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

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 investigate the effect of angiotension II (AngII) on the activation of NLRP3 inflammasome and the expression of interleukin-1β (IL-1β) in human umbilical vein endothelial cells (HUVECs).

METHODSHUVECs cultured in vitro were treated with different concentrations of AngII for varying lengths of time to determine the optimal concentration and time for AngII exposure. To test the impact of different agents on the effect of AngII exposure, HUVECs were pretreated with AngII receptor blocker losartan, NAD(P)H inhibitor DPI and H(2)O(2) scavenger CAT, caspase 1 inhibitor YVAD, or NLRP3 siRNA for silencing NLRP3, and the protein levels of NOX4, NLRP3, caspase-1 and IL-1β in HUVECs were analyzed by Western blotting.

RESULTSAngII treatment at the optimal concentration (10(-9) mol/L) for 12 h significantly increased the protein levels of NOX4, NLRP3, caspase1 and IL-1β in HUVECs. Pretreatment with losartan, DPI, CAT, YVAD, or NLRP3 siRNA all attenuated the effects of AngII on the cells.

CONCLUSIONAngII can induce vascular inflammation by promoting the production of reactive oxygen species and activating NLRP3 inflammasome to increase the protein expression of IL-1β in HUVECs.

Adaptor Proteins, Signal Transducing ; pharmacology ; Angiotensin II ; pharmacology ; Blotting, Western ; Carrier Proteins ; metabolism ; Caspase 1 ; metabolism ; Human Umbilical Vein Endothelial Cells ; metabolism ; Humans ; Hydrogen Peroxide ; Inflammasomes ; metabolism ; Interleukin-1beta ; metabolism ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; RNA, Small Interfering ; Reactive Oxygen Species ; metabolism

OBJECTIVEBoth of gp91(phox) (an isoform of nicotinamide adenine dinucleotide phosphate-reduced oxidases) and Src (a non-receptor protein tyrosine kinase) play a prominent role in mediating hypoxia/reoxygenation injury of neurons. The present study was designed to investigate the neuroprotective effect of equol, a predominant active metabolite of daidzein, against hypoxia/reoxygenation injury in rat pheochromocytoma cell line (PC12) and explore the underlying mechanisms.

METHODSPC12 cells exposed to hypoxia/reoxygenation injury were examined for reactive oxygen species (ROS) using dihydroethidium and 2', 7'-dichlorofluorescein diacetate and analyzed for changes in lactate dehydrogenase (LDH) activity and malondialdehyde (MDA) content. The expression levels of gp91(phox) and phosphorylated Src-Tyr416 (p-Src) were measured using Western blotting.

RESULTSEquol dose-dependently restored the cell viability and decreased LDH activity and MDA content in culture medium of PC12 cells exposed to hypoxia/reoxygenation. Pretreatment of the cells with 10(-5) and 10(-6) mol/L equol inhibited hypoxia/reoxygenation-induced increase of ROS. PC12 cells treated with equol prior to hypoxia/reoxygenation injury showed significant enhancement of the protein levels of gp91(phox) and p-Src.

CONCLUSIONEquol confers neuroprotection against hypoxia/reoxygenation injury in PC12 cells by inhibiting the generation of ROS very likely as a result of down-regulation of gp91(phox) and inhibition of Src phosphorylation.

Animals ; Cell Hypoxia ; Cell Survival ; Down-Regulation ; Equol ; pharmacology ; L-Lactate Dehydrogenase ; metabolism ; Malondialdehyde ; metabolism ; Membrane Glycoproteins ; metabolism ; NADPH Oxidase 2 ; NADPH Oxidases ; metabolism ; Neurons ; drug effects ; metabolism ; Neuroprotective Agents ; pharmacology ; PC12 Cells ; Phosphorylation ; Rats ; Reactive Oxygen Species ; metabolism ; src-Family Kinases ; metabolism

OBJECTIVETo evaluate the effect of palmitic acid (PA) on oxidative stress and activation of inflammasomes in hepatocytes.

METHODSTo test the dose-dependent effect of PA on normal murine hepatocytes AML12, the cells were treated with 0, 0.15, 0.25 and 0.4 mmol/L of palmitic acid (PA). The cells were also divided into blank control group, 0.25 mmol/L PA group and 0.25 mmol/L PA+N-acetylcysteine (NAC) group to examine the effect of reactive oxygen species (ROS) on the activation of inflammasomes. After 24 h of treatment, lipid accumulation, total ROS, mitochondrial ROS, expression and localization of NOX4, and expressions of inflammasomes and IL-1β were detected in the hepatocytes.

