title: Selenium supplementation restores the antioxidative capacity and prevents cell damage in bone marrow stromal cells in vitro.
abstract: Bone marrow stromal cells (BMSCs) and other cell populations derived from mesenchymal precursors are developed for cell-based therapeutic strategies and undergo cellular stress during ex vivo procedures. Reactive oxygen species (ROS) of cellular and environmental origin are involved in redox signaling, cumulative cell damage, senescence, and tumor development. Selenium-dependent (glutathione peroxidases [GPxs] and thioredoxin reductases [TrxRs]) and selenium-independent (superoxide dismutases [SODs] and catalase [CAT]) enzyme systems regulate cellular ROS steady state levels. SODs process superoxide anion to hydrogen peroxide, which is subsequently neutralized by GPx and CAT; TrxR neutralizes other ROS, such as peroxinitrite. Primary BMSCs and telomerase-immortalized human mesenchymal stem cells (hMSC-TERT) express GPx1-3, TrxR1, TrxR2, SOD1, SOD2, and CAT. We show here that in standard cell cultures (5%-10% fetal calf serum, 5-10 nM selenite), the activity of antioxidative selenoenzymes is impaired in hMSC-TERT and BMSCs. Under these conditions, the superoxide anion processing enzyme SOD1 is not sufficiently stimulated by an ROS load. Resulting oxidative stress favors generation of micronuclei in BMSCs. Supplementation of selenite (100 nM) restores basal GPx and TrxR activity, rescues basal and ROS-stimulated SOD1 mRNA expression and activity, and reduces ROS accumulation in hMSC-TERT and micronuclei generation in BMSCs. In conclusion, BMSCs in routine cell culture have low antioxidative capacity and are subjected to oxidative stress, as indicated by the generation of micronuclei. Selenite supplementation of BMSC cultures appears to be an important countermeasure to restore their antioxidative capacity and to reduce cell damage in the context of tissue engineering and transplantation procedures.
authors.affiliation: Musculosceletal Research Center, Orthopaedic Department, University of Würzburg, Brettreichstrasse 11, D-97074 Würzburg, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Ebert
authors.forename: Matthias
authors.initials: M
authors.lastname: Ulmer
authors.forename: Sabine
authors.initials: S
authors.lastname: Zeck
authors.forename: Jutta
authors.initials: J
authors.lastname: Meissner-Weigl
authors.forename: Doris
authors.initials: D
authors.lastname: Schneider
authors.forename: Helga
authors.initials: H
authors.lastname: Stopper
authors.forename: Nicole
authors.initials: N
authors.lastname: Schupp
authors.forename: Moustapha
authors.initials: M
authors.lastname: Kassem
authors.forename: Franz
authors.initials: F
authors.lastname: Jakob
mesh_terms: D001483:Base Sequence; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000201:enzymology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry; D004249:DNA Damage; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000201:enzymology; D015162:Micronucleus Tests; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012313:RNA; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012643:Selenium / Q000494:pharmacology*; D017154:Stromal Cells / Q000187:drug effects* / Q000201:enzymology
chemical_list: D003470:Culture Media; D017382:Reactive Oxygen Species; D012313:RNA; D010088:Oxidoreductases; D012643:Selenium