Search

Cold atmospheric plasmas (CAPs) have been shown to be capable of enhancing stem cell differentiation, especially directed differentiation of neural stem cells (NSCs). Consequently, one-step CAP treatment shows promise as an aid to tissue transplantation. However, the mechanisms involved in the enhancement of NSCs differentiation by CAP treatment are not yet fully understood. We have previously shown that in atmospheric helium plasma jet treatment, nitric oxide (NO) is the main factor involved in promoting NSC differentiation. This article further investigated the possible signaling pathways stimulated by NO in the neuronal differentiation of C17.2-NSCs after plasma treatment. Extracellular and intracellular NO concentrations were measured at different time points of incubation to monitor NO production. Meanwhile, the expressions of related genes and proteins were detected by quantitative real-time polymerase chain reaction and western blot, respectively. It is found that plasma treatment could both generate extracellular NO and increase extracellular NO concentration by inducing inducible nitric oxide synthase expression. The synergetic effect of extracellular and intracellular NO then downregulated Notch1 and Id2, and upregulated Ngn2 and Ascl1, thereby activating downstream NeuroD expression and finally enhancing and directing differentiation of NSCs into neurons. [ABSTRACT FROM AUTHOR]

Background: Suppression of nitric oxide synthesis and stimulation of smooth muscle proliferation by increased serum levels of uric acid has a pathogenetic contribution towards accelerated atherogenesis of blood vessels of subjects with hyperuricemia. The objective of this work was to find out the prevalence of hyperuricemia in subjects who presented with unstable angina/myocardial infarction and their prognosis. Methods: This cross-sectional study was carried out in the Cardiology unit of Ayub Teaching Hospital, Abbottabad from 1st September, 2018 to 28th February, 2019. One hundred and ninety-nine subjects who were diagnosed with acute coronary syndrome (ACS) were enrolled in this study using non-probability consecutive sampling. ACS was diagnosed on the basis of history, electrocardiogram (ECG) findings and on the presence of elevated cardiac biomarkers. Uric acid levels were checked in less than 24 hours of presentation and subjects were grouped into hyperuricemic and normouricemic groups according to their serum levels of uric acid. After those patients in both groups were observed by comparing the presence or absence of complications between the two groups. The data was collected on a structured proforma and was statistically assessed with the help of version 16 of SPSS software. Results: Among 199 study participants, there were 146 (73.37%) male and 53 (26.63%) female patients. The mean age of patients in this study was 57.99±6.07 years with a range of 48--68 years. Hyperuricemia was diagnosed in 50 (25.13%) study participants. Among complications, 15 patients (7.94%) had cardiogenic shock, 27 (13.57%) had heart failure, 10 (5.03%) had cardiac arrhythmias, 16 (8.04%) had conduction defects and hyperuricemia was diagnosed in 50 (25.13%) patients. Cardiogenic shock was more common in patients with hyperuricemia (p<0.05). Conclusion: Hyperuricemia can result in multiple complications in patients who have an acute coronary event. Regular screening / monitoring of serum uric acid level in general population can prevent the direct as well as indirect morbidity associated with hyperuricemia. [ABSTRACT FROM AUTHOR]

Nitrate-reducing oral bacteria have gained a lot of interest due to their involvement in nitric oxide (NO) synthesis and its important cardiometabolic outcomes. Consortia of nitrate-metabolizing oral bacteria associated with cardiometabolic health and cognitive function have been recently identified. Longitudinal studies and clinical trials have shown that chronic mouthwash use is associated with increased blood pressure and increased risk for prediabetes/diabetes and hypertension. Concurrently, recent studies are beginning to shed some light on the complexity of nitrate reduction pathways of oral bacteria, such as dissimilatory nitrate reduction to ammonium (DNRA), which converts nitrite into ammonium, and denitrification, which converts nitrite to NO, nitrous oxide, and dinitrogen. These pathways can affect the composition and metabolism of the oral microbiome; consequently, salivary nitrate and nitrite metabolism have been proposed as targets for probiotics and oral health. These pathways could also affect systemic NO levels because NO generated through denitrification can be oxidized back to nitrite in the saliva, thus facilitating flux along the NO3–-NO2–-NO pathway, while DNRA converts nitrite to ammonium, leading to reduced NO. It is, therefore, important to understand which pathway predominates under different oral environmental conditions, since the clinical consequences could be different for oral and systemic health. Recent studies show that oral hygiene measures such as tongue cleaning and dietary nitrate are likely to favor denitrifying bacteria such as Neisseria, which are linked with better cardiometabolic health. A vast body of literature demonstrates that redox potential, carbon-to-nitrate ratio, and nitrate-to-nitrite ratio are key environmental drivers of the competing denitrification and DNRA pathways in various natural and artificial ecosystems. Based on this information, a novel behavioral and microbial model for nitric oxide metabolism and health is proposed, which links lifestyle factors with oral and systemic health through NO metabolism. [ABSTRACT FROM AUTHOR]

Even though natural sources of air pollution account for over 50% of sulphur compounds, 93% of nitrogen oxide which are the most dangerous artificial anthropogenic sources of air pollution and primarily associated with the combustion of fossil fuel. Coal-fired thermal power plants and industrial fuel-burning plants that emit large quantities of nitrogen oxides (NO and NO2), solids (ash, dust, soot), as well as carbon oxides, aldehydes, organic acids into the atmosphere pollute the environment in majority. In the present work, a mathematical model and a scheme for calculating the formation of nitrogen oxide has been developed. Also, the dependence of the rate of release of fuel nitrogen from coal particles at the initial stage of gasification and content of volatiles has been obtained. The main regularities of the formation of NOx at the initial section of the flame in the ignition zone of the swirl burner flame during the combustion of Ekibastuz coal have been revealed. Modern environmental requirements for the modernization of existing and the creation of new heat and power facilities determine the exceptional relevance of the development of effective methods and constructions to reduce emissions of nitrogen oxides, sulfur oxides and ash to 200, 300, and 100 mg/nm³ at α = 1.4. The dust consumption in all experiments was kept constant and amounted to 0.042 g/s, as well as with the results of calculating the thermal decomposition of the Ekibastuz coal dust, the recombination of atomic nitrogen into nitrogen molecules, and the kinetics of the formation of fuel nitric oxide. It was found that despite the presence of oxygen in Ekibastuz coal for gases Odaf = 11.8 % in an inert atmosphere, nitrogen oxides are not formed. [ABSTRACT FROM AUTHOR]

The aim of work is construction of correlation fields with trend lines and determination of the directionality of relationships between the investigated indicators of endothelial dysfunction, hypoxia and oxidative stress. Our results indicate that Willebrand factor, endothelin-1, 2,3-diphosphoglycerate, MDA, diene conjugates and eNOS are informative markers in the pathogenesis of experimental diabetic retinopathy. As a result of the research, it was established that there is a direct linear relationship between the Willebrand factor indicator and malondialdehyde, since the points of the correlation field are practically located on a straight line. We trace a similar type of direct linear relationship between Willebrand factor and diene conjugates. The specified results confirm the mutually aggravating relationship between the development of endothelial dysfunction and oxidative stress. We trace an inverse linear relationship between Willebrand factor and peroxidase. With an increase in Willebrand factor indicators by stages, we trace a decrease in peroxidase indicators, which indicates a relationship between endothelial dysfunction and a weakening of antioxidant protection. As a result of the study, it was established that the first two indicators: malondialdehyde and diene conjugates have an almost direct linear relationship with endothelin-1 indicators. These results confirm the relationship between the functional and structural state of the endothelium and the development of oxidative stress. It was established that the peroxidase indicator has an inverse linear relationship with the endothelin-1 indicators, which, as in the case of the Willebrand factor, indicates a violation of antioxidant protection in the event of endothelial dysfunction. As a result of the analysis of the dependence of the indicators of 2,3 diphosphoglycerate, Willebrand factor and eNOS, it was found that in the first two pairs of indicators, there is an inverse linear relationship between the indicators. As eNOS levels increase by stage, levels of 2,3 diphosphoglycerate and Willebrand factor decrease. In the case of an inverse relationship between the parameters of the Willebrand factor and eNOS, a practically functional connection is observed, since the coefficient of determination is almost 1. The obtained results indicate that the violation of the structural and functional state of the endothelium and the development of hypoxia are interconnected with the violation of the physiological pathway of oxide synthesis nitrogen. The relationship between the indicators of 2,3 diphosphoglycerate and the Willebrand factor was revealed, which has a direct relationship between the variables, which once again confirms the aggravating interaction between hypoxia and endothelial dysfunction.

