Oxidative stress in granulosa cells contributes to poor oocyte quality and IVF-ET outcomes in women with polycystic ovary syndrome / 医学前沿

The increased levels of intracellular reactive oxygen species (ROS) in granulosa cells (GCs) may affect the pregnancy results in women with polycystic ovary syndrome (PCOS). In this study, we compared the in vitro fertilization and embryo transfer (IVF-ET) results of 22 patients with PCOS and 25 patients with tubal factor infertility and detected the ROS levels in the GCs of these two groups. Results showed that the PCOS group had significantly larger follicles on the administration day for human chorionic gonadotropin than the tubal factor group (P 0.05). PCOS group had slightly lower fertilization, cleavage, grade I/II embryo, clinical pregnancy, and implantation rates and higher miscarriage rate than the tubal factor group (P > 0.05). We further found a significantly higher ROS level of GCs in the PCOS group than in the tubal factor group (P < 0.05). The increased ROS levels in GCs caused GC apoptosis, whereas NADPH oxidase 2 (NOX2) specific inhibitors (diphenyleneiodonium and apocynin) significantly reduced the ROS production in the PCOS group. In conclusion, the increased ROS expression levels in PCOS GCs greatly induced cell apoptosis, which further affected the oocyte quality and reduced the positive IVF-ET pregnancy results of women with PCOS. NADPH oxidase pathway may be involved in the mechanism of ROS production in GCs of women with PCOS.

Light curing resin cements containing iodonium salts promote suitable apical bonding of posts to radicular dentin

Abstract The aim of this study was to analyze the efficiency of experimental light-curing resin cements (ERCs) with a ternary photo-initiator system containing diphenyliodonium hexafluorphosphate (DPI) and different amines on retention of glass-fiber posts to dentin (GFP). ERCs formulations: a 1:1 mass ratio of 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenylpropane and triethyleneglycol dimethacrylate. Camphorquinone was used as initiator. Six experimental groups were established according to the amine used: [ethyl-4-(dimethylamino)benzoate-EDMAB or 2-(dimethylamino)ethyl methacrylate-DMAEMA] and the concentration of DPI (0, 0.5 mol%, 1 mol%). The resin cements Variolink II (dual- and light-cured versions) were used as commercial reference. Eighty recently extracted bovine incisors (n = 10) were selected for this study. The roots were prepared and the fiber posts were cemented with the resin cement specified for each experimental group. Specimens from coronal, middle, and apical thirds of the root were subjected to push-out bond strength test 24 hours after bonding. Data were subjected to split-plot ANOVA and the Tukey test (p = 0.05). ERCs containing DPI showed statistically significant higher bond strengths compared with ERCs without DPI. ERCs containing DPI were statistically similar to VARIOLINK II - dual-cured and superior to VARIOLINK II - light-cured (except for EDMAB - 1DPI in the medium third and DMAEMA - 1DPI in the coronal third). Different amines did not influence post retention. The apical root region showed the lowest bond strength for the groups EDAB-0DPI, DMAEMA-0DPI and VARIOLINK II light-cured. Light-cured ERCs containing DPI were efficient for GFP retention to radicular dentin, with similar behaviour to that of dual-curing commercial resin cement.

Diphenyleneiodonium Inhibits Apoptotic Cell Death of Gastric Epithelial Cells Infected with Helicobacter pylori in a Korean Isolate

NADPH oxidase produces a large amount of reactive oxygen species (ROS) in Helicobacter pylori (H. pylori)-induced gastric epithelial cells. Even though ROS mediate apoptotic cell death, direct involvement of NADPH oxidase on H. pylori-induced apoptosis remains unclear. Besides, H. pylori isolates show a high degree of genetic variability. The predominant genotype of H. pylori in Korea has been reported as cagA+, vacA s1b, m2, iceA genotype. Present study aims to investigate whether NADPH oxidase-generated ROS mediate apoptosis in human gastric epithelial AGS cells infected with H. pylori in a Korean isolate. AGS cells were pretreated with or without an NADPH oxidase inhibitor diphenyleneiodonium (DPI) and cultured in the presence of H. pylori at a bacterium/cell ratio of 300:1. Cell viability, hydrogen peroxide level, DNA fragmentation, and protein levels of p53, Bcl-2, and Bax were determined. Results showed that H. pylori inhibited cell viability with the density of H. pylori added to the cells. Inhibition of NADPH oxidase by DPI suppressed H. pylori-induced cell death, increased hydrogen peroxide, DNA fragmentation, and the ratio of Bax/Bcl-2, and p53 induction in AGS cells dose-dependently. The results suggest that targeting NADPH oxidase may prevent the development of gastric inflammation associated with H. pylori infection by suppressing abnormal apoptotic cell death of gastric epithelial cells.

