Adenine Dinucleotide Phosphate Oxidase Activity Research Articles

Daphnetin inhibits RANKL-induced osteoclastogenesis in vitro.

Osteoporosis is a common orthopedic disease which is associated with hyper-activated osteoclastogenesis. Daphnetin is a natural coumarin derivative isolated from Genus Daphne, which possesses antiarthritis effect. However, the role of daphnetin in osteoclastogenesis has not been illustrated. This study aimed to investigate the effects of daphnetin on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis in vitro. Our results showed that the osteoclast formation was significantly suppressed by daphnetin treatment in bone marrow-derived macrophages (BMMs), which was illustrated by reduced number of tartrate-resistant acid phosphatase positive multinucleated osteoclasts and decreased expression levels of tumor necrosis factor receptor-associated factors (TRAF6), c-Fos, nuclear factor of activated T cells c1, and cathepsin K. RANKL caused significant induction effects in reactive oxygen species (ROS) generation and nicotinamide adenine dinucleotide phosphate oxidase activity, whereas the induction was dramatically reduced after pretreatment with daphnetin. In addition, daphnetin prevented the RANKL-induced activation of NF-κB and Akt/GSK-3β pathways in BMMs. These findings indicated that daphnetin exhibited an inhibitory effect on RANKL-induced osteoclastogenesis in vitro. The effect of daphnetin might be mediated by inhibiting ROS signal transduction, as well as preventing the activation of NF-κB and Akt/GSK-3β signaling pathways. These findings indicated that daphnetin might be considered as a new therapeutic approach for the osteoporosis treatment.

A Novel Synthetic Derivative of Phloroglucinol Inhibits Neuroinflammatory Responses Through Attenuating Kalirin Signaling Pathway in Murine BV2 Microglial Cells.

Neuroinflammation has been implicated as an important factor in the neurodegenerative diseases, and multiple candidates with anti-inflammatory effects have been shown to be beneficial for the treatment of neurodegenerative diseases. Our previous study demonstrated that a novel synthetic phloroglucinol derivative from Lysidice rhodostegia roots (code name: Compound 21) exerted neuroprotective effect through suppressing neuroinflammation. The aim of this study was to reveal the underlying molecular mechanism. The results indicated that the anti-inflammatory effects of Compound 21 were mediated through suppression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and the production of reactive oxygen species (ROS). Further study showed that this suppression on NADPH oxidase was mediated by inhibiting the translocation and activity of its subunit Rac1. It is well established that Rac1 activation is regulated by a variety of guanine nucleotide exchange factors (GEFs), so we tried to find out whether GEFs were involved in the anti-inflammatory effects of Compound 21. The results showed that Compound 21 treatment down-regulated the expression and activity of GEF Kalirin, thus modulating the activity of Rac1 GTPase. Altogether, our data suggested that Compound 21 exerted the anti-neuroinflammatory effect through suppressing Kalirin signaling pathways, decreasing Rac1-NADPH oxidase activation and the subsequent pro-inflammatory cytokine production. The present study provided solid evidence to support Compound 21 as a potential candidate of neuroinflammatory inhibitor. Moreover, our findings have shed new light on the role of Rac1 and GEF Kalirin in neuroinflammation, which provides potential targets for neuroinflammation-related diseases, such as neurodegenerative diseases.

Cellular response of oxidative stress when sub1A QTL of rice receives water deficit stress

In this experiment, sub1A quantitative trait loci (sub1A QTL) of rice were evaluated for dehydration responses through different aspects of cellular responses. Through variations of dehydration exposure, rice seedlings recorded a significant increase in superoxide (O2.-) and hydrogen peroxide (H2O2), the former by 1.80 fold and the latter by 2.10 fold. Nicotinamide adenine dinucleotide phosphate oxidase activity fairly correlated with lipid peroxidation (r = 1.96). Both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) had similar IC50 values over the control at p ? 0.05. Reducing power of the extract had 1.31 fold increase. The antioxidant moieties like total phenolics and flavonoids were 1.04 and 1.23 fold upregulated under stress. On the other hand anthocyanin and glutathione (GSH) did not vary much under stress except at maximum duration of stress. Superoxide dismutase (SOD) was initially stable but maximized at 8 days by 1.30 fold increase. On the contrary, guaiacol peroxidase (GPX) was seen to be downregulated by 40.94% all through the days of stress. Catalase (CAT) activity followed a similar trend, but was not significant as compared to control.

