title: Cationic lipids involved in gene transfer mobilize intracellular calcium.
abstract: Cationic lipids are efficient tools to introduce nucleic acids and proteins into cells. Elucidation of the mechanism and cellular pathways associated with such transport has been relatively tedious, even though significant progress has been made in the characterization of the intracellular trafficking of lipid/DNA complexes. Surprisingly little is known about the effects of these delivery vectors on cell functioning. In this report, we show that both cationic lipids and cationic lipid/DNA complexes mobilize the intracellular calcium. Removal of extracellular calcium did not significantly abolish this effect and preincubating cells with thapsigargin led to a decrease in [Ca2+]i, indicating that calcium was released mainly from internal calcium stores sensitive to thapsigargin. Pretreatment of the cells with the phospholipase C inhibitor U73122, blocked the [Ca2+]i rise, suggesting an inositol dependent mechanism.
authors.affiliation: Laboratory of Structure and Function of Biological Membranes, Center of Structural Biology and Bioinformatics, Université Libre de Bruxelles, Brussels, Belgium. mouali@ulb.ac.be
authors.forename: Mustapha
authors.initials: M
authors.lastname: Ouali
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Ruysschaert
authors.forename: Caroline
authors.initials: C
authors.lastname: Lonez
authors.forename: Michel
authors.initials: M
authors.lastname: Vandenbranden
mesh_terms: D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D002412:Cations / Q000737:chemistry / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000737:chemistry / Q000494:pharmacology; D005822:Genetic Vectors / Q000378:metabolism; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D020014:K562 Cells; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008081:Liposomes; D008954:Models, Biological; D011760:Pyrrolidinones / Q000737:chemistry / Q000494:pharmacology; D019284:Thapsigargin / Q000737:chemistry / Q000494:pharmacology; D014162:Transfection; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D002412:Cations; D004791:Enzyme Inhibitors; D004963:Estrenes; D007295:Inositol Phosphates; D008055:Lipids; D008081:Liposomes; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D019284:Thapsigargin; D010738:Type C Phospholipases; D002118:Calcium