Stephen P Gray1, Elyse Di Marco2, Kit Kennedy2, Phyllis Chew2, Jun Okabe2, Assam El-Osta2, Anna C Calkin2, Erik A L Biessen2, Rhian M Touyz2, Mark E Cooper2, Harald H H W Schmidt2, Karin A M Jandeleit-Dahm2. 1. From the Diabetic Complications Laboratory (S.P.G., E.D.M., K.K., P.C., M.E.C., K.A.M.J.-D.), Epigenetics Laboratory (J.O., A.E.-O.), and Diabetes and Dyslipidaemia Group (A.C.C.), Baker IDI Heart and Diabetes Institute, Melbourne, Australia; Faculty of Medicine, Monash University, Melbourne, Australia (S.P.G., E.D.M., K.A.M.J.-D.); Department of Pathology, Maastricht University Medical Center, Maastricht, The Netherlands (E.A.L.B.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); and Department of Pharmacology, Cardiovascular Research Institute Maastricht (CARIM), Faculty of Medicine, Health, and Life Science, Maastricht University, Maastricht, The Netherlands (H.H.H.W.S.). Stephen.gray@bakeridi.edu.au. 2. From the Diabetic Complications Laboratory (S.P.G., E.D.M., K.K., P.C., M.E.C., K.A.M.J.-D.), Epigenetics Laboratory (J.O., A.E.-O.), and Diabetes and Dyslipidaemia Group (A.C.C.), Baker IDI Heart and Diabetes Institute, Melbourne, Australia; Faculty of Medicine, Monash University, Melbourne, Australia (S.P.G., E.D.M., K.A.M.J.-D.); Department of Pathology, Maastricht University Medical Center, Maastricht, The Netherlands (E.A.L.B.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); and Department of Pharmacology, Cardiovascular Research Institute Maastricht (CARIM), Faculty of Medicine, Health, and Life Science, Maastricht University, Maastricht, The Netherlands (H.H.H.W.S.).
Abstract
OBJECTIVE: Oxidative stress is considered a hallmark of atherosclerosis. In particular, the superoxide-generating type 1 NADPH oxidase (NOX1) has been shown to be induced and play a pivotal role in early phases of mouse models of atherosclerosis and in the context of diabetes mellitus. Here, we investigated the role of the most abundant type 4 isoform (NOX4) in human and mouse advanced atherosclerosis. APPROACH AND RESULTS: Plaques of patients with cardiovascular events or established diabetes mellitus showed a surprising reduction in expression of the most abundant but hydrogen peroxide (H2O2)-generating type 4 isoform (Nox4), whereas Nox1 mRNA was elevated, when compared with respective controls. As these data suggested that NOX4-derived reactive oxygen species may convey a surprisingly protective effect during plaque progression, we examined a mouse model of accelerated and advanced diabetic atherosclerosis, the streptozotocin-treated ApoE(-/-) mouse, with (NOX4(-/-)) and without genetic deletion of Nox4. Similar to the human data, advanced versus early plaques of wild-type mice showed reduced Nox4 mRNA expression. Consistent with a rather protective role of NOX4-derived reactive oxygen species, NOX4(-/-) mice showed increased atherosclerosis when compared with wild-type mice. Deleting NOX4 was associated with reduced H2O2 forming activity and attenuation of the proinflammatory markers, monocyte chemotratic protein-1, interleukin-1β, and tumor necrosis factor-α, as well as vascular macrophage accumulation. Furthermore, there was a greater accumulation of fibrillar collagen fibres within the vascular wall and plaque in diabetic Nox4(-/-)ApoE(-/-) mice, indicative of plaque remodeling. These data could be replicated in human aortic endothelial cells in vitro, where Nox4 overexpression increased H2O2 and reduced the expression of pro-oxidants and profibrotic markers. Interestingly, Nox4 levels inversely correlated with Nox2 gene and protein levels. Although NOX2 is not constitutively active unlike NOX4 and forms rather superoxide, this opens up the possibility that at least some effects of NOX4 deletion are mediated by NOX2 activation. CONCLUSIONS: Thus, the appearance of reactive oxygen species in atherosclerosis is apparently not always a nondesirable oxidative stress, but can also have protective effects. Both in humans and in mouse, the H2O2-forming NOX4, unlike the superoxide-forming NOX1, can act as a negative modulator of inflammation and remodeling and convey atheroprotection. These results have implications on how to judge reactive oxygen species formation in cardiovascular disease and need to be considered in the development of NOX inhibitory drugs.
