Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
Add more filters










Publication year range
1.
Biophys J ; 122(18): 3690-3703, 2023 09 19.
Article in English | MEDLINE | ID: mdl-37254483

ABSTRACT

Fetal lung fibroblasts contribute dynamic infrastructure for the developing lung. These cells undergo dynamic mechanical transitions, including cyclic stretch and spreading, which are integral to lung growth in utero. We investigated the role of the nuclear envelope protein emerin in cellular responses to these dynamic mechanical transitions. In contrast to control cells, which briskly realigned their nuclei, actin cytoskeleton, and extracellular matrices in response to cyclic stretch, fibroblasts that were acutely downregulated for emerin showed incomplete reorientation of both nuclei and actin cytoskeleton. Emerin-downregulated fibroblasts were also aberrantly circular in contrast to the spindle-shaped controls and exhibited an altered pattern of filamentous actin organization that was disconnected from the nucleus. Emerin knockdown was also associated with reduced myosin light chain phosphorylation during cell spreading. Interestingly, emerin-downregulated fibroblasts also demonstrated reduced fibronectin fibrillogenesis and production. These findings indicate that nuclear-cytoskeletal coupling serves a role in the dynamic regulation of cytoskeletal structure and function and may also impact the transmission of traction force to the extracellular matrix microenvironment.


Subject(s)
Actomyosin , Cytoskeleton , Actomyosin/metabolism , Down-Regulation , Cytoskeleton/metabolism , Actin Cytoskeleton/metabolism
2.
Front Physiol ; 12: 675724, 2021.
Article in English | MEDLINE | ID: mdl-34220539

ABSTRACT

We previously reported that histone deacetylase 6 (HDAC6) has an important role in endothelial cell (EC) function in vitro. However, whether HDAC6 plays a role in atherogenesis in vivo and the mechanism(s) that control HDAC6 activity/expression in response to atherogenic stimuli are unclear. The goals of this study were to determine whether HDAC6 inhibitor tubacin attenuates atherogenesis and to elucidate specific molecular mechanism(s) that regulate endothelial HDAC6 expression/activity. We evaluated whether administration of tubacin attenuated or reversed the endothelial dysfunction and atherosclerosis induced in mice by a single intraperitoneal injection of adeno-associated viruses encoding liver-target PCSK9 gain-of-function mutant followed by a high fat diet (HFD) for 18 weeks. Tubacin significantly blunted PCSK9-induced increases in pulse wave velocity (index of vascular stiffness and overall vascular health) that are also seen in atherogenic mice. Furthermore, tubacin protected vessels from defective vasorelaxation, as evaluated by acetylcholine-mediated relaxation using wire myograph. Plaque burden defined by Oil Red O staining was also found to be significantly less in mice that received tubacin than in those that received PCSK9 alone. Inhibition of the NEDDylation pathway with MLN4924, an inhibitor of NEDD8-activating enzyme 1 (NAE1), significantly increased HDAC6 activity in HAECs. Interestingly, HDAC6 expression remained unchanged. Further, HAECs exposed to the atherogenic stimulus oxidized low-density lipoprotein (OxLDL) exhibited enhanced HDAC6 activity, which was attenuated by pretreatment with MLN4924. The HDAC6 NEDDylation molecular pathway might regulate genes related to endothelial control of vasomotor tone, reactivity, and atherosclerosis. Tubacin may represent a novel pharmacologic intervention for atherogenesis and other vasculopathies.

3.
Am J Respir Cell Mol Biol ; 65(3): 300-308, 2021 09.
Article in English | MEDLINE | ID: mdl-34003736

ABSTRACT

Endothelial dysfunction is implicated in the thrombotic events reported in patients with coronavirus disease (COVID-19), but the underlying molecular mechanisms are unknown. Circulating levels of the coagulation cascade activator PAI-1 are substantially higher in patients with COVID-19 with severe respiratory dysfunction than in patients with bacterial sepsis and acute respiratory distress syndrome. Indeed, the elevation of PAI-1 is recognized as an early marker of endothelial dysfunction. Here, we report that the rSARS-CoV-2-S1 (recombinant severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] viral envelope spike) glycoprotein stimulated robust production of PAI-1 by human pulmonary microvascular endothelial cells (HPMECs). We examined the role of protein degradation in this SARS-CoV-2-S1 induction of PAI-1 and found that the proteasomal degradation inhibitor bortezomib inhibited SARS-CoV-2-S1-mediated changes in PAI-1. Our data further show that bortezomib upregulated KLF2, a shear-stress-regulated transcription factor that suppresses PAI-1 expression. Aging and metabolic disorders are known to increase mortality and morbidity in patients with COVID-19. We therefore examined the role of ZMPSTE24 (zinc metallopeptidase STE24), a metalloprotease with a demonstrated role in host defense against RNA viruses that is decreased in older individuals and in metabolic syndrome, in the induction of PAI-1 in HPMECs by SARS-CoV-2-S1. Indeed, overexpression of ZMPSTE24 blunted enhancement of PAI-1 production in spike protein-exposed HPMECs. In addition, we found that membrane expression of the SARS-CoV-2 entry receptor ACE2 was reduced by ZMPSTE24-mediated cleavage and shedding of the ACE2 ectodomain, leading to accumulation of ACE2 decoy fragments that may bind SARS-CoV-2. These data indicate that decreases in ZMPSTE24 with age and comorbidities may increase vulnerability to vascular endothelial injury by SARS-CoV-2 viruses and that enhanced production of endothelial PAI-1 might play role in prothrombotic events in patients with COVID-19.


