Chronic cerebral hypoperfusion in rats causes proteasome dysfunction and aggregation of ubiquitinated proteins
Chronic cerebral hypoperfusion in rats causes proteasome dysfunction and aggregation of ubiquitinated proteins
复制标题
大鼠慢性脑灌注不足导致蛋白酶体功能障碍和泛素化蛋白聚集
DOI：
10.1016/j.brainres.2010.12.030
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发表时间：
2011-02-16
期刊：
影响因子：
2.9
通讯作者：
Lu, Yang
中科院分区：
文献类型：
--
作者：
Hai, Jian;Lin, Qi;Lu, Yang
异常蛋白质聚集体的沉积是几种神经退行性疾病的特征。我们采用大鼠模型研究慢性脑灌注不足（CCH）是否诱导蛋白酶体功能障碍和泛素化蛋白和聚集体在中枢神经系统中的积累。通过乙醇磷钨酸（EPTA）电子显微镜（EM）、免疫金EM、激光扫描共聚焦显微镜和Western印迹分析蛋白质聚集。通过肽酶活性测定研究蛋白酶体肽酶活性。EPTA电镜和免疫金电镜显示，CCH可导致大鼠海马CA 1区神经元内蛋白聚集体的聚集。高分辨率共聚焦显微镜显示存在泛素阳性蛋白聚集体周围的核和沿着树突。Western blotting结果显示，CCH大鼠海马区游离泛素水平显著降低，泛素化蛋白水平显著升高。直接活性测量显示，在大鼠海马区的蛋白酶体肽酶活性下降后，CCH诱导。这些数据表明，CCH后蛋白酶体活性降低可能会损害通过泛素-蛋白酶体途径去除异常折叠的蛋白质，导致可能导致神经退行性变的潜在毒性蛋白质聚集体的积累。(C)2010 Elsevier B. V.保留所有权利。
The deposition of abnormal protein aggregates is a feature of several neurodegenerative diseases. We have employed a rat model to investigate whether chronic cerebral hypoperfusion (CCH) induces proteasome dysfunction and the accumulation of ubiquitinated proteins and aggregates in the CNS. Protein aggregation was analyzed by ethanolic phosphotungstic acid (EPTA) electron microscopy (EM), immunogold EM, laser-scanning confocal microscopy, and Western blotting. Proteasome peptidase activity was studied by peptidase activity assays. EPTA EM and immunogold EM revealed that CCH led to the accumulation of protein aggregates in rat hippocampal CA1 neurons. High-resolution confocal microscopy demonstrated the presence of ubiquitin-positive protein aggregates surrounding nuclei and along dendrites. Western blotting revealed that levels of free ubiquitin were significantly reduced and that levels of ubiquitinated proteins were markedly increased in the hippocampus of CCH rats. Direct activity measurements revealed that proteasome peptidase activity in the hippocampal region of rats was decreased after CCH induction. These data suggest that reduced proteasome activity following CCH could impair the removal of abnormally folded proteins via the ubiquitin-proteasome pathway, leading to the accumulation of potentially toxic protein aggregates that could contribute to neurodegeneration. (C) 2010 Elsevier B.V. All rights reserved.