- Email: [email protected]
Is autophagy involved in the response to oxidative stress of tobacco BY-2 cells overexpressing thioredoxin o1?
S164
A. Stepanova et al. / Free Radical Biology and Medicine 120 (2018) S45–S166
4
Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada 5 Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK 6 Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal 7 CNR Institute of Molecular Biology and Pathology, Rome, Italy
Cytochrome bd is a prokaryotic respiratory terminal oxidase phylogenetically unrelated to haem-copper oxidases. In addition to sustaining energy metabolism, this enzyme is implicated in bacterial protection against oxidative and nitrosative stress. Cytochrome bd is only found in prokaryotes and, as it promotes virulence in several pathogenic bacteria, it is currently recognized as a potential drug target. Escherichia coli and other microbes, including pathogens, colonize the human gut, that is known to be rich in hydrogen sulfide (H2S), while being a major site of reactive nitrogen species production. Depending on its concentration, H2S can have beneficial or detrimental effects in both prokaryotes and eukaryotes. Among the most well known toxic effects of H2S is the inhibition of cellular respiration due to binding to mitochondrial heme copper-type cytochrome c oxidase. Interestingly, working on E. coli mutant strains and purified proteins, we found that bd-type oxidases are insensitive to H2S inhibition, thereby promoting bacterial respiration and growth in the presence of high levels of H2S. The potential impact of this discovery on human (patho)physiology and its possible applications in the field of infectious diseases will be discussed.
E-mail address: [email protected] http://dx.doi.org/10.1016/j.freeradbiomed.2018.04.538
P-392
( ) Epicatechin modulates fatpads changes associated to a high-fatdiet in mice Monica Galleano 1,2,3, Ezequiel Hid 1,2,3, Maria C. Litterio 1,2,3, Jorge E. Toblli 1,2,3, Barbara Piotrkowski 1,2,3, Laura Fischerman 1,2,3, Paula D. Prince 1,2,3, Juana I. Mosse 1,2,3, Cesar G. Fraga 1,2,3 1
Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Fisicoquímica, Buenos Aires, Argentina 2 CONICET-Universidad de Buenos Aires, Instituto de Bioquímica y Medicina Molecular (IBIMOL), Buenos Aires, Argentina 3 Laboratorio de Medicina Experimental, Hospital Aleman, Buenos Aires, Argentina
E-mail address: [email protected] Acknowledgements Support: PIP 11220170100585C (MG); UBACyT 20020160100132BA (CF); Packer-Wentz endowment (CF).
http://dx.doi.org/10.1016/j.freeradbiomed.2018.04.539
P-393
Is autophagy involved in the response to oxidative stress of tobacco BY-2 cells overexpressing thioredoxin o1? O. López-Vidal 1, A. Jimenez 1, S. Sevilla 1, L.M. Sandalio 2, A. Ortiz-Espín (*)1 1
Dpt of Stress Biology and Plant Pathology, CEBAS-CSIC, Murcia, Spain 2 Dpt of Biochemistry, Cellular and Molecular Biology of Plants, EEZ-CSIC, Granada, Spain
Autophagy is a catabolic process for cellular remodeling and macromolecular recycling of cytoplasmic components and organelles. Interestingly, autophagy appears as a key mechanism to cope with adverse conditions by removing damaged cellular components, although less information exists about this process in plants. In this sense, little is known about the possible role of redox regulation through thiol oxidoreductases thioredoxins (Trxs), specifically the mitochondrial/nuclear Trxo1. We have previously described a protective role of pea thioredoxin (PsTrxo1) overexpressed in TBY-2 cells treated with H2O2, thus increasing their viability via antioxidants, delaying cell death. In this work, we analyze the possible implication of autophagy as a protective mechanism operating in the PsTrxo1 transformed TBY-2 cells. For this, together with cell viability, different markers such as autophagy-related proteins ATGs are analyzed by Western blot, in parallel to autolysosomes and autophagosomes formation by fluorescence microscopy. The results have shown significant changes in ATG4 and ATG8 contents as well as presence of both lytic structures in H2O2-treated overexpressing PsTrxo1 cells, which suggest that Trxo1 may be also involved in the redox control of some autophagy components.
