title: Prooxidant properties of p66shc are mediated by mitochondria in human cells.
abstract: p66shc is a protein product of an mRNA isoform of SHC1 gene that has a pro-oxidant and pro-apoptotic activity and is implicated in the aging process. Mitochondria were suggested as a major source of the p66shc-mediated production of reactive oxygen species (ROS), although the underlying mechanisms are poorly understood. We studied effects of p66shc on oxidative stress induced by hydrogen peroxide or by serum deprivation in human colon carcinoma cell line RKO and in diploid human dermal fibroblasts (HDFs). An shRNA-mediated knockdown of p66shc suppressed and an overexpression of a recombinant p66shc stimulated the production of ROS in the both models. This effect was not detected in the mitochondrial DNA-depleted ρ0-RKO cells that do not have the mitochondrial electron transport chain (ETC). The p66shc-dependent accumulation of mitochondrial ROS was detected with HyPer-mito, a mitochondria-targeted fluorescent protein sensor for hydrogen peroxide. The fragmentation of mitochondria induced by mitochondrial ROS was significantly reduced in the p66shc deficient RKO cells. Mitochondria-targeted antioxidants SkQ1 and SkQR1 also decreased the oxidative stress induced by hydrogen peroxide or by serum deprivation. Together the data indicate that the p66shc-dependant ROS production during oxidative stress has mitochondrial origin in human normal and cancer cells.
authors.affiliation: Belozersky Institute of Physical and Chemical Biology, Moscow State University, Moscow, Russia; Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Evgeny R
authors.initials: ER
authors.lastname: Galimov
authors.affiliation: Belozersky Institute of Physical and Chemical Biology, Moscow State University, Moscow, Russia.
authors.forename: Boris V
authors.initials: BV
authors.lastname: Chernyak
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Alena S
authors.initials: AS
authors.lastname: Sidorenko
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Alesya V
authors.initials: AV
authors.lastname: Tereshkova
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia; Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America; Novosibirsk State University, Novosibirsk, Russia.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Chumakov
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D002460:Cell Line; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D017382:Reactive Oxygen Species; D055765:Shc Signaling Adaptor Proteins / Q000235:genetics / Q000378:metabolism*; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; C528024:SHC1 protein, human; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D006861:Hydrogen Peroxide