• Spermidine (Spd) play a positive role in plant responses to saline-alkaline stress. • Exogenous Spd stimulates NO synthesis under saline-alkaline stress. • Exogenous Spd enhances the tolerance of tomato plants to saline-alkaline stress depend on NO. Spermidine (Spd) and nitric oxide (NO) are closely intertwined in their synthesis and play a significant role in plant responses to saline-alkaline stress. However, the specific interactions between Spd and NO in alleviating the toxicity of saline-alkaline stress in plants remain poorly understood. In this study, we aimed to elucidate the involvement of NO in the regulation of saline-alkaline stress tolerance by spermidine (Spd). To achieve this, we employed exogenous Spd treatment, NO synthesis inhibitors, and NO scavengers. We found that exogenous Spd stimulates NO synthesis in the leaves and roots of tomato seedlings by upregulating the nitrate reductase (NR) activities and the expression of its coding gene SlNR1. Importantly, when NO synthesis is inhibited or NO is scavenged, the regulatory effects of Spd on proline content, antioxidant enzyme system, ionic homeostasis, and the expression of genes involved in Na+/ K +homeostasis in tomato seedlings are compromised under saline-alkaline stress. These observations suggest that NO plays a pivotal role in the defensive mechanisms induced by Spd against saline-alkaline stress in tomato seedlings. Consequently, Spd enhances the tolerance of tomato plants to saline-alkaline stress by regulating the nitrate reductase (NR) signaling pathway and mediating NO synthesis. [ABSTRACT FROM AUTHOR]

We present a combined experimental and theoretical study of NO(v = 3 → 3, 2, 1) scattering from a Au(111) surface at incidence translational energies ranging from 0.1 to 1.2 eV. Experimentally, molecular beam–surface scattering is combined with vibrational overtone pumping and quantumstate selective detection of the recoiling molecules. Theoretically, we employ a recently developed first-principles approach, which employs an Independent Electron Surface Hopping (IESH) algorithm to model the nonadiabatic dynamics on a Newns-Anderson Hamiltonian derived from density functional theory. This approach has been successful when compared to previously reported NO/Au scattering data. The experiments presented here show that vibrational relaxation probabilities increase with incidence energy of translation. The theoretical simulations incorrectly predict high relaxation probabilities at low incidence translational energy. We show that this behavior originates from trajectories exhibiting multiple bounces at the surface, associated with deeper penetration and favored (N-down) molecular orientation, resulting in a higher average number of electronic hops and thus stronger vibrational relaxation. The experimentally observed narrow angular distributions suggest that mainly single-bounce collisions are important. Restricting the simulations by selecting only single-bounce trajectories improves agreement with experiment. The multiple bounce artifacts discovered in this work are also present in simulations employing electronic friction and even for electronically adiabatic simulations, meaning they are not a direct result of the IESH algorithm. This work demonstrates how even subtle errors in the adiabatic interaction potential, especially those that influence the interaction time of the molecule with the surface, can lead to an incorrect description of electronically nonadiabatic vibrational energy transfer in molecule-surface collisions. [ABSTRACT FROM AUTHOR]

Aim: In this study, we aimed to investigate the role of methylarginines in renal failure and the process leading to failure. Acute Renal Failure (ARF) is defined as sudden onset, damage and loss of renal function. Chronic Kidney Disease (CKD) is generally defined as the presence of decreased renal function loss that persists for more than 3 months. Methylarginines are arginine derivatives which inhibit ischemia and vasoconstriction by inhibiting nitric oxide synthesis, causing ischemia and damage. Methylarginines are metabolized mainly in the kidney. Their metabolism is in the form of direct excretion and enzymatic degradation. Material and Methods: The study was conducted from 2017 through 2018 in 89 patient (serum creatinine levels above 1.5 mg/ dL) and 54 healthy control cases. Methylarginines were analyzed in positive mode from Turbo Ion Spray Electrospray (ESI) using ABSCIEX API 3200 High Performance Liquid Chromatography mass spectrometry (LC-MS / MS) instrument using C18 column. Urea and creatinine were analyzed by Beckman Coulter AU5800 Series. Results were evaluated with SPSS system. Results: A significant difference was found in terms methylarginines urea and creatinine when patient and control groups compared. However, only creatinine and creatinine clearance values differences were found in patient groups in terms of acute and chronic renal failure (respectively, p = 0.001 for creatinine and p = 0.028 for creatinine clearance).There was no difference in terms of other parameters. Conclusions: Methylarginines can be considered as new and high potential biomarkers for evaluating renal function. However, it is not considered to be adequate for show the prognosis of the disease. [ABSTRACT FROM AUTHOR]

Bullfrog oil (BFO) is a natural product from the adipose tissue of the amphibian Rana catesbeiana Shaw, a bio-product rich in polyunsaturated fatty acids, which claims anti-inflammatory activity. The objective of this work was to evaluate the cytotoxicity and the anti-inflammatory activity of BFO using in vivo and in vitro assays. Thus, the in vitro cytotoxicity was assessed by the MTT assay. Additionally, the in vivo anti-inflammatory activity was performed by the carrageenan-induced paw edema model in Wistar rats, followed by histological analysis. Moreover, the BFO effect on inflammatory pathways was investigated by in vitro evaluation of the nitric oxide (NO) synthesis, and type-6 interleukin (IL-6) and tumor-necrosisfactor (TNF) levels. In vivo experiments showed that BFO administered by intragastric route produced a significant anti-inflammatory effect, which was as substantial as indomethacin, the positive control. Histopathological analysis confirmed these results, showing the absence of the edema and minimal signs of inflammation in the paws of rats treated with BFO. The MTT results showed that BFO at all tested concentrations had no toxic effect against a macrophage cell line, not affecting the cell viability. In addition, after 48 hours of treatment, the BFO itself and its blend with Cetiol®-V (1:1v/v) at 200 µg.mL-1 were able to reduce the NO synthesis, and the IL-6 and TNF levels up to 35 ± 2%, 40 ± 6%, and 12 ± 3%, respectively. Therefore, these results provide unprecedented scientific evidence of the anti-inflammatory effect of BFO, suggesting its potential as a new candidate for the development of pharmaceutical products with antiinflammatory activity. [ABSTRACT FROM AUTHOR]

Constitutively expressed endothelial nitric oxide synthase (eNOS) is supposed to play a role in noise-induced nitric oxide (NO)-production. It is commonly known that intense noise exposure results in inducible NOS (iNOS) expression and increased NO-production, but knowledge about a contribution of the eNOS isoform is still lacking. Effects of noise exposure on eNOS immunolabeling were determined in male guinea pigs (n =24). For light microscopic analysis, 11 animals were exposed to 90 dB for 1 hr and 6 animals were used as controls. After exposure, eNOS immunostaining was performed on paraffin sections, and the staining intensities were quantified for 4 cochlear regions. For electron microscopic analysis, 2 animals were exposed for 2 hr to 90 dB and 5 animals were used as controls. The intensity of eNOS immunolabeling was found to be already comprehensively increased 1 hr after noise exposure to 90 dB. At the ultrastructural level, a clear increase in eNOS immunolabeling was found in microtubules-rich areas of cochlear cuticular structures. Hence, our findings indicate that the reticular lamina forming the endolymph–perilymph barrier at the apical side of the organ of Corti is involved in a fast intrinsic otoprotective mechanism of the cochlea. [ABSTRACT FROM AUTHOR]

Objective: To examine systemic vascular resistance index (SVRI), asymmetric (ADMA) and symmetric dimethylarginine (SDMA) levels in preeclampsia at different gestations. Methods: Twenty-four preeclamptic patients (14 at ≥ 34 weeks’) and 72 matched healthy controls were included. SVRI was calculated from impedance cardiography measurements. ADMA and SDMA levels were determined using enzyme-linked immunosorbent assay. Results: SVRI and SDMA were higher in preeclampsia overall, in early onset and late onset compared to controls. SVRI was correlated with ADMA and SDMA, respectively. Conclusions: Early-onset and late-onset preeclampsia are both characterized by increased systemic vascular resistance and elevated levels of nitric oxide synthesis inhibitors.

The incidence of diabetes mellitus is growing rapidly. The exact pathophysiology of diabetes is unclear, but there is increasing evidence of the role of the inflammatory response in both developing diabetes as well as its complications. Resolvins are naturally occurring polyunsaturated fatty acids that are found in fish oil and sea food that have been shown to possess anti‐inflammatory actions in several tissues including the kidneys. The pathways by which resolvins exert this anti‐inflammatory effect are unclear. In this review we discuss the evidence showing that resolvins can suppress inflammatory responses via at least five molecular mechanisms through inhibition of the nucleotide‐binding oligomerization domain protein 3 inflammasome, inhibition of nuclear factor κB molecular pathways, improvement of oxidative stress, modulation of nitric oxide synthesis/release and prevention of local and systemic leukocytosis. Complete understanding of these molecular pathways is important as this may lead to the development of new effective therapeutic strategies for diabetes and diabetic nephropathy. [ABSTRACT FROM AUTHOR]