Association of advanced glycation end products in Dupuytren disease

BackgroundAdvanced glycation end products are associated with aging, hyperglycemia, and oxidative stress. Accumulation of advanced glycation end products can cause various pathological conditions; however, the association of Dupuytren’s disease with advanced glycation end products has not been demonstrated yet. The aim of this study is to investigate the association of Dupuytren’s disease with advanced glycation end products.MethodsNormal palmar fascia from five patients with carpal tunnel syndrome (control group) and Dupuytren’s cords from five patients (Dupuytren’s disease group) were harvested. The tissues were stained using an anti-advanced glycation end products antibody, anti-receptor for advanced glycation end products antibody, and an anti-reactive oxygen species modulator 1 antibody. The expression of nicotinamide adenine dinucleotide phosphate oxidase-1 and nicotinamide adenine dinucleotide phosphate oxidase-4 genes was also assessed using real-time PCR. For in vitro analysis, the cells harvested from the control and Dupuytren’s disease groups were used. After 3 days of exposure to four types of media (control group, control + advanced glycation end products group, Dupuytren’s disease group, Dupuytren’s disease + advanced glycation end products group), superoxide detection reagent was detected using a total reactive oxygen species/superoxide detection kit.ResultsImmunostaining of the palmar fasciae of the Dupuytren’s disease group showed higher expressions of advanced glycation end products and receptor for advanced glycation end products than that in the control group. The expression of nicotinamide adenine dinucleotide phosphate oxidase oxidase-1 and nicotinamide adenine dinucleotide phosphate oxidase-4 as well as reactive oxygen species modulator 1, an oxidatively damaged protein, was also higher in the Dupuytren’s disease group than in the control group. In an in vitro cell culture, the addition of advanced glycation end products to the Dupuytren’s disease-derived cells produced more superoxide free radicals.ConclusionsThese data suggest that the advanced glycation end products receptor for advanced glycation end products interaction produced free radicals via nicotinamide adenine dinucleotide phosphate oxidase activation in Dupuytren’s disease patients. Further studies are required to confirm these results.

Syringic acid prevents skin carcinogenesis via regulation of NoX and EGFR signaling

Validation of nutraceutical and pharmaceutical targets is essential for the prediction of physiological and side effects. Epidemiologic evidence and molecular studies suggest that non-melanoma skin cancer is directly associated with excessive exposure to ultraviolet (UV) radiation. The aim of the present study was to evaluate the inhibitory effects of syringic acid on UVB-induced signaling and skin carcinogenesis, and determine the molecular targets. Treatment of human epidermal keratinocytes (HaCaT) cells with syringic acid resulted in the suppression of UVB-induced cyclooxygenase-2, matrix metalloproteinase-1, and prostaglandin E2 expression as well as activator protein-1 activity. Moreover, syringic acid inhibited the UVB-induced phosphorylation of mitogen-activated protein kinases and Akt signaling pathways as well as epidermal growth factor receptor (EGFR). Syringic acid treatment further inhibited intracellular reactive oxygen species and protein-tyrosine phosphatase-κ activity, a regulator of EGFR activation. Syringic acid and the antioxidant N-acetyl-l-cysteine inhibited UVB-induced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. In vivo, pretreatment of mouse skin with syringic acid significantly suppressed UVB-induced skin tumor incidence in a dose-dependent manner. Overall, these results indicate that syringic acid exerts potent chemopreventive activity in skin carcinogenesis mainly by inhibition of the Nox/PTP-κ/EGFR axis. Syringic acid might serve as an effective chemopreventive and therapeutic agent against UVB-mediated skin cancer.

