Objective- Gut microbiota-dependent metabolites, in particular trimethylamine N-oxide (TMAO), have recently been reported to promote atherosclerosis and thrombosis. Here, we examined for the first time the relation of TMAO and the risk of incident cardiovascular events in patients with recent first-ever ischemic stroke in 2 independent prospective cohorts. Moreover, the link between TMAO and proinflammatory monocytes as a potential contributing factor for cardiovascular risk in stroke patients was studied. Approach and Results- In a first study (n=78), higher TMAO plasma levels were linked with an increased risk of incident cardiovascular events including myocardial infarction, recurrent stroke, and cardiovascular death (fourth quartile versus first quartile; hazard ratio, 2.31; 95% CI, 1.25-4.23; P<0.01). In the second independent validation cohort (n=593), high TMAO levels again heralded marked increased risk of adverse cardiovascular events (fourth quartile versus first quartile; hazard ratio, 5.0; 95% CI, 1.7-14.8; P<0.01), and also after adjustments for cardiovascular risk factors including hypertension, diabetes mellitus, LDL (low-density lipoprotein) cholesterol, and estimated glomerular filtration rate (hazard ratio, 3.3; 95% CI, 1.2-10.9; P=0.04). A significant correlation was also found between TMAO levels and percentage of proinflammatory intermediate CD14CD16 monocytes ( r=0.70; P<0.01). Moreover, in mice fed a diet enriched with choline to increase TMAO synthesis, levels of proinflammatory murine Ly6C monocytes were higher than in the chow-fed control group (choline: 9.2±0.5×10 per mL versus control: 6.5±0.5×10 per mL; P<0.01). This increase was abolished in mice with depleted gut microbiota (choline+antibiotics: 5.4±0.7×10 per mL; P<0.001 versus choline). Conclusions- The present study demonstrates for the first time a graded relation between TMAO levels and the risk of subsequent cardiovascular events in patients with recent prior ischemic stroke. Our data support the notion that TMAO-related increase of proinflammatory monocytes may add to elevated cardiovascular risk of patients with increased TMAO levels.

Aims Coronavirus disease 2019 (COVID‐19) is a still growing pandemic, causing many deaths and socio‐economic damage. Elevated expression of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) entry receptor angiotensin‐converting enzyme 2 on cardiac cells of patients with heart diseases may be related to cardiovascular burden. We have thus analysed cardiovascular and inflammatory microRNAs (miRs), sensitive markers of cardiovascular damage, in critically ill, ventilated patients with COVID‐19 or influenza‐associated acute respiratory distress syndrome (Influenza‐ARDS) admitted to the intensive care unit and healthy controls. Methods and results Circulating miRs (miR‐21, miR‐126, miR‐155, miR‐208a, and miR‐499) were analysed in a discovery cohort consisting of patients with mechanically‐ventilated COVID‐19 ( n = 18) and healthy controls ( n = 15). A validation study was performed in an independent cohort of mechanically‐ventilated COVID‐19 patients ( n = 20), Influenza‐ARDS patients ( n = 13) and healthy controls ( n = 32). In both cohorts, RNA was isolated from serum and cardiovascular disease/inflammatory‐relevant miR concentrations were measured by miR‐specific TaqMan PCR analyses. In both the discovery and the validation cohort, serum concentration of miR‐21, miR‐155, miR‐208a and miR‐499 were significantly increased in COVID‐19 patients compared to healthy controls. Calculating the area under the curve using receiver operating characteristic analysis miR‐155, miR‐208a and miR‐499 showed a clear distinction between COVID‐19 and Influenza‐ARDS patients. Conclusion In this exploratory study, inflammation and cardiac myocyte‐specific miRs were upregulated in critically ill COVID‐19 patients. Importantly, miR profiles were able to differentiate between severely ill, mechanically‐ventilated Influenza‐ARDS and COVID‐19 patients, indicating a rather specific response and cardiac involvement of COVID‐19.

S-nitrosothiols

GATA2-mediated regulation of miR-126 and miR-221 has an important impact on endothelial biology. Hence, modulation of GATA2 and its targets miR-126 and miR-221 is a promising therapeutic strategy for treatment of many vascular diseases.

The initial activation of adventitial fibroblasts is essential for the subsequent proliferation of SMC and neointima formation. We identified SMO-dependent Shh signalling as a specific process for the activation of adventitial fibroblasts.