Singlet molecular oxygen regulates vascular tone and blood pressure in inflammation
- Stanley, Christopher, Maghzal, Ghassan, Ayer, Anita, Talib, Jihan, Giltrap, Andrew, Shengule, Sudhir, Wolhuter, Kathryn, Wang, Yutang, Chadha, Preet, Suarna, Cacang, Prysyazhna, Oleksandra, Scotcher, Jenna, Dunn, Louise, Prado, Fernanda, Nguyen, Nghi, Odiba, Jephthah, Baell, Johathan, Stasch, Johannes-Peter, Yamamoto, Yorihiro, Di Mascio, Paolo, Eaton, Philip, Payne, Richard, Stocker, Roland
- Authors: Stanley, Christopher , Maghzal, Ghassan , Ayer, Anita , Talib, Jihan , Giltrap, Andrew , Shengule, Sudhir , Wolhuter, Kathryn , Wang, Yutang , Chadha, Preet , Suarna, Cacang , Prysyazhna, Oleksandra , Scotcher, Jenna , Dunn, Louise , Prado, Fernanda , Nguyen, Nghi , Odiba, Jephthah , Baell, Johathan , Stasch, Johannes-Peter , Yamamoto, Yorihiro , Di Mascio, Paolo , Eaton, Philip , Payne, Richard , Stocker, Roland
- Date: 2019
- Type: Text , Journal article , Letter
- Relation: Nature Vol. 566, no. 7745 (2019), p. 548-552
- Full Text:
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- Description: Singlet molecular oxygen (O-1(2)) has well-established roles in photosynthetic plants, bacteria and fungi(1-3), but not in mammals. Chemically generated O-1(2) oxidizes the amino acid tryptophan to precursors of a key metabolite called N-formylkynurenine(4), whereas enzymatic oxidation of tryptophan to N-formylkynurenine is catalysed by a family of dioxygenases, including indoleamine 2,3-dioxygenase 1(5). Under inflammatory conditions, this haem-containing enzyme is expressed in arterial endothelial cells, where it contributes to the regulation of blood pressure(6). However, whether indoleamine 2,3-dioxygenase 1 forms O-1(2) and whether this contributes to blood pressure control have remained unknown. Here we show that arterial indoleamine 2,3-dioxygenase 1 regulates blood pressure via formation of O-1(2). We observed that in the presence of hydrogen peroxide, the enzyme generates O-1(2) and that this is associated with the stereoselective oxidation of L-tryptophan to a tricyclic hydroperoxide via a previously unrecognized oxidative activation of the dioxygenase activity. The tryptophan-derived hydroperoxide acts in vivo as a signalling molecule, inducing arterial relaxation and decreasing blood pressure; this activity is dependent on Cys42 of protein kinase G1 alpha. Our findings demonstrate a pathophysiological role for O-1(2) in mammals through formation of an amino acid-derived hydroperoxide that regulates vascular tone and blood pressure under inflammatory conditions.
- Authors: Stanley, Christopher , Maghzal, Ghassan , Ayer, Anita , Talib, Jihan , Giltrap, Andrew , Shengule, Sudhir , Wolhuter, Kathryn , Wang, Yutang , Chadha, Preet , Suarna, Cacang , Prysyazhna, Oleksandra , Scotcher, Jenna , Dunn, Louise , Prado, Fernanda , Nguyen, Nghi , Odiba, Jephthah , Baell, Johathan , Stasch, Johannes-Peter , Yamamoto, Yorihiro , Di Mascio, Paolo , Eaton, Philip , Payne, Richard , Stocker, Roland
- Date: 2019
- Type: Text , Journal article , Letter
- Relation: Nature Vol. 566, no. 7745 (2019), p. 548-552
- Full Text:
- Reviewed:
- Description: Singlet molecular oxygen (O-1(2)) has well-established roles in photosynthetic plants, bacteria and fungi(1-3), but not in mammals. Chemically generated O-1(2) oxidizes the amino acid tryptophan to precursors of a key metabolite called N-formylkynurenine(4), whereas enzymatic oxidation of tryptophan to N-formylkynurenine is catalysed by a family of dioxygenases, including indoleamine 2,3-dioxygenase 1(5). Under inflammatory conditions, this haem-containing enzyme is expressed in arterial endothelial cells, where it contributes to the regulation of blood pressure(6). However, whether indoleamine 2,3-dioxygenase 1 forms O-1(2) and whether this contributes to blood pressure control have remained unknown. Here we show that arterial indoleamine 2,3-dioxygenase 1 regulates blood pressure via formation of O-1(2). We observed that in the presence of hydrogen peroxide, the enzyme generates O-1(2) and that this is associated with the stereoselective oxidation of L-tryptophan to a tricyclic hydroperoxide via a previously unrecognized oxidative activation of the dioxygenase activity. The tryptophan-derived hydroperoxide acts in vivo as a signalling molecule, inducing arterial relaxation and decreasing blood pressure; this activity is dependent on Cys42 of protein kinase G1 alpha. Our findings demonstrate a pathophysiological role for O-1(2) in mammals through formation of an amino acid-derived hydroperoxide that regulates vascular tone and blood pressure under inflammatory conditions.