Oxidative Stress in Aortas of Patients with Advanced Occlusive and Aneurysmal Diseases

Aortoiliac occlusive disease (AOD) and abdominal aortic aneurysm (AAA) are very important cardiovascular diseases that present different aspects of pathophysiology; however, oxidative stress and inflammatory response seem be relevant in both of them. Our objective was to evaluate oxidative damage and degree of inflammatory infiltrate in aortas of patients surgically treated for AOD and AAA. Levels of reactive oxygen species (ROS), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, and myeloperoxidase (MPO) expression as well as nitrite levels and superoxide dismutase (SOD) and catalase (CAT) activities were evaluated in aortas of patients with AOD (n=16) or AAA (n=14), while the control group was formed by cadaveric organ donors (n=10). We also analyzed the degree of inflammatory infiltrate in these aortas. There was an increase in ROS levels and NADPH oxidase activity in patients with AOD and AAA when compared with the control group, and the AOD group demonstrated higher ROS production and NADPH oxidase activity and also nitrite levels when compared with the AAA group (P<0.001). On the other hand, an increase of SOD activity in the AOD group and CAT activity in the AAA group was observed. Inflammatory infiltrate and MPO expression were higher in the AOD group when compared with the control group (P<0.05). Oxidative stress is relevant in both AOD and AAA, though AOD presented higher ROS levels and NADPH activity. Increased activities of antioxidant enzymes may be a compensatory phenomenon which occurs in aortas of patients with AOD and AAA. Perhaps, a relationship between oxidative stress and degree of inflammatory infiltrate may exist in the pathophysiology of AOD and AAA.

Adiponectin/AdiopR1 signal inactivation contributes to impaired angiogenesis in mice of advanced age

BackgroundThe mechanism by which angiogenesis declines with aging remains largely unknown. Given that the plasma levels of adiponectin (APN) are decreased in the presence of ischemic cardiovascular disease, we explore the possible mechanisms by which APN/adiponectin receptor1 (AdipoR1) axis inactivation contributes to the decline in vascular regeneration capacity in elderly animals. Methods and resultsTo study aging-related changes in the APN/AdipoR1 axis and its impact on ischemia-induced angiogenesis, a hindlimb ischemia model was applied to young and aged mice. Aging impaired ischemia-induced blood flow recovery. An ELISA showed that the aged mice had decreased plasma APN levels. Immunostaining showed lesser capillary formation in the aged mice. The aged ischemic muscles had decreased levels of AdipoR1, peroxisome proliferator activated receptor-γ (PPAR-γ), PPAR-γ co-activator 1α (PGC-1α), phospho-AMP-activated protein kinase α (p-AMPK-α), and B cell lymphoma-2 (Bcl-2) and increased levels of cleaved caspase-8 (C-caspase-8) and gp91phox/p22phox genes or/and proteins, nicotinamide adenine dinucleotide phosphate oxidase activity, superoxide production, and matrix metalloproteinase-2/−9 activity as well as increased numbers of infiltrated macrophages and leucocytes. In in vitro experiments, aged endothelial cells had negative changes in the levels of PPAR-γ, PGC-1α, p-AMPK-α, Bcl-2, and C-caspase-8 proteins in response to oxidative stress. Genetic interventions targeted toward APN and AdipoR1 negatively affected the targeted angiogenic protein levels in aged muscles and angiogenic actions and/or aged endothelial events. ConclusionThese findings indicate that aging can reduce angiogenesis in response to hypoxia via an impaired APN-AdipoR1-dependent mechanism that may be mediated by PPAR-γ/PGC-1α signaling inactivation in advanced age.

The effect of carbon irradiation is associated with greater oxidative stress in mouse intestine and colon relative to γ-rays

Carbon irradiation due to its higher biological effectiveness relative to photon radiation is a concern for toxicity to proliferative normal gastrointestinal (GI) tissue after radiotherapy and long-duration space missions such as mission to Mars. Although radiation-induced oxidative stress is linked to chronic diseases such as cancer, effects of carbon irradiation on normal GI tissue have not been fully understood. This study assessed and compared chronic oxidative stress in mouse intestine and colon after different doses of carbon and γ radiation, which are qualitatively different. Mice (C57BL/6J) were exposed to 0.5 or 1.3 Gy of γ or carbon irradiation, and intestinal and colonic tissues were collected 2 months after irradiation. While part of the tissues was used for isolating epithelial cells, tissue samples were also fixed and paraffin embedded for 4 µm thick sections as well as frozen for biochemical assays. In isolated epithelial cells, reactive oxygen species and mitochondrial status were studied using fluorescent probes and flow cytometry. We assessed antioxidant enzymes and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in tissues and formalin-fixed tissue sections were stained for 4-hydroxynonenal, a lipid peroxidation marker. Data show that mitochondrial deregulation, increased NADPH oxidase activity, and decreased antioxidant activity were major contributors to carbon radiation-induced oxidative stress in mouse intestinal and colonic cells. When considered along with higher lipid peroxidation after carbon irradiation relative to γ-rays, our data have implications for functional changes in intestine and carcinogenesis in colon after carbon radiotherapy as well as space travel.