RESULTSCompared with the control cells, PA treatment of the cells significantly increased cytoplasmic lipid accumulation, concentrations of total ROS (12 463.09±2.72 vs 6691.23±2.45, P=0.00) and mitochondrial ROS (64.98±0.94 vs 45.04±0.92, P=0.00), and the expressions of NOX4, NLRP3, ASC, caspase-1, and IL-1β (1603.52±1.32 vs 2629.33±2.57, P=0.00). The mitochondria and NOX4 were found to be co-localized in the cytoplasm. NAC obviously reduced cellular ROS level stimulated by PA (7782.15±2.87 vs 5445.6±1.17, P=0.00) and suppressed the expressions of NLRP3, ASC and caspase-1.

CONCLUSIONPA treatment can stimulate lipid accumulation in hepatocytes and induce oxidative stress through NOX4 and mitochondria pathway to activate inflammasomes and stimulate the secretion of IL-1β.

Acetylcysteine ; pharmacology ; Animals ; Carrier Proteins ; metabolism ; Caspase 1 ; metabolism ; Cells, Cultured ; Hepatocytes ; drug effects ; metabolism ; Inflammasomes ; drug effects ; metabolism ; Interleukin-1beta ; metabolism ; Mice ; Mitochondria ; drug effects ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; Oxidative Stress ; Palmitic Acid ; pharmacology ; Reactive Oxygen Species ; metabolism

OBJECTIVETo investigate the role of NADPH oxidase (Nox) in the oxidative stress injury of human dermal fibroblasts (HFbs).

METHODSAn oxidative stress injury model was established in HFbs by exposure to H(2)O(2). Normal HFbs and HFbs exposed to H(2)O(2) with and without pretreatment with NADPH oxidase inhibitor were tested for cell viability using MTT assay, and the intracellular reactive oxygen species (ROS) were determined with a DCFH-DA fluorescent probe. Western blotting was used to measure the protein expressions of membrane-bound subunit gp91phox of NADPH oxidase in the cells.

RESULTH(2)O(2) time- and concentration-dependently induced oxidative stress injury in the fibroblasts, causing a reduction of the cell viability to 40% after a 24-h exposure at 700 µmol/L (P<0.05) and an increase of ROS by 2 folds after a 2-h exposure at 700 µmol/L (P<0.05). Compared with the cells with oxidative stress injury, the cells with NADPH oxidase inhibitor pretreatment showed a 20% higher cell viability (P<0.05) and normal ROS level (P<0.05) following H(2)O(2) exposure. Western blotting demonstrated increased expression of gp91phox in the cells exposed to increasing H(2)O(2) concentrations, but gp91phox expression remained normal in cells pretreated with NADPH oxidase inhibitor.

CONCLUSIONH(2)O(2) can induce oxidative stress injury in the fibroblasts by affecting NADPH oxidase, especially its membrane-bound subunit gp91phox.

Cell Survival ; Cells, Cultured ; Fibroblasts ; cytology ; enzymology ; Humans ; Hydrogen Peroxide ; Membrane Glycoproteins ; metabolism ; NADPH Oxidase 2 ; NADPH Oxidases ; antagonists & inhibitors ; metabolism ; Oxidation-Reduction ; Oxidative Stress ; Reactive Oxygen Species ; metabolism

OBJECTIVETo investigate the molecular mechanism by which salidroside protects PC12 cells from HO-induced apoptosis.

METHODSPC12 cells cultured in DMEM supplemented with 10% horse serum and 5% fetal bovine serum were pretreated with different doses of salidroside for 2 h and then stimulated with HOfor different lengths of time. The expression levels of PARP and caspase 3 and the phosphorylation of p38, ERK and JNK were determined with Western blotting. The cell nuclear morphology was observed after DAPI staining. The production of ROS was detected using a ROS detection kit, and the levels of gp91and p47in the membrane and cytoplasm were detected by membrane-cytoplasm separation experiment; the binding between gp91and p47was assayed by coimmunoprecipitation experiment.

RESULTSSalidroside dose-dependently suppressed cell apoptosis, lowered phosphorylation levels of p38, ERK and JNK, inhibited the production of ROS, reduced the binding between gp91and p47, and inhibited the activity of NOX2 in PC12 cells exposed to HO.

CONCLUSIONSalidroside protects PC12 cells from HO-induced apoptosis at least partly by suppressing NOX2-ROS-MAPKs signaling pathway.

