Phagocytes such as neutrophils play a vital role in host defense against microbial pathogens. The anti-microbial function of neutrophils is based on the production of superoxide anion (O2(.-)), which generates other microbicidal reactive oxygen species (ROS) and release of antimicrobial peptides and proteins. The enzyme responsible for O2(.-) production is called the NADPH oxidase or respiratory burst oxidase. This multicomponent enzyme system is composed of two transmembrane proteins (p22phox and gp91phox, also called NOX2, which together form the cytochrome b(558)) and four cytosolic proteins (p47phox, p67phox, p40phox and a GTPase Rac1 or Rac2), which assemble at membrane sites upon cell activation. NADPH oxidase activation in phagocytes can be induced by a large number of soluble and particulate agents. This process is dependent on the phosphorylation of the cytosolic protein p47phox. p47phox is a 390 amino acids protein with several functional domains: one phox homology (PX) domain, two src homology 3 (SH3) domains, an auto-inhibitory region (AIR), a proline rich domain (PRR) and has several phosphorylated sites located between Ser303 and Ser379. In this review, we will describe the structure of p47phox, its phosphorylation and discuss how these events regulate NADPH oxidase activation.
*Disease ; Enzyme Activation ; Humans ; Membrane Glycoproteins/chemistry/*metabolism ; NADPH Oxidase/chemistry/genetics/*metabolism ; Phagocytes/cytology/*metabolism ; Phosphorylation ; Protein Conformation

Production of reactive oxygen species (ROS) is a conserved immune response primarily mediated by NADPH oxidases (NOXs), also known in plants as respiratory burst oxidase homologs (RBOHs). Most microbe-associated molecular patterns (MAMPs) trigger a very fast and transient ROS burst in plants. However, recently, we found that lipopolysaccharides (LPS), a typical bacterial MAMP, triggered a biphasic ROS burst. In this study, we isolated mutants defective in LPS-triggered biphasic ROS burst (delt) in Arabidopsis, and cloned the DELT1 gene that was shown to encode RBOHD. In the delt1-2 allele, the antepenultimate residue, glutamic acid (E919), at the C-terminus of RBOHD was mutated to lysine (K). E919 is a highly conserved residue in NADPH oxidases, and a mutation of the corresponding residue E568 in human NOX2 has been reported to be one of the causes of chronic granulomatous disease. Consistently, we found that residue E919 was indispensable for RBOHD function in the MAMP-induced ROS burst and stomatal closure. It has been suggested that the mutation of this residue in other NADPH oxidases impairs the protein's stability and complex assembly. However, we found that the E919K mutation did not affect RBOHD protein abundance or the ability of protein association, suggesting that the residue E919 in RBOHD might have a regulatory mechanism different from that of other NOXs. Taken together, our results confirm that the antepenultimate residue E is critical for NADPH oxidases and provide a new insight into the regulatory mechanisms of RBOHD.
Agrobacterium tumefaciens/metabolism* ; Alleles ; Arabidopsis/metabolism* ; Arabidopsis Proteins/genetics* ; Gene Expression Regulation, Plant ; Genetic Techniques ; Humans ; Lipopolysaccharides/metabolism* ; Luminescence ; Mutation ; NADPH Oxidase 2/chemistry* ; NADPH Oxidases/genetics* ; Plant Stomata/metabolism* ; Protein Domains ; Reactive Oxygen Species/metabolism* ; Nicotiana/metabolism*

OBJECTIVETo observe the effect of sesamin (Ses) on pulmonary vascular remodeling in rats with monocrotaline ( MCT)-induced pulmonary hypertension (PH).

METHODTotally 48 male Sprague-Dawley (SD) rats were fed adaptively for one week and then divided into the normal control group, the MCT group, the MCT +Ses (50 mg x kg(-1)) group and the MCT + Ses (100 mg x kg(-1)) group, with 12 rats in each group. The PH rat model was induced through the subcutaneous injection with MCT(60 mg x kg(-1)). After the administration for four weeks, efforts were made to measure the right ventricular systolic pressure( RVSP) and mean pulmonary artery pressure (mPAP) through right jugular vein catheterization, and isolate right ventricle( RV) and left ventricle( LV) +septum (S) and measure their length to calculate RV/ ( LV + S) and ratio of RV to tibial length. Pathologic changes in arterioles were observed by HE staining. Masson's trichrome stain was used to demonstrate changes in collagen deposition of arterioles. The alpha-smooth muscle actin (alpha-SMA) expression in pulmonary arteries was measured by immunohistochemisty. The total antioxidative capacity (T-AOC) and malondialdehyde (MDA) content in pulmonary arteries were determined by the colorimetric method. The protein expressions of collagen I, NOX2 and NOX4 were analyzed by Real-time PCR and Western blot.

