title: Augmented inhibitory effect of superoxide dismutase on superoxide anion release from macrophages by direct cationization.
abstract: Superoxide dismutase (SOD) was modified into cationized form (Cat-SOD) in order to enhance its pharmacological efficacy based on an electrostatic interaction. The inhibitory effect of Cat-SOD on superoxide anion release from inflammatory macrophages and its cellular interaction were studied in vitro. Cat-SOD exhibited an excellent inhibitory effect on superoxide anion release from the macrophages, and this effect surpassed those of native SOD and SOD modified with mannose (Man-SOD) which is taken up via mannose receptor-mediated endocytosis by macrophages. In the presence of colchicine, a microtubule-disruptive agent, the inhibitory effect of Cat-SOD was slightly impaired, whereas the effect of Man-SOD completely disappeared. The intracellular localization of fluorescein isothiocyanate-labeled SOD, Cat-SOD and Man-SOD observed by confocal laser microscopy supported the difference in their abilities to eliminate superoxide anions. The different sensitivities of Cat-SOD and Man-SOD to colchicine were also confirmed by the confocal laser microscopic images, suggesting their distinct intracellular trafficking pathways in the macrophages. In conclusion, Cat-SOD is desirable for its pharmacological activity, which is probably the result of its ability to be delivered to the vicinity of NADPH-oxidase which locates in the cell membrane and generates superoxide anions.
authors.affiliation: Department of Drug Delivery Research, Faculty of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takagi
authors.forename: M
authors.initials: M
authors.lastname: Kitano
authors.forename: S
authors.initials: S
authors.lastname: Masuda
authors.forename: H
authors.initials: H
authors.lastname: Tokuda
authors.forename: Y
authors.initials: Y
authors.lastname: Takakura
authors.forename: M
authors.initials: M
authors.lastname: Hashida
mesh_terms: D000818:Animals; D002412:Cations / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003959:Diamines / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate; D007205:Indium Radioisotopes; D017737:Macrophages, Peritoneal / Q000201:enzymology / Q000378:metabolism*; D051379:Mice; D013482:Superoxide Dismutase / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism*
chemical_list: D002412:Cations; D003959:Diamines; D007205:Indium Radioisotopes; D013481:Superoxides; D013482:Superoxide Dismutase; D016650:Fluorescein-5-isothiocyanate; C007297:1,6-diaminohexane