Reactive macrophages increase oxidative stress and alpha-synuclein nitration during death of dopaminergic neuronal cells in co-culture: Relevance to Parkinson's disease
Reactive macrophages increase oxidative stress and alpha-synuclein nitration during death of dopaminergic neuronal cells in co-culture: Relevance to Parkinson's disease
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DOI：
10.1007/s11064-005-9233-x
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发表时间：
2006-01-01
影响因子：
4.4
通讯作者：
Ebadi, M
中科院分区：
文献类型：
--
作者：
Shavali, S;Combs, C;Ebadi, M
帕金森氏病（PD）的特征在于多巴胺能神经元的进行性变性和脑的黑质-纹状体区域中的神经递质多巴胺的实质性减少。已在PD患者的脑中确定了氧化应激标志物增加、活化的小胶质细胞和促炎细胞因子水平升高。虽然PD神经元丢失的确切机制尚不清楚，但这些发现表明小胶质细胞活化可能直接导致PD患者多巴胺能神经元的丢失。在本研究中，我们测试的假设，激活的小胶质细胞诱导一氧化氮依赖的氧化应激，随后导致多巴胺能神经元细胞在培养中的死亡。我们采用脂多糖（LPS）刺激的小鼠巨噬细胞（RAW 264.7）作为反应性小胶质细胞模型和SH-SY 5 Y细胞作为人类多巴胺能神经元的模型。巨噬细胞的LPS刺激导致一氧化氮的产生以时间和剂量依赖性方式增加，以及随后产生其他活性氮物质，如过氧亚硝酸根阴离子。在共培养条件下，反应性巨噬细胞刺激SH-SY 5 Y细胞死亡，其特征在于SH-SY 5 Y细胞内过氧亚硝酸盐浓度增加和α-突触核蛋白硝化。重要的是，1400 W是一种诱导型一氧化氮合酶抑制剂，通过降低硝化的α-突触核蛋白水平来保护细胞免于死亡。这些结果表明，反应性小胶质细胞可以诱导多巴胺能神经元的氧化应激，这种氧化应激可能最终导致α-突触核蛋白的硝化和多巴胺能神经元的死亡。
Parkinson's disease ( PD) is characterized by progressive degeneration of dopaminergic neurons and a substantial decrease in the neurotransmitter dopamine in the nigro-striatal region of the brain. Increased markers of oxidative stress, activated microglias and elevated levels of pro-inflammatory cytokines have been identified in the brains of patients with PD. Although the precise mechanism of loss of neurons in PD remains unclear, these findings suggest that microglial activation may contribute directly to loss of dopaminergic neurons in PD patients. In the present study, we tested the hypothesis that activated microglia induces nitric oxide-dependent oxidative stress which subsequently causes death of dopaminergic neuronal cells in culture. We employed lipopolysaccharide ( LPS) stimulated mouse macrophage cells ( RAW 264.7) as a reactive microglial model and SH-SY5Y cells as a model for human dopaminergic neurons. LPS stimulation of macrophages led to increased production of nitric oxide in a time and dose dependent manner as well as subsequent generation of other reactive nitrogen species such as peroxynitrite anions. In co-culture conditions, reactive macrophages stimulated SH-SY5Y cell death characterized by increased peroxynitrite concentrations and nitration of alpha-synuclein within SH-SY5Y cells. Importantly 1400W, an inhibitor of the inducible nitric oxide synthase provided protection from cell death via decreasing the levels of nitrated alpha-synuclein. These results suggest that reactive microglias could induce oxidative stress in dopaminergic neurons and such oxidative stress may finally lead to nitration of alpha-synuclein and death of dopaminergic neurons in PD.