Ito Yoshihisa, Ito Moriyuki, Takagi Noritaka, Saito Hiroshi, Ishige Kumiko
Department of Pharmacology, College of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan.
Brain Res. 2003 Sep 19;985(1):98-107. doi: 10.1016/s0006-8993(03)03173-1.
We have assessed amyloid-beta (Abeta)-induced neurotoxicity, with and without added ibotenic acid (IBO), a potent N-methyl-D-aspartate (NMDA) agonist, in an organotypic hippocampal slice culture (OHC). In the OHC, there was little neurotoxicity after treatment with Abeta(25-35) (25 or 50 microM) alone for 48 h. However, with IBO alone neuronal death was observed in the pyramidal cell layer at low concentrations, and there was dramatic neuronal death at concentrations of 65 microM or more. When Abeta was combined with IBO (Abeta+IBO) there was more intense cell death than with IBO alone. S-Allyl-L-cysteine (SAC), one of the organosulfur compounds having a thioallyl group in aged garlic extract, was shown to protect the hippocampal neurons in the CA3 area and the dentate gyrus (DG) from the cell death induced by Abeta+IBO with no change in the CA1 area. Although L-glutamate (500 microM) potentiated the degree of IBO-induced neuronal death, it attenuated the Abeta+IBO-induced neuronal death in both the CA3 area and the DG with no obvious effect on the CA1 area. These results suggest that Abeta+IBO induces extensive neuronal death, and that SAC and L-glutamate protect cells from death in specific areas of the hippocampus. In addition, inhibition using a pan-caspase inhibitor, z-VAD-fmk, only provided partial protection from Abeta+IBO-induced toxicity for the neurons in the CA3 area. These results suggest that multiple mechanisms may be involved in Abeta+IBO-induced neuronal death in the OHC.
我们在器官型海马脑片培养物（OHC）中评估了β-淀粉样蛋白（Aβ）诱导的神经毒性，分别在添加和不添加强力N-甲基-D-天冬氨酸（NMDA）激动剂鹅膏蕈氨酸（IBO）的情况下进行。在OHC中，单独用Aβ（25-35）（25或50μM）处理48小时后几乎没有神经毒性。然而，单独使用IBO时，在低浓度下锥体细胞层就观察到神经元死亡，而在65μM或更高浓度时则出现显著的神经元死亡。当Aβ与IBO联合使用（Aβ+IBO）时，细胞死亡比单独使用IBO时更严重。S-烯丙基-L-半胱氨酸（SAC）是老化大蒜提取物中具有硫代烯丙基基团的有机硫化合物之一，它能保护CA3区和齿状回（DG）的海马神经元免受Aβ+IBO诱导的细胞死亡，而CA1区没有变化。虽然L-谷氨酸（500μM）增强了IBO诱导的神经元死亡程度，但它减弱了CA3区和DG中Aβ+IBO诱导的神经元死亡，对CA1区没有明显影响。这些结果表明，Aβ+IBO诱导广泛的神经元死亡，并且SAC和L-谷氨酸在海马的特定区域保护细胞免于死亡。此外，使用泛半胱天冬酶抑制剂z-VAD-fmk进行抑制，仅对CA3区的神经元提供了部分保护，使其免受Aβ+IBO诱导的毒性。这些结果表明，多种机制可能参与了OHC中Aβ+IBO诱导的神经元死亡。
