title: The role of adenosine receptor and caveolae-mediated endocytosis in oligonucleotide-mediated gene transfer.
abstract: We previously reported the preparation and characterization of ternary nanoparticles with the negative surface charge, which comprises histidine-conjugated polyallylamine (PAA-HIS)/DNA core complex and a single-stranded oligonucleotide outer layer, to transfect various cell lines. As a continued effort, here the investigations on the endocytotic mechanisms involved in the uptake of the oligonucleotide-coated PAA-HIS/DNA complexes are reported. Interestingly, these complexes showed enhanced transfection efficiency only when deoxyadenosine-containing oligonucleotides were deposited on the PAA-HIS/DNA complex surface. The addition of uncomplexed oligonucleotide, free adenosine and adenosine receptor antagonist significantly inhibited the transfection efficiency of oligonucleotide-coated PAA-HIS/DNA complexes. These results indicated that the oligonucleotide-coated PAA-HIS/DNA complexes could specifically recognize adenosine receptors on the cell surface and were taken up by adenosine receptor-mediated process. Uptake and transfection experiments with various endocytic inhibitors suggested that, after receptor/ligand binding, oligonucleotide-coated PAA-HIS/DNA/complexes were mainly internalized via caveolae-mediated pathway to result in effective intracellular processing for gene expression. In conclusion, both adenosine receptor and caveolae-mediated endocytosis play important roles in oligonucleotide-mediated gene transfer.
authors: Institute of Polymer Science and Engineering, National Taiwan University, Taipei, Taiwan.
authors: Yi-Chen
authors: YC
authors: Chung
authors: Ting-Yun
authors: TY
authors: Cheng
authors: Tai-Horng
authors: TH
authors: Young
mesh_terms: D021941:Caveolae / Q000378:metabolism*; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology*; D018014:Gene Transfer Techniques; D006367:HeLa Cells; D006801:Humans; D007035:Hypothermia / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism*; D011073:Polyamines / Q000737:chemistry / Q000378:metabolism; D000071228:Polyelectrolytes; D018047:Receptors, Purinergic P1 / Q000378:metabolism*
chemical_list: D004247:DNA; D009841:Oligonucleotides; D011073:Polyamines; D000071228:Polyelectrolytes; D018047:Receptors, Purinergic P1