• Chrysin attenuated the behavioral changes in PD model induced by 6-OHDA in aged-mice. • Chrysin protects against oxidative stress in PD model induced by 6-OHDA. • Chrysin protects neuroinflammation in PD model. Parkinson's disease (PD) is an age-related neurodegenerative disorder that severely affects quality of life of patients and their families. The flavonoid chrysin (5,7-dihydroxylflavone) is a naturally occurring flavone with several pharmacological activities, including anti-inflammatory and anti-oxidative. We investigated the effects of a 28-day chrysin treatment (10 mg/kg/day, i.g.) on a model of PD induced by 6-OHDA in aged (20-month old) mice. We found a protective effect of chrysin on behavioral and cognitive alterations (rotational behavior, passive avoidance and Barnes maze tests), nitric oxide synthesis (NO x), lipid peroxidation (HNE), glutathione levels (GSH), reactive species levels (RS), neuroinflammation (interleukin-1 beta - IL-1β and tumor necrosis factor alpha - TNF-α), Na+, K+-ATPase and nicotinamide adenine dinucleotide phosphate oxidase activity (NADPH oxidase) activities. In addition, chrysin protected against changes in striatal dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels. In conclusion, chrysin improved several behavioral, cognitive and neurochemical parameters in a relevant preclinical model of PD in aged mice. [ABSTRACT FROM AUTHOR]

Marine bacteria secrete exopolysaccharides (EPS) with unique structural and functional properties and serve as a source of newer bioactive biopolymers. This study reports an EPS produced by a marine bacterium identified as Alteromonas sp. PRIM-28 for its bioactivities. The EPS was characterised using standard methods and tested for its bioactivities using in vitro models. EPS-A28 is an anionic heteropolysaccharide with a molecular weight of 780 kDa and exists as triple helical structure in aqueous solution. Monosaccharide composition is mannuronic acid, glucose and N -acetyl glucosamine repeating units in the ratio 1:3.67:0.93. The FT-IR spectra showed the presence of sulphate, phosphate and uronic acid residues. The thermal analysis showed partial degradation of the EPS-A28 at 190 °C and 40% of residues were stable up to 800 °C. It showed biocompatibility and induced proliferation and migration of dermal fibroblasts (HDF) and keratinocytes. EPS-A28 could increase the S-phase of cell cycle. The proliferative property of the EPS-A28 was established by the increased expression of fibroblast proliferation marker (Ki-67) also its capability of binding to cell surface. It also induced nitric oxide and arginase synthesis in macrophages. These findings suggest that EPS-A28 can be potentially used as a multifunctional bioactive polymer in wound care. [ABSTRACT FROM AUTHOR]

The importance of l-arginine (Arg) and relatives, including l-homoarginine (hArg) and asymmetric dimethylarginine (ADMA), in humans infected with Helicobacter pylori (Hp) is little understood. ADMA is produced by asymmetric dimethylation of the guanidine group of Arg residues in certain proteins and is released by proteolysis. High concentrations of circulating free ADMA are considered a risk factor for morbidity and mortality in adults. This risk is considered to arise from the inhibition of the synthesis of nitric oxide (NO), which is a potent vasodilator and inhibitor of platelet aggregation. In the present study, we quantified by stable isotope dilution gas chromatography–mass spectrometry (GC–MS) the concentration of free (f) and total (t) ADMA, Arg, hArg, lysine (Lys) and the sum of citrulline (Cit) and ornithine (Orn) (6 M HCl, 20 h, 110 °C) in serum samples of apparently healthy elderly subjects (n = 27; age, 31–105 years) who were tested for Hp infection. Nine subjects (5 males, 4 females) were found to be Hp seropositive (Hp+) and 18 subjects (8 males, 9 females) were found to be Hp seronegative (Hp‒). Proteinic (p) concentrations were determined by difference. fADMA (0.493 ± 0.068 vs 0.466 ± 0.081 µM, P = 0.382), pADMA (113 ± 73 vs 76 ± 59 nM, P = 0.169) and tADMA (0.606 ± 0.126 vs 0.543 ± 0.121 µM, P = 0.280) serum concentrations were found not to differ between the Hp+ and Hp− subjects. Serum concentrations of fArg (162 ± 30 vs 177 ± 36 µM, P = 0.471), fhArg (1.600 ± 0.638 vs 1.831 ± 0.742 µM, P = 0.554), and fLys (388 ± 170 vs 395 ± 149 µM, P = 0.700) also did not differ statistically between Hp+ and Hp− subjects. tArg (12.4 ± 1.49 vs 13.0 ± 1.33 mM, P = 0.190), tLys (23.0 ± 2.65 vs. 23.9 ± 2.66 mM, P = 0.456) and tCit + Orn (2.53 ± 0.76 vs 2.63 ± 0.85 mM, P = 0.817) did not differ between Hp+and Hp‒ subjects as well. phArg concentration was close to the limit of quantitation of the method (Hp+: 30 ± 210 nM; Hp−: 42 ± 205 nM), suggesting that hArg is virtually absent in serum proteins of the investigated subjects. pCit + Orn did not differ between infected and non-infected subjects. Our study suggests that Hp infection is not associated with elevated asymmetric dimethylation and citrullination of Arg proteins present in the serum or with the hArg synthesis from free Arg in elderly subjects. However, asymmetric Arg dimethylation was found to correlate inversely with Arg citrullination in Hp− (r2 = 0.408, P = 0.004) but not in Hp+ (r2 = 0.065, P = 0.506), with Arg citrullination decreasing and Arg asymmetric dimethylation increasing with subjects' age. [ABSTRACT FROM AUTHOR]

Highlights • Endocannabinoids and nitric oxide interact in the dorsomedial hypothalamus to regulate appetite. • 2-AG increases food intake in young male rats when administered into the DMH with l -arginine. • Type I cannabinoid receptors and nitric oxide synthesis are required for the increase in appetite. • Neither 2-AG nor l -arginine altered food intake when administered independently. • Anandamide failed to affect food intake when administered alone or in combination with l -arginine. Abstract The dorsomedial nucleus of the hypothalamus (DMH) is an important appetite regulatory center in the brain. In young rats, neural communication in the DMH is modulated by two interacting signals: endocannabinoids (eCBs) and nitric oxide (NO), both of which are known to modulate appetite. It remains unknown, however, whether eCBs and NO interact in the DMH to regulate food intake and body weight in young rats. We developed stereotaxic coordinates for the DMH in young, male Sprague-Dawley rats and conducted surgeries to implant bilateral guide cannulas for microinjection of vehicle, eCBs [2-arachidonylglycerol (2-AG) or anandamide]; NO (via the precursor l -arginine), or a combination of the two, with and without prior subcutaneous injections of drugs to block cannabinoid receptors or NO synthesis. Food intake and body weight of animals were measured two hours following the injection and brains were subsequently removed and sliced to verify placement of the cannulas relative to the DMH. Here we show that 2-AG, when administered in combination with l -arginine, significantly increased food intake and body weight, an effect that required type I cannabinoid receptors and NO synthesis. 2-AG and l -arginine had no effect on food intake or body weight when administered into the DMH independently. Anandamide also failed to affect these parameters when administered alone or with l -arginine. Together, these data suggest that 2-AG and NO interact in the DMH to increase food intake in young male rats and provide insight into a possible mechanism by which 2-AG increases appetite. [ABSTRACT FROM AUTHOR]

Ischemia postconditioning (PTC) can reduce myocardial ischemia/reperfusion injury. However, the effectiveness of PTC cardioprotection is reduced or lost in diabetes and the mechanisms are largely unclear. Hyperglycemia can induce overexpression of inducible nitric oxide synthesis (iNOS) in the myocardium of diabetic subjects. However, it is unknown whether or not iNOS especially its overexpression plays an important role in the loss of cardioprotection of PTC in diabetes. C57BL6 and iNOS−/− mice were treated with streptozotocin to induce diabetes. Part of diabetic C57BL6 mice were also treated with an iNOS specific inhibitor, 1400 W. Mice were subjected to myocardial ischemia/ reperfusion with/without PTC. The hemodynamic parameters, plasma levels of cardiac troponin T (cTnT), TNF-α, IL-6 and nitric oxide (NO) were monitored. The myocardial infarct size, superoxide anion (O 2 −) generation, nitrotyrosine production and apoptosis were measured. The expression of phosphorylated Akt, endothelial NOS (eNOS), iNOS and Erk1/2 in ischemic heart were detected by immunoblot analysis. In diabetic C57BL6 and iNOS−/− mice, the post-ischemic hemodynamics were impaired, the cTnT, TNF-α, IL-6 level, myocardial infarct size, apoptotic index, O 2 − and nitrotyrosine generation were increased and the Akt/eNOS signal pathways were inhibited. PTC improved hemodynamic parameters, reduced cTnT level, myocardial infarct size, apoptotic index, O 2 − and nitrotyrosine generation and activated Akt/eNOS and Erk1/2 signal pathways in both non-diabetic C57BL6 and iNOS−/− mice as well as diabetic iNOS−/− mice, but not in diabetic C57BL6 mice. PTC also increased NO production in both non-diabetic and diabetic C57BL6 and iNOS−/− mice, and enhanced iNOS expression in non-diabetic C57BL6 mice. 1400 W restored the cardioprotection of PTC in diabetic C57BL6 mice. Our data demonstrated that PTC reduced myocardial ischemia/reperfusion injury in non-diabetic mice but not C57BL6 diabetic mice. Deletion of iNOS restored the cardioprotection of PTC in diabetic mice. Our findings suggest that iNOS plays a key role in the reduction of cardioprotection of PTC in diabetes and may provide a therapeutic target for diabetic patients. • iNOS overexpression reduced the cardioprotection of PTC in diabetic mice. • Deletion of iNOS restored the cardioprotection of PTC in diabetic mice by activating Akt/eNOS and Erk1/2. • PTC restored its protective effect in iNOS-/- diabetic mice by decreasing of superoxide anion and nitrotyrosine formation. [ABSTRACT FROM AUTHOR]