Subject(s)
COVID-19/virology , Endothelial Cells/pathology , Membrane Proteins/metabolism , Metalloendopeptidases/metabolism , Plasminogen Activator Inhibitor 1/metabolism , Pulmonary Artery/pathology , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/metabolism , Aging , COVID-19/metabolism , Cells, Cultured , Endothelial Cells/metabolism , Endothelial Cells/virology , Humans , Membrane Proteins/genetics , Metalloendopeptidases/genetics , Plasminogen Activator Inhibitor 1/genetics , Proteolysis , Pulmonary Artery/metabolism , Pulmonary Artery/virology , Spike Glycoprotein, Coronavirus/genetics
4.
Cell Physiol Biochem ; 54(5): 947-958, 2020 Sep 26.
Article in English | MEDLINE | ID: mdl-32975918

ABSTRACT

BACKGROUND/AIMS: We recently described a novel regulatory role for histone deacetylase 2 (HDAC2) in protecting endothelial cells from oxidized low-density lipoprotein (OxLDL)-induced injury. In this study, we examined the effects of endothelial-specific HDAC2 overexpression on endothelial-dependent vasorelaxation and atherogenesis in vivo. METHODS: Endothelial-specific HDAC2-overexpressing transgenic mice (HDAC2-Tg) were generated under control of the Tie2 promoter. An atherosclerosis model was produced by injecting HDAC2-Tg and wild-type (WT) mice with adeno-associated virus encoding a PCSK9 gain-of-function mutant under control of a liver-specific promoter and feeding them a high-fat diet for 12 weeks. Aortic stiffness in vivo was determined by measuring pulse wave velocity. Wire myography was used to measure endothelium dependent (acetylcholine) and independent (sodium nitroprusside) relaxation in isolated mice aortas. Atherosclerotic plaque burden in aortas was determined by Oil Red O staining and protein expression was determined by western blotting. RESULTS: At baseline, HDAC2-Tg mice had normal mean arterial blood pressure (MAP) and body weight, but pulse wave velocity (PWV), an inverse measure of vascular health and stiffness, was decreased, suggesting that their vessels were more compliant. Moreover, basal nitric oxide production was enhanced in the vessels of HDAC2-Tg mice as compared to that in WT controls, although no significant differences in acetylcholine (endothelial component)- or sodium nitroprusside (non-endothelial component)-mediated relaxation were observed. However, after exposure to OxLDL, aortas from HDAC2-Tg mice exhibited greater acetylcholine-induced relaxation than did those from WT mice. Thus, endothelial-specific vasodilator production was enhanced despite oxidative injury. Atherosclerosis induction in WT mice led to a significant increase in PWV, but in HDAC2-Tg mice, PWV and MAP remained unchanged. Further, aortic rings from HDAC2-Tg exhibited better endothelial-dependent vascular relaxation than did those from WT mice, but not when treated with nitric oxide synthase inhibitor L-NAME. Finally, plaque burden, determined by Oil red O staining, was significantly increased in WT, but not HDAC2-Tg mice, subjected to the atherogenic model. Deletion of endothelial HDAC2 led to impaired endothelial cell-dependent vascular relaxation and increased PWV, compared with those in littermate controls. CONCLUSION: HDAC2 protects against endothelial dysfunction and atherogenesis induced by oxidized lipids. Hence, overexpression or activation of HDAC2 represents a novel therapy for endothelial dysfunction and atherosclerosis. HDAC2-Tg mice provide an opportunity to determine the role of endothelial HDAC2 in vascular endothelial homeostasis.


Subject(s)
Atherosclerosis/enzymology , Histone Deacetylase 2/biosynthesis , Animals , Aorta/metabolism , Apolipoproteins E/genetics , Apolipoproteins E/metabolism , Atherosclerosis/metabolism , Atherosclerosis/pathology , Endothelial Cells/enzymology , Endothelial Cells/metabolism , Endothelium/enzymology , Endothelium/metabolism , Endothelium, Vascular/metabolism , HEK293 Cells , Histone Deacetylase 2/genetics , Histone Deacetylase 2/metabolism , Humans , Lipoproteins, LDL , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Nitric Oxide/metabolism , Plaque, Atherosclerotic/metabolism , Proprotein Convertase 9/metabolism , Pulse Wave Analysis , Vasodilation/drug effects , Vasodilator Agents/pharmacology
5.
Pharmacol Res ; 146: 104281, 2019 08.
Article in English | MEDLINE | ID: mdl-31125601

ABSTRACT

Cystathionine γ-lyase (CSEγ) is a hydrogen sulfide (H2S)-producing enzyme. Endothelial H2S production can mediate vasodilatory effects, contributing to the alleviation of hypertension (high blood pressure). Recent studies have suggested a role of histone deacetylase 6 (HDAC6) in hypertension, although its underlying mechanisms are poorly understood. Here, we addressed the potential regulation of CSEγ by HDAC6 in angiotensin II (AngII)-induced hypertension and its molecular details focusing on CSEγ posttranslational modification. Treatment of mice with a selective HDAC6 inhibitor tubastatin A (TubA) alleviated high blood pressure and vasoconstriction induced by AngII. Cotreatment of the aorta and human aortic endothelial cells with TubA recovered AngII-mediated decreased H2S levels. AngII treatment upregulated HDAC6 mRNA and protein expression, but conversely downregulated CSEγ protein. Notably, potent HDAC6 inhibitors and HDAC6 siRNA as well as a proteasomal inhibitor increased CSEγ protein levels and blocked the downregulatory effect of AngII on CSEγ. In contrast, other HDAC isoforms-specific inhibitors and siRNAs did not show such blocking effects. Transfected CSEγ protein levels were also reciprocally regulated by AngII and TubA, and were reduced by wild-type, but not by deacetylase-deficient, HDAC6. Moreover, TubA significantly increased both protein stability and K73 acetylation level of CSEγ. Consistent with these results, AngII induced CSEγ ubiquitination and degradation, which was inhibited by TubA. Our results indicate that AngII promoted HDAC6-dependent deacetylation of CSEγ at K73 residue, leading to its ubiquitin-mediated proteolysis, which underlies AngII-induced hypertension. Overall, this study suggests that upregulation of CSEγ and H2S through HDAC6 inhibition may be considered as a valid strategy for preventing the progression of hypertension.


