The purpose of the present study was to determine the effects of resveratrol on hypoxia-induced oxidative stress and proliferation in pulmonary artery smooth muscle cells (PASMCs) and the underlying mechanism. Primary rat PASMCs were isolated and cultured in vitro and pretreated with different concentrations of resveratrol (10, 20, and 40 µmol/L) or the NADPH oxidase (NOX) inhibitor VAS2870 (10 µmol/L) for 0.5 h. The cells were then cultured under normoxia (21% O
Animals ; Cell Proliferation ; Cells, Cultured ; Hypoxia ; Myocytes, Smooth Muscle ; NADPH Oxidase 4 ; Oxidative Stress ; Pulmonary Artery ; Rats ; Reactive Oxygen Species ; Resveratrol/pharmacology* ; Signal Transduction

BACKGROUND: Chronic exposure to elevated levels of free fatty acids contributes to pancreatic β-cell dysfunction. Although it is well known that metformin induces cellular energy depletion and a concomitant activation of AMP-activated protein kinase (AMPK) through inhibition of the respiratory chain, previous studies have shown inconsistent results with regard to the action of metformin on pancreatic β-cells. We therefore examined the effects of metformin on pancreatic β-cells under lipotoxic stress.METHODS: NIT-1 cells and mouse islets were exposed to palmitate and treated with 0.05 and 0.5 mM metformin. Cell viability, glucose-stimulated insulin secretion, cellular adenosine triphosphate, reactive oxygen species (ROS) levels and Rho kinase (ROCK) activities were measured. The phosphorylation of AMPK was evaluated by Western blot analysis and mRNA levels of endoplasmic reticulum (ER) stress markers and NADPH oxidase (NOX) were measured by real-time quantitative polymerase chain reaction analysis.RESULTS: We found that metformin has protective effects on palmitate-induced β-cell dysfunction. Metformin at a concentration of 0.05 mM inhibits NOX and suppresses the palmitate-induced elevation of ER stress markers and ROS levels in a AMPK-independent manner, whereas 0.5 mM metformin inhibits ROCK activity and activates AMPK.CONCLUSION: This study suggests that the action of metformin on β-cell lipotoxicity was implemented by different molecular pathways depending on its concentration. Metformin at a usual therapeutic dose is supposed to alleviate lipotoxic β-cell dysfunction through inhibition of oxidative stress and ER stress.
Adenosine Triphosphate ; AMP-Activated Protein Kinases ; Animals ; Blotting, Western ; Cell Survival ; Electron Transport ; Endoplasmic Reticulum ; Endoplasmic Reticulum Stress ; Fatty Acids, Nonesterified ; Insulin ; Insulin-Secreting Cells ; Metformin ; Mice ; NADPH Oxidase ; Oxidative Stress ; Phosphorylation ; Polymerase Chain Reaction ; Reactive Oxygen Species ; rho-Associated Kinases ; RNA, Messenger

