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Julian H. Lombard - One of the best experts on this subject based on the ideXlab platform.
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Role of vascular reactive oxygen species in regulating Cytochrome P450-4A enzyme expression in Dahl salt-sensitive rats.
Microcirculation (New York N.Y. : 1994), 2016Co-Authors: Kathleen M Lukaszewicz, John R. Falck, Mahesh P. Paudyal, Julian H. LombardAbstract:Objective The potential contribution of CYP4A enzymes to endothelial dysfunction in Dahl salt-sensitive (SS) rats was determined by comparison to SS-5BN consomic rats having chromosome 5 carrying CYP4A alleles from the Brown Norway (BN) rat introgressed into the SS genetic background. Methods The following experiments were performed in cerebral arteries from HS-fed SS and SS-5BN rats ± the SOD inhibitor DETC and/or the superoxide scavenger Tempol: 1) endothelial function was determined via video microscopy ± acute addition of the CYP4A inhibitor DDMS or Tempol; 2) vascular oxidative stress was assessed with DHE fluorescence ± acute addition of DDMS, L-NAME, or PEG-SOD; and 3) CYP4A protein levels were compared by Western blotting. Results In DETC-treated SS-5BN and HS-fed SS rats: 1) DDMS or Tempol ameliorated vascular dysfunction 2) DDMS reduced vascular oxidative stress to control levels; 3) Chronic Tempol treatment reduced vascular CYP4A protein expression; and 3) combined treatment with Tempol and L-NAME prevented the reduction in CYP4A protein expression in MCA of HS-fed SS rats. Conclusion The CYP4A pathway plays a role in vascular dysfunction in SS rats and there appears to be a direct role of reduced NO availability due to salt-induced oxidant stress in upregulating CYP4A enzyme expression. This article is protected by copyright. All rights reserved.
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role of the cyp4A 20 hete pathway in vascular dysfunction of the dahl salt sensitive rat
Clinical Science, 2013Co-Authors: Kathleen M Lukaszewicz, Julian H. LombardAbstract:HETE (20-hydroxyeicosatetraenoic acid), a vasoconstrictor metabolite of arachidonic acid formed through the action of CYP4A (Cytochrome P450-4A) in vascular smooth muscle cells, has been implicated in the development of hypertension and vascular dysfunction. There have been a number of reports in human subjects demonstrating an association between elevated urinary excretion of 20-HETE and hypertension, as well as increased 20-HETE production and vascular dysfunction. The Dahl SS (salt-sensitive) rat is a genetic model of salt-sensitive hypertension that exhibits vascular dysfunction, even when maintained on a normal-salt diet and before the development of hypertension. This mini-review highlights our current research on the role of CYP4A and 20-HETE in the vascular dysfunction of the Dahl SS rat. In our studies, the SS rat is compared with the consomic SS-5 BN rat, having chromosome 5 from the salt-resistant Brown Norway rat (carrying all CYP4A genes) introgressed on to the SS genetic background. Our laboratory has demonstrated restoration of normal vascular function in the SS rat with inhibition of the CYP4A/20-HETE pathway, suggesting a direct role for this pathway in the vascular dysfunction in this animal model. Our studies have also shown that the SS rat has an up-regulated CYP4A/20-HETE pathway within their cerebral vasculature compared with the SS-5 BN consomic rat, which causes endothelial dysfunction through the production of ROS (reactive oxygen species). Our data shows that ROS influences the expression of the CYP4A/20-HETE pathway in the SS rat in a feed-forward mechanism whereby elevated ROS stimulates production of 20-HETE. The presence of this vicious cycle offers a possible explanation for the spiralling effects of elevated 20-HETE on the development of vascular dysfunction in this animal model.
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Role of the CYP4A/20-HETE pathway in vascular dysfunction of the Dahl salt-sensitive rat
Clinical science (London England : 1979), 2013Co-Authors: Kathleen M Lukaszewicz, Julian H. LombardAbstract:HETE (20-hydroxyeicosatetraenoic acid), a vasoconstrictor metabolite of arachidonic acid formed through the action of CYP4A (Cytochrome P450-4A) in vascular smooth muscle cells, has been implicated in the development of hypertension and vascular dysfunction. There have been a number of reports in human subjects demonstrating an association between elevated urinary excretion of 20-HETE and hypertension, as well as increased 20-HETE production and vascular dysfunction. The Dahl SS (salt-sensitive) rat is a genetic model of salt-sensitive hypertension that exhibits vascular dysfunction, even when maintained on a normal-salt diet and before the development of hypertension. This mini-review highlights our current research on the role of CYP4A and 20-HETE in the vascular dysfunction of the Dahl SS rat. In our studies, the SS rat is compared with the consomic SS-5 BN rat, having chromosome 5 from the salt-resistant Brown Norway rat (carrying all CYP4A genes) introgressed on to the SS genetic background. Our laboratory has demonstrated restoration of normal vascular function in the SS rat with inhibition of the CYP4A/20-HETE pathway, suggesting a direct role for this pathway in the vascular dysfunction in this animal model. Our studies have also shown that the SS rat has an up-regulated CYP4A/20-HETE pathway within their cerebral vasculature compared with the SS-5 BN consomic rat, which causes endothelial dysfunction through the production of ROS (reactive oxygen species). Our data shows that ROS influences the expression of the CYP4A/20-HETE pathway in the SS rat in a feed-forward mechanism whereby elevated ROS stimulates production of 20-HETE. The presence of this vicious cycle offers a possible explanation for the spiralling effects of elevated 20-HETE on the development of vascular dysfunction in this animal model.
