title: PKC delta and NADPH oxidase in retinoic acid-induced neuroblastoma cell differentiation.
abstract: The role of reactive oxygen species (ROS) in the regulation of signal transduction processes has been well established in many cell types and recently the fine tuning of redox signalling in neurons received increasing attention. With regard to this, the involvement of NADPH oxidase (NOX) in neuronal pathophysiology has been proposed but deserves more investigation. In the present study, we used SH-SY5Y neuroblastoma cells to analyse the role of NADPH oxidase in retinoic acid (RA)-induced differentiation, pointing out the involvement of protein kinase C (PKC) delta in the activation of NOX. Retinoic acid induces neuronal differentiation as revealed by the increased expression of MAP2, the decreased cell doubling rate, and the gain in neuronal morphological features and these events are accompanied by the increased expression level of PKC delta and p67(phox), one of the components of NADPH oxidase. Using DPI to inhibit NOX activity we show that retinoic acid acts through this enzyme to induce morphological changes linked to the differentiation. Moreover, using rottlerin to inhibit PKC delta or transfection experiments to overexpress it, we show that retinoic acid acts through this enzyme to induce MAP2 expression and to increase p67(phox) membrane translocation leading to NADPH oxidase activation. These findings identify the activation of PKC delta and NADPH oxidase as crucial steps in RA-induced neuroblastoma cell differentiation.
authors.affiliation: Department of Experimental Medicine, University of Genoa, Italy. paonit@medicina.unige.it
authors.forename: Mariapaola
authors.initials: M
authors.lastname: Nitti
authors.forename: Anna Lisa
authors.initials: AL
authors.lastname: Furfaro
authors.forename: Claudia
authors.initials: C
authors.lastname: Cevasco
authors.forename: Nicola
authors.initials: N
authors.lastname: Traverso
authors.forename: Umberto Maria
authors.initials: UM
authors.lastname: Marinari
authors.forename: Maria Adelaide
authors.initials: MA
authors.lastname: Pronzato
authors.forename: Cinzia
authors.initials: C
authors.lastname: Domenicotti
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects* / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D009447:Neuroblastoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D051745:Protein Kinase C-delta / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; C489788:MAP2 protein, human; D008869:Microtubule-Associated Proteins; D010750:Phosphoproteins; D012333:RNA, Messenger; C079789:neutrophil cytosol factor 67K; D014212:Tretinoin; D051745:Protein Kinase C-delta