title: Uncoupling protein-2 is critical for nigral dopamine cell survival in a mouse model of Parkinson's disease.
abstract: Mitochondrial uncoupling proteins dissociate ATP synthesis from oxygen consumption in mitochondria and suppress free-radical production. We show that genetic manipulation of uncoupling protein-2 (UCP2) directly affects substantia nigra dopamine cell function. Overexpression of UCP2 increases mitochondrial uncoupling, whereas deletion of UCP2 reduces uncoupling in the substantia nigra-ventral tegmental area. Overexpression of UCP2 decreased reactive oxygen species (ROS) production, which was measured using dihydroethidium because it is specifically oxidized to fluorescent ethidium by the superoxide anion, whereas mice lacking UCP2 exhibited increased ROS relative to wild-type controls. Unbiased electron microscopic analysis revealed that the elevation of in situ mitochondrial ROS production in UCP2 knock-out mice was inversely correlated with mitochondria number in dopamine neurons. Lack of UCP2 increased the sensitivity of dopamine neurons to 1-methyl-4-phenyl-1,2,5,6 tetrahydropyridine (MPTP), whereas UCP2 overexpression decreased MPTP-induced nigral dopamine cell loss. The present results expose the critical importance of UCP2 in normal nigral dopamine cell metabolism and offer a novel therapeutic target, UCP2, for the prevention/treatment of Parkinson's disease.
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
authors.forename: Zane B
authors.initials: ZB
authors.lastname: Andrews
authors.forename: Balazs
authors.initials: B
authors.lastname: Horvath
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Barnstable
authors.forename: John
authors.initials: J
authors.lastname: Elsworth
authors.forename: John
authors.initials: J
authors.lastname: Elseworth
authors.forename: Lichuan
authors.initials: L
authors.lastname: Yang
authors.forename: M Flynt
authors.initials: MF
authors.lastname: Beal
authors.forename: Robert H
authors.initials: RH
authors.lastname: Roth
authors.forename: Russell T
authors.initials: RT
authors.lastname: Matthews
authors.forename: Tamas L
authors.initials: TL
authors.lastname: Horvath
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology; D015655:1-Methyl-4-phenylpyridinium / Q000378:metabolism; D000818:Animals; D002470:Cell Survival / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D007473:Ion Channels; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008928:Mitochondria / Q000473:pathology / Q000502:physiology; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D020734:Parkinsonian Disorders / Q000378:metabolism* / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D000071246:Uncoupling Protein 2
chemical_list: D007473:Ion Channels; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; C000604389:UCP2 protein, human; C000604390:Ucp2 protein, mouse; D000071246:Uncoupling Protein 2; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D015655:1-Methyl-4-phenylpyridinium; D004298:Dopamine