Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.3.1 (NADPH oxidase)
11,281 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Matrix metalloproteinases (MMPs) play a pivotal role in angiogenesis, atherogenesis, vascular remodeling after vascular injury, and instability of atherosclerotic plaque. The present study was undertaken to investigate the effect of lysophosphatidylcholine, a major component of oxidized low density lipoprotein (LDL), on the regulation of MMPs in cultured bovine aortic endothelial cells (BAECs). Furthermore, we explored the potential role of oxidative stress in the regulation of MMP. LPC increased the secretion of gelatinolytic activity, as well as, protein of MMP-2 from BAECs. The stimulation of BAEC with superoxide increased the production of MMP-2 and it also induced its activation. Electron spin resonance (ESR) with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as spin trap agent demonstrated that lysophosphatidycholine (LPC) induced generation of reactive oxygen (ROS) species from BAECs. The inhibition of NADH/NADPH oxidase, one of the potential sources of superoxide in endothelial cells, attenuated the effect of LPC. Our findings suggest that LPC might activate the endothelial NADH/NADPH oxidase to enhance superoxide production, and it might, in turn, enhance MMP-2 induction.
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PMID:Lysophosphatidylcholine increases the secretion of matrix metalloproteinase 2 through the activation of NADH/NADPH oxidase in cultured aortic endothelial cells. 1122 25

Targeted ablation of the surfactant protein D (SP-D) gene caused progressive pulmonary emphysema associated with pulmonary infiltration by foamy alveolar macrophages (AMs), increased hydrogen peroxide production, and matrix metalloproteinase (MMP)-2, -9, and -12 expression. In the present study, the mechanisms by which SP-D influences macrophage MMP activity were assessed in AMs from SP-D(-/-) mice. Tissue lipid peroxides and reactive carbonyls were increased in lungs of SP-D(-/-) mice, indicating oxidative stress. Immunohistochemical staining of AMs from SP-D(-/-) mice demonstrated that NF-kappaB was highly expressed and translocated to the nucleus. Increased NF-kappaB binding was detected by EMSA in nuclear extracts of AMs isolated from SP-D(-/-) mice. Antioxidants N-acetylcysteine and pyrrolidine dithiocarbamate inhibited MMP production by AMs from SP-D(-/-) mice. To assess whether increased oxidant production influenced NF-kappaB activation and production of MMP-2 and -9, AMs from SP-D(-/-) mice were treated with the NADPH oxidase inhibitors diphenylene iodonium chloride and apocynin. Inhibition of NADPH oxidase suppressed NF-kappaB binding by nuclear extracts and decreased production of MMP-2 and 9 in AMs from SP-D(-/-) mice. SN-50, a synthetic NF-kappaB-inhibitory peptide, decreased MMP production by AMs from SP-D(-/-) mice. Oxidant production and reactive oxygen species were increased in lungs of SP-D(-/-) mice, in turn activating NF-kappaB and MMP expression. SP-D plays an unexpected inhibitory role in the regulation of NF-kappaB in AMs.
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PMID:Surfactant protein D regulates NF-kappa B and matrix metalloproteinase production in alveolar macrophages via oxidant-sensitive pathways. 1139 May 5

Mechanical stretch is a hallmark of arterial hypertension and leads to vessel wall remodeling, which involves matrix metalloproteinases (MMPs). Because mechanical stretch is further capable of inducing reactive oxygen species (ROS) formation via the NAD(P)H oxidase, we assessed whether mechanical stretch enhances MMP expression and activity in a NAD(P)H oxidase-dependent manner. Therefore, vascular smooth muscle cells (VSMCs) isolated from C57BL/6 mice were exposed to cyclic mechanical stretch. The impact of ROS was assessed using VSMCs isolated from p47phox-/- mice, deficient for a NAD(P)H oxidase subunit responsible for ROS formation. Transcript levels were investigated by cDNA array and confirmed by RT-PCR. ROS formation was determined by DCF fluoroscopy and MMP-2 activity by zymography. Mechanical stretch of wild-type VSMCs resulted in a rapid ROS formation and p47phox membrane translocation that is followed by an increase in Nox-1 transcripts. ROS formation was completely abrogated in p47phox-/- VSMCs. cDNA array further revealed an increase of MMP-2 mRNA in response to mechanical stretch, which was validated by RT-PCR. Using p47phox-/- VSMCs, this increase in MMP-2 mRNA was completely blunted. mRNA expression of tissue inhibitor of MMP-2 TIMP-1 and TIMP-2 and membrane-type 1 MMP was unaffected by mechanical stretch. Gelatinolytic activity of pro-MMP-2 has been increased rapidly in wild-type VSMCs and was completely abolished in p47phox-/- VSMCs. These results indicate that mechanical stretch induces ROS formation via the NAD(P)H oxidase and thereby enhances MMP-2 mRNA expression and pro-MMP-2 release. These results are consistent with the notion that in arterial hypertension, reactive oxygen species are involved in vascular remodeling via MMP activation. The full text of this article is available online at http://www.circresaha.org.
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PMID:Mechanical stretch enhances mRNA expression and proenzyme release of matrix metalloproteinase-2 (MMP-2) via NAD(P)H oxidase-derived reactive oxygen species. 1275 Mar 13