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modulation by Cytochrome P450 4A ω hydroxylase enzymes of adrenergic vasoconstriction and response to reduced po2 in mesenteric resistance arteries of dahl salt sensitive rats
Microcirculation, 2010Co-Authors: Jingli Wang, Richard J Roman, John R. Falck, Gábor Raffai, Siddam Anjaiah, Brian D. Weinberg, Julian H. LombardAbstract:Please cite this paper as: Raffai, Wang, Roman, Anjaiah, Weinberg, Falck and Lombard (2010). Modulation by Cytochrome P450-4A ω-Hydroxylase Enzymes of Adrenergic Vasoconstriction and Response to Reduced PO2 in Mesenteric Resistance Arteries of Dahl Salt-Sensitive Rats. Microcirculation17(7), 525–535. Abstract Objective: This study evaluated the contribution of the 20-HETE/Cytochrome P450-4A ω-hydroxylase (CYP4A) system to the early development of salt-induced vascular changes in Dahl salt-sensitive (SS) rats. Methods: CYP4A expression and 20-HETE production were evaluated and responses to norepinephrine, endothelin, and reduced PO2 were determined by video microscopy in isolated mesenteric resistance arteries from SS rats fed high salt (HS; 4% NaCl) diet for three days vs. low salt (LS; 0.4% NaCl) controls. Results: CYP4A enzyme inhibition with dibromododecenyl methylsulfimide (DDMS) selectively reduced norepinephrine sensitivity and restored impaired vasodilation in response to reduced PO2 in SS rats fed HS diet. In the presence of DDMS, vasodilatation to reduced PO2 was eliminated by indomethacin and unaffected by l-NAME in rats fed LS diet, and eliminated by l-NAME and unaffected by indomethacin in rats fed HS diet. The 20-HETE agonist WIT003 restored norepinephrine sensitivity in DDMS-treated arteries of HS-fed rats. HS diet increased vascular 20-HETE production and CYP4A protein levels by ∼24% and ∼31%, respectively, although these differences were not significant. Conclusions: These findings support the hypothesis that the 20-HETE/CYP4A system modulates vessel responses to norepinephrine and vascular relaxation to reduced PO2 in mesenteric resistance arteries of SS rats fed HS diet.
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Modulation by Cytochrome P450‐4A ω‐Hydroxylase Enzymes of Adrenergic Vasoconstriction and Response to Reduced PO2 in Mesenteric Resistance Arteries of Dahl Salt‐Sensitive Rats
Microcirculation (New York N.Y. : 1994), 2010Co-Authors: Gábor Raffai, Jingli Wang, Richard J Roman, John R. Falck, Siddam Anjaiah, Brian D. Weinberg, Julian H. LombardAbstract:Please cite this paper as: Raffai, Wang, Roman, Anjaiah, Weinberg, Falck and Lombard (2010). Modulation by Cytochrome P450-4A ω-Hydroxylase Enzymes of Adrenergic Vasoconstriction and Response to Reduced PO2 in Mesenteric Resistance Arteries of Dahl Salt-Sensitive Rats. Microcirculation17(7), 525–535. Abstract Objective: This study evaluated the contribution of the 20-HETE/Cytochrome P450-4A ω-hydroxylase (CYP4A) system to the early development of salt-induced vascular changes in Dahl salt-sensitive (SS) rats. Methods: CYP4A expression and 20-HETE production were evaluated and responses to norepinephrine, endothelin, and reduced PO2 were determined by video microscopy in isolated mesenteric resistance arteries from SS rats fed high salt (HS; 4% NaCl) diet for three days vs. low salt (LS; 0.4% NaCl) controls. Results: CYP4A enzyme inhibition with dibromododecenyl methylsulfimide (DDMS) selectively reduced norepinephrine sensitivity and restored impaired vasodilation in response to reduced PO2 in SS rats fed HS diet. In the presence of DDMS, vasodilatation to reduced PO2 was eliminated by indomethacin and unaffected by l-NAME in rats fed LS diet, and eliminated by l-NAME and unaffected by indomethacin in rats fed HS diet. The 20-HETE agonist WIT003 restored norepinephrine sensitivity in DDMS-treated arteries of HS-fed rats. HS diet increased vascular 20-HETE production and CYP4A protein levels by ∼24% and ∼31%, respectively, although these differences were not significant. Conclusions: These findings support the hypothesis that the 20-HETE/CYP4A system modulates vessel responses to norepinephrine and vascular relaxation to reduced PO2 in mesenteric resistance arteries of SS rats fed HS diet.
John R. Falck - One of the best experts on this subject based on the ideXlab platform.
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Role of vascular reactive oxygen species in regulating Cytochrome P450-4A enzyme expression in Dahl salt-sensitive rats.
