Impact of the SGLT2-inhibitor empagliflozin on inflammatory biomarkers after acute myocardial infarction - a post-hoc analysis of the EMMY trial.

BACKGROUND: SGTL2-inhibitors are a cornerstone in the treatment of heart failure, but data on patients with acute myocardial infarction (AMI) is limited. The EMMY trial was the first to show a significant reduction in NTproBNP levels as well as improved cardiac structure and function in post-AMI patients treated with Empagliflozin compared to placebo. However, data on the potential impact of SGLT2-inhibitors on inflammatory biomarkers after AMI are scarce. MATERIALS AND METHODS: The EMMY trial is an investigator-initiated, multicentre, double-blind, placebo-controlled trial, which enrolled patients after AMI, receiving either 10 mg Empagliflozin once daily or placebo over a period of 26 weeks on top of standard guideline-recommended therapy starting within 72 h after percutaneous coronary intervention. In this post-hoc subgroup analysis of the EMMY trial, we investigated inflammatory biomarkers of 374 patients. The endpoints investigated were the mean change in inflammatory biomarkers such as high-sensitive c-reactive protein (hsCRP), interleukin-6 (IL-6), neutrophils, leukocytes, neutrophile/lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) from baseline to 26 weeks. RESULTS: Baseline median (interquartile ranges) IL-6 was 17.9 pg/mL (9.0-38.7), hsCRP 18.9 mg/L (11.2-37.1), neutrophil count 7.9 x G/L (6.2-10.1), leukocyte count 10.8 x G/L (9.1-12.8) and neutrophile/lymphocyte ratio (NLR) of 0.74 (0.67-0.80). At week 26, a significant mean reduction in inflammatory biomarkers was observed, being 35.1 ± 3.2% (p < 0.001) for IL-6, 57.4 ± 0.7% (p < 0.001) for hsCRP, 26.1 ± 0.7% (p < 0.001) for neutrophils, 20.5 ± 0.6% (p < 0.001) for leukocytes, 10.22 ± 0.50% (p < 0.001) for NLR, and - 2.53 ± 0.92% for PLR (p = 0.006) with no significant difference between Empagliflozin and placebo treatment. CONCLUSION: Trajectories of inflammatory biomarkers showed a pronounced decline after AMI, but Empagliflozin treatment did not impact this decline indicating no central role in blunted systemic inflammation mediating beneficial effects.

Transesophageal echocardiography-guided versus fluoroscopy-guided patent foramen ovale closure: A single center registry.

BACKGROUND: Percutaneous closure of patent foramen ovale (PFO) is conventionally performed under continuous transesophageal echocardiographic (TEE) guidance. We aimed to evaluate whether a simplified procedural approach, including pure fluoroscopy-guidance and final TEE control, as well as an aimed 'next-day-discharge' is comparable with the conventional TEE-guided procedure in terms of periprocedural and intermediate-term outcomes. METHODS: All patients who underwent a PFO closure at our center between 2010 and 2022 were retrospectively included. Prior to June 2019 cases were performed with continuous TEE guidance (TEE-guided group). Since June 2019, only pure fluoroscopy-guided PFO closures have been performed with TEE insertion and control just prior to device release (fluoroscopy-guided group). We analyzed procedural aspects, as well as long term clinical and echocardiographic outcomes. RESULTS: In total 291 patients were included in the analysis: 197 in the TEE-guided group and 94 in the fluoroscopy-guided group. Fluoroscopy-guided procedures were markedly shorter (48 ± 20 min vs. 25 ± 9 min; p < .01). There was no difference in procedural complications, including death, major bleeding, device dislodgement, stroke or clinically relevant peripheral embolization between the two groups (.5% vs. 0%; p = .99). Hospital stay was also shorter with the simplified approach (2.5 ± 1.6 vs. 3.5 ± 1.2 days; p < .01), allowing 85% same-day discharges during the last 12 months of observation period. At 6 ± 3 months echocardiographic follow-up a residual leakage was described in 8% of the TEE-guided cases and 2% of the fluoroscopy-guided cases (p = .08). CONCLUSION: While a complete TEE-free PFO closure might have potential procedural risks, our approach of pure fluoroscopy-guided with a brisk final TEE check seems to be advantageous in terms of procedural aspects with no sign of any acute or intermediate-term hazard and it could offer an equitable compromise between the two worlds: a complete TEE procedure and a procedure without any TEE.

