Temporal transcriptional changes in human monocytes following acute myocardial infarction: The GerMIFs monocyte expression study
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ABSTRACT: Monocytes play a central role in the inflammatory response that follows acute myocardial infarction (MI). In order to study phenotypic adaptation of this cell type, we investigated patterns of monocyte gene expression in circulating monocytes at various stages of MI. Circulating monocytes were isolated from venous blood of MI patients at three time points: t1: within 6 hours after onset of chest pain (acute phase), t2: 3 days after MI (subacute phase), t3: 90 days after MI (chronic phase). For comparison, we studied a control group (n=21, data to be submitted later) with stable coronary artery disease. Using this transcriptomic analysis, we aimed to provide a more comprehensive reference of monocyte biology following acute MI and to aid in the identification of novel pathways and genes influencing the course of MI. Monocytes play a central role in the inflammatory response that follows acute myocardial infarction (MI). In order to study phenotypic adaptation of this cell type, we investigated patterns of monocyte gene expression in circulating monocytes at various stages of MI. Circulating monocytes were isolated from venous blood of MI patients at three time points: t1: within 6 hours after onset of chest pain (acute phase), t2: 3 days after MI (subacute phase), t3: 90 days after MI (chronic phase). For comparison, we studied a control group (n=21, data to be submitted later) with stable coronary artery disease. Illumina Ref-8 v3.0 microarray arrays were used for whole-genome transcriptional profiling.
Project description:Monocytes play a central role in the inflammatory response that follows acute myocardial infarction (MI). In order to study phenotypic adaptation of this cell type, we investigated patterns of monocyte gene expression in circulating monocytes at various stages of MI. Circulating monocytes were isolated from venous blood of MI patients at three time points: t1: within 6 hours after onset of chest pain (acute phase), t2: 3 days after MI (subacute phase), t3: 90 days after MI (chronic phase). For comparison, we studied a control group (n=21, data to be submitted later) with stable coronary artery disease. Using this transcriptomic analysis, we aimed to provide a more comprehensive reference of monocyte biology following acute MI and to aid in the identification of novel pathways and genes influencing the course of MI. Monocytes play a central role in the inflammatory response that follows acute myocardial infarction (MI). In order to study phenotypic adaptation of this cell type, we investigated patterns of monocyte gene expression in circulating monocytes at various stages of MI. Circulating monocytes were isolated from venous blood of MI patients at three time points: t1: within 6 hours after onset of chest pain (acute phase), t2: 3 days after MI (subacute phase), t3: 90 days after MI (chronic phase). For comparison, we studied a control group (n=21, data to be submitted later) with stable coronary artery disease. Illumina Ref-8 v3.0 microarray arrays were used for whole-genome transcriptional profiling.
Project description:Monocytes play a central role in the inflammatory response that follows acute myocardial infarction (MI). In order to study phenotypic adaptation of this cell type, we investigated patterns of monocyte gene expression in circulating monocytes at various stages of MI. Circulating monocytes were isolated from venous blood of MI patients at three time points: t1: within 6 hours after onset of chest pain (acute phase), t2: 3 days after MI (subacute phase), t3: 90 days after MI (chronic phase). For comparison, we studied a control group (n=21, data to be submitted later) with stable coronary artery disease. Using this transcriptomic analysis, we aimed to provide a more comprehensive reference of monocyte biology following acute MI and to aid in the identification of novel pathways and genes influencing the course of MI.
