外源性TH基因在帕金森氏病鼠脑内的表达──行为和TH免疫组化的研究

EXPRESSION OF FOREIGN TYROSINE HYDROXYLASE GENE IN THE RAT MODEL OF PARKINSONI'S DISEASE

用成年大鼠75只，给右侧黑质区注射6-羟基多巴胺（6－OHDA），损毁黑质多巴胶能神经元，制备偏侧帕金森氏病（PD）鼠模型。四周后，注射阿朴吗啡（APO）诱发大鼠向左侧旋转。旋转数为每分钟7次以上的35只PD鼠作实验用。其中实验组15只，对照组20只。向实验组PD鼠右侧纹状体多点植入含大鼠酪氨酸羟化酶cDNA（THcDNA）的真核表达载体pSVK3－TH和脂质体Lipofectin混合的基因转染复合体。对照组分2组，每组10只。一组PD鼠右侧纹状体只植入pSVK3－TH，另一组仅植入Lipofectin。所有实验动物在移植后的18d内，每隔3d注射APO诱发旋转。并与移植前作比较。结果是：实验组的PD鼠，在移植后的12d内旋转数比移植前明显减少，到第15天后，旋转数接近移植前水平。经TH免疫组织化学检查，在移植后6d和12d的，右侧纹状体内有TH免疫阳性细胞。主要位于移植周围。移植后18d的，未发现TH免疫阳性细胞。对照组的所有PD鼠，除其不对称旋转数与移植前比无变化外，在右侧纹状体内，也无TH阳性细胞。本研究首先证明了脂质体可介导TH基因进入PD鼠纹状体内的细胞并获得成功的表达，表达时程与功能变化时程相一致。该结果可能会为PD病人基因治疗的临床应用提供新的参考资料。

A total of 75 adult rats were used to produce hemiparkinson's disease (PD) model by unilateral injection of 6-hydroxydopamine (6-OHDA) into the right substuntial nigra. Four weeks following the lesions, rats were tested for apomorphine (APO) -induced asymmetric rotation. Only rats that showed more than seven turns per minute were selected as PD models for transplantation. A tyrosine hydroxylase expression plasmid (pSVK3-TH) mixed with lipofectin was transplanted into the right striatum of 15PD rats. Another 20 PD rats transplanted either with lipofectin or with pSVK3-TH served as controls. Every three days following transplantation, the performance of asymmetric rotation were tested and stained with the TH-immunohistochemistry. Only the animals grafted with pSVK3-TH mixed with lipofectin were found to show the decreased rotutional behavior and a few TH-positive cells in the right striatum at the postgraft day 3~12, but not day 18. The results indicate that there exists a correlation between amelioration of asymmetric rotation and the TH gene expression in the denervated striatum. It is suggested that the lipofectin may mediatc foreign TH gene expression in the PD rat brain.