Induction of microtubule-associated protein 1B expression in Schwann cells during nerve regeneration
Induction of microtubule-associated protein 1B expression in Schwann cells during nerve regeneration
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DOI：
10.1016/s0006-8993(99)01148-8
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发表时间：
1999-03-27
期刊：
影响因子：
2.9
通讯作者：
Fischer, I
中科院分区：
文献类型：
--
作者：
Ma, DL;Chow, S;Fischer, I
微管相关蛋白1B（MAP 1B）在神经系统发育期间以高水平表达，并且主要定位于神经元中，而特异性磷酸化的MAP 1B亚型仅定位于生长的轴突中。MAP 1B的水平在成年CNS的大部分区域中下调，但在PNS的神经元和轴突中保持高水平。这项研究表明，MAP 1B的表达诱导成年雪旺细胞坐骨神经损伤和再生。高水平的mRNA和MAP 1B蛋白检测雪旺细胞与轴突切断远端残端。在培养的新生大鼠原代雪旺细胞中也观察到MAP 1B的表达。使用识别MAP 1B的N末端、中间和C末端结构域的特异性抗体通过蛋白质印迹分析进一步表征培养的施万细胞中MAP 1B蛋白的特性。所有这些抗体都检测到320-340 kDa的蛋白质，证明由雪旺细胞表达的MAP 1B与由神经元表达的MAP 1B非常相似或相同。还使用识别特异性磷酸化表位的单克隆抗体（mAb）研究了施旺细胞中MAP 1B的磷酸化。结果表明，MAP 1B在雪旺细胞中的表达表现出差异磷酸化状态，该状态被mAb 1B 6识别，但不被其他mAb识别，包括1B-P、150和RT 97，其识别生长轴突中磷酸化的MAP 1B。因此，我们的结论是，MAP 1B的表达在雪旺氏细胞在发展和轴突再生，这表明在这些细胞中的MAP 1B的发展模式是重演在成年雪旺氏细胞在早期阶段的再生和髓鞘再生受损的外周轴突。MAP 1B在雪旺细胞中的存在可能支持这些细胞的形态学变化，特别是在它们分化成髓鞘形成雪旺细胞之前形成突起。(C)1999 Elsevier Science B. V.保留所有权利。
Microtubule-associated protein 1B (MAP1B) is expressed at high levels during development of the nervous system and is localized primarily in neurons while specific phosphorylated isoforms of MAP1B are localized exclusively in growing axons. The levels of MAP1B are down regulated in most regions of the adult CNS, but remain high in neurons and axons of the PNS. This study demonstrates that the expression of MAP1B is induced in adult Schwann cells following sciatic nerve lesion and regeneration. High levels of both mRNA and the MAP1B protein were detected in Schwann cells associated with the axotomized distal stump. Expression of MAP1B was also observed in cultured primary Schwann cells from neonatal rats. The properties of the MAP1B protein in cultured Schwann cells were further characterized by Western blot analysis using specific antibodies that recognize the N-terminal, middle and C-terminal domains of MAP1B. All of these antibodies detected a protein of 320-340 kDa demonstrating that MAP1B expressed by Schwann cells is very similar, or identical, to MAP1B expressed by neurons. The phosphorylation of MAP1B in Schwann cells was also studied using monoclonal antibodies (mAb) that recognize specific phosphorylation epitopes. The results indicated that the expression of MAP1B in Schwann cells exhibited a differential phosphorylation state that was recognized by mAb 1B6 but not by other mAbs, including 1B-P, 150 and RT97, that recognize phosphorylated MAP1B in growing axons. We therefore conclude that MAP1B is expressed in Schwann cells during both development and axonal regeneration, suggesting that the developmental pattern of MAP1B in these cells is recapitulated in adult Schwann cells during the early stages of regeneration and remyelination of injured peripheral axons. The presence of MAP1B in Schwann cells may support morphological changes of these cells, Particularly the formation of processes prior to their differentiation into myelin forming Schwann cells. (C) 1999 Elsevier Science B.V. All rights reserved.