Animals ; Apoptosis ; Caspase 3 ; metabolism ; Glucosides ; pharmacology ; Hydrogen Peroxide ; MAP Kinase Signaling System ; drug effects ; Membrane Glycoproteins ; metabolism ; NADPH Oxidase 2 ; NADPH Oxidases ; metabolism ; Neuroprotective Agents ; pharmacology ; PC12 Cells ; Phenols ; pharmacology ; Phosphorylation ; Rats ; Reactive Oxygen Species ; metabolism

Elevated plasma concentration of native low-density lipoprotein (nLDL) is associated with vascular smooth muscle cell (VSMC) activation and cardiovascular disease. We investigated the mechanisms of superoxide generation and its contribution to pathophysiological cell proliferation in response to nLDL stimulation. Lucigenin-induced chemiluminescence was used to measure nLDL-induced superoxide production in human aortic smooth muscle cells (hAoSMCs). Superoxide production was increased by nicotinamide adenine dinucleotide phosphate (NADPH) and decreased by NADPH oxidase inhibitors in nLDL-stimulated hAoSMC and hAoSMC homogenates, as well as in prepared membrane fractions. Extracellular signal-regulated kinase 1/2 (Erk1/2), protein kinase C-theta (PKCtheta) and protein kinase C-beta (PKCbeta) were phosphorylated and maximally activated within 3 min of nLDL stimulation. Phosphorylated Erk1/2 mitogen-activated protein kinase, PKCtheta and PKCbeta stimulated interactions between p47phox and p22phox; these interactions were prevented by MEK and PKC inhibitors (PD98059 and calphostin C, respectively). These inhibitors decreased nLDL-dependent superoxide production and blocked translocation of p47phox to the membrane, as shown by epifluorescence imaging and cellular fractionation experiments. Proliferation assays showed that a small interfering RNA against p47phox, as well as superoxide scavenger and NADPH oxidase inhibitors, blocked nLDL-induced hAoSMC proliferation. The nLDL stimulation in deendothelialized aortic rings from C57BL/6J mice increased dihydroethidine fluorescence and induced p47phox translocation that was blocked by PD98059 or calphostin C. Isolated aortic SMCs from p47phox-/- mice (mAoSMCs) did not respond to nLDL stimulation. Furthermore, NADPH oxidase 1 (Nox1) was responsible for superoxide generation and cell proliferation in nLDL-stimulated hAoSMCs. These data demonstrated that NADPH oxidase activation contributed to cell proliferation in nLDL-stimulated hAoSMCs.
Animals ; Aorta/*cytology ; Cell Line ; Cell Proliferation ; Cells, Cultured ; Humans ; Lipoproteins, LDL/*metabolism ; Mice, Inbred C57BL ; Mitogen-Activated Protein Kinases/metabolism ; Muscle, Smooth, Vascular/cytology ; Myocytes, Smooth Muscle/*cytology ; NADPH Oxidase/*metabolism ; Phosphorylation ; Protein Kinase C/metabolism ; Signal Transduction ; Superoxides/metabolism

The aim of the present study is to investigate the protective effect of chrysin (5,7-dihydroxyflavone) on right ventricular remodeling in a rat model of monocrotaline-induced pulmonary arterial hypertension (PAH). PAH rats were induced by a single injection of monocrotaline (60 mg x kg(-1), sc) and were administered with chrysin (50 or 100 mg x kg(-1) x d(-1)) for 4 weeks. At the end of experiment, the right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) were monitored via the right jugular vein catheterization into the right ventricle. Right ventricle (RV) to left ventricle (LV) + septum (S) and RV to tibial length were calculated. Right ventricular morphological change was observed by HE staining. Masson's trichrome stain was used to demonstrate collagen deposition. The total antioxidative capacity (T-AOC) and malondialdehyde (MDA) levels in right ventricle were determined according to the manufacturer's instructions. The expressions of collagen I, collagen III, NADPH oxidase 4 (NOX4) and nuclear factor-kappa B (NF-κB) were analyzed by immunohistochemisty, qPCR and (or) Western blot. The results showed that chrysin treatment for 4 weeks attenuated RVSP, mPAP and right ventricular remodeling index (RV/LV+S and RV/Tibial length) of PAH rats induced by monocrotaline. Furthermore, monocrotaline-induced right ventricular collagen accumulation and collagen I and collagen III expression were both significantly suppressed by chrysin. The expressions of NOX4, NF-κB and MDA contents were obviously decreased, while the T-AOC was significantly increased in right ventricule from PAH rats with chrysin treatment. These results suggest that chrysin ameliorates right ventricular remodeling of PAH induced by monocrotaline in rats through its down-regulating of NOX4 expression and antioxidant activity, and inhibiting NF-κB expression and collagen accumulation.
Animals ; Blotting, Western ; Collagen ; metabolism ; Disease Models, Animal ; Flavonoids ; pharmacology ; Heart Ventricles ; drug effects ; metabolism ; Hypertension, Pulmonary ; chemically induced ; metabolism ; Monocrotaline ; toxicity ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; NF-kappa B ; metabolism ; Rats ; Ventricular Remodeling ; drug effects