酪氨酸羟化酶cDNA移植治疗帕金森病的实验研究

Experimental research on transplantation of tyrosine hydroxylase cDNA in the treatment of Parkinson's disease

目的评价质粒ＤＮＡ脂质体复合物直接转染纹状体细胞表达酪氨酸羟化酶治疗帕金森病的疗效。方法应用６－羟多巴胺制备偏侧帕金森病大鼠模型，首次将表达大鼠酪氨酸羟化酶的质粒ＤＮＡ脂质体复合物植入大鼠损毁侧纹状体。移植后，观察大鼠模型旋转行为的改善程度，并用免疫组化及逆转录聚合酶链反应（ＲＴ－ＰＣＲ）检测酪氨酸羟化酶基因的表达。结果移植后２周鼠模型的旋转行为明显改善（治疗后３、６、９、１２及１５天旋转次数比治疗前分别减少４３．６％、３８．４％、３９．１％、４８．８％和５０．７％，Ｐ值均＜０．０１），且免疫组化及ＲＴ－ＰＣＲ也证实了外源性酪氨酸羟化酶互补ＤＮＡ（ｃＤＮＡ）可以进入脑细胞内，并表达出有生物活性的酪氨酸羟化酶。结论质粒ＤＮＡ脂质体复合物直接转染纹状体细胞能够表达出有生物活性的酪氨酸羟化酶，并能改善帕金森病鼠模型的行为症状，这一技术可望发展成为治疗帕金森病的有效方法。

Objective This study is intended to evaluate the effect of direct intracerebral genetransfer of a plasmid DNA-lipofectin complex expressing tyrosine hydroxylase (TH) on Parkinsonian rats. Methods A rat model of Parkinson's disease (PD) was induced by unilateral administration of 6-hydroxydopamine into right substantia nigra. Plasmid DNA-lipofectin complex expressing rat TH was delivered into the striatum of unilaterally denervated rats for the first time. After grafting, the rotation rate was measured as an index of behavior recovery, the expression of TH gene was detected by means of immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR).Results A partial reversal of rotational behaviour of rat model was obtained at two weeks after gene transfer (P<0.01) ,immunohistochemistry staining and RT-PCR also confirm that plasmid DNA-lipo-fectin complex directly injected into the striatum could be incorporated with neurons and it could express bioactivity in the striatum. Conclusions These results suggested that plasmid DNA-lipo-fectin complex containing the rat TH complementary DNA (cDNA) can express functional TH enzymatic activity and induce an efficient behavioral recovery of PD rat, and this technique is a potentially useful approach for treatment of PD.