Research on the mechanism and regulation of overtraining-related the function of neutrophils by the inhibitor of NADPH oxidase and glutamine supplementation / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the method and mechanism for exercise-related immunosuppression via the inhibitor of NADPH oxidase diphenyleneiodonium(DPI) and glutamine supplementation and on the function of neutrophils after overtraining.</p><p><b>METHODS</b>Fifty male Wistar rats were randomly divided into five groups: a negative control group (C), an overtraining group (E), an overtraining + DPI intervention group (D), an overtraining+ glutamine supplementation group(G) and combined glutamine + DPI intervention group(DG). After 36 - 40 h from the last training, eight rats were randomly selected from each group, and blood was sampled from the orbital vein. ELISAs were used to measure serum cytokine levels and lipid peroxidation in blood plasma. Flow cytometry was used to measure neutrophil respiratory burst and phagocytosis. The activity of NADPH oxidase was assessed by chemiluminescence and the gene expression of gp91(phox) and p47(phox) of the NADPH-oxidase subunit was checked by Western blot.</p><p><b>RESULTS</b>Compared with group C, the plasma concentrations of NO increased in group G, and the NO, cytokine-induced neutrophil chemoattractant (CINC) concentrations in group DG increased significantly. The respiratory burst and phagocytosis function of neutrophils were decreased in group E, but in group DG were increased when compared with those of group E. After overtraining the expression of gp91(phox) and p47(phox) was up regulated in group E. There were no significant changes in other groups except group DG, in which the expression of gp91(phox) was down regulated. Compared with group E, the expression of gp91(phox) and p47(phox) was up regulated in group D, group G and group DG.</p><p><b>CONCLUSION</b>The activation of NADPH oxidase is responsible for the production of superoxide anions, which may be related to the decrease in neutrophil function after over training and is the mechanism of exercise-related immunosuppression. The DPI treatment combined glutamine supplementation can reverse the decrease neutrophils function after overtraining in vitro.</p>

Extracellular Nucleotides Can Induce Chemokine (C-C motif) Ligand 2 Expression in Human Vascular Smooth Muscle Cells

To understand the roles of purinergic receptors and cellular molecules below the receptors in the vascular inflammatory response, we determined if extracellular nucleotides up-regulated chemokine expression in vascular smooth muscle cells (VSMCs). Human aortic smooth muscle cells (AoSMCs) abundantly express P2Y1, P2Y6, and P2Y11 receptors, which all respond to extracellular nucleotides. Exposure of human AoSMCs to NAD+ , an agonist of the human P2Y11 receptor, and NADP+ as well as ATP, an agonist for P2Y1 and P2Y11 receptors, caused increase in chemokine (C-C motif) ligand 2 gene (CCL2) transcript and CCL2 release; however, UPT did not affect CCL2 expression. CCL2 release by NAD+ and NADP+ was inhibited by a concentration dependent manner by suramin, an antagonist of P2-purinergic receptors. NAD+ and NADP+ activated protein kinase C and enhanced phosphorylation of mitogen-activated protein kinases and Akt. NAD(+)- and NADP(+)-mediated CCL2 release was significantly attenuated by SP6001250, U0126, LY294002, Akt inhibitor IV, RO318220, GF109203X, and diphenyleneiodium chloride. These results indicate that extracellular nucleotides can promote the proinflammatory VSMC phenotype by up-regulating CCL2 expression, and that multiple cellular elements, including phosphatidylinositol 3-kinase, Akt, protein kinase C, and mitogen-activated protein kinases, are involved in that process.

