Deleterious Anti-Inflammatory Macrophage Recruitment in Early Post-Infarction Phase: Unraveling the IL-6/MCP-1/STAT3 Axis.

Using a translational approach with an ST-segment myocardial infarction (STEMI) cohort and mouse model of myocardial infarction, we highlighted the role of the secreted IL-6 and MCP-1 cytokines and the STAT3 pathway in heart macrophage recruitment and activation. Cardiac myocytes secrete IL-6 and MCP-1 in response to hypoxic stress, leading to a recruitment and/or polarization of anti-inflammatory macrophages via the STAT3 pathway. In our preclinical model of myocardial infarction, neutralization of IL-6 and MCP-1 or STAT3 pathway reduced infarct size. Together, our data demonstrate that anti-inflammatory macrophages can be deleterious in the acute phase of STEMI.

Myocardial transcriptomic analysis of diabetic patients with aortic stenosis: key role for mitochondrial calcium signaling.

BACKGROUND: Type 2 diabetes (T2D) is a frequent comorbidity encountered in patients with severe aortic stenosis (AS), leading to an adverse left ventricular (LV) remodeling and dysfunction. Metabolic alterations have been suggested as contributors of the deleterious effect of T2D on LV remodeling and function in patients with severe AS, but so far, the underlying mechanisms remain unclear. Mitochondria play a central role in the regulation of cardiac energy metabolism. OBJECTIVES: We aimed to explore the mitochondrial alterations associated with the deleterious effect of T2D on LV remodeling and function in patients with AS, preserved ejection fraction, and no additional heart disease. METHODS: We combined an in-depth clinical, biological and echocardiography phenotype of patients with severe AS, with (n = 34) or without (n = 50) T2D, referred for a valve replacement, with transcriptomic and histological analyses of an intra-operative myocardial LV biopsy. RESULTS: T2D patients had similar AS severity but displayed worse cardiac remodeling, systolic and diastolic function than non-diabetics. RNAseq analysis identified 1029 significantly differentially expressed genes. Functional enrichment analysis revealed several T2D-specific upregulated pathways despite comorbidity adjustment, gathering regulation of inflammation, extracellular matrix organization, endothelial function/angiogenesis, and adaptation to cardiac hypertrophy. Downregulated gene sets independently associated with T2D were related to mitochondrial respiratory chain organization/function and mitochondrial organization. Generation of causal networks suggested a reduced Ca2+ signaling up to the mitochondria, with the measured gene remodeling of the mitochondrial Ca2+ uniporter in favor of enhanced uptake. Histological analyses supported a greater cardiomyocyte hypertrophy and a decreased proximity between the mitochondrial VDAC porin and the reticular IP3-receptor in T2D. CONCLUSIONS: Our data support a crucial role for mitochondrial Ca2+ signaling in T2D-induced cardiac dysfunction in severe AS patients, from a structural reticulum-mitochondria Ca2+ uncoupling to a mitochondrial gene remodeling. Thus, our findings open a new therapeutic avenue to be tested in animal models and further human cardiac biopsies in order to propose new treatments for T2D patients suffering from AS. TRIAL REGISTRATION: URL: https://www. CLINICALTRIALS: gov ; Unique Identifier: NCT01862237.

Oxidation-reduction imaging of myoglobin reveals two-phase oxidation in the reperfused myocardium.

Myocardial infarction (MI) is a serious acute cardiovascular syndrome that causes myocardial injury due to blood flow obstruction to a specific myocardial area. Under ischemic-reperfusion settings, a burst of reactive oxygen species is generated, leading to redox imbalance that could be attributed to several molecules, including myoglobin. Myoglobin is dynamic and exhibits various oxidation-reduction states that have been an early subject of attention in the food industry, specifically for meat consumers. However, rarely if ever have the myoglobin optical properties been used to measure the severity of MI. In the current study, we develop a novel imaging pipeline that integrates tissue clearing, confocal and light sheet fluorescence microscopy, combined with imaging analysis, and processing tools to investigate and characterize the oxidation-reduction states of myoglobin in the ischemic area of the cleared myocardium post-MI. Using spectral imaging, we have characterized the endogenous fluorescence of the myocardium and demonstrated that it is partly composed by fluorescence of myoglobin. Under ischemia-reperfusion experimental settings, we report that the infarcted myocardium spectral signature is similar to that of oxidized myoglobin signal that peaks 3 h post-reperfusion and decreases with cardioprotection. The infarct size assessed by oxidation-reduction imaging at 3 h post-reperfusion was correlated to the one estimated with late gadolinium enhancement MRI at 24 h post-reperfusion. In conclusion, this original work suggests that the redox state of myoglobin can be used as a promising imaging biomarker for characterizing and estimating the size of the MI during early phases of reperfusion.

Colchicine in acute myocardial infarction: cardiovascular events at 1-year follow up.

OBJECTIVE: In the COVERT-MI randomised placebo-controlled trial, oral administration of high-dose colchicine at the time of reperfusion and for 5 days in acute ST-elevated myocardial infarction did not reduce infarct size but was associated with a significant increase in left ventricular thrombus (LVT) in comparison to placebo. We aimed to assess the 1-year clinical outcomes of the study population. METHODS: This study is a follow-up analysis of the COVERT-MI study on prespecified secondary clinical endpoints at 1 year. The primary endpoint of this study was a composite of major adverse cardiovascular events (MACEs), including all-cause death, acute coronary syndromes, heart failure events, ischaemic strokes, sustained ventricular arrhythmias and acute kidney injury at 1-year follow-up. The quality of life (QOL) and the drug therapy prescription were also assessed. RESULTS: At 1 year, 192 patients (101 patients in the colchicine group, 91 in the placebo group) were followed up. Seventy-six (39.6%) MACEs were reported in the study population. There was no significant difference regarding the number of MACEs between groups: 36 (35.6%) in the colchicine group and 40 (44.1%) in the placebo group (p=0.3). There were no differences in the occurrence of ischaemic strokes between the colchicine group and the control group (3 (3%) vs 2 (2.2%), respectively, p=0.99). There was a trend towards fewer heart failure events in the colchicine group compared with the placebo group (12 (11.9%) vs 18 (19.8%), p=0.20). There was no significant difference in QOL scores at 1 year (75.8±15.7 vs 72.7±16.2 respectively, p=0.18). CONCLUSIONS: There was no significant difference between the colchicine and placebo groups at 1 year regarding MACEs, especially concerning deaths or ischaemic strokes. No excess of ischaemic adverse events was observed despite the initial increase in LVT in the colchicine group. TRIAL REGISTRATION NUMBER: NCT0315681.