(–)-Epicatechin Alters Reactive Oxygen and Nitrogen Species Production Independent of Mitochondrial Respiration in Human Vascular Endothelial Cells

Introduction. Vascular endothelial dysfunction is characterised by lowered nitric oxide (NO) bioavailability, which may be explained by increased production of reactive oxygen species (ROS), mitochondrial dysfunction, and altered cell signalling. (-)-Epicatechin (EPI) has proven effective in the context of vascular endothelial dysfunction, but the underlying mechanisms associated with EPI’s effects remain unclear. Objective(s). Our aim was to investigate whether EPI impacts reactive oxygen and nitrogen species (RONS) production and mitochondrial function of human vascular endothelial cells (HUVECs). We hypothesised that EPI would attenuate ROS production, increase NO bioavailability, and enhance indices of mitochondrial function. Methods. HUVECs were treated with EPI (0-20 μM) for up to 48 h. Mitochondrial and cellular ROS were measured in the absence and presence of antimycin A (AA), an inhibitor of the mitochondrial electron transport protein complex III, favouring ROS production. Genes associated with mitochondrial remodelling and the antioxidant response were quantified by RT-qPCR. Mitochondrial bioenergetics were assessed by respirometry and signalling responses determined by western blotting. Results. Mitochondrial superoxide production without AA was increased 32% and decreased 53% after 5 and 10 μM EPI treatment vs. CTRL ( P < 0.001 ). With AA, only 10 μM EPI increased mitochondrial superoxide production vs. CTRL (25%, P < 0.001 ). NO bioavailability was increased by 45% with 10 μM EPI vs. CTRL ( P = 0.010 ). However, EPI did not impact mitochondrial respiration. NRF2 mRNA expression was increased 1.5- and 1.6-fold with 5 and 10 μM EPI over 48 h vs. CTRL ( P = 0.015 and P = 0.001 , respectively). Finally, EPI transiently enhanced ERK1/2 phosphorylation (2.9 and 3.2-fold over 15 min and 1 h vs. 0 h, respectively; P = 0.035 and P = 0.011 ). Conclusion(s). EPI dose-dependently alters RONS production of HUVECs but does not impact mitochondrial respiration. The induction of NRF2 mRNA expression with EPI might relate to enhanced ERK1/2 signalling, rather than RONS production. In humans, EPI may improve vascular endothelial dysfunction via alteration of RONS and activation of cell signalling.

Dynamics of fibrotic and vascular endothelial dysfunction markers in elderly hypertensive patients after ischemic stroke receiving beta-blockers

Aim. To compare the effect of beta-blocker therapy (bisoprolol and nebivolol) on the dynamics of fibrotic and vascular endothelial dysfunction markers in elderly hypertensive patients after ischemic stroke (IS).Material and methods. This prospective cohort study included 75 hypertensive patients who were admitted to the hospital due to IS. The mean age of patients was 67±6 years. The average National Institutes of Health Stroke Scale (NIHSS) score was 7±3. The followup period was 6 months. The control group consisted of 20 elderly people with hypertension without prior myocardial infarction. The patients were divided into groups based on received therapy: group 1 (n=38) — bisoprolol; group 2 (n=37) — nebivolol. The level of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) was determined by enzyme-linked immunosorbent assay (ELISAKit, USA). Vascular ultrasound was carried out using a LOGIQP9 (GE) system according to the Celermajer method.Results. After 6-month nebivolol, we revealed a decrease in the level of MMP-9 by 30,2% (p<0,01), TIMP-1 by 15,6% (p<0,05). After 6-month bisoprolol therapy, the level of MMP-9 decreased by 14,5% (p<0,05), while TIMP-1 did not change. Intergroup comparison found that when using nebivolol, there was a higher decrease in the level of MMP-9 by 15,7% (p<0,05), TIMP-1 by 9,7% (p<0,05), MMP-9/TIMP-1 by 7,8% (p<0,05) than with bisoprolol therapy. After 6-month bisoprolol therapy, there was a decrease in the proportion of patients with severe endothelial dysfunction (ED) by 7,9% (p<0,05). Two patients from the nebivolol group moved into mild ED category. The number of patients with moderate ED increased by 19% (p<0,01), while prevalence of severe ED decreased by 24,4% (p<0,01).Conclusion. The results obtained indicate that the beta-blocker nebivolol at an average dose of 8,55+1,75 mg/day significantly reduces the vascular fibrosis, normalizes the ratio of collagen synthesis and degradation markers, improves the vasodilation brachial artery properties in comparison with bisoprolol in elderly hypertensive patients after IS.