The Protective Effect of Quercetin-3-O-beta-D-Glucuronopyranoside on Ethanol-induced Damage in Cultured Feline Esophageal Epithelial Cells

Quercetin-3-O-beta-D-glucuronopyranoside (QGC) is a flavonoid glucoside extracted from Rumex Aquaticus Herba. We aimed to explore its protective effect against ethanol-induced cell damage and the mechanism involved in the effect in feline esophageal epithelial cells (EEC). Cell viability was tested and 2',7'-dichlorofluorescin diacetate assay was used to detect intracellular H2O2 production. Western blotting analysis was performed to investigate MAPK activation and interleukin 6 (IL-6) expression. Exposure of cells to 10% ethanol time-dependently decreased cell viability. Notably, exposure to ethanol for 30 min decreased cell viability to 43.4%. When cells were incubated with 50 microM QGC for 12 h prior to and during ethanol treatment, cell viability was increased to 65%. QGC also inhibited the H2O2 production and activation of ERK 1/2 induced by ethanol. Pretreatment of cells with the NADPH oxidase inhibitor, diphenylene iodonium, also inhibited the ethanol-induced ERK 1/2 activation. Treatment of cells with ethanol for 30 or 60 min in the absence or presence of QGC exhibited no changes in the IL-6 expression or release compared to control. Taken together, the data indicate that the cytoprotective effect of QGC against ethanol-induced cell damage may involve inhibition of ROS generation and downstream activation of the ERK 1/2 in feline EEC.

Angiotensin II stimulates MCP-1 production in rat glomerular endothelial cells via NAD(P)H oxidase-dependent nuclear factor-kappa B signaling

Angiotensin II (Ang II) plays a crucial role in the pathogenesis of renal diseases. The objective of the present study was to investigate the possible inflammatory effect of Ang II on glomerular endothelial cells and the underlying mechanism. We isolated and characterized primary cultures of rat glomerular endothelial cells (GECs) and observed that Ang II induced the synthesis of monocyte chemoattractant protein-1 (MCP-1) in GECs as demonstrated by Western blot. Ang II stimulation, at concentrations ranging from 0.1 to 10 µm, of rat GECs induced a rapid increase in the generation of reactive oxygen species as indicated by laser fluoroscopy. The level of p47phox protein, an NAD(P)H oxidase subunit, was also increased by Ang II treatment. These effects of Ang II on GECs were all reduced by diphenyleneiodonium (1.0 µm), an NAD(P)H oxidase inhibitor. Ang II stimulation also promoted the activation of nuclear factor-kappa B (NF-κB). Telmisartan (1.0 µm), an AT1 receptor blocker, blocked all the effects of Ang II on rat GECs. These data suggest that the inhibition of NAD(P)H oxidase-dependent NF-κB signaling reduces the increase in MCP-1 production by GECs induced by Ang II. This may provide a mechanistic basis for the benefits of selective AT1 blockade in dealing with chronic renal disease.

