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Kathy K. Griendling - One of the best experts on this subject based on the ideXlab platform.
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functional association of nox1 with P22phox in vascular smooth muscle cells
Free Radical Biology and Medicine, 2004Co-Authors: Ibrahim R Hanna, Bernard Lassegue, Alicia N Lyle, Lula Hilenski, Anna Dikalova, Yoshihiro Taniyama, Sergey Dikalov, Mark T Quinn, Kathy K. GriendlingAbstract:Abstract The vascular NAD(P)H oxidases constitute important sources of ROS in the vessel wall and have been implicated in vascular disease. Vascular smooth muscle cells (VSMCs) from conduit arteries express two gp91phox homologs, Nox1 and Nox4, of which Nox1 is agonist-sensitive. Because P22phox has been shown to be functionally important in vascular cells stimulated with vasoactive hormones, the relationship of Nox1 and P22phox was investigated in VSMCs from rat and human aortas. Coimmunoprecipitation studies demonstrated that P22phox and hemagglutinin-tagged Nox1 associate in unstimulated VSMCs. These findings were confirmed by confocal microscopy, showing colocalization of the two proteins in their native states in the plasma membrane and submembrane areas of the cell. NADPH-driven superoxide production, as measured by electron spin resonance using 1-hydroxy-3-carboxypyrrolidine as a spin probe, is dependent on the coexpression of both subunits, suggesting the importance of the association for the functional integrity of the enzyme. These results indicate that in contrast to the neutrophil enzyme, VSMCs can use Nox1 rather than gp91phox as a catalytic center in the P22phox-based oxidase and that these two proteins are preassembled at or near the plasma membrane and submembrane vesicular structures in unstimulated cells.
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direct interaction of the novel nox proteins with P22phox is required for the formation of a functionally active nadph oxidase
Journal of Biological Chemistry, 2004Co-Authors: Rashmi K Ambasta, Kathy K. Griendling, Harald H H W Schmidt, Pravir Kumar, Rudi Busse, Ralf P BrandesAbstract:Abstract Nox1 and Nox4, homologues of the leukocyte NADPH oxidase subunit Nox2 (gp91phox) mediate superoxide anion formation in various cell types. However, their interactions with other components of the NADPH oxidase are poorly defined. We determined whether a direct interaction of Nox1 and Nox4 with the P22phox subunit of the NADPH oxidase occurs. Using confocal microscopy, co-localization of P22phox with Nox1, Nox2, and Nox4 was observed in transiently transfected vascular smooth muscle cells (VSMC) and HEK293 cells. Plasmids coding for fluorescent fusion proteins of P22phox and the Nox proteins with cyan- and yellow-fluorescent protein (cfp and yfp, respectively) were constructed and expressed in VSMC and HEK293 cells. The cfp-tagged P22phox expression level increased upon cotransfection with Nox1 or Nox4. Protein-protein interaction between the fluorescent fusion proteins of P22phox and the Nox partners was observed using the fluorescence resonance energy transfer technique. Immunoprecipitation of native Nox1 from human VSMC revealed co-precipitation of P22phox. Immunoprecipitation from transfected HEK293 cells revealed co-precipitation of native P22phox with yfp-tagged Nox1, Nox2, and Nox4. Following mutation of a histidine (corresponding to the position 115 in human Nox2) to leucine, this interaction was abolished. Transfection of rat P22phox (but not Noxo1 and Noxa1) increased the radical generation in cells expressing Nox4. We provide evidence that P22phox directly interacts with Nox1 and Nox4, to form an superoxide-generating NADPH oxidase and demonstrate that mutation of the potential heme binding site in the Nox proteins disrupts the complex formation of Nox1 and Nox4 with P22phox.
