Distribution of prosaposin in the rat nervous system
Distribution of prosaposin in the rat nervous system
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DOI：
10.1007/s00441-007-0464-9
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发表时间：
2007-11-01
影响因子：
3.6
通讯作者：
Matsuda, Seiji
中科院分区：
文献类型：
--
作者：
Hosoda, Yoshiki;Miyawaki, Kyojy;Matsuda, Seiji
鞘脂激活蛋白原是溶酶体水解酶的四种鞘脂激活蛋白（鞘脂激活蛋白A、B、C和D）的前体，在神经系统和肌肉中含量丰富。除了其作为溶酶体中鞘脂激活蛋白的前体的作用外，当外源性供应时，完整的鞘脂激活蛋白原在体内或体外具有神经营养作用。我们研究了saposin原在中枢和外周神经系统中的分布及其细胞内分布。使用与鞘脂激活蛋白原交叉反应但不与鞘脂激活蛋白A、B或C交叉反应的单特异性抗鞘脂激活蛋白D抗体，免疫印迹实验表明中枢和外周神经系统都表达未加工的鞘脂激活蛋白原和少量鞘脂激活蛋白D。使用抗saposin D抗体，我们证明了saposin原在中枢和外周神经系统的几乎所有神经元中都丰富，包括自主神经以及运动和感觉神经。免疫电子显微镜使用双重染色antisaposin D和anticathepsin D抗体表现出强烈的saposin主要在溶酶体颗粒在中枢和外周神经系统的神经元的免疫反应性。在这些相同的神经元中观察到saposin原mRNA的表达，使用原位杂交检测。我们的研究结果表明，saposin原是合成无处不在的神经元的中枢和外周神经系统。
Prosaposin is the precursor of four sphingolipid activator proteins (saposins A, B, C, and D) for lysosomal hydrolases and is abundant in the nervous system and muscle. In addition to its role as a precursor of saposins in lysosomes, intact prosaposin has neurotrophic effects in vivo or in vitro when supplied exogenously. We examined the distribution of prosaposin in the central and peripheral nervous systems and its intracellular distribution. Using a monospecific antisaposin D antibody that crossreacts with prosaposin but not with saposins A, B, or C, immunoblot experiments showed that both the central and peripheral nervous systems express unprocessed prosaposin and little saposin D. Using the antisaposin D antibodies, we demonstrated that prosaposin is abundant in almost all neurons of both the central and peripheral nervous systems, including autonomic nerves, as well as motor and sensory nerves. Immunoelectron microscopy using double staining with antisaposin D and anticathepsin D antibodies showed strong prosaposin immunoreactivity mainly in the lysosomal granules in the neurons in both the central and peripheral nervous systems. The expression of prosaposin mRNA, examined using in situ hybridization, was observed in these same neurons. Our results suggest that prosaposin is synthesized ubiquitously in neurons of both the central and peripheral nervous systems.