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Cellular redox status mediates adaptive response to ionizing radiation in human peripheral blood mononuclear cells
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D. Rossin et al. / Free Radical Biology and Medicine 108 (2017) S18–S107
P-014
Rapid ascorbate response to bacterial elicitor treatment in Arabidopsis thaliana cells András Szarka, Péter Hajdinák, Ádám Czobor Budapest University of Technology and Economics, Hungary Keywords: Oxidative burst; ROS; harpin proteins; ascorbate; glutathione; hypersensitive response; plant-pathogen interaction
An early event of the incompatible plant-pathogen interactions is an oxidative burst. The major water soluble, low molecular weight antioxidant, ascorbic acid plays a crucial role in Reactive Oxygen Species (ROS) balancing (scavenging). The regulation of ascorbate level therefore can be an important point of the fine tuning of ROS level during the early phase of plant-pathogen interaction. To evaluate how this interaction affects the biosynthesis, the recycling and the level of ascorbate, we challenged Arabidopsis thaliana cells with 2 different harpin proteins (HrpZpto and HrpWpto). HrpZpto and HrpWpto treatments caused a well-defined ROS peak. The expression of the alternative oxidase (AOX1a) and vtc5, one of the paralog genes that encode the rate limiting enzyme of ascorbate biosynthesis followed the elevation of ROS. Similarly the activity of ascorbate-peroxidase and galactono-1,4-lactone dehydrogenase (GLDH), the enzyme catalyzing the ultimate, mitochondria coupled step of ascorbate biosynthesis and the level of ascorbate and glutathione also followed the elevation of ROS due to harpin treatment. The enhanced expression of AOX1a, the elevated activity of GLDH and the increased level of ascorbate and glutathione all can contribute to the mitigation or absence of programmed cell death. Finally a new function, the fine tuning of redox balance during plant-pathogen interaction can be proposed to vtc5. E-mail address: [email protected] (A. Szarka) http://dx.doi.org/10.1016/j.freeradbiomed.2017.04.099
and γH2AX, was used as the endpoint to demonstrate adaptive response in PBMCs exposed to a priming dose of 10 cGy Co60 γrays followed by a challenge dose of 2 Gy γ-rays (dose rate 0.3 Gy/ min) after 4 hours. Primed cells showed significantly lesser DNA damage accompanied with decreased levels of ROS and increased antioxidant responses. This included changes in the expression for genes like SOD2, GPx, CAT and TRX. In addition, increased activity of enzymatic defense system, mainly SOD and TXNRD, but not CAT and GPx, was observed in the primed cells. These responses were shown to be mediated through increased DNA binding of stress responsive transcription factors Nrf2 and NFκB. The primed cells also showed early activation of ERK, p38 and JNK MAP kinases. Label-free LCMS analysis revealed unique pattern of differentially expressed proteins in the primed cells. A better understanding of adaptive response will contribute towards refinement of radiation protection strategies and radiotherapy protocols. E-mail address: [email protected] (N. Paraswani) Acknowledgements
Funding was provided by Council of Scientific & Industrial Research (CSIR), New Delhi, India. http://dx.doi.org/10.1016/j.freeradbiomed.2017.04.100
P-016
Cytoprotective effects of Chilean wild currants (Ribes spp.) against oxidative stress mediated by enhancing the activity of cellular antioxidant enzymes Felipe Jiménez-Aspee 1, Cristina Theoduloz 2, Guillermo Schmeda-Hirschmann 3 1
Nucleo Científico Multidisciplinario, Dirección de Investigación, Universidad de Talca, Chile 2 Laboratorio de Cultivo Celular, Facultad de Ciencias de la Salud, Universidad de Talca 3 Laboratorio de Productos Naturales, Instituto de Química de Recursos Naturales, Universidad de Talca, Chile
P-015
Cellular redox status mediates adaptive response to ionizing radiation in human peripheral blood mononuclear cells Neha Paraswani 1,2, Anu Ghosh 1,2, Maikho Thoh 3 1
Radiation Signaling Group, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai-400085, India 2 Homi Bhabha National Institute, Anushakti Nagar-400094, India 3 Free Radical Biology Section, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai-400085, India Keywords: Ionizing radiation; Human PBMC; Radioadaptive response; DNA damage; Oxidative stress
Radioadaptive response refers to the phenomenon where a small priming dose of ionizing radiation (IR) reduces the detrimental effects of subsequent higher IR dose. In this study, we demonstrated that adaptive response in human peripheral blood mononuclear cells (PBMCs) is associated with altered cellular oxidative stress. DNA strand breaks, analysed with comet assay
Keywords: Ribes; Cytoprotection; Oxidative Stress; AGS cells; Phenolics
The South American Ribes species are very appreciated for their sweet taste. Continuing our research on Ribes species, we decided to investigate the cytoprotective activity of this fruits against oxidative stress. Phenolic-enriched extracts (PEE), the anthocyanin fraction (AF) and copigments fraction (CF) were prepared in the lab. The cytoprotective effect of the Ribes was evaluated using human gastric epithelial cells (AGS). Cells were incubated overnight with the PEE, AF or CF at different concentrations. Then, AGS cells were exposed to H2O2 for 2 hour and viability was measured by means of the MTT reduction assay. In another experimental approach, cells were scrapped, collected by centrifugation and lysed to determine the activity of intracellular antioxidant enzymes. A significant cytoprotective effect was observed in a dosedependent manner for all species studied. The highest activity was found for R. punctatum with 55.0 7 1.8% of cell viability against 33.0 7 0.4% of survival of untreated cells. No significant difference between PEE, AF or CF in the cytoprotective effect. A significant increase in the activity of superoxide dismutase by all Ribes species was found in a dose dependent manner. Our results on the protective potential of South American Ribes species provides