Microcirculation (New York N.Y. : 1994), 2016Co-Authors: Kathleen M Lukaszewicz, John R. Falck, Mahesh P. Paudyal, Julian H. LombardAbstract:Objective The potential contribution of CYP4A enzymes to endothelial dysfunction in Dahl salt-sensitive (SS) rats was determined by comparison to SS-5BN consomic rats having chromosome 5 carrying CYP4A alleles from the Brown Norway (BN) rat introgressed into the SS genetic background. Methods The following experiments were performed in cerebral arteries from HS-fed SS and SS-5BN rats ± the SOD inhibitor DETC and/or the superoxide scavenger Tempol: 1) endothelial function was determined via video microscopy ± acute addition of the CYP4A inhibitor DDMS or Tempol; 2) vascular oxidative stress was assessed with DHE fluorescence ± acute addition of DDMS, L-NAME, or PEG-SOD; and 3) CYP4A protein levels were compared by Western blotting. Results In DETC-treated SS-5BN and HS-fed SS rats: 1) DDMS or Tempol ameliorated vascular dysfunction 2) DDMS reduced vascular oxidative stress to control levels; 3) Chronic Tempol treatment reduced vascular CYP4A protein expression; and 3) combined treatment with Tempol and L-NAME prevented the reduction in CYP4A protein expression in MCA of HS-fed SS rats. Conclusion The CYP4A pathway plays a role in vascular dysfunction in SS rats and there appears to be a direct role of reduced NO availability due to salt-induced oxidant stress in upregulating CYP4A enzyme expression. This article is protected by copyright. All rights reserved.
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20-HETE Regulates the Angiogenic Functions of Human Endothelial Progenitor Cells and Contributes to Angiogenesis In Vivo
The Journal of pharmacology and experimental therapeutics, 2014Co-Authors: Li Chen, John R. Falck, Ali S Arbab, A. Guillermo Scicli, Rachel Ackerman, Katherine H. Gotlinger, Mohamed Saleh, Michael Kessler, Lawrence G Mendelowitz, Michal L SchwartzmanAbstract:Circulating endothelial progenitor cells (EPC) contribute to postnatal neovascularization. We identified the Cytochrome P450 4A/F–20-hydroxyeicosatetraenoic acid (CYP4A/F–20-HETE) system as a novel regulator of EPC functions associated with angiogenesis in vitro. Here, we explored cellular mechanisms by which 20-HETE regulates EPC angiogenic functions and assessed its contribution to EPC-mediated angiogenesis in vivo. Results showed that both hypoxia and vascular endothelial growth factor (VEGF) induce CYP4A11 gene and protein expression (the predominant 20-HETE synthases in human EPC), and this is accompanied by an increase in 20-HETE production by ∼1.4- and 1.8-fold, respectively, compared with the control levels. Additional studies demonstrated that 20-HETE and VEGF have a synergistic effect on EPC proliferation, whereas 20-HETE antagonist 20-HEDGE or VEGF-neutralizing antibody negated 20-HETE- or VEGF-induced proliferation, respectively. These findings are consistent with the presence of a positive feedback regulation on EPC proliferation between the 20-HETE and the VEGF pathways. Furthermore, we found that 20-HETE induced EPC adhesion to fibronectin and endothelial cell monolayer by 40 ± 5.6 and 67 ± 10%, respectively, which was accompanied by a rapid induction of very late antigen-4 and chemokine receptor type 4 mRNA and protein expression. Basal and 20-HETE-stimulated increases in adhesion were negated by the inhibition of the CYP4A–20-HETE system. Lastly, EPC increased angiogenesis in vivo by 3.6 ± 0.2-fold using the Matrigel plug angiogenesis assay, and these increases were markedly reduced by the local inhibition of 20-HETE system. These results strengthened the notion that 20-HETE regulates the angiogenic functions of EPC in vitro and EPC-mediated angiogenesis in vivo.
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the Cytochrome P450 4A f 20 hydroxyeicosatetraenoic acid system a regulator of endothelial precursor cells derived from human umbilical cord blood
Journal of Pharmacology and Experimental Therapeutics, 2011Co-Authors: Richard J Roman, John R. Falck, Austin M Guo, Branislava Janic, Ju Sheng, Paul A Edwards, Ali S Arbab, Guillermo A ScicliAbstract:Endothelial progenitor cells (EPCs) contribute to physiological and pathological neovascularization. Previous data have suggested that the Cytochrome P450 4A/F (CYP4A/F)-20-hydroxyeicosatetraenoic acid (20-HETE) system regulates neovascularization. Therefore, we studied whether the angiogenic effects of the CYP4A/F-20-HETE system involve regulation of EPC function. We extracted human umbilical cord blood and isolated EPCs, which express AC133+CD34+ and kinase insert domain receptor (KDR) surface markers and contain mRNA and protein for CYP4A11 and CYP4A22 enzymes, as opposed to mesenchymal stem cells, which only express negligible amounts of CYP4A11/22. When EPCs were incubated with arachidonic acid, they produced 20-HETE, which stimulated the cells to proliferate and migrate, as did vascular endothelial growth factor. Incubation with 1 μM N-hydroxy-N′-(4-butyl-2-methylphenyl)formamidine (HET0016), a selective inhibitor of 20-HETE synthesis, reduced the proliferative and migratory effects of vascular endothelial growth factor and also significantly abolished EPC migration mediated by stroma-derived factor-1α, as did (6,15) 20-hydroxyeicosadienoic acid. Coculturing EPCs and endothelial cells on a Matrigel matrix led to tube formation, which in turn was inhibited by both HET0016 and 20-hydroxyeicosadienoic acid. We concluded that the CYP4A/F-20-HETE system is expressed in EPCs and can act as both an autocrine and a paracrine regulatory factor.
