Development of Gene Therapy for Enhancing Neurogenesis after Cerebral Infarction

基因治疗可能显示出对中风患者的希望，但侵入性技术，如脑室内或脑内注射治疗基因可能具有有限的适用性。本研究的目的是开发系统性基因治疗，使用巨噬细胞浸润梗死递送和表达基因。在大鼠大脑中动脉（MCA）永久闭塞后，通过股静脉注射脂质体中的增强型绿色荧光蛋白（EGFP）质粒缀合物。我们还构建了成纤维细胞生长因子-2（FGF-2）和EGFP的双顺反子质粒载体，并将其用于MCA闭塞的其他大鼠。EGFP在正常脑组织中不表达，但在沿着梗死边缘聚集的巨噬细胞中表达强烈。在注射双顺反子FGF-2和EGFP质粒载体后，沿着梗死边缘的巨噬细胞中FGF-2蛋白的产生被诱导;与对照质粒载体相比，这刺激了缺血半球脑室下区神经祖细胞的增殖（61.7±5.2 vs 42.2±5.5个细胞/mm^2，各n=4，P<0.01）。总之，通过脂质体向浸润梗死灶的巨噬细胞进行系统性基因转移可能被证明对卒中的基因治疗有用。

Gene therapy may show promise for stroke patients, but invasive techniques such as intraventricular or intracerebral injection of therapeutic genes may have limited applicability. The purpose of this study is to develop systemic gene therapy, using macrophages infiltrating the infarct to deliver and express the gene. After permanent middle cerebral artery (MCA) occlusion in rats, an enhanced green fluorecescent protein (EGFP) plasmid conjugate in liposomes was injected via the femoral vein. We also constructed a bicistronic plasmid vector for fibroblast growth factor-2 (FGF-2) as well as EGFP, administering it in other rats with MCA occlusion. EGFP expression in normal brain was absent, but strong in macrophages accumulating along the infarct border. FGF-2 protein production was induced in macrophages along the infarct border after injection of bicistronic FGF-2 and EGFP plasmid vector ; this stimulated proliferation of neural progenitors in the subventricular zone in the ischemic hemisphere compared with control plasmid vectors (61.7±5.2 versus 42.2±5.5 cells per mm^2, n=4 each, P<0.01). In conclusion, systemic gene transfer by liposome to macrophages infiltrating an infarct may prove useful for gene therapy in stroke.