Research of dystrophin expression regulatory region and physiological function, and gene therapy for DMD.

在过去的10年里，我们一直在努力了解dystrophin(Dy)的生理功能，以开发有效的临床和基因治疗。我们认为，研究dy的表达调控区域是了解dy的生理功能的合理途径。基于这一观点，我们利用转基因小鼠分析了肌型dy启动子区域。我们报道了一段0.9kb的小鼠dy肌肉启动子片段，该片段包含仅在右心表达dy所需的调控元件。在这项研究中，为了进一步表征肌肉类型启动子的调控，我们在体外和体内使用了围绕人dy肌肉特异性外显子1的总共14kb的片段来分析启动子的活性和组织特异性。Lu体外分析表明，7kb启动子和7kb内含子1的LacZ结构在C2/4肌管中的表达强度是只有7kb启动子的LacZ结构的2.5倍。活体分析显示，这两个结构在整个心脏、骨骼肌和胚胎中的血管平滑肌中都有表达。然而，在成年人中，骨骼肌中的表达消失了。结果表明，7kb的上游区和7kb的内含子区域包括在心脏中表达的负责元件，而在活体的骨骼肌中不表达。在今后的研究中，我们必须考虑和关注血管系统中血管平滑肌的动态定位，为临床和基因治疗指明正确的方向。

We have been trying to know the physiological function of dystrophin (dy) to develop effective clinical and gene therapy, during last 10 years. We considered that investigation of regulatory region of dy expression is reasonable way to know the physiological function of dy. Because of this view point we analyzed muscle type dy promoter region, using trausgenic mice. We reported a 0.9kb fragment from a mouse dy muscle promoter that contains the regulatory elements required for expression of dy only in the right heart. In this study, to further characterize the regulation of muscle type promoter, we analyzed promoter activity and tissue specificity using a total 14kb fragment around the human dy muscular-specific exon 1 in vitro and in vivo. Lu vitro analysis showed that the lacZ construct of the 7kb promoter and 7kb intron 1 was expressed 2.5 times as strongly as the lacZ construct of only the 7kb promoter in C2/4 myotubes. In vivo analysis revealed expression of both constructs in the whole heart, skeletal muscle and vascular smooth muscle in embryos. However, in adults, the expression in skeletal muscle disappeared. The results showed that the 7kb upstream region and the 7kb intronic region included responsible elements for the expression in the heart, but not in skeletal muscle in vivo. In future investigation we have to consider and pay attention to the dy localization on the smooth muscle of the vascular system, to show correct way to go for the clinical and gene therapy.