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tumour necrosis factor alpha activates a P22phox based nadh oxidase in vascular smooth muscle
Biochemical Journal, 1998Co-Authors: Gilles W De Keulenaer, Nobukazu Ishizaka, Masuko Ushiofukai, Wayne R Alexander, Kathy K. GriendlingAbstract:Increasing experimental evidence suggests that non-phagocytic cells express a potent superoxide (O2-.)-producing NADH oxidase that might be related to the phagocytic NADPH oxidase. Here we show that the cytokine tumour necrosis factor alpha (TNF-alpha) activates, in a time- and dose-dependent manner, a O2-.-producing NADH oxidase in cultured rat aortic smooth-muscle cells. Dose-response experiments for NADH showed an upward shift of the curve for TNF-alpha-treated cells, suggesting that TNF-alpha increased the amount of available enzyme. Using the anti-sense transfection technique, we further demonstrate that the molecular identity of this oxidase includes p22(phox) (the alpha subunit of cytochrome b558 and part of the electron transfer component of the phagocytic NADPH oxidase), which we recently cloned from a rat vascular smooth-muscle cell cDNA library. In addition, prolonged treatment with TNF-alpha increased P22phox mRNA expression without affecting P22phox mRNA stability, and only when transcriptional activity was intact. These findings identify a P22phox-containing NADH oxidase as a source for cytokine-induced free radical production in vascular smooth-muscle cells and clarify some of the mechanisms involved in the regulation of vascular oxidase activity.
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P22phox mRNA Expression and NADPH Oxidase Activity Are Increased in Aortas From Hypertensive Rats
Circulation research, 1997Co-Authors: Toshiki Fukui, Nobukazu Ishizaka, Sanjay Rajagopalan, Jørn Bech Laursen, Quinn Capers, W. Robert Taylor, David G. Harrison, Hector De Leon, Josiah N. Wilcox, Kathy K. GriendlingAbstract:Recent studies suggest that superoxide production by the NADPH/NADH oxidase may be involved in smooth muscle cell growth and the pathogenesis of hypertension. We previously showed that angiotensin II (Ang II) activates a P22phox-based NADPH/NADH oxidase in cultured rat vascular smooth muscle cells and in animals made hypertensive by infusion of Ang II. To investigate the mechanism responsible for this increased oxidase activity, we examined P22phox mRNA expression in rats made hypertensive by implanting an osmotic minipump that delivered Ang II (0.7 mg/kg per day). Blood pressure began to increase 3 days after the start of Ang II infusion and remained elevated for up to 14 days. Expression of P22phox mRNA in aorta was also increased after 3 days and reached a maximum increase of 338±41% by 5 days after pump implantation compared with the value after sham operation. This increase in mRNA expression was accompanied by an increase in the content of the corresponding cytochrome (twofold) and NADPH oxidase activity (179±11% of that in sham-operated rats 5 days after pump implantation). Treatment with the antihypertensive agents losartan (25 mg/kg per day) or hydralazine (15 mg/kg per day) inhibited this upregulation of mRNA levels and activity. Furthermore, infusion of recombinant heparin-binding superoxide dismutase decreased both blood pressure and P22phox mRNA expression. In situ hybridization of aortic tissue showed that P22phox mRNA was expressed in medial smooth muscle as well as in the adventitia. These findings suggest that Ang II–induced hypertension activates the NADPH/NADH oxidase system by upregulating mRNA levels of one or several components of this oxidase system, including the P22phox, and that the NADPH/NADH oxidase system is associated with the pathology of hypertension in vivo.
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P22phox is a critical component of the superoxide generating nadh nadph oxidase system and regulates angiotensin ii induced hypertrophy in vascular smooth muscle cells
Journal of Biological Chemistry, 1996Co-Authors: Masuko Ushiofukai, Maziar A Zafari, Toshiki Fukui, Nobukazu Ishizaka, Kathy K. GriendlingAbstract:Abstract Superoxide anion formation is vital to the microbicidal activity of phagocytes. Recently, however, there is accumulating evidence that it is also involved in cell growth in vascular smooth muscle cells (VSMCs). We have shown that the hypertrophic agent angiotensin II stimulates superoxide production by activating the membrane-bound NADH/NADPH oxidase and that inhibition of this oxidase attenuates vascular hypertrophy. However, the molecular identity of this oxidase in VSMCs is unknown. We have recently cloned the cytochrome b558 α-subunit, P22phox (one of the key electron transfer elements of the NADPH oxidase in phagocytes), from a rat VSMC cDNA library, but its role in VSMC oxidase activity remains unclarified. Here we report that the complete inhibition of P22phox mRNA expression by stable transfection of antisense P22phox cDNA into VSMCs results in a decrease in cytochrome b content, which is accompanied by a significant inhibition of angiotensin II-stimulated NADH/NADPH-dependent superoxide production, subsequent hydrogen peroxide production, and [3H]leucine incorporation. We provide the first evidence that P22phox is a critical component of superoxide-generating vascular NADH/NADPH oxidase and suggest a central role for this oxidase system in vascular hypertrophy.
