Gene delivery of naked plasmid dna by retrograde coronary vein perfusion

Abstract

Purpose: Gene delivery into a heart by injection through the NOGA needle catheter or direct injection via a thoracotomy incision is being performed but these methods have the disadvantage of being invasive, and there is a risk of complications.We evaluated the efficiency and safety of hydrodynamics gene delivery of naked plasmid DNA by retrograde coronary vein perfusion. Method: Venous access of a miniature pig was obtained via the jugular vein.A 6 Fr occlusion ballon catheter was advanced into the anterior interventricular vein.30 ml saline with 3 mg of plasmid encoding Lac Z gene(pCAGGS-LacZ) was infused within about 20 seconds. After 7 days, mRNA of LacZ, bFGF,VEGF and IGF in myocardial tissues from twelve regions were measured by quantitative RT-PCR and positive cells staining to beta-galactosidase were analyzed by histochemistry. Result: LacZ gene was expressed in the proximal and distal regions near LAD and 1-3% of cardiomyocytes were stained by beta-galactosidase.The gene expression of LacZ in the distal region near LAD was about ten times stronger than that of endogenous IGF or bFGF and was similar to that of endogenous VEGF. Infusion of plasmid induced ST depression in ECG,but risky arrhythmia didn't occur.Pathological findings showed no myocardial damage. Conclusion: Hydrodynamics gene delivery of naked plasmid DNA by retrograde coronary vein perfusion was effective.Moreover, it is a simple and safe method of gene delivery.