even among fairly closely related species.

doi:10.1016/j.freeradbiomed.2011.10.378 255 Oxidatively Truncated Phospholipids Are Required Effectors of Cytokine-Induced Apoptosis Thomas McIntyre1, and Calivarathan Latchoumycandane1 1Cleveland Clinic The oxidized phospholipid azelaoyl phosphatidylcholine (Az-PC), which circulates in chronic inflammation, readily enters cells to initiate intrinsic apoptosis. Here we determined whether this oxidized phospholipid is generated within cells during cytokine stimulation, and whether it appears in sufficient quantities to induce cell death. We find TNFa peroxidized membrane phospholipid with oxidative truncation to Az-PC through superoxide generated by stimulated NADPH oxidase. Nox4 knockdown or NADPH oxidase inhibitors both abolished Az-PC formation, and prevented TNFa-induced cell death. Phospholipid hydroperoxides were essential intermediates in TNFa-induced apoptosis because over expression of glutathione peroxidase 4, which chemically reduces esterified lipid hydroperoxides, blocked Az-PC production and TNFa-induced apoptosis, while its knockdown enhanced oxidized phospholipid accumulation and death. Over-expression of the specific hydrolase for oxidized phospholipids, PAF acetylhydrolase, reduced cytokine-stimulated Az-PC, and it abolished TNFa- and Fas Ligand-induced apoptosis. We conclude oxidatively truncated phospholipids like Az-PC are required components of cytokine-induced apoptosis. Oxidatively truncated phospholipids are previously unknown mobile components of TNFa signaling connecting TNF receptors to mitochondrial dysfunction and death.

doi:10.1016/j.freeradbiomed.2011.10.379 256 Pioglitazone Improves Mouse Survival After Post-Burn Bacterial Infection Via Restoration of Kupffer Cell Function Hiromi Miyazaki1, Manabu Kinoshita1, Satoshi Ono1, Shuhji Seki1, and Daizoh Saitoh1 1National Defense Medical College, Japan Macrophages engage in phagocytosis and rapidly release reactive oxygen species, which exert an important microbicidal function. Burn injury causes the Kupffer cell dysfunction and attenuates the host defense. the nuclear receptor peroxisome proliferator activated receptor-γ (PPAR-γ) is widely expressed in macrophages and plays an important role for regulation of immune responses. Pioglitazone (PIO), a PPAR-γ agonist, has been reported to be an anti-inflammatory agent. We investigated the effects of PIO in mouse post-burn E. coli infection. C57BL/6 mice received a full-thickness burn injury. Five days after injury, they were administered with PIO or vehicle, followed by E. coli challenge. Burn injury decreased the phagocytic activity by Kupffer cells and impaired bacterial clearance in the mouse liver after infection. PIO pretreatment augmented the phagocytic activity by Kupffer cells and restored bacterial clearance, thereby improving mouse survival after post-burn infection. Although burn injury increased TNF-α levels after infection as compared to those in sham mice, PIO pretreatment suppressed TNF-α levels. It is concluded that PIO treatment may modulate inflammatory responses to post-burn infection via suppressing proinflammatory

cytokine production and enhancing phagocytic function of Kupffer cells/macrophages.

doi:10.1016/j.freeradbiomed.2011.10.380 257 Chemiluminescence of the Whole Human Blood Phagocytes: a New Method of Measurement Igor V. Obraztsov1 1Chair for Medical Biophysics, Faculty for Fundamental Medicine, Lomonosov Moscow State University Our research aims to argue that chemiluminescent (CL) analysis is one of the most convenient and effective methods to evaluate leukocyte activation in patients with various diseases. Mononuclear phagocytes and neutrophils as a part of nonspecific immunity factors play a crucial role in antimicrobial resistance. Reactive oxygen species (ROS) including free radicals are important compound of the phagocytes’ microbicidal action. Our previous literature review has shown that analysis of phagocytic ROS production could provide valuable data on a phagocyte link of immunity. CL assay being highly sensitive does not affect biochemical processes and allows evaluating oxidative output of the cells in dynamics. Comparing of how different stimuli affect the whole blood phagocytes under various conditions provides a deeper insight into oxidative metabolism pathways. Our experiments enable to obtain curves of luminol-dependent spontaneous CL and CL response of whole blood phagocytes in healthy donors under conditions of various corpuscular and soluble stimuli – Latex, 4-phorbol-12-myristate-13-acetate (PMA), N-formyl-methionyl-leucyl-phenylalanine (FMLP) and their combinations. Our findings have shown optima for their concentrations and for time interval between blood sampling and CL measurement (the optimum means the highest amplitude of CL response). We have also analysed a blood dilution impact to CL response. As a result we suggest reliable and replicable method on the evaluation of a phagocyte function applicable in clinical practice. the suggested method is based on a step-by-step stimulation of the cells by PMA and FMLP. Using this method, we argue, one might foresee future tendencies on septic complications.

doi:10.1016/j.freeradbiomed.2011.10.381

258 Acrolein, a Major Component of Tobacco Smoke, Suppresses Allergic Airway Inflammation in Sensitized Mice in Vivo Page C. Spiess1, Milena Hristova1, Matthew J. Randall1, and Albert van der Vliet1 1University of Vermont The adverse health effects of tobacco smoke arise partly from its influence on innate and adaptive immune responses, leading to impaired innate immunity and host defense. the effects of smoking on allergic asthma are less clear, however, with various reports demonstrating that cigarette smoking may enhance asthma development but can also suppress allergic airway inflammation. Based on our previous findings that immunosuppressive effects of smoking may be largely attributed to one of its main reactive electrophiles, acrolein (ACR), we explored the impact of ACR exposure in a mouse model of allergic asthma. Using the ovalbumin (OVA) model of asthma, exposure of OVA-sensitized mice to ACR (5 ppm, 6 hrs/day, 4 days) immediately following OVA challenge was found to dramatically suppress allergic airway inflammation, demonstrated

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