Novel biphasic effect of pyrrolidine dithiocarbamate on neuronal cell viability is mediated by the differential regulation of intracellular zinc and copper ion levels, NF-kappaB, and MAP kinases.
Nuclear factor kappaB (NF-kappaB) is a transcription factor involved in the expression of a wide range of genes, most of which code for proteins that play a role in immunity and inflammation. Pyrrolidine dithiocarbamate (PDTC) is a well-known inhibitor of NF-kappaB. Although its mechanism of action is conferred by its antioxidant property, other mechanisms by which PDTC can act as a prooxidant, metal chelator, and free thiol group modulator have recently been suggested. Here we report that PDTC caused a dual effect on cell viability in neuronal rat pheochromocytoma (PC12) cells, depending on its concentration. Increase of intracellular zinc and copper ion levels selectively potentiated the cytotoxic PDTC effect in a dose-dependent manner, and thiol reagents, such as glutathione and N-acetylcysteine, as well as divalent metal-chelating reagents, such as EDTA and bathocuproline disulfonic acid, blocked its cell death effect. The differential effect of PDTC on cell viability correlates well with the inhibition of NF-kappaB activities. In addition, PDTC differentially activated microtubule-associated protein (MAP) kinases, such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), but not p38, depending on its dose, and the coaddition of glutathione (GSH), other antioxidants, and metal ions also modulated their activities. Furthermore, stable Bcl-2 expression blocked the PDTC-induced cell death. These results suggest that the thiol groups and free zinc and copper ion levels are important for the novel biphasic PDTC effect on cell viability, which is associated with the differential activation of NF-kappaB and MAP kinases.
Chung
K C
KC
Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea. kchung@yumc.yonsei.ac.kr
Park
J H
JH
Kim
C H
CH
Lee
H W
HW
Sato
N
N
Uchiyama
Y
Y
Ahn
Y S
YS
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects*; D002614:Chelating Agents / Q000494:pharmacology; D003300:Copper / Q000378:metabolism*; D016895:Culture Media, Serum-Free; D004305:Dose-Response Relationship, Drug; D007477:Ions; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases / Q000187:drug effects / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000187:drug effects* / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D016716:PC12 Cells; D011759:Pyrrolidines / Q000494:pharmacology*; D051381:Rats; D013438:Sulfhydryl Compounds / Q000494:pharmacology; D013859:Thiocarbamates / Q000494:pharmacology*; D015032:Zinc / Q000378:metabolism*
D000975:Antioxidants; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins; D002614:Chelating Agents; D016895:Culture Media, Serum-Free; D007477:Ions; D016328:NF-kappa B; D011759:Pyrrolidines; D013438:Sulfhydryl Compounds; C090468:TP53BP2 protein, human; D013859:Thiocarbamates; C020972:pyrrolidine dithiocarbamic acid; D003300:Copper; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D015032:Zinc