Axon-dominant localization of cell-surface cholesterol in cultured hippocampal neurons and its disappearance in Niemann-Pick type C model cells
Axon-dominant localization of cell-surface cholesterol in cultured hippocampal neurons and its disappearance in Niemann-Pick type C model cells
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DOI：
10.1111/j.1460-9568.2004.03677.x
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发表时间：
2004-10-01
影响因子：
3.4
通讯作者：
Okamoto, K
中科院分区：
文献类型：
--
作者：
Tashiro, Y;Yamazaki, T;Okamoto, K
越来越多的证据表明胆固醇在维持神经元功能中的重要作用。特别是，人们对称为脂筏的富含胆固醇的微区的作用给予了很大的关注。然而，胆固醇在神经元上的分布尚不清楚。在这里，我们研究了本地化的胆固醇在培养的大鼠海马神经元，使用菲律宾和一种新的胆固醇结合剂BCtheta。在我们的培养系统中，BCtheta仅检测细胞表面胆固醇，而菲律宾染色细胞内和细胞表面胆固醇。BCtheta染色以成熟依赖的方式出现，并显示在完全成熟的神经元中细胞表面胆固醇的轴突优势分布。轴突上的一部分胆固醇在4 ℃时对洗涤剂有抵抗力，因此可能参与脂筏。有趣的是，由2类两亲物诱导的Niemann-Pick C型模型神经元失去了细胞表面而不是细胞内胆固醇染色。C型尼曼-皮克病是由细胞内胆固醇转运的破坏引起的，并且已知其诱导脑中的神经变性，伴随着神经元缠结的形成。我们的观察表明，细胞表面胆固醇在维持功能性轴突膜中的重要作用，并表明所观察到的轴突表面胆固醇缺陷可能导致神经退行性变。
There is growing evidence showing the important role of cholesterol in maintaining neuronal function. In particular, much attention has been paid to the role of the cholesterol-rich microdomains called lipid rafts. However, the cholesterol distribution on neurons is not clear. Here, we investigated localization of cholesterol in cultured rat hippocampal neurons, using filipin and a novel cholesterol-binding reagent BCtheta. In our culture system, BCtheta detects only cell-surface cholesterol, whereas filipin stains both intracellular and cell-surface cholesterol. BCtheta staining appeared visible in a maturation-dependent manner and showed axon-dominant distribution of cell-surface cholesterol in fully matured neurons. A part of this cholesterol on axons was resistant to detergents at 4degreesC, and thus might be involved in lipid rafts. Interestingly, Niemann-Pick type C model neurons induced by class 2 amphiphiles lost the cell-surface but not the intracellular cholesterol staining. Niemann-Pick type C disease is caused by the disruption of intracellular cholesterol transport and is known to induce neurodegeneration in brains accompanied by formation of neurofibrillary tangles. Our observations suggest the important role of cell-surface cholesterol in maintaining a functional axonal membrane and indicate that the observed defect in axonal surface cholesterol might lead to neurodegeneration.