title: Oxidative stress and alterations in actin cytoskeleton trigger glutathione efflux in Saccharomyces cerevisiae.
abstract: A marked deficiency in glutathione (GSH), the most abundant antioxidant in living systems, plays a major role in aging and the pathogenesis of diseases ranging from neurological disorders to early atherosclerosis and the impairment of various immunological functions. In an attempt to shed light on GSH homeostasis, we carried out the space experiment SCORE (Saccharomyces cerevisiae oxidative stress response evaluation) during the FOTON-M3 mission. Microgravity and hyperoxic conditions induced an enormous extracellular release of GSH from S. cerevisiae cells (≈40% w/dw), changed the distribution of the buds, and activated the high osmolarity glycerol (HOG) and cell integrity/PKC pathways, as well as protein carbonylation. The results from the single spaceflight experiment were validated by a complete set of experiments under conditions of simulated microgravity and indicate that cytoskeletal alterations are mainly responsible for the observed effects. The results of ground experiments in which we induced cytoskeletal modifications by means of treatment with dihydrocytochalasin B (DHCB), a potent inhibitor of actin polymerisation, or (R)-(+)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide dihydrochloride monohydrate (Y-27632), a selective ROCK (Rho-associated coiled-coil forming protein serine/threonine kinase) inhibitor, confirmed the role of actin in GSH efflux. We also found that the GSH release can be inhibited using the potent chloride channel blocker 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB).
authors: CNR-ISTM Institute of Molecular Science and Technologies, National Council of Research, via Golgi 19, 20133 Milan, Italy. silvia.bradamante@istm.cnr.it
authors: Silvia
authors: S
authors: Bradamante
authors: Alessandro
authors: A
authors: Villa
authors: Silvia
authors: S
authors: Versari
authors: Livia
authors: L
authors: Barenghi
authors: Ivan
authors: I
authors: Orlandi
authors: Marina
authors: M
authors: Vai
mesh_terms: D000199:Actins / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D018384:Oxidative Stress; D012441:Saccharomyces cerevisiae / Q000378:metabolism*
chemical_list: D000199:Actins; D005978:Glutathione