title: Proteomic analysis reveals higher demand for antioxidant protection in embryonic stem cell-derived smooth muscle cells.
abstract: Embryonic stem (ES) cells can differentiate into vascular smooth muscle cells (SMCs), but differences in protein composition, function and behaviour between stem cell-derived and mature SMCs remain to be characterized. Using differential in gel electrophoresis (DIGE) and MS, we identified 146 proteins that differed between ES cell-derived SMCs (esSMCs) and aortic SMCs, including proteins involved in DNA maintenance (higher in esSMCs), cytoskeletal proteins and calcium-binding proteins (higher in aortic SMCs). Notably, esSMCs showed decreased expression of mitochondrial, but a compensatory increase of cytosolic antioxidants. Subsequent experiments revealed that mitochondrial-derived reactive oxygen species (ROS) were markedly increased in esSMCs. Despite a three-fold rise in glutathione (GSH) reductase activity, esSMCs had lower levels of reduced GSH, and depletion of GSH by diethyl maleate or inhibition of GSH reductase by carmustine (BCNU) resulted in more pronounced cell death compared to aortic SMCs, while addition of antioxidants improved the viability of esSMCs. We present the first proteomic analysis of esSMCs demonstrating that stem cell-derived SMCs are more sensitive to oxidative stress due to increased generation of mitochondrial-derived ROS and require additional antioxidant protection for survival.
authors.affiliation: Cardiovascular Division, School of Medicine, King's College, University of London, UK.
authors.forename: Xiaoke
authors.initials: X
authors.lastname: Yin
authors.forename: Manuel
authors.initials: M
authors.lastname: Mayr
authors.forename: Qingzhong
authors.initials: Q
authors.lastname: Xiao
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
authors.forename: Qingbo
authors.initials: Q
authors.lastname: Xu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001483:Base Sequence; D002460:Cell Line; D002470:Cell Survival; D002478:Cells, Cultured; D017931:DNA Primers / Q000235:genetics; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D004734:Energy Metabolism; D051379:Mice; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000378:metabolism*; D018384:Oxidative Stress; D040901:Proteomics / Q000379:methods*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D017931:DNA Primers; D009124:Muscle Proteins; D017382:Reactive Oxygen Species