NADPH oxidase-derived reactive oxygen species involved in angiotensin II-induced monocyte chemoattractant protein-1 expression in mesangial cells / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the origin of oxidative stress induced by angiotensin II (AngII) in human mesangial cells and the role of reactive oxygen species (ROS) in AngII-induced monocyte chemoattractant protein-1 (MCP-1) expression.</p><p><b>METHODS</b>MCP-1 expression was determined by real time RT-PCR. ROS production was measured by DCFDA fluorescence. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity was examined by lucigenin chemiluminescence. p47phox and p67phox translocation was assayed by Western blot. Twenty-four male mice were randomly divided into three groups: the control, the AngIIinfusion [AngII 400 ng/(kg.min)], and the apocynin treatment. AngII was infused by subcutaneously osmotic minipump for 14 days. Urinary albumin and 8-isoprostane excretion were measured by ELISA.</p><p><b>RESULTS</b>In cultured human mesangial cells, AngII induced the MCP-1 expression in a dose-dependent manner with 3.56 fold increase as compared with the control. AngII increased intracellular ROS production as early as 3 min with the peak at 60 min and was in a time and dose-dependent. Incubation with different dosages of AngII (1 nmol/L, 10 nmol/L, and 100 nmol/L AngII) for 60 min, ROS production increased at 1.82, 2.92, and 4.08 folds respectively. AngII-induced ROS generation was sensitive to diphenyleneiodonium sulfate (DPI, 10 micromol/L) and apocynin (500 micromol/L), two structurally distinct NADPH oxidase inhibitors. In contrast, inhibitors of other oxidant-producing enzymes, including the mitochondrial complex Iinhibitor rotenone, the xanthine oxidase inhibitor allopurinol, the cyclooxygenase inhibitor indomethacin, the lipoxygenase inhibitor nordihydroguiaretic acid, the cytochrome P450 oxygenase inhibitor ketoconazole and the nitric oxide synthase inhibitor G-nitro-L-arginine methyl ester were without an effect. AngII-induced ROS generation was inhibited by the AT1 antagonist losartan (10 micromol/L) but not the AT2 antagonist PD123319 (10 micromol/L). AngII treatment induced translocation of cytosolic of p47phox and p67phox to the membrane. The antioxidants almost abolished AngII-induced MCP-1 expression. AngII infusion increased urinary and p67 translocation by 2.69-, 2.97-, and 2.67-fold, respectively.</p><p><b>CONCLUSIONS</b>NADPH oxidase-derived ROS is involved in AngII-induced MCP-1 expression. Inhibition of NADPH oxidase alleviates AngII-induced renal injury.</p>

Mycobacterium tuberculosis Induces the Production of Tumor Necrosis Factor-alpha, Interleukin-6, and CXCL8 in Pulmonary Epithelial Cells Through Reactive Oxygen Species-dependent Mitogen-activated Protein Kinase Activation

Upon contact with airway epithelial cells, mycobacteria activate several signal transduction events that are required for induction of inflammatory cytokines/chemokines. In this study, we found that Mycobacterium tuberculosis (Mtb)induced reactive oxygen species (ROS) production is essential for the expression of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and CXC-chemokine ligand (CXCL) 8 through the activation of mitogen-activated protein kinases [MAPKs; extracellular signal-regulated kinase (ERK) 1/2 and p38 MAPK] in A549 cells representing alveolar epithelial cells. We observed that Mtb rapidly enhanced ROS production after stimulation in a toll-like receptor (TLR) 2-dependent manner. In addition, Mtb triggered ERK1/2 and p38 MAPK signaling pathways which were dependent on ROS generation in A549 cells. Moreover, Mtb stimulation significantly increased the secretion of TNF-alpha, IL-6, and CXCL8 over that in untreated controls. Pretreatment of A549 cells with the antioxidant, N-acetylcysteine and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, diphenylene iodonium, substantially inhibited Mtb-induced production of TNF-alpha, IL-6, and CXCL8. Studies using inhibitors selective for ERK1/2 and p38 MAPK pathways showed that both pathways play an essential role in the induction of TNF-alpha, IL-6, and CXCL8 at transcriptional levels in A549 cells. Collectively, our findings indicate the critical role of TLR2-dependent ROS in the Mtb-induced inflammatory cytokine/chemokine production in alveolar epithelial cells through MAPK-dependent signaling pathways.

Effects of diphenyliodonium on the degree of conversion and the compressive strength of composite resin / 生物医学工程学杂志

The degree of conversion (DC) and the compressive strength (CS) are important indexes of composite resin. This study is aimed to investigate the effects of diphenyliodonium on the DC and the CS of the light-curing composite resin. Different amount of diphenyliodonium hexaflourophosphate was added to the light-curing composite resin; the concentrations of diphenyliodonium hexaflourophosphate were 0 wt%, 0.5 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt% and 4.0 wt% of the reisin matrix (containing BisS-GMA and TEGDMA) respectively. The DC and the CS of the six aforementioned groups of the composite resin were measured by the Fourier transform infrared spectroscopy and the tensile strength of machine, respectively. Diphenyliodonium hexaflourophosphate can improve the DC and CS of the light-curing composite resin. When the concentration is 2.0 wt%, the DC and CS can achieve better performance.