Subject(s)
Angiotensin II/pharmacology , Cystathionine gamma-Lyase/metabolism , Histone Deacetylase 6/antagonists & inhibitors , Histone Deacetylase Inhibitors/pharmacology , Hydrogen Sulfide/metabolism , Hydroxamic Acids/pharmacology , Hypertension/metabolism , Indoles/pharmacology , Animals , Aorta/cytology , Endothelial Cells/metabolism , HEK293 Cells , Histone Deacetylase 6/genetics , Histone Deacetylase 6/metabolism , Humans , Hypertension/chemically induced , Hypertension/genetics , Male , Mice, Inbred C57BL , Proteolysis/drug effects
6.
Arterioscler Thromb Vasc Biol ; 38(4): 913-926, 2018 04.
Article in English | MEDLINE | ID: mdl-29472234

ABSTRACT

OBJECTIVE: KLF15 (Kruppel-like factor 15) has recently been shown to suppress activation of proinflammatory processes that contribute to atherogenesis in vascular smooth muscle, however, the role of KLF15 in vascular endothelial function is unknown. Arginase mediates inflammatory vasculopathy and vascular injury in pulmonary hypertension. Here, we tested the hypothesis that KLF15 is a critical regulator of hypoxia-induced Arg2 (arginase 2) transcription in human pulmonary microvascular endothelial cells (HPMEC). APPROACH AND RESULTS: Quiescent HPMEC express ample amounts of full-length KLF15. HPMECs exposed to 24 hours of hypoxia exhibited a marked decrease in KLF15 protein levels and a reciprocal increase in Arg2 protein and mRNA. Chromatin immunoprecipitation indicated direct binding of KLF15 to the Arg2 promoter, which was relieved with HPMEC exposure to hypoxia. Furthermore, overexpression of KLF15 in HPMEC reversed hypoxia-induced augmentation of Arg2 abundance and arginase activity and rescued nitric oxide (NO) production. Ectopic KLF15 also reversed hypoxia-induced endothelium-mediated vasodilatation in isolated rat pulmonary artery rings. Mechanisms by which hypoxia regulates KLF15 abundance, stability, and compartmentalization to the nucleus in HPMEC were then investigated. Hypoxia triggered deSUMOylation of KLF15 by SENP1 (sentrin-specific protease 1), and translocation of KLF15 from nucleus to cytoplasm. CONCLUSIONS: KLF15 is a critical regulator of pulmonary endothelial homeostasis via repression of endothelial Arg2 expression. KLF15 abundance and nuclear compartmentalization are regulated by SUMOylation/deSUMOylation-a hypoxia-sensitive process that is controlled by SENP1. Strategies including overexpression of KLF15 or inhibition of SENP1 may represent novel therapeutic targets for pulmonary hypertension.


Subject(s)
Arginase/metabolism , Cysteine Endopeptidases/metabolism , Endothelial Cells/enzymology , Kruppel-Like Transcription Factors/metabolism , Lung/blood supply , Microvessels/enzymology , Nuclear Proteins/metabolism , Transcription, Genetic , Active Transport, Cell Nucleus , Animals , Arginase/genetics , Cell Hypoxia , Cells, Cultured , Cysteine Endopeptidases/genetics , Endothelial Cells/pathology , Gene Expression Regulation, Enzymologic , Humans , Kruppel-Like Transcription Factors/genetics , Microvessels/pathology , Nitric Oxide/metabolism , Nitric Oxide Synthase Type III/genetics , Nitric Oxide Synthase Type III/metabolism , Nuclear Proteins/genetics , Proteasome Endopeptidase Complex/metabolism , Proteolysis , Pulmonary Artery/metabolism , Pulmonary Artery/physiopathology , Rats , Signal Transduction , Sumoylation , Vasodilation
7.
Am J Physiol Lung Cell Mol Physiol ; 314(1): L93-L106, 2018 01 01.
Article in English | MEDLINE | ID: mdl-28882814

ABSTRACT

We recently demonstrated that blue light induces vasorelaxation in the systemic mouse circulation, a phenomenon mediated by the nonvisual G protein-coupled receptor melanopsin (Opsin 4; Opn4). Here we tested the hypothesis that nonvisual opsins mediate photorelaxation in the pulmonary circulation. We discovered Opsin 3 (Opn3), Opn4, and G protein-coupled receptor kinase 2 (GRK2) in rat pulmonary arteries (PAs) and in pulmonary arterial smooth muscle cells (PASMCs), where the opsins interact directly with GRK2, as demonstrated with a proximity ligation assay. Light elicited an intensity-dependent relaxation of PAs preconstricted with phenylephrine (PE), with a maximum response between 400 and 460 nm (blue light). Wavelength-specific photorelaxation was attenuated in PAs from Opn4-/- mice and further reduced following shRNA-mediated knockdown of Opn3. Inhibition of GRK2 amplified the response and prevented physiological desensitization to repeated light exposure. Blue light also prevented PE-induced constriction in isolated PAs, decreased basal tone, ablated PE-induced single-cell contraction of PASMCs, and reversed PE-induced depolarization in PASMCs when GRK2 was inhibited. The photorelaxation response was modulated by soluble guanylyl cyclase but not by protein kinase G or nitric oxide. Most importantly, blue light induced significant vasorelaxation of PAs from rats with chronic pulmonary hypertension and effectively lowered pulmonary arterial pressure in isolated intact perfused rat lungs subjected to acute hypoxia. These findings show that functional Opn3 and Opn4 in PAs represent an endogenous "optogenetic system" that mediates photorelaxation in the pulmonary vasculature. Phototherapy in conjunction with GRK2 inhibition could therefore provide an alternative treatment strategy for pulmonary vasoconstrictive disorders.


Subject(s)
G-Protein-Coupled Receptor Kinase 2/antagonists & inhibitors , Hypertension, Pulmonary/radiotherapy , Phototherapy , Pulmonary Artery/radiation effects , Rod Opsins/physiology , Vasodilation/radiation effects , Animals , Cells, Cultured , G-Protein-Coupled Receptor Kinase 2/genetics , G-Protein-Coupled Receptor Kinase 2/metabolism , Hypertension, Pulmonary/etiology , Hypertension, Pulmonary/pathology , Hypoxia/complications , Light , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/radiation effects , Nitric Oxide/metabolism , Pulmonary Artery/cytology , Pulmonary Artery/metabolism , Rats , Rats, Sprague-Dawley , Rats, Wistar , Soluble Guanylyl Cyclase/genetics , Soluble Guanylyl Cyclase/metabolism , Vasodilation/physiology
8.
Am J Physiol Heart Circ Physiol ; 312(4): H711-H720, 2017 Apr 01.
Article in English | MEDLINE | ID: mdl-28188215