OBJECTIVE: To investigate the effects of 1,25-dihydroxyvitamin D3 (1,25-VitD3) supplementation on cerebral injury after ischemia/reperfusion (I/R) in mice with middle cerebral artery occlusion (MCAO). METHODS: Male C57BL6 mice were randomly divided into Sham group, Vehicle group and 1,25-VitD3 group, with 10 mice in each group. Vehicle group and 1,25-VitD3 group were given MCAO for 1 hour, and then killed after reperfusion for 24 hours. Mice in 1,25-VitD3 group were treated with 1,25-VitD3 at the dose of 100 ng/(kg·d) by injected intraperitoneally for 5 days before MCAO operation. Cerebral ischemic penumbra areas of each group were collected for TTC staining, RT-PCR, TTC staining and immunohistochemistry assay. The function defect of mice was evaluated by using neurological function score. RESULTS: Compared with the sham group, the volume of cerebral infarction in Vehicle group was increased significantly, and the expressions of IL-6, IL-1beta and Gp91phox in brain tissues were increased significantly (P＜0.05); compared with Vehicle group, supplementation of 1,25-VitD3 reduced the volume of cerebral infarction by about 50% in I/R mice (P＜0.05), and the expressions of IL-6, IL-1beta and Gp91phox in brain tissues of 1,25-VitD3 group were decreased significantly (P＜0.05). The expression of Foxp3, a T-regulatory cell marker, was significantly increased in the brain of mice (P＜0.05), while the expression of Rorc, a transcription factor, was significantly decreased (P＜0.05), suggesting that Th17/gamma Delta T-cell response was reduced and the number of neutrophils in the brain injury site of mice was significantly reduced (P＜0.05). CONCLUSION Vitamin D could alleviate the development of cerebral infarction after arterial occlusion (MCAO) reperfusion, and its mechanism may be through regulating the inflammatory response in mouse brain I/R.
Animals ; Brain ; Cytokines ; metabolism ; Infarction, Middle Cerebral Artery ; drug therapy ; Inflammation ; Male ; Mice ; Mice, Inbred C57BL ; NADPH Oxidase 2 ; metabolism ; Protective Agents ; pharmacology ; Random Allocation ; Rats, Sprague-Dawley ; Reperfusion Injury ; drug therapy ; T-Lymphocytes ; Th17 Cells ; Vitamin D ; pharmacology

OBJECTIVE: To investigate the mechanism of high glucose affecting the apoptosis of schwann cells through Nox4 NADPH oxidase. METHODS: The schwann cells of newborn Wistar rats were cultured in vitro. The cultured cells were divided into four groups: control group, high-glucose group, NOX4 siRNA group and control siRNA group (n=10). The WST-1 method was used to detect the cell vitality, and the DCFH-DA method was used to detect the contents of intracellular reactive oxygen free radicals (ROS). Nox4 and Caspase3 mRNA expressions were detected by real-time fluorescence quantitative RT-PCR. Nox4 and Caspase3 protein expressions were determined by Western blot. RESULTS: High glucose culture up-regulated Nox4 mRNA and protein expressions of schwann cells, decreased activity of schwann cells, increased intracellular ROS content, and promoted apoptosis by increasing Caspase3 mRNA and protein expressions. NOX4 siRNA blocked the accumulation of ROS in the high glucose cultured schwann cells, and reduced the damage of glucose on cell viability, by inhibiting NOX4 gene expression. NOX4 siRNA also reduced cell apoptosis by down-regulating Caspase3 mRNA and protein expressions. CONCLUSION Nox4 was involved in the hyperglycemic-induced apoptosis of schwann cells through ROS. The regulation of Nox4 expression or function might be a new way to treat diabetic peripheral neuropathy.
Animals ; Apoptosis ; Caspase 3 ; metabolism ; Cells, Cultured ; Culture Media ; Glucose ; NADPH Oxidase 4 ; metabolism ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; metabolism ; Schwann Cells ; cytology ; metabolism

BACKGROUND AND OBJECTIVES: Elevated endothelin (ET)-1 level is strongly correlated with the pathogenesis of pulmonary arterial hypertension (PAH). Expression level of nicotinamide adenine dinucleotide phosphate oxidase (NOX) 4 is increased in the PAH patients. Ambrisentan, a selective endothelin receptor A (ERA) antagonist, is widely used in PAH therapy. The current study was undertaken to evaluate the effects of ambrisentan treatment in the monocrotaline (MCT)-induced PAH rat model. METHODS: Rats were categorized into control group (C), monocrotaline group (M) and ambrisentan group (Am). The M and Am were subcutaneously injected 60 mg/kg MCT at day 0, and in Am, ambrisentan was orally administered the day after MCT injection for 4 weeks. The right ventricle (RV) pressure was measured and pathological changes of the lung tissues were observed by Victoria blue staining. Protein expressions of ET-1, ERA, endothelial nitric oxide synthase (eNOS) and NOX4 were confirmed by western blot analysis. RESULTS: Ambrisentan treatment resulted in a recovery of the body weight and RV/left ventricle+septum at week 4. The RV pressure was lowered at weeks 2 and 4 after ambrisentan administration. Medial wall thickening of pulmonary arterioles and the number of intra-acinar arteries were also attenuated by ambrisentan at week 4. Protein expression levels of ET-1 and eNOS were recovered at weeks 2 and 4, and ERA levels recovered at week 4. CONCLUSIONS: Ambrisentan administration resulted in the recovery of ET-1, ERA and eNOS protein expression levels in the PAH model. However, the expression level of NOX4 remained unaffected after ambrisentan treatment.
Animals ; Arteries ; Arterioles ; Blotting, Western ; Body Weight ; Endothelin Receptor Antagonists ; Endothelins ; Gene Expression ; Heart Ventricles ; Humans ; Hypertension ; Hypertension, Pulmonary ; Lung ; Models, Animal ; Monocrotaline ; NADP ; NADPH Oxidase ; Nitric Oxide Synthase Type III ; Oxidoreductases ; Rats ; Receptors, Endothelin ; Victoria

