Up-regulation of cytosolic phospholipase A2alpha expression by N,N-diethyldithiocarbamate in PC12 cells; involvement of reactive oxygen species and nitric oxide.
Disulfiram (an alcohol-aversive drug) and related compounds are known to provoke several side effects involving behavioral and neurological complications. N,N-diethyldithiocarbamate (DDC) is considered as one of the main toxic species of disulfiram and acts as an inhibitor of superoxide dismutase. Since arachidonic acid (AA) formation is regulated by reactive oxygen species (ROS) and related to toxicity in neuronal cells, we investigated the effects of DDC on AA release and expression of the alpha type of cytosolic phospholipase A(2) (cPLA(2)alpha) in PC12 cells. Treatment with 80-120 microM DDC that causes a moderate increase in ROS levels without cell toxicity stimulated cPLA(2)alpha mRNA and its protein expression. The expression was mediated by extracellular-signal-regulated kinase (ERK1/2), one of the mitogen-activated protein kinases. Treatment with N(G) nitro-L-arginine methyl ester (an inhibitor of nitric oxide synthase, 1 mM) and oxy-hemoglobin (a scavenger of nitric oxide, 2 mg/mL) abolished the DDC-induced responses (ERK1/2 phosphorylation and cPLA(2)alpha expression). We also showed DDC-induced up-regulation of the mRNA expression of lipocortin 1, an inhibitor of PLA(2). Furthermore, DDC treatment of the cells enhanced Ca(2+)-ionophore-induced AA release in 30 min, although the effect was limited. Changes in AA metabolism in DDC-treated cells may have a potential role in mediating neurotoxic actions of disulfiram. In this study, we show the first to demonstrate the up-regulation of cPLA(2)alpha expression by DDC treatment in neuronal cells.
Akiyama
Nobuteru
N
Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chiba, Japan.
Nabemoto
Maiko
M
Hatori
Yoshio
Y
Nakamura
Hiroyuki
H
Hirabayashi
Tetsuya
T
Fujino
Hiromichi
H
Saito
Takeshi
T
Murayama
Toshihiko
T
D000818:Animals; D017305:Annexin A1 / Q000235:genetics / Q000378:metabolism; D000998:Antiviral Agents / Q000494:pharmacology*; D016718:Arachidonic Acid / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology; D004050:Ditiocarb / Q000494:pharmacology*; D004336:Drug Antagonism; D015870:Gene Expression / Q000187:drug effects; D054513:Group IV Phospholipases A2; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D010108:Oxyhemoglobins / Q000494:pharmacology; D016716:PC12 Cells / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D010741:Phospholipases A / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D015854:Up-Regulation
D017305:Annexin A1; D000998:Antiviral Agents; D010108:Oxyhemoglobins; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D016718:Arachidonic Acid; D009569:Nitric Oxide; D004050:Ditiocarb; D013482:Superoxide Dismutase; D048052:Mitogen-Activated Protein Kinase 3; D010741:Phospholipases A; D054513:Group IV Phospholipases A2; D019331:NG-Nitroarginine Methyl Ester