title: Attachment of cell-binding ligands to arginine-rich cell-penetrating peptides enables cytosolic translocation of complexed siRNA.
abstract: Cell-penetrating peptides (CPPs), such as nona-arginine (9R), poorly translocate siRNA into cells. Our studies demonstrate that attaching 9R to ligands that bind cell surface receptors quantitatively increases siRNA uptake and importantly, allows functional delivery of complexed siRNA. The mechanism involved accumulation of ligand-9R:siRNA microparticles on the cell membrane, which induced transient membrane inversion at the site of ligand-9R binding and rapid siRNA translocation into the cytoplasm. siRNA release also occurred late after endocytosis when the ligand was attached to the L isoform of 9R, but not the protease-resistant 9DR, prolonging mRNA knockdown. This critically depended on endosomal proteolytic activity, implying that partial CPP degradation is required for endosome-to-cytosol translocation. The data demonstrate that ligand attachment renders simple polycationic CPPs effective for siRNA delivery by restoring their intrinsic property of translocation.
authors.affiliation: Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: Skye
authors.initials: S
authors.lastname: Zeller
authors.affiliation: Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Bioengineering and Institute of Nanoscience and Technology, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Chang Seon
authors.initials: CS
authors.lastname: Choi
authors.affiliation: Department of Microbial Pathogenesis, Yale University, New Haven, CT 06510, USA.
authors.forename: Pradeep D
authors.initials: PD
authors.lastname: Uchil
authors.affiliation: Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Bioengineering and Institute of Nanoscience and Technology, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Hong-Seok
authors.initials: HS
authors.lastname: Ban
authors.affiliation: Department of Biomedical Engineering, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: Alyssa
authors.initials: A
authors.lastname: Siefert
authors.affiliation: Department of Biomedical Engineering, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: Tarek M
authors.initials: TM
authors.lastname: Fahmy
authors.affiliation: Department of Microbial Pathogenesis, Yale University, New Haven, CT 06510, USA.
authors.forename: Walther
authors.initials: W
authors.lastname: Mothes
authors.affiliation: Department of Bioengineering and Institute of Nanoscience and Technology, Hanyang University, Seoul 133-791, South Korea. Electronic address: sangkyunglee@hanyang.ac.kr.
authors.forename: Sang-Kyung
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06510, USA. Electronic address: priti.kumar@yale.edu.
authors.forename: Priti
authors.initials: P
authors.lastname: Kumar
mesh_terms: D001120:Arginine / Q000737:chemistry*; D015704:CD4 Antigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D057846:Cell-Penetrating Peptides / Q000737:chemistry / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism; D006801:Humans; D008024:Ligands; D018613:Microscopy, Confocal; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D059008:Time-Lapse Imaging; D014162:Transfection
chemical_list: D015704:CD4 Antigens; D057846:Cell-Penetrating Peptides; D008024:Ligands; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C000606290:SOD1 protein, human; D001120:Arginine; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1