High-efficiency growth hormone-releasing hormone plasmid vector administration into skeletal muscle mediated by electroporation in pigs.
We report here a very efficient method for the in vivo transfer of therapeutic plasmid DNA into porcine muscle fibers by using electric pulses of low field intensity. We evaluated delivery of 0.1-3 mg of plasmid vectors that encode reporter secreted-embryonic alkaline phosphatase (SEAP) or therapeutic growth hormone releasing hormone (GHRH). Reporter gene studies showed that internal needle electrodes give a 25-fold increase in expression levels compared with caliper electrodes in skeletal muscle in swine. Dose and time courses were performed. Pigs injected with 0.1 mg plasmid had significantly greater weight gain than controls over 53 days (22.4 +/- 0.8 kg vs. 19.7 +/- 0.03 kg, respectively; P<0.01). The group treated with GHRH-expressing plasmid at 14 days of age demonstrated greater weight gain than controls at every time point (25.8 +/- 1.5 kg vs. 19.7 +/- 0.03 kg; P<0.01). Body composition studies by dual X-ray absorbitometry showed a 22% decrease in fat deposition (P<0.05) and a 10% increase in bone mineral density (P<0.004). Our studies demonstrate that by optimizing the electroporation method, favorable physiological changes, such as enhanced weight gain and improved body composition, can be obtained at extremely low plasmid doses in a large mammal.
Draghia-Akli
Ruxandra
R
Department of Molecular and Cellular Biology, Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas, USA. ruxandradraghia@advisys.net
Ellis
Kenneth M
KM
Hill
Leigh-Anne
LA
Malone
P Brandon
PB
Fiorotto
Marta L
ML
D000818:Animals; D001823:Body Composition; D018274:Electroporation / Q000379:methods*; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D013007:Growth Hormone-Releasing Hormone / Q000235:genetics*; D007700:Kinetics; D018482:Muscle, Skeletal; D010957:Plasmids; D011506:Proteins / Q000235:genetics; D013552:Swine; D015430:Weight Gain
D011506:Proteins; D013007:Growth Hormone-Releasing Hormone