Empagliflozin in acute myocardial infarction: the EMMY trial.

AIMS: Sodium-glucose co-transporter 2 inhibition reduces the risk of hospitalization for heart failure and for death in patients with symptomatic heart failure. However, trials investigating the effects of this drug class in patients following acute myocardial infarction are lacking. METHODS AND RESULTS: In this academic, multicentre, double-blind trial, patients (n = 476) with acute myocardial infarction accompanied by a large creatine kinase elevation (>800 IU/L) were randomly assigned to empagliflozin 10 mg or matching placebo once daily within 72 h of percutaneous coronary intervention. The primary outcome was the N-terminal pro-hormone of brain natriuretic peptide (NT-proBNP) change over 26 weeks. Secondary outcomes included changes in echocardiographic parameters. Baseline median (interquartile range) NT-proBNP was 1294 (757-2246) pg/mL. NT-proBNP reduction was significantly greater in the empagliflozin group, compared with placebo, being 15% lower [95% confidence interval (CI) -4.4% to -23.6%] after adjusting for baseline NT-proBNP, sex, and diabetes status (P = 0.026). Absolute left-ventricular ejection fraction improvement was significantly greater (1.5%, 95% CI 0.2-2.9%, P = 0.029), mean E/e' reduction was 6.8% (95% CI 1.3-11.3%, P = 0.015) greater, and left-ventricular end-systolic and end-diastolic volumes were lower by 7.5 mL (95% CI 3.4-11.5 mL, P = 0.0003) and 9.7 mL (95% CI 3.7-15.7 mL, P = 0.0015), respectively, in the empagliflozin group, compared with placebo. Seven patients were hospitalized for heart failure (three in the empagliflozin group). Other predefined serious adverse events were rare and did not differ significantly between groups. CONCLUSION: In patients with a recent myocardial infarction, empagliflozin was associated with a significantly greater NT-proBNP reduction over 26 weeks, accompanied by a significant improvement in echocardiographic functional and structural parameters. CLINICALTRIALS.GOV REGISTRATION: NCT03087773.

Changes in Lipoprotein(a) Levels in People after ST Elevation Myocardial Infarction-The STEMI-Lipids Study.

Lipoprotein(a) (Lp(a)) is considered an independent risk factor for cardiovascular diseases. The plasma concentration of Lp(a) is largely genetically determined but varies over a wide range within the population. This study investigated changes in Lp(a) levels after an acute myocardial infarction. Patients who underwent coronary angiography due to an ST elevation myocardial infarction were enrolled (n = 86), and Lp(a) levels were measured immediately after the intervention, one day, two days, and at a post-discharge follow-up visit at 3 to 6 months after the acute myocardial infarction. Median Lp(a) levels increased from a median of 7.9 mg/dL (3.8-37.1) at hospital admission to 8.4 mg/dL (3.9-35.4) on the following day, then to 9.3 mg/dL (3.7-39.1) on day two (p < 0.001), and to 11.2 mg/dL (4.4-59.6) at the post-discharge follow-up (p < 0.001). Lp(a) levels were the lowest during the acute myocardial infarction and started to increase significantly immediately thereafter, with the highest levels at the post-discharge follow-up. The moderate but significant increase in Lp(a) in people with acute myocardial infarction appears to be clinically relevant on an individual basis, especially when specific Lp(a) cut-off levels are supposed to determine the initiation of future treatment. Hence, a repeated measurement of Lp(a) after myocardial infarction should be performed.

Ertugliflozin to reduce arrhythmic burden in ICD/CRT patients (ERASe-trial) - A phase III study.

