NECAB2 is an endosomal protein important for striatal function.

Synaptic signaling depends on ATP generated by mitochondria. Dysfunctional mitochondria shift the redox balance towards a more oxidative environment. Due to extensive connectivity, the striatum is especially vulnerable to mitochondrial dysfunction. We found that neuronal calcium-binding protein 2 (NECAB2) plays a role in striatal function and mitochondrial homeostasis. NECAB2 is a predominantly endosomal striatal protein which partially colocalizes with mitochondria. This colocalization is enhanced by mild oxidative stress. Global knockout of Necab2 in the mouse results in increased superoxide levels, increased DNA oxidation and reduced levels of the antioxidant glutathione which correlates with an altered mitochondrial shape and function. Striatal mitochondria from Necab2 knockout mice are more abundant and smaller and characterized by a reduced spare capacity suggestive of intrinsic uncoupling respectively mitochondrial dysfunction. In line with this, we also found an altered stress-induced interaction of endosomes with mitochondria in Necab2 knockout striatal cultures. The predominance of dysfunctional mitochondria and the pro-oxidative redox milieu correlates with a loss of striatal synapses and behavioral changes characteristic of striatal dysfunction like reduced motivation and altered sensory gating. Together this suggests an involvement of NECAB2 in an endosomal pathway of mitochondrial stress response important for striatal function.

The role of acrolein for E-cigarette vapour condensate mediated activation of NADPH oxidase in cultured endothelial cells and macrophages.

Electronic cigarettes (E-cigarettes) have recently become a popular alternative to traditional tobacco cigarettes. Despite being marketed as a healthier alternative, increasing evidence shows that E-cigarette vapour could cause adverse health effects. It has been postulated that degradation products of E-cigarette liquid, mainly reactive aldehydes, are responsible for those effects. Previously, we have demonstrated that E-cigarette vapour exposure causes oxidative stress, inflammation, apoptosis, endothelial dysfunction and hypertension by activating NADPH oxidase in a mouse model. To better understand oxidative stress mechanisms, we have exposed cultured endothelial cells and macrophages to condensed E-cigarette vapour (E-cigarette condensate) and acrolein. In both endothelial cells (EA.hy 926) and macrophages (RAW 264.7), we have observed that E-cigarette condensate incubation causes cell death. Since recent studies have shown that among toxic aldehydes found in E-cigarette vapour, acrolein plays a prominent role, we have incubated the same cell lines with increasing concentrations of acrolein. Upon incubation with acrolein, a translocation of Rac1 to the plasma membrane has been observed, accompanied by an increase in oxidative stress. Whereas reactive oxygen species (ROS) formation by acrolein in cultured endothelial cells was mainly intracellular, the release of ROS in cultured macrophages was both intra- and extracellular. Our data also demonstrate that acrolein activates the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway and, in general, could mediate E-cigarette vapour-induced oxidative stress and cell death. More mechanistic insight is needed to clarify the toxicity associated with E-cigarette consumption and the possible adverse effects on human health.

Mitigation of aircraft noise-induced vascular dysfunction and oxidative stress by exercise, fasting, and pharmacological α1AMPK activation: molecular proof of a protective key role of endothelial α1AMPK against environmental noise exposure.

AIMS: Environmental stressors such as traffic noise represent a global threat, accounting for 1.6 million healthy life years lost annually in Western Europe. Therefore, the noise-associated health side effects must be effectively prevented or mitigated. Non-pharmacological interventions such as physical activity or a balanced healthy diet are effective due to the activation of the adenosine monophosphate-activated protein kinase (α1AMPK). Here, we investigated for the first time in a murine model of aircraft noise-induced vascular dysfunction the potential protective role of α1AMPK activated via exercise, intermittent fasting, and pharmacological treatment. METHODS AND RESULTS: Wild-type (B6.Cg-Tg(Cdh5-cre)7Mlia/J) mice were exposed to aircraft noise [maximum sound pressure level of 85 dB(A), average sound pressure level of 72 dB(A)] for the last 4 days. The α1AMPK was stimulated by different protocols, including 5-aminoimidazole-4-carboxamide riboside application, voluntary exercise, and intermittent fasting. Four days of aircraft noise exposure produced significant endothelial dysfunction in wild-type mice aorta, mesenteric arteries, and retinal arterioles. This was associated with increased vascular oxidative stress and asymmetric dimethylarginine formation. The α1AMPK activation with all three approaches prevented endothelial dysfunction and vascular oxidative stress development, which was supported by RNA sequencing data. Endothelium-specific α1AMPK knockout markedly aggravated noise-induced vascular damage and caused a loss of mitigation effects by exercise or intermittent fasting. CONCLUSION: Our results demonstrate that endothelial-specific α1AMPK activation by pharmacological stimulation, exercise, and intermittent fasting effectively mitigates noise-induced cardiovascular damage. Future population-based studies need to clinically prove the concept of exercise/fasting-mediated mitigation of transportation noise-associated disease.