The central nervous system (CNS) is the most injury-prone part of the mammalian body. Any acute or chronic, central or peripheral neurological disorder is related to abnormal biochemical and electrical signals in the brain cells. As a result, ion channels and receptors that are abundant in the nervous system and control the electrical and biochemical environment of the CNS play a vital role in neurological disease. The N-methyl-d-aspartate receptor, 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl) propanoic acid receptor, kainate receptor, acetylcholine receptor, serotonin receptor, α2-adrenoreceptor, and acid-sensing ion channels are among the major channels and receptors known to be key components of pathophysiological events in the CNS. The primary amine agmatine, a neuromodulator synthesized in the brain by decarboxylation of l-arginine, can regulate ion channel cascades and receptors that are related to the major CNS disorders. In our previous studies, we established that agmatine was related to the regulation of cell differentiation, nitric oxide synthesis, and murine brain endothelial cell migration, relief of chronic pain, cerebral edema, and apoptotic cell death in experimental CNS disorders. In this review, we will focus on the pathophysiological aspects of the neurological disorders regulated by these ion channels and receptors, and their interaction with agmatine in CNS injury. [ABSTRACT FROM AUTHOR]

Obesity and type 2 diabetes mellitus (T2DM) are diseases associated with hypertension and metabolic alterations. A significant group of patients present both obesity and T2DM, a condition defined as diabesity. One of the metabolic features in these conditions is the clinical presentation of insulin resistance. Several tissues, including the liver, skeletal muscle, and vasculature, and patients with T2DM, gestational diabetes, and obesity show insulin resistance. The vascular effect of insulin, including vasodilation, is mainly mediated by the generation of nitric oxide. Several mechanisms are proposed to elucidate the origin of insulin resistance; nevertheless, a common finding is the endothelial dysfunction in these diseases. Endothelial cells from subjects with obesity show reduced nitric oxide synthesis, an effect that is unaltered by insulin. Individuals with T2DM show a misbalance between the synthesis, release, and biological actions of vasodilators and vasoconstrictors such as nitric oxide and endothelin-1. However, whether these mechanisms are involved in the vascular alterations seen in patients with diabesity is unclear. In this review, we discussed the modifications on insulin signalling, insulin resistance in obesity and T2DM, and the reported changes in signalling pathways in diabesity. [ABSTRACT FROM AUTHOR]

Abstract Nitric oxide (NO), produced by nitric oxide synthases (NOS) from L-arginine, plays important roles in a wide range of physiological processes. However, little is known about ectothermic species. To investigate the response of NO/NOS system in adaptation to different altitudes in Phrynocephalus genus, the red tail toad-headed lizard Phrynocephalus erythrurus that live at 4500–5300 m on the Qinghai-Tibet Plateau and another low altitude living lizard Phrynocephalus przewalskii were selected in the present study. The results of mRNA expression and activity of NOSs, as well as NO metabolite levels in different tissues of the two lizards indicate that nNOS mRNA levels in cardiac and skeletal muscle were notably elevated in P. erythrurus , and iNOS expression was also increased markedly (up to 4-fold) in cardiac muscle. There was no significant difference in eNOS mRNA level in tested tissues between two species. However, the total NOS activity in skeletal muscle of P. erythrurus was slightly lower than that of P. przewalskii (p <.05) while no difference in other tissues. Similarly, lower iNOS activity (p <.01) was found in cardiac and skeletal muscle in P. erythrurus compared to P. przewalskii. In addition, the NO metabolite levels were dramatically lower in P. erythrurus in all tested tissues. We propose that higher nNOS and iNOS mRNA expression, lower iNOS activity and NO metabolite levels may represent physiological characteristics in nitric oxide system, which may contribute to high-altitude adaptation in P. erythrurus. Highlights • The red tail toad-headed lizard Phrynocephalus erythrurus has known to be the highest living lizard in the world. • We examined the NOSs mRNA expression, NOSs activity and NO metabolite levels between high and low altitudes living lizard. • These changes may represent physiological characteristics of adaptation to the extreme environment in P. erythrurus. [ABSTRACT FROM AUTHOR]

It is well known that the lipotoxic mechanism of palmitic acid (PA), a main constituent of triglyceride, is dependent on reactive oxygen species (ROS). Recently, it has also been reported that PA is an autophagy inducer. However, the causal association and underlying mechanism of induced autophagy and ROS in PA toxicity remain unclear. The present study demonstrates for the first time that PA-induced autophagy enhances ROS generation via activating the calcium ion/protein kinase Cα/nicotinamide adenine dinucleotide phosphate oxidase 4 (Ca2+/PKCα/NOX4) pathway in human umbilical vein endothelial cells (HUVECs). It was revealed that PA treatment resulted in a significant increase in ROS generation and autophagic activity, leading to endothelial dysfunction as indicated by downregulated nitric oxide synthesis, decreased capillary-like structure formation and damaged cell repair capability. Furthermore, PA effectively activated the Ca2+/PKCα/NOX4 pathway, which is indicative of upregulated cytosolic Ca2+ levels, activated PKCα and increased NOX4 protein expression. 3-Methyladenine was then used to inhibit autophagy, which significantly reduced PA-induced ROS generation and blocked the Ca2+/PKCα/NOX4 pathway. The endothelial dysfunction caused by PA was ameliorated by downregulating ROS generation using a NOX4 inhibitor. In conclusion, PA-induced autophagy contributes to endothelial dysfunction by increasing oxidative stress via the Ca2+/PKCα/NOX4 pathway in HUVECs. [ABSTRACT FROM AUTHOR]

Highlights • Subchronic Cd intoxication causes inflammation and apoptosis in the aorta of rats. • Dietary soy does not affect Cd bioaccumulation in the aorta tissue. • Dietary soy protects against pro-inflammatory effects of Cd intoxication in aorta. • Dietary soy reduces Cd-induced apoptosis in aorta by increasing Bcl-2 expression. Abstract Cadmium (Cd) exposure has been associated with an increased risk of cardiovascular diseases. The diet is a modifiable source of protecting or damaging factors that may affect this risk. Herein we tested the hypothesis that a soybean-based diet (SBD) protects the vascular wall of the aorta against Cd-induced pro-inflammatory and pro-apoptotic effects. To test this hypothesis, we fed male Wistar rats for 60 days with a casein-based diet (CBD) or an SBD. These animals were also exposed to tap-water without (CBD-Co/SBD-Co) or with 15(CBD-15Cd/SBD-15Cd) or 100 (CBD-100Cd/SBD-100Cd) ppm of Cd. Inflammatory parameters (mRNAs and/or proteins) were measured in thoracic aorta tissue. These included inducible and endothelial nitric oxide synthases, cyclooxygenase-2, intracellular-adhesion molecule-1, and vascular cell-adhesion molecule-1. As pro-apoptotic parameters, we measured Bax and Bcl-2 mRNA/protein, as well as TUNEL positive cells in the aorta tissue. Compared to CBD-Co, inflammatory and apoptosis markers increased in the aorta with the concentration of Cd in the drinking water. These effects were not observed in either SBD-15Cd or SBD-100Cd, which were similar to CBD-Co. Cd content in serum and in aortas from animals fed CBD-Co/SBD-15Cd or CBD-Co/SBD-100Cd were similar suggesting that, if any, the effect of SBD is not due to changes in Cd bioaccumulation, but due to secondary effects linked to the composition of the dietary soybean flour. Our findings are consistent with a protective effect of an SBD against Cd-induced inflammation and apoptosis in the thoracic aorta in a rat model. [ABSTRACT FROM AUTHOR]

Calix[4]arene‐based molecules hold great promise as candidate sensors and storage materials for nitric oxide (NO), owing to their unprecedented binding affinity for NO. However, the structure of calix[4]arene is complicated by the availability of four possible conformers: 1,3‐alternate, 1,2‐alternate, cone, and partial cone (paco). Whilst complexes of NO with several of these conformers have previously been established, the 1,2‐alternate conformer complex, that is, [1,2‐alter⋅NO]+, has not been previously reported. Herein, we determine the crystal structure of the NO complex with the 1,2‐alternate conformer for the first time. In addition, we have also found that the 1,2‐alternate and 1,3‐alternate conformers can combine with two NO molecules to form stable bis(nitric oxide) complexes. These new complexes, which exhibit remarkable binding capacity for the construction of NO‐storage molecules, were characterized by using X‐ray crystallography and NMR, IR, and UV/Vis spectroscopy. These findings will extend our understanding of the interactions between nitric oxide and cofacially and non‐cofacially arrayed aromatic rings, and we expect them to aid in the design and development of new supramolecular sensors and storage materials for NO with high capacity and efficacy. Dr. NO: Two new calix[4]arene‐based bis(nitric oxide) complexes with 1,2‐ and 1,3‐alternate conformers were isolated and characterized by using spectroscopy and X‐ray crystallography. [ABSTRACT FROM AUTHOR]