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The Cytochrome P450 4A/F-20-Hydroxyeicosatetraenoic Acid System: A Regulator of Endothelial Precursor Cells Derived from Human Umbilical Cord Blood
The Journal of pharmacology and experimental therapeutics, 2011Co-Authors: Austin M Guo, Richard J Roman, John R. Falck, Branislava Janic, Ju Sheng, Paul A Edwards, Ali S Arbab, A. Guillermo ScicliAbstract:Endothelial progenitor cells (EPCs) contribute to physiological and pathological neovascularization. Previous data have suggested that the Cytochrome P450 4A/F (CYP4A/F)-20-hydroxyeicosatetraenoic acid (20-HETE) system regulates neovascularization. Therefore, we studied whether the angiogenic effects of the CYP4A/F-20-HETE system involve regulation of EPC function. We extracted human umbilical cord blood and isolated EPCs, which express AC133+CD34+ and kinase insert domain receptor (KDR) surface markers and contain mRNA and protein for CYP4A11 and CYP4A22 enzymes, as opposed to mesenchymal stem cells, which only express negligible amounts of CYP4A11/22. When EPCs were incubated with arachidonic acid, they produced 20-HETE, which stimulated the cells to proliferate and migrate, as did vascular endothelial growth factor. Incubation with 1 μM N-hydroxy-N′-(4-butyl-2-methylphenyl)formamidine (HET0016), a selective inhibitor of 20-HETE synthesis, reduced the proliferative and migratory effects of vascular endothelial growth factor and also significantly abolished EPC migration mediated by stroma-derived factor-1α, as did (6,15) 20-hydroxyeicosadienoic acid. Coculturing EPCs and endothelial cells on a Matrigel matrix led to tube formation, which in turn was inhibited by both HET0016 and 20-hydroxyeicosadienoic acid. We concluded that the CYP4A/F-20-HETE system is expressed in EPCs and can act as both an autocrine and a paracrine regulatory factor.
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modulation by Cytochrome P450 4A ω hydroxylase enzymes of adrenergic vasoconstriction and response to reduced po2 in mesenteric resistance arteries of dahl salt sensitive rats
Microcirculation, 2010Co-Authors: Jingli Wang, Richard J Roman, John R. Falck, Gábor Raffai, Siddam Anjaiah, Brian D. Weinberg, Julian H. LombardAbstract:Please cite this paper as: Raffai, Wang, Roman, Anjaiah, Weinberg, Falck and Lombard (2010). Modulation by Cytochrome P450-4A ω-Hydroxylase Enzymes of Adrenergic Vasoconstriction and Response to Reduced PO2 in Mesenteric Resistance Arteries of Dahl Salt-Sensitive Rats. Microcirculation17(7), 525–535. Abstract Objective: This study evaluated the contribution of the 20-HETE/Cytochrome P450-4A ω-hydroxylase (CYP4A) system to the early development of salt-induced vascular changes in Dahl salt-sensitive (SS) rats. Methods: CYP4A expression and 20-HETE production were evaluated and responses to norepinephrine, endothelin, and reduced PO2 were determined by video microscopy in isolated mesenteric resistance arteries from SS rats fed high salt (HS; 4% NaCl) diet for three days vs. low salt (LS; 0.4% NaCl) controls. Results: CYP4A enzyme inhibition with dibromododecenyl methylsulfimide (DDMS) selectively reduced norepinephrine sensitivity and restored impaired vasodilation in response to reduced PO2 in SS rats fed HS diet. In the presence of DDMS, vasodilatation to reduced PO2 was eliminated by indomethacin and unaffected by l-NAME in rats fed LS diet, and eliminated by l-NAME and unaffected by indomethacin in rats fed HS diet. The 20-HETE agonist WIT003 restored norepinephrine sensitivity in DDMS-treated arteries of HS-fed rats. HS diet increased vascular 20-HETE production and CYP4A protein levels by ∼24% and ∼31%, respectively, although these differences were not significant. Conclusions: These findings support the hypothesis that the 20-HETE/CYP4A system modulates vessel responses to norepinephrine and vascular relaxation to reduced PO2 in mesenteric resistance arteries of SS rats fed HS diet.
Richard J Roman - One of the best experts on this subject based on the ideXlab platform.