Proteomic profiling of MIS-C patients indicates heterogeneity relating to interferon gamma dysregulation and vascular endothelial dysfunction

Multi-system Inflammatory Syndrome in Children (MIS-C) is a major complication of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in pediatric patients. Weeks after an often mild or asymptomatic initial infection with SARS-CoV-2 children may present with a severe shock-like picture and marked inflammation. Children with MIS-C present with varying degrees of cardiovascular and hyperinflammatory symptoms. Here we perform a comprehensive analysis of the plasma proteome of more than 1400 proteins in children with SARS-CoV-2. We hypothesize that the proteome would reflect heterogeneity in hyperinflammation and vascular injury, and further identify pathogenic mediators of disease. We show that protein signatures demonstrate overlap between MIS-C, and the inflammatory syndromes macrophage activation syndrome (MAS) and thrombotic microangiopathy (TMA). We demonstrate that PLA2G2A is an important marker of MIS-C that associates with TMA. We find that IFNγ responses are dysregulated in MIS-C patients, and that IFNγ levels delineate clinical heterogeneity.

(—)-Epicatechin alters reactive oxygen and nitrogen species production independent of mitochondrial respiration in human vascular endothelial cells

Introduction: Vascular endothelial dysfunction is characterised by lowered nitric oxide (NO) bioavailability, which may be explained by increased production of reactive oxygen species (ROS), mitochondrial dysfunction and altered cell signalling. (—)-Epicatechin (EPI) has proven effective in the context of vascular endothelial dysfunction, but the underlying mechanisms associated with EPIs effects remain unclear. Objective(s): Our aim was to investigate whether EPI impacts reactive oxygen and nitrogen species (RONS) production and mitochondrial function of human vascular endothelial cells (HUVECs). We hypothesised that EPI would attenuate ROS production, increase NO bioavailability, and enhance indices of mitochondrial function. Methods: HUVECs were treated with EPI (0-20 μM) for up to 48 h. Mitochondrial and cellular ROS were measured in the absence and presence of antimycin A (AA), an inhibitor of the mitochondrial electron transport protein complex III, favouring ROS production. Genes associated with mitochondrial remodelling and the antioxidant response were quantified by RT-qPCR. Mitochondrial bioenergetics were assessed by respirometry and signalling responses determined by western blotting. Results: Mitochondrial superoxide production without AA was increased 32% and decreased 53% after 5 and 10 μM EPI treatment vs. CTRL (P<0.001). With AA, only 10 μM EPI increased mitochondrial superoxide production vs. CTRL (25%, P<0.001). NO bioavailability was increased by 45% with 10 μM EPI vs. CTRL (P=0.010). However, EPI did not impact mitochondrial respiration. NRF2 mRNA expression was increased 1.5- and 1.6-fold with 5 and 10 μM EPI over 48 h vs. CTRL (P=0.015 and P=0.001, respectively). Finally, EPI transiently enhanced ERK1/2 phosphorylation (2.9 and 3.2-fold over 15 min and 1 h vs. 0 h, respectively; P=0.035 and P=0.011). Conclusion(s): EPI dose dependently alters RONS production of HUVECs but does not impact mitochondrial respiration. The induction of NRF2 mRNA expression with EPI might relate to enhanced ERK1/2 signalling, rather than RONS production. In humans, EPI may improve vascular endothelial dysfunction via alteration of RONS and activation of cell signalling.