ABSTRACT

Endothelial cystathionine γ-lyase (CSEγ) contributes to cardiovascular homeostasis, mainly through production of H2S. However, the molecular mechanisms that control CSEγ gene expression in the endothelium during cardiovascular diseases are unclear. The aim of the current study is to determine the role of specific histone deacetylases (HDACs) in the regulation of endothelial CSEγ. Reduced CSEγ mRNA expression and protein abundance were observed in human aortic endothelial cells (HAEC) exposed to oxidized LDL (OxLDL) and in aortas from atherogenic apolipoprotein E knockout (ApoE-/-) mice fed a high-fat diet compared with controls. Intact murine aortic rings exposed to OxLDL (50 µg/ml) for 24 h exhibited impaired endothelium-dependent vasorelaxation that was blocked by CSEγ overexpression or the H2S donor NaHS. CSEγ expression was upregulated by pan-HDAC inhibitors and by class II-specific HDAC inhibitors, but not by other class-specific inhibitors. The HDAC6 selective inhibitor tubacin and HDAC6-specific siRNA increased CSEγ expression and blocked OxLDL-mediated reductions in endothelial CSEγ expression and CSEγ promoter activity, indicating that HDAC6 is a specific regulator of CSEγ expression. Consistent with this finding, HDAC6 mRNA, protein expression, and activity were upregulated in OxLDL-exposed HAEC, but not in human aortic smooth muscle cells. HDAC6 protein levels in aortas from high-fat diet-fed ApoE-/- mice were comparable to those in controls, whereas HDAC6 activity was robustly upregulated. Together, our findings indicate that HDAC6 is upregulated by atherogenic stimuli via posttranslational modifications and is a critical regulator of CSEγ expression in vascular endothelium. Inhibition of HDAC6 activity may improve endothelial function and prevent or reverse the development of atherosclerosis.NEW & NOTEWORTHY Oxidative injury to endothelial cells by oxidized LDL reduced cystathionine γ-lyase (CSEγ) expression and H2S production, leading to endothelial dysfunction, which was prevented by histone deacetylase 6 (HDAC6) inhibition. Our data suggest HDAC6 as a novel therapeutic target to prevent the development of atherosclerosis.


Subject(s)
Cystathionine gamma-Lyase/metabolism , Endothelium, Vascular/enzymology , Endothelium, Vascular/physiology , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylases/genetics , Animals , Apolipoproteins E/genetics , Cystathionine gamma-Lyase/biosynthesis , Cystathionine gamma-Lyase/genetics , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Endothelium, Vascular/drug effects , Histone Deacetylase 6 , Humans , Hydrogen Sulfide/metabolism , Hydrogen Sulfide/pharmacology , Lipoproteins, LDL/toxicity , Mice , Mice, Inbred C57BL , Mice, Knockout , Myocardial Contraction , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Vasodilation/drug effects , Vasodilation/genetics
9.
Am J Physiol Heart Circ Physiol ; 310(1): H71-9, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-26519030

ABSTRACT

Hydrogen sulfide (H2S) has emerged as an important gasotransmitter in the vasculature. In this study, we tested the hypothesis that H2S contributes to coronary vasoregulation and evaluated the physiological relevance of two sources of H2S, namely, cystathionine-γ-lyase (CSE) and 3-mercaptypyruvate sulfertransferase (MPST). MPST was detected in human coronary artery endothelial cells as well as rat and mouse coronary artery; CSE was not detected in the coronary vasculature. Rat coronary artery homogenates produced H2S through the MPST pathway but not the CSE pathway in vitro. In vivo coronary vasorelaxation response was similar in CSE knockout mice, wild-type mice (WT), and WT mice treated with the CSE inhibitor propargylglycine, suggesting that CSE-produced H2S does not have a significant role in coronary vasoregulation in vivo. Ex vivo, the MPST substrate 3-mercaptopyruvate (3-MP) and H2S donor sodium hydrosulfide (NaHS) elicited similar coronary vasoreactivity responses. Pyruvate did not have any effects on vasoreactivity. The vasoactive effect of H2S appeared to be nitric oxide (NO) dependent: H2S induced coronary vasoconstriction in the presence of NO and vasorelaxation in its absence. Maximal endothelial-dependent relaxation was intact after 3-MP and NaHS induced an increase in preconstriction tone, suggesting that endothelial NO synthase activity was not significantly inhibited. In vitro, H2S reacted with NO, which may, in part explain the vasoconstrictive effects of 3-MP and NaHS. Taken together, these data show that MPST rather than CSE generates H2S in coronary artery, mediating its effects through direct modulation of NO. This has important implications for H2S-based therapy in healthy and diseased coronary arteries.


Subject(s)
Coronary Vessels/enzymology , Cystathionine gamma-Lyase/metabolism , Hydrogen Sulfide/metabolism , Sulfurtransferases/metabolism , Animals , Cells, Cultured , Coronary Vessels/drug effects , Cystathionine gamma-Lyase/antagonists & inhibitors , Cystathionine gamma-Lyase/deficiency , Cystathionine gamma-Lyase/genetics , Dose-Response Relationship, Drug , Enzyme Inhibitors/pharmacology , Humans , Kinetics , Male , Mice, Knockout , Nitric Oxide/metabolism , Rats, Sprague-Dawley , Signal Transduction/drug effects , Vasodilation/drug effects , Vasodilator Agents/pharmacology
10.
J Mol Med (Berl) ; 93(12): 1341-54, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26184970

ABSTRACT

UNLABELLED: Hyperglycemia-induced reactive oxygen species (ROS) production plays a major role in the pathogenesis of diabetic vascular dysfunction. However, the underlying mechanisms remain unclear. Toll-like receptor 4 (TLR4), a key component of innate immunity, is known to be activated during diabetes. Therefore, we hypothesize that hyperglycemia activates TLR4 signaling in vascular smooth muscle cells (VSMCs) that triggers ROS production and causes vascular dysfunction. Rat mesenteric VSMCs exposed to high glucose (25 mmol/l) increased TLR4 expression and activated TLR4 signaling via upregulation of myeloid differentiation factor 88 (MyD88). TLR4 inhibitor CLI-095 significantly attenuated elevated levels of ROS and nuclear factor-kappa B (NF-κB) activity in VSMCs exposed to high glucose. Mesenteric arteries from streptozotocin-induced diabetic rats treated with CLI-095 (2 mg/kg/day) intraperitoneally for 2 weeks exhibited reduced ROS generation and attenuated noradrenaline-induced contraction. These results suggest that hyperglycemia-induced ROS generation and NF-κB activation in VSMCs are at least, in part, mediated by TLR4 signaling. Therefore, strategies to block TLR4 signaling pathways pose a promising avenue to alleviate diabetic-induced vascular complications. KEY MESSAGES: High glucose-induced TLR4 activation in vascular smooth muscle cells. Inhibition of TLR4 attenuated high glucose-induced ROS production and NF-κB activity in VSMC. Suppression of TLR4 signaling attenuated mesenteric contraction in diabetic rat.


