. Lowering medium osmolality from 280 to 230 m-osmol increased random migration but did not affect microtubule numbers. The addition of colchicine to this system decreased microtubule numbers and increased migration even further. Conditions that enhanced neutrophil migration also affected cell shape. Whereas cells at pH 7.4 were generally fan-shaped with a broad, smooth leading edge, cells at pH 6.0 with or without colchicine were long and narrow. Neutrophils at pH 7.4 but 230 m-osmol had a scalloped edge, which often appeared thickened. This too was not altered by colchicine. The morphology of cells treated with colchicine was similar to controls except for the more frequent presence of long retraction fibres. Each of these treatments thus appears to act on a different aspect of the cell's locomotory apparatus. The mechanisms by which colchicine and lowered ph enhance migration may partially overlap since both significantly decrease peripheral microtubules. The data suggest that microtubules play a constraining role within the cell, limiting the ability of the cell to move and change direction.
通过离开孔的细胞数量来衡量，在琼脂糖下中性粒细胞的随机迁移，在培养基的pH值或渗透压降低时，或使用微管药物时会增强。秋水仙碱浓度高于5×10⁻⁷M时，会增加迁移的细胞数量，并以剂量依赖的方式使每4平方微米中心粒微管的平均数量从16根减少到10⁻⁵M时的4根。用秋水仙碱处理的中性粒细胞从孔中迁移的距离与对照组没有差异。将pH值从7.4降至6.0也会增加随机迁移，并使中心粒周围微管从平均16根减少到平均10根。在pH 6.0时，迁移的细胞数量以及形成前沿的细胞从孔中移动的距离都增加了。由于外周微管在细胞迁移中可能比中心粒微管发挥更大的作用，我们检查了外周细胞质中微管的数量密度。降低培养基pH值会使每10平方微米微管的平均数量从6根减少到2根。秋水仙碱使同一区域的微管减少到1根。在低pH值下，秋水仙碱进一步减少了与中心粒相关的微管和外周微管的数量，但迁移模式与在pH 6.0且未使用秋水仙碱时相同。将培养基渗透压从280毫渗摩尔降低到230毫渗摩尔会增加随机迁移，但不影响微管数量。向该系统中添加秋水仙碱会减少微管数量并进一步增加迁移。增强中性粒细胞迁移的条件也会影响细胞形状。pH 7.4时的细胞通常呈扇形，前沿宽阔、光滑，而pH 6.0时无论有无秋水仙碱的细胞都又长又窄。pH 7.4但渗透压为230毫渗摩尔时的中性粒细胞有锯齿状边缘，且常常看起来增厚。这也不受秋水仙碱影响。用秋水仙碱处理的细胞形态与对照组相似，只是更频繁地出现长的收缩纤维。因此，这些处理似乎都作用于细胞运动装置的不同方面。秋水仙碱和降低pH值增强迁移的机制可能部分重叠，因为两者都会显著减少外周微管。数据表明，微管在细胞内起限制作用，限制细胞移动和改变方向的能力。
