基因治疗巴金森氏病大鼠模型的实验研究

AN EXPERIMENTAL STUDY ON RAT MODEL OF PARKINSONIZM BY GENE THERAPY

巴金森氏病以黑质多巴胺能神经元变性减少为特征，以６－羟多巴胺单侧损毁大鼠脑内多巴胺能系统可建立巴金森氏病的动物模型，当给予阿普吗啡后通过检测这些大鼠的旋转圈数和纹状体多巴胺及其主要代谢产物的水平则可反映多巴胺的减少或恢复程度。为达到基因治疗巴金森氏病大鼠模型的目的，本研究将带有酪氨酸羟化酶基因的重组载体－质粒ｐＣＭＶＴＨ（６．０４ｋｂ）在体外通过脂质体转染技术转入原代培养的骨骼肌细胞内；再将这些经遗传改造、能表达酪氨酸羟化酶的骨骼肌细胞植入模型大鼠脑的纹状体内。结果显示，这些表达酪氨酸羟化酶的肌细胞可在大鼠模型脑内长期存活，这些模型大鼠的异常运动显现实质性改善，它们的纹状体多巴胺水平明显升高。

Parkinson's disease(PD)is characterized by a loss of the dopaminergic neurons of the substantia nigra.The rat with a unilatecal 6-OHDA-induced lesion of the dopaminergic system provided an animal model for PD. The quantifiable rotation of those rats after apomorphine administration and their striatal levels of dopamine(DA)and its major metabolities were used for exploring the degree of DA loss or replacement.The present study was intracerebral grafting(ICG)of the genetically modified cells which could express tyrosine hydroxylase(TH),in order to induce significant improvement of motor abnormalities and striatal DA levels in rat model.The cultuted primary muscle cells were selected for genetic modification and ICG.The recombinant vectors, pCMVTH(6.04 kb)containing TH gene, were transferred into the myoblasts and myotubes in vitro by using lipofection technique.The genetically altered cells expressing TH in vitro were then grafted into the striatum. The results showed those TH-expressing muscle cells had a long-term survival in vivo and induced a marked decrease in abnormal locomotion and increase in striatal DA levels for rat model.