Sodium glucose cotransporter 2 (SGLT2) have proven profound positive effects in heart failure with reduced ejection fraction (HFrEF). These effects are independent from the presence of diabetes. Metabolic effects, antiinflammatory, and antifibrotic properties are discussed as underlying mechanisms. Despite a strong correlation of ventricular arrhythmias with HFrEF, the impact of ertugliflozin on the ventricular arrhythmic burden has not been investigated, yet. Therefore, the Ertugliflozin to Reduce Arrhythmic burden in ICD ± CRT patientS (ERASe) trial was designed to investigate the efficacy and safety of ertugliflozin in patients with reduced and midrange ejection fraction (EF) with or without diabetes. METHODS: Within a multicentre, national, randomized, double-blind, placebo-controlled, phase 3b trial we aim to enrol a total of 402 patients across Austria. Patients with reduced or midrange EF and ICD ± CRT therapy >3 months and previous ventricular tachycardia (at least 10 documented VT episodes within the last 12 months) are randomized in a 1:1 ratio to ertugliflozin (5 mg once daily orally administered) or matching placebo. The primary endpoint of the ERASe trial is to investigate the impact of ertugliflozin on total burden of ventricular arrhythmias. Further objectives will include number of therapeutic interventions of implanted devices, atrial fibrillation and heart failure biomarkers. CONCLUSION: The ERASe trial will be the first trial to test ertugliflozin in heart failure patients with nonpreserved ejection fraction and ongoing ICD ± CRT therapy regardless of their diabetic status. The ERASe trial may therefore extend the concept of SGLT2 inhibition to improve cardiac remodelling, including reduced arrhythmic burden. Trial registration Identifier EudraCT Nr. 2020-002581-14 / ClinicalTrials.gov Identifier: NCT04600921.

PRospective REgistry of PAtients in REfractory cardiogenic shock-The PREPARE CardShock registry.

AIM: Cardiogenic shock (CS) is a hemodynamically complex multisystem syndrome associated with persistently high morbidity and mortality. As CS is characterized by progressive failure to provide adequate systemic perfusion, supporting end-organ perfusion using mechanical circulatory support (MCS) seems intriguing. Since most patients with CS present in the catheterization laboratory, percutaneously implantable systems have the widest adoption in the field. We evaluated feasibility, outcomes, and complications after the introduction of a full-percutaneous program for both the Impella CP device and venoarterial extracorporeal membrane oxygenator (VA-ECMO). METHODS: PREPARE CardShock (PRospective REgistry of PAtients in REfractory cardiogenic shock) is a prospective single-center registry, including 248 consecutive patients between May 2019 and April 2021, who underwent cardiac catheterization and displayed advanced cardiogenic shock. The median age was 70 (58-77) years and 28% were female. Sixty-five percent of the cases had cardiac arrest, of which 66% were out-of-hospital cardiac arrest. A local standard operating procedure (SOP) indicating indications as well as relative and absolute contraindications for different means of MCS (Impella CP or VA-ECMO) was used to guide MCS use. The primary endpoint was in-hospital death and secondary endpoints were spontaneous myocardial infarction and major bleedings during the hospital stay. RESULTS: Overall mortality was 50.4% with a median survival of 2 (0-6) days. Significant independent predictors of mortality were cardiac arrest during the index event (odds ratio [OR] with 95% confidence interval [CI]: 2.53 [1.43-4.51]; p = 0.001), age > 65 years (OR: 2.05 [1.03-4.09]; p = 0.036]), pH < 7.30 (OR: 2.69 [1.56-4.66]; p < 0.001), and lactate levels > 2 mmol/L (OR: 4.51 [2.37-8.65]; p < 0.001). CONCLUSIONS: Conclusive SOPs assist target-orientated MCS use in CS. This study provides guidance on the implementation, validation, and modification of newly established MCS programs to aid centers that are establishing such programs.

Genetic Deficiency of TRAF5 Promotes Adipose Tissue Inflammation and Aggravates Diet-Induced Obesity in Mice.