Optimization for extraction of an oil recipe consisting of white pepper, long pepper, cinnamon, saffron, and myrrh by supercritical carbon dioxide and the protective effects against oxygen–glucose deprivation in PC12 cells

This study is to investigate the most efficient extractives of extracting oil recipe for stroke treatment and the protective effects on an oxygen and glucose deprivation model in PC12 cells. An orthogonal experimental design L9 (34) was carried out for oil recipe's optimization with supercritical CO2 fluid extraction. 2-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and enzyme-linked immunosorbent assay were conducted to evaluate cell activity and indexes in the cell lysate. The result showed that the optimum extraction condition was 30Mpa, 50°C, 100min, the extracts were analyzed by gas chromatography–mass spectrometry and among forty detected compounds 27 were identified, representing 80.86% of the total oil content. trans-Cinnamaldehyde (14.14%), piperine (9.32%), β-amyrin (6.79%), lupenone (6.28%), longifolene (6.07%), β-caryophyllene (5.21%), α-bisabolol (4.11%), and β-bisabolene (2.56%) were high mass fraction. Oil recipe could significantly attenuate PC12 cell damage, the lactate dehydrogenase release and decreased the malondialdehyde levels, glutathione peroxidase and nicotinamide adenine dinucleotide phosphate oxidase activity, glutathione and nitric oxide content (p<0.01) and increased the level of superoxide dismutase after oxygen and glucose deprivation. The protective mechanism may be related to oil recipe's antioxidant effect by scavenging free radicals.

Regulation of Vascular Calcification by Growth Hormone-Releasing Hormone and Its Agonists.

Vascular calcification (VC) is a marker of the severity of atherosclerotic disease. Hormones play important roles in regulating calcification; estrogen and parathyroid hormones exert opposing effects, the former alleviating VC and the latter exacerbating it. To date no treatment strategies have been developed to regulate clinical VC. The objective of this study was to investigate the effect of growth hormone-releasing hormone (GHRH) and its agonist (GHRH-A) on the blocking of VC in a mouse model. Young adult osteoprotegerin-deficient mice were given daily subcutaneous injections of GHRH-A (MR409) for 4 weeks. Significant reductions in calcification of the aortas of MR409-treated mice were paralleled by markedly lower alkaline phosphatase activity and a dramatic reduction in the expression of transcription factors, including the osteogenic marker gene Runx2 and its downstream factors, osteonectin and osteocalcin. The mechanism of action of GHRH-A was dissected in smooth muscle cells isolated from human and mouse aortas. Calcification of smooth muscle cells induced by osteogenic medium was inhibited in the presence of GHRH or MR409, as evidenced by reduced alkaline phosphatase activity and Runx2 expression. Inhibition of calcification by MR409 was partially reversed by MIA602, a GHRH antagonist, or a GHRH receptor-selective small interfering RNA. Treatment with MR409 induced elevated cytosolic cAMP and its target, protein kinase A which in turn blocked nicotinamide adenine dinucleotide phosphate oxidase activity and reduced production of reactive oxygen species, thus blocking the phosphorylation of nuclear factor κB (p65), a key intermediate in the ligand of receptor activator for nuclear factor-κ B-Runx2/alkaline phosphatase osteogenesis program. A protein kinase A-selective small interfering RNA or the chemical inhibitor H89 abolished these beneficial effects of MR409. GHRH-A controls osteogenesis in smooth muscle cells by targeting cross talk between protein kinase A and nuclear factor κB (p65) and through the suppression of reactive oxygen species production that induces the Runx2 gene and alkaline phosphatase. Inflammation-mediated osteogenesis is thereby blocked. GHRH-A may represent a new pharmacological strategy to regulate VC.