Traffic noise, e.g. from aircraft, significantly contributes to an increased risk of cardiovascular or metabolic diseases in the general population by brain-dependent stress reactions leading to higher levels of circulating stress hormones and vasoconstrictors, all of which cause hypertension, oxidative stress, and inflammation. With the present experimental studies, we provide for the first time molecular mechanisms responsible for successful noise mitigation: Physical exercise, intermittent fasting, and pharmacological activation of the adenosine monophosphate-activated protein kinase (AMPK), a metabolic master regulator protein, prevent cardiovascular damage caused by noise exposure, such as hypertension, endothelial dysfunction, and reactive oxygen species formation (e.g. free radicals) and inflammation.These beneficial mitigation manoeuvers are secondary to an activation of the endothelial AMPK, thereby mimicking the antidiabetic drug metformin.

[Cefiderocol in AML patient with neutropenic infection due to 4MRGN Klebsiella pneumoniae (VIM-1)]. / Cefiderocol bei AML-Patientin mit neutropenischem Infekt durch 4MRGN Klebsiella pneumoniae (VIM-1).

ANAMNESIS: The 68-year-old patient presented with fever, general malaise and physical weakness in neutropenia during a known relapse of acute myeloid leukaemia after allogeneic stem cell transplantation. TREATMENT/DIAGNOSIS: Due to immune suppression, an empiric antibiotic therapy with piperacillin/tazobactam was started. The 4MRGN screening was positive. For this reason, therapy was switched empirically to ceftazidime/avibactam plus colistin. A tongue ulcer with abscess formation and phlegmonous soft tissue reaction was revealed as the focus of the infection. Several microbiological probes including a blood culture discovered Klebsiella pneumoniae complex - 4MRGN that expressed a metallo-beta-lactamase of the VIM-1 type (Verona integron metallo betalactamase-1). A permanent improvement of the clinical symptoms and regredience of the infection parameters could only be achieved after antibiotic treatment was switched to the recently approved siderophor cephalosporin cefiderocol. After 18 days the antibiotic treatment could be completed successfully. The patient was discharged in a stable condition. CONCLUSION: 4MRGN pathogens are Gram-negative rod-shaped bacteria that are resistant against four main bactericidal antibiotic groups (Acylureidopenicillins, 3rd generation cephalosporins, carbapenems, and fluoroquinolones) and thus difficult to treat. The present case demonstrates good clinical efficacy for cefiderocol even in pathogens resistant to antibiotics such as colistin and ceftazidime/avibactam and highlights the importance of antibiogram-tailored therapy.

Co-exposure to urban particulate matter and aircraft noise adversely impacts the cerebro-pulmonary-cardiovascular axis in mice.

Worldwide, up to 8.8 million excess deaths/year have been attributed to air pollution, mainly due to the exposure to fine particulate matter (PM). Traffic-related noise is an additional contributor to global mortality and morbidity. Both health risk factors substantially contribute to cardiovascular, metabolic and neuropsychiatric sequelae. Studies on the combined exposure are rare and urgently needed because of frequent co-occurrence of both risk factors in urban and industrial settings. To study the synergistic effects of PM and noise, we used an exposure system equipped with aerosol generator and loud-speakers, where C57BL/6 mice were acutely exposed for 3d to either ambient PM (NIST particles) and/or noise (aircraft landing and take-off events). The combination of both stressors caused endothelial dysfunction, increased blood pressure, oxidative stress and inflammation. An additive impairment of endothelial function was observed in isolated aortic rings and even more pronounced in cerebral and retinal arterioles. The increase in oxidative stress and inflammation markers together with RNA sequencing data indicate that noise particularly affects the brain and PM the lungs. The combination of both stressors has additive adverse effects on the cardiovascular system that are based on PM-induced systemic inflammation and noise-triggered stress hormone signaling. We demonstrate an additive upregulation of ACE-2 in the lung, suggesting that there may be an increased vulnerability to COVID-19 infection. The data warrant further mechanistic studies to characterize the propagation of primary target tissue damage (lung, brain) to remote organs such as aorta and heart by combined noise and PM exposure.