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the Cytochrome P450 4A f 20 hydroxyeicosatetraenoic acid system a regulator of endothelial precursor cells derived from human umbilical cord blood
Journal of Pharmacology and Experimental Therapeutics, 2011Co-Authors: Richard J Roman, John R. Falck, Austin M Guo, Branislava Janic, Ju Sheng, Paul A Edwards, Ali S Arbab, Guillermo A ScicliAbstract:Endothelial progenitor cells (EPCs) contribute to physiological and pathological neovascularization. Previous data have suggested that the Cytochrome P450 4A/F (CYP4A/F)-20-hydroxyeicosatetraenoic acid (20-HETE) system regulates neovascularization. Therefore, we studied whether the angiogenic effects of the CYP4A/F-20-HETE system involve regulation of EPC function. We extracted human umbilical cord blood and isolated EPCs, which express AC133+CD34+ and kinase insert domain receptor (KDR) surface markers and contain mRNA and protein for CYP4A11 and CYP4A22 enzymes, as opposed to mesenchymal stem cells, which only express negligible amounts of CYP4A11/22. When EPCs were incubated with arachidonic acid, they produced 20-HETE, which stimulated the cells to proliferate and migrate, as did vascular endothelial growth factor. Incubation with 1 μM N-hydroxy-N′-(4-butyl-2-methylphenyl)formamidine (HET0016), a selective inhibitor of 20-HETE synthesis, reduced the proliferative and migratory effects of vascular endothelial growth factor and also significantly abolished EPC migration mediated by stroma-derived factor-1α, as did (6,15) 20-hydroxyeicosadienoic acid. Coculturing EPCs and endothelial cells on a Matrigel matrix led to tube formation, which in turn was inhibited by both HET0016 and 20-hydroxyeicosadienoic acid. We concluded that the CYP4A/F-20-HETE system is expressed in EPCs and can act as both an autocrine and a paracrine regulatory factor.
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The Cytochrome P450 4A/F-20-Hydroxyeicosatetraenoic Acid System: A Regulator of Endothelial Precursor Cells Derived from Human Umbilical Cord Blood
The Journal of pharmacology and experimental therapeutics, 2011Co-Authors: Austin M Guo, Richard J Roman, John R. Falck, Branislava Janic, Ju Sheng, Paul A Edwards, Ali S Arbab, A. Guillermo ScicliAbstract:Endothelial progenitor cells (EPCs) contribute to physiological and pathological neovascularization. Previous data have suggested that the Cytochrome P450 4A/F (CYP4A/F)-20-hydroxyeicosatetraenoic acid (20-HETE) system regulates neovascularization. Therefore, we studied whether the angiogenic effects of the CYP4A/F-20-HETE system involve regulation of EPC function. We extracted human umbilical cord blood and isolated EPCs, which express AC133+CD34+ and kinase insert domain receptor (KDR) surface markers and contain mRNA and protein for CYP4A11 and CYP4A22 enzymes, as opposed to mesenchymal stem cells, which only express negligible amounts of CYP4A11/22. When EPCs were incubated with arachidonic acid, they produced 20-HETE, which stimulated the cells to proliferate and migrate, as did vascular endothelial growth factor. Incubation with 1 μM N-hydroxy-N′-(4-butyl-2-methylphenyl)formamidine (HET0016), a selective inhibitor of 20-HETE synthesis, reduced the proliferative and migratory effects of vascular endothelial growth factor and also significantly abolished EPC migration mediated by stroma-derived factor-1α, as did (6,15) 20-hydroxyeicosadienoic acid. Coculturing EPCs and endothelial cells on a Matrigel matrix led to tube formation, which in turn was inhibited by both HET0016 and 20-hydroxyeicosadienoic acid. We concluded that the CYP4A/F-20-HETE system is expressed in EPCs and can act as both an autocrine and a paracrine regulatory factor.
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modulation by Cytochrome P450 4A ω hydroxylase enzymes of adrenergic vasoconstriction and response to reduced po2 in mesenteric resistance arteries of dahl salt sensitive rats
Microcirculation, 2010Co-Authors: Jingli Wang, Richard J Roman, John R. Falck, Gábor Raffai, Siddam Anjaiah, Brian D. Weinberg, Julian H. LombardAbstract:Please cite this paper as: Raffai, Wang, Roman, Anjaiah, Weinberg, Falck and Lombard (2010). Modulation by Cytochrome P450-4A ω-Hydroxylase Enzymes of Adrenergic Vasoconstriction and Response to Reduced PO2 in Mesenteric Resistance Arteries of Dahl Salt-Sensitive Rats. Microcirculation17(7), 525–535. Abstract Objective: This study evaluated the contribution of the 20-HETE/Cytochrome P450-4A ω-hydroxylase (CYP4A) system to the early development of salt-induced vascular changes in Dahl salt-sensitive (SS) rats. Methods: CYP4A expression and 20-HETE production were evaluated and responses to norepinephrine, endothelin, and reduced PO2 were determined by video microscopy in isolated mesenteric resistance arteries from SS rats fed high salt (HS; 4% NaCl) diet for three days vs. low salt (LS; 0.4% NaCl) controls. Results: CYP4A enzyme inhibition with dibromododecenyl methylsulfimide (DDMS) selectively reduced norepinephrine sensitivity and restored impaired vasodilation in response to reduced PO2 in SS rats fed HS diet. In the presence of DDMS, vasodilatation to reduced PO2 was eliminated by indomethacin and unaffected by l-NAME in rats fed LS diet, and eliminated by l-NAME and unaffected by indomethacin in rats fed HS diet. The 20-HETE agonist WIT003 restored norepinephrine sensitivity in DDMS-treated arteries of HS-fed rats. HS diet increased vascular 20-HETE production and CYP4A protein levels by ∼24% and ∼31%, respectively, although these differences were not significant. Conclusions: These findings support the hypothesis that the 20-HETE/CYP4A system modulates vessel responses to norepinephrine and vascular relaxation to reduced PO2 in mesenteric resistance arteries of SS rats fed HS diet.
