Exposure to aircraft noise exacerbates cardiovascular and oxidative damage in three mouse models of diabetes

Short-term aircraft noise stress induces a fundamental metabolic shift in heart proteome and metabolome that bears the hallmarks of cardiovascular disease

Environmental stressors in the modern world can fundamentally affect human physiology and health. Exposure to stressors like air pollution, heat, and traffic noise has been linked to a pronounced increase in non-communicable diseases. Specifically, aircraft noise has been identified as a risk factor for cardiovascular and metabolic diseases, such as arteriosclerosis, heart failure, stroke, and diabetes. Noise stress leads to neuronal activation with subsequent stress hormone release that ultimately activates the renin-angiotensin-aldosterone system, increases inflammation and oxidative stress thus substantially affecting the cardiovascular system. However, despite the epidemiological evidence of a link between noise stress and metabolic dysfunction, the consequences of exposure at the molecular, metabolic level of the cardiovascular system are largely unknown. Here, we use a murine model system of short-term aircraft noise exposure to show that noise stress profoundly alters heart metabolism. Within 4 days of noise exposure, the heart proteome and metabolome bear the hallmarks of reduced potential for generating ATP from fatty-acid beta-oxidation, the tricarboxylic acid cycle, and the electron transport chain. This is accompanied by the increased expression of glycolytic metabolites, including the end-product, lactate, suggesting a compensatory shift of energy production towards anaerobic glycolysis. Intriguingly, the metabolic shift is reminiscent of what is observed in failing and ischaemic hearts. Mechanistically, we further show that the metabolic rewiring is likely driven by reactive oxygen species (ROS), as we can rescue the phenotype by knocking out NOX-2/gp91phox, a ROS inducer, in mice. Our results suggest that within a short exposure time, the cardiovascular system undergoes a fundamental metabolic shift that bears the hallmarks of cardiovascular disease. These findings underscore the urgent need to comprehend the molecular consequences of environmental stressors, paving the way for targeted interventions to mitigate health risks associated with chronic noise exposure in modern, environments heavily disturbed by noise pollution.

CD40-TRAF6 inhibition suppresses cardiovascular inflammation, oxidative stress and functional complications in a mouse model of arterial hypertension

Cardiovascular disease is the leading cause of disease burden and death worldwide and is fueled by vascular inflammation. CD40L-CD40-TRAF signaling is involved in the progression of atherosclerosis and drives the development of coronary heart disease (CHD). The present study investigates whether the CD40L-CD40-TRAF6 signaling pathway with focus on immune cells and adipocytes could be a therapeutic target in arterial hypertension. Arterial hypertension was induced in WT (C57BL6/J) and cell-specific CD40(L) knockout mice (AdipoqCre x CD40 fl/fl, CD4Cre x CD40 fl/fl, CD19Cre x CD40 fl/fl, and GP1baCre x CD40L fl/fl) via angiotensin (AT-II) infusion (1 mg/kg/d) for seven days. Hypertensive WT mice were also treated with a CD40-TRAF6 inhibitor (2.5 mg/kg/d, for 7d). The TRAF6 inhibitor treatment normalized endothelial dysfunction and reduced blood pressure in hypertensive wild type animals. Reactive oxygen species production was decreased by TRAF6 inhibition in blood, aorta, heart, kidney, and perivascular fat tissue. Additionally, FACS analysis revealed that TRAF6 inhibition prevents immune cell migration into the aortic vessel wall observed by reduced CD45+ leukocyte, Ly6G+/Ly6C+ neutrophil, and Ly6Chigh inflammatory monocyte content. The hypertensive cell type-specific CD40(L) knockout animals showed only a minor effect on endothelial function, blood pressure, and oxidative stress. Therefore, we conclude that targeting CD40 directly on adipocytes, B-cells, T-cells, or CD40L on platelets is not a promising target to prevent hypertension complications. In summary, TRAF6 inhibition but not adipocyte, B-cell, or T-cell-specific CD40 or platelet-specific CD40L deficiency reduces pathophysiological vascular inflammation in hypertensive mice, suggesting TRAF6 inhibition as a potential therapeutic target in hypertensive patients.