Oxidative Stress and Renal Fibrosis: Recent Insights for the Development of Novel Therapeutic Strategies.

Chronic kidney disease (CKD) is a significant worldwide healthcare problem. Regardless of the initial injury, renal fibrosis is the common final pathway leading to end stage renal disease. Although the underlying mechanisms are not fully defined, evidence indicates that besides inflammation, oxidative stress plays a crucial role in the etiology of renal fibrosis. Oxidative stress results from an imbalance between the production of free radicals that are often increased by inflammation and mitochondrial dysfunction, and reduced anti-oxidant defenses. Several studies have demonstrated that oxidative stress may occur secondary to activation of transforming growth factor β1 (TGF-β1) activity, consistent with its role to increase nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) activity. A number of other oxidative stress-related signal pathways have also been identified, such as nuclear factor erythroid-2 related factor 2 (Nrf2), the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP)-cGMP-dependent protein kinase 1-phosphodiesterase (cGMP-cGK1-PDE) signaling pathway, and the peroxisome proliferator-activated receptor gamma (PPARγ) pathway. Several antioxidant and renoprotective agents, including cysteamine bitartrate, epoxyeicosatrienoic acids (EETs), and cytoglobin (Cygb) have demonstrated ameliorative effects on renal fibrosis in preclinical or clinical studies. The mechanism of action of many traditional Chinese medicines used to treat renal disorders is based on their antioxidant properties, which could form the basis for new therapeutic approaches. This review focuses on the signaling pathways triggered by oxidative stress that lead to renal fibrosis and provides an update on the development of novel anti-oxidant therapies for CKD.

Interaction between Mitochondrial Reactive Oxygen Species, Heme Oxygenase, and Nitric Oxide Synthase Stimulates Phagocytosis in Macrophages.

Macrophages are cells of the innate immune system that populate every organ. They are required not only for defense against invading pathogens and tissue repair but also for maintenance of tissue homeostasis and iron homeostasis. The aim of this study is to understand whether heme oxygenase (HO) and nitric oxide synthase (NOS) contribute to the regulation of nicotinamide adenine dinucleotide phosphate oxidase (NOX) activity and phagocytosis, two key components of macrophage function. This study was carried out using resting J774A.1 macrophages treated with hemin or vehicle. Activity of NOS, HO, or NOX was inhibited using specific inhibitors. Reactive oxygen species (ROS) formation was determined by Amplex® red assay, and phagocytosis was measured using fluorescein isothiocyanate-labeled bacteria. In addition, we analyzed the fate of the intracellular heme by using electron spin resonance. We show that both enzymes NOS and HO are essential for phagocytic activity of macrophages. NOS does not directly affect phagocytosis, but stimulates NOX activity via nitric oxide-triggered ROS production of mitochondria. Treatment of macrophages with hemin results in intracellular accumulation of ferrous heme and an inhibition of phagocytosis. In contrast to NOS, HO products, including carbon monoxide, neither clearly affect NOX activity nor clearly affect phagocytosis, but phagocytosis is accelerated by HO-mediated degradation of heme. Both enzymes contribute to the bactericidal activity of macrophages independently, by controlling different pathways.

Puerarin attenuates angiotensin II-induced cardiac fibroblast proliferation via the promotion of catalase activity and the inhibition of hydrogen peroxide-dependent Rac-1 activation

The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of H2O2 in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular H2O2. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of H2O2-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and H2O2-dependent Rac1 activation.

The mTOR promotes oxidative stress-induced apoptosis of mesangial cells in diabetic nephropathy.

