|Budget Amount *help
¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 2002 : ¥1,200,000 (Direct Cost : ¥1,200,000)
The proportion of aged people in the whole population is increasing rapidly, so that maintaining skeletal muscle function is becoming more important for the healthy life of people. Recently, various kinds of methods for in vivo gene transfer have been developed. For maintaining muscle function, direct plasmid DNA injection into muscle might be useful for improvement of muscle function. Previously, I demonstrated that gene transfer into muscle by electroporation in vivo was far more efficient than simple intramuscular DNA injection. In this study, I speculated that this method might be used to allow rat muscle to express some genes related to muscle function, insulin-like growth factor 1 (IGF-1) for proliferation of muscle cells, vascular endothelial growth factor (VEGF) for angiogenesis, and growth hormone(GH). And some indices, concentration of DNA, DNA solution, structure of electrodes and frequency of pulse, were analyzed for improvement of efficiency of this method. Vectors inserted with CDNA of these genes were introduced into cultured cells, showing that products of these genes were secreted into the culture media. As a control study, a plasmid containing erythropoietin cDNA was introduced into rat muscle. The results showed that the best condition for gene transfer was as follows: injection of 400 μg of DNA and electroporation with 5mm-electrode needle, 8 times of 50 msec-pulse at 100V.
Intramuscular injection following by electroporation in vivo is simple and efficient for gene transfer, and may provide a potential approach toward systemic delivery of cytokines , growth factors, and other serum proteins for human gene therapy. More improvement of this method could contribute for human hearth.