Subject(s)
Diabetes Mellitus, Experimental/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Oxidative Stress/drug effects , Toll-Like Receptor 4/antagonists & inhibitors , Animals , Blood Glucose , Cells, Cultured , Diabetes Mellitus, Experimental/genetics , Disease Models, Animal , Gene Expression , Glucose/metabolism , Male , Muscle, Smooth, Vascular/drug effects , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/metabolism , Myocytes, Smooth Muscle/drug effects , NF-kappa B/metabolism , Protein Binding , Protein Transport , Rats , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Sulfonamides/pharmacology , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolism
11.
J Mol Cell Cardiol ; 81: 18-22, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25655932

ABSTRACT

Emerging evidence strongly supports a role for HDAC2 in the transcriptional regulation of endothelial genes and vascular function. We have recently demonstrated that HDAC2 reciprocally regulates the transcription of Arginase2, which is itself a critical modulator of endothelial function via eNOS. Moreover HDAC2 levels are decreased in response to the atherogenic stimulus OxLDL via a mechanism that is apparently dependent upon proteasomal degradation. NEDDylation is a post-translational protein modification that is tightly linked to ubiquitination and thereby protein degradation. We propose that changes in NEDDylation may modulate vascular endothelial function in part through alterations in the proteasomal degradation of HDAC2. In HAEC, OxLDL exposure augmented global protein NEDDylation. Pre-incubation of mouse aortic rings with the NEDDylation activating enzyme inhibitor, MLN4924, prevented OxLDL-induced endothelial dysfunction. In HAEC, MLN enhanced HDAC2 abundance, decreased expression and activity of Arginase2, and blocked OxLDL-mediated reduction of HDAC2. Additionally, HDAC2 was shown to be a substrate for NEDD8 conjugation and this interaction was potentiated by OxLDL. Further, HDAC2 levels were reciprocally regulated by ectopic expression of NEDD8 and the de-NEDDylating enzyme SENP8. Our findings indicate that the observed improvement in endothelial dysfunction with inhibition of NEDDylation activating enzyme is likely due to an HDAC2-dependent decrease in Arginase2. NEDDylation activating enzyme may therefore be a novel target in endothelial dysfunction and atherogenesis.


Subject(s)
Atherosclerosis/genetics , Endothelial Cells/metabolism , Endothelium, Vascular/metabolism , Histone Deacetylase 2/genetics , Protein Processing, Post-Translational , Ubiquitins/genetics , Animals , Aorta/drug effects , Aorta/metabolism , Aorta/pathology , Arginase/genetics , Arginase/metabolism , Atherosclerosis/metabolism , Atherosclerosis/pathology , Cell Line , Cyclopentanes/pharmacology , Endopeptidases/genetics , Endopeptidases/metabolism , Endothelial Cells/drug effects , Endothelial Cells/pathology , Endothelium, Vascular/drug effects , Endothelium, Vascular/pathology , Enzyme Inhibitors/pharmacology , Histone Deacetylase 2/metabolism , Humans , Lipoproteins, LDL/pharmacology , Mice , NEDD8 Protein , Proteasome Endopeptidase Complex/drug effects , Proteasome Endopeptidase Complex/metabolism , Proteolysis/drug effects , Pyrimidines/pharmacology , Signal Transduction , Tissue Culture Techniques , Ubiquitination , Ubiquitins/metabolism
12.
Proc Natl Acad Sci U S A ; 111(50): 17977-82, 2014 Dec 16.
Article in English | MEDLINE | ID: mdl-25404319

ABSTRACT

Melanopsin (opsin4; Opn4), a non-image-forming opsin, has been linked to a number of behavioral responses to light, including circadian photo-entrainment, light suppression of activity in nocturnal animals, and alertness in diurnal animals. We report a physiological role for Opn4 in regulating blood vessel function, particularly in the context of photorelaxation. Using PCR, we demonstrate that Opn4 (a classic G protein-coupled receptor) is expressed in blood vessels. Force-tension myography demonstrates that vessels from Opn4(-/-) mice fail to display photorelaxation, which is also inhibited by an Opn4-specific small-molecule inhibitor. The vasorelaxation is wavelength-specific, with a maximal response at ∼430-460 nm. Photorelaxation does not involve endothelial-, nitric oxide-, carbon monoxide-, or cytochrome p450-derived vasoactive prostanoid signaling but is associated with vascular hyperpolarization, as shown by intracellular membrane potential measurements. Signaling is both soluble guanylyl cyclase- and phosphodiesterase 6-dependent but protein kinase G-independent. ß-Adrenergic receptor kinase 1 (ßARK 1 or GRK2) mediates desensitization of photorelaxation, which is greatly reduced by GRK2 inhibitors. Blue light (455 nM) regulates tail artery vasoreactivity ex vivo and tail blood blood flow in vivo, supporting a potential physiological role for this signaling system. This endogenous opsin-mediated, light-activated molecular switch for vasorelaxation might be harnessed for therapy in diseases in which altered vasoreactivity is a significant pathophysiologic contributor.