TGF-beta produced by keratinocytes in response to UVB (290-320 nm) is a potential mediator for effects of acute and chronic solar radiation on skin. This study was designed to determine whether reactive oxygen species (ROS) mediate UVB-induced TGF-beta biosynthesis in keratinocytes and the subsequent activation of the latent TGF-beta complex. UVB irradiation elevated both total (latent plus active) and active TGF-beta in the keratinocyte supernatants, with a greater increase in the active form. UVB irradiation induced up to a 30% increase in ROS, and the ROS were detected up to 90 min after irradiation. NAC and Trolox, cytoplasmic ROS scavengers, abolished the UVB-induced TGF-beta and intracellular ROS, suggesting that UVB-induced ROS are involved in TGF-beta regulation. Inhibitors of NADPH oxidase activity, DPI and apocynin, decreased UVB-induced ROS. The increase in NADPH oxidase activity was mediated by EGFR activation. UVB-induced ROS also activated latent TGF-beta complex by stimulating MMP-2 and -9 activities. In summary, physiological doses of UVB increase intracellular ROS, which upregulate TGF-beta biosynthesis and activation of TGF-beta through increased activity of MMPs.
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PMID:Involvement of UVB-induced reactive oxygen species in TGF-beta biosynthesis and activation in keratinocytes. 1574 85

Accumulating evidence suggests that high concentrations of leptin observed in obesity and diabetes may contribute to their adverse effects on cardiovascular health. Metformin monotherapy is associated with reduced macrovascular complications in overweight patients with type 2 diabetes. It is uncertain whether such improvement in the cardiovascular outcome is related to specific vasculoprotective effects of this drug. In the present study, we determined the effect of leptin on human aortic smooth muscle cell (HASMC) proliferation and matrix metalloproteinase (MMP)-2 expression, the signaling pathways mediating these effects, and the modulatory effect of metformin on these parameters. Incubation of HASMCs with leptin enhanced the proliferation and MMP-2 expression in these cells and increased the generation of intracellular reactive oxygen species (ROS). These effects were abolished by vitamin E. Inhibition of NAD(P)H oxidase and protein kinase C (PKC) suppressed the effect of leptin on ROS production. In HASMCs, leptin induced PKC, extracellular signal-regulated kinase (ERK)1/2, and nuclear factor-kappaB (NF-kappaB) activation and inhibition of these signaling pathways abrogated HASMC proliferation and MMP-2 expression induced by this hormone. Treatment of HASMCs with metformin decreased leptin-induced ROS production and activation of PKC, ERK1/2, and NF-kappaB. Metformin also inhibited the effect of leptin on HASMC proliferation and MMP-2 expression. Overall, these results demonstrate that leptin induced HASMC proliferation and MMP-2 expression through a PKC-dependent activation of NAD(P)H oxidase with subsequent activation of the ERK1/2/NF-kappaB pathways and that therapeutic metformin concentrations effectively inhibit these biological effects. These results suggest a new mechanism by which metformin may improve cardiovascular outcome in patients with diabetes.
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PMID:Signaling pathways involved in human vascular smooth muscle cell proliferation and matrix metalloproteinase-2 expression induced by leptin: inhibitory effect of metformin. 1598 26