Mechanistic Insights into Inorganic Nitrite-Mediated Vasodilation of Isolated Aortic Rings under Oxidative/Hypertensive Conditions and S-Nitros(yl)ation of Proteins in Germ-Free Mice.

The prevalence and clinical importance of arterial hypertension are still growing. Inorganic nitrite (NO2-) represents an attractive dietary antihypertensive agent, but its metabolism and mode of action, which we aimed to investigate with the present study, are not completely understood. Isolated aortic rings from rats were treated ex vivo with oxidants, and rats were infused in vivo with angiotensin-II. Vascular responses to acetylcholine (ACh) and nitrite were assessed by isometric tension recording. The loss of vasodilatory potency in response to oxidants was much more pronounced for ACh as compared to nitrite ex vivo (but not in vivo with angiotensin-II). This effect may be caused by the redox regulation of conversion to xanthine oxidase (XO). Conventionally raised and germ-free mice were treated with nitrite by gavage, which did not improve ACh-mediated vasodilation, but did increase the plasma levels of S-nitros(yl)ated proteins in the conventionally-raised, but not in the germ-free mice. In conclusion, inorganic nitrite represents a dietary drug option to treat arterial hypertension in addition to already established pharmacological treatment. Short-term oxidative stress did not impair the vasodilatory properties of nitrite, which may be beneficial in cardiovascular disease patients. The gastrointestinal microbiome appears to play a key role in nitrite metabolism and bioactivation.

Lack of Endothelial α1AMPK Reverses the Vascular Protective Effects of Exercise by Causing eNOS Uncoupling.

Voluntary exercise training is an effective way to prevent cardiovascular disease, since it results in increased NO bioavailability and decreased reactive oxygen species (ROS) production. AMP-activated protein kinase (AMPK), especially its α1AMPK subunit, modulates ROS-dependent vascular homeostasis. Since endothelial cells play an important role in exercise-induced changes of vascular signaling, we examined the consequences of endothelial-specific α1AMPK deletion during voluntary exercise training. We generated a mouse strain with specific deletion of α1AMPK in endothelial cells (α1AMPKflox/flox x TekCre+). While voluntary exercise training improved endothelial function in wild-type mice, it had deleterious effects in mice lacking endothelial α1AMPK indicated by elevated reactive oxygen species production (measured by dihydroethidum fluorescence and 3-nitrotyrosine staining), eNOS uncoupling and endothelial dysfunction. Importantly, the expression of the phagocytic NADPH oxidase isoform (NOX-2) was down-regulated by exercise in control mice, whereas it was up-regulated in exercising α1AMPKflox/flox x TekCre+ animals. In addition, nitric oxide bioavailability was decreased and the antioxidant/protective nuclear factor erythroid 2-related factor 2 (Nrf-2) response via heme oxygenase 1 and uncoupling protein-2 (UCP-2) was impaired in exercising α1AMPKflox/flox x TekCre+ mice. Our results demonstrate that endothelial α1AMPK is a critical component of the signaling events that enable vascular protection in response to exercise. Moreover, they identify endothelial α1AMPK as a master switch that determines whether the effects of exercise on the vasculature are protective or detrimental.

Comparison of three methods for in vivo quantification of glutathione in tissues of hypertensive rats.

