title: Megalin-mediated specific uptake of chitosan/siRNA nanoparticles in mouse kidney proximal tubule epithelial cells enables AQP1 gene silencing.
abstract: RNAi-based strategies provide a great therapeutic potential for treatment of various human diseases including kidney disorders, but face the challenge of in vivo delivery and specific targeting. The chitosan delivery system has previously been shown to target siRNA specifically to the kidneys in mice when administered intravenously. Here we confirm by 2D and 3D bioimaging that chitosan formulated siRNA is retained in the kidney for more than 48 hours where it accumulates in proximal tubule epithelial cells (PTECs), a process that was strongly dependent on the molecular weight of chitosan. Chitosan/siRNA nanoparticles, administered to chimeric mice with conditional knockout of the megalin gene, distributed almost exclusively in cells that expressed megalin, implying that the chitosan/siRNA particle uptake was mediated by a megalin-dependent endocytotic pathway. Knockdown of the water channel aquaporin 1 (AQP1) by up to 50% in PTECs was achieved utilizing the systemic i.v. delivery of chitosan/AQP1 siRNA in mice. In conclusion, specific targeting PTECs with the chitosan nanoparticle system may prove to be a useful strategy for knockdown of specific genes in PTECs, and provides a potential therapeutic strategy for treating various kidney diseases.
authors.affiliation: 1. The Interdisciplinary Nanoscience Center (iNANO) and Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.affiliation: 1. The Interdisciplinary Nanoscience Center (iNANO) and Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.
authors.forename: San
authors.initials: S
authors.lastname: Hein
authors.affiliation: 2. Department of Biomedicine, Aarhus University, Aarhus C, Denmark;
authors.forename: Frederik
authors.initials: F
authors.lastname: Dagnæs-Hansen
authors.affiliation: 2. Department of Biomedicine, Aarhus University, Aarhus C, Denmark; ; 3. MEMBRANES, Aarhus University, Aarhus C, Denmark;
authors.forename: Kathrin
authors.initials: K
authors.lastname: Weyer
authors.affiliation: 1. The Interdisciplinary Nanoscience Center (iNANO) and Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.
authors.forename: Chuanxu
authors.initials: C
authors.lastname: Yang
authors.affiliation: 2. Department of Biomedicine, Aarhus University, Aarhus C, Denmark; ; 3. MEMBRANES, Aarhus University, Aarhus C, Denmark;
authors.forename: Rikke
authors.initials: R
authors.lastname: Nielsen
authors.affiliation: 2. Department of Biomedicine, Aarhus University, Aarhus C, Denmark; ; 3. MEMBRANES, Aarhus University, Aarhus C, Denmark;
authors.forename: Erik I
authors.initials: EI
authors.lastname: Christensen
authors.affiliation: 2. Department of Biomedicine, Aarhus University, Aarhus C, Denmark; ; 3. MEMBRANES, Aarhus University, Aarhus C, Denmark; ; 4. Center for Interactions of Proteins in Epithelial Transport, Aarhus University, Aarhus C, Denmark.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Fenton
authors.affiliation: 1. The Interdisciplinary Nanoscience Center (iNANO) and Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Kjems
mesh_terms: D000818:Animals; D051398:Aquaporin 1 / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D048271:Chitosan / Q000737:chemistry / Q000493:pharmacokinetics*; D004285:Dogs; D004705:Endocytosis; D004847:Epithelial Cells / Q000378:metabolism; D055785:Gene Knockdown Techniques / Q000379:methods*; D007687:Kidney Tubules, Proximal / Q000166:cytology* / Q000378:metabolism; D026561:Low Density Lipoprotein Receptor-Related Protein-2 / Q000502:physiology*; D061985:Madin Darby Canine Kidney Cells; D018345:Mice, Knockout; D008970:Molecular Weight; D053758:Nanoparticles; D009928:Organ Specificity; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000737:chemistry / Q000235:genetics / Q000493:pharmacokinetics*; D014162:Transfection
chemical_list: C496021:Aqp1 protein, mouse; D026561:Low Density Lipoprotein Receptor-Related Protein-2; D034741:RNA, Small Interfering; D051398:Aquaporin 1; D048271:Chitosan
keywords: aquaporin 1; chitosan; megalin; optical imaging.; renal targeting; siRNA