RT Journal Article
SR Electronic
T1 Pyrrolidine Dithiocarbamate Inhibits Induction of Immunoproteasome and Decreases Survival in a Rat Model of Amyotrophic Lateral Sclerosis
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 30
OP 37
DO 10.1124/mol.106.028415
VO 71
IS 1
A1 Toni Ahtoniemi
A1 Gundars Goldsteins
A1 Velta Keksa-Goldsteine
A1 Tarja Malm
A1 Katja Kanninen
A1 Antero Salminen
A1 Jari Koistinaho
YR 2007
UL http://molpharm.aspetjournals.org/content/71/1/30.abstract
AB Pyrrolidine dithiocarbamate (PDTC), an inhibitor of nuclear transcription factor κ-B (NF-κB) and an antioxidant, has beneficial effects in animal models of various diseases, including arthritis, brain ischemia, spinal cord injury, Alzheimer's disease, and Duchenne muscular dystrophy. Because inflammation and oxidative damage are also hallmarks of amyotrophic lateral sclerosis (ALS), we studied the effect of oral PDTC treatment on G93A-superoxide dismutase 1 (SOD1) transgenic (TG) rat model of human ALS and observed that PDTC treatment significantly decreases the survival. PDTC treatment evoked the end stage of the disease at 121 ± 21 days, whereas untreated TG animals reached the end stage at 141 ± 13 days (p < 0.01). The DNA binding activity of NF-κB was not altered in G93A-SOD1 TG rats by PDTC treatment. The copper concentration in the spinal cord was increased after PDTC treatment both in G93A-SOD1 TG and wild-type rats, suggesting that increased copper may enhance the neurotoxicity of mutant SOD1. The amount of ubiquitinated proteins were significantly higher and proteasomal activity was decreased in the spinal cords of PDTC-treated TG rats compared with other groups, suggesting that PDTC treatment decreases proteasome function. Immunoblotting and immunocytochemistry showed that the level of immunoproteasome but not constitutive proteasome was increased in glia of G93A-SOD1 TG rats along with disease development. PDTC treatment completely blocked the induction of immunoproteasome expression without affecting constitutive proteasome. These results suggest that PDTC acts as an immunoproteasome inhibitor in mutant SOD1 rats and that immunoproteasome may help the nervous system to cope with deleterious effects of SOD1-G93A mutation. The American Society for Pharmacology and Experimental Therapeutics