Moskowitz P F, Smith R, Pickett J, Frankfurter A, Oblinger M M
Department of Cell Biology and Anatomy, Chicago Medical School, North Chicago, Illinois 60064.
J Neurosci Res. 1993 Jan;34(1):129-34. doi: 10.1002/jnr.490340113.
The effect of peripheral axotomy on the expression of the class III beta-tubulin gene in adult dorsal root ganglion (DRG) neurons was examined. Of the 5 isotypic classes of beta-tubulin expressed in the mammalian nervous system, only the class III beta-tubulin is neuron specific. While information about the expression of several of the tubulin genes during neuronal development and regeneration has become available recently, very little is known about the expression of beta III-tubulin during axonal regeneration. To explore this issue, we examined axotomy-induced changes in beta III-tubulin mRNA levels in adult rat lumbar dorsal root ganglion (DRG) neurons at different times (1-28 days) after unilateral sciatic nerve crush using northern blotting of total RNA and quantitative in situ hybridization. These studies showed an initial decrease in beta III-tubulin mRNA levels in axotomized DRG neurons as compared to contralateral controls at 1 day after injury followed by robust increases in beta III-tubulin mRNA levels relative to contralateral controls from 1 to 4 weeks after injury. We postulate that beta III-tubulin may play an essential role in axonal growth because of its unique neuron-specific pattern of expression and its substantial increase in neurons that have been stimulated to regrow their axons.
研究了外周轴突切断术对成年背根神经节（DRG）神经元中III类β-微管蛋白基因表达的影响。在哺乳动物神经系统中表达的5种β-微管蛋白同型类别中，只有III类β-微管蛋白是神经元特异性的。虽然最近已经获得了一些关于微管蛋白基因在神经元发育和再生过程中表达的信息，但对于轴突再生过程中βIII-微管蛋白的表达却知之甚少。为了探讨这个问题，我们使用总RNA的Northern印迹法和定量原位杂交技术，检测了成年大鼠腰段背根神经节（DRG）神经元在单侧坐骨神经挤压后不同时间（1 - 28天）轴突切断术诱导的βIII-微管蛋白mRNA水平的变化。这些研究表明，与对侧对照相比，损伤后1天，轴突切断的DRG神经元中βIII-微管蛋白mRNA水平最初下降，随后在损伤后1至4周，相对于对侧对照，βIII-微管蛋白mRNA水平显著增加。我们推测，βIII-微管蛋白可能在轴突生长中起重要作用，因为其独特的神经元特异性表达模式以及在被刺激重新长出轴突的神经元中大量增加。
