Nucleic acid-based therapies using living myocardial slices

Abstract Background Gene therapy based on viral vectors is a promising new approach and offers great potential for the study treatment of cardiac diseases. Nucleic acid-based transfection human heart tissue could be considered valid translational alternative to use transgenic animal models in cardiovascular research. Purpose Here we explore Living Myocardial Slices (LMS) as platform nucleic therapies. Rat LMS Adeno-Associated viruses (AAV) were used optimise analyse gene transfer efficiency, viability, functionality, cell tropism tissue. Human samples from failing (dilated cardiomyopathy) hearts also validate model. In addition, transfected tested first time regenerative effect AAV-miR-199a both healthy pathologically overloaded LMS. Methods (300 μm thick) prepared glued PTFE-coated holders, mounted custom stretchers, cultured at physiological sarcomere length 72-hours under electrical stimulation. Two recombinant AAV serotypes (AAV-6 AAV-9) different multiplicity infection (MOI) expressing green fluorescent protein (GFP) or miR-199 transgene added surface Results AAV6 proved most suitable serotype 20,000 MOI efficient dose, these conditions proven not affect contractility have highest transduction penetrability efficiency. This exhibited preferential cardiomyocytes stromal cells (40% both) rat LMS, with lower efficiency endothelial cells, (20% transduction). contrast, showed higher myofibroblasts. Treatment miR-199a significantly increased active force overstretched downregulated expression its target genes, affected proliferative capacity Conclusion can model therapies their protocol adapted obtained hearts. With relevance, this would accelerate preclinical studies novel failure. Funding Acknowledgement Type funding sources: Foundation. Main source(s): British Heart Foundation