Transient cytoskeletal alterations after SOD1 depletion in neuroblastoma cells.
We have studied the effects of superoxide production after Cu,Zn superoxide dismutase (SOD1) down-regulation by RNA interference. We demonstrated that SOD1 depletion induced, only in neuroblastoma cells, a decrease in actin and beta-tubulin content and accumulation of neurofilament light chain and Tau proteins. Alterations of cell morphology and the microfilament network were also observed, together with the up-regulation of the Cdk5/p35 pathway, which is involved in the regulation of actin polymerization. The decrease of filamentous actin was transient and was recovered through the activation of p38/Hsp27 MAPK pathway, as well as after treatment with N-acetyl-L-cysteine. The importance of p38 in the recovery of cytoskeleton was confirmed by experiments carried out in the presence of its inhibitor SB203580, which induced cell death. Our data demonstrate that SOD1 is essential for the preservation of cytoskeleton integrity, by maintaining physiological concentration of reactive oxygen species and inhibiting the activation of the neuronal specific Cdk5/p35 pathway.
Vigilanza
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Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, Rome, Italy.
Aquilano
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Rotilio
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Ciriolo
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MR
D000199:Actins / Q000378:metabolism; D017209:Apoptosis; D045744:Cell Line, Tumor; D048430:Cell Shape; D051360:Cyclin-Dependent Kinase 5 / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D015536:Down-Regulation; D004789:Enzyme Activation; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D009447:Neuroblastoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D013481:Superoxides / Q000378:metabolism; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D000199:Actins; D006360:Heat-Shock Proteins; D034741:RNA, Small Interfering; C000606290:SOD1 protein, human; D013481:Superoxides; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D051360:Cyclin-Dependent Kinase 5; D017346:Protein Serine-Threonine Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D038362:Glycogen Synthase Kinase 3; C080888:tau-protein kinase