Hideki Sumimoto - One of the best experts on this subject based on the ideXlab platform.
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Activation of the superoxide-producing phagocyte NADPH oxidase requires co-operation between the tandem SH3 domains of p47phox in recognition of a polyproline type II helix and an adjacent α-helix of P22phox
The Biochemical journal, 2006Co-Authors: Ikuo Nobuhisa, Ryu Takeya, Kenji Ogura, Noriko Ueno, Daisuke Kohda, Fuyuhiko Inagaki, Hideki SumimotoAbstract:Activation of the superoxide-producing phagocyte NADPH oxidase, crucial for host defence, requires an SH3 (Src homology 3)-domain-mediated interaction of the regulatory protein p47phox with P22phox, a subunit of the oxidase catalytic core flavocytochrome b558. Although previous analysis of a crystal structure has demonstrated that the tandem SH3 domains of p47phox sandwich a short PRR (proline-rich region) of P22phox (amino acids 151-160), containing a polyproline II helix, it has remained unknown whether this model is indeed functional in activation of the oxidase. In the present paper we show that the co-operativity between the two SH3 domains of p47phox, as expected from the model, is required for oxidase activation. Deletion of the linker between the p47phox SH3 domains results not only in a defective binding to P22phox but also in a loss of the activity to support superoxide production. The present analysis using alanine-scanning mutagenesis identifies Pro152, Pro156 and Arg158 in the P22phox PRR as residues indispensable for the interaction with p47phox. Pro152 and Pro156 are recognized by the N-terminal SH3 domain, whereas Arg158 contacts with the C-terminal SH3 domain. Amino acid substitution for any of the three residues in the P22phox PRR abrogates the superoxide-producing activity of the oxidase reconstituted in intact cells. The bis-SH3-mediated interaction of p47phox with P22phox thus functions to activate the phagocyte oxidase. Furthermore, we provide evidence that a region C-terminal to the PRR of P22phox (amino acids 161-164), adopting an a-helical conformation, participates in full activation of the phagocyte oxidase by fortifying the association with the p47phox SH3 domains.
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NMR Solution Structure of the Tandem Src Homology 3 Domains of p47phox Complexed with a P22phox-derived Proline-rich Peptide
The Journal of biological chemistry, 2005Co-Authors: Kenji Ogura, Ikuo Nobuhisa, Ryu Takeya, Hideki Sumimoto, Satoru Yuzawa, Shinnosuke Torikai, Kazuya Saikawa, Fuyuhiko InagakiAbstract:The phagocyte NADPH oxidase plays a crucial role in host defense against microbial infections by generating reactive oxygen species. It is a multisubunit enzyme composed of membrane-bound flavocytochrome b558 as well as cytosolic components, including p47phox, which is essential for assembly of the complex. When phagocytes are activated, the cytosolic components of the NADPH oxidase translocate to flavocytochrome b558 due to binding of the tandem Src homology 3 (SH3) domains of p47phox to a proline-rich region in P22phox, a subunit of flavocytochrome b558. Using NMR titration, we first identified the proline-rich region of P22phox that is essential for binding to the tandem SH3 domains of p47phox. We subsequently determined the solution structure of the p47phox tandem SH3 domains complexed with the proline-rich peptide of P22phox using NMR spectroscopy. In contrast to the intertwined dimer reported for the crystal state, the solution structure is a monomer. The central region of the P22phox peptide forms a polyproline type II helix that is sandwiched by the N- and C-terminal SH3 domains, as was observed in the crystal structure, whereas the C-terminal region of the peptide takes on a short alpha-helical conformation that provides an additional binding site with the N-terminal SH3 domain. Thus, the C-terminal alpha-helical region of the P22phox peptide increases the binding affinity for the tandem SH3 domains of p47phox more than 10-fold.
