Shen Y, Muramatsu S I, Ikeguchi K, Fujimoto K I, Fan D S, Ogawa M, Mizukami H, Urabe M, Kume A, Nagatsu I, Urano F, Suzuki T, Ichinose H, Nagatsu T, Monahan J, Nakano I, Ozawa K
Division of Genetic Therapeutics, Center for Molecular Medicine, Jichi Medical School, Tochigi, Japan.
Hum Gene Ther. 2000 Jul 20;11(11):1509-19. doi: 10.1089/10430340050083243.
Parkinson's disease (PD), a neurological disease suited to gene therapy, is biochemically characterized by a severe decrease in the dopamine content of the striatum. One current strategy for gene therapy of PD involves local production of dopamine in the striatum achieved by inducing the expression of enzymes involved in the biosynthetic pathway for dopamine. We previously showed that the coexpression of tyrosine hydroxylase (TH) and aromatic-L-amino-acid decarboxylase (AADC), using two separate adeno-associated virus (AAV) vectors, resulted in more effective dopamine production and more remarkable behavioral recovery in 6-hydroxydopamine-lesioned parkinsonian rats, compared with the expression of TH alone. Not only levels of TH and AADC but also levels of tetrahydrobiopterin (BH4), a cofactor of TH, and GTP cyclohydrolase I (GCH), a rate-limiting enzymes for BH4 biosynthesis, are reduced in parkinsonian striatum. In the present study, we investigated whether transduction with separate AAV vectors expressing TH, AADC, and GCH was effective for gene therapy of PD. In vitro experiments showed that triple transduction with AAV-TH, AAV-AADC, and AAV-GCH resulted in greater dopamine production than double transduction with AAV-TH and AAV-AADC in 293 cells. Furthermore, triple transduction enhanced BH4 and dopamine production in denervated striatum of parkinsonian rats and improved the rotational behavior of the rats more efficiently than did double transduction. Behavioral recovery persisted for at least 12 months after stereotaxic intrastriatal injection. These results suggest that GCH, in addition to TH and AADC, is important for effective gene therapy of PD.
帕金森病（PD）是一种适合基因治疗的神经疾病，其生化特征是纹状体中多巴胺含量严重降低。目前一种帕金森病基因治疗策略是通过诱导多巴胺生物合成途径中相关酶的表达，在纹状体中局部产生多巴胺。我们之前表明，使用两种单独的腺相关病毒（AAV）载体共表达酪氨酸羟化酶（TH）和芳香族L-氨基酸脱羧酶（AADC），与单独表达TH相比，在6-羟基多巴胺损伤的帕金森病大鼠中能产生更有效的多巴胺，并带来更显著的行为恢复。帕金森病纹状体中不仅TH和AADC的水平降低，TH的辅因子四氢生物蝶呤（BH4）以及BH4生物合成的限速酶GTP环化水解酶I（GCH）的水平也降低。在本研究中，我们调查了用表达TH、AADC和GCH的单独AAV载体进行转导对帕金森病基因治疗是否有效。体外实验表明，在293细胞中，用AAV-TH、AAV-AADC和AAV-GCH进行三联转导比用AAV-TH和AAV-AADC进行双转导产生更多的多巴胺。此外，三联转导增强了帕金森病大鼠去神经支配纹状体中BH4和多巴胺的产生，并比双转导更有效地改善了大鼠的旋转行为。立体定向纹状体内注射后，行为恢复持续至少12个月。这些结果表明，除了TH和AADC外，GCH对帕金森病的有效基因治疗也很重要。
