Pyrrolidine dithiocarbamate inhibits TNF-alpha-dependent activation of NF-kappaB by increasing intracellular copper level in human aortic smooth muscle cells.
Pyrrolidine dithiocarbamate (PDTC) is a metal-chelating compound that acts as antioxidant or pro-oxidant and is widely used to study redox regulation of cell function. In the present study, we investigated effects of PDTC and another antioxidant, N-acetyl-l-cysteine (NAC), on TNF-alpha-dependent activation of NF-kappaB in human aortic smooth muscle cells (HASMC). Treatment of the cells with TNF-alpha induced the activation of p65/p50 heterodimer NF-kappaB and increased the mRNA levels of monocyte chemoattractant protein (MCP)-1. Pretreatment with PDTC markedly suppressed the NF-kappaB activation and expression of MCP-1 by inhibiting IkappaB-alpha degradation. In contrast, NAC had no effect. PDTC concomitantly increased the intracellular levels of copper, and bathocuproinedisulfonic acid, a non-cell-permeable chelator of Cu(1+), inhibited the PDTC-induced increase in intracellular copper level and reversed the PDTC effects on IkappaB-alpha, NF-kappaB, and MCP-1. These results indicate that TNF-alpha-dependent expression of MCP-1 in HASMC is tightly regulated by NF-kappaB and that intracellular copper level is crucial for the TNF-alpha-dependent activation of NF-kappaB in HASMC.
Iseki
A
A
Department of Endocrinology and Metabolism, Research Institute of Environmental Medicine, Nagoya, 464-8601, Japan.
Kambe
F
F
Okumura
K
K
Niwata
S
S
Yamamoto
R
R
Hayakawa
T
T
Seo
H
H
D000111:Acetylcysteine / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology*; D001011:Aorta / Q000378:metabolism; D002478:Cells, Cultured; D003300:Copper / Q000378:metabolism*; D004336:Drug Antagonism; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D011759:Pyrrolidines / Q000494:pharmacology*; D013859:Thiocarbamates / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D000975:Antioxidants; D016166:Free Radical Scavengers; D016328:NF-kappa B; D011759:Pyrrolidines; D013859:Thiocarbamates; D014409:Tumor Necrosis Factor-alpha; C020972:pyrrolidine dithiocarbamic acid; D003300:Copper; D000111:Acetylcysteine