Glomerular mesangial cell (MC) apoptosis is one of the important mechanisms of glomerulosclerosis, which induces an increased severity of albuminuria and promotes the development of diabetic nephropathy (DN). However, the mechanism by which high glucose (HG) induces MCs apoptosis is not fully understood. In the present study, we investigated the effects of mTOR signalling on apoptosis in cultured MCs exposed to HG and in type I diabetes, and tried to clarify the specific mechanisms underlying these effects. Invitro, exposure of MCs to HG stimulated ROS production, decreased the antioxidant enzyme superoxide dismutase (SOD) activity and glutathione (GSH) level, increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, upregulated P53 expression and Bax/Bcl-2 ratio and enhanced cleavage of caspase 3, resulting in an increase in programmed cell death. Pretreatment of the cells with rapamycin ameliorated oxidative stress, reduced the number of apoptotic cells induced by HG and caused the downstream effects of mTOR activation. Invivo, compared with control rats, diabetic rats had more apoptotic cells in glomeruli. Induction of diabetes increased the level of MDA and NADPH oxidase activity, decreased the SOD activity and GSH level, elevated the Bax/Bcl ratio and P53 expression and activated caspase 3. mTOR inhibitor rapamycin treatment prevented these changes further alleviated albuminuria and improved renal function. Taken together, our data suggest that mTOR plays a key role in mediating ROS-induced MC apoptosis in diabetic nephropathy, and these effects have been associated with the promotion of ROS production by upregulating the antioxidant enzyme and downregulating the NADPH oxidase activity.

Inhibition of NADPH Oxidase-Dependent Oxidative Stress in the Rostral Ventrolateral Medulla Mediates the Antihypertensive Effects of Acupuncture in Spontaneously Hypertensive Rats.

Oxidative stress in the rostral ventrolateral medulla (RVLM), where the sympathetic nervous control center is located, contributes to neural mechanisms of hypertension. Acupuncture was previously reported to favorably affect high blood pressure. However, little is known about the effect of acupuncture on oxidative stress-modulated mechanisms in hypertension. This study was designed to evaluate the hypothesis that acupuncture exerts an antihypertensive effect via ameliorating oxidative stress and the redox-sensitive pathway in the RVLM of spontaneously hypertensive rats. Two weeks of acupuncture reduced blood pressure and sympathetic nervous system activity in spontaneously hypertensive rats. Oxidative stress in the RVLM was alleviated by acupuncture, accompanied by a decrease in nicotinamide adenine dinucleotide phosphate oxidase activity and expression of its subunits. Acupuncture significantly altered the mitogen-activated protein kinases signaling pathway as assessed by pathway enrichment analysis in a gene chip assay. The phosphorylation of p38 mitogen-activated protein kinases and extracellular signal-regulated protein kinase 1/2, but not Jun N-terminal kinase, was downregulated by acupuncture. Microinjection bilaterally of the superoxide dismutase mimetic tempol, nicotinamide adenine dinucleotide phosphate oxidase inhibitor apocynin, or diphenyleneiodonium chloride into the RVLM mimicked the antihypertensive effect of acupuncture. In contrast, the nicotinamide adenine dinucleotide phosphate oxidase agonist tetrabromocinnamic acid abolished the beneficial effects of acupuncture. Furthermore, injection of capsaicin or surgical sectioning of the sciatic nerve abolished the antihypertensive effect of acupuncture. We conclude that acupuncture decreases high blood pressure and nicotinamide adenine dinucleotide phosphate oxidase in the RVLM of spontaneously hypertensive rats. The mitogen-activated protein kinases and the sciatic nerve are involved in the mechanism of acupuncture's amelioration of hypertension.

Neutrophil Phenotype Correlates With Postoperative Inflammatory Outcomes in Infants Undergoing Cardiopulmonary Bypass

Infants with congenital heart disease frequently require cardiopulmonary bypass, which causes systemic inflammation. The goal of this study was to determine if neutrophil phenotype and activation status predicts the development of inflammatory complications following cardiopulmonary bypass. Prospective cohort study. Tertiary care PICU with postoperative cardiac care. Thirty-seven patients 5 days to 10 months old with congenital heart disease requiring cardiopulmonary bypass. None. Laboratory and clinical data collected included length of mechanical ventilation, acute kidney injury, and fluid overload. Neutrophils were isolated from whole blood at three time points surrounding cardiopulmonary bypass. Functional analyses included measurement of cell surface protein expression and nicotinamide adenine dinucleotide phosphate oxidase activity. Of all patients studied, 40.5% displayed priming of nicotinamide adenine dinucleotide phosphate oxidase activity in response to N-formyl-Met-Leu-Phe stimulation 24 hours post cardiopulmonary bypass as compared to pre bypass. Neonates who received steroids prior to bypass demonstrated enhanced priming of nicotinamide adenine dinucleotide phosphate oxidase activity at 48 hours. Patients who displayed priming post cardiopulmonary bypass were 8.8 times more likely to develop severe acute kidney injury as compared to nonprimers. Up-regulation of neutrophil surface CD11b levels pre- to postbypass occurred in 51.4% of patients, but this measure of neutrophil priming was not associated with acute kidney injury. Subsequent analyses of the basal neutrophil phenotype revealed that those with higher basal CD11b expression were significantly less likely to develop acute kidney injury. Neutrophil priming occurs in a subset of infants undergoing cardiopulmonary bypass. Acute kidney injury was more frequent in those patients who displayed priming of nicotinamide adenine dinucleotide phosphate oxidase activity after cardiopulmonary bypass. This pilot study suggests that neutrophil phenotypic signature could be used to predict inflammatory organ dysfunction.