- Shen, Yu, Ward, Natalie, Hodgson, Jonathan, Puddey, Ian, Wang, Yutang, Zhang, Di, Maghzal, Ghassan, Stocker, Roland, Croft, Kevin
- Authors: Shen, Yu , Ward, Natalie , Hodgson, Jonathan , Puddey, Ian , Wang, Yutang , Zhang, Di , Maghzal, Ghassan , Stocker, Roland , Croft, Kevin
- Date: 2013
- Type: Text , Journal article
- Relation: Free Radical Biology and Medicine Vol. 65, no. (2013), p. 908-915
- Full Text: false
- Reviewed:
- Description: Several lines of evidence indicate that quercetin, a polyphenol derived in the diet from fruit and vegetables, contributes to cardiovascular health. We aimed to investigate the effects of dietary quercetin on endothelial function and atherosclerosis in mice fed a high-fat diet. Wild-type C57BL/6 (WT) and apolipoprotein E gene knockout (ApoE-/-) mice were fed: (i) a high-fat diet (HFD) or (ii) a HFD supplemented with 0.05% w/w quercetin (HFD+Q), for 14 weeks. Compared with animals fed HFD, HFD+Q attenuated atherosclerosis in ApoE-/- mice. Treatment with the HFD+Q significantly improved endothelium-dependent relaxation of aortic rings isolated from WT but not ApoE-/- mice and attenuated hypochlorous acid-induced endothelial dysfunction in aortic rings of both WT and ApoE-/- mice. Mechanistic studies revealed that HFD+Q significantly improved plasma F2- isoprostanes, 24 h urinary nitrite, and endothelial nitric oxide synthase activity, and increased heme oxygenase-1 (HO-1) protein expression in the aortas of both WT and ApoE-/- mice (P<0.05). HFD+Q also resulted in small changes in plasma cholesterol (P<0.05 in WT) and plasma triacylglycerols (P<0.05 in ApoE -/-mice). In a separate experiment, quercetin did not protect against hypochlorite-induced endothelial dysfunction in arteries obtained from heterozygous HO-1 gene knockout mice with low expression of HO-1 protein. Quercetin protects mice fed a HFD against oxidant-induced endothelial dysfunction and ApoE-/- mice against atherosclerosis. These effects are associated with improvements in nitric oxide bioavailability and are critically related to arterial induction of HO-1. © 2013 Elsevier Inc.
- Shen, Yu, Ward, Natalie, Hodgson, Jonathan, Puddey, Ian, Wang, Yutang, Zhang, Di, Maghzal, Ghassan, Stocker, Roland, Croft, Kevin
- Authors: Shen, Yu , Ward, Natalie , Hodgson, Jonathan , Puddey, Ian , Wang, Yutang , Zhang, Di , Maghzal, Ghassan , Stocker, Roland , Croft, Kevin
- Date: 2013
- Type: Text , Journal article
- Relation: Free Radical Biology and Medicine Vol. 65, no. (2013), p. 908-915
- Full Text: false
- Reviewed:
- Description: Several lines of evidence indicate that quercetin, a polyphenol derived in the diet from fruit and vegetables, contributes to cardiovascular health. We aimed to investigate the effects of dietary quercetin on endothelial function and atherosclerosis in mice fed a high-fat diet. Wild-type C57BL/6 (WT) and apolipoprotein E gene knockout (ApoE−/−) mice were fed: (i) a high-fat diet (HFD) or (ii) a HFD supplemented with 0.05% w/w quercetin (HFD+Q), for 14 weeks. Compared with animals fed HFD, HFD+Q attenuated atherosclerosis in ApoE−/− mice. Treatment with the HFD+Q significantly improved endothelium-dependent relaxation of aortic rings isolated from WT but not ApoE−/− mice and attenuated hypochlorous acid-induced endothelial dysfunction in aortic rings of both WT and ApoE−/− mice. Mechanistic studies revealed that HFD+Q significantly improved plasma F2-isoprostanes, 24h urinary nitrite, and endothelial nitric oxide synthase activity, and increased heme oxygenase-1 (HO-1) protein expression in the aortas of both WT and ApoE−/− mice (P<0.05). HFD+Q also resulted in small changes in plasma cholesterol (P<0.05 in WT) and plasma triacylglycerols (P<0.05 in ApoE −/−mice). In a separate experiment, quercetin did not protect against hypochlorite-induced endothelial dysfunction in arteries obtained from heterozygous HO-1 gene knockout mice with low expression of HO-1 protein. Quercetin protects mice fed a HFD against oxidant-induced endothelial dysfunction and ApoE−/− mice against atherosclerosis. These effects are associated with improvements in nitric oxide bioavailability and are critically related to arterial induction of HO-1. •Quercetin is an important dietary flavonoid that can reduce atherosclerosis in animal models.•Dietary quercetin improved oxidant-induced vascular dysfunction in mice.•Quercetin reduced oxidative stress, increased endothelial eNOS activity, and increased heme oxygenase-1 protein expression in aortic tissue.•Protection against oxidant-induced vascular dysfunction was critically related to arterial induction of HO-1 expression.
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