Aim: No-reflow phenomenon is an important complication of primary percutaneous coronary intervention. Several variants in the endothelial nitric oxide synthase gene, which reduce endothelial nitric oxide synthase activity, are a risk factor for coronary heart disease. However, its role in no-reflow phenomenon has not yet been revealed. This study aimed to investigate whether there is a relationship between endothelial nitric oxide synthase Glu298Asp gene variant and the development of coronary no-reflow phenomenon in patients with ST elevation myocardial infarction. Material/Methods: The study was conducted among 116 patients undergoing primary percutaneous coronary intervention for ST elevation myocardial infarction. Group 1 included 52 ST elevation myocardial infarction patients undergoing no-reflow phenomenon as a study group. Group 2 comprised 64 ST elevation myocardial infarction patients without no-reflow phenomenon as a control group. Endothelial nitric oxide synthase was tested using polymerase chain reaction--restriction fragment length variant. Results: The prevalence of TT genotype of endothelial nitric oxide synthase Glu298Asp gene variant was found to be significantly higher in patients developing coronary no-reflow when compared to those without no-reflow (p = 0.016; 11.54% vs. 1.56%) (OR = 10.85, 95% CI = 1.22-96.39). However, a similar association for the heterozygous GT genotype of endothelial nitric oxide synthase Glu298Asp gene variant was not observed between the two groups. Conclusions: The results of this preliminary study indicate that there is an association between Glu298Asp variant in endothelial nitric oxide synthase gene and the development of no-reflow phenomenon in ST elevation myocardial infarction. The presence of homozygous TT allele may contribute to tendency to the development of no-reflow phenomenon. [ABSTRACT FROM AUTHOR]

The effect of citrulline and ammonium chloride on the nitric oxide formation by peritoneal macrophages and liver tissue cells was studied using ESR spectroscopy. In ex vivo models, the incubation of cells capable of expressing inducible NO synthase (iNOS) with interferon-γ resulted in a moderate increase in the amount of hemoglobin–nitric oxide nitrosyl complexes (Heme–NO NCs), whereas incubation with l-citrulline and ammonium chloride increased the amount of Heme–NO NCs by an order of magnitude. It was assumed that a separate cycle of L-arginine and nitric oxide synthesis exists in the peritoneal macrophages and liver cells, with the major participants of the cycle being the inducible NO synthase enzyme (iNOS) and enzymes that synthesize L-arginine from L-citrulline and a nitrogen source. Functioning of this cycle makes immunocompetent cells with iNOS able to produce NO for a long time and in large amounts. [ABSTRACT FROM AUTHOR]

Background: The sepsis pathology remains an enormous medical problem globally because morbidity and mortality remain unacceptably high in septic patients despite intense research efforts. The economic and societal burden of sepsis makes it the most pressing patient care issue in the US and worldwide. Sepsis is a dysregulated immune response normally initiated by an infection. The need for an early, accurate, and reliable biomarker test to detect the onset of sepsis and for a targeted sepsis therapy is widely recognized in the biomedical community. Content: This report reviews the published findings relevant to microvesicle-associated inducible nitric oxide synthase (MV-A iNOS) as a novel plasma biomarker for the onset of sepsis, including human clinical studies and animal studies. Plasma iNOS as both a standalone test and 1 of the components of a novel panel of biomarkers to stage the progression of sepsis is presented and discussed in comparison with other biomarkers and other proposed panels of biomarkers for sepsis. Summary: The data strongly support the concept that extracellular plasma MV-A iNOS in circulating microvesicles is centrally involved in the initiation of sepsis, and a diagnostic test based on plasma iNOS can serve as an early presymptomatic warning signal for the onset of sepsis. A novel panel of plasma biomarkers comprising iNOS, pro-interleukin-18, pro-interleukin-33, and regenerating protein 1-α is proposed as a multianalyte presymptomatic method to stage the onset of sepsis for improved, prompt, data-driven patient care. [ABSTRACT FROM AUTHOR]

Abstract To develop multifunctional drugs, a series of celastrol/NO donor hybrids were designed, synthesized and evaluated. The detection of NO release amounts showed that the more NO of these hybrids released, the more tumor cells were inhibited. 11b , which released the highest level of NO in vitro , exhibited superior potency (IC 50 = 0.48 ± 0.06 μM) compared to the other compounds. Further pharmacological studies showed that 11b induced dysregulations of the Hsp90 clients (Akt and Cdk4), apoptosis, and cell cycle arrested at G 0 /G 1 phase against A549 cells. These results suggested that inhibition of Hsp90 and release of NO was synergistic in cancer cells. Overall, the NO-releasing capacity and the inhibition of Hsp90 pathway signaling might explain the potent anti-proliferative activities of these compounds. Graphical abstract A series of celastrol/NO donor hybrids were designed, synthesized and evaluated. 11b , which released the highest level of NO in vitro , exhibited the best antiproliferative effects. The results suggested that inhibition of Hsp90 and release of NO was synergistic in cancer cells. Image 1 Highlights • A series of celastrol/NO donor hybrids were designed, synthesized and evaluated. • 11b exhibited superior potency compared to the other compounds. • 11b induced degradation of the Hsp90 clients (Akt and Cdk4), apoptosis and the cell cycle arrested at the G 0 /G 1 phase in A549 cells. [ABSTRACT FROM AUTHOR]

Abstract Marsdenia tenacissima exhibits biological activity with heat-clearing and detoxifying properties, relieving coughs and asthma and exerting anticancer and anti-HIV effects. Tenacissioside H (TH) is a Chinese medicine monomer extracted from the dried stem of Marsdenia tenacissima. We investigated the in vivo anti-inflammatory activity of TH using three different zebrafish inflammation models: local inflammation induced by tail cutting, acute inflammation induced by CuSO 4, and systemic inflammation induced by lipopolysaccharide (LPS). Real time-polymerase chain reaction (RT-PCR) was used to elucidate the mechanism of TH action against LPS-induced inflammatory responses. Our results showed TH significantly reduced the number of macrophages in the injured zebrafish tail, inhibited CuSO 4 -induced migration of macrophages toward the neural mound, and decreased the distribution of macrophages in tail fin compared to LPS-treated group. Furthermore, TH inhibits LPS-induced inflammation responses in zebrafish by modulating the nuclear factor κB (nf-κb) and p38 pathways to regulate inflammatory cytokines, such as tumor necrosis factor-α (tnf-α), cyclooxygenase (cox-2), interleukin-1b (il-1b), interleukin-8 (il-8), interleukin-10 (il-10), nitric oxide synthase (nos2b) and prostaglandin E synthase (ptges). In conclusion, TH possesses anti-inflammation activity via the regulation of the nf-κb and p38 pathways. This finding provides a reference for the clinical application of Xiaoaiping (the trade name of Marsdenia tenacissima extract). Graphical abstract Image 1 Highlights • TH significantly inhibits inflammatory responses in zebrafish in three different inflammatory models. • TH could down-regulate inflammatory cytokines against LPS-induced inflammatory responses, such as tnf-α and nos2b. • TH inhibits LPS-induced inflammation responses in zebrafish by modulating the nuclear factor κB and p38 pathways. [ABSTRACT FROM AUTHOR]

Abstract Twelve previously undescribed withanolides, including three uncommon chemotypes of aglycones, daturafolisides (J-L), and six common structures, daturafolisides (M-U), as well as one known withanolide were isolated from the leaves of Datura metel L. Their structures were elucidated by interpretation of spectroscopic data (1D, 2D NMR and CD), HRESIMS experiments and comparison with published data for similar compounds. These isolated compounds were evaluated for their inhibitory activities on nitric oxide production. The IC 50 values of daturafoliside L, daturafoliside M, and daturafoliside T were between 9.37 and 18.64 μM, while daturafoliside K, daturafoliside R, and daturametelin A had IC 50 values of 22.83–33.36 μM. Herein, three proposed biosynthetic pathways for uncommon structures daturafolisides J-L were discussed. These constituents found in the leaves of Datura metel L. may be a good source of bioactive substances, making contributions to the sustainable utilization of this plant resources. Graphical abstract Image 1 Highlights • The leaves of Datura metel L. yielded twelve undescribed withanolides (daturafolisides J-U). • Their structures were established by NMR, UV, IR spectroscopy and by HRESIMS. • Daturafolisides J-L possess three unique structure moieties in rings A and B. • The anti-inflammatory potential of all these compounds were evaluated on Murine RAW 264.7 macrophages. • Three withanolides showed pronounced effects against NO production. [ABSTRACT FROM AUTHOR]

