title: SET overexpression in HEK293 cells regulates mitochondrial uncoupling proteins levels within a mitochondrial fission/reduced autophagic flux scenario.
abstract: We hypothesized that SET, a protein accumulated in some cancer types and Alzheimer disease, is involved in cell death through mitochondrial mechanisms. We addressed the mRNA and protein levels of the mitochondrial uncoupling proteins UCP1, UCP2 and UCP3 (S and L isoforms) by quantitative real-time PCR and immunofluorescence as well as other mitochondrial involvements, in HEK293 cells overexpressing the SET protein (HEK293/SET), either in the presence or absence of oxidative stress induced by the pro-oxidant t-butyl hydroperoxide (t-BHP). SET overexpression in HEK293 cells decreased UCP1 and increased UCP2 and UCP3 (S/L) mRNA and protein levels, whilst also preventing lipid peroxidation and decreasing the content of cellular ATP. SET overexpression also (i) decreased the area of mitochondria and increased the number of organelles and lysosomes, (ii) increased mitochondrial fission, as demonstrated by increased FIS1 mRNA and FIS-1 protein levels, an apparent accumulation of DRP-1 protein, and an increase in the VDAC protein level, and (iii) reduced autophagic flux, as demonstrated by a decrease in LC3B lipidation (LC3B-II) in the presence of chloroquine. Therefore, SET overexpression in HEK293 cells promotes mitochondrial fission and reduces autophagic flux in apparent association with up-regulation of UCP2 and UCP3; this implies a potential involvement in cellular processes that are deregulated such as in Alzheimer's disease and cancer.
authors: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors: Luciana O
authors: LO
authors: Almeida
authors: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors: Renata N
authors: RN
authors: Goto
authors: Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors: Marinaldo P C
authors: MP
authors: Neto
authors: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors: Lucas O
authors: LO
authors: Sousa
authors: Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors: Carlos
authors: C
authors: Curti
authors: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil. Electronic address: andreiaml@usp.br.
authors: Andréia M
authors: AM
authors: Leopoldino
mesh_terms: D001343:Autophagy / Q000502:physiology*; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation / Q000502:physiology*; D057809:HEK293 Cells; D056488:Histone Chaperones / Q000378:metabolism*; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D008928:Mitochondria / Q000502:physiology*; D063154:Mitochondrial Dynamics / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology; D014157:Transcription Factors / Q000378:metabolism*; D000071256:Uncoupling Protein 1; D015854:Up-Regulation / Q000502:physiology
chemical_list: D004268:DNA-Binding Proteins; D056488:Histone Chaperones; D007473:Ion Channels; D024101:Mitochondrial Proteins; C513473:SET protein, human; D014157:Transcription Factors; C000604371:UCP1 protein, human; D000071256:Uncoupling Protein 1
keywords: Mitochondria; Mitochondrial fission; SET; UCPs