title: Intracellular localization of lipoplexed siRNA in vascular endothelial cells of different mouse tissues.
abstract: Liposomally formulated siRNA can be used for RNAi applications in vivo. Intravenous bolus administration of lipoplexed siRNA has been shown to reduce gene expression in the vascular endothelium. Here, we applied immunofluorescence staining for different endothelial markers (PECAM-1, CD34, laminin) on paraffin sections to compare the respective expression pattern with the intracellular localization of intravenously administered, fluorescently labeled siRNA (siRNA-Cy3-lipoplex). By confocal microscopy, lipoplexed siRNA-Cy3 was detected inside vascular endothelial cells in vivo, which where identified with co-staining of endothelial markers. Consequently, the finding of intracellular siRNA uptake by vascular endothelial cells correlated with RNAi based specific protein reduction in situ as revealed by PECAM-1 specific immunofluorescence staining in lung tissue sections. Therefore, by using a cell biological approach these in situ data emphasize the functional uptake of liposomal siRNA molecules in vascular endothelial cells of different mouse tissues as indicated in our previous molecular study.
authors.affiliation: Silence Therapeutics AG, 13125 Berlin, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Aleku
authors.forename: Gerald
authors.initials: G
authors.lastname: Fisch
authors.forename: Kristin
authors.initials: K
authors.lastname: Möpert
authors.forename: Oliver
authors.initials: O
authors.lastname: Keil
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Arnold
authors.forename: Jörg
authors.initials: J
authors.lastname: Kaufmann
authors.forename: Ansgar
authors.initials: A
authors.lastname: Santel
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics; D018952:Antigens, CD34 / Q000032:analysis; D015820:Cadherins / Q000235:genetics; D002232:Carbocyanines / Q000737:chemistry; D042783:Endothelial Cells / Q000737:chemistry / Q000378:metabolism*; D004729:Endothelium, Lymphatic / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006023:Glycoproteins / Q000032:analysis; D007150:Immunohistochemistry; D042541:Intracellular Space / Q000737:chemistry / Q000378:metabolism*; D007797:Laminin / Q000032:analysis; D008081:Liposomes; D008099:Liver / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D008168:Lung / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D026901:Membrane Transport Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D009206:Myocardium / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D051059:PTEN Phosphohydrolase / Q000235:genetics; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D015820:Cadherins; D002232:Carbocyanines; D006023:Glycoproteins; D007797:Laminin; D008081:Liposomes; D026901:Membrane Transport Proteins; D051059:PTEN Phosphohydrolase; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D034741:RNA, Small Interfering; D040301:Vascular Endothelial Growth Factor Receptor-2; D000099152:Cadherin 5; C492273:LYVE1 protein, mouse; C089187:cyanine dye 3; C085321:cyanine dye 5; C487757:Pten protein, mouse