Subject(s)
Blood Vessels/physiology , Light , Rod Opsins/metabolism , Signal Transduction/physiology , Vasodilation/physiology , Animals , Blood Vessels/metabolism , Blotting, Western , Cyclic GMP/metabolism , Cyclic Nucleotide Phosphodiesterases, Type 6/metabolism , G-Protein-Coupled Receptor Kinase 2/metabolism , Laser-Doppler Flowmetry , Mice , Myography , Reverse Transcriptase Polymerase Chain Reaction , Vasodilation/radiation effects
13.
Circ Res ; 115(4): 450-9, 2014 Aug 01.
Article in English | MEDLINE | ID: mdl-24903103

ABSTRACT

RATIONALE: Increased arginase activity contributes to endothelial dysfunction by competition for l-arginine substrate and reciprocal regulation of nitric oxide synthase (NOS). The rapid increase in arginase activity in human aortic endothelial cells exposed to oxidized low-density lipoprotein (OxLDL) is consistent with post-translational modification or subcellular trafficking. OBJECTIVE: To test the hypotheses that OxLDL triggers reverse translocation of mitochondrial arginase 2 (Arg2) to cytosol and Arg2 activation, and that this process is dependent on mitochondrial processing peptidase, lectin-like OxLDL receptor-1 receptor, and rho kinase. METHODS AND RESULTS: OxLDL-triggered translocation of Arg2 from mitochondria to cytosol in human aortic endothelial cells and in murine aortic intima with a concomitant rise in arginase activity. All of these changes were abolished by inhibition of mitochondrial processing peptidase or by its siRNA-mediated knockdown. Rho kinase inhibition and the absence of the lectin-like OxLDL receptor-1 in knockout mice also ablated translocation. Aminoterminal sequencing of Arg2 revealed 2 candidate mitochondrial targeting sequences, and deletion of either of these confined Arg2 to the cytoplasm. Inhibitors of mitochondrial processing peptidase or lectin-like OxLDL receptor-1 knockout attenuated OxLDL-mediated decrements in endothelial-specific NO production and increases in superoxide generation. Finally, Arg2(-/-) mice bred on an ApoE(-/-) background showed reduced plaque load, reduced reactive oxygen species production, enhanced NO, and improved endothelial function when compared with ApoE(-/-) controls. CONCLUSIONS: These data demonstrate dual distribution of Arg2, a protein with an unambiguous mitochondrial targeting sequence, in mammalian cells, and its reverse translocation to cytoplasm by alterations in the extracellular milieu. This novel molecular mechanism drives OxLDL-mediated arginase activation, endothelial NOS uncoupling, endothelial dysfunction, and atherogenesis.


Subject(s)
Aorta/enzymology , Arginase/metabolism , Endothelial Cells/enzymology , Lipoproteins, LDL/metabolism , Metalloendopeptidases/metabolism , Mitochondria/enzymology , rho-Associated Kinases/metabolism , Amino Acid Sequence , Animals , Aorta/drug effects , Aorta/pathology , Aorta/physiopathology , Aortic Diseases/enzymology , Aortic Diseases/genetics , Aortic Diseases/pathology , Aortic Diseases/physiopathology , Aortic Diseases/prevention & control , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Arginase/genetics , Atherosclerosis/enzymology , Atherosclerosis/genetics , Atherosclerosis/pathology , Atherosclerosis/physiopathology , Atherosclerosis/prevention & control , Cells, Cultured , Cytosol/enzymology , Disease Models, Animal , Endothelial Cells/drug effects , Enzyme Activation , Humans , Male , Metalloendopeptidases/antagonists & inhibitors , Metalloendopeptidases/genetics , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Mitochondria/drug effects , Molecular Sequence Data , Protein Kinase Inhibitors/pharmacology , Protein Transport , RNA Interference , Scavenger Receptors, Class E/deficiency , Scavenger Receptors, Class E/genetics , Signal Transduction , Time Factors , Transfection , rho-Associated Kinases/antagonists & inhibitors , Mitochondrial Processing Peptidase
14.
Arterioscler Thromb Vasc Biol ; 34(7): 1556-1566, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24833798

ABSTRACT

OBJECTIVE: Arginase 2 (Arg2) is a critical target in atherosclerosis because it controls endothelial nitric oxide, proliferation, fibrosis, and inflammation. Regulators of Arg2 transcription in the endothelium have not been characterized. The goal of the current study is to determine the role of specific histone deacetylases (HDACs) in the regulation of endothelial Arg2 transcription and endothelial function. APPROACH AND RESULTS: The HDAC inhibitor trichostatin A increased levels of Arg2 mRNA, protein, and activity in both human aortic endothelial cells and mouse aortic rings. These changes occurred in both time- and dose-dependent patterns and resulted in Arg2-dependent endothelial dysfunction. Trichostatin A and the atherogenic stimulus oxidized low-density lipoprotein enhanced the activity of common promoter regions of Arg2. HDAC inhibition with trichostatin A also decreased endothelial nitric oxide, and these effects were blunted by arginase inhibition. Nonselective class I HDAC inhibitors enhanced Arg2 expression, whereas the only selective inhibitor that increased Arg2 expression was mocetinostat, a selective inhibitor of HDACs 1 and 2. Additionally, mouse aortic rings preincubated with mocetinostat exhibited dysfunctional relaxation. Overexpression of HDAC2 (but not HDAC 1, 3, or 8) cDNA in human aortic endothelial cells suppressed Arg2 expression in a concentration-dependent manner, and siRNA knockdown of HDAC2 enhanced Arg2 expression. Chromatin immunoprecipitation indicated direct binding of HDAC2 to the Arg2 promoter, and HDAC2 overexpression in human aortic endothelial cells blocked oxidized low-density lipoprotein-mediated activation of the Arg2 promoter. Finally, overexpression of HDAC2 blocked oxidized low-density lipoprotein-mediated vascular dysfunction. CONCLUSIONS: HDAC2 is a critical regulator of Arg2 expression and thereby endothelial nitric oxide and endothelial function. Overexpression or activation of HDAC2 represents a novel therapy for endothelial dysfunction and atherosclerosis.