Residential exposome and the risk of coronary obstruction and myocardial ischemia detected by coronary computed tomography

BACKGROUND AND AIMS

To assess independent impacts of air and noise pollution, and residential green exposure on non-invasively derived coronary obstruction and myocardial ischemia.

METHODS

Consecutive patients screened by coronary computed tomography angiography (CCTA) for stable chest pain between 01/01/2019 and 31/12/2020 were included in a registry. Exposure associations between residential PM2.5 (particulate matter <2.5 micrometres), NO2 (nitric dioxide), major road distance, airport distance and normalized difference vegetation index (NDVI), and obstructive coronary artery disease (OCAD, stenosis ≥50%) and abnormal fractional flow reserve (FFRCT<80%) measurement were assessed by propensity score-adjusted logistic regression. Subgroup analysis was performed according to Framingham low (<10%) and high (>20%) 10-year coronary heart disease risk categories.

RESULTS

2620 patients were enrolled, including 420(16%) FFRCT analyses. OCAD was reported in 518(20%) patients and abnormal FFRCT in 276(11%). People with OCAD lived closer to the airport (10.841 [7.869-19.022]km vs. 12.297 [8.691-22.843]km, p<0.001). People living closer to the airport had more cardiovascular and socio-economic risk factors. Distance to airport decreased OCAD risk (OR 0.983, 95%CI 0.974-0.992, per 1km) in univariable analysis. After propensity score (PS) adjustment, environmental stressors were not significantly associated with OCAD, regardless of risk categories. Only distance to major road decreased abnormal FFRCT risk (OR 0.634, 95%CI: 0.421-0.926, per 1km) in high-risk patients after PS adjustment.

CONCLUSIONS

We found no clear environmental associations with CT-derived coronary obstruction or ischemia. However, airport proximity was linked to OCAD risk via cardiovascular and socio-economic factors, while major road proximity was independently associated with myocardial ischemia in high-CV-risk patients, warranting further investigation.

Interventions by Cardiovascular Drugs Against Aircraft Noise-Induced Cardiovascular Oxidative Stress and Damage

Noise pollution is a known health risk factor and evidence for cardiovascular diseases associated with traffic noise is growing. At least 20% of the European Union's population lives in noise-polluted areas with exposure levels exceeding the recommended limits of the World Health Organization, which is considered unhealthy by the European Environment Agency. This results in the annual loss of 1.6 million healthy life years. Here, we investigated the protective effects of cardiovascular drug interventions against aircraft noise-mediated cardiovascular complications such as elevated oxidative stress or endothelial dysfunction. Using our established mouse exposure model, we applied mean sound pressure levels of 72 dB(A) for 4 d. C57BL/6 mice were treated with the beta-blocker propranolol (15 mg/kg/d s.c. for 5 d) or the alpha-blocker phenoxybenzamine (1.5 mg/kg/d s.c. for 5 d) and noise-exposed for the last 4 d of the drug administration. Short-term noise exposure caused hypertension (measured by tail-cuff blood pressure monitoring) and impaired endothelial function (measured by isometric tension recording in the aorta and video microscopy in cerebral arterioles in response to acetylcholine). Noise also increased markers of oxidative stress and inflammation. Treatment of mice with propranolol and phenoxybenzamine prevented endothelial and microvascular dysfunction, which was supported by a decrease in markers of inflammation and oxidative stress in heart tissue and the brain. Amelioration of noise-induced hypertension (systolic blood pressure) was not observed, whereas pulse pressure was lowered by trend. This study provides a novel perspective mitigating the adverse effects of noise pollution, especially in vulnerable groups with medication, a rationale for further pharmacological human studies.