title: Pyrrolidine dithiocarbamate activates the Nrf2 pathway in astrocytes.
abstract: BACKGROUND
  Endogenous defense against oxidative stress is controlled by nuclear factor erythroid 2-related factor 2 (Nrf2). The normal compensatory mechanisms to combat oxidative stress appear to be insufficient to protect against the prolonged exposure to reactive oxygen species during disease. Counterbalancing the effects of oxidative stress by up-regulation of Nrf2 signaling has been shown to be effective in various disease models where oxidative stress is implicated, including Alzheimer's disease. Stimulation of Nrf2 signaling by small-molecule activators is an appealing strategy to up-regulate the endogenous defense mechanisms of cells.
  
  
  METHODS
  Here, we investigate Nrf2 induction by the metal chelator and known nuclear factor-κB inhibitor pyrrolidine dithiocarbamate (PDTC) in cultured astrocytes and neurons, and mouse brain. Nrf2 induction is further examined in cultures co-treated with PDTC and kinase inhibitors or amyloid-beta, and in Nrf2-deficient cultures.
  
  
  RESULTS
  We show that PDTC is a potent inducer of Nrf2 signaling specifically in astrocytes and demonstrate the critical role of Nrf2 in PDTC-mediated protection against oxidative stress. This induction appears to be regulated by both Keap1 and glycogen synthase kinase 3β. Furthermore, the presence of amyloid-beta magnifies PDTC-mediated induction of endogenous protective mechanisms, therefore suggesting that PDTC may be an effective Nrf2 inducer in the context of Alzheimer's disease. Finally, we show that PDTC increases brain copper content and glial expression of heme oxygenase-1, and decreases lipid peroxidation in vivo, promoting a more antioxidative environment.
  
  
  CONCLUSIONS
  PDTC activates Nrf2 and its antioxidative targets in astrocytes but not neurons. These effects may contribute to the neuroprotection observed for PDTC in models of Alzheimer's disease.
authors.affiliation: Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia. jliddell@unimelb.edu.au.|Mental Health Research Institute of Victoria, Parkville, Victoria, Australia. jliddell@unimelb.edu.au.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Liddell
authors.affiliation: Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. sarka.lehtonen@uef.fi.
authors.forename: Sarka
authors.initials: S
authors.lastname: Lehtonen
authors.affiliation: Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia. cduncan@unimelb.edu.au.|Mental Health Research Institute of Victoria, Parkville, Victoria, Australia. cduncan@unimelb.edu.au.
authors.forename: Clare
authors.initials: C
authors.lastname: Duncan
authors.affiliation: Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. velta.keksa-goldsteine@uef.fi.
authors.forename: Velta
authors.initials: V
authors.lastname: Keksa-Goldsteine
authors.affiliation: Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. anna-liisa.levonen@uef.fi.
authors.forename: Anna-Liisa
authors.initials: AL
authors.lastname: Levonen
authors.affiliation: Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. gundars.goldsteins@uef.fi.
authors.forename: Gundars
authors.initials: G
authors.lastname: Goldsteins
authors.affiliation: Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. tarja.malm@uef.fi.
authors.forename: Tarja
authors.initials: T
authors.lastname: Malm
authors.affiliation: Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia. arwhite@unimelb.edu.au.|Mental Health Research Institute of Victoria, Parkville, Victoria, Australia. arwhite@unimelb.edu.au.
authors.forename: Anthony R
authors.initials: AR
authors.lastname: White
authors.affiliation: Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. jari.koistinaho@uef.fi.
authors.forename: Jari
authors.initials: J
authors.lastname: Koistinaho
authors.affiliation: Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. katja.kanninen@uef.fi.
authors.forename: Katja M
authors.initials: KM
authors.lastname: Kanninen
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000975:Antioxidants / Q000494:pharmacology*; D001253:Astrocytes / Q000187:drug effects*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002466:Cell Nucleolus / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects; D010105:Oxygenases / Q000378:metabolism; D011759:Pyrrolidines / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*; D013859:Thiocarbamates / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D011759:Pyrrolidines; D013859:Thiocarbamates; C020972:pyrrolidine dithiocarbamic acid; D010105:Oxygenases; D005721:Glutamate-Cysteine Ligase