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The NADPH Oxidase Nox3 Constitutively Produces Superoxide in a P22phox-dependent Manner ITS REGULATION BY OXIDASE ORGANIZERS AND ACTIVATORS
The Journal of biological chemistry, 2005Co-Authors: Noriko Ueno, Ryu Takeya, Kei Miyano, Hideaki Kikuchi, Hideki SumimotoAbstract:Nox3, a member of the superoxide-producing NADPH oxidase (Nox) family, participates in otoconia formation in mouse inner ears, which is required for perception of balance and gravity. The activity of other Nox enzymes such as gp91phox/Nox2 and Nox1 is known to absolutely require both an organizer protein (p47phox or Noxo1) andanactivatorprotein (p67phox or Noxa1); for the p47phox-dependent activation of these oxidases, treatment of cells with stimulants such as phorbol 12-myristate 13-acetate is also indispensable. Here we show that ectopic expression of Nox3 in various types of cells leads to phorbol 12-myristate 13-acetate-independent constitutive production of a substantial amount of superoxide under the conditions where gp91phox and Nox1 fail to generate superoxide, i.e. in the absence of the oxidase organizers and activators. Nox3 likely forms a functional complex with P22phox; Nox3 physically interacts with and stabilizes P22phox, and the Nox3-dependent superoxide production is totally dependent on P22phox. The organizers p47phox and Noxo1 are capable of enhancing the superoxide production by Nox3 in the absence of the activators, and the enhancement requires the interaction of the organizers with P22phox, further indicating a link between Nox3 and P22phox. The p47phox-enhanced Nox3 activity is further facilitated by p67phox or Noxa1, whereas the activators cancel the Noxo1-induced enhancement. On the other hand, the small GTPase Rac, essential for the gp91phox activity, is likely dispensable to the Nox3 system. Thus Nox3 functions together with P22phox as an enzyme constitutively producing superoxide, which can be distinctly regulated by combinatorial use of the organizers and activators.
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assembly and activation of the phagocyte nadph oxidase specific interaction of the n terminal src homology 3 domain of p47phox with P22phox is required for activation of the nadph oxidase
Journal of Biological Chemistry, 1996Co-Authors: Hideki Sumimoto, Kenichiro Hata, Kazuhito Mizuki, Takashi Ito, Yohko Kage, Yoshiyuki Sakaki, Yasuyuki Fukumaki, Michio Nakamura, Koichiro TakeshigeAbstract:Abstract The phagocyte NADPH oxidase is activated during phagocytosis to produce superoxide, a precursor of microbicidal oxidants. The activation involves assembly of membrane-integrated cytochrome b558 comprising gp91phox and P22phox, two specialized cytosolic proteins (p47phox and p67phox), each containing two Src homology 3 (SH3) domains, and the small G protein Rac. In the present study, we show that the N-terminal SH3 domain of p47phox binds to the C-terminal cytoplasmic tail of P22phox with high affinity (KD = 0.34 μM). The binding is specific to this domain among several SH3 domains including the C-terminal one of p47phox and the two of p67phox and requires the Pro156-containing proline-rich sequence but not other putative SH3 domain-binding sites of P22phox. Replacement of Trp193 by Arg in the N-terminal SH3 domain completely abrogates the association with P22phox. A mutant p47phox with this substitution is incapable of supporting superoxide production under cell-free activation conditions. These findings provide direct evidence that the interaction between the N-terminal SH3 domain of p47phox and the proline-rich region of P22phox is essential for activation of the NADPH oxidase.
Nobukazu Ishizaka - One of the best experts on this subject based on the ideXlab platform.
