Neuroprotective mechanism of apolipoprotein E

载脂蛋白E的神经保护机制

• 批准号: 14599008
• 负责人: MITSUDA Noriaki
• 金额: $ 2.18万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14599008/
• 关键词: Apolipoprotein E; reelin; neuroprotection; Tau; リン酸化; GSK-3β

Specific Aim : In the brain, apolipoprotein E(ApoE) is secreted from astrocytes and microglias, and plays important roles in lipid transportation. Furthermore, ApoE may protect neurons from many kinds of insults. Our aim is to elucidate the molecular mechanisms where ApoE protect neurons.Results : When primary neurons were cultured under serum-free conditions, they underwent cell deaths. When ApoE3 was added to the serum-free medium, their deaths were significantly inhibited, On the other hand, when ApoE4 was added to the serum-free medium, their deaths were significantly promoted. Tau protein in the neurons were significantly phosphorylated, then. To substantiate this concept, we mated Reelin-deficient mice to ApoE-deficient mice and found that in the absence of Reelin, tau-phosphorylation in neurons of the brain increased as the amount of ApoE decreased. Paralleling the change in tau-phosphorylation levels, we found that GSK-3β activity increased in Reelin-deficient mice and further increased in mice lacking both Reelin and ApoE. CDK-5 activity was similar in mice lacking Reelin, ApoE, or both. GSK-3β and CDK-5 activity increased in Dab1-deficient mice, independent of ApoE levels. Further supporting the idea that increased tau-phosphorylation results primarily from increased kinase activity, the activity of 2 phosphatases were similar in all conditions tested.Conclusions : These data support a novel, ligand-mediated signal transduction cascade-initiated by the assembly of a RAD complex that suppresses kinase activity and controls tau-phosphorylation.

具体目的 : 在大脑中，载脂蛋白 E (ApoE) 由星形胶质细胞和小胶质细胞分泌，在脂质运输中发挥重要作用。此外，ApoE 可以保护神经元免受多种损伤。我们的目的是阐明ApoE保护神经元的分子机制。结果：当原代神经元在无血清条件下培养时，它们发生细胞死亡。当无血清培养基中添加ApoE3时，其死亡受到显着抑制；而当无血清培养基中添加ApoE4时，其死亡则显着促进。然后神经元中的 Tau 蛋白被显着磷酸化。为了证实这一概念，我们将 Reelin 缺陷小鼠与 ApoE 缺陷小鼠交配，发现在 Reelin 缺失的情况下，大脑神经元中的 tau 磷酸化随着 ApoE 数量的减少而增加。与 tau 磷酸化水平的变化平行，我们发现 Reelin 缺陷小鼠中 GSK-3β 活性增加，并且 Reelin 和 ApoE 缺乏的小鼠中 GSK-3β 活性进一步增加。在缺乏 Reelin、ApoE 或两者的小鼠中，CDK-5 活性相似。 Dab1 缺陷小鼠中 GSK-3β 和 CDK-5 活性增加，与 ApoE 水平无关。两种磷酸酶的活性在所有测试条件下都相似，进一步支持了 tau 磷酸化增加主要由激酶活性增加导致的观点。结论：这些数据支持一种新型的配体介导的信号转导级联，由抑制激酶活性并控制 tau 磷酸化的 RAD 复合物组装引发。

项目成果

Mori K, Yokoyama A, Yang L, Yang L, Maeda N, Mitsuda N, Tanaka J: "L-Serine-mediated release of apolipoprotein E and lipids from microglial cells."Experimental Neurology. 185・2. 220-231 (2004)

Mori K、Yokoyama A、Yang L、Yang L、Maeda N、Mitsuda N、Tanaka J：“L-丝氨酸介导的小胶质细胞中载脂蛋白 E 和脂质的释放”。实验神经病学 185・2。 ）

Kohji Mori et al.: "L-Serine-mediated release of apolipoprotein E and lipids from microglial cells."Experimental Neurology. 185. 220-231 (2004)

Kohji Mori 等人：“L-丝氨酸介导的小胶质细胞中载脂蛋白 E 和脂质的释放。”实验神经病学。

Atsuyuki Morishima et al.: "KFκB regulates plasma apolipoprotein A-I and HDL-cholesterol through inhibition of PPARα"Journal of Biological Chemistry. 278. 38188-38193 (2003)

Atsuyuki Morishima 等人：“KFκB 通过抑制 PPARα 调节血浆载脂蛋白 A-I 和 HDL-胆固醇”《生物化学杂志》278. 38188-38193 (2003)。

Ohkubo N, Lee YD, Morishima A, Terashima T, Kikkawa S, Tohyama M, Sakanaka M, Tanaka J, Maeda N, Vitek MP, Mitsuda N: "Apolipoprotein E and Reelin ligands modulate tau phosphorylation through an apolipoprotein E receptor/disabled-1/glycogen synthase kinas

Ohkubo N、Lee YD、Morishima A、Terashima T、Kikkawa S、Tohyama M、Sakanaka M、Tanaka J、Maeda N、Vitek MP、Mitsuda N：“载脂蛋白 E 和 Reelin 配体通过载脂蛋白 E 受体/禁用-调节 tau 磷酸化

Nobutaka Ohkubo et al.: "Apolipoprotein E and Reelin ligands modulate tau phosphorylation through an apolipoprotein E receptor/disabled-1/glycogen synthase kinase-3beta cascade."FASEB Journal. 17. 295-297 (2003)

Nobutaka Ohkubo 等人：“载脂蛋白 E 和 Reelin 配体通过载脂蛋白 E 受体/disabled-1/糖原合酶激酶-3beta 级联调节 tau 磷酸化。”FASEB 杂志。