OBJECTIVE: Oxidative stress is considered a hallmark of atherosclerosis. In particular, the superoxide-generating type 1 NADPH oxidase (NOX1) has been shown to be induced and play a pivotal role in early phases of mouse models of atherosclerosis and in the context of diabetes mellitus. Here, we investigated the role of the most abundant type 4 isoform (NOX4) in human and mouse advanced atherosclerosis. APPROACH AND RESULTS: Plaques of patients with cardiovascular events or established diabetes mellitus showed a surprising reduction in expression of the most abundant but hydrogen peroxide (H2O2)-generating type 4 isoform (Nox4), whereas Nox1 mRNA was elevated, when compared with respective controls. As these data suggested that NOX4-derived reactive oxygen species may convey a surprisingly protective effect during plaque progression, we examined a mouse model of accelerated and advanced diabetic atherosclerosis, the streptozotocin-treated ApoE(-/-) mouse, with (NOX4(-/-)) and without genetic deletion of Nox4. Similar to the human data, advanced versus early plaques of wild-type mice showed reduced Nox4 mRNA expression. Consistent with a rather protective role of NOX4-derived reactive oxygen species, NOX4(-/-) mice showed increased atherosclerosis when compared with wild-type mice. Deleting NOX4 was associated with reduced H2O2 forming activity and attenuation of the proinflammatory markers, monocyte chemotratic protein-1, interleukin-1β, and tumor necrosis factor-α, as well as vascular macrophage accumulation. Furthermore, there was a greater accumulation of fibrillar collagen fibres within the vascular wall and plaque in diabetic Nox4(-/-)ApoE(-/-) mice, indicative of plaque remodeling. These data could be replicated in human aortic endothelial cells in vitro, where Nox4 overexpression increased H2O2 and reduced the expression of pro-oxidants and profibrotic markers. Interestingly, Nox4 levels inversely correlated with Nox2 gene and protein levels. Although NOX2 is not constitutively active unlike NOX4 and forms rather superoxide, this opens up the possibility that at least some effects of NOX4 deletion are mediated by NOX2 activation. CONCLUSIONS: Thus, the appearance of reactive oxygen species in atherosclerosis is apparently not always a nondesirable oxidative stress, but can also have protective effects. Both in humans and in mouse, the H2O2-forming NOX4, unlike the superoxide-forming NOX1, can act as a negative modulator of inflammation and remodeling and convey atheroprotection. These results have implications on how to judge reactive oxygen species formation in cardiovascular disease and need to be considered in the development of NOX inhibitory drugs.
Authors: Steven J Forrester; Daniel S Kikuchi; Marina S Hernandes; Qian Xu; Kathy K Griendling Journal: Circ Res Date: 2018-03-16 Impact factor: 17.367
Authors: C Veith; S Kraut; J Wilhelm; N Sommer; K Quanz; W Seeger; R P Brandes; N Weissmann; K Schröder Journal: Pulm Circ Date: 2016-09 Impact factor: 3.017
Authors: Andrey Lozhkin; Aleksandr E Vendrov; Hua Pan; Samuel A Wickline; Nageswara R Madamanchi; Marschall S Runge Journal: J Mol Cell Cardiol Date: 2016-12-14 Impact factor: 5.000
Authors: Hong S Lu; Ann Marie Schmidt; Robert A Hegele; Nigel Mackman; Daniel J Rader; Christian Weber; Alan Daugherty Journal: Arterioscler Thromb Vasc Biol Date: 2018-10 Impact factor: 8.311
Authors: Elyse Di Marco; Stephen P Gray; Kit Kennedy; Cedric Szyndralewiez; Alicia N Lyle; Bernard Lassègue; Kathy K Griendling; Mark E Cooper; Harald H H W Schmidt; Karin A M Jandeleit-Dahm Journal: Free Radic Biol Med Date: 2016-07-19 Impact factor: 7.376
Authors: Pingping Hu; Xiaojuan Wu; Alok R Khandelwal; Weimin Yu; Zaicheng Xu; Lili Chen; Jian Yang; Robert M Weisbrod; Kin Sing Stephen Lee; Francesca Seta; Bruce D Hammock; Richard A Cohen; Chunyu Zeng; Xiaoyong Tong Journal: Biochim Biophys Acta Mol Basis Dis Date: 2017-02-07 Impact factor: 5.187