Susceptibility to rotenone is increased in neurons from parkin null mice and is reduced by minocycline
Susceptibility to rotenone is increased in neurons from parkin null mice and is reduced by minocycline
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DOI：
10.1111/j.1471-4159.2006.03777.x
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发表时间：
2006-05-01
影响因子：
4.7
通讯作者：
Mena, MA
中科院分区：
文献类型：
--
作者：
Casarejos, MJ;Menéndez, J;Mena, MA
帕金森病是一种神经退行性疾病，在大多数情况下病因不明。Park-2基因的突变是家族性帕金森综合征的最常见原因，并且parkin敲除（PK-KO）小鼠具有类似于临床综合征的异常。我们研究了遗传和环境因素的相互作用，用鱼藤酮（ROT）处理来自PK-KO和野生型（WT）小鼠的中脑神经元培养物。ROT（0.025-0.1 μ M）产生剂量依赖性的酪氨酸羟化酶免疫反应细胞和其他神经元的选择性减少，如PK-KO培养物中微管相关蛋白2的免疫反应所示，表明ROT的毒性作用涉及多巴胺和其他类型的神经元。神经元的死亡主要是凋亡和抑制caspase抑制剂叔丁氧羰基-天冬氨酸（OMe）-氟甲基酮（Boc-D-FMK）。PK-KO培养物对低剂量ROT诱导的细胞凋亡比WT更敏感。ROT增加PK-KO中星形胶质细胞和小胶质细胞的比例多于WT培养物。环氧化酶抑制剂吲哚美辛可加重ROT对酪氨酸羟化酶细胞、细胞凋亡和星形胶质细胞（胶质细胞酸性蛋白）的作用。N-硝基-L-精氨酸甲酯，一氧化氮合酶抑制剂，增加ROT诱导的细胞凋亡，但不改变酪氨酸羟化酶免疫反应或胶质细胞酸性蛋白面积。吲哚美辛和N-硝基-L-精氨酸甲酯对ROT引起的线粒体电位降低均无任何影响，通过3-（4，5-二甲基噻唑-2-基）-2，5-二苯基四唑溴盐测定。小胶质细胞NADPH氧化酶抑制，但是，保护对ROT。分别用SB 20358和PD 98059处理，检测p38 MAPK和细胞外信号调节激酶信号通路的作用。这些化合物在ROT-幼稚培养物中是无活性的，但PD 98059轻微增加细胞坏死，如通过由ROT引起的乳酸脱氢酶水平所测量的，而不改变线粒体活性。SB 20358增加ROT诱导的线粒体功能衰竭和乳酸脱氢酶升高。米诺环素，小胶质细胞的抑制剂，防止脱落的酪氨酸羟化酶和细胞凋亡的ROT;此外，从PK-KO WT神经元培养的小胶质细胞增加多巴胺能神经元的敏感性ROT。PK-KO小鼠比WT对ROT更敏感，Park-2抑制和ROT的联合作用再现了在帕金森病中观察到的细胞事件。米诺环素预防了这些事件。
Parkinson's disease is a neurodegenerative disorder which is in most cases of unknown etiology. Mutations of the Park-2 gene are the most frequent cause of familial parkinsonism and parkin knockout (PK-KO) mice have abnormalities that resemble the clinical syndrome. We investigated the interaction of genetic and environmental factors, treating midbrain neuronal cultures from PK-KO and wild-type ( WT) mice with rotenone (ROT). ROT (0.025-0.1 mu(M)) produced a dosedependent selective reduction of tyrosine hydroxylase-immunoreactive cells and of other neurons, as shown by the immunoreactivity to microtubule-associated protein 2 in PK-KO cultures, suggesting that the toxic effect of ROT involved dopamine and other types of neurons. Neuronal death was mainly apoptotic and suppressible by the caspase inhibitor t-butoxycarbonyl-Asp(OMe)-fluoromethyl ketone (Boc-D-FMK). PK-KO cultures were more susceptible to apoptosis induced by low doses of ROT than those from WT. ROT increased the proportion of astroglia and microglia more in PK-KO than in WT cultures. Indomethacin, a cyclo-oxygenase inhibitor, worsened the effects of ROT on tyrosine hydroxylase cells, apoptosis and astroglial ( glial fibrillary acidic protein) cells. N-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthase, increased ROT-induced apoptosis but did not change tyrosine hydroxylase-immunoreactive or glial fibrillary acidic protein area. Neither indomethacin nor N-nitro-L-arginine methyl ester had any effect on the reduction by ROT of the mitochondrial potential as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. Microglial NADPH oxidase inhibition, however, protected against ROT. The roles of p38 MAPK and extracellular signal-regulated kinase signaling pathways were tested by treatment with SB20358 and PD98059, respectively. These compounds were inactive in ROT-naive cultures but PD98059 slightly increased cellular necrosis, as measured by lactate dehydrogenase levels, caused by ROT, without changing mitochondrial activity. SB20358 increased the mitochondrial failure and lactate dehydrogenase elevation induced by ROT. Minocycline, an inhibitor of microglia, prevented the dropout of tyrosine hydroxylase and apoptosis by ROT; the addition of microglia from PK-KO to WT neuronal cultures increased the sensitivity of dopaminergic neurons to ROT. PK-KO mice were more susceptible than WT to ROT and the combined effects of Park-2 suppression and ROT reproduced the cellular events observed in Parkinson's disease. These events were prevented by minocycline.