title: Brain mitochondria from DJ-1 knockout mice show increased respiration-dependent hydrogen peroxide consumption.
abstract: Mutations in the DJ-1 gene have been shown to cause a rare autosomal-recessive genetic form of Parkinson's disease (PD). The function of DJ-1 and its role in PD development has been linked to multiple pathways, however its exact role in the development of PD has remained elusive. It is thought that DJ-1 may play a role in regulating reactive oxygen species (ROS) formation and overall oxidative stress in cells through directly scavenging ROS itself, or through the regulation of ROS scavenging systems such as glutathione (GSH) or thioredoxin (Trx) or ROS producing complexes such as complex I of the electron transport chain. Previous work in this laboratory has demonstrated that isolated brain mitochondria consume H2O2 predominantly by the Trx/Thioredoxin Reductase (TrxR)/Peroxiredoxin (Prx) system in a respiration dependent manner (Drechsel et al., Journal of Biological Chemistry, 2010). Therefore we wanted to determine if mitochondrial H2O2 consumption was altered in brains from DJ-1 deficient mice (DJ-1(-/-)). Surprisingly, DJ-1(-/-) mice showed an increase in mitochondrial respiration-dependent H2O2 consumption compared to controls. To determine the basis of the increased H2O2 consumption in DJ1(-/-) mice, the activities of Trx, Thioredoxin Reductase (TrxR), GSH, glutathione disulfide (GSSG) and glutathione reductase (GR) were measured. Compared to control mice, brains from DJ-1(-/-) mice showed an increase in (1) mitochondrial Trx activity, (2) GSH and GSSG levels and (3) mitochondrial glutaredoxin (GRX) activity. Brains from DJ-1(-/-) mice showed a decrease in mitochondrial GR activity compared to controls. The increase in the enzymatic activities of mitochondrial Trx and total GSH levels may account for the increased H2O2 consumption observed in the brain mitochondria in DJ-1(-/-) mice perhaps as an adaptive response to chronic DJ-1 deficiency.
authors.affiliation: Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States of America.
authors.forename: Pamela
authors.initials: P
authors.lastname: Lopert
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, 12850 E. Montview Blvd, Aurora, CO 80045, United States of America.
authors.forename: Manisha
authors.initials: M
authors.lastname: Patel
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D054477:Glutaredoxins / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008928:Mitochondria / Q000378:metabolism*; D015513:Oncogene Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D054464:Peroxiredoxins / Q000378:metabolism; D000071617:Protein Deglycase DJ-1; D013880:Thioredoxin-Disulfide Reductase / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism
chemical_list: D054477:Glutaredoxins; D015513:Oncogene Proteins; D013879:Thioredoxins; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D013880:Thioredoxin-Disulfide Reductase; C503466:PARK7 protein, mouse; D000071617:Protein Deglycase DJ-1; D005978:Glutathione
keywords: 4-HNE, 4-hydroxyl-2-nonenal; 6OHDA, 6-hydroxydopamine; ASK1, apoptosis signal-regulating kinase 1; BSA, Bovin Serum Albumin; Cox IV, complex IV; DA, dopaminergic; DJ-1; DJ1-/-, DJ-1 knockout; GR, glutathione reductase; GRX, glutaredoxin; GSH, reduced glutathione; GSSG, oxidized glutathione; Gpx, glutathione peroxidase; H2O2, hydrogen peroxide; HEDS, 2-hydroxyethyl disulfide; MEF, mouse embryonic fibroblasts; MPTP, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Mitochondria; Nrf2, nuclear factor erythroid 2-related factor; Oxidative stress; PD, Parkinson’s disease; PQ, paraquat; Parkinson’s disease; Prx, peroxiredoxin; ROS, reactive oxygen species; SNpc, substantia nigra pars compacta; TH, tyrosine hydroxylase; Thioredoxin; Thioredoxin reductase; Trx, thioredoxin; Trx1, cytosolic trx; Trx2, mitochondrial trx; TrxR, thioredoxin reductase; TrxR1, cytosolic TrxR; TrxR2, mitochondrial Trx