Objective: The accumulation of inflammatory leukocytes is a prerequisite of adipose tissue inflammation during cardiometabolic disease. We previously reported that a genetic deficiency of the intracellular signaling adaptor TRAF5 (TNF [tumor necrosis factor] receptor-associated factor 5) accelerates atherosclerosis in mice by increasing inflammatory cell recruitment. Here, we tested the hypothesis that an impairment of TRAF5 signaling modulates adipose tissue inflammation and its metabolic complications in a model of diet-induced obesity in mice. Approach and Results: To induce diet-induced obesity and adipose tissue inflammation, wild-type or Traf5-/- mice consumed a high-fat diet for 18 weeks. Traf5-/- mice showed an increased weight gain, impaired insulin tolerance, and increased fasting blood glucose. Weight of livers and peripheral fat pads was increased in Traf5-/- mice, whereas lean tissue weight and growth were not affected. Flow cytometry of the stromal vascular fraction of visceral adipose tissue from Traf5-/- mice revealed an increase in cytotoxic T cells, CD11c+ macrophages, and increased gene expression of proinflammatory cytokines and chemokines. At the level of cell types, expression of TNF[alpha], MIP (macrophage inflammatory protein)-1[alpha], MCP (monocyte chemoattractant protein)-1, and RANTES (regulated on activation, normal T-cell expressed and secreted) was significantly upregulated in Traf5-deficient adipocytes but not in Traf5-deficient leukocytes from visceral adipose tissue. Finally, Traf5 expression was lower in adipocytes from obese patients and mice and recovered in adipose tissue of obese patients one year after bariatric surgery. Conclusions: We show that a genetic deficiency of TRAF5 in mice aggravates diet-induced obesity and its metabolic derangements by a proinflammatory response in adipocytes. Our data indicate that TRAF5 may promote anti-inflammatory and obesity-preventing signaling events in adipose tissue.

Pathogenic Autoimmunity in Atherosclerosis Evolves From Initially Protective Apolipoprotein B100-Reactive CD4+ T-Regulatory Cells.

BACKGROUND: Throughout the inflammatory response that accompanies atherosclerosis, autoreactive CD4+ T-helper cells accumulate in the atherosclerotic plaque. Apolipoprotein B100 (apoB), the core protein of low-density lipoprotein, is an autoantigen that drives the generation of pathogenic T-helper type 1 (TH1) cells with proinflammatory cytokine secretion. Clinical data suggest the existence of apoB-specific CD4+ T cells with an atheroprotective, regulatory T cell (Treg) phenotype in healthy individuals. Yet, the function of apoB-reactive Tregs and their relationship with pathogenic TH1 cells remain unknown. METHODS: To interrogate the function of autoreactive CD4+ T cells in atherosclerosis, we used a novel tetramer of major histocompatibility complex II to track T cells reactive to the mouse self-peptide apo B978-993 (apoB+) at the single-cell level. RESULTS: We found that apoB+ T cells build an oligoclonal population in lymph nodes of healthy mice that exhibit a Treg-like transcriptome, although only 21% of all apoB+ T cells expressed the Treg transcription factor FoxP3 (Forkhead Box P3) protein as detected by flow cytometry. In single-cell RNA sequencing, apoB+ T cells formed several clusters with mixed TH signatures that suggested overlapping multilineage phenotypes with pro- and anti-inflammatory transcripts of TH1, T helper cell type 2 (TH2), and T helper cell type 17 (TH17), and of follicular-helper T cells. ApoB+ T cells were increased in mice and humans with atherosclerosis and progressively converted into pathogenic TH1/TH17-like cells with proinflammatory properties and only a residual Treg transcriptome. Plaque T cells that expanded during progression of atherosclerosis consistently showed a mixed TH1/TH17 phenotype in single-cell RNA sequencing. In addition, we observed a loss of FoxP3 in a fraction of apoB+ Tregs in lineage tracing of hyperlipidemic Apoe-/- mice. In adoptive transfer experiments, converting apoB+ Tregs failed to protect from atherosclerosis. CONCLUSIONS: Our results demonstrate an unexpected mixed phenotype of apoB-reactive autoimmune T cells in atherosclerosis and suggest an initially protective autoimmune response against apoB with a progressive derangement in clinical disease. These findings identify apoB autoreactive Tregs as a novel cellular target in atherosclerosis.