Matrix metalloproteinases (MMPs), aldosterone, and reactive oxygen species (ROS) are implicated in myocardial remodeling. Although ROS, cytokines, and neurohormones regulate MMP in cardiac fibroblasts, it is unknown whether aldosterone regulates MMP in cardiomyocytes. Therefore, we tested the hypothesis that aldosterone regulates MMP in cultured adult rat ventricular myocytes (ARVMs). ARVMs were treated with aldosterone for 24 hours, and MMP-2 and MMP-9 activities were measured by zymography. Aldosterone (50 nmol/L) increased MMP-2 (43+/-5%) and MMP-9 (55+/-15%; P<0.001 for both) activities. Pretreatment with spironolactone (100 nmol/L) abolished the aldosterone-induced increase in MMP activities. Aldosterone (50 nmol/L; 30 minutes) increased mitogen/extracellular signal-regulated kinase (MEK) (31+/-3%) and extracellular signal-regulated kinase 1/2 (ERK1/2; 41+/-7%; P<0.001 for both) phosphorylation. U0126 (10 micromol/L), an MEK1/2 inhibitor, abolished the aldosterone-induced increase in MMP activities. Aldosterone increased intracellular ROS as assessed by dichlorofluorescein diacetate (27+/-4%; P<0.05). This increase was inhibited by apocynin, an NADPH oxidase inhibitor. Apocynin likewise inhibited aldosterone-induced ERK1/2 phosphorylation and the increase in MMP activities. Furthermore, the antioxidants MnTMPyP and N-acetylcysteine inhibited the aldosterone-induced increase in ERK1/2 phosphorylation and MMP activities, respectively. Protein kinase C (PKC) is implicated in the nongenomic effects of aldosterone. To test the role of PKC, ARVMs were pretreated with chelerythrine, a PKC inhibitor. Chelerythrine prevented the aldosterone-induced increase in ERK1/2 phosphorylation and MMP activities. Thus, aldosterone induces MMP activity in ARVM via activation of the mineralocorticoid receptor, PKC, and ROS-dependent activation of the MEK/ERK pathway. NADPH oxidase is a likely source of ROS in this system.
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PMID:Aldosterone stimulates matrix metalloproteinases and reactive oxygen species in adult rat ventricular cardiomyocytes. 1604 62

Modified low-density lipoprotein (LDL) induces reactive oxygen species (ROS) production by vascular cells. It is unknown if specific oxidized components in these LDL particles such as oxidized-1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (ox-PAPC) can stimulate ROS production. Bovine aortic endothelial cells (BAEC) were incubated with ox-PAPC (50 microg/ml). At 4 h, ox-PAPC significantly enhanced the rate of O2- production. Pretreatment of BAEC in glucose-free Dulbecco's modified Eagle's medium plus 10 mM 2-deoxyglucose (2-DOG), the latter being an antimetabolite that blocks NADPH production by the pentose shunt, significantly reduced the rate of O2- production. The intensity of NAD(P)H autofluorescence decreased by 28 +/- 12% in BAEC incubated with ox-PAPC compared to untreated cells, with a further decrease in the presence of 2-DOG. Ox-PAPC also increased Nox4 mRNA expression by 2.4-fold +/- 0.1 while pretreatment of BAEC with the small interfering RNA (siNox4) attenuated Nox4 RNA expression. Ox-PAPC further reduced the level of glutathione while pretreatment with apocynin (100 microM) restored the GSH level (control = 22.54 +/- 0.23, GSH = 18.06 +/- 0.98, apocynin = 22.55 +/- 0.60, ox-PAPC + apocynin = 21.17 +/- 0.36 nmol/10(6) cells). Treatment with ox-PAPC also increased MMP-2 mRNA expression accompanied by a 1.5-fold increase in MMP-2 activity. Ox-PAPC induced vascular endothelial OO2-(.) production that appears to be mediated largely by NADPH oxidase activity.
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PMID:Oxidized-1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine induces vascular endothelial superoxide production: implication of NADPH oxidase. 1627 86

Activated matrix metalloproteinases (MMPs) in patients with acute coronary syndromes may contribute to plaque destabilization. Tumor necrosis factor-alpha (TNF-alpha) enhances NAD (P) H oxidase-dependent reactive oxygen species (ROS) formation and ROS induce MMP-2. In the present study, the effects of a potent water-soluble antioxidant, salvianolic acid B (SalB), derived from a Chinese herb, Salvia miltiorrhiza, on the expression of MMP-2 by TNF-alpha-treated human aortic smooth muscle cells (HASMCs) were investigated. In this study, salvianolic acid B scavenged H2O2 in a dose-dependent manner in test tube. We found that SalB, as well as NADPH oxidase inhibitors, DPI or apocynin, and antioxidant NAC, inhibited TNF-alpha-induced MMP-2 mRNA, protein expression, and gelatinolytic activity in HASMCs in a concentration-dependent manner. We also observed a dose-dependent decrease in ROS production and NADPH oxidase activity induced by TNF-alpha in the presence of SalB. SalB also significantly inhibited angiotensin II or H2O2-induced MMP-2 mRNA and protein expression and gelatinolytic activity in HASMCs. Our data point out that the importance of NADPH oxidase-dependent ROS generation in the control of SalB inhibition of TNF-alpha-induced MMP-2 expression and activity.
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PMID:Salvianolic acid B from Salvia miltiorrhiza inhibits tumor necrosis factor-alpha (TNF-alpha)-induced MMP-2 upregulation in human aortic smooth muscle cells via suppression of NAD(P)H oxidase-derived reactive oxygen species. 1671 3