D. Rossin et al. / Free Radical Biology and Medicine 108 (2017) S18–S107
P-014
Rapid ascorbate response to bacterial elicitor treatment in Arabidopsis thaliana cells András Szarka, Péter Hajdinák, Ádám Czobor Budapest University of Technology and Economics, Hungary Keywords: Oxidative burst; ROS; harpin proteins; ascorbate; glutathione; hypersensitive response; plant-pathogen interaction
An early event of the incompatible plant-pathogen interactions is an oxidative burst. The major water soluble, low molecular weight antioxidant, ascorbic acid plays a crucial role in Reactive Oxygen Species (ROS) balancing (scavenging). The regulation of ascorbate level therefore can be an important point of the fine tuning of ROS level during the early phase of plant-pathogen interaction. To evaluate how this interaction affects the biosynthesis, the recycling and the level of ascorbate, we challenged Arabidopsis thaliana cells with 2 different harpin proteins (HrpZpto and HrpWpto). HrpZpto and HrpWpto treatments caused a well-defined ROS peak. The expression of the alternative oxidase (AOX1a) and vtc5, one of the paralog genes that encode the rate limiting enzyme of ascorbate biosynthesis followed the elevation of ROS. Similarly the activity of ascorbate-peroxidase and galactono-1,4-lactone dehydrogenase (GLDH), the enzyme catalyzing the ultimate, mitochondria coupled step of ascorbate biosynthesis and the level of ascorbate and glutathione also followed the elevation of ROS due to harpin treatment. The enhanced expression of AOX1a, the elevated activity of GLDH and the increased level of ascorbate and glutathione all can contribute to the mitigation or absence of programmed cell death. Finally a new function, the fine tuning of redox balance during plant-pathogen interaction can be proposed to vtc5. E-mail address: [email protected] (A. Szarka) http://dx.doi.org/10.1016/j.freeradbiomed.2017.04.099
and γH2AX, was used as the endpoint to demonstrate adaptive response in PBMCs exposed to a priming dose of 10 cGy Co60 γrays followed by a challenge dose of 2 Gy γ-rays (dose rate 0.3 Gy/ min) after 4 hours. Primed cells showed significantly lesser DNA damage accompanied with decreased levels of ROS and increased antioxidant responses. This included changes in the expression for genes like SOD2, GPx, CAT and TRX. In addition, increased activity of enzymatic defense system, mainly SOD and TXNRD, but not CAT and GPx, was observed in the primed cells. These responses were shown to be mediated through increased DNA binding of stress responsive transcription factors Nrf2 and NFκB. The primed cells also showed early activation of ERK, p38 and JNK MAP kinases. Label-free LCMS analysis revealed unique pattern of differentially expressed proteins in the primed cells. A better understanding of adaptive response will contribute towards refinement of radiation protection strategies and radiotherapy protocols. E-mail address: [email protected] (N. Paraswani) Acknowledgements
Funding was provided by Council of Scientific & Industrial Research (CSIR), New Delhi, India. http://dx.doi.org/10.1016/j.freeradbiomed.2017.04.100
P-016
Cytoprotective effects of Chilean wild currants (Ribes spp.) against oxidative stress mediated by enhancing the activity of cellular antioxidant enzymes Felipe Jiménez-Aspee 1, Cristina Theoduloz 2, Guillermo Schmeda-Hirschmann 3 1
Nucleo Científico Multidisciplinario, Dirección de Investigación, Universidad de Talca, Chile 2 Laboratorio de Cultivo Celular, Facultad de Ciencias de la Salud, Universidad de Talca 3 Laboratorio de Productos Naturales, Instituto de Química de Recursos Naturales, Universidad de Talca, Chile
P-015
Cellular redox status mediates adaptive response to ionizing radiation in human peripheral blood mononuclear cells Neha Paraswani 1,2, Anu Ghosh 1,2, Maikho Thoh 3 1
Radiation Signaling Group, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai-400085, India 2 Homi Bhabha National Institute, Anushakti Nagar-400094, India 3 Free Radical Biology Section, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai-400085, India Keywords: Ionizing radiation; Human PBMC; Radioadaptive response; DNA damage; Oxidative stress
Radioadaptive response refers to the phenomenon where a small priming dose of ionizing radiation (IR) reduces the detrimental effects of subsequent higher IR dose. In this study, we demonstrated that adaptive response in human peripheral blood mononuclear cells (PBMCs) is associated with altered cellular oxidative stress. DNA strand breaks, analysed with comet assay
Keywords: Ribes; Cytoprotection; Oxidative Stress; AGS cells; Phenolics
The South American Ribes species are very appreciated for their sweet taste. Continuing our research on Ribes species, we decided to investigate the cytoprotective activity of this fruits against oxidative stress. Phenolic-enriched extracts (PEE), the anthocyanin fraction (AF) and copigments fraction (CF) were prepared in the lab. The cytoprotective effect of the Ribes was evaluated using human gastric epithelial cells (AGS). Cells were incubated overnight with the PEE, AF or CF at different concentrations. Then, AGS cells were exposed to H2O2 for 2 hour and viability was measured by means of the MTT reduction assay. In another experimental approach, cells were scrapped, collected by centrifugation and lysed to determine the activity of intracellular antioxidant enzymes. A significant cytoprotective effect was observed in a dosedependent manner for all species studied. The highest activity was found for R. punctatum with 55.0 7 1.8% of cell viability against 33.0 7 0.4% of survival of untreated cells. No significant difference between PEE, AF or CF in the cytoprotective effect. A significant increase in the activity of superoxide dismutase by all Ribes species was found in a dose dependent manner. Our results on the protective potential of South American Ribes species provides