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tumour necrosis factor alpha activates a P22phox based nadh oxidase in vascular smooth muscle
Biochemical Journal, 1998Co-Authors: Gilles W De Keulenaer, Nobukazu Ishizaka, Masuko Ushiofukai, Wayne R Alexander, Kathy K. GriendlingAbstract:Increasing experimental evidence suggests that non-phagocytic cells express a potent superoxide (O2-.)-producing NADH oxidase that might be related to the phagocytic NADPH oxidase. Here we show that the cytokine tumour necrosis factor alpha (TNF-alpha) activates, in a time- and dose-dependent manner, a O2-.-producing NADH oxidase in cultured rat aortic smooth-muscle cells. Dose-response experiments for NADH showed an upward shift of the curve for TNF-alpha-treated cells, suggesting that TNF-alpha increased the amount of available enzyme. Using the anti-sense transfection technique, we further demonstrate that the molecular identity of this oxidase includes p22(phox) (the alpha subunit of cytochrome b558 and part of the electron transfer component of the phagocytic NADPH oxidase), which we recently cloned from a rat vascular smooth-muscle cell cDNA library. In addition, prolonged treatment with TNF-alpha increased P22phox mRNA expression without affecting P22phox mRNA stability, and only when transcriptional activity was intact. These findings identify a P22phox-containing NADH oxidase as a source for cytokine-induced free radical production in vascular smooth-muscle cells and clarify some of the mechanisms involved in the regulation of vascular oxidase activity.
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P22phox mRNA Expression and NADPH Oxidase Activity Are Increased in Aortas From Hypertensive Rats
Circulation research, 1997Co-Authors: Toshiki Fukui, Nobukazu Ishizaka, Sanjay Rajagopalan, Jørn Bech Laursen, Quinn Capers, W. Robert Taylor, David G. Harrison, Hector De Leon, Josiah N. Wilcox, Kathy K. GriendlingAbstract:Recent studies suggest that superoxide production by the NADPH/NADH oxidase may be involved in smooth muscle cell growth and the pathogenesis of hypertension. We previously showed that angiotensin II (Ang II) activates a P22phox-based NADPH/NADH oxidase in cultured rat vascular smooth muscle cells and in animals made hypertensive by infusion of Ang II. To investigate the mechanism responsible for this increased oxidase activity, we examined P22phox mRNA expression in rats made hypertensive by implanting an osmotic minipump that delivered Ang II (0.7 mg/kg per day). Blood pressure began to increase 3 days after the start of Ang II infusion and remained elevated for up to 14 days. Expression of P22phox mRNA in aorta was also increased after 3 days and reached a maximum increase of 338±41% by 5 days after pump implantation compared with the value after sham operation. This increase in mRNA expression was accompanied by an increase in the content of the corresponding cytochrome (twofold) and NADPH oxidase activity (179±11% of that in sham-operated rats 5 days after pump implantation). Treatment with the antihypertensive agents losartan (25 mg/kg per day) or hydralazine (15 mg/kg per day) inhibited this upregulation of mRNA levels and activity. Furthermore, infusion of recombinant heparin-binding superoxide dismutase decreased both blood pressure and P22phox mRNA expression. In situ hybridization of aortic tissue showed that P22phox mRNA was expressed in medial smooth muscle as well as in the adventitia. These findings suggest that Ang II–induced hypertension activates the NADPH/NADH oxidase system by upregulating mRNA levels of one or several components of this oxidase system, including the P22phox, and that the NADPH/NADH oxidase system is associated with the pathology of hypertension in vivo.
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P22phox is a critical component of the superoxide generating nadh nadph oxidase system and regulates angiotensin ii induced hypertrophy in vascular smooth muscle cells
Journal of Biological Chemistry, 1996Co-Authors: Masuko Ushiofukai, Maziar A Zafari, Toshiki Fukui, Nobukazu Ishizaka, Kathy K. GriendlingAbstract:Abstract Superoxide anion formation is vital to the microbicidal activity of phagocytes. Recently, however, there is accumulating evidence that it is also involved in cell growth in vascular smooth muscle cells (VSMCs). We have shown that the hypertrophic agent angiotensin II stimulates superoxide production by activating the membrane-bound NADH/NADPH oxidase and that inhibition of this oxidase attenuates vascular hypertrophy. However, the molecular identity of this oxidase in VSMCs is unknown. We have recently cloned the cytochrome b558 α-subunit, P22phox (one of the key electron transfer elements of the NADPH oxidase in phagocytes), from a rat VSMC cDNA library, but its role in VSMC oxidase activity remains unclarified. Here we report that the complete inhibition of P22phox mRNA expression by stable transfection of antisense P22phox cDNA into VSMCs results in a decrease in cytochrome b content, which is accompanied by a significant inhibition of angiotensin II-stimulated NADH/NADPH-dependent superoxide production, subsequent hydrogen peroxide production, and [3H]leucine incorporation. We provide the first evidence that P22phox is a critical component of superoxide-generating vascular NADH/NADPH oxidase and suggest a central role for this oxidase system in vascular hypertrophy.