Angiotensin (ANG) II (AngII) and aldosterone contribute to the development of interstitial cardiac fibrosis. We investigated the potential role of a Nox2-containing NADPH oxidase in aldosterone-induced fibrosis and the involvement of this mechanism in AngII-induced effects. Nox2-/- mice were compared with matched wild-type controls (WT). In WT mice, subcutaneous (s.c.) AngII (1.1 mg/kg/day for 2 wk) significantly increased NADPH oxidase activity, interstitial fibrosis (11.5+/-1.0% vs. 7.2+/-0.7%; P<0.05), expression of fibronectin, procollagen I, and connective tissue growth factor mRNA, MMP-2 activity, and NF-kB activation. These effects were all inhibited in Nox2-/- hearts. The mineralocorticoid receptor antagonist spironolactone inhibited AngII-induced increases in NADPH oxidase activity and the increase in interstitial fibrosis. In a model of mineralocorticoid-dependent hypertension involving chronic aldosterone infusion (0.2 mg/kg/day) and a 1% Na Cl diet ("ALDO"), WT animals exhibited increased NADPH oxidase activity, pro-fibrotic gene expression, MMP-2 activity, NF-kB activation, and significant interstitial cardiac fibrosis (12.0+/-1.7% with ALDO vs. 6.3+/-0.3% without; P<0.05). These effects were inhibited in Nox2-/- ALDO mice (e.g., fibrosis 6.8+/-0.8% with ALDO vs. 5.8+/-1.0% without ALDO; P=NS). These results suggest that aldosterone-dependent activation of a Nox2-containing NADPH oxidase contributes to the profibrotic effect of AngII in the heart as well as the fibrosis seen in mineralocorticoid-dependent hypertension.
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PMID:Aldosterone mediates angiotensin II-induced interstitial cardiac fibrosis via a Nox2-containing NADPH oxidase. 1672 Jul 35

Angiotensin II (Ang-II) plays pivotal roles in the progression of left ventricular (LV) remodeling in diseased hearts; it remains to be elucidated how Ang-II links to degradation of the extracellular matrix (ECM). Using hypertensive Dahl salt-sensitive rats that show the distinctive transition from concentric LV hypertrophy to LV remodeling, we chronically treated them with an angiotensin type-1 receptor blocker (telmisartan 5 mg/kg/day, ARB group) or vehicle (0.5% CMC, CHF group). During the process of LV remodeling, we assessed, (1) in-vivo LV shape and function; (2) animal survival; (3) amounts of ECM in LV using a scanning electron microscope (SEM); (4) mRNA (by real time RT-PCR) and protein (by immunoblotting) levels in LV of NADPH oxidase, glutathione peroxidase-1 (GPX-1), and matrix metalloproteinase (MMP)-2, -9, and -13; (5) immunohistochemical staining of myocardial 4-hydroxy-2-nonenal and 8-hydroxy-2'-deoxyguanosine; (6) nuclear factor kappa-B (NFkappaB) protein levels in the nuclear extract; and (7) endogenous activities of MMP-2 and -9 by an antibody capture method. Compared with CHF, ARB group showed an improvement of survival and preserved LV shape and function, and ECM density in SEM that was accompanied by decreases in oxidative stress-mediated protein degenerations, activities of GPX-1, NADPH oxidase, NFkappaB, and MMP-2, -9, and -13. Local activation of Ang-II in hypertrophic LV triggers MMP-mediated ECM degradation, namely LV remodeling, at least in part, through NADPH oxidase-induced oxidative stress and the subsequent NFkappaB activation.
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PMID:Angiotensin II, oxidative stress, and extracellular matrix degradation during transition to LV failure in rats with hypertension. 1704 85


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