dye mitoSOX and complex I inhibitor rotenone, we identified the mitochondrial respiratory chain as the major PGC-1α dependent ROS source in vivo. In accordance with the prominent role of mitochondrial ROS for the signalling events leading to vascular aging and apoptosis, we found increased expression of p16INK4 and Chk-2 as markers of cell senescence as well as increased TUNEL-staining accompanied by activation of the JNK pathway in aortas from ATII treated PGC-1α knockout mice. Conclusions: PGC-1α deficiency impairs endothelial function during chronic angiotensin II infusion by increasing mitochondrial ROS production, resulting in premature vascular aging and apoptosis.

20 Platelet Activation during Storage Depends on Oxidative Damage and Fibrinolytic Factors Activation Jaime González-Cuevas1, Jesús Javier García-Bañuelos1, José Navarro-Partida1, and Juan Armendáriz-Borunda1 1Universidad de Guadalajara, Mexico Background: Platelet rich plasma is used in multiple coagulation disorders. Its therapeutic effectiveness is related to technical procedures for procurement, storage conditions and aging. Because free radicals induce platelet activation and aging, this work is focused on elucidating the oxidative mechanism for platelets activation during storage. Methods: Platelet rich plasmas were obtained from 110 healthy donors from a transfusable medical service and kept under stirring at temperature of 20-24˚C. Protein extraction was performed from platelets homogenates and plasma at different times of storage from day 1 to day 20. Activity of the antioxidants molecules catalase, superoxide dismutase and ceruloplasmin, as well as the activity of the fibrinolytic proteins metalloproteases 2, 9 and 3 (MMP-2, MMP-9 and MMP-3), plasmin and urokinase plasminogen activator (uPA) were analyzed by zymography assays. Additionally, we also determined the amount of oxidized proteins (Oxiblot). Results: We observed significant activity of antioxidant and fibrinolytic molecules on the 5th day of storage in platelets homogenates, which was increased trough the time and correlated concomitantly with levels of oxidized proteins. A reverse pattern of activity was observed in plasma, except for catalase, which remained unchanged. Conclusion: Storage conditions of platelet rich plasma after the 5th day allow platelets activation ex vivo by oxidative damage and proteolysis, with the consequent therapeutic efficiency decrement.

21 Oxidative Stress Markers in Children with Autism Spectrum Disorders Maria Elena Gonzalez-Fraguela1, Mei-Li Diaz Hung1, Hector Vera1, Maria Robinson1, and Carmem Gottfried2 1International Center for Neurological Restoration, Cuba 2Universidades do Rio Grande do Sur, Brazil Background: The cause of autism remains elusive, this medical condition is considered a multifactorial disorder that is influenced by genetic and environmental factors as well as increased vulnerability to oxidative stress. The understanding of the potential role of oxidative stress in the etiopathogenesis of autism

would be very useful for earlier clinical, therapeutic or preventive strategies. Methods: Peripheral blood samples of 30 children with autism and 20 age-matching control children were evaluated for the activity of the antioxidant enzyme catalase (CAT), glutathione concentration (GSH) and markers of damage to biomolecules, malonyldialdehyde (MDA) and 8–hydroxy-2-deoxyguanosine (8OHdG), using spectrophotometric methods and ELISA kit assay. Results: The autistic group showed several statistically significant differences in their oxidative stress indicators compared to the control group, for both biomarkers of damage to biomolecules and antioxidant defenses. The reduced GSH content in autistic patients was significantly lower compared with the control group (0.57 ± 0.162 vs. 0.94 ± 0.115, respectively, p 0.001). Higher serum CAT, MDA and 8OHdG levels were found in children with autism compared with controls (CAT, 2.836 ± 0.479 vs. 0.689 ± 0.157, p 0.001; MDA 8.6 ± 0.5 vs. 1.76 ± 0.33 p 0.001, and 8OHdG 13.134 ± 1.33 vs.1.46 ± 0.326, p 0.001). Conclusion: The present study supports the notion that oxidative stress is associated with autism. Additional researches are needed to investigate if the oxidant/antioxidant equilibrium is a key piece in the etiopathogenesis of autism.

22 Superoxide Generation by Selenium Compounds and a Putative Observance of a Free Radical Chain Reaction Debalina Goswami1, Mallory Boylan1, and Julian Ernest Spallholz1 1Texas Tech University Selenodiglutathione (GSSeSG) is formed from the reaction between selenite (SeO3

2 ) and glutathione (GSH) in vitro and in biological systems. Several comparative cell culture studies have shown that selenodiglutathione is more toxic to cells having a lower LD50 than other selenium (Se) compounds. In this study five different Se compounds were compared using Lucigenin chemiluminescence (CL) for quantitating the generation of superoxide from selenium catalyzed GSH oxidation. Total superoxide generation over time in decreasing order by Se concentration was as follows; GSSeSG, SeO32 , methylseleninic acid; MeSeA, diselenodiproprionic acid; DISeDIP and, selenomethionine; SeMet. Quantization of superoxide generation demonstrates the disparity in the catalytic behavior between selenium compounds and correlates closely with known selenium compound cell and animal toxicity. Superoxide dismutase (SOD), ascorbic acid and proteins act as antioxidants in the Lucigenin CL assay. SOD and ascorbic acid quench CL in an increasing dose dependent manner. Increasing protein concentrations in this CL assay may either increase or decrease CL. When selenium generated CL is increased in the presence of proteins a putative free radical chain reaction is believed to have occurred. These experimental results suggest our observation of a free radical chain reaction involving selenium catalyzed “toxicity” generating protein oxidation. The practical application of this redox technology permits selenium attachment to small molecules, peptides and antibodies for the formation and experimental application of new pharmaceuticals as will be shown for Selenofolate and Herceptin Se conjugates that are potential therapeutic treatments for ovarian and breast cancers that over express folate or HER/2 receptors.

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