title: Differentiation of human adipose-derived stem cells into fat involves reactive oxygen species and Forkhead box O1 mediated upregulation of antioxidant enzymes.
abstract: Both reactive oxygen species (ROS) and Forkhead box O (FOXO) family transcription factors are involved in the regulation of adipogenic differentiation of preadipocytes and stem cells. While FOXO has a pivotal role in maintaining cellular redox homeostasis, the interactions between ROS and FOXO during adipogenesis are not clear. Here we examined how ROS and FOXO regulate adipogenesis in human adipose-derived stem cells (hASC). The identity of isolated cells was confirmed by their surface marker expression pattern typical for human mesenchymal stem cells (positive for CD29, CD44, CD73, CD90, and CD105, negative for CD45 and CD31). Using a standard adipogenic cocktail consisting of insulin, dexamethasone, indomethacin, and 3-Isobutyl-1-methylanxthine (IDII), adipogenesis was induced in hASC, which was accompanied by ROS generation. Scavenging ROS production with N-acetyl-L-cysteine or EUK-8, a catalytic mimetic of superoxide dismutase (SOD) and catalase, inhibited IDII-induced adipogenesis. We then mimicked IDII-induced oxidative stress through a lentiviral overexpression of Nox4 and an exogenous application of hydrogen peroxide in hASC and both manipulations significantly enhanced adipogenesis without changing the adipogenic differentiation rate. These data suggest that ROS promoted lipid accumulation in hASC undergoing adipogenesis. Antioxidant enzymes, including SOD2, catalase, and glutathione peroxidase were upregulated by IDII during adipogenesis, and these effects were blunted by FOXO1 silencing, which also suppressed significantly IDII-induced adipogenesis. Our findings demonstrated a balance of ROS generation and endogenous antioxidants in cells undergoing adipogenesis. Approaches targeting ROS and/or FOXO1 in adipocytes may bring new strategies to prevent and treat obesity and metabolic syndrome.
authors.affiliation: Centre for Eye Research Australia, East Melbourne, Victoria, Australia.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Higuchi
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Dusting
authors.forename: Hitesh
authors.initials: H
authors.lastname: Peshavariya
authors.forename: Fan
authors.initials: F
authors.lastname: Jiang
authors.forename: Sarah Tzu-Feng
authors.initials: ST
authors.lastname: Hsiao
authors.forename: Elsa C
authors.initials: EC
authors.lastname: Chan
authors.forename: Guei-Sheung
authors.initials: GS
authors.lastname: Liu
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D050156:Adipogenesis; D000273:Adipose Tissue / Q000166:cytology*; D053687:Adult Stem Cells / Q000201:enzymology / Q000502:physiology*; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins; D004790:Enzyme Induction; D000071161:Forkhead Box Protein O1; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D050356:Lipid Metabolism; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress; D034741:RNA, Small Interfering / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation; D000099156:Superoxide Dismutase 2
chemical_list: D015056:1-Methyl-3-isobutylxanthine; D002374:Catalase; D018797:Cell Cycle Proteins; D000071161:Forkhead Box Protein O1; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; D005979:Glutathione Peroxidase; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D014157:Transcription Factors; D000099156:Superoxide Dismutase 2; C085126:FOXO1 protein, human; C499517:FOXO3 protein, human; C108803:FOXO4 protein, human; C498910:NOX4 protein, human