Multiparameter Monitoring with a Wearable Cardioverter Defibrillator.

A wearable cardioverter-defibrillator (WCD) is a temporary treatment option for patients at high risk for sudden cardiac death (SCD) and for patients who are temporarily not candidates for an implantable cardioverter defibrillator (ICD). In addition, the need for telemedical concepts in the detection and treatment of heart failure (HF) and its arrhythmias is growing. The WCD has evolved from a shock device detecting malignant ventricular arrhythmias (VA) and treating them with shocks to a heart-failure-monitoring device that captures physical activity and cardioacoustic biomarkers as surrogate parameters for HF to help the treating physician surveil and guide the HF therapy of each individual patient. In addition to its important role in preventing SCD, the WCD could become an important tool in heart failure treatment by helping prevent HF events by detecting imminent decompensation via remote monitoring and monitoring therapy success.

Inhibition of macrophage proliferation dominates plaque regression in response to cholesterol lowering.

Statins induce plaque regression characterized by reduced macrophage content in humans, but the underlying mechanisms remain speculative. Studying the translational APOE*3-Leiden.CETP mouse model with a humanized lipoprotein metabolism, we find that systemic cholesterol lowering by oral atorvastatin or dietary restriction inhibits monocyte infiltration, and reverses macrophage accumulation in atherosclerotic plaques. Contrary to current believes, none of (1) reduced monocyte influx (studied by cell fate mapping in thorax-shielded irradiation bone marrow chimeras), (2) enhanced macrophage egress (studied by fluorescent bead labeling and transfer), or (3) atorvastatin accumulation in murine or human plaque (assessed by mass spectrometry) could adequately account for the observed loss in macrophage content in plaques that undergo phenotypic regression. Instead, suppression of local proliferation of macrophages dominates phenotypic plaque regression in response to cholesterol lowering: the lower the levels of serum LDL-cholesterol and lipid contents in murine aortic and human carotid artery plaques, the lower the rates of in situ macrophage proliferation. Our study identifies macrophage proliferation as the predominant turnover determinant and an attractive target for inducing plaque regression.

Nationwide outcomes of aortic valve replacement for pure aortic regurgitation in Germany 2008-2015.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is routinely used in patients with severe aortic stenosis at increased operative risk. Due to potential technical difficulties, TAVR is not recommended for pure aortic regurgitation (AR). Smaller studies reported its use in AR, but data from big registries are lacking. The present study analyzes the nationwide use of surgical aortic valve replacement (SAVR) and TAVR in patients with AR from 2008 until 2015. METHODS: We identified 138,237 cases of aortic valve replacement in Germany based on ICD and OPS codes. RESULTS: Of 13.2% SAVR-cases and 1.3% of TAVR cases were performed in AR. AR patients undergoing SAVR were younger with lower logistic EuroSCORE (stenosis: 6.1 ± 5.6; AR: 4.5 ± 4.9). Nevertheless, stroke rates, bleedings, prolonged mechanical ventilation, and in-hospital mortality were higher (mortality: stenosis 2.6%, AR: 4.7%). In the TAVR group, patients with AR were at higher operative risk (logistic EuroSCORE: transfemoral (TF)-TAVR: stenosis: 14.3 ± 10.4; AR: 17.3 ± 13.3. Transapical (TA)-TAVR: stenosis: 16.1 ± 11.4; AR: 15.7 ± 12.2). Stroke rates were lower, but bleedings and prolonged ventilation occurred more frequently after TF-TAVR in AR compared to stenosis. The mortality varied markedly (TF-TAVR: 15.2% in 2011; 2.8% in 2015; TA-TAVR: 17.7% in 2012 and 0% in 2014). CONCLUSION: TAVR is off-label used in AR in clinical practice. TAVR seems to be a safe option for AR with regard to in-hospital outcomes. However, further research evaluating long-term outcomes is required to establish the feasibility of TAVR in pure AR.