Glutathione (γ-L-glutamyl-L-cysteinyl-glycine, GSH) is a tripeptide that is part of the antioxidant defense system and contributes to numerous redox-regulatory processes. In vivo, reduced GSH and oxidized glutathione disulfide (GSSG) are present in redox equilibrium and their ratio provides important information on the cellular redox state. Here, we compared three different methods for in vivo quantification of glutathione in tissues of hypertensive rats, an accepted animal model of oxidative stress. In the present study, we used hypertensive rats (infusion of 1 mg/kg/d angiotensin-II for 7 days) to determine the levels of reduced GSH and/or GSH/GSSG ratios in different tissue samples. We used an HPLC-based method with direct electrochemical detection (HPLC/ECD) and compared it with Ellman's reagent (DTNB) dependent derivatization of reduced GSH to the GS-NTB adduct and free NTB (UV/Vis HPLC) as well as with a commercial GSH/GSSG assay (Oxiselect). Whereas all three methods indicated overall a decreased redox state in hypertensive rats, the assays based on HPLC/ECD and DTNB derivatization provided the most significant differences. We applied a direct, fast and sensitive method for electrochemical GSH detection in tissues from hypertensive animals, and confirmed its reliability for in vivo measurements by head-to-head comparison with two other established assays. The HPLC/ECD but not DTNB and Oxiselect assays yielded quantitative GSH data but all three assays reflected nicely the qualitative redox changes and functional impairment in hypertensive rats. However, especially our GSH/GSSG values are lower than reported by others pointing to problems in the work-up protocol.

Influenza and RSV incidence during COVID-19 pandemic-an observational study from in-hospital point-of-care testing.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has forced the implementation of unprecedented public health measures strategies which might also have a significant impact on the spreading of other viral pathogens such as influenza and Respiratory Syncytial Virus (RSV) . The present study compares the incidences of the most relevant respiratory viruses before and during the SARS-CoV-2 pandemic in emergency room patients. We analyzed the results of in total 14,946 polymerase chain reaction point-of-care tests (POCT-PCR) for Influenza A, Influenza B, RSV and SARS-CoV-2 in an adult and a pediatric emergency room between December 1, 2018 and March 31, 2021. Despite a fivefold increase in the number of tests performed, the positivity rate for Influenza A dropped from 19.32% (165 positives of 854 tests in 2018/19), 14.57% (149 positives of 1023 in 2019-20) to 0% (0 positives of 4915 tests) in 2020/21. In analogy, the positivity rate for Influenza B and RSV dropped from 0.35 to 1.47%, respectively, 10.65-21.08% to 0% for both in 2020/21. The positivity rate for SARS-CoV2 reached 9.74% (110 of 1129 tests performed) during the so-called second wave in December 2020. Compared to the two previous years, seasonal influenza and RSV incidence was eliminated during the COVID-19 pandemic. Corona-related measures and human behavior patterns could lead to a significant decline or even complete suppression of other respiratory viruses such as influenza and RSV.

Doxorubicin induces wide-spread transcriptional changes in the myocardium of hearts distinguishing between mice with preserved and impaired cardiac function.

AIMS: Doxorubicin (DOX) is an important drug for the treatment of various tumor entities. However, the occurrence of heart failure limits its application. This study investigated differential gene expression profiles in the left and right ventricles of DOX treated mice with either preserved or impaired myocardial function. We provide new mechanistic insights into the pathophysiology of DOX-induced heart failure and have discovered pathways that counteract DOX-induced cardiotoxicity. MAIN METHODS: We used in total 48 male mice and applied a chronic low dose DOX administration (5 mg/kg per injection, in total 20 mg/kg over 4 weeks) to induce heart failure. Echocardiographic parameters were evaluated one week after the final dose and mice were separated according to functional parameters into doxorubicin responding and non-responding animals. Post mortem, measurements of reactive oxygen species (ROS) and gene expression profiling was performed in separated right and left hearts. KEY FINDINGS: We detected significant ROS production in the left heart of the mice in response to DOX treatment, although interestingly, not in the right heart. We found that transcriptional changes differ between right and left heart correlating with the occurrence of myocardial dysfunction. SIGNIFICANCE: Doxorubicin induces changes in gene expression in the entire heart of animals without necessarily impairing cardiac function. We identified a set of transcripts that are associated with DOX cardiotoxicity. These might represent promising targets to ameliorate DOX-induced heart failure. Moreover, our results emphasize that parameters of left and right heart function should be evaluated during standardized echocardiography in patients undergoing DOX therapy.

Direct comparison of inorganic nitrite and nitrate on vascular dysfunction and oxidative damage in experimental arterial hypertension.

