INHIBITION OF FORMATION OF FILOPODIA AFTER AXOTOMY BY INHIBITORS OF PROTEIN-TYROSINE KINASES
INHIBITION OF FORMATION OF FILOPODIA AFTER AXOTOMY BY INHIBITORS OF PROTEIN-TYROSINE KINASES
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DOI：
10.1002/neu.480270409
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发表时间：
1995-08-01
期刊：
影响因子：
--
通讯作者：
WU, DY
中科院分区：
文献类型：
--
作者：
GOLDBERG, DJ;WU, DY
生长锥的能动突起--丝状伪足、面纱和板状伪足--的活动对于神经元过程的定向生长是必不可少的。这些突起的形成的调节还没有很好地理解。许多丝状伪足和面纱或板状伪足在培养物中的轴突横切的几分钟内形成，作为再生神经突的生长锥的初始组分。因此，轴突切开术为分析这些突起的形成提供了一个强大而可靠的协议。我们评估了蛋白质磷酸化在调节蛋白活性中的作用。蛋白激酶的抑制剂测定，只有蛋白酪氨酸激酶的抑制剂染料木素，laviustin A，除草霉素A，和erbstatin类似物抑制突起的形成，通过高放大倍数视频显微镜评估。这些药物并不通过防止轴突的重新密封而起作用，如从视觉检查和通过染料木黄酮或熏衣草素在重新密封后应用时防止丝状伪足形成的未受损的有效性所证明的。蛋白酪氨酸激酶的抑制不仅阻止了肌动蛋白为基础的突起的形成，但也引起了恶化的肌动蛋白网络的基础上的膨胀面积预先存在的生长锥。与参与蛋白酪氨酸磷酸化的产生的膨胀结构一致，免疫细胞化学显示，聚集的磷酸酪氨酸出现在边缘的轴突，从突起出现后不久轴突切断。这些结果表明，蛋白酪氨酸磷酸化的肌动蛋白为基础的膨胀结构的形成和维持的作用。(C)1995年，John Wiley and Sons，Inc.
The activity of motile protrusions of the growth cone-filopodia, veils, and lamellipodia-is essential for directed growth of a neuronal process. The regulation of the formation of these protrusions is not well understood. Numerous filopodia and veils or lamellipodia form within minutes of transection of an Aplysia axon in culture, as the initial components of growth cones of regenerating neurites. Axotomy, therefore, provides a robust and reliable protocol for analyzing the formation of these protrusions. We evaluated the involvement of protein phosphorylation in the regulation of protrusive activity. Of the inhibitors of protein kinases assayed, only the inhibitors of protein tyrosine kinases-genistein, lavendustin A, herbimycin A, and erbstatin analogue-suppressed the formation of protrusions, as assessed by high magnification video microscopy. These drugs did not work by preventing resealing of the axon, as evident from visual inspection and by the unimpaired effectiveness of genistein or lavendustin in preventing formation of filopodia when applied after resealing. Inhibition of protein tyrosine kinases not only prevented the formation of actin-based protrusions, but also caused deterioration of the actin network underlying the protrusive area of preexisting growth cones. Consistent with an involvement of protein tyrosine phosphorylation in the generation of protrusive structures, immunocytochemistry revealed that aggregates of phosphotyrosine appeared at the margins of the axon, from which protrusions emerge shortly after axotomy. These results suggest a role for protein tyrosine phosphorylation in the formation and maintenance of actin-based protrusive structures. (C) 1995 John Wiley and Sons, Inc.