Aoki Kazuko, Uchihara Toshiki, Sanjo Nobuo, Nakamura Ayako, Ikeda Kenji, Tsuchiya Kuniaki, Wakayama Yoshihiro
Department of Neuropathology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Stroke. 2003 Apr;34(4):875-80. doi: 10.1161/01.STR.0000064320.73388.C6. Epub 2003 Mar 20.
Cellular origin of apolipoprotein E (ApoE) in the human brain and its roles in physiological and pathological conditions remain to be clarified.
Immunolocalization of ApoE was investigated in a series of autopsied human brains with or without infarction. ApoE expression was also estimated on immunoblot on protein extracts from autopsied brains and a cultured neuroblastoma cell line of human origin (GOTO) subjected to an oxidative stress induced by exposure to hydrogen peroxide (0.2 mmol/L).
In addition to astrocytes and microglia, neurons and degenerated axons in and around the ischemic foci contained ApoE-like immunoreactivity, which was more intense in recent ischemic foci. Immunoblot demonstrated an increase in expression of ApoE in brain extracts from ischemic lesion, and this increase was also pronounced in the cultured neuroblastoma cell line after the stress.
Accumulation of ApoE in neurons in and around ischemic foci of the human brain is related to an increase in ApoE synthesis in neurons, as seen in cultured neuronal cells after oxidative stress. Intrinsic regenerative activity of neuron in reaction to external insults may be related to this increase in ApoE of neuronal origin.
载脂蛋白E（ApoE）在人脑中的细胞起源及其在生理和病理条件下的作用仍有待阐明。
对一系列有或无梗死的尸检人脑进行ApoE免疫定位研究。还通过免疫印迹法对尸检脑和人源培养神经母细胞瘤细胞系（GOTO）的蛋白质提取物中ApoE的表达进行了评估，该细胞系暴露于过氧化氢（0.2 mmol/L）诱导的氧化应激中。
除星形胶质细胞和小胶质细胞外，缺血灶内及周围的神经元和变性轴突含有ApoE样免疫反应性，在近期缺血灶中更为强烈。免疫印迹显示缺血性病变脑提取物中ApoE表达增加，应激后培养的神经母细胞瘤细胞系中这种增加也很明显。
人脑缺血灶内及周围神经元中ApoE的积累与神经元中ApoE合成增加有关，如氧化应激后培养的神经元细胞所见。神经元对外部损伤的内在再生活性可能与此起源于神经元的ApoE增加有关。