E-mail address: [email protected] http://dx.doi.org/10.1016/j.freeradbiomed.2018.04.540
P-394 This work focuses on the effects of (-)-epicatechin (EC) on fat pads changes induced by high-fat (HF) diet. C57BL/6 male mice were divided in 4 groups receiving: control diet (10% calories from fat), HF diet (60% of calories), and these diets added with 20 mg EC/kg bw for 15 w. Even when caloric intake was not different among groups, HF increased mice weight. In white fat pads, inflammation (IL-6 and iNOS expression) and oxidative stress (gp91phox expression and MDA content) increases were associated with fat pad expansions. Adipocyte size was not different in HF respect to C group. On the other hand, HF diet induced expansion of aortic perivascular adipose tissue (aPVAT), with an increase of adipocyte size. Adipocytes/area were significantly lower in HF respect to C group. Changes in vacuolization patterns suggest a shift to white adipocyte phenotype, confirmed by a lower UCP-1 expression. All the observed changes in aPVAT were attenuated by EC. Since aPVAT dysfunction is relevant for hypertension and atherosclerosis, the effects of EC support an alternative nutritional strategy to avoid the progression of vascular dysfunction associated to the development of obesity.
Zinc modulates dopamine-induced heme oxygenase 1 expression in human IMR-32 neuroblastoma cells Zachary Kaufman 1, Gabriela Salvador 2, Patricia I. Oteiza 1 1
Departments of Nutrition and Environmental Toxicology, University of California, Davis, CA, USA 2 Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB-UNSCONICET). Bahía Blanca, Argentina
Zinc (Zn) plays a key role in the modulation of neuronal redox status. The present work tested the hypothesis that Zn is necessary for the neuronal defence response against dopamine (DA)-induced oxidative stress, in particular for the upregulation of heme oxigenase 1 (HMOX1).
A. Stepanova et al. / Free Radical Biology and Medicine 120 (2018) S45–S166
4
Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada 5 Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK 6 Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal 7 CNR Institute of Molecular Biology and Pathology, Rome, Italy
Cytochrome bd is a prokaryotic respiratory terminal oxidase phylogenetically unrelated to haem-copper oxidases. In addition to sustaining energy metabolism, this enzyme is implicated in bacterial protection against oxidative and nitrosative stress. Cytochrome bd is only found in prokaryotes and, as it promotes virulence in several pathogenic bacteria, it is currently recognized as a potential drug target. Escherichia coli and other microbes, including pathogens, colonize the human gut, that is known to be rich in hydrogen sulfide (H2S), while being a major site of reactive nitrogen species production. Depending on its concentration, H2S can have beneficial or detrimental effects in both prokaryotes and eukaryotes. Among the most well known toxic effects of H2S is the inhibition of cellular respiration due to binding to mitochondrial heme copper-type cytochrome c oxidase. Interestingly, working on E. coli mutant strains and purified proteins, we found that bd-type oxidases are insensitive to H2S inhibition, thereby promoting bacterial respiration and growth in the presence of high levels of H2S. The potential impact of this discovery on human (patho)physiology and its possible applications in the field of infectious diseases will be discussed.
E-mail address: [email protected] http://dx.doi.org/10.1016/j.freeradbiomed.2018.04.538
P-392
( ) Epicatechin modulates fatpads changes associated to a high-fatdiet in mice Monica Galleano 1,2,3, Ezequiel Hid 1,2,3, Maria C. Litterio 1,2,3, Jorge E. Toblli 1,2,3, Barbara Piotrkowski 1,2,3, Laura Fischerman 1,2,3, Paula D. Prince 1,2,3, Juana I. Mosse 1,2,3, Cesar G. Fraga 1,2,3 1
Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Fisicoquímica, Buenos Aires, Argentina 2 CONICET-Universidad de Buenos Aires, Instituto de Bioquímica y Medicina Molecular (IBIMOL), Buenos Aires, Argentina 3 Laboratorio de Medicina Experimental, Hospital Aleman, Buenos Aires, Argentina
E-mail address: [email protected] Acknowledgements Support: PIP 11220170100585C (MG); UBACyT 20020160100132BA (CF); Packer-Wentz endowment (CF).
