Tetrahydrobiopterin precursor sepiapterin provides protection against neurotoxicity of 1-methyl-4-phenylpyridinium in nigral slice cultures
Tetrahydrobiopterin precursor sepiapterin provides protection against neurotoxicity of 1-methyl-4-phenylpyridinium in nigral slice cultures
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DOI：
10.1046/j.1471-4159.2003.01666.x
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发表时间：
2003-04-01
影响因子：
4.7
通讯作者：
Gramsbergen, JB
中科院分区：
文献类型：
--
作者：
Madsen, JT;Jansen, P;Gramsbergen, JB
复合物-I抑制和氧化过程与帕金森病中黑质多巴胺神经元的损失以及MPTP及其代谢物MPP+的毒性有关。四氢生物蝶呤是酪氨酸羟化酶的一种重要辅因子，可能在多巴胺能神经元中起抗氧化剂的作用，并防止谷胱甘肽耗竭的毒性后果。在这里，我们研究了操纵四氢生物蝶呤水平MPP+毒性器官型，大鼠腹侧中脑切片文化的影响。在培养中暴露于30 μ M MPP +2天，然后在对照培养基中"恢复" 8天，我们通过HPLC测定组织和培养基中的多巴胺及其代谢产物，乳酸脱氢酶释放到培养基中，碘化丙啶的细胞摄取，并计数酪氨酸羟化酶免疫反应神经元。2，4-二氨基-6-羟基嘧啶抑制四氢生物蝶呤合成对MPP+毒性无明显协同作用。相比之下，四氢生物蝶呤前体L-sepiapterin以剂量依赖性方式减弱MPP+诱导的多巴胺消耗和酪氨酸羟化酶阳性细胞的损失，40 μ M L-sepiapterin提供最大保护。因此，增加细胞内四氢生物蝶呤水平可以通过复合物-I抑制来保护免受氧化应激。
Complex-I inhibition and oxidative processes have been implicated in the loss of nigral dopamine neurones in Parkinson's disease and the toxicity of MPTP and its metabolite MPP+. Tetrahydrobiopterin, an essential cofactor for tyrosine hydroxylase, may act as an antioxidant in dopaminergic neurones and protects against the toxic consequences of glutathione depletion. Here we studied the effects of manipulating tetrahydrobiopterin levels on MPP+ toxicity in organotypic, rat ventral mesencephalic slice cultures. In cultures exposed to 30 muM MPP+ for 2 days, followed by 8 days 'recovery' in control medium, we measured dopamine and its metabolites in the tissue and culture medium by HPLC, lactate dehydrogenase release to the culture medium, cellular uptake of propidium iodide and counted the tyrosine hydroxylase-immunoreactive neurones. Inhibition of tetrahydrobiopterin synthesis by 2,4-diamino-6-hydroxypyrimidine had no significant synergistic effect on MPP+ toxicity. In contrast, the tetrahydrobiopterin precursor L-sepiapterin attenuated the MPP+-induced dopamine depletion and loss of tyrosine hydroxylase-positive cells in a dose-dependent manner with 40 muM L-sepiapterin providing maximal protection. Accordingly, increasing intracellular tetrahydrobiopterin levels may protect against oxidative stress by complex-I inhibition.