Role of endoplasmic reticulum stress in the protective effects of PPAR\u03b2/\u03b4 activation on endothelial dysfunction induced by plasma from patients\xa0with lupus

BackgroundWe tested whether GW0742, a peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) agonist, improves endothelial dysfunction induced by plasma from patients with systemic lupus erythematosus (SLE) involving the inhibition of endoplasmic reticulum (ER) stress.MethodsA total of 12 non-pregnant women with lupus and 5 non-pregnant healthy women (controls) participated in the study. Cytokines and double-stranded DNA autoantibodies (anti-dsDNA) were tested in plasma samples. Endothelial cells, isolated from human umbilical cord veins (HUVECs), were used to measure nitric oxide (NO), intracellular reactive oxygen species (ROS) production, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, and ER stress markers.ResultsInterferon-γ, interleukin-6, and interleukin-12 levels were significantly increased in plasma from patients with SLE with active nephritis (AN), as compared to both patients with SLE with inactive nephritis (IN) and the control group. The NO production stimulated by both the calcium ionophore A23187 and insulin was significantly reduced in HUVECs incubated with plasma from patients with AN-SLE as compared with the control group. Plasma from patients with IN-SLE did not modify A23187-stimulated NO production. Increased ROS production and NADPH oxidase activity were found in HUVECs incubated with plasma from patients with AN-SLE, which were suppressed by the ER stress inhibitor 4-PBA and the NADPH oxidase inhibitors, apocynin and VAS2870. GW0742 incubation restored the impaired NO production, the increased ROS levels, and the increased ER stress markers induced by plasma from patients with AN-SLE. These protective effects were abolished by the PPARβ/δ antagonist GSK0660 and by silencing PPARβ/δ.ConclusionsPPARβ/δ activation may be an important target to control endothelial dysfunction in patients with SLE.

Three variants in the nicotinamide adenine dinucleotide phosphate oxidase complex are associated with HCV-related liver damage.

Approximately 71 million people are chronically infected with the hepatitis C virus (HCV), a potentially lethal pathogen. HCV generates oxidative stress correlating with disease severity. HCV proteins increase reactive oxygen species production by stimulating nicotinamide adenine dinucleotide phosphate oxidase (NOX) activity. Reactive oxygen species are necessary for host defense and cell signaling; however, elevated NOX activity contributes to cancer, and NOX overexpression is associated with hepatic fibrosis. Our aim was to investigate whether single nucleotide polymorphisms (SNPs) in NOX family members are associated with HCV‐related liver damage. Three hundred and thirty‐one individuals of European ancestry and 90 individuals of African ancestry, all diagnosed with HCV, were genotyped for 243 tagSNPs in NOX enzymes and their regulatory factors. Pathology scores were available for 288 Caucasians and 71 Africans, and mortality status was determined for all subjects. SNPs were tested for association with pathology scores and as predictors of mortality. In Africans, homozygosity for the A allele of rs12753665 (neutrophil cytosolic factor 2) and homozygosity for the T allele of rs760519 (neutrophil cytosolic factor 4) were associated with and predictive of higher rates of advanced fibrosis and cirrhosis compared to other genotypes after controlling for age and sex. In Caucasians, homozygosity for the T allele of rs2292464 (dual oxidase 1) was associated with and predictive of decreased periportal inflammation after controlling for age and sex. No SNPs were significant predictors of mortality. Conclusion: In this exploratory study, three NOX‐related polymorphisms in two ethnic groups were significantly associated with hepatic inflammation and fibrosis. Future studies investigating these SNPs in larger cohorts of patients with HCV are warranted. (Hepatology Communications 2017;1:973–982)

Cilostazol Suppresses Aβ-induced Neurotoxicity in SH-SY5Y Cells through Inhibition of Oxidative Stress and MAPK Signaling Pathway.