Inhibition of nitric oxide (NO) production can influence blood pressure regulation and increase hypertension. Asymmetric dimethylarginine, ADMA, an analogue of L -arginine, can inhibit NO synthesis, impair endothelial function, and is a risk marker of cardiovascular diseases. Homocysteine (Hcy) level affects oxidative stress production of reactive oxygen species (ROS) in hypertension and also influences changes in signaling and cell damage. The present study was focused on experimental effects of exogenous NOS inhibitors and their effect on ADMA, an endogenous NOS inhibitor, homocysteine and ROS production measured as reactive oxidative metabolites (ROM). We compared effects of the two potential exogenous NO-inhibitors: N G -nitro L -arginine methyl ester (L-NAME) and 7-nitroindazole (7-NI). Levels of ADMA, Hcy, ROM and total thiols (TTL) were not changed in the L-NAME group. With 7-NI administration, we observed unchanged NOS activity in the left ventricle and a pronounced decrease of ADMA and Hcy levels, accompanied by ROM over-production in plasma. TTL/ROM ratio was more favorable than in the L-NAME group. We observed that 7-NI, an exogenous NOinhibitor, can decrease and improve the levels of ADMA, Hcy, and ROM, and increase TTL/ROM ratio in the plasma of spontaneously hypertensive rats. [ABSTRACT FROM AUTHOR]

Abstract Background Rivaroxaban, a widely used factor Xa inhibitor in reducing stroke in atrial fibrillation (AF) patients has multiple biological effects with activation of protease-activated receptor (PAR) signaling. Atrial fibrosis plays a critical role in the pathophysiology of AF. In this study, we evaluated whether rivaroxaban regulates atrial fibroblast activity and its underlying mechanisms. Methods and results Migration, proliferation analyses, nitric oxide (NO) production assay, calcium fluorescence imaging, and western blots were conducted in human atrial fibroblasts with or without rivaroxaban (100 nmol/L or 300 nmol/L) and co-administration of L-NAME (L-NG-nitro arginine methyl ester, 100 μmol/L), EGTA (Ethylene glycol tetra-acetic acid, 1 mmol/L), thrombin (0.5 U/mL), PAR1 agonist peptide (TFLLR-NH2, 100 μmol/L), PAR1 inhibitor (SCH79797, 0.5 μmol/L) and PAR2 inhibitor (GB83, 10 μmol/L). Atrial fibrosis was examined in isoproterenol (100 mg/kg, subcutaneous injection)-treated rats with or without rivaroxaban (10 mg/kg/day orally for 14 consecutive days). Rivaroxaban reduced the migration, pro-collagen type I production, and proliferation of atrial fibroblasts. Rivaroxaban decreased phosphorylated endothelial NO synthase (eNOS) (Thr 495, an inhibitory phosphorylated site of eNOS), and calcium (Ca2+) entry, and increased NO production. Moreover, L-NAME blocked the effects of rivaroxaban on fibroblast collagen and NO production. In the presence of EGTA, the migratory capability was similarly decreased in atrial fibroblasts with and without treatment with rivaroxaban (100 nmol/L), which suggests that rivaroxaban decreases migratory capability of atrial fibroblasts by inhibiting Ca2+ entry. Additionally, rivaroxaban significantly attenuated the effects of thrombin, and TFLLR-NH2 on migratory, proliferative, and pro-collagen type I production capability in atrial fibroblasts. SCH79797 or GB83 decreased pro-collagen type I production, migration, and proliferation capability in fibroblasts, but combined SCH79797 or GB83 with and without rivaroxaban had similar fibroblast activity. Moreover, rivaroxaban significantly decreased atrial fibrosis in isoproterenol-treated rats. Conclusions Rivaroxaban (100–300 nmol/L) regulates atrial fibroblast activity and atrial fibrosis by increasing NO production and decreasing Ca2+ entry through inhibition of PAR signaling. Highlights • Rivaroxaban decreases the activity of human atrial fibroblasts. • Rivaroxaban reduces Ca2+ entry and increases NO production in atrial fibroblasts. • Rivaroxaban attenuates the effects of thrombin or PAR agonists on fibroblasts • Rivaroxaban reduces atrial fibrosis and atrial size in isoproterenol-treated rats. • PAR 1, 2 signaling contributes to the effects of rivaroxaban on fibroblasts. [ABSTRACT FROM AUTHOR]

Circulating endothelial progenitor cells (EPCs) are a subtype of hematopoietic stem cells, which can differentiate into endothelial cells and restore endothelial function. However, high glucose decreases the number and impairs the function of EPCs. A previous study showed that thymosin β4 (Tβ4), a pleiotropic peptide beneficial for multiple functions of various types of cells, could promote EPC migration and dose-dependently upregulate the phosphorylation of Akt and endothelial nitric oxide synthesis signaling (eNOS). In present study, the hypothesis that Tβ4 can improve glucose-suppressed EPC functions via the Akt/eNOS signaling pathway and restores the production of nitric oxide (NO) is investigated. EPCs were isolated from the peripheral blood of healthy volunteers and formed a cobblestone shape after 3-4 weeks of cultivation. Then, EPCs were treated with high concentrations of glucose (25 mM) for 4 days and administrated with Tβ4 for further study. Transwell migration and tube formation assays were performed to access the migratory and angiogenic ability of EPCs. In addition, the quantity of Akt, eNOS and the concentration of nitric oxide (NO) was investigated. Functional studies showed that high concentrations of glucose significantly suppressed EPC function, while this adverse effect was reversed by the administration of Tβ4. In addition, Akt small interfering (si)RNA and eNOS siRNA were demonstrated to reduce the protective effect of Tβ4 against glucose-impaired EPC functions. These findings suggest that Tβ4 improves glucose-impaired EPC functions via the Akt/eNOS signaling pathway. [ABSTRACT FROM AUTHOR]

Summary Background & aims Plasma arginine (ARG) levels are reduced in breast cancer, suggesting diminished systemic ARG availability. ARG and its product nitric oxide (NO) are important in early postoperative recovery due to its roles in immune function and wound healing. It remains unclear whether major surgery further diminishes systemic ARG availability due to enhanced ARG catabolism and/or insufficient endogenous ARG synthesis negatively affecting NO synthesis in patients with early stage breast cancer. Methods In 9 women with early stage breast malignancy and 9 healthy women with genetic predisposition to breast cancer, whole body ARG and citrulline (CIT) rates of appearances were measured to determine their production rates prior to and within 24 h after major breast surgery by stable isotope methodology in the postabsorptive and postprandial state. The conversions of CIT > ARG, ARG > CIT, and ARG > Urea (markers of de novo ARG and NO synthesis, arginase activity, respectively), and ARG clearance (reflecting ARG disposal capacity) were calculated. Results Prior to surgery, plasma ARG, CIT and glutamine concentrations were lower in cancer (P < 0.05) but no differences were found in the rate of appearances of ARG, CIT and their conversions. Surgery increased ARG clearance and reduced CIT rate of appearance, conversion of CIT > ARG (P < 0.001), and plasma ARG, CIT, ornithine concentrations (P < 0.001). Furthermore, postprandial increase in ARG > CIT conversion (P < 0.05), plasma ARG (P < 0.001) and CIT (P = 0.06) concentrations were lower after surgery. The cancer group had lower values for postprandial increase in ARG > CIT conversion, plasma CIT (P < 0.05) and glutamine concentrations (P = 0.08). Conclusions Major surgery in early stage breast cancer further reduces systemic ARG availability in the early phase of recovery due to a combined process of increased ARG catabolism and impaired endogenous ARG synthesis. The suppressed postprandial NO increase in early stage cancer suggests that specific nutritional approaches are advised to increase ARG availability after major surgery although the effects on postoperative recovery remain unclear. This trial was registered at clinicaltrials.gov as NCT00497380. [ABSTRACT FROM AUTHOR]

Highlights • Our study proved that Big-leaf mulberry could decrease WIRS-induced mouse gastric damage. • INOS and eNOS appeared to exert an important action in the mouse stomach exposed to WIRS. • It is the frist study to use mulberry leaves to examine its gastroprotective action in WIRS-induced injury to date. Abstract Acute gastric mucosal injuries are serious clinical problems worldwide and are principally found with different types of stresses in animals. A constant challenge is to find original plant products that can combat stress. In the present study, we examined the effects of big-leaf mulberry extracts on stomach injury, and the activity of nitric oxide synthases (NOS) and total antioxidant activity (TAO) in the gastric mucosae of mice during water immersion and restraint stress (WIRS). Our data showed that WIRS-exposed mice produced several injuries and showed an enhanced iNOS, reduced eNOS activity, and decreased TAO activity in the stomach, whereas pretreatment with big-leaf mulberry extracts increased TAO activitiy. The data from our immunohistochemical study indicated that both iNOS and eNOS were expressed in parietal cells and blood vessels, while nNOS was only weakly expressed in parietal cells. In conclusion, our findings suggested that big-leaf mulberry mitigated WIRS-induced stomach injuries, and NOS signaling may play important roles in the mouse stomach during the recovery process. [ABSTRACT FROM AUTHOR]