http://dx.doi.org/10.1016/j.freeradbiomed.2018.04.539
P-393
Is autophagy involved in the response to oxidative stress of tobacco BY-2 cells overexpressing thioredoxin o1? O. López-Vidal 1, A. Jimenez 1, S. Sevilla 1, L.M. Sandalio 2, A. Ortiz-Espín (*)1 1
Dpt of Stress Biology and Plant Pathology, CEBAS-CSIC, Murcia, Spain 2 Dpt of Biochemistry, Cellular and Molecular Biology of Plants, EEZ-CSIC, Granada, Spain
Autophagy is a catabolic process for cellular remodeling and macromolecular recycling of cytoplasmic components and organelles. Interestingly, autophagy appears as a key mechanism to cope with adverse conditions by removing damaged cellular components, although less information exists about this process in plants. In this sense, little is known about the possible role of redox regulation through thiol oxidoreductases thioredoxins (Trxs), specifically the mitochondrial/nuclear Trxo1. We have previously described a protective role of pea thioredoxin (PsTrxo1) overexpressed in TBY-2 cells treated with H2O2, thus increasing their viability via antioxidants, delaying cell death. In this work, we analyze the possible implication of autophagy as a protective mechanism operating in the PsTrxo1 transformed TBY-2 cells. For this, together with cell viability, different markers such as autophagy-related proteins ATGs are analyzed by Western blot, in parallel to autolysosomes and autophagosomes formation by fluorescence microscopy. The results have shown significant changes in ATG4 and ATG8 contents as well as presence of both lytic structures in H2O2-treated overexpressing PsTrxo1 cells, which suggest that Trxo1 may be also involved in the redox control of some autophagy components.
E-mail address: [email protected] http://dx.doi.org/10.1016/j.freeradbiomed.2018.04.540
P-394 This work focuses on the effects of (-)-epicatechin (EC) on fat pads changes induced by high-fat (HF) diet. C57BL/6 male mice were divided in 4 groups receiving: control diet (10% calories from fat), HF diet (60% of calories), and these diets added with 20 mg EC/kg bw for 15 w. Even when caloric intake was not different among groups, HF increased mice weight. In white fat pads, inflammation (IL-6 and iNOS expression) and oxidative stress (gp91phox expression and MDA content) increases were associated with fat pad expansions. Adipocyte size was not different in HF respect to C group. On the other hand, HF diet induced expansion of aortic perivascular adipose tissue (aPVAT), with an increase of adipocyte size. Adipocytes/area were significantly lower in HF respect to C group. Changes in vacuolization patterns suggest a shift to white adipocyte phenotype, confirmed by a lower UCP-1 expression. All the observed changes in aPVAT were attenuated by EC. Since aPVAT dysfunction is relevant for hypertension and atherosclerosis, the effects of EC support an alternative nutritional strategy to avoid the progression of vascular dysfunction associated to the development of obesity.
Zinc modulates dopamine-induced heme oxygenase 1 expression in human IMR-32 neuroblastoma cells Zachary Kaufman 1, Gabriela Salvador 2, Patricia I. Oteiza 1 1
Departments of Nutrition and Environmental Toxicology, University of California, Davis, CA, USA 2 Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB-UNSCONICET). Bahía Blanca, Argentina
Zinc (Zn) plays a key role in the modulation of neuronal redox status. The present work tested the hypothesis that Zn is necessary for the neuronal defence response against dopamine (DA)-induced oxidative stress, in particular for the upregulation of heme oxigenase 1 (HMOX1).