- Email: [email protected]
P78
Abstracts / Nitric Oxide 39 (2014) S16–S49
thionine-gamma-lyase (CSE) inhibitor, and mesoporphyrin-IX, a heme oxygenase inhibitor, abolished the effect of this triterpene. In addition, aorta relaxation was reduced following blockade of potassium channels. Finally, since vasodilation elicited by triterpenes was significantly decreased by L-NAME and PAG, the six investigated compounds were docked into the endothelial NO synthase and CSE binding sites and a binding model was proposed. The present study demonstrated that NO is the main gasotransmitter responsible for relaxation induced by the triterpenes. However, H2S and CO also contribute to this effect. http://dx.doi.org/10.1016/j.niox.2014.03.126
P77
Exploring the potential of NOSH-aspirin as a plant priming agent against abiotic stress factors Chrystalla Antoniou a, Giannis Chatzimichail a, Khosrow Kashfi b, Vasileios Fotopoulos a a Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, PO BOX 50329, 3603 Limassol, Cyprus b Department of Physiology, Pharmacology, and Neuroscience, Sophie Davis School of Biomedical Education, City University of New York Medical School, New York, NY 10031, United States Terrestrial plants are constantly exposed to multiple abiotic stress factors such as drought, salinity and heat. Nitric oxide (NO) and hydrogen sulfide (H2S) are two well-documented signaling molecules, which act as priming agents, regulating the response of plants under stress condition. Several donors exist which provide plants with NO and H2S separately. NOSH is a remarkable novel donor as it can provide plants simultaneously with NO and H2S, while NOSH– aspirin additionally provides the pharmaceutical molecule acetylsalicylic acid. The present study attempts to investigate the synergistic effect of these molecules in drought-stressed Medicago truncatula L. plants. Plants were initially pre-treated with both donors (NOSH and NOSH-aspirin) by vacuum infiltration, and were then subsequently exposed to moderate water deficit. Preliminary experiments examined the extent of cellular damage in leaves by determining lipid peroxidation (MDA content) and hydrogen peroxide (H2O2) levels. Interestingly, drought-stressed plants pre-treated with either one of these compounds demonstrated significantly lower oxidative damage levels compared with non-primed stressed plants, with lowest cellular damage levels being recorded in NOSH-aspirin-treated plants. In addition, real-time RT-PCR analysis is currently underway, examining the expression of several defense-related genes including enzymatic and non-enzymatic antioxidants. Our results propose a novel role for NOSH-aspirin as a plant priming agent against abiotic stress factors, while further experiments are planned which will attempt to delve deeper in the modus operandi of this hybrid compound.
S39
b
Faculty of Medicine, Tokyo University, Tokyo, Japan Faculty of Pharmaceutical Science, Tokyo University of Science, Chiba, Japan c
Accumulating evidence shows that hydrogen sulfide (H2S) has a variety of physiological functions. H2S is produced from cysteine by 3 sulfurtransferases. H2S, in turn, generates polysulfides, the functions of which are not well understood. H2S induces Ca2+ influx in astrocytes, a type of glia. However, the receptor that mediates the response has not been identified. Here, we have shown that polysulfides induce Ca2+ influx by activating transient receptor potential (TRP) A1 channels in rat astrocytes (EC50 91 nM, Hill coefficient value 1.77 ± 0.26) and that the maximum response was induced at 0.5 microM, which is 1/320 of the concentration of H2S required to achieve a response of similar magnitude (160 microM, EC50 116 microM). TRPA1-selective agonists, allyl isothiocyanate and cinnamaldehyde, induced Ca2+ influx, and responses to polysulfides were suppressed by TRPA1-selective inhibitors, HC-030031 and AP-18, as well as by siRNAs selective to TRPA1. The present study suggests that polysulfides are possible H2S -derived signaling molecules that stimulate TRP channels in the brain.
http://dx.doi.org/10.1016/j.niox.2014.03.128
P79 Polysulfide exerts protective effect against cytotoxicity through Nrf2 signaling in neuronal cells Shin Koike a, Yuki Ogasawara a, Norihiro Shibuya b, Kazuyuki Ishii a, Hideo Kimura b a Department of Analytical Biochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan b Department of Molecular Pharmacology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan Polysulfide is a bound sulfur species derived from endogenous H2S. When mouse neuroblastoma, Neuro2A cells were exposed to tert-butyl hydroperoxide after treatment with polysulfide, a significant decline in cell toxicity was observed. Rapid uptake of polysulfides induced translocation of Nrf2 into the nucleus, resulting in acceleration of GSH synthesis and HO-1 expression. We demonstrated that polysulfide reversibly modified Keap1 to form oxidized dimers and induced the translocation of Nrf2. Moreover, polysulfide treatment accelerated Akt phosphorylation, which is a known pathway of Nrf2 phosphorylation. Thus, polysulfide may mediate the activation of Nrf2 signaling, thereby exerting protective effects against oxidative damage in Neuro2A cells.
