Synaptotagmin, a synaptic vesicle protein, is present in human cerebrospinal fluid - A new biochemical marker for synaptic pathology in Alzheimer disease?
Synaptotagmin, a synaptic vesicle protein, is present in human cerebrospinal fluid - A new biochemical marker for synaptic pathology in Alzheimer disease?
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DOI：
10.1007/bf02815094
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发表时间：
1996-02-01
期刊：
影响因子：
--
通讯作者：
Blennow, K
中科院分区：
文献类型：
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作者：
Davidsson, P;Jahn, R;Blennow, K
使用一种新的方法，包括亲和色谱，反相色谱，化学发光免疫印迹，我们已经首次能够证明一个小的突触囊泡蛋白，突触结合蛋白I，在脑脊液（CSF）。另外两个小的突触囊泡蛋白，rab 3a和突触素，没有检测到。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）测定，CSF-突触结合蛋白的近似分子量为65 kDa。脑脊液突触结合蛋白进一步表征的高效毛细管电泳（HPCE）显示一个单一的峰。这些发现支持整个突触结合蛋白分子存在于CSF中，没有显著的蛋白水解降解。高速离心后的CSF，突触结合蛋白被专门发现在上清液中，这表明突触结合蛋白是存在于CSF中作为一种游离蛋白，而不是作为突触囊泡的成分。在一项初步研究中，我们发现与年龄匹配的健康个体相比，早发性阿尔茨海默病（EAD）患者的CSF突触结合蛋白显著减少。为了阐明这一发现的生物学相关性，我们还定量了脑组织中的突触结合蛋白。在EAD的海马和额叶皮质中发现突触结合蛋白的显著减少，这表明在脑中突触结合蛋白的减少之后伴随着CSF的减少。脑脊液突触结合蛋白的分析可能为研究人脑中突触功能和病理提供一种工具。
Using a novel approach, including affinity chromatography, reversed-phase chromatography, and chemiluminescence immuno-blotting, we have for the first time been able to demonstrate one of the small synaptic vesicle proteins, synaptotagmin I, in cerebrospinal fluid (CSF). Two other small synaptic vesicle proteins, rab3a and synaptophysin, were not detectable. The approximate molecular weight of CSF-synaptotagmin was 65 kDa, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Further characterization of CSF synaptotagmin by high-performance capillary electrophoresis (HPCE) showed a single peak. These findings support that the whole synaptotagmin molecule is present in CSF, without significant proteolytic degradation. After high-speed centrifugation of CSF, synaptotagmin was exclusively found in the supernatant, suggesting that synaptotagmin is present in CSF as a free protein, and not as a constituent of synaptic vesicles. In a preliminary study, we found a marked reduction of CSF synaptotagmin in patients with early onset Alzheimer disease (EAD) as compared with age-matched healthy individuals. To elucidate the biological relevance of this finding, we also quantified synaptotagmin in brain tissue. A marked reduction in synaptotagmin was found both in the hippocampus and frontal cortex of EAD, suggesting that a decrease in synaptotagmin in the brain is followed by a concomitant decrease in the CSF. Analysis of CSF synaptotagmin might provide a tool to study synaptic function and pathology in the human brain.