帕金森病基因治疗的实验研究

帕金森病(PD)的主要病理特征是中脑黑质多巴胺能神经元变性,表达的酪氨酸羟化酶(TH)减少或者活性降低。目前外源性多巴是最有效的抗PD药物,但常在数年后失去其有效的治疗作用。用胚胎脑细胞移植虽有效果,但胚胎脑来源困难。因此需要探索新的有效治疗方法。本研究将遗传修饰的成肌细胞植入偏侧PD鼠模型纹状体进行基因治疗。移植转TH基因的成肌细胞(治疗组,n=24)和未经遗传修饰的成肌细胞(对照组,n=10)于偏侧PD鼠损毁侧纹状体。用阿朴吗啡(APO)诱发旋转行为,RT-PCR、TH免疫组化检测TH基因的表达和TH蛋白的合成以及HPLC-ECD检测纹状体多巴胺及代谢产物含量以此评估基因治疗的效果。治疗组移植治疗后APO诱发的旋转行为明显改善(P<0.01),且可持续13个月,而对照组APO诱发的旋转行为无改善(P>0.05),应用RT-PCR、TH免疫组化和HPLC-ECD在治疗组移植部位检测到TH基因的表达、TH蛋白的合成和移植侧纹状体部多巴胺及其代谢产物含量增高。遗传修饰的成肌细胞能够在体内长时间、有效地表达TH,并改善PD鼠的病理行为,是PD基因治疗的合适靶细胞之一。

Experimental Research on Gene Therapy of Parkinson's Disease

Parkinson's disease (PD) is characterized principally by a progressive degeneration of nigral dopaminergic neurons and reduction of gene express of tyrosine hydroxylase (TH). In this study, the use of molecular biological techniques, genetically modified myoblast for trans plantation were investigated. Myoblast infected with TH (experimental group, n = 24) and uninfected myoblast (control group, n = 10) were grafted separately into the lesioned striatum of rats with unilateral 6-OHDA lesions of nigrostriatal pathway, only the animal received the transplantation of genetically modified myoblast expressing TH displayed a partial reversal of APO-induced turning behavior (P<0. 01)). Behavioral recovery was maintained for 13 months after grafting. The animals received the transplantation of unmodified myoblast without TH did not show the improvement. The elevation of TH activity and dopamine content were noted in the lesioned striatum. And the expression of TH mRNA and its immunoactivity were detected. This consistent ability of the genetically modified myoblast to promote high level of intracerebral transgene expression and substantially to reduced rotational behavior in the rat PD model make it an attractive candidate for gene therapy.