Predictors of survival in patients with acute coronary syndrome undergoing percutaneous coronary intervention of unprotected left main coronary artery stenosis.

OBJECTIVE: Aim of this study was to investigate predictors of survival in unstable patients with high SYNTAX-1-score. BACKGROUND: In significant unprotected left main coronary artery (ULMCA) stenosis, treatment options include percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG). While CABG is recommended for stable patients with ULMCA stenosis and a SYNTAX-1-score > 32, PCI may be preferable in unstable or high operative risk patients. METHODS: Retrospective single-center all-comers registry study. RESULTS: A total of 142 patients underwent ULMCA-PCI (~72.9 years, 23.2% females, 54.2% survival in 2-year follow-up), 84 of whom had a SYNTAX-1 > 32 (37.4 ± 12.8). Patients in the high-SYNTAX-1-group (score > 32) were more often in an acute condition compared to low-SYNTAX-2-group (score ≤ 32) including acute myocardial infarction (76.2% vs. 57.4%, p = .024), cardiogenic shock (48.2% vs. 14.8%, p = .001), or need for mechanical support (36.1% vs. 11.1%, p = .001). Survival was predicted by the acute condition including cardiogenic shock (OR 0.06 and 0.05) and myocardial infarction (OR 0.03 and 0.34) in both groups. Performance of the SYNTAX-1-score was limited in our patient collective in both groups (c-index 0.65 vs. 0.63) while SYNTAX-2-PCI-score performed better (c-index 0.67 vs. 0.67). EuroScore II had the best discriminative ability (c-index 0.87 vs. 0.78). CONCLUSIONS: The majority of patients undergoing ULMCA-PCI presented in acute conditions with high SYNTAX-1-score, and is therefore underrepresented in clinical trials. Prognosis was best predicted by the acute condition and the EuroScore II. These data suggest that therapy in unstable patients should be guided by clinical condition over the anatomical SYNTAX-1-score.

Novel Reversible Model of Atherosclerosis and Regression Using Oligonucleotide Regulation of the LDL Receptor.

RATIONALE: Animal models have been used to explore factors that regulate atherosclerosis. More recently, they have been used to study the factors that promote loss of macrophages and reduction in lesion size after lowering of plasma cholesterol levels. However, current animal models of atherosclerosis regression require challenging surgeries, time-consuming breeding strategies, and methods that block liver lipoprotein secretion. OBJECTIVE: We sought to develop a more direct or time-effective method to create and then reverse hypercholesterolemia and atherosclerosis via transient knockdown of the hepatic LDLR (low-density lipoprotein receptor) followed by its rapid restoration. METHODS AND RESULTS: We used antisense oligonucleotides directed to LDLR mRNA to create hypercholesterolemia in wild-type C57BL/6 mice fed an atherogenic diet. This led to the development of lesions in the aortic root, aortic arch, and brachiocephalic artery. Use of a sense oligonucleotide replicating the targeted sequence region of the LDLR mRNA rapidly reduced circulating cholesterol levels because of recovery of hepatic LDLR expression. This led to a decrease in macrophages within the aortic root plaques and brachiocephalic artery, that is, regression of inflammatory cell content, after a period of 2 to 3 weeks. CONCLUSIONS: We have developed an inducible and reversible hepatic LDLR knockdown mouse model of atherosclerosis regression. Although cholesterol reduction decreased early en face lesions in the aortic arches, macrophage area was reduced in both early and late lesions within the aortic sinus after reversal of hypercholesterolemia. Our model circumvents many of the challenges associated with current mouse models of regression. The use of this technology will potentially expedite studies of atherosclerosis and regression without use of mice with genetic defects in lipid metabolism.

Atlas of the Immune Cell Repertoire in Mouse Atherosclerosis Defined by Single-Cell RNA-Sequencing and Mass Cytometry.

RATIONALE: Atherosclerosis is a chronic inflammatory disease that is driven by the interplay of pro- and anti-inflammatory leukocytes in the aorta. Yet, the phenotypic and transcriptional diversity of aortic leukocytes is poorly understood. OBJECTIVE: We