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P22phox Is a Critical Component of the Superoxide-generating NADH/NADPH Oxidase System and Regulates Angiotensin IIinduced Hypertrophy in Vascular Smooth Muscle Cells
The Journal of biological chemistry, 1996Co-Authors: Masuko Ushio-fukai, Nobukazu Ishizaka, Toshiki Fukui, A. Maziar Zafari, Kathy K. GriendlingAbstract:Superoxide anion formation is vital to the microbicidal activity of phagocytes. Recently, however, there is accumulating evidence that it is also involved in cell growth in vascular smooth muscle cells (VSMCs). We have shown that the hypertrophic agent angiotensin II stimulates superoxide production by activating the membrane-bound NADH/NADPH oxidase and that inhibition of this oxidase attenuates vascular hypertrophy. However, the molecular identity of this oxidase in VSMCs is unknown. We have recently cloned the cytochrome b558α-subunit, P22phox (one of the key electron transfer elements of the NADPH oxidase in phagocytes), from a rat VSMC cDNA library, but its role in VSMC oxidase activity remains unclarified. Here we report that the complete inhibition of P22phox mRNA expression by stable transfection of antisense P22phox cDNA into VSMCs results in a decrease in cytochrome b content, which is accompanied by a significant inhibition of angiotensin II-stimulated NADH/NADPH-dependent superoxide production, subsequent hydrogen peroxide production, and [3H]leucine incorporation. We provide the first evidence that P22phox is a critical component of superoxide-generating vascular NADH/NADPH oxidase and suggest a central role for this oxidase system in vascular hypertrophy.
Toshiki Fukui - One of the best experts on this subject based on the ideXlab platform.
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P22phox mRNA Expression and NADPH Oxidase Activity Are Increased in Aortas From Hypertensive Rats
Circulation research, 1997Co-Authors: Toshiki Fukui, Nobukazu Ishizaka, Sanjay Rajagopalan, Jørn Bech Laursen, Quinn Capers, W. Robert Taylor, David G. Harrison, Hector De Leon, Josiah N. Wilcox, Kathy K. GriendlingAbstract:Recent studies suggest that superoxide production by the NADPH/NADH oxidase may be involved in smooth muscle cell growth and the pathogenesis of hypertension. We previously showed that angiotensin II (Ang II) activates a P22phox-based NADPH/NADH oxidase in cultured rat vascular smooth muscle cells and in animals made hypertensive by infusion of Ang II. To investigate the mechanism responsible for this increased oxidase activity, we examined P22phox mRNA expression in rats made hypertensive by implanting an osmotic minipump that delivered Ang II (0.7 mg/kg per day). Blood pressure began to increase 3 days after the start of Ang II infusion and remained elevated for up to 14 days. Expression of P22phox mRNA in aorta was also increased after 3 days and reached a maximum increase of 338±41% by 5 days after pump implantation compared with the value after sham operation. This increase in mRNA expression was accompanied by an increase in the content of the corresponding cytochrome (twofold) and NADPH oxidase activity (179±11% of that in sham-operated rats 5 days after pump implantation). Treatment with the antihypertensive agents losartan (25 mg/kg per day) or hydralazine (15 mg/kg per day) inhibited this upregulation of mRNA levels and activity. Furthermore, infusion of recombinant heparin-binding superoxide dismutase decreased both blood pressure and P22phox mRNA expression. In situ hybridization of aortic tissue showed that P22phox mRNA was expressed in medial smooth muscle as well as in the adventitia. These findings suggest that Ang II–induced hypertension activates the NADPH/NADH oxidase system by upregulating mRNA levels of one or several components of this oxidase system, including the P22phox, and that the NADPH/NADH oxidase system is associated with the pathology of hypertension in vivo.
