Localization of the membrane-anchored MMP-regulator RECK at the neuromuscular junctions
Localization of the membrane-anchored MMP-regulator RECK at the neuromuscular junctions
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DOI：
10.1111/j.1471-4159.2007.04977.x
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发表时间：
2008-01-01
影响因子：
4.7
通讯作者：
Noda, Makoto
中科院分区：
文献类型：
--
作者：
Kawashima, Satoshi;Imamura, Yukio;Noda, Makoto
胚胎18.5天时，小鼠骨骼肌的神经肌肉接头(NMJ)出现神经与烟碱型乙酰胆碱受体簇的结合和突触后膜的内陷(即次级皱折形成)。在发育的这个阶段找到在NMJ表达的分子可能有助于阐明神经末梢和肌肉纤维之间的强烈联系是如何建立的。免疫组织化学分析表明，膜锚定的基质金属蛋白酶调节因子RECK在成年骨骼肌的NMJ处有丰富的表达。共聚焦显微镜和电子显微镜下可见RECK免疫反应阳性细胞定位于肌肉的次级皱折和突触下细胞间。时程研究表明，在胚胎18.5天左右及以后，RECK免疫反应与隔膜中的NMJ相关。这些发现，连同已知的RECK的特性，支持了RECK参与NMJ形成和/或维持的假设，可能是通过保护细胞外成分，如突触基板，防止蛋白质降解。
Nerve apposition on nicotinic acetylcholine receptor clusters and invagination of the post-synaptic membrane (i.e. secondary fold formation) occur by embryonic day 18.5 at the neuromuscular junctions (NMJs) in mouse skeletal muscles. Finding the molecules expressed at the NMJ at this stage of development may help elucidating how the strong linkage between a nerve terminal and a muscle fiber is established. Immunohistochemical analyses indicated that the membrane-anchored matrix metalloproteinase regulator RECK was enriched at the NMJ in adult skeletal muscles. Confocal and electron microscopy revealed the localization of RECK immunoreactivity in secondary folds and subsynaptic intracellular compartments in muscles. Time course studies indicated that RECK immunoreactivity becomes associated with the NMJ in the diaphragm at around embryonic day 18.5 and thereafter. These findings, together with known properties of RECK, support the hypothesis that RECK participates in NMJ formation and/or maintenance, possibly by protecting extracellular components, such as synaptic basal laminae, from proteolytic degradation.