New insights into peripherin expression in cochlear neurons
New insights into peripherin expression in cochlear neurons
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DOI：
10.1016/j.neuroscience.2007.08.032
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发表时间：
2007-11-30
期刊：
影响因子：
3.3
通讯作者：
Malgrange, B.
中科院分区：
文献类型：
--
作者：
Lallemend, F.;Vandenbosch, R.;Malgrange, B.
外周蛋白是一种在外周和肠内神经元中表达的中间丝蛋白。在耳蜗神经系统中，外周蛋白的表达已被广泛用作一种分化标志物，通过优先标记成年期II型神经元群体，但尚未了解其功能。由于外周蛋白的表达在时间上与其他系统的轴突延伸过程和神经纤维再生过程有关，因此确定耳蜗神经元中的外周蛋白表达是一种静态表型特征，还是在神经损伤后容易发生改变，是一项有趣的研究。在本研究中，我们首先比较了大鼠耳蜗上皮外周蛋白和β ii -微管蛋白从胚胎晚期到成年的表达模式。出生前所有耳蜗神经元均可见这两种蛋白的染色。出生后2 - 3天，外周蛋白的表达逐渐局限于II型神经元群体及其突起。相比之下，从出生后10天开始，虽然所有耳蜗神经元的突起中仍有β - ii -微管蛋白的表达，但只有I型群体的细胞体中有β - ii -微管蛋白的免疫反应性。接下来，我们利用器官型外植体模型研究了外周蛋白在切除耳蜗神经元中的表达。外周蛋白令人惊讶地在绝大多数神经细胞中重新表达。同时，研究了β ii -微管蛋白和外周蛋白在耳蜗神经元游离培养物中的表达和定位。两种蛋白沿整个神经元长度分布，但呈互补分布，特别是在突起内。此外，外周蛋白的免疫反应性在生长锥体中仍然丰富，而β ii -微管蛋白的免疫反应性在该细胞室中下降。我们的发现与外周素在耳蜗神经元及其在发育和再生过程中的投影中起重要结构作用的模型一致，这与在神经元再生过程中经常被重新激活的发育调节因子的假设是一致的。(c) 2007 IBRO。Elsevier Ltd.出版。版权所有。
Peripherin is an intermediate filament protein that is expressed in peripheral and enteric neurons. In the cochlear nervous system, peripherin expression has been extensively used as a differentiation marker by preferentially labeling the type II neuronal population at adulthood, but yet without knowing its function. Since the expression of peripherin has been associated in time with the process of axonal extension and during regeneration of nerve fibers in other systems, it was of interest to determine whether peripherin expression in cochlear neurons was a static phenotypic trait or rather prone to modifications following nerve injury. In the present study, we first compared the expression pattern of peripherin and betaIII-tubulin from late embryonic stages to the adult in rat cochlea. The staining for both proteins was seen before birth within all cochlear neurons. By birth, and for 2 or 3 days, peripherin expression was gradually restricted to the type II neuronal population and their projections. In contrast, from postnatal day (P) 10 onwards, while the expression of betaIII-tubulin was still found in projections of all cochlear neurons, only the type I population had betaIII-tubulin immunoreactivity in their cell bodies. We next investigated the expression of peripherin in axotomized cochlear neurons using an organotypic explant model. Peripherin expression was surprisingly re-expressed in a vast majority of neurons after axotomy. In parallel, the expression and localization of betaIII-tubulin and peripherin in dissociated cultures of cochlear neurons were studied. Both proteins were distributed along the entire neuronal length but exhibited complementary distribution, especially within the projections. Moreover, peripherin immunoreactivity was still abundant in the growth cone, whereas that of betaIII-tubulin was decreasing at this compartment. Our findings are consistent with a model in which peripherin plays an important structural role in cochlear neurons and their projections during both development and regenerative processes and which is compatible with the assumption that frequently developmentally regulated factors are reactivated during neuronal regeneration. (c) 2007 IBRO. Published by Elsevier Ltd. All rights reserved.