Subject(s)
Arginase/metabolism , Endothelial Cells/enzymology , Endothelium, Vascular/enzymology , Histone Deacetylase 2/metabolism , Transcription, Genetic , Animals , Arginase/antagonists & inhibitors , Arginase/genetics , Binding Sites , Dose-Response Relationship, Drug , Endothelial Cells/drug effects , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiopathology , Gene Expression Regulation, Enzymologic , HEK293 Cells , Histone Deacetylase 2/antagonists & inhibitors , Histone Deacetylase Inhibitors/pharmacology , Humans , Lipoproteins, LDL/metabolism , Mice , Mice, Inbred C57BL , Nitric Oxide/metabolism , Promoter Regions, Genetic , RNA Interference , RNA, Messenger/metabolism , Time Factors , Transcription, Genetic/drug effects , Transfection , Vasodilation , Vasodilator Agents/pharmacology
15.
Atherosclerosis ; 231(1): 91-4, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24125417

ABSTRACT

BACKGROUND: Cigarette smoke increases the risk of several cardiovascular diseases and has synergistic detrimental effects when present with other risks that contribute to its pathogenesis. Oxidative injury to the endothelium via reactive oxygen species (ROS) and nitric oxide (NO) dysregulation is a common denominator of smoking-induced alterations in vascular function. However, the mechanisms underlying ROS and NO dysregulation due to smoking remain unclear. We tested if arginase (Arg) activation/upregulation contributes to this phenomenon by constraining nitric oxide synthase (NOS) activity. METHODS: Arg2 knockout (Arg2(-/-)) and control C57BL/6J mice were either exposed to cigarette smoke, 6 h/day/2 weeks (Second Hand Smoking; SHS) or housed in normal environment (Non Smoking; NS). Arg activity, NO and ROS levels were determined by measuring urea production, fluorescent dye (DAF), and dihydroethedium (DHE) respectively in isolated mouse aorta. RESULTS: Arg activity and ROS levels were higher NO lower in SHS compared to NS mice. SHS failed to lower NO levels in Arg2(-/-) mice. Endothelial dependent vasodilation (EDV) was attenuated in SHS mice as compared to controls (78.80% ± 8 vs 46.58% ± 5). This impaired EDV was abolished in Arg2(-/-) mice (67.48% ± 7 in SHS vs. 78.80% ± 8 in NS). Vascular stiffness was increased in SHS mice as compared to NS controls but remained unchanged in Arg2(-/-) mice. CONCLUSION: Endothelial NOS is uncoupled by smoking exposure, leading to endothelial dysfunction and vascular stiffness, a process that is prevented by Arg2 deletion. Hence, we identify Arg2 upregulation as a critical pathogenic factor and target for therapy in oxidative injury following smoking exposure through reciprocal regulation of endothelial NOS.


Subject(s)
Arginase/metabolism , Endothelium, Vascular/physiopathology , Nitric Oxide/blood , Tobacco Smoke Pollution/adverse effects , Animals , Aorta/drug effects , Aorta/physiopathology , Enzyme Activation , Male , Mice , Mice, Inbred C57BL , Nitric Oxide Synthase Type III/metabolism , Reactive Oxygen Species/blood , Vascular Stiffness/drug effects
17.
Am J Physiol Heart Circ Physiol ; 305(5): H651-66, 2013 Sep 01.
Article in English | MEDLINE | ID: mdl-23792682

ABSTRACT

Reduced production of nitric oxide (NO) is one of the first indications of endothelial dysfunction and precedes overt cardiovascular disease. Increased expression of Arginase has been proposed as a mechanism to account for diminished NO production. Arginases consume l-arginine, the substrate for endothelial nitric oxide synthase (eNOS), and l-arginine depletion is thought to competitively reduce eNOS-derived NO. However, this simple relationship is complicated by the paradox that l-arginine concentrations in endothelial cells remain sufficiently high to support NO synthesis. One mechanism proposed to explain this is compartmentalization of intracellular l-arginine into distinct, poorly interchangeable pools. In the current study, we investigated this concept by targeting eNOS and Arginase to different intracellular locations within COS-7 cells and also BAEC. We found that supplemental l-arginine and l-citrulline dose-dependently increased NO production in a manner independent of the intracellular location of eNOS. Cytosolic arginase I and mitochondrial arginase II reduced eNOS activity equally regardless of where in the cell eNOS was expressed. Similarly, targeting arginase I to disparate regions of the cell did not differentially modify eNOS activity. Arginase-dependent suppression of eNOS activity was reversed by pharmacological inhibitors and absent in a catalytically inactive mutant. Arginase did not directly interact with eNOS, and the metabolic products of arginase or downstream enzymes did not contribute to eNOS inhibition. Cells expressing arginase had significantly lower levels of intracellular l-arginine and higher levels of ornithine. These results suggest that arginases inhibit eNOS activity by depletion of substrate and that the compartmentalization of l-arginine does not play a major role.


Subject(s)
Arginase/metabolism , Arginine/metabolism , COS Cells/metabolism , Endothelium, Vascular/metabolism , Nitric Oxide Synthase Type III/metabolism , Animals , Aorta/cytology , Aorta/metabolism , Arginine/pharmacology , COS Cells/cytology , Cattle , Cell Line , Cells, Cultured , Chlorocebus aethiops , Citrulline/pharmacology , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Models, Animal , Nitric Oxide/metabolism , Ornithine/metabolism
18.
Exp Gerontol ; 48(2): 128-35, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23159957

ABSTRACT

UNLABELLED: Cardiovascular dysfunction is a primary independent predictor of age-related morbidity and mortality. Frailty is associated with activation of inflammatory pathways and fatigue that commonly presents and progresses with age. Interleukin 10 (IL-10), the cytokine synthesis inhibitory factor, is an anti-inflammatory cytokine produced by immune and non-immune cells. Homozygous deletion of IL-10 in mice yields a phenotype that is consistent with human frailty, including age-related increases in serum inflammatory mediators, muscular weakness, higher levels of IGF-1 at midlife, and early mortality. While emerging evidence suggests a role for IL-10 in vascular protection, a clear mechanism has not yet been elucidated. METHODS: In order to evaluate the role of IL-10 in maintenance of vascular function, force tension myography was utilized to access ex-vivo endothelium dependent vasorelaxation in vessels isolated from IL-10 knockout IL-10(tm/tm) and control mice. Pulse wave velocity ((PWV), index of stiffness) of vasculature was measured using ultrasound and blood pressure was measured using the tail cuff method. Echocardiography was used to elucidated structure and functional changes in the heart. RESULTS: Mean arterial pressures were significantly higher in IL-10(tm/tm) mice as compared to C57BL6/wild type (WT) controls. PWV was increased in IL-10(tm/tm) indicating stiffer vasculature. Endothelial intact aortic rings isolated from IL-10(tm/tm) mice demonstrated impaired vasodilation at low acetylcholine doses and vasoconstriction at higher doses whereas vasorelaxation responses were preserved in rings from WT mice. Cyclo-oxygenase (COX-2)/thromboxane A2 inhibitors improved endothelial dependent vasorelaxation and reversed vasoconstriction. Left ventricular end systolic diameter, left ventricular mass, isovolumic relaxation time, fractional shortening and ejection fraction were all significantly different in the aged IL-10(tm/tm) mice compared to WT mice. CONCLUSION: Aged IL-10(tm/tm) mice have stiffer vessels and decreased vascular relaxation due to an increase in eicosanoids, specifically COX-2 activity and resultant thromboxane A2 receptor activation. Our results also suggest that aging IL-10(tm/tm) mice have an increased heart size and impaired cardiac function compared to age-matched WT mice. While further studies will be necessary to determine if this age-related phenotype develops as a result of inflammatory pathway activation or lack of IL-10, it is essential for maintaining the vascular compliance and endothelial function during the aging process. Given that a similar cardiovascular phenotype is present in frail, older adults, these findings further support the utility of the IL-10(tm/tm) mouse as a model of frailty.


