title: Over-expression of the Sirt3 sirtuin Protects neuronally differentiated PC12 Cells from degeneration induced by oxidative stress and trophic withdrawal.
abstract: Sirt3 is a mitochondrial sirtuin whose deacetylase activity regulates facets of oxidative metabolic efficiency, anti-oxidative capacity, and intra-mitochondrial signaling. In this study, we tested whether the over-expression of a human Sirt3-myc transgene in differentiated PC12 cells, a model of sympathetic catecholaminergic neurons, would affect the sensitivity of these cells to oxidative stress or trophic withdrawal insults. Expression analysis revealed the Sirt3-myc product was expressed as a 45kDa pro-form, which localized primarily within the cytosol, and a 30kDa processed form that localized predominantly within mitochondria. When subjected to acute glucose deprivation or acute oxygen-glucose deprivation, differentiated PC12 cells over-expressing Sirt3-myc displayed significantly lower levels of cytotoxicity, both at the end of the insult, and at different times following media reperfusion, than cells transfected with a control plasmid. Further, Sirt3-myc over-expression also protected differentiated PC12 cells from apoptosis induced by trophic withdrawal. Collectively, these data indicate that an elevation of Sirt3 is sufficient to protect neuronal PC12 cells from cytotoxic insults, and add to the growing evidence that Sirt3 could be targeted for neuroprotective intervention.
authors.affiliation: Division of Genetics and Development, Toronto Western Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8; Department of Physiology, University of Toronto, Toronto, Ontario, Canada M5T 2S8.
authors.forename: Natalya
authors.initials: N
authors.lastname: Shulyakova
authors.affiliation: Division of Genetics and Development, Toronto Western Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8; Department of Physiology, University of Toronto, Toronto, Ontario, Canada M5T 2S8.
authors.forename: Elena
authors.initials: E
authors.lastname: Sidorova-Darmos
authors.affiliation: Division of Genetics and Development, Toronto Western Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8.
authors.forename: Jamie
authors.initials: J
authors.lastname: Fong
authors.affiliation: Division of Genetics and Development, Toronto Western Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Division of Genetics and Development, Toronto Western Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8; Department of Physiology, University of Toronto, Toronto, Ontario, Canada M5T 2S8.
authors.forename: Linda R
authors.initials: LR
authors.lastname: Mills
authors.affiliation: Division of Genetics and Development, Toronto Western Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8; Department of Physiology, University of Toronto, Toronto, Ontario, Canada M5T 2S8; Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada M5T 2S8; Department of Surgery (Neurosurgery), University of Toronto, Toronto, Ontario, Canada M5S 1A8. Electronic address: jeubanks@uhnres.utoronto.ca.
authors.forename: James H
authors.initials: JH
authors.lastname: Eubanks
mesh_terms: D000818:Animals; D017209:Apoptosis; D003470:Culture Media / Q000494:pharmacology; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism; D008970:Molecular Weight; D009410:Nerve Degeneration / Q000517:prevention & control*; D055495:Neurogenesis; D009474:Neurons / Q000473:pathology*; D018384:Oxidative Stress; D010100:Oxygen / Q000494:pharmacology; D016716:PC12 Cells; D011499:Protein Processing, Post-Translational; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D056566:Sirtuin 3 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D003470:Culture Media; D016895:Culture Media, Serum-Free; D017382:Reactive Oxygen Species; D011993:Recombinant Fusion Proteins; C466093:SIRT3 protein, human; D056566:Sirtuin 3; D005947:Glucose; D010100:Oxygen
keywords: Apoptosis; Glucose deprivation; Mitochondria; Neuroprotection; Sirtuin