Choi Hee Soon, Lee Sun Hwa, Kim So Young, An Jae Jin, Hwang Seok Il, Kim Dae Won, Yoo Ki Yeon, Won Moo Ho, Kang Tae Cheon, Kwon Hyung Joo, Kang Jung Hoon, Cho Sung Woo, Kwon Oh Shin, Choi Jin Hi, Park Jinseu, Eum Won Sik, Choi Soo Young
Department of Biomedical Sciences, Hallym University, Chunchon, Korea.
J Biochem Mol Biol. 2006 May 31;39(3):253-62. doi: 10.5483/bmbrep.2006.39.3.253.
Parkinson's disease (PD) is a common neurodegenerative disorder and is characterized by the progressive loss of dopaminergic neurons in the substantia nigra. Although many studies showed that the aggregation of alpha-synuclein might be involved in the pathogenesis of PD, its protective properties against oxidative stress remain to be elucidated. In this study, human wild type and mutant alpha-synuclein genes were fused with a gene fragment encoding the nine amino acid transactivator of transcription (Tat) protein transduction domain of HIV-1 in a bacterial expression vector to produce a genetic in-frame WT Tat-alpha-synuclein (wild type) and mutant Tat-alpha-synucleins (mutants; A30P and A53T), respectively, and we investigated the protective effects of wild type and mutant Tat-alpha-synucleins in vitro and in vivo. WT Tat-alpha-synuclein rapidly transduced into an astrocyte cells and protected the cells against paraquat induced cell death. However, mutant Tat-alpha-synucleins did not protect at all. In the mice models exposed to the herbicide paraquat, the WT Tat-alpha-synuclein completely protected against dopaminergic neuronal cell death, whereas mutants failed in protecting against oxidative stress. We found that these protective effects were characterized by increasing the expression level of heat shock protein 70 (HSP70) in the neuronal cells and this expression level was dependent on the concentration of transduced WT Tat-alpha-synuclein. These results suggest that transduced Tat-alpha-synuclein might protect cell death from oxidative stress by increasing the expression level of HSP70 in vitro and in vivo and this may be of potential therapeutic benefit in the pathogenesis of PD.
帕金森病（PD）是一种常见的神经退行性疾病，其特征是黑质中多巴胺能神经元逐渐丧失。尽管许多研究表明α-突触核蛋白的聚集可能参与了PD的发病机制，但其对氧化应激的保护特性仍有待阐明。在本研究中，将人类野生型和突变型α-突触核蛋白基因与编码HIV-1转录激活蛋白（Tat）蛋白转导结构域九个氨基酸的基因片段在细菌表达载体中融合，分别产生基因框架内的野生型Tat-α-突触核蛋白（野生型）和突变型Tat-α-突触核蛋白（突变体；A30P和A53T），并且我们在体外和体内研究了野生型和突变型Tat-α-突触核蛋白的保护作用。野生型Tat-α-突触核蛋白迅速转导至星形胶质细胞中，并保护细胞免受百草枯诱导的细胞死亡。然而，突变型Tat-α-突触核蛋白完全没有保护作用。在暴露于除草剂百草枯的小鼠模型中，野生型Tat-α-突触核蛋白完全保护多巴胺能神经元细胞免于死亡，而突变体未能抵御氧化应激。我们发现这些保护作用的特征是神经元细胞中热休克蛋白70（HSP70）的表达水平增加，并且该表达水平取决于转导的野生型Tat-α-突触核蛋白的浓度。这些结果表明，转导的Tat-α-突触核蛋白可能通过在体外和体内增加HSP70的表达水平来保护细胞免于氧化应激死亡，这可能对PD的发病机制具有潜在的治疗益处。