Project description:BackgroundPreclinical data suggest that an acute inflammatory response following myocardial infarction (MI) accelerates systemic atherosclerosis. Using combined positron emission and computed tomography, we investigated whether this phenomenon occurs in humans.Methods and resultsOverall, 40 patients with MI and 40 with stable angina underwent thoracic 18F-fluorodeoxyglucose combined positron emission and computed tomography scan. Radiotracer uptake was measured in aortic atheroma and nonvascular tissue (paraspinal muscle). In 1003 patients enrolled in the Global Registry of Acute Coronary Events, we assessed whether infarct size predicted early (≤30 days) and late (>30 days) recurrent coronary events. Compared with patients with stable angina, patients with MI had higher aortic 18F-fluorodeoxyglucose uptake (tissue-to-background ratio 2.15±0.30 versus 1.84±0.18, P<0.0001) and plasma C-reactive protein concentrations (6.50 [2.00 to 12.75] versus 2.00 [0.50 to 4.00] mg/dL, P=0.0005) despite having similar aortic (P=0.12) and less coronary (P=0.006) atherosclerotic burden and similar paraspinal muscular 18F-fluorodeoxyglucose uptake (P=0.52). Patients with ST-segment elevation MI had larger infarcts (peak plasma troponin 32 300 [10 200 to >50 000] versus 3800 [1000 to 9200] ng/L, P<0.0001) and greater aortic 18F-fluorodeoxyglucose uptake (2.24±0.32 versus 2.02±0.21, P=0.03) than those with non-ST-segment elevation MI. Peak plasma troponin concentrations correlated with aortic 18F-fluorodeoxyglucose uptake (r=0.43, P=0.01) and, on multivariate analysis, independently predicted early (tertile 3 versus tertile 1: relative risk 4.40 [95% CI 1.90 to 10.19], P=0.001), but not late, recurrent MI.ConclusionsThe presence and extent of MI is associated with increased aortic atherosclerotic inflammation and early recurrent MI. This finding supports the hypothesis that acute MI exacerbates systemic atherosclerotic inflammation and remote plaque destabilization: MI begets MI.Clinical trial registrationURL: https://www.clinicaltrials.gov. Unique identifier: NCT01749254.
Project description:Maladaptive repair contributes towards the development of heart failure following myocardial infarction (MI). The αvβ3 integrin receptor is a key mediator and determinant of cardiac repair. We aimed to establish whether αvβ3 integrin expression determines myocardial recovery following MI.18F-Fluciclatide (a novel αvβ3-selective radiotracer) positron emission tomography (PET) and CT imaging and gadolinium-enhanced MRI (CMR) were performed in 21 patients 2 weeks after ST-segment elevation MI (anterior, n=16; lateral, n=4; inferior, n=1). CMR was repeated 9 months after MI. 7 stable patients with chronic total occlusion (CTO) of a major coronary vessel and nine healthy volunteers underwent a single PET/CT and CMR.18F-Fluciclatide uptake was increased at sites of acute infarction compared with remote myocardium (tissue-to-background ratio (TBRmean) 1.34±0.22 vs 0.85±0.17; p<0.001) and myocardium of healthy volunteers (TBRmean 1.34±0.22 vs 0.70±0.03; p<0.001). There was no 18F-fluciclatide uptake at sites of established prior infarction in patients with CTO, with activity similar to the myocardium of healthy volunteers (TBRmean 0.71±0.06 vs 0.70±0.03, p=0.83). 18F-Fluciclatide uptake occurred at sites of regional wall hypokinesia (wall motion index≥1 vs 0; TBRmean 0.93±0.31 vs 0.80±0.26 respectively, p<0.001) and subendocardial infarction. Importantly, although there was no correlation with infarct size (r=0.03, p=0.90) or inflammation (C reactive protein, r=-0.20, p=0.38), 18F-fluciclatide uptake was increased in segments displaying functional recovery (TBRmean 0.95±0.33 vs 0.81±0.27, p=0.002) and associated with increase in probability of regional recovery.18F-Fluciclatide uptake is increased at sites of recent MI acting as a biomarker of cardiac repair and predicting regions of recovery.NCT01813045; Post-results.