Pharmacological manipulations of constitutive nitric oxide (cNO) levels have been shown to have variable effects on Na absorption in vivo and in vitro in different tissues. Species differences, untoward in vivo effects (e.g. ENS, blood flow) and pharmacological non-specificity may account for these confounding observations. Thus, to directly and specifically determine the effect of cNO on brush border membrane Na/H exchange (NHE3) and Na-dependent glucose co-transport (SGLT-1), we inhibited cNO synthase (NOS3) with its siRNA in rat small intestinal epithelial cells (IEC-18) in vitro . As expected, intracellular cNO levels were reduced in siRNA NOS3 transfected cells. In these cells, SGLT-1 was significantly reduced compared to control. In contrast, NHE3 was significantly increased in siRNA NOS3 transfected cells. To determine if SGLT-1 changes were secondary to altered Na/K-ATPase, its activity was measured and found to be increased in NOS3 silenced cells. The mechanism of inhibition of SGLT-1 was secondary to diminished affinity of the co-transporter for glucose in NOS3 silenced cells. In contrast, the mechanism of stimulation of NHE3 is by increasing BBM exchanger numbers in siRNA NOS3 cells while the affinity was unaffected. Western blot studies of immunoreactive BBM proteins also confirmed the kinetic studies. All these data indicates that direct and specific inhibition of NOS3 with its siRNA inhibits SGLT-1 while stimulating NHE3 in the BBM. Thus, cNO uniquely and compensatorily regulates BBM NHE3 and SGLT-1 to maintain cellular Na homeostasis and these unique alterations by cNO are mediated by its intracellular 2nd messenger cGMP. [ABSTRACT FROM AUTHOR]

Oral cancer is a major head and neck cancer that is reported to be causally associated with genetic factors and environmental carcinogens. Endothelial nitric oxide synthase (eNOS) was reported to modulate carcinogenesis and progression through nitric oxide (NO) production. Genetic polymorphisms in the eNOS gene can regulate its transcription and further mediate NO production. The purpose of this study was to explore the influences of eNOS gene polymorphisms combined with environmental carcinogens on the predisposition for oral cancer. Two single-nucleotide polymorphisms (SNPs) of the eNOS gene, −786 T > C (rs2070744) and 894G > T (rs1799983), were genotyped in 1200 controls and 1044 patients with oral cancer using a TaqMan-based real-time polymerase chain reaction (PCR). We found that patients who carried the −786 T > C TC genotype were at higher risk for developing an advanced clinical stage (stage III/IV) compared to those with the −786 T > C TT genotype; however, there was no significant association of the two individual SNPs with oral cancer between patients and the control group. According to behavioral exposure to environmental carcinogens, the presence of these two eNOS SNPs combined with tobacco use and/or betel quid chewing profoundly enhanced the risk of oral cancer. Moreover, carriers with the betel quid-chewing habit who had haplotypes of the two eNOS SNPs more easily developed oral cancer. These results indicated an involvement of −786 T > C polymorphisms in the progression of oral cancer and support the interaction between eNOS gene polymorphisms and environmental carcinogens as a predisposing factor of oral carcinogenesis. [ABSTRACT FROM AUTHOR]

Glioblastoma multiforme (GBM) is a devastating brain cancer with no curative treatment. Targeting Nitric Oxide (NO) and glutamatergic pathways may help as adjunctive treatments in GBM. NO at low doses promotes tumorigenesis, while at higher levels (above 300 nM) triggers apoptosis. Gliomas actively secrete high amounts of glutamate which activates EGR signaling and mediates degradation of peritumoral tissues via excitotoxic injury. Memantine inhibits NMDA-subtype of glutamate receptors (NMDARs) and induces autophagic death of glioma cells in vitro and blocks glioma growth in vivo . Nitro-memantines may exert further benefits by limiting NMDAR signaling and by delivery of NO to the areas of excessive NMDAR activity leading NO-accumulation at tumoricidal levels within gliomas. Due to the duality of NO in tumorigenesis, agents which attenuate NO levels may also act beneficial in treatment of GBM. Nitrone compounds including N - tert -Butyl-α-phenylnitrone (PBN) and its disulfonyl-phenyl derivative, OKN-007 suppress free radical formation in experimental cerebral ischemia. OKN-007 failed to show clinical efficacy in stroke, but trials demonstrated its high biosafety in humans including elderly subjects. PBN inhibits the signaling pathways of NF-κB, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX). In animal models of liver cancer and glioblastoma, OKN-007 seemed more efficient than PBN in suppression of cell proliferation, microvascular density and in induction of apoptosis. OKN-007 also inhibits SULF2 enzyme, which promotes tumor growth via versatile pathways. We assume that nitromemantines may be more beneficial concomitant with chemo-radiotherapy while nitrones alone may act useful in suppressing basal tumor growth and angiogenesis. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO), an intercellular signaling molecule is relevant for circulatory autonomic control. Brain NO synthase (NOS) and NO levels were downregulated in pathological conditions, but rescued after exercise training. We hypothesized that exercise training was also able to improve NO modulation within the hypothalamic paraventricular nucleus (PVN) of healthy rats. Male Wistar rats were submitted to two 4-weeks protocols: i) swimming training (T) or kept sedentary (S), ii) l -arginine (62,5 mg/mL, 1 mL/day p. o. ) or vehicle supplementation. Rats underwent stereotaxic surgery (PVN bilateral guide cannulas) and chronic catheterization of artery/vein. Arterial pressure (AP), heart rate (HR) and baroreflex sensitivity were recorded in conscious rats at rest and following a selective nNOS inhibitor (Nw-Propyl- l -Arginine, 4 nmol/100 nL) within the PVN. Rats were deeply anesthetized for brain perfusion/harvesting after respiratory arrest. In separate groups (T and S, l -arginine and Vehicle supplemented) not submitted to PVN cannulation, fresh and fixed brains were obtained for gene and protein nNOS expression (qPCR and immunohistochemistry) and nitrite levels (Griess reaction). T and l -arginine treatment were accompanied by resting bradycardia, augmented parasympathetic and reduced sympathetic activity to heart and vessels (power spectral analysis) and increased baroreflex sensitivity ( † P  < 0.05). In contrast, PVN nNOS inhibition blocked/attenuated these effects in addition to significantly increase in resting MAP and HR (with larger effects in T and l -arginine treated rats vs. respective controls, † P  < 0.05). T increased nNOS gene and protein expression within the ventromedial and posterior PVN nuclei ( † P  < 0.05). PVN nitirite levels were also increased in T and l -arginine groups ( † P  < 0.05). Data strongly suggest that training by increasing NO availability within PVN preautonomic nuclei favors both the slow down of sympathetic and the augmentation of parasympathetic activity and facilitates baroreflex control, therefore improving autonomic regulation of the heart in healthy rats. [ABSTRACT FROM AUTHOR]

Homeostasis around vascular endothelium is a function of the equilibrium between the bioavailability of nitric oxide (NO) and oxidizing reactive oxygen species (ROS). Within the vascular endothelium, NO enhances vasodilatation, reduces platelet aggression and adhesion (anti-thrombotic), prevents smooth muscle proliferation, inhibits adhesion of leukocytes and expression of pro-inflammatory cytokines genes (anti-inflammatory), and counters the oxidation of low density lipoprotein (LDL) cholesterol. A shift in the equilibrium that favours NO deficiency and ROS formation leads to endothelial dysfunction and cardiovascular disease. The synthesis of NO is catalysed by nitric oxide synthase and co-factored by tetrahydrobiopterin (BH4), nicotinamide-adenine-dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), and flavin mononucleotide (FMN). The focus of this review is on endothelial nitric oxide synthase (eNOS), although we recognize that the other nitric oxide synthases may contribute as well. Levels of homocysteine and the active metabolite of folate, 5-methyltetrahydrofolate (5-MTHF), play a determining role in circulating levels of nitric oxide. We review endothelial nitric oxide bioavailabilty in relation to endothelial dysfunction as well as the therapeutic strategies involving the nitric oxide synthesis pathway. Although folate supplementation improves endothelial function, results from large clinical trials and meta-analyses on palpable clinical endpoints have been inconsistent. There are however, encouraging results from animal and clinical studies of supplementation with the co-factor for nitric oxide synthesis, BH4, though its tendency to be oxidized to dihydrobiopterin (BH2) remains problematic. Understanding how to maintain a high ratio of BH4 to BH2 appears to be the key that will likely unlock the therapeutic potential of nitric oxide synthesis pathway. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular diseases represent a hallmark characteristic in COPD, and endothelial dysfunction has been observed in these patients. Tetrahydrobiopterin (BH4) is an essential cofactor for nitric oxide (NO) synthesis and a regulator of endothelial function. The goal of this study was to test the hypothesis that a single dose of BH4 would improve endothelial function in patients with COPD via an increase in NO bioavailability.Methods: Seventeen patients with COPD completed a randomized, double-blind, placebo (PLC)-controlled, crossover trial with an acute dose of either BH4 (Kuvan; BioMarin Pharmaceutical Inc) or PLC. Flow-mediated dilation (FMD), a bioassay of endothelial function, was completed prior to and 3 h following each treatment. Phospho- and total endothelial NO synthase (NOS3) protein was evaluated after incubating endothelial cells with plasma from the patients prior to and following treatment. Fifteen demographically matched control subjects were tested at baseline for case control comparisons.Results: Treatment with BH4 significantly (P ≤ .004) increased FMD, improving endothelial function in patients compared to control values (P ≥ .327). BH4 increased (P = .013) the ratio of phospho-NOS3 to total NOS3 protein. No changes in FMD (P ≥ .776) or the protein ratio (P = .536) were observed following PLC.Conclusions: An acute dose of BH4 was able to improve endothelial function in patients with COPD to values similar to control subjects. The improvement in endothelial function was accompanied by an increase in NOS3 phosphorylation. BH4 may represent a potential novel therapy to improve endothelial function and reduce cardiovascular disease risk in patients with COPD.Trial Registry: ClinicalTrials.gov; No.: NCT01398943; URL: www.clinicaltrials.gov. [ABSTRACT FROM AUTHOR]