Arterial hypertension is one of the major health risk factors leading to coronary artery disease, stroke or peripheral artery disease. Dietary uptake of inorganic nitrite (NO2-) and nitrate (NO3-) via vegetables leads to enhanced vascular NO bioavailability and provides antihypertensive effects. The present study aims to understand the underlying vasoprotective effects of nutritional NO2- and NO3- co-therapy in mice with angiotensin-II (AT-II)-induced arterial hypertension. High-dose AT-II (1 mg/kg/d, 1w, s. c.) was used to induce arterial hypertension in male C57BL/6 mice. Additional inorganic nitrite (7.5 mg/kg/d, p. o.) or nitrate (150 mg/kg/d, p. o.) were administered via the drinking water. Blood pressure (tail-cuff method) and endothelial function (isometric tension) were determined. Oxidative stress and inflammation markers were quantified in aorta, heart, kidney and blood. Co-treatment with inorganic nitrite, but not with nitrate, normalized vascular function, oxidative stress markers and inflammatory pathways in AT-II treated mice. Of note, the highly beneficial effects of nitrite on all parameters and the less pronounced protection by nitrate, as seen by improvement of some parameters, were observed despite no significant increase in plasma nitrite levels by both therapies. Methemoglobin levels tended to be higher upon nitrite/nitrate treatment. Nutritional nitric oxide precursors represent a non-pharmacological treatment option for hypertension that could be applied to the general population (e.g. by eating certain vegetables). The more beneficial effects of inorganic nitrite may rely on superior NO bioactivation and stronger blood pressure lowering effects. Future large-scale clinical studies should investigate whether hypertension and cardiovascular outcome in general can be influenced by dietary inorganic nitrite therapy.

Detection of extracellular superoxide in isolated human immune cells and in an animal model of arterial hypertension using hydropropidine probe and HPLC analysis.

Superoxide formation is a hallmark of cardiovascular disease with the involvement of different tissues and cell types. Identification of the cellular sources and subcellular localization of superoxide formation is important to understand the underlying disease pathomechanisms. In the present study, we used HPLC quantification of the superoxide-specific oxidation products of hydroethidine (HE or DHE) and its derivative hydropropidine (HPr+) for measurement of intra- and extracellular superoxide formation in isolated leukocytes and tissues of hypertensive rats. Superoxide generation by isolated leukocytes from human subjects as well as tissue samples of hypertensive rats (infusion of angiotensin-II for 7 days) was investigated using HPr+ and HE fluorescent probes with HPLC or plate reader detection. Both fluorescent dyes were used to test for intra- and extracellular superoxide formation using the supernatant or cell/tissue pellet for analysis. We demonstrate the correlation of impaired functional parameters (blood pressure, vascular function, and oxidative burst) and increased superoxide formation in different organ systems of hypertensive rats using the HPr+/HPLC method. In the cell model, the differences between HE and HPr+ and especially the advantage of the extracellular specificity of HPr+, due to its cell impermeability, became evident. Plate reader-based assays showed much higher background signal and were inferior to HPLC based methods. In conclusion, the HPr+/HPLC assay for superoxide determination is highly reliable in isolated immune cells and an animal model of arterial hypertension. In particular, the cell impermeability of HPr+ made it possible to differentiate between intra- and extracellular superoxide formation.

Noise-Induced Vascular Dysfunction, Oxidative Stress, and Inflammation Are Improved by Pharmacological Modulation of the NRF2/HO-1 Axis.

Vascular oxidative stress, inflammation, and subsequent endothelial dysfunction are consequences of traditional cardiovascular risk factors, all of which contribute to cardiovascular disease. Environmental stressors, such as traffic noise and air pollution, may also facilitate the development and progression of cardiovascular and metabolic diseases. In our previous studies, we investigated the influence of aircraft noise exposure on molecular mechanisms, identifying oxidative stress and inflammation as central players in mediating vascular function. The present study investigates the role of heme oxygenase-1 (HO-1) as an antioxidant response preventing vascular consequences following exposure to aircraft noise. C57BL/6J mice were treated with the HO-1 inducer hemin (25 mg/kg i.p.) or the NRF2 activator dimethyl fumarate (DMF, 20 mg/kg p.o.). During therapy, the animals were exposed to noise at a maximum sound pressure level of 85 dB(A) and a mean sound pressure level of 72 dB(A). Our data showed a marked protective effect of both treatments on animals exposed to noise for 4 days by normalization of arterial hypertension and vascular dysfunction in the noise-exposed groups. We observed a partial normalization of noise-triggered oxidative stress and inflammation by hemin and DMF therapy, which was associated with HO-1 induction. The present study identifies possible new targets for the mitigation of the adverse health effects caused by environmental noise exposure. Since natural dietary constituents can achieve HO-1 and NRF2 induction, these pathways represent promising targets for preventive measures.