RESULTAfter the administration for 4 weeks, Ses could attenuate RVSP and mPAP induced by MCT, RV/ (LV + S) and ratio of RV to Tibial length, alpha-SMA and collagen I expressions and remodeling of pulmonary vessels and right ventricle. Meanwhile, Ses could obviously inhibit the expressions of NOX2, NOX4 and MDA content and increase T-AOC.

CONCLUSIONSesamin could ameliorate pulmonary vascular remodeling induced by monocrotaline in PH rats. Its mechanism may be related to expressions of NOX2 and NOX4 expression and reduction in oxidative stress injury.

Animals ; Dioxoles ; administration & dosage ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Hypertension, Pulmonary ; drug therapy ; enzymology ; genetics ; physiopathology ; Lignans ; administration & dosage ; Lung ; blood supply ; enzymology ; metabolism ; Male ; Membrane Glycoproteins ; genetics ; metabolism ; Monocrotaline ; adverse effects ; NADPH Oxidase 2 ; NADPH Oxidase 4 ; NADPH Oxidases ; genetics ; metabolism ; Pulmonary Artery ; drug effects ; metabolism ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Vascular Remodeling ; drug effects

The aim of the present study was to evaluate the protective effect of catalpol on vascular endothelial function in STZ-induced type 2 diabetes mellitus (T2DM) rats. 40 high-fat diet with STZ-induced diabetes rats were randomly divided into model group, catalpol low-dose, middle-dose and high-dose group (10, 50, 100 mg x kg(-1) x d(-1)), 10 normal Wistar rats were used as the normal group. The normal and model groups were given an equivalent amount of saline. All reagents were administered by oral gavage for 6 weeks. After 6 weeks, blood glucose and lipids were detected by an automatic biochemical analyzer. The endothelium-dependent vasodilation response of thoracic aortar was detected. The pathological changes of the thoracic aorta were observed by HE staining. Ser- um nitric oxide (NO), 8-iso prostaglandin F2α (8-iso-PGF2α) and superoxide dismutase (SOD) were detected by ELISA. Reactive oxygen species (ROS) level of thoracic aorta was detected by fluorescence method. The expression of Nox4 and p22phox mRNA and protein in aortic tissue were detected by RT-PCR and Western-blot respectively. After catalpol treatment, endothelial damage of thoracic aorta was attenuated significantly; ROS level of thoracic aorta and serum level of 8-iso-PGF2α were decreased significantly; serum NO and SOD levels were remarkably elevated; expression of Nox4, p22phox mRNA and protein in thoracic aorta were significantly reduced (P < 0.05). Therefore, catalpol has protective effect on endothelial of T2DM, its mechanism may be associated with the down-regulation of Nox4 and p22phox expression, inhibiting oxidative stress reaction response.
Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; pathology ; Diabetes Mellitus, Type 2 ; pathology ; Dinoprost ; analogs & derivatives ; metabolism ; Endothelium, Vascular ; drug effects ; metabolism ; pathology ; Enzyme Inhibitors ; pharmacology ; Gene Expression Regulation ; drug effects ; Iridoid Glucosides ; pharmacology ; Male ; NADPH Oxidase 4 ; NADPH Oxidases ; antagonists & inhibitors ; genetics ; metabolism ; Nitric Oxide ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism

Chronic granulomatous disease (CGD) is a rare genetic disease, which is caused by defects in the NADPH oxidase complex (gp91phox, p22phox, p40phox, p47phox, and p67phox) of phagocytes. This defect results in impaired production of superoxide anions and other reactive oxygen species (ROS), which are necessary for killing bacterial and fungal microorganisms and leads to recurrent, life-threatening bacterial and fungal infections and granulomatous inflammation. The dihydrorhodamine (DHR) flow cytometry assay is a useful diagnostic tool for CGD that can detect absent or reduced NADPH oxidase activity in stimulated phagocytes. We report a patient with X-linked CGD carrying a novel mutation of the CYBB gene whose chimerism status following hematopoietic stem cell transplantation (HSCT) has been rapidly determined using the DHR assay. The level of DHR activity correlates well with short tandem repeat PCR analysis. Considering the advantages of this simple, rapid, and cost-effective procedure, serial measurement of DHR assay would facilitate the rapid determination of a patient's engraftment status, as a supplementary monitoring tool of chimerism status following HSCT.
Base Sequence ; *Chimerism ; DNA Mutational Analysis ; Flow Cytometry ; Granulomatous Disease, Chronic/*diagnosis/*enzymology/genetics/surgery ; *Hematopoietic Stem Cell Transplantation ; Homozygote ; Humans ; Infant, Newborn ; Male ; Membrane Glycoproteins/chemistry/*genetics ; Mutation ; NADPH Oxidase/chemistry/*genetics ; Polymerase Chain Reaction ; Rhodamines/chemistry/metabolism

OBJECTIVETo screen the regulatory proteins involved in Nox1 promoter activation in a cell model of inflammation and oxidative stress.

