title: Targeting of the prostacyclin specific IP1 receptor in lungs with molecular conjugates comprising prostaglandin I2 analogues.
abstract: Molecular conjugates comprising targeting ligands hold great promise for site-specific gene delivery to distant tumors and individual organs including the lung. Here we show that prostaglandin I2 analogues can be used to improve gene transfer efficiency of polyethylenimine (PEI) gene vectors on bronchial and alveolar epithelial cells in vitro and lungs of mice in vivo. Prostacyclin (IP1) receptor expression was confirmed in pulmonary epithelial cell lines by western blot. Iloprost (ILO) and treprostinil (TRP), two prostaglandin I2 analogues, were conjugated to fluorescein-labeled BSA (FLUO-BSA) and compared for IP1 receptor binding/uptake in different lung cell lines. Binding of FLUO-BSA-ILO was 2-4-fold higher than for FLUO-BSA-TRP and could be specifically inhibited by free ILO and IP1 receptor antagonist CAY10449. Internalization of FLUO-BSA-ILO was confirmed by confocal microscopy. Molecular conjugates of PEI and ILO (PEI-g-ILO) were synthesized with increasing coupling degree (F(ILO) (ILO:PEI) = 2, 5, 8, 16) and analyzed for DNA binding, particle formation and transfection efficiency. At optimized conditions (N/P 4, F(ILO) = 5), gene expression using PEI-g-ILO was significantly up to 46-fold higher than for PEI gene vectors and specifically inhibited by CAY10449. Gene expression in the lungs of mice after aerosol delivery was 14-fold higher with PEI-g-ILO F(ILO) = 5 than for PEI. We suggest that targeting of IP1 receptor using ILO represents a promising approach to improve pulmonary gene transfer.
authors.affiliation: Department of Pediatrics, Ludwig-Maximilians-University Munich, 80337 Munich, Germany; Department of Pharmacy, Free University of Berlin, 14166 Berlin, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Geiger
authors.forename: Manish K
authors.initials: MK
authors.lastname: Aneja
authors.forename: Günther
authors.initials: G
authors.lastname: Hasenpusch
authors.forename: Gülnihal
authors.initials: G
authors.lastname: Yüksekdag
authors.forename: Grit
authors.initials: G
authors.lastname: Kummerlöwe
authors.forename: Burkhard
authors.initials: B
authors.lastname: Luy
authors.forename: Tina
authors.initials: T
authors.lastname: Romer
authors.forename: Ulrich
authors.initials: U
authors.lastname: Rothbauer
authors.forename: Carsten
authors.initials: C
authors.lastname: Rudolph
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D002460:Cell Line; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D011464:Epoprostenol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005260:Female; D019793:Fluorescein / Q000378:metabolism; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D016285:Iloprost / Q000378:metabolism / Q000494:pharmacology; D008024:Ligands; D008168:Lung / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D009928:Organ Specificity / Q000187:drug effects; D011094:Polyethyleneimine / Q000378:metabolism; D044006:Receptors, Epoprostenol / Q000378:metabolism*; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine / Q000378:metabolism; D014162:Transfection
chemical_list: D008024:Ligands; D044006:Receptors, Epoprostenol; D012710:Serum Albumin, Bovine; D011094:Polyethyleneimine; D011464:Epoprostenol; D016285:Iloprost; C427248:treprostinil; D019793:Fluorescein