Glutaredoxin Protects Cerebellar Granule Neurons from Dopamine-induced Apoptosis by Activating NF-κB via Ref-1

• Published in: The Journal of biological chemistry 2001-01, Vol.276 (2), p.1335-1344
• Main Authors: Daily, Dvorah, Vlamis-Gardikas, Alexios, Offen, Daniel, Mittelman, Leonid, Melamed, Eldad, Holmgren, Arne, Barzilai, Ari
• Format: Article
• Language: English
• Subjects: Amino Acid Substitution; Animals; Animals, Newborn; Apoptosis - drug effects; Apoptosis - physiology; Bacterial Proteins - pharmacology; Carbon-Oxygen Lyases - metabolism; Cells, Cultured; Cerebellum - cytology; DNA Repair; DNA-(Apurinic or Apyrimidinic Site) Lyase; Dopamine - pharmacology; Endodeoxyribonucleases - metabolism; Escherichia coli; Glutaredoxin; Glutaredoxins; Humans; I^KB protein; IB protein; Medicin och hälsovetenskap; Mice; Mice, Inbred BALB C; Mutagenesis, Site-Directed; Neurons - cytology; Neurons - drug effects; Neurons - physiology; NF-^KB protein; NF-kappa B - metabolism; Oxidoreductases; Protein Transport - drug effects; Proteins - chemistry; Proteins - genetics; Proteins - pharmacology; Recombinant Proteins - pharmacology; Ref-1 protein
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M008121200

The neurotransmitter dopamine (DA) induces apoptosis via its oxidative metabolites. This study shows that glutaredoxin 2 (Grx2) from Escherichia coli and human glutaredoxin could protect cerebellar granule neurons from DA-induced apoptosis. E. coli Grx2, which catalyzes glutathione-disulfide oxidoreduction via its -Cys-Pro-Tyr-Cys- active site, penetrates into cerebellar granule neurons and exerts its activity via NF-κB activation. Analysis of single and double cysteine to serine substitutions in the active site of Grx2 showed that both cysteine residues were essential for activity. Although DA significantly reduced NF-κB binding activity, Grx2 could stimulate the binding of NF-κB to DNA by: (i) translocating NF-κB from the cytoplasm to the nucleus after promoting the phosphorylation and degradation of I-κBα, and (ii) activating the binding of pre existing nuclear NF-κB. The DNA binding activity of NF-κB itself was essential for neuronal survival. Overexpression of I-κB dominant negative gene (I-κB-ΔN) in granule neurons significantly reduced their viability, irrespective of the presence of Grx2. Ref-1 expression was down-regulated by DA but up-regulated by Grx2, while treatment of neurons with Ref-1 antisense oligonucleotide reduced the ability of Grx2 to activate NF-κB binding activity. These results show that Grx2 exerts its anti apoptotic activity through the activation of Ref-1, which then activates NF-κB.