Project description:IntroductionMetabolic reprogramming from glycolysis to the mitochondrial tricarboxylic acid (TCA) cycle and oxidative phosphorylation may mediate macrophage polarization from the pro-inflammatory M1 to the anti-inflammatory M2 phenotype. We hypothesized that changes in cardiac macrophage glucose metabolism would reflect polarization status after myocardial infarction (MI), ranging from the early inflammatory phase to the later wound healing phase.MethodsMI was induced by permanent ligation of the left coronary artery in adult male C57BL/6J mice for 1 (D1), 3 (D3), or 7 (D7) days. Infarct macrophages were subjected to metabolic flux analysis or gene expression analysis. Monocyte versus resident cardiac macrophage metabolism was assessed using mice lacking the Ccr2 gene (CCR2 KO).ResultsBy flow cytometry and RT-PCR, D1 macrophages exhibited an M1 phenotype while D7 macrophages exhibited an M2 phenotype. Macrophage glycolysis (extracellular acidification rate) was increased at D1 and D3, returning to basal levels at D7. Glucose oxidation (oxygen consumption rate) was decreased at D3, returning to basal levels at D7. At D1, glycolytic genes were elevated (Gapdh, Ldha, Pkm2), while TCA cycle genes were elevated at D3 (Idh1 and Idh2) and D7 (Pdha1, Idh1/2, Sdha/b). Surprisingly, Slc2a1 and Hk1/2 were increased at D7, as well as pentose phosphate pathway (PPP) genes (G6pdx, G6pd2, Pgd, Rpia, Taldo1), indicating increased PPP activity. Macrophages from CCR2 KO mice showed decreased glycolysis and increased glucose oxidation at D3, and decreases in Ldha and Pkm2 expression. Administration of dichloroacetate, a pyruvate dehydrogenase kinase inhibitor, robustly decreased pyruvate dehydrogenase phosphorylation in the non-infarcted remote zone, but did not affect macrophage phenotype or metabolism in the infarct zone.DiscussionOur results indicate that changes in glucose metabolism and the PPP underlie macrophage polarization following MI, and that metabolic reprogramming is a key feature of monocyte-derived but not resident macrophages.
Project description:In this research, we hypothesized that novel biomechanical parameters are discriminative in patients following acute ST-segment elevation myocardial infarction (STEMI). To identify these biomechanical biomarkers and bring computational biomechanics 'closer to the clinic', we applied state-of-the-art multiphysics cardiac modelling combined with advanced machine learning and multivariate statistical inference to a clinical database of myocardial infarction. We obtained data from 11 STEMI patients (ClinicalTrials.gov NCT01717573) and 27 healthy volunteers, and developed personalized mathematical models for the left ventricle (LV) using an immersed boundary method. Subject-specific constitutive parameters were achieved by matching to clinical measurements. We have shown, for the first time, that compared with healthy controls, patients with STEMI exhibited increased LV wall active tension when normalized by systolic blood pressure, which suggests an increased demand on the contractile reserve of remote functional myocardium. The statistical analysis reveals that the required patient-specific contractility, normalized active tension and the systolic myofilament kinematics have the strongest explanatory power for identifying the myocardial function changes post-MI. We further observed a strong correlation between two biomarkers and the changes in LV ejection fraction at six months from baseline (the required contractility (r = - 0.79, p < 0.01) and the systolic myofilament kinematics (r = 0.70, p = 0.02)). The clinical and prognostic significance of these biomechanical parameters merits further scrutinization.
Project description:Neutrophils and monocytes through their CD15s, CD11b and CD44 adhesion molecules are implicated in the initiation and resolution of cardiac inflammation as well as in healing processes after the myocardial infarction (MI). The aim of this study was to determine the effect of white wine consumption on granulocyte and monocyte CD15s, CD11b, and CD44 expression 24h after the surgically inflicted MI. Granulocytes and monocytes were analyzed by flow cytometry, using whole blood of male Sprague-Dawley rats that consumed white wine for 4 weeks. This group was compared with water only drinking controls, sham animals (subject to surgery without myocardial infarction) and baseline group (intact animals that received no intervention prior to being sacrificed). Sham animals did not differ from baseline animals in CD11b+CD44+ percentage and CD44+ median fluorescence intensity. Wine drinking was associated with striking increase in CD44 expression on monocyte subpopulations. Its expression was three and fourfold increased on monocytes and large monocytes, respectively, relative to the water only drinking controls. Because of known role of CD44 on suppression of post-infarction inflammation, its upregulation on granulocytes and monocytes may significantly contribute to the microenvironment favourable for the cardiac regeneration.