Long-Term Effects of Aircraft Noise Exposure on Vascular Oxidative Stress, Endothelial Function and Blood Pressure: No Evidence for Adaptation or Tolerance Development.

Transportation noise is recognized as an important cardiovascular risk factor. Key mechanisms are noise-triggered vascular inflammation and oxidative stress with subsequent endothelial dysfunction. Here, we test for adaptation or tolerance mechanisms in mice in response to chronic noise exposure. C57BL/6J mice were exposed to aircraft noise for 0, 4, 7, 14 and 28d at a mean sound pressure level of 72 dB(A) and peak levels of 85 dB(A). Chronic aircraft noise exposure up to 28d caused persistent endothelial dysfunction and elevation of blood pressure. Likewise, reactive oxygen species (ROS) formation as determined by dihydroethidium (DHE) staining and HPLC-based measurement of superoxide formation in the aorta/heart/brain was time-dependently increased by noise. Oxidative burst in the whole blood showed a maximum at 4d or 7d of noise exposure. Increased superoxide formation in the brain was mirrored by a downregulation of neuronal nitric oxide synthase (Nos3) and transcription factor Foxo3 genes, whereas Vcam1 mRNA, a marker for inflammation was upregulated in all noise exposure groups. Induction of a pronounced hearing loss in the mice was excluded by auditory brainstem response audiometry. Endothelial dysfunction and inflammation were present during the entire 28d of aircraft noise exposure. ROS formation gradually increases with ongoing exposure without significant adaptation or tolerance in mice in response to chronic noise stress at moderate levels. These data further illustrate health side effects of long-term noise exposure and further strengthen a consequent implementation of the WHO noise guidelines in order to prevent the development of noise-related future cardiovascular disease.

The AMP-Activated Protein Kinase Plays a Role in Antioxidant Defense and Regulation of Vascular Inflammation.

Cardiovascular diseases represent the leading cause of global deaths and life years spent with a severe disability. Endothelial dysfunction and vascular oxidative stress are early precursors of atherosclerotic processes in the vascular wall, all of which are hallmarks in the development of cardiovascular diseases and predictors of future cardiovascular events. There is growing evidence that inflammatory processes represent a major trigger for endothelial dysfunction, vascular oxidative stress and atherosclerosis and clinical data identified inflammation as a cardiovascular risk factor on its own. AMP-activated protein kinase (AMPK) is a central enzyme of cellular energy balance and metabolism that has been shown to confer cardio-protection and antioxidant defense which thereby contributes to vascular health. Interestingly, AMPK is also redox-regulated itself. We have previously shown that AMPK largely contributes to a healthy endothelium, confers potent antioxidant effects and prevents arterial hypertension. Recently, we provided deep mechanistic insights into the role of AMPK in cardiovascular protection and redox homeostasis by studies on arterial hypertension in endothelial and myelomonocytic cell-specific AMPK knockout (Cadh5CrexAMPKfl/fl and LysMCrexAMPKfl/fl) mice. Using these cell-specific knockout mice, we revealed the potent anti-inflammatory properties of AMPK representing the molecular basis of the antihypertensive effects of AMPK. Here, we discuss our own findings in the context of literature data with respect to the anti-inflammatory and antioxidant effects of AMPK in the specific setting of arterial hypertension as well as cardiovascular diseases in general.

Environmental aircraft noise aggravates oxidative DNA damage, granulocyte oxidative burst and nitrate resistance in Ogg1-/- mice.