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P22phox is a critical component of the superoxide generating nadh nadph oxidase system and regulates angiotensin ii induced hypertrophy in vascular smooth muscle cells
Journal of Biological Chemistry, 1996Co-Authors: Masuko Ushiofukai, Maziar A Zafari, Toshiki Fukui, Nobukazu Ishizaka, Kathy K. GriendlingAbstract:Abstract Superoxide anion formation is vital to the microbicidal activity of phagocytes. Recently, however, there is accumulating evidence that it is also involved in cell growth in vascular smooth muscle cells (VSMCs). We have shown that the hypertrophic agent angiotensin II stimulates superoxide production by activating the membrane-bound NADH/NADPH oxidase and that inhibition of this oxidase attenuates vascular hypertrophy. However, the molecular identity of this oxidase in VSMCs is unknown. We have recently cloned the cytochrome b558 α-subunit, P22phox (one of the key electron transfer elements of the NADPH oxidase in phagocytes), from a rat VSMC cDNA library, but its role in VSMC oxidase activity remains unclarified. Here we report that the complete inhibition of P22phox mRNA expression by stable transfection of antisense P22phox cDNA into VSMCs results in a decrease in cytochrome b content, which is accompanied by a significant inhibition of angiotensin II-stimulated NADH/NADPH-dependent superoxide production, subsequent hydrogen peroxide production, and [3H]leucine incorporation. We provide the first evidence that P22phox is a critical component of superoxide-generating vascular NADH/NADPH oxidase and suggest a central role for this oxidase system in vascular hypertrophy.
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P22phox Is a Critical Component of the Superoxide-generating NADH/NADPH Oxidase System and Regulates Angiotensin IIinduced Hypertrophy in Vascular Smooth Muscle Cells
The Journal of biological chemistry, 1996Co-Authors: Masuko Ushio-fukai, Nobukazu Ishizaka, Toshiki Fukui, A. Maziar Zafari, Kathy K. GriendlingAbstract:Superoxide anion formation is vital to the microbicidal activity of phagocytes. Recently, however, there is accumulating evidence that it is also involved in cell growth in vascular smooth muscle cells (VSMCs). We have shown that the hypertrophic agent angiotensin II stimulates superoxide production by activating the membrane-bound NADH/NADPH oxidase and that inhibition of this oxidase attenuates vascular hypertrophy. However, the molecular identity of this oxidase in VSMCs is unknown. We have recently cloned the cytochrome b558α-subunit, P22phox (one of the key electron transfer elements of the NADPH oxidase in phagocytes), from a rat VSMC cDNA library, but its role in VSMC oxidase activity remains unclarified. Here we report that the complete inhibition of P22phox mRNA expression by stable transfection of antisense P22phox cDNA into VSMCs results in a decrease in cytochrome b content, which is accompanied by a significant inhibition of angiotensin II-stimulated NADH/NADPH-dependent superoxide production, subsequent hydrogen peroxide production, and [3H]leucine incorporation. We provide the first evidence that P22phox is a critical component of superoxide-generating vascular NADH/NADPH oxidase and suggest a central role for this oxidase system in vascular hypertrophy.
Khalid Matrougui - One of the best experts on this subject based on the ideXlab platform.
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enhanced P22phox expression impairs vascular function through p38 and erk1 2 map kinase dependent mechanisms in type 2 diabetic mice
American Journal of Physiology-heart and Circulatory Physiology, 2014Co-Authors: Modar Kassan, Soo-kyoung Choi, María Galán, Young Ho Lee, Mohamed Trebak, Khalid MatrouguiAbstract:Type 2 diabetes is associated with vascular complication. We hypothesized that increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit P22phox expression impairs vascular endo...
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Enhanced P22phox expression impairs vascular function through p38 and ERK1/2 MAP kinase-dependent mechanisms in type 2 diabetic mice
American Journal of Physiology-heart and Circulatory Physiology, 2014Co-Authors: Modar Kassan, Soo-kyoung Choi, María Galán, Young Ho Lee, Mohamed Trebak, Khalid MatrouguiAbstract:Type 2 diabetes is associated with vascular complication. We hypothesized that increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit P22phox expression impairs vascular endo...
