140. Hydrodynamics-based transfection of the liver: entrance into hepatocytes of DNA that causes expression, takes place very early after injection

The mechanism of gene transfer into hepatocytes by the hydrodynamics-based transfection procedure is not clearly understood. It has been shown that after an hydrodynamic injection, a large proportion of plasmid DNA remains intact in the liver where it is bound to plasma membrane and suggested that this DNA could be responsible of the efficiency of the transfection (Lecocq M et al, J of Gene Med, 5, 142-156, 2003). We have investigated the problem by giving to the mice an hydrodynamic injection of isotonic NaCl, followed at different time intervals by a conventional injection of DNA, cold or labelled with 35S, with cDNA of luciferase as a reporter gene. Then, we have determined the consequences of that dual injection on luciferase expression and on DNA uptake by the liver and its intracellular fate. By such experiments, it is possible to establish the time dependency of the induction of liver changes caused by an hydrodynamic injection on the one hand and the expression and DNA uptake and fate on the other hand.