Enhanced transgene expression in rat brain cell cultures with a disulfide-containing cationic lipid

The transfection efficiency of a disulfide-containing cationic lipid, 1',2' dioleoyl-sn-glycero-3'-succinyl-2-hydroxyethyl disulfide ornithine conjuga te (DOGSDSO) and its non-disulfide analog (DOGSHDO) were compared in neuron al, astroglial and microglial cultures from newborn rat cerebral cortex. We hypothesized that the relatively high intracellular concentrations of redu ctive substances in the cytoplasm may help to cleave the reversible disulfi de bond in DOGSDSO, thus increasing free DNA and decreasing toxicity due to rapid degradation of the lipid. We have demonstrated through mass spectrom etric analysis that a reductive compound, e.g: dithiothreitol (DTT) could d egrade the disulfide lipid. DOGSDSO was more efficient at transfecting each type of:brain cell than were the non-disulfide DOGSHDO and DOTAP (1,2-diol eoyl-3-trimethyl-ammonium-propane liposomes. These results demonstrate that disulfide-containing cationic liposomes facilitate gene transfection in cu ltured rat brain: cells. (C) 1999 Elsevier Science Ireland Ltd. Ail rights reserved.