title: Opposing roles of syndecan-1 and syndecan-2 in polyethyleneimine-mediated gene delivery.
abstract: Polyethyleneimines (PEIs) are efficient non-viral vectors for gene transfer. Heparan sulfate proteoglycans have been proposed to be the cell-surface receptors for PEI.DNA complexes (polyplexes). Here, we investigated if syndecan-1 (SDC1) and syndecan-2 (SDC2) are involved in PEI-mediated transfection. Following addition of polyplexes to HEK293 cells, green fluorescent protein-tagged SDCs rapidly formed clusters with PEI that were dependent of lipid raft integrity. However, although SDC1 overexpression slightly enhanced PEI-mediated gene expression, SDC2 dramatically inhibited it. Confocal microscopy analysis showed that SDC1.polyplex endocytosis occurred within minutes after addition of polyplexes, whereas SDC2.polyplex endocytosis took hours. Expression of SDC1 cytoplasmic deletion mutants revealed that the SDC1 cytoplasmic tail is required for gene expression, but not for clustering or endocytosis, whereas overexpression of SDC1/SDC2 chimeras showed that the SDC2 ectodomain is responsible for the inhibitory effect on gene transfer. This study provides evidence that SDCs may have opposing effects on PEI-mediated transfection.
authors.affiliation: Animal Cell Technology Group, Bioprocess Sector, Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec H4P 2R2, Canada.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Paris
authors.forename: Alina
authors.initials: A
authors.lastname: Burlacu
authors.forename: Yves
authors.initials: Y
authors.lastname: Durocher
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D002460:Cell Line; D004705:Endocytosis / Q000502:physiology; D015870:Gene Expression; D006801:Humans; D011094:Polyethyleneimine / Q000737:chemistry*; D017434:Protein Structure, Tertiary / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D017384:Sequence Deletion / Q000235:genetics; D053668:Syndecan-1 / Q000737:chemistry* / Q000235:genetics; D053669:Syndecan-2 / Q000737:chemistry* / Q000235:genetics; D014162:Transfection / Q000379:methods
chemical_list: D011993:Recombinant Fusion Proteins; C508241:SDC1 protein, human; C508245:SDC2 protein, human; D053668:Syndecan-1; D053669:Syndecan-2; D011094:Polyethyleneimine