The Production and Functions of Reactive Oxygen Species in Mouse Bone Marrow-derived Dendritic Cells by Various Haptens and Irritants / 대한피부과학회지

BACKGROUND: Various allergens and irritants induced the production of reactive oxygen species (ROS) in the well-established mouse dendritic cell (DC) line XS106 and this production of ROS was inhibited by antioxidants. OBJECTIVE: To investigate the production and functions of ROS in mouse bone marrow-derived DCs (BM-DCs) by various haptens and irritants, we examined the production of ROS, the expression of surface molecules, and the production of interleukin-12 (IL-12) in mouse BM-DCs. METHODS: Six to eight-week-old female C57/BL6 mice were used in this study. Mouse BM-DCs were co-cultured with DNFB, DNCB, TNBS, hydroquinone, NiSO4, CoCl2, MnCl2, thimerosal, SDS, and BKC. The production of ROS and the expression of surface molecules (CD40, CD80, CD86, and MHC-II) were measured by flow cytometry in chemical-treated mouse BM-DCs. In addition, the cells were pretreated with antioxidants to determine whether the production of ROS can be inhibited. The production of IL-12 was also measured in DNCB and SDS-treated mouse BM-DCs using ELISA. Results: The production of ROS in mouse BM-DCs was induced by various allergens, including DNFB, DNCB, TNBS, hydroquinone, MnCl2 and irritants like SDS, BKC. The expression of surface molecules was induced by various chemicals and NiSO4 was the most potent inducer of surface molecules in mouse BM-DCs. The production of ROS in DNCB and SDS-treated mouse BM-DCs was partially inhibited by diphenylene iodonium, but not by rotenone, vitamin E, allopurinol, glutathione. The production of IL-12 was not detected in DNCB and SDS-treated mouse BM-DCs. CONCLUSION: The production of ROS was induced in mouse BM-DCs by various allergens and irritants. The expression of surface molecules was also induced by various chemicals. The production of ROS was partially inhibited by DPI. The production of IL-12 was not detected.

Migration of Vascular Smooth Muscle Cells by High Glucose is Reactive Oxygen Dependent / 당뇨병

BACKGROUND: Oxidative stress contributes to vascular diseases in patients with diabetes. As the mechanism of development and progression of diabetic vascular complications is poorly understood, this study was aimed to assess the potential role of hyperglycemia-induced oxidative stress and to determine whether the oxidative stress is a major factor in hyperglycemia-induced migration of vascular smooth muscle cells (VSMCs). METHODS: We treated primary cultured rat aortic smooth muscle cells for 72 hours with medium containing 5.5 mM D-glucose (normal glucose), 30 mM D-glucose (high glucose) or 5.5 mM D-glucose plus 24.5 mM mannitol (osmotic control). We measured the migration of VSMCs and superoxide production. Immunoblotting of PKC isozymes using phoshospecific antibodies was performed, and PKC activity was also measured. RESULTS: Migration of VSMCs incubated under high glucose condition were markedly increased compared to normal glucose condition. Treatment with diphenyleneiodonium (DPI, 10 micromol/L) and superoxide dismutase (SOD, 500 U/mL) significantly suppressed high glucose-induced migration of VSMCs. Superoxide production was significantly increased in high glucose condition and was markedly decreased after treatment with DPI and SOD. High glucose also markedly increased activity of PKC-delta isozyme. When VSMCs were treated with rottlerin or transfected with PKC-delta siRNA, nitro blue tetrazolium (NBT) staining and NAD(P)H oxidase activity were significantly attenuated in the high glucose-treated VSMCs. Furthermore, inhibition of PKC-delta markedly decreased VSMC migration by high glucose. CONCLUSION: These results suggest that high glucose-induced VSMC migration is dependent upon activation of PKC-delta, which may responsible for elevated intracellular ROS production in VSMCs, and this is mediated by NAD(P)H oxidase.

novel ring-expansion of thiochroman-4-one sulfonium methanides to tetrahydro-1-benzothiepin-5-ones

Heating thiochroman-4-ones with dimethyl diazomalonate in refluxing toluene in presence of copper sulphate gave the corresponding bismetho-xycarbonylmethanides [4] and ring-expansion product 2, 3, 4, 5-tetrahydro-1-benzothienpin-5-ones [5]. Treatment of [4] with triethylamine afforded ring-expansion product [5]