ABSTRACT
The number of dysrophin-positive fibers appearing in the femoral quadriceps muscle of mdx mice after injection of the full-length human dystrophin cDNA within the pHSADy plasmid was examined by means of immunohystochemical techniques. Transfection was carried out using lipofectamine (LFA), or synthetic oligopeptide complexes that provided the condensation of plasmid DNA (K8) and its release from endosomes gopeptide complexes that provided the condensation of plasmid DNA (K8) and its release from endosomes (JTS1). The LFA + pHSADy at a dose of 10 micrograms DNA did not affect the number of dystrophin-positive fibers at the site of injection (0.6-0.8%), whereas it caused a statistically significant increase in the number of these fibers in the same muscle of the contralateral leg (up to 2.3%). Injection of the SO + pHSADy complex resulted in the occurrence of dystrophin-positive muscle fibers characterized by a heterogeneous content and the distribution of dystrophin. The greatest number of dystrophin-positive fibers (about 16%) was observed under a ratio of pHSADy to K8 of 1:3 or 1:4. The observed maximal number of dystrophin-positive fibers after a single injection of SO + pHSADy was 3.8%, and it was 17.7% after three injections. These values were statistically significantly higher compared to intact mice (0.6%), the injection of pure plasmid (2.2%), or the intramuscular injection of sucrose (from 0.7 to 1.3%). A relatively high level of transfection (about 5%) was observed after an intracardiac injection of a large dose of the pHSADy (70 micrograms DNA). The perspectives of the targeted delivery of the dystrophin gene into muscles under conditions of parenteral administration are discussed.
Subject(s)
Dystrophin/genetics , Gene Expression Regulation/physiology , Muscle Fibers, Skeletal/metabolism , Transfection , Amino Acid Sequence , Animals , Cation Exchange Resins/administration & dosage , Drug Carriers , Genetic Therapy , Genetic Vectors , Humans , Lipids/administration & dosage , Liposomes , Male , Mice , Mice, Inbred mdx , Molecular Sequence Data , Muscular Dystrophy, Animal/therapy , Oligopeptides/administration & dosageABSTRACT
"Gene-gun" ballistic transfection (BT) was used to deliver genetic constructs pMLVDy and pHSADy containing full-length cDNA of the dystrophin gene to musculus quadriceps remoris and musculus gluteus of mdx mice, which represent a natural model of Duchenne muscular dystrophy. Clusters of dystrophin-positive muscular fibers (DPMF) were immunocytochemically detected in sites exposed to BT. The average number of DPMF was 2% by the 17th day and 3% by the 60th day after BT with pMLVDy, whereas the number of revertant DPMF was 0.2% in control mice (without BT). When pHSADy was used, the average number of DPMF was 3% 20 days after BT. In this case, dystrophin was uniformly spread though the myoplasm in 3% of cells and produced a slight signal in separate regions under the sarcolemma in 10% of muscle fibers. The number of revertant DPMF increased to 0.6% after BT with naked particles and to 2.8% after BT with the marker lacZ gene, in both bombarded and contralateral legs. The number of DPMF in the corresponding muscles of the contralateral leg significantly increased and reached 2.8% by the 60th day after BT with pMLVDy and 6.7% by the 20th day after BT with pHSADy. Human dystrophin gene cDNA was detected in all skeletal muscles, heart, intestine, tongue, and brain by polymerase chain reaction (PCR) three weeks after BT. Immunoblot analysis showed that normal 427-kDa human dystrophin was synthesized in muscles of mdx mice. The results suggest applicability of BT for delivery of dystrophin constructs into muscles.