Project description:Ventricular septal rupture is a rare and potentially fatal complication of transmural myocardial infarction. Early identification utilising transthoracic echocardiography significantly improves long term outcomes in these patients. We report on a case of a 77-year-old male who presented with signs and symptoms of cardiac failure and a loud systolic murmur. The patient underwent an initial point-of-care ultrasound which revealed evidence of a transmural myocardial infarction and a high suspicion of an apical ventricular septal rupture. A complete transthoracic echocardiogram confirmed the septal rupture diagnosis and the patient subsequently underwent surgical repair of the ventricular rupture. This case highlights the role of echocardiography in decreasing adverse outcomes in patients with ventricular septal rupture.
Project description:BackgroundStrain analyses derived from cardiovascular magnetic resonance-feature tracking (CMR-FT) provide incremental prognostic benefit in patients sufferring from acute myocardial infarction (AMI). This study aims to evaluate and revalidate previously reported prognostic implications of comprehensive strain analyses in a large independent cohort of patients with ST-elevation myocardial infarction (STEMI).MethodsOverall, 566 STEMI patients enrolled in the CONDITIONING-LIPSIA trial including pre- and/or postconditioning treatment in addition to conventional percutaneous coronary intervention underwent CMR imaging in median 3 days after primary percutaneous coronary intervention. CMR-based left atrial (LA) reservoir (Es), conduit (Ee), and boosterpump (Ea) strain analyses, as well as left ventricular (LV) global longitudinal strain (GLS), circumferential strain (GCS), and radial strain (GRS) analyses were carried out. Previously identified cutoff values were revalidated for risk stratification. Major adverse cardiac events (MACE) comprising death, reinfarction, and new congestive heart failure were assessed within 12 months after the occurrence of the index event.ResultsBoth atrial and ventricular strain values were significantly reduced in patients with MACE (p < 0.01 for all). Predetermined LA and LV strain cutoffs enabled accurate risk assessment. All LA and LV strain values were associated with MACE on univariable regression modeling (p < 0.001 for all), with LA Es emerging as an independent predictor of MACE on multivariable regression modeling (HR 0.92, p = 0.033). Furthermore, LA Es provided an incremental prognostic value above LVEF (a c-index increase from 0.7 to 0.74, p = 0.03).ConclusionExternal validation of CMR-FT-derived LA and LV strain evaluations confirmed the prognostic value of cardiac deformation assessment in STEMI patients. In the present study, LA strain parameters especially enabled further risk stratification and prognostic assessment over and above clinically established risk parameters.Clinical trial registrationClinicalTrials.gov, identifier NCT02158468.
Project description:BackgroundThe quality of the relationship between a patient and their usual source of care may impact outcomes, especially after an acute clinical event requiring regular follow-up.ObjectiveTo examine the association between the presence and strength of a usual source of care with mortality and readmission after hospitalization for acute myocardial infarction (AMI).DesignProspective Registry Evaluating Myocardial Infarction: Event and Recovery (PREMIER), an observational, 19-center study.PatientsAMI patients discharged between January 2003 and June 2004.Main measuresThe strength of the usual source of care was categorized as none, weak, or strong based upon the duration and familiarity of the relationship. Main outcome measures were readmissions and mortality at 6 months and 12 months post-AMI, examined in multivariable analysis adjusting for socio-demographic characteristics, access and barriers to care, financial status, baseline risk factors, and AMI severity.Key resultsAmong 2,454 AMI patients, 441 (18.0 %) reported no usual source of care, whereas 247 (10.0 %) and 1,766 (72.0 %) reported weak and strong usual sources of care, respectively. When compared with a strong usual source of care, adults with no usual source of care had higher 6-month mortality rates [adjusted hazard ratio (aHR)?=?3.15, 95 % CI, 1.79-5.52; p?<?0.001] and 12-month mortality rates (aHR?=?1.92, 95 % CI, 1.19-3.12; p?=?0.01); adults with a weak usual source of care trended toward higher mortality at 6 months (aHR?=?1.95, 95 % CI, 0.98-3.88; p?=?0.06), but not 12 months (p?=?0.23). We found no association between the usual source of care and readmissions.ConclusionsAdults with no or weak usual sources of care have an increased risk for mortality following AMI, but not for readmission.