Offen D, Sherki Y, Melamed E, Fridkin M, Brenneman D E, Gozes I
Department of Clinical Biochemistry and Felsentein Medical Research Center, Rabin Medical Center, The Sackler Faculty of Medicine, Tel Aviv University, Israel.
Brain Res. 2000 Jan 31;854(1-2):257-62. doi: 10.1016/s0006-8993(99)02375-6.
Vasoactive intestinal peptide (VIP) provides neuroprotection against beta-amyloid toxicity in models of Alzheimer's disease. A superactive analogue, stearyl-Nle17-VIP (SNV) is a 100-fold more potent than VIP. In primary neuronal cultures, VIP protective activity may be mediated by femtomolar-acting glial proteins such as activity-dependent neurotrophic factor (ADNF), activity-dependent neuroprotective protein (ADNP), peptide derivatives ADNF-9 (9aa) and NAP (8aa), respectively. It has been hypothesized that beta-amyloid induces oxidative stress leading to neuronal cell death. Similarly, dopamine and its oxidation products were suggested to trigger dopaminergic nigral cell death in Parkinson's disease. We now examined the possible protective effects of VIP against toxicity of dopamine, 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenylpyridinium ion (MPP+) in neuronal cultures [rat pheochromocytoma (PC12), human neuroblastoma (SH-SY5Y) and rat cerebellar granular cells]. Remarkably low concentrations of VIP (10(-16)-10(-8) M), ADNF-9 and NAP (10(-18)-10(-10) M) protected against dopamine and 6-OHDA toxicity in PC12 and neuroblastoma cells. VIP (10(-11)-10(-9) M) and SNV (10(-13)-10(-11) M), protected cerebellar granule neurons against 6-OHDA. In contrast, VIP did not rescue neurons from death associated with MPP+. Since dopamine toxicity is linked to the red/ ox state of the cellular glutathione, we investigated neuroprotection in cells depleted of reduced glutathione (GSH). Buthionine sulfoximine (BSO), a selective inhibitor of glutathione synthesis, caused a marked reduction in GSH in neuroblastoma cells and their viability decreased by 70-90%. VIP, SNV or NAP (over a wide concentration range) provided significant neuroprotection against BSO toxicity. These results show that the mechanism of neuroprotection by VIP/SNV/NAP may be mediated through raising cellular resistance against oxidative stress. Our data suggest these compounds as potential lead compounds for protective therapies against Parkinson's disease.
血管活性肠肽（VIP）在阿尔茨海默病模型中对β-淀粉样蛋白毒性具有神经保护作用。一种超活性类似物，硬脂酰 - Nle17 - VIP（SNV）的效力比VIP强100倍。在原代神经元培养中，VIP的保护活性可能由飞摩尔作用的神经胶质蛋白介导，如活性依赖性神经营养因子（ADNF）、活性依赖性神经保护蛋白（ADNP）、肽衍生物ADNF - 9（9aa）和NAP（8aa）。据推测，β-淀粉样蛋白诱导氧化应激导致神经元细胞死亡。同样，多巴胺及其氧化产物被认为在帕金森病中触发多巴胺能黑质细胞死亡。我们现在研究了VIP对神经元培养物[大鼠嗜铬细胞瘤（PC12）、人神经母细胞瘤（SH - SY5Y）和大鼠小脑颗粒细胞]中多巴胺、6 - 羟基多巴胺（6 - OHDA）和1 - 甲基 - 4 - 苯基吡啶离子（MPP⁺）毒性的可能保护作用。极低浓度的VIP（10⁻¹⁶ - 10⁻⁸ M）、ADNF - 9和NAP（10⁻¹⁸ - 10⁻¹⁰ M）可保护PC12和神经母细胞瘤细胞免受多巴胺和6 - OHDA毒性。VIP（10⁻¹¹ - 10⁻⁹ M）和SNV（10⁻¹³ - 10⁻¹¹ M）可保护小脑颗粒神经元免受6 - OHDA毒性。相比之下，VIP不能挽救与MPP⁺相关死亡的神经元。由于多巴胺毒性与细胞谷胱甘肽的氧化还原状态有关，我们研究了在还原型谷胱甘肽（GSH）耗尽的细胞中的神经保护作用。丁硫氨酸亚砜胺（BSO）是谷胱甘肽合成的选择性抑制剂，可导致神经母细胞瘤细胞中GSH显著降低，其活力降低70 - 90%。VIP、SNV或NAP（在广泛的浓度范围内）对BSO毒性提供了显著的神经保护作用。这些结果表明，VIP / SNV / NAP的神经保护机制可能是通过提高细胞对氧化应激的抵抗力来介导的。我们的数据表明这些化合物是帕金森病保护性治疗的潜在先导化合物。
