Roles of microtubules, cell polarity and adhesion in electric-field-mediated motility of 3T3 fibroblasts
Roles of microtubules, cell polarity and adhesion in electric-field-mediated motility of 3T3 fibroblasts
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DOI：
10.1242/jcs.00986
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发表时间：
2004-03-15
影响因子：
4
通讯作者：
Bulinski, JC
中科院分区：
文献类型：
--
作者：
Finkelstein, E;Chang, W;Bulinski, JC
直流电场调节许多细胞类型的运动性（流原性）。在3T3成纤维细胞中，电场增加了运动细胞的比例、速度和阴极方向性。类似于成纤维细胞的自发迁移，我们最初假设微管成分的重新定向调节了流性。然而，具有完整微管的细胞并没有在磁场中重新定位，而没有微管的细胞仍然迁移，尽管速度很慢，从而反驳了该假设。接下来，我们提出，在受伤并置于电场中的单层中，微管组织中心的重新定向和稳定的、去甲基化的微管向伤口边缘移动是必要的和/或充分的。这一假设被否定了，因为电场暴露介导了无定向、面向阴极的细胞的迁移和定向、面向阳极的细胞的迁移。这使我们提出消融微管去酪氨酸不会影响趋流性。令人惊讶的是，阻止微管去酪氨酸会增加运动速度，这表明去酪氨酸抑制了流性。微管可能会增强恒流过程中的粘附/去粘附重塑；因此，电场可能更有效地调节附着在基质上的细胞的运动性。与这一假设一致，未完全扩散的细胞比完全扩散的细胞迁移得更快。此外，过表达PAK4（一种cdc42激活的激酶，可降低粘附性）可提高趋流速度，而过表达PAK4则会降低趋流速度。因此，电场通过微管和粘附成分的参与介导成纤维细胞的迁移，但它们的参与不同于自发运动。
Direct-current electric fields mediate motility (galvanotaxis) of many cell types. In 3T3 fibroblasts, electric fields increased the proportion, speed and cathodal directionality of motile cells. Analogous to fibroblasts' spontaneous migration, we initially hypothesized that reorientation of microtubule components modulates galvanotaxis. However, cells with intact microtubules did not reorient them in the field and cells without microtubules still migrated, albeit slowly, thus disproving the hypothesis. We next proposed that, in monolayers wounded and placed in an electric field, reorientation of microtubule organizing centers and stable, detyrosinated microtubules towards the wound edge is necessary and/or sufficient for migration. This hypothesis was negated because field exposure mediated migration of unoriented, cathode-facing cells and curtailed migration of oriented, anode-facing cells. This led us to propose that ablating microtubule detyrosination would not affect galvanotaxis. Surprisingly, preventing microtublule detyrosination increased motility speed, suggesting that detyrosination inhibits galvanotaxis. Microtubules might enhance adhesion/de-adhesion remodeling during galvanotaxis; thus, electric fields might more effectively mediate motility of cells poorly or dynamically attached to substrata. Consistent with this hypothesis, incompletely spread cells migrated more rapidly than fully spread cells. Also, overexpression of PAK4, a Cdc42-activated kinase that decreases adhesion, enhanced galvanotaxis speed, whereas its lack decreased speed. Thus, electric fields mediate fibroblast migration via participation of microtubules and adhesive components, but their participation differs from that during spontaneous motility.