Electroporation- and Mechanical Ventilation-Mediated Gene Transfer to the Lung

Our lab has previously demonstrated that cytoplasmic trafficking and subsequent nuclear entry of non-viral plasmid DNA can be significantly enhanced through the application of cyclic stretch following transfection in vitro (1,2). Here, we demonstrate that cyclic stretching of the murine lung using ventilation immediately following the endotracheal administration and transthoracic electroporation of plasmid DNA increases exogenous gene expression up to 4-fold over Our mice that were not ventilated after plasmid administration and transfection via electroporation in vivo. This increase is time and sequence specific (i.e. the ventilation must occur immediately after the transfection event). The ventilation-enhanced gene transfer is also amplitude-dependent, confirming similar studies completed in vitro, and is mediated, at least in part, through the cytoplasmic tubulin deacetylase, HDAC6. Using immunohistochemistry, we demonstrate that this increase in expression is due to an increase in the number of cells expressing the exogenous protein rather than an increase in the amount of protein produced per cell. These studies demonstrate the potential mechanical stimulation has in vivo in significantly increasing non-viral DNA gene expression, and may ultimately pave the way for more successful clinical trials using this type of therapy in the future.