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Modulation by Cytochrome P450‐4A ω‐Hydroxylase Enzymes of Adrenergic Vasoconstriction and Response to Reduced PO2 in Mesenteric Resistance Arteries of Dahl Salt‐Sensitive Rats
Microcirculation (New York N.Y. : 1994), 2010Co-Authors: Gábor Raffai, Jingli Wang, Richard J Roman, John R. Falck, Siddam Anjaiah, Brian D. Weinberg, Julian H. LombardAbstract:Please cite this paper as: Raffai, Wang, Roman, Anjaiah, Weinberg, Falck and Lombard (2010). Modulation by Cytochrome P450-4A ω-Hydroxylase Enzymes of Adrenergic Vasoconstriction and Response to Reduced PO2 in Mesenteric Resistance Arteries of Dahl Salt-Sensitive Rats. Microcirculation17(7), 525–535. Abstract Objective: This study evaluated the contribution of the 20-HETE/Cytochrome P450-4A ω-hydroxylase (CYP4A) system to the early development of salt-induced vascular changes in Dahl salt-sensitive (SS) rats. Methods: CYP4A expression and 20-HETE production were evaluated and responses to norepinephrine, endothelin, and reduced PO2 were determined by video microscopy in isolated mesenteric resistance arteries from SS rats fed high salt (HS; 4% NaCl) diet for three days vs. low salt (LS; 0.4% NaCl) controls. Results: CYP4A enzyme inhibition with dibromododecenyl methylsulfimide (DDMS) selectively reduced norepinephrine sensitivity and restored impaired vasodilation in response to reduced PO2 in SS rats fed HS diet. In the presence of DDMS, vasodilatation to reduced PO2 was eliminated by indomethacin and unaffected by l-NAME in rats fed LS diet, and eliminated by l-NAME and unaffected by indomethacin in rats fed HS diet. The 20-HETE agonist WIT003 restored norepinephrine sensitivity in DDMS-treated arteries of HS-fed rats. HS diet increased vascular 20-HETE production and CYP4A protein levels by ∼24% and ∼31%, respectively, although these differences were not significant. Conclusions: These findings support the hypothesis that the 20-HETE/CYP4A system modulates vessel responses to norepinephrine and vascular relaxation to reduced PO2 in mesenteric resistance arteries of SS rats fed HS diet.
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Modulation of Vascular O2 Responses by Cytochrome 450-4A ω-Hydroxylase Metabolites In Dahl Salt-Sensitive Rats
Microcirculation (New York N.Y. : 1994), 2009Co-Authors: Jingli Wang, Richard J Roman, John R. Falck, Siddam Anjaiah, James R. Schmidt, Julian H. LombardAbstract:Objective: This study evaluated the role of the 20-HETE/Cytochrome P450-4A ω-hydroxylase (CYP450-4A) system in microvascular regulation in the skeletal muscle circulation following short-term (three-day) exposure to a high-salt (HS) diet in Dahl salt-sensitive (SS) rats.Methods: The effects of inhibiting CYP450-4A on resting diameter, O2-induced constriction, and vasodilator responses to acetylcholine (ACh) and the nitric oxide (NO) donor, sodium nitroprusside (SNP), were evaluated in cremasteric arterioles of SS rats fed a low- (LS; 0.4% NaCl) or high-salt (HS; 4% NaCl) diet for three days.Results: The HS diet upregulated CYP450-4A mRNA expression and led to an enhanced constriction of arterioles in response to elevated PO2 in SS rats, which could be blocked by inhibiting CYP450-4A enzymes with dibromododecenyl methylsulfimide (DDMS). DDMS also inhibited resting tone significantly in SS rats fed the HS, but not the LS, diet, despite similar resting diameters and active tone in the two groups. Arteriolar ...
Austin M Guo - One of the best experts on this subject based on the ideXlab platform.
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20-HETE in neovascularization
Prostaglandins & other lipid mediators, 2011Co-Authors: Li Chen, Rachel Ackerman, Austin M GuoAbstract:Cytochrome P450 4A/F (CYP4A/F) converts arachidonic acid (AA) to 20-HETE by ω-hydroxylation. The contribution of 20-HETE to the regulation of myogenic response, blood pressure, and mitogenic actions has been well summarized. This review focuses on the emerging role of 20-HETE in physiological and pathological vascularization. 20-HETE has been shown to regulate vascular smooth muscle cells (VSMC) and endothelial cells (EC) by affecting their proliferation, migration, survival, and tube formation. Furthermore, the proliferation, migration, secretion of proangiogenic molecules (such as HIF-1α, VEGF, SDF-1α), and tube formation of endothelial progenitor cells (EPC) are stimulated by 20-HETE. These effects are mediated through c-Src- and EGFR-mediated downstream signaling pathways, including MAPK and PI3K/Akt pathways, eNOS uncoupling, and NOX/ROS system activation. Therefore, the CYP4A/F-20-HETE system may be a therapeutic target for the treatment of abnormal angiogenic diseases.