Alzheimer’s disease (AD) is a slowly progressive form of dementia, characterized by memory impairment and cognitive dysfunction. AD is mainly characterized by the deposition of amyloid β (Aβ) plaques and intracellular neurofibrillary tangles in the brain, along with neuronal degeneration and high levels of oxidative stress. Cilostazol (CSZ) was recently found to suppress the progression of cognitive decline in patients with stable AD receiving acetylcholinesterase inhibitors. This present study aimed to clarify the mechanism by which CSZ protects neurons from degeneration associated with Aβ(1–42). We used Aβ(1–42) to induce neurotoxicity in human neuroblastoma SH-SY5Y cells. Cells were pretreated with CSZ before co-treatment with Aβ. To evaluate the effect of CSZ on oxidative stress, we examined levels of reactive oxygen species (ROS), nicotinamide adenine dinucleotide phosphate oxidase (Nox) activity, mRNA expression of NOX4, and Cu/Zn-Superoxide Dismutase (SOD), as well as apoptosis biomarkers [MTT, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), caspase-3 and -9 activities and staining of annexin V]. We also assayed the activity of mitogen-activated protein kinases (MAPK): p38 MAPK and extracellular signal-regulated kinase1/2 (ERK1/2), and biomarkers of mitochondrial function (Bcl-2 and Bax), and cyclic adenosine monophosphate response element-binding protein (CREB). Aβ-induced oxidative stress (ROS, NOX4 activity, and expression of NOX mRNA), caspase activation (caspase-3 and -9), and p38 MAPK phosphorylation were suppressed by co-treatment with CSZ, but not by ERK1/2 activation. In addition, pretreatment with CSZ suppressed Aβ-induced apoptosis and increased cell viability via suppression of Bax (a proapoptotic protein), upregulation of Bcl-2 (an antiapoptotic protein) and Cu/Zn-SOD (a superoxide scavenging enzyme), and phosphorylation of CREB. These findings suggested that CSZ could counteract neurotoxicity through multiple mechanisms, one mechanism involving the attenuation of oxidative stress by suppressing NOX activity and Nox mRNA expression in Aβ-induced neurotoxicity and another involving the anti-neurotoxic effect via the ERK1/2/phosphorylated CREB pathway.

Long Term Osmotic Mini Pump Treatment with Alpha-MSH Improves Myocardial Function in Zucker Diabetic Fatty Rats.

The present investigation evaluates the cardiovascular effects of the anorexigenic mediator alpha-melanocyte stimulating hormone (MSH), in a rat model of type 2 diabetes. Osmotic mini pumps delivering MSH or vehicle, for 6 weeks, were surgically implanted in Zucker Diabetic Fatty (ZDF) rats. Serum parameters, blood pressure, and weight gain were monitored along with oral glucose tolerance (OGTT). Echocardiography was conducted and, following sacrifice, the effects of treatment on ischemia/reperfusion cardiac injury were assessed using the isolated working heart method. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity was measured to evaluate levels of oxidative stress, and force measurements were performed on isolated cardiomyocytes to determine calcium sensitivity, active tension and myofilament co-operation. Vascular status was also evaluated on isolated arterioles using a contractile force measurement setup. The echocardiographic parameters ejection fraction (EF), fractional shortening (FS), isovolumetric relaxation time (IVRT), mitral annular plane systolic excursion (MAPSE), and Tei-index were significantly better in the MSH-treated group compared to ZDF controls. Isolated working heart aortic and coronary flow was increased in treated rats, and higher Hill coefficient indicated better myofilament co-operation in the MSH-treated group. We conclude that MSH improves global heart functions in ZDF rats, but these effects are not related to the vascular status.