Many of the fungicides and antibiotics currently available against plant pathogens are of limited use due to the emergence of resistant strains. In this study, we examined the effects of diphenyleneiodonium chloride (DPIC), an inhibitor of the superoxide producing enzyme NADPH oxidase, against fungal and bacterial plant pathogens. We found that DPIC inhibits fungal spore germination and bacterial cell proliferation. In addition, we demonstrated the potent antibacterial activity of DPIC using rice heads infected with the bacterial pathogen Burkholderia glumae which causes bacterial panicle blight (BPB). We found that treatment with DPIC reduced BPB when applied during the initial flowering stage of the rice heads. These results suggest that DPIC could serve as a new and useful antimicrobial agent in agriculture.
Agriculture ; Anti-Bacterial Agents ; Burkholderia ; Cell Proliferation ; Flowers ; Germination ; Head ; NADPH Oxidase ; Plants ; Spores, Fungal ; Superoxides

BACKGROUND AND OBJECTIVES: Patients suffer from long-term diabetes can result in severe complications in multiple organs through induction of vascular dysfunctions. However, the effects of chronic hyperglycemic conditions on hematopoiesis and the microenvironment in the bone marrow (BM) are not yet well understood. METHODS: BM cells were harvested from femurs of mice and analyzed using flow cytometry. Human PVCs were cultured in serum-free α-MEM. After 24hrs, PVC-CM was collected and filtered through a 0.22 μm filter. RESULTS: In this study, we showed that hyperglycemia alters hematopoietic composition in the BM, which can partially be restored via paracrine mechanisms, including perivascular cells (PVCs) and NADPH oxidase (NOX) inhibition in mice with streptozotocin-induced diabetes. Prolonged hyperglycemic conditions resulted in an increase in the frequency and number of long-term hematopoietic stem cells as well as the number of total BM cells. The altered hematopoiesis in the BM was partially recovered by treatment with PVC-derived conditioned medium (CM). Long-term diabetes also increased the number of myeloid-derived suppressor cells in the BM, which was partially restored by the administration of PVC-CM and diphenyleneiodonium (DPI), a NOX inhibitor. We further showed the downregulation of ERK and p38 phosphorylation in BM cells of diabetic mice treated with PVC-CM and DPI. This may be associated with dysfunction of hematopoietic cells and promotion of subsequent diabetic complications. CONCLUSIONS: Our data suggested that alterations in BM hematopoietic composition due to prolonged hyperglycemic conditions might be restored by improvement of the hematopoietic microenvironment and modulation of NOX activity.
Animals ; Bone Marrow ; Culture Media, Conditioned ; Diabetes Complications ; Down-Regulation ; Femur ; Flow Cytometry ; Hematopoiesis ; Hematopoietic Stem Cells ; Humans ; Hyperglycemia ; Mice ; NADP ; NADPH Oxidase ; Phosphorylation