Background: Large epidemiological studies point towards a link between the incidence of arterial hypertension, ischaemic heart disease, metabolic disease and exposure to traffic noise, supporting the role of noise exposure as an independent cardiovascular risk factor. We characterised the underlying molecular mechanisms leading to noise-dependent adverse effects on the vasculature and myocardium in an animal model of aircraft noise exposure and identified oxidative stress and inflammation as central players in mediating vascular and cardiac dysfunction. Here, we studied the impact of noise-induced oxidative DNA damage on vascular function in DNA-repair deficient 8-oxoguanine glycosylase knockout (Ogg1-/-) mice.Methods and results: Noise exposure (peak sound levels of 85 and mean sound level of 72 dB(A) applied for 4d) caused oxidative DNA damage (8-oxoguanine) and enhanced NOX-2 expression in C57BL/6 mice with synergistic increases in Ogg1-/- mice (shown by immunohistochemistry). A similar pattern was found for oxidative burst of blood leukocytes and other markers of oxidative stress (4-hydroxynonenal, 3-nitrotyrosine) and inflammation (cyclooxygenase-2). We observed additive impairment of noise exposure and genetic Ogg1 deficiency on endothelium-independent relaxation (nitroglycerine), which may be due to exacerbated oxidative DNA damage leading to leukocyte activation and oxidative aldehyde dehydrogenase inhibition.Conclusions: The finding that chronic noise exposure causes oxidative DNA damage in mice is worrisome since these potential mutagenic lesions could contribute to cancer progression. Human field studies have to demonstrate whether oxidative DNA damage is also found in urban populations with high levels of noise exposure as recently shown for workers with high occupational noise exposure.

Short-term e-cigarette vapour exposure causes vascular oxidative stress and dysfunction: evidence for a close connection to brain damage and a key role of the phagocytic NADPH oxidase (NOX-2).

AIMS: Electronic (e)-cigarettes have been marketed as a 'healthy' alternative to traditional combustible cigarettes and as an effective method of smoking cessation. There are, however, a paucity of data to support these claims. In fact, e-cigarettes are implicated in endothelial dysfunction and oxidative stress in the vasculature and the lungs. The mechanisms underlying these side effects remain unclear. Here, we investigated the effects of e-cigarette vapour on vascular function in smokers and experimental animals to determine the underlying mechanisms. METHODS AND RESULTS: Acute e-cigarette smoking produced a marked impairment of endothelial function in chronic smokers determined by flow-mediated dilation. In mice, e-cigarette vapour without nicotine had more detrimental effects on endothelial function, markers of oxidative stress, inflammation, and lipid peroxidation than vapour containing nicotine. These effects of e-cigarette vapour were largely absent in mice lacking phagocytic NADPH oxidase (NOX-2) or upon treatment with the endothelin receptor blocker macitentan or the FOXO3 activator bepridil. We also established that the e-cigarette product acrolein, a reactive aldehyde, recapitulated many of the NOX-2-dependent effects of e-cigarette vapour using in vitro blood vessel incubation. CONCLUSIONS: E-cigarette vapour exposure increases vascular, cerebral, and pulmonary oxidative stress via a NOX-2-dependent mechanism. Our study identifies the toxic aldehyde acrolein as a key mediator of the observed adverse vascular consequences. Thus, e-cigarettes have the potential to induce marked adverse cardiovascular, pulmonary, and cerebrovascular consequences. Since e-cigarette use is increasing, particularly amongst youth, our data suggest that aggressive steps are warranted to limit their health risks.

T Cell-Derived IL-17A Induces Vascular Dysfunction via Perivascular Fibrosis Formation and Dysregulation of ·NO/cGMP Signaling.

AIMS: The neutrophil recruiting cytokine Interleukin-17A (IL-17A) is a key component in vascular dysfunction and arterial hypertension. Moreover, IL-17A has a central role for the vascular infiltration of myeloid cells into the arterial wall in Angiotensin II-induced vascular inflammation. The intention of our study was to analyze the impact of T cell-derived IL-17A on hypertension, vascular function, and inflammation. METHODS AND RESULTS: Chronic IL-17A overexpression in T cells (CD4-IL-17Aind/+ mice) resulted in elevated reactive oxygen species in the peripheral blood and a significant vascular dysfunction compared to control mice. The vascular dysfunction seen in the CD4-IL-17Aind/+ mice was only accompanied by a modest and nonsignificant accumulation of inflammatory cells within the vessel wall. Therefore, infiltrating myeloid cells did not serve as an explanation of the vascular dysfunction seen in a chronic IL-17A-driven mouse model. In addition to vascular dysfunction, CD4-IL-17Aind/+ mice displayed vascular fibrosis with highly proliferative fibroblasts. This fibroblast proliferation was induced by exposure to IL-17A as confirmed by in vitro experiments with primary murine fibroblastic cells. We also found that the ·NO/cGMP pathway was downregulated in the vasculature of the CD4-IL-17Aind/+ mice, while levels of protein tyrosine kinase 2 (PYK2), an oxidative stress-triggered process associated with T cell activation, were upregulated in the perivascular fat tissue (PVAT). CONCLUSIONS: Our data demonstrate that T cell-derived IL-17A elicits vascular dysfunction by mediating proliferation of fibroblasts and subsequent vascular fibrosis associated with PYK2 upregulation.