The main purpose of this work was to evaluate the effects of jugular l-arginine infusion on antioxidant mechanisms in lactating dairy cows challenged intravenously with lipopolysaccharide (LPS). Eight multiparous Holstein cows (609 ± 32 kg) at midlactation were randomly assigned to 5-d jugular infusions of Control (saline), Arginine (Arg, 18 g/d), LPS (0.2 µg/kg BW per day), and LPS + Arginine (0.2 µg/kg BW per day of LPS and 18 g/d of Arg) in a replicated 4 × 4 Latin square design with 4 infusion periods separated by 10-d. Jugular solutions of saline, Arg, LPS, and LPS + Arg were continuously infused using peristaltic pumps for approximately 6 h/d. Jugular vein serum samples were obtained on the last day of each infusion period before infusion (0 h) and at 3- and 6-h postinfusion. Compared with LPS treatment, Arg infusion increased the total antioxidant capacity and activity of glutathione peroxidase, but decreased malondialdehyde concentration (P < 0.05). The concentration of nitric oxide in serum and the activity of nitric oxide synthase were greater in LPS treatment compared with saline and Arg (P < 0.05). The Arg treatment significantly increased the serum insulin concentration at 3-h postinfusion compared with the saline treatment (P < 0.05), and that of LPS and LPS + Arg treatments were in between Arg and LPS treatments. No treatment effect was observed on the activities of superoxide dismutase and catalase (P > 0.05). In conclusion, enhancing the supply of Arg during an inflammatory challenge enhances antioxidant mechanisms in lactating dairy cows. [ABSTRACT FROM AUTHOR]

Summary: This study reports the synthesis, molecular docking and biological evaluation of eight (5‐8 and 5a‐8a) newly synthesized thieno‐pyrimidinone methanesulphonamide thio‐derivatives. The synthetic route used to prepare the new isomers thioaryl and thio‐cycloesyl derivatives of the heterocyclic system 6‐phenylthieno[3,2]pyrimidinone was economically and environmentally very advantageous and characterized by the simplicity of procedure, reduction in isolation steps, purification phases, time, costs and waste production. The study in silico for the evaluation of cyclooxygenase (COX)‐1 and COX‐2 selective inhibition was carried out by AutoDock Vina, an open‐source program for doing molecular docking which predicts the preferred orientation of one molecule to a second when bound to each other to form a stable complex. The research in vitro for the biological evaluation was performed by using human cartilage and chondrocytes cultures treated with 10 ng/mL of interleukin‐1beta as inflammation models. The anti‐inflammatory activity of each new compound at the concentration of 10 μmol/L was determined by assaying COX‐2, inducible nitric oxide synthetase (iNOS) and intercellular adhesion molecule 1 (ICAM 1) through Western blot. The examined derivatives showed interesting pharmacological activity, and the compound N‐[2‐[2,4‐difluorophenyl)thio]‐4‐oxo‐6‐phenylthieno[3,2‐d]pyridine‐34H‐yl]methanesulphonamide (7) was excellent COX‐2 inhibitor. In agreement with the biological data, compound 7 was able to fit into the active site of COX‐2 with highest interaction energy. These results can support the design of novel specific inhibitors of COX‐2 by the comparative modelling of COX‐1 and COX‐2 enzymes with the available pharmacophore. [ABSTRACT FROM AUTHOR]

Marfan syndrome (MS) is of the most common connective tissue disorders. Although most patients have mutations in the fibrillin-1 gene (FBN1) and more than 1,700 mutations have been described, there are no mutations in less than 10% of patients. Aortic dilation is the most important complication; it involves chronic inflammatory processes and endothelial dysfunction. Prospective study from March 2015 to January 2017, in a cohort of 32 patients of MS confirmed by Ghent criteria and 35 controls of both genders, with a median age of 26 years (18–56). Patients had no comorbidities such as diabetes, hypertension, and/or neoplasms. They were not being treated with statin, NSAIDs, calcium antagonists, oral nitrates, and/or beta-blockers during 7 days prior to the study and patients with smoking history in the last 4 years. Controls were matched by age and gender. We analyzed endothelial dysfunction by flow-mediated vasodilation in the brachial artery, determining the maximum peak flow in the reactive hyperemia phase with a Philips Envisor device with Doppler capability. Its correlation with serum levels of biological markers that could participate in endothelial dysfunction pathways such as NO 3 − / NO 2 − ratio, NO 2 − , citrulline, TNFα, IL-1, IL-6, IL-10, IL-8, osteopontin, ICAM, VCAM, and NO 3 − / NO 2 − was determined. Endothelial dysfunction was found in 21 MS patients (65%). The aortic annulus (AAo) was of 27 mm (22–40) and 24 mm (22–30) (p = 0.04) in MS patients with and without dysfunction. The level of NO 3 − / NO 2 − ratio, was of 108.95 ± 12.05 nM/ml in controls vs. 170.04 ± 18.76 nM/ml in MS (p = 0.002), NO 2 − was of 33.78 ± 3.41 vs. 43.95 ± 2.59 nM/ml (p = 0.03), citrulline 62.65 ± 3.46 vs. 72.81 ± 4.35 μMol/ml (p = 0.06). VCAM median was 39 pg/ml (0–86) vs. 32 pg/ml (11–66) (p = 0.03), respectively. The correlation of VCAM with triglycerides (TG) was of 0.62 (p = 0.005). There were no differences in TNFα, IL-1, IL-6, IL-8, IL-10, and osteopontin. MS endothelial dysfunction is related to aortic diameters, and increased levels of VCAM, L-citrulline and NO 3 − / NO 2 − ratio, NO 2 − . VCAM-1 has a significant correlation with TG and could play a significant role in endothelial dysfunction. [ABSTRACT FROM AUTHOR]

Purpose: We investigated the influence of inorganic nitrate ([Formula: see text]) supplementation on local sweating and cutaneous vascular responses during exercise in hot conditions.Method: Eight healthy, young subjects were assigned in a randomized, double-blind, crossover design to receive [Formula: see text]-rich beetroot (BR) juice (140 mL/day, containing ~ 8 mmol of [Formula: see text]) and [Formula: see text]-depleted placebo (PL) juice (140 mL/day, containing ~ 0.003 mmol of [Formula: see text]) for 3 days. On day 3 of supplementation, subjects cycled at an intensity corresponding to 55% of [Formula: see text]O2max for 30 min in hot conditions (30 °C, 50% relative humidity). Chest and forearm sweat rate (SR) and skin blood flow (SkBF), were measured continuously. Cutaneous vascular conductance (CVC) was calculated by SkBF/mean arterial pressure (MAP).Results: Prior to exercise, plasma [Formula: see text] (21 ± 6 and 581 ± 161 µM) and nitrite ([Formula: see text], 87 ± 28 and 336 ± 156 nM) concentrations were higher after BR compared to PL supplementation (P ≤ 0.011, n = 6). Oesophageal, mean skin, and mean body temperatures during exercise were not different between conditions. In addition, BR supplementation did not affect SR, SkBF, and CVC during exercise. A lower MAP was found after 30 min of exercise following BR supplementation (112 ± 6 and 103 ± 6 mmHg for PL and BR, respectively, P = 0.021).Conclusion: These results suggest that inorganic [Formula: see text] supplementation, which increases the potential for O2-independent NO production, does not affect local sweating and cutaneous vascular responses, but attenuates blood pressure in young healthy subjects exercising in a hot environment. [ABSTRACT FROM AUTHOR]

CD4+ T cells can induce potent anti-tumor immune responses. Due to the lack of MHC class II expression in most cancer cells, antigen recognition occurs indirectly via uptake and presentation on tumor-infiltrating antigen-presenting cells (APCs). Activation of the APCs can induce tumor rejection, but the mechanisms underlying tumor killing by such cells have not been established. To elucidate the molecular basis of CD4+ T-cell-mediated tumor rejection, we utilized a murine model of multiple myeloma, in which the T cells recognize a secreted tumor neoantigen. Our findings demonstrate that T cell recognition triggers inducible nitric oxide synthase activity within tumor-infiltrating macrophages. Diffusion of nitric oxide into surrounding tumor cells results in intracellular accumulation of toxic secondary oxidants, notably peroxynitrite. This results in tumor cell apoptosis through activation of the mitochondrial pathway. We find that this mode of cytotoxicity has strict spatial limitations, and is restricted to the immediate surroundings of the activated macrophage, thus limiting bystander killing. These findings provide a molecular basis for macrophage-mediated anti-tumor immune responses orchestrated by CD4+ T cells. Since macrophages are abundant in most solid tumors, evoking the secretion of nitric oxide by such cells may represent a potent therapeutic strategy. [ABSTRACT FROM AUTHOR]