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the Cytochrome P450 4A f 20 hydroxyeicosatetraenoic acid system a regulator of endothelial precursor cells derived from human umbilical cord blood
Journal of Pharmacology and Experimental Therapeutics, 2011Co-Authors: Richard J Roman, John R. Falck, Austin M Guo, Branislava Janic, Ju Sheng, Paul A Edwards, Ali S Arbab, Guillermo A ScicliAbstract:Endothelial progenitor cells (EPCs) contribute to physiological and pathological neovascularization. Previous data have suggested that the Cytochrome P450 4A/F (CYP4A/F)-20-hydroxyeicosatetraenoic acid (20-HETE) system regulates neovascularization. Therefore, we studied whether the angiogenic effects of the CYP4A/F-20-HETE system involve regulation of EPC function. We extracted human umbilical cord blood and isolated EPCs, which express AC133+CD34+ and kinase insert domain receptor (KDR) surface markers and contain mRNA and protein for CYP4A11 and CYP4A22 enzymes, as opposed to mesenchymal stem cells, which only express negligible amounts of CYP4A11/22. When EPCs were incubated with arachidonic acid, they produced 20-HETE, which stimulated the cells to proliferate and migrate, as did vascular endothelial growth factor. Incubation with 1 μM N-hydroxy-N′-(4-butyl-2-methylphenyl)formamidine (HET0016), a selective inhibitor of 20-HETE synthesis, reduced the proliferative and migratory effects of vascular endothelial growth factor and also significantly abolished EPC migration mediated by stroma-derived factor-1α, as did (6,15) 20-hydroxyeicosadienoic acid. Coculturing EPCs and endothelial cells on a Matrigel matrix led to tube formation, which in turn was inhibited by both HET0016 and 20-hydroxyeicosadienoic acid. We concluded that the CYP4A/F-20-HETE system is expressed in EPCs and can act as both an autocrine and a paracrine regulatory factor.
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The Cytochrome P450 4A/F-20-Hydroxyeicosatetraenoic Acid System: A Regulator of Endothelial Precursor Cells Derived from Human Umbilical Cord Blood
The Journal of pharmacology and experimental therapeutics, 2011Co-Authors: Austin M Guo, Richard J Roman, John R. Falck, Branislava Janic, Ju Sheng, Paul A Edwards, Ali S Arbab, A. Guillermo ScicliAbstract:Endothelial progenitor cells (EPCs) contribute to physiological and pathological neovascularization. Previous data have suggested that the Cytochrome P450 4A/F (CYP4A/F)-20-hydroxyeicosatetraenoic acid (20-HETE) system regulates neovascularization. Therefore, we studied whether the angiogenic effects of the CYP4A/F-20-HETE system involve regulation of EPC function. We extracted human umbilical cord blood and isolated EPCs, which express AC133+CD34+ and kinase insert domain receptor (KDR) surface markers and contain mRNA and protein for CYP4A11 and CYP4A22 enzymes, as opposed to mesenchymal stem cells, which only express negligible amounts of CYP4A11/22. When EPCs were incubated with arachidonic acid, they produced 20-HETE, which stimulated the cells to proliferate and migrate, as did vascular endothelial growth factor. Incubation with 1 μM N-hydroxy-N′-(4-butyl-2-methylphenyl)formamidine (HET0016), a selective inhibitor of 20-HETE synthesis, reduced the proliferative and migratory effects of vascular endothelial growth factor and also significantly abolished EPC migration mediated by stroma-derived factor-1α, as did (6,15) 20-hydroxyeicosadienoic acid. Coculturing EPCs and endothelial cells on a Matrigel matrix led to tube formation, which in turn was inhibited by both HET0016 and 20-hydroxyeicosadienoic acid. We concluded that the CYP4A/F-20-HETE system is expressed in EPCs and can act as both an autocrine and a paracrine regulatory factor.