METHODSA cell model of inflammation and oxidative stress was established by stimulating A549 cells with tumor necrosis factor-α (TNF-α). The differential proteins binding to Nox1 promoter were screened by DNA pull-down and the binding proteins were separated by 2D electrophoresis and selected according to the their differential expression levels (with over 1.5-fold changes relative to the control level). The screened proteins were finally identified by MALDI-TOF/TOF-MS.

RESULTSSeven differentially expressed protein spots (all upregulated in the cell model) were obtained, among which GLE1, DDX19A, KRT1 and KRT10 were identified by mass spectrometry.

CONCLUSIONGLE1, DDX19A, KRT1 and KRT10 participate in the activation of Nox1 promoter in TNF-α-induced A549 cells, and this result provides new insights into the biological roles of the regulatory proteins of Nox1 promoter in inflammation and oxidative stress.

Cell Line, Tumor ; DEAD-box RNA Helicases ; metabolism ; Electrophoresis, Gel, Two-Dimensional ; Humans ; Inflammation ; Keratin-1 ; metabolism ; Keratin-10 ; metabolism ; Mass Spectrometry ; NADPH Oxidase 1 ; NADPH Oxidases ; genetics ; metabolism ; Nucleocytoplasmic Transport Proteins ; metabolism ; Oxidative Stress ; Promoter Regions, Genetic ; Tumor Necrosis Factor-alpha ; adverse effects

OBJECTIVETo investigate the mechanism of Panax notoginseng saponins (PNS), an effective component extracted from Panax notoginseng, on atherosclerotic plaque angiogenesis in atherosclerosis-prone apolipoprotein E-knockout (ApoE-KO) mice fed with high-fat, high-cholesterol diet.

METHODSTwenty ApoE-KO mice were divided into two groups, the model group and the PNS group. Ten normal C57BL/6J mice were used as a control group. PNS (60 mg/kg) was orally administered daily for 12 weeks in the PNS group. The ratio of plaque area to vessel area was examined by histological staining. The tissue sample of aortic root was used to detect the CD34 and vascular endothelial growth factor (VEGF) expression areas by immunohistochemistry. The expression of VEGF and nicotinamide adenine dinucleotide phosphate oxidase subunit 4 (NOX4) were measured by reverse transcription polymerase chain reaction and Western blotting respectively.

RESULTSAfter treatment with PNS, the plaque areas were decreased (P<0.05). CD34 expressing areas and VEGF expression areas in plaques were significantly decreased (P<0.05). Meanwhile, VEGF and NOX4 mRNA expression were decreased after treatment with PNS. VEGF and NOX4 protein expression were also decreased by about 72% and 63%, respectively (P<0.01).

CONCLUSIONPNS, which decreases VEGF and NOX4 expression, could alleviate plaque angiogenesis and attenuate atherosclerosis.

Animals ; Down-Regulation ; drug effects ; genetics ; Drugs, Chinese Herbal ; pharmacology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; NADPH Oxidase 4 ; NADPH Oxidases ; genetics ; metabolism ; Neovascularization, Pathologic ; pathology ; prevention & control ; Panax notoginseng ; chemistry ; Plaque, Atherosclerotic ; pathology ; prevention & control ; Saponins ; pharmacology ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

In vascular smooth muscle cells, reactive oxygen species (ROS) were known to mediate platelet-derived growth factor (PDGF)-induced cell proliferation and NADH/NADPH oxidase is the major source of ROS. NADH/NADPH oxidase is controlled by rac1 in non-phagocytic cells. In this study, we examined whether the inhibition of rac1 by adenoviral-mediated gene transfer of a dominant negative rac1 gene product (Ad.N17rac1) could reduce the proliferation of rat aortic vascular smooth muscle cells (RASMC) stimulated by PDGF via decreasing intracellular ROS. RASMC were stimulated by PDGF (80 ng/mL) with or without N-acetylcysteine 1 mM or infected with 100 mutiplicity of infection of Ad.N17rac1. Intracellular ROS levels were measured at 12 hr using carboxyl-2', 7'-dichlorodi-hydrofluorescein diacetate confocal microscopy. At 72 hr, cellular proliferation was evaluated by cell number counting and XTT assay. Compared with control, ROS levels were increased by 2-folds by PDGF. NAC and Ad.N17rac1 inhibited PDGF-induced increase of ROS by 77% and 65%, respectively. Cell number was increased by PDGF by 1.6-folds compared with control. NAC and Ad.N17rac1 inhibited PDGF-induced cellular growth by 45% and 87%, respectively. XTT assay also showed similar results. We concluded that inhibition of rac1 in RASMCs could reduce intracellular ROS levels and cellular proliferation induced by PDGF.
Adenoviridae/genetics ; Animal ; Aorta, Thoracic/cytology ; Cell Division/drug effects/physiology ; Cells, Cultured ; Gene Expression/physiology ; Gene Transfer Techniques ; Multienzyme Complexes/antagonists & inhibitors ; Muscle, Smooth, Vascular/*cytology/*metabolism ; NADH, NADPH Oxidoreductases/antagonists & inhibitors ; NADPH Oxidase/antagonists & inhibitors ; Platelet-Derived Growth Factor/*pharmacology ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species/*metabolism ; rac1 GTP-Binding Protein/*genetics/metabolism

