The Cu,Zn superoxide dismutase in neuroblastoma SK-N-BE cells is exported by a microvesicles dependent pathway.
The antioxidant enzyme Cu,Zn superoxide dismutase has so far been considered costitutively expressed and exclusively localized into cytosol. In this paper we investigated Cu,Zn superoxide dismutase export in neuroblastoma SK-N-BE cells by flow cytometry analysis, confocal immunofluorescence analysis and enzyme-linked immunosorbed assay. Immunofluorescence analysis shows that the enzyme is exported by microvesicular granules; moreover the treatment of cells with brefeldin A and with 2-deoxy-D-glucose and sodium azide strongly decreases the amount of CuZn superoxide dismutase detected in the medium. Therefore the involvement of ATP-dependent mechanisms, likely including BFA-sensitive intracytoplasmic vesicles in Cu,Zn SOD export from SK-N-BE cells, has to be hypothesized. Microvesicular-mediated Cu,Zn SOD export in neurons could represent a relevant phenomenon able to influence cell excitability that is affected by reactive oxygen species.
Mondola
Paolo
P
Department of Neuroscience and Behavioral Sciences, Section of Physiology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy. mondola@unina.it
Ruggiero
Giuseppina
G
Serù
Rosalba
R
Damiano
Simona
S
Grimaldi
Serena
S
Garbi
Corrado
C
Monda
Marcellino
M
Greco
Dario
D
Santillo
Mariarosaria
M
D015153:Blotting, Western; D020126:Brefeldin A / Q000494:pharmacology; D022162:Cytoplasmic Vesicles / Q000502:physiology*; D003599:Cytoskeleton / Q000378:metabolism; D003847:Deoxyglucose / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D006801:Humans; D008744:Methylamines / Q000494:pharmacology; D009447:Neuroblastoma; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology*; D019810:Sodium Azide / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D004791:Enzyme Inhibitors; D008744:Methylamines; D011500:Protein Synthesis Inhibitors; D020126:Brefeldin A; D019810:Sodium Azide; D003847:Deoxyglucose; C027451:methylamine; D013482:Superoxide Dismutase