title: D-beta-hydroxybutyrate protects dopaminergic SH-SY5Y cells in a rotenone model of Parkinson's disease.
abstract: It has been postulated that the pathogenesis of Parkinson's disease (PD) is associated with mitochondrial dysfunction. Rotenone, an inhibitor of mitochondrial complex I, provides models of PD both in vivo and in vitro. We investigated the neuroprotective effect of D-beta-hydroxybutyrate (bHB), a ketone body, against rotenone toxicity by using SH-SY5Y dopaminergic neuroblastoma cells. SH-SY5Y cells, differentiated by all-trans-retinoic acid, were exposed to rotenone at concentrations ranging from 0 to 1,000 nM. We evaluated cellular oxidation reduction by the alamarBlue assay, viability by lactate dehydrogenase (LDH) assay, and survival/death ratio by live/dead assays. Exposure to rotenone for 48 hr oxidized cells and decreased their viability and survival rate in a concentration-dependent manner. Pretreatment of cells with 8 mM bHB provided significant protection to SH-SY5Y cells. Whereas rotenone caused the loss of mitochondrial membrane potential, released cytochrome c into the cytosol, and reduced cytochrome c content in mitochondria, addition of bHB blocked this toxic effect. bHB also attenuated the rotenone-induced activation of caspase-9 and caspase-3. Administration of 0-10 mM 3-nitropropionic acid, a complex II inhibitor, also decreased the reducing power of SH-SY5Y cells measured by alamarBlue assay. Pretreatment with 8 mM bHB attenuated the decrease of alamarBlue fluorescence. These data demonstrated that bHB had a neuroprotective effect that supported the mitochondrial respiration system by reversing the inhibition of complex I or II. Ketone bodies, the alternative energy source in the mammalian brain, appear to have therapeutic potential in PD.
authors.affiliation: Department of Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan. imamurakeiko@nifty.com
authors.forename: Keiko
authors.initials: K
authors.lastname: Imamura
authors.forename: Takao
authors.initials: T
authors.lastname: Takeshima
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kashiwaya
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nakaso
authors.forename: Kenji
authors.initials: K
authors.lastname: Nakashima
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000494:pharmacology*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004298:Dopamine / Q000502:physiology*; D005456:Fluorescent Dyes; D006801:Humans; D007211:Indoles; D007657:Ketone Bodies / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000473:pathology*; D009498:Neurotoxins / Q000633:toxicity; D009574:Nitro Compounds / Q000633:toxicity; D010084:Oxidation-Reduction; D010302:Parkinson Disease, Secondary / Q000139:chemically induced* / Q000473:pathology / Q000517:prevention & control*; D011422:Propionates / Q000633:toxicity; D012402:Rotenone / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D013386:Succinates / Q000494:pharmacology; D014475:Uncoupling Agents / Q000037:antagonists & inhibitors* / Q000633:toxicity*
chemical_list: D005456:Fluorescent Dyes; D007211:Indoles; D007657:Ketone Bodies; D009498:Neurotoxins; D009574:Nitro Compounds; D011422:Propionates; D013386:Succinates; D014475:Uncoupling Agents; D012402:Rotenone; C007293:DAPI; D007770:L-Lactate Dehydrogenase; D053148:Caspase 3; D053453:Caspase 9; C015392:3-nitropropionic acid; D020155:3-Hydroxybutyric Acid; D004298:Dopamine