http://dx.doi.org/10.1016/j.niox.2014.03.127 http://dx.doi.org/10.1016/j.niox.2014.03.129
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P80
Polysulfides are possible H2S-derived signaling molecules in rat brain
Hydrogen sulphide impairs bioactivity of nitric oxide by superoxide-dependent and -independent mechanisms
Yuka Kimura a, Yoshinori Mikami b, Kimiko Osumi a, Mamiko Tsugane a, Jun-ichiro Oka c, Hideo Kimura a a Department of Molecular Pharmacology, National Institute of Neuroscience, Tokyo, Japan
Bernd Kolesnik a, Burkhard Kloesch b, Guenter Steiner b,c, Antonius C.F. Gorren a, Bernd Mayer a, Kurt Schmidt a a Karl-Franzens-University Graz, Department of Pharmacology and Toxicology, Graz, Austria
thionine-gamma-lyase (CSE) inhibitor, and mesoporphyrin-IX, a heme oxygenase inhibitor, abolished the effect of this triterpene. In addition, aorta relaxation was reduced following blockade of potassium channels. Finally, since vasodilation elicited by triterpenes was significantly decreased by L-NAME and PAG, the six investigated compounds were docked into the endothelial NO synthase and CSE binding sites and a binding model was proposed. The present study demonstrated that NO is the main gasotransmitter responsible for relaxation induced by the triterpenes. However, H2S and CO also contribute to this effect. http://dx.doi.org/10.1016/j.niox.2014.03.126
P77
Exploring the potential of NOSH-aspirin as a plant priming agent against abiotic stress factors Chrystalla Antoniou a, Giannis Chatzimichail a, Khosrow Kashfi b, Vasileios Fotopoulos a a Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, PO BOX 50329, 3603 Limassol, Cyprus b Department of Physiology, Pharmacology, and Neuroscience, Sophie Davis School of Biomedical Education, City University of New York Medical School, New York, NY 10031, United States Terrestrial plants are constantly exposed to multiple abiotic stress factors such as drought, salinity and heat. Nitric oxide (NO) and hydrogen sulfide (H2S) are two well-documented signaling molecules, which act as priming agents, regulating the response of plants under stress condition. Several donors exist which provide plants with NO and H2S separately. NOSH is a remarkable novel donor as it can provide plants simultaneously with NO and H2S, while NOSH– aspirin additionally provides the pharmaceutical molecule acetylsalicylic acid. The present study attempts to investigate the synergistic effect of these molecules in drought-stressed Medicago truncatula L. plants. Plants were initially pre-treated with both donors (NOSH and NOSH-aspirin) by vacuum infiltration, and were then subsequently exposed to moderate water deficit. Preliminary experiments examined the extent of cellular damage in leaves by determining lipid peroxidation (MDA content) and hydrogen peroxide (H2O2) levels. Interestingly, drought-stressed plants pre-treated with either one of these compounds demonstrated significantly lower oxidative damage levels compared with non-primed stressed plants, with lowest cellular damage levels being recorded in NOSH-aspirin-treated plants. In addition, real-time RT-PCR analysis is currently underway, examining the expression of several defense-related genes including enzymatic and non-enzymatic antioxidants. Our results propose a novel role for NOSH-aspirin as a plant priming agent against abiotic stress factors, while further experiments are planned which will attempt to delve deeper in the modus operandi of this hybrid compound.
S39
b
Faculty of Medicine, Tokyo University, Tokyo, Japan Faculty of Pharmaceutical Science, Tokyo University of Science, Chiba, Japan c
Accumulating evidence shows that hydrogen sulfide (H2S) has a variety of physiological functions. H2S is produced from cysteine by 3 sulfurtransferases. H2S, in turn, generates polysulfides, the functions of which are not well understood. H2S induces Ca2+ influx in astrocytes, a type of glia. However, the receptor that mediates the response has not been identified. Here, we have shown that polysulfides induce Ca2+ influx by activating transient receptor potential (TRP) A1 channels in rat astrocytes (EC50 91 nM, Hill coefficient value 1.77 ± 0.26) and that the maximum response was induced at 0.5 microM, which is 1/320 of the concentration of H2S required to achieve a response of similar magnitude (160 microM, EC50 116 microM). TRPA1-selective agonists, allyl isothiocyanate and cinnamaldehyde, induced Ca2+ influx, and responses to polysulfides were suppressed by TRPA1-selective inhibitors, HC-030031 and AP-18, as well as by siRNAs selective to TRPA1. The present study suggests that polysulfides are possible H2S -derived signaling molecules that stimulate TRP channels in the brain.
http://dx.doi.org/10.1016/j.niox.2014.03.128
P79 Polysulfide exerts protective effect against cytotoxicity through Nrf2 signaling in neuronal cells Shin Koike a, Yuki Ogasawara a, Norihiro Shibuya b, Kazuyuki Ishii a, Hideo Kimura b a Department of Analytical Biochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan b Department of Molecular Pharmacology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan Polysulfide is a bound sulfur species derived from endogenous H2S. When mouse neuroblastoma, Neuro2A cells were exposed to tert-butyl hydroperoxide after treatment with polysulfide, a significant decline in cell toxicity was observed. Rapid uptake of polysulfides induced translocation of Nrf2 into the nucleus, resulting in acceleration of GSH synthesis and HO-1 expression. We demonstrated that polysulfide reversibly modified Keap1 to form oxidized dimers and induced the translocation of Nrf2. Moreover, polysulfide treatment accelerated Akt phosphorylation, which is a known pathway of Nrf2 phosphorylation. Thus, polysulfide may mediate the activation of Nrf2 signaling, thereby exerting protective effects against oxidative damage in Neuro2A cells.
http://dx.doi.org/10.1016/j.niox.2014.03.127 http://dx.doi.org/10.1016/j.niox.2014.03.129
P78
P80
Polysulfides are possible H2S-derived signaling molecules in rat brain
Hydrogen sulphide impairs bioactivity of nitric oxide by superoxide-dependent and -independent mechanisms
Yuka Kimura a, Yoshinori Mikami b, Kimiko Osumi a, Mamiko Tsugane a, Jun-ichiro Oka c, Hideo Kimura a a Department of Molecular Pharmacology, National Institute of Neuroscience, Tokyo, Japan
Bernd Kolesnik a, Burkhard Kloesch b, Guenter Steiner b,c, Antonius C.F. Gorren a, Bernd Mayer a, Kurt Schmidt a a Karl-Franzens-University Graz, Department of Pharmacology and Toxicology, Graz, Austria