A. Guillermo Scicli - One of the best experts on this subject based on the ideXlab platform.
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20-HETE Regulates the Angiogenic Functions of Human Endothelial Progenitor Cells and Contributes to Angiogenesis In Vivo
The Journal of pharmacology and experimental therapeutics, 2014Co-Authors: Li Chen, John R. Falck, Ali S Arbab, A. Guillermo Scicli, Rachel Ackerman, Katherine H. Gotlinger, Mohamed Saleh, Michael Kessler, Lawrence G Mendelowitz, Michal L SchwartzmanAbstract:Circulating endothelial progenitor cells (EPC) contribute to postnatal neovascularization. We identified the Cytochrome P450 4A/F–20-hydroxyeicosatetraenoic acid (CYP4A/F–20-HETE) system as a novel regulator of EPC functions associated with angiogenesis in vitro. Here, we explored cellular mechanisms by which 20-HETE regulates EPC angiogenic functions and assessed its contribution to EPC-mediated angiogenesis in vivo. Results showed that both hypoxia and vascular endothelial growth factor (VEGF) induce CYP4A11 gene and protein expression (the predominant 20-HETE synthases in human EPC), and this is accompanied by an increase in 20-HETE production by ∼1.4- and 1.8-fold, respectively, compared with the control levels. Additional studies demonstrated that 20-HETE and VEGF have a synergistic effect on EPC proliferation, whereas 20-HETE antagonist 20-HEDGE or VEGF-neutralizing antibody negated 20-HETE- or VEGF-induced proliferation, respectively. These findings are consistent with the presence of a positive feedback regulation on EPC proliferation between the 20-HETE and the VEGF pathways. Furthermore, we found that 20-HETE induced EPC adhesion to fibronectin and endothelial cell monolayer by 40 ± 5.6 and 67 ± 10%, respectively, which was accompanied by a rapid induction of very late antigen-4 and chemokine receptor type 4 mRNA and protein expression. Basal and 20-HETE-stimulated increases in adhesion were negated by the inhibition of the CYP4A–20-HETE system. Lastly, EPC increased angiogenesis in vivo by 3.6 ± 0.2-fold using the Matrigel plug angiogenesis assay, and these increases were markedly reduced by the local inhibition of 20-HETE system. These results strengthened the notion that 20-HETE regulates the angiogenic functions of EPC in vitro and EPC-mediated angiogenesis in vivo.
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The Cytochrome P450 4A/F-20-Hydroxyeicosatetraenoic Acid System: A Regulator of Endothelial Precursor Cells Derived from Human Umbilical Cord Blood
The Journal of pharmacology and experimental therapeutics, 2011Co-Authors: Austin M Guo, Richard J Roman, John R. Falck, Branislava Janic, Ju Sheng, Paul A Edwards, Ali S Arbab, A. Guillermo ScicliAbstract:Endothelial progenitor cells (EPCs) contribute to physiological and pathological neovascularization. Previous data have suggested that the Cytochrome P450 4A/F (CYP4A/F)-20-hydroxyeicosatetraenoic acid (20-HETE) system regulates neovascularization. Therefore, we studied whether the angiogenic effects of the CYP4A/F-20-HETE system involve regulation of EPC function. We extracted human umbilical cord blood and isolated EPCs, which express AC133+CD34+ and kinase insert domain receptor (KDR) surface markers and contain mRNA and protein for CYP4A11 and CYP4A22 enzymes, as opposed to mesenchymal stem cells, which only express negligible amounts of CYP4A11/22. When EPCs were incubated with arachidonic acid, they produced 20-HETE, which stimulated the cells to proliferate and migrate, as did vascular endothelial growth factor. Incubation with 1 μM N-hydroxy-N′-(4-butyl-2-methylphenyl)formamidine (HET0016), a selective inhibitor of 20-HETE synthesis, reduced the proliferative and migratory effects of vascular endothelial growth factor and also significantly abolished EPC migration mediated by stroma-derived factor-1α, as did (6,15) 20-hydroxyeicosadienoic acid. Coculturing EPCs and endothelial cells on a Matrigel matrix led to tube formation, which in turn was inhibited by both HET0016 and 20-hydroxyeicosadienoic acid. We concluded that the CYP4A/F-20-HETE system is expressed in EPCs and can act as both an autocrine and a paracrine regulatory factor.
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Inhibitors of Cytochrome P450 4A suppress angiogenic responses
The American journal of pathology, 2005Co-Authors: Ping Chen, Richard J Roman, John R. Falck, Paul A Edwards, Meng Guo, Dana Wygle, A. Guillermo ScicliAbstract:Cytochrome P450 enzymes of the 4A family (CYP4A) convert arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE) in blood vessels of several vascular beds. The present study examined the effects of inhibiting the formation of 20-HETE with N-hydroxy-N′-(4-butyl-2-methylphenol) formamidine (HET0016) on the mitogenic response of vascular endothelial growth factor (VEGF) in human umbilical vein endothelial cells (HUVECs) in vitro, and on growth factor-induced angiogenesis in the cornea of rats in vivo. HET0016 (10 μmol/L and 20 μg, respectively) abolished the mitogenic response to VEGF in HUVECs and the angiogenic response to VEGF, basic fibroblast growth factor, and epidermal growth factor in vivo by 80 to 90% (P < 0.001). Dibromododecenyl methylsulfonimide (DDMS), a structurally and mechanistically different inhibitor of 20-HETE synthesis, also abolished angiogenic responses when tested with VEGF. Additionally, administration of the stable 20-HETE agonist, 20-hydroxyeicosa-6(Z) 15(Z)-dienoic acid (WIT003) induced mitogenesis in HUVECs and angiogenesis in the rat cornea in vivo. We studied the ability of HET0016 to alter the angiogenic response in the rat cornea to human glioblastoma cancer cells (U251). When administered locally into the cornea, HET0016 (20 μg) reduced the angiogenic response to U251 cancer cells by 70%. These results suggest that a product of CYP4A product, possibly 20-HETE, plays a critical role in the regulation of angiogenesis and may provide a useful target for reduction of pathological angiogenesis.