Subject(s)
Aging/immunology , Aorta/immunology , Cardiovascular Diseases/immunology , Endothelium, Vascular/immunology , Inflammation Mediators/metabolism , Inflammation/immunology , Interleukin-10/deficiency , Age Factors , Aging/genetics , Animals , Aorta/drug effects , Aorta/physiopathology , Arterial Pressure , Cardiovascular Diseases/genetics , Cardiovascular Diseases/physiopathology , Cyclooxygenase 2/metabolism , Cyclooxygenase 2 Inhibitors/pharmacology , Dose-Response Relationship, Drug , Echocardiography, Doppler , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiopathology , Genotype , Inflammation/genetics , Inflammation/physiopathology , Interleukin-10/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Myography , Phenotype , Pulse Wave Analysis , Stroke Volume , Thromboxane A2/antagonists & inhibitors , Thromboxane A2/metabolism , Vascular Stiffness , Vasoconstriction , Vasoconstrictor Agents/pharmacology , Vasodilation , Vasodilator Agents/pharmacology , Ventricular Function, Left
19.
Arterioscler Thromb Vasc Biol ; 32(10): 2452-60, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22879585

ABSTRACT

OBJECTIVE: To characterize the relationship between the expression of epidermal growth factor (EGF)-like ligands and vascular nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression and activity in a primate model of atherosclerosis. METHODS AND RESULTS: Adult male Cynomolgus monkeys were fed a normal or atherogenic (AS) diet for 45 months, after which animals from the AS group were placed on a normal diet for 8 months (regression). The expression of membrane-associated EGF-like ligands was increased in arteries from animals on the AS diet and normalized in the regression group. EGF-like ligands were distributed throughout atherosclerotic vessels but predominantly colocalized with macrophages. Consistent with ligand shedding, circulating heparin-bound EGF was elevated in the plasma of AS monkeys but not in those on regression diet. Atherosclerosis was associated with the activation of EGF receptor signaling. Expression of NADPH oxidase subunits Nox1 and Nox2 but not Nox4 or Nox5 was increased in arteries from monkeys on the AS diet and returned to normal with regression. Levels of Nox1 and Nox2 positively correlated with EGF-like ligands. In cultured monkey smooth muscle cells, treatment with EGF-like ligands increased Nox1 expression and activity. CONCLUSIONS: These data identify EGF-like ligands as potential modulators of atherogenesis, resulting in part from increased vascular NADPH oxidase activity.


Subject(s)
Arteries/metabolism , Atherosclerosis/metabolism , Epidermal Growth Factor/metabolism , NADPH Oxidases/metabolism , Animals , Atherosclerosis/etiology , Atherosclerosis/pathology , Cells, Cultured , Diet, Atherogenic/adverse effects , Disease Models, Animal , Ligands , Macaca fascicularis , Male , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/pathology , Signal Transduction
20.
Free Radic Biol Med ; 52(9): 1806-19, 2012 May 01.
Article in English | MEDLINE | ID: mdl-22387196

ABSTRACT

The NADPH oxidases (Noxs) are a family of transmembrane oxidoreductases that produce superoxide and other reactive oxygen species (ROS). Nox5 was the last of the conventional Nox isoforms to be identified and is a calcium-dependent enzyme that does not depend on accessory subunits for activation. Recently, Nox5 was shown to be expressed in human blood vessels and therefore the goal of this study was to determine whether nitric oxide (NO) can modulate Nox5 activity. Endogenously produced NO potently inhibited basal and stimulated Nox5 activity and this inhibition was reversible with chronic, but not acute, exposure to L-NAME. Nox5 activity was reduced by NO donors, iNOS, and eNOS and in endothelial cells and LPS-stimulated smooth muscle cells in a manner dependent on NO concentration. ROS production was diminished by NO in an isolated enzyme activity assay replete with surplus calcium and NADPH. There was no evidence for NO-dependent changes in tyrosine nitration, glutathiolation, or phosphorylation of Nox5. In contrast, there was evidence for the increased nitrosylation of Nox5 as determined by the biotin-switch assay and mass spectrometry. Four S-nitrosylation sites were identified and of these, mutation of C694 dramatically lowered Nox5 activity, NO sensitivity, and biotin labeling. Furthermore, coexpression of the denitrosylation enzymes thioredoxin 1 and GSNO reductase prevented NO-dependent inhibition of Nox5. The potency of NO against other Nox enzymes was in the order Nox1 ≥ Nox3 > Nox5 > Nox2, whereas Nox4 was refractory. Collectively, these results suggest that endogenously produced NO can directly S-nitrosylate and inhibit the activity of Nox5.


Subject(s)
Membrane Proteins/metabolism , NADPH Oxidases/metabolism , Nitric Oxide/physiology , Nitroso Compounds/metabolism , Animals , Blotting, Western , COS Cells , Calcium/metabolism , Cell Line , Chlorocebus aethiops , Humans , Mass Spectrometry , NADPH Oxidase 5 , Nitric Oxide Donors/pharmacology , Phosphorylation , Reactive Oxygen Species/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...