OBJECTIVETo study the protective effect of epalrestat against endothelial cell injuries induced by high glucose.

METHODSHuman umbilical vein endothelial cells were pretreated with epalrestat (0.1 µmol/L) for 30 min followed by exposure to high glucose for 8 h. NO concentration in the cell culture supernatant was assayed using chemiluminescence method following the exposure. Real-time PCR and Western blotting were used to detect eNOS mRNA and protein expression levels and the protein expressions of AR gene (the target gene of epalrestat) and NOX4 (the upstream gene of NO).

RESULTSCompared with mannitol treatment, an 8-h exposure to high glucose caused significantly decreased NO levels and eNOS mRNA and protein expression in the vascular endothelial cells (P<0.05). Pretreatment with epalrestat prior to high glucose exposure resulted in elevated eNOS mRNA and protein expression levels and NO up-regulation in the cell culture as compared with the glucose exposure alone group (P<0.05), causing also decreased expression of AR and NOX4 in the cells.

CONCLUSIONSHigh glucose can induce endothelial cell damage characterized by a lowered level of NO secretion. Epalrestat can protect the endothelial cells against high glucose-induced injury by inhibiting the expression of AR and NOX4.

Aldehyde Reductase ; antagonists & inhibitors ; Cells, Cultured ; Endothelium, Vascular ; drug effects ; metabolism ; Enzyme Inhibitors ; pharmacology ; Glucose ; adverse effects ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; Humans ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; RNA, Messenger ; genetics ; Rhodanine ; analogs & derivatives ; pharmacology ; Thiazolidines ; pharmacology

The aim of the present study is to investigate how cytochrome P450 enzymes (CYP) 2C8-derived epoxyeicosatrienoic acids (EETs) regulate the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and protect against oxidative stress-induced endothelial injuries in the development and progression of atherosclerosis. In this study, cultured human umbilical vein endothelial cells (HUVECs) were transfected with CYP2C8 or pretreated with exogenous EETs (1 μmol/L) before TNF-α (20 ng/mL) stimulation. Apoptosis and intracellular ROS production were determined by flow cytometry. The expression levels of ROS-associated NAD(P)H subunits gp91 and p47, the anti-oxidative enzyme catalase (CAT), Nrf2, heme oxygenase-1 (HO-1) and endothelial nitric oxide synthase (eNOS) were detected by Western blotting. The results showed that CYP2C8-derived EETs decreased apoptosis of HUVECs treated with TNF-α. Pretreatment with 11, 12-EET also significantly blocked TNF-α-induced ROS production. In addition, 11, 12-EET decreased oxidative stress-induced apoptosis. Furthermore, the ability of 11, 12-EET to protect cells against TNF-α-induced apoptosis via oxidative stress was abrogated by transient transfection with Nrf2-specific small interfering RNA (siRNA). In conclusion, CYP2C8-derived EETs prevented TNF-α-induced HUVECs apoptosis via inhibition of oxidative stress associated with the Nrf2 signaling.
8,11,14-Eicosatrienoic Acid ; analogs & derivatives ; metabolism ; pharmacology ; Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Apoptosis ; drug effects ; Aryl Hydrocarbon Hydroxylases ; genetics ; metabolism ; Atherosclerosis ; genetics ; metabolism ; pathology ; Catalase ; genetics ; metabolism ; Cytochrome P-450 CYP2C8 ; genetics ; metabolism ; Gene Expression Regulation ; Heme Oxygenase-1 ; genetics ; metabolism ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; metabolism ; Humans ; Membrane Glycoproteins ; genetics ; metabolism ; Models, Biological ; NADPH Oxidase 2 ; NADPH Oxidases ; genetics ; metabolism ; NF-E2-Related Factor 2 ; antagonists & inhibitors ; genetics ; metabolism ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; metabolism ; Reactive Oxygen Species ; antagonists & inhibitors ; metabolism ; Signal Transduction ; Tumor Necrosis Factor-alpha ; metabolism ; pharmacology