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*

Objective To verify the expressions of genes associated with colorectal cancer with hyperglycemia and evaluate their diagnostic values.Methods Tumor tissues,distal normal intestinal mucosa,and peripheral blood samples were harvested from 109 colorectal cancer patients and peripheral blood samples from 30 diabetes patients and 30 healthy volunteers. The mRNA expressions of glucose regulated protein 78 (GRP78),NADPH oxidase-1 (NOX1),carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5),heat shock protein 60 (HSP60),and histone deacetylase 1(HDAC1) were detected by real-time quantitative polymerase chain reaction. The correlation between the gene expressions and clinicopathological parameters in colorectal cancer patients were analyzed using Pearson's correlation analysis. Diagnostic test accuracy evaluation was used to calculate the sensitivity,specificity,accuracy,predictability,Youden index,and likelihood ratio of serum gene expressions in colorectal cancer patients,and the receiver operating characteristic (ROC) curves were drawn. The area under the ROC curve was calculated to evaluate the diagnostic efficiency of the combined detection of multiple genes.Results The mRNA levels of GRP78 (P=0.001),NOX1 (P=0.022),CEACAM5 (P=0.000),HSP60 (P=0.044),and HDAC1 (P=0.047) were positively correlated with the fasting blood glucose level. The mRNA expressions of NOX1 (P=0.000,P=0.008) and HDAC1 (P=0.000,P=0.037) in tissues and serum were significantly higher in colorectal cancer patients than in patients with normal blood glucose levels. The NOX1 mRNA expression was positively correlated with the diameter of colorectal cancer (P=0.013),and the HDAC1 mRNA expression was significantly correlated with the tumor site (P=0.049),depth of primary tumor invasion (P=0.025),and TNM stage (P=0.042). The areas under the ROC curves of NOX1,CEACAM5,and HDAC1 were 0.931,0.852,and 0.860 respectively (all P=0.000). The specificity,accuracy,and negative predictive value of NOX1,HDAC1 mRNA expression in colorectal cancer patients with hyperglycemia were all above 90%. The diagnostic sensitivity and specificity of the combined detection of NOX1,CEACAM5,and HDAC1 were 98.82% and 99.93%,respectively.Conclusion Combined detection of genes associated with colorectal cancer accompanied by hyperglycemia can improve the diagnostic efficiency of early screening.
Biomarkers, Tumor ; genetics ; Carcinoembryonic Antigen ; genetics ; Case-Control Studies ; Colorectal Neoplasms ; complications ; diagnosis ; genetics ; Diabetes Mellitus ; genetics ; GPI-Linked Proteins ; genetics ; Heat-Shock Proteins ; genetics ; Histone Deacetylase 1 ; genetics ; Humans ; Hyperglycemia ; complications ; diagnosis ; genetics ; NADPH Oxidase 1 ; genetics ; ROC Curve

An isoform of NADPH oxidase (NOX), NOX2 is a superoxide-generating enzyme involved in diverse pathophysiological events. Although its potential as a therapeutic target has been validated, there is no clinically available inhibitor. Herein, NOX2-inhibitory activity was screened with the constituents isolated from Schisandra chinensis, which has been reported to have antioxidant and reactive oxygen species (ROS)-scavenging effects. Among the partitions prepared from crude methanolic extract, a chloroform-soluble partition showed the highest NOX2-inhibitory activity in PLB-985 cell-based NOX2 assay. A total of twenty nine compounds (1 – 29) were identified from the chloroform fraction, including two first isolated compounds; dimethyl-malate (25) and 2-(2-hydroxyacetyl) furan (27) from this plants. Of these constituents, two compounds (gomisin T, and pregomisin) exhibited an NOX2-inhibitory effect with the IC₅₀ of 9.4 ± 3.6, and 62.9 ± 11.3 µM, respectively. They are confirmed not to be nonspecific superoxide scavengers in a counter assay using a xanthine-xanthine oxidase system. These findings suggest the potential application of gomisin T (6) and other constituents of S. chinensis to inhibit NOX2.
Chloroform ; Fruit ; Lignans ; Methanol ; NADP ; NADPH Oxidase ; Oxidoreductases ; Reactive Oxygen Species ; Schisandra ; Superoxides