Stimulatory TSH-Receptor Antibodies and Oxidative Stress in Graves Disease.

Context: We hypothesized that TSH-receptor (TSHR) stimulating antibodies (TSAbs) are involved in oxidative stress mechanisms in patients with Graves disease (GD). Methods: Nicotinamide adenine dinucleotide phosphate oxidase, isoform 2 (NOX2); oxidative parameters; and oxidative burst were measured in serum, urine, and whole blood from patients with GD and control subjects. Superoxide production was investigated in human embryonic kidney (HEK)-293 cells stably overexpressing the TSHR. Lipid peroxidation was determined by immunodot-blot analysis for protein-bound 4-hydroxy-2-nonenal (4-HNE) in human primary thyrocytes and HEK-293-TSHR cells. Results: Serum NOX2 levels were markedly higher in hyperthyroid untreated vs euthyroid treated patients with GD, hyperthyroid patients with toxic nodular goiter, and euthyroid healthy control subjects (all P < 0.0001). Urine oxidative parameters were increased in patients with GD vs patients with toxic goiter (P < 0.01) and/or control subjects (P < 0.001). The maximum of the zymosan A- and phorbol 12,13-dibutyrate-induced respiratory burst of leukocytes was 1.5-fold higher in whole blood from hyperthyroid patients with GD compared with control subjects (P < 0.001 and P < 0.05). Monoclonal M22 TSAbs stimulated cAMP (HEK cells) in a dose-dependent manner. M22 (P = 0.0082), bovine TSH (P = 0.0028), and sera of hyperthyroid patients with GD (P < 0.05) increased superoxide-specific 2-hydroxyethidium levels in HEK-293 TSHR cells after 48-hour incubation vs control subjects. In contrast, triiodothyronine (T3) did not affect reactive oxygen species (ROS) production. In primary thyrocytes, the 4-HNE marker was higher in patients with GD vs control subjects at 6 and 48 hours (P = 0.02 and P = 0.04, respectively). Further, after 48-hour incubation of HEK-293 TSHR cells with patient sera, 4-HNE was higher in patients with untreated GD compared with control subjects (P < 0.05). Conclusions: Monoclonal M22 and polyclonal serum TSAbs augment ROS generation and/or induce lipid peroxidation.

Basic in vitro Characterization of the Vasodilatory Potential of 2-Aminoethyl Nitrate Fixed-Dose Combinations with Cilostazol, Metoprolol and Valsartan.

BACKGROUND/AIMS: 2-aminoethyl nitrate (CLC-1011) is a member of the class of organic nitrates that cause vasodilation by the generation of nitric oxide (•NO). These drugs are mainly used for the treatment of angina pectoris and ischemic heart disease. The aim of this study was to characterize the vasodilatory potency of this organic nitrate alone and in combination with clinically established cardiovascular drugs. METHODS: Vasodilation by CLC-1011 was tested by isometric tension studies, either alone or combined with cilostazol, valsartan, and metoprolol. Induction of oxidative stress in isolated heart mitochondria was measured by enhanced chemiluminescence. Bioactivation of CLC-1011 in aortic tissue was measured by electron paramagnetic resonance spectroscopy using an iron-based spin trap for •NO. RESULTS: We observed potent vasodilation by CLC-1011 and additive effects for all three drug combinations. In contrast to nitroglycerin (GTN), CLC-1011 did not stimulate mitochondrial oxidative stress. CLC-1011 was bioactivated to •NO in aortic tissue. CONCLUSION: In summary, the experiments described in this report demonstrate that CLC-1011 does not induce oxidative stress, is a more potent vasodilator than isosorbide-5-mononitrate and dinitrate ISDN, and displays synergistic vasodilation with other cardiovascular drugs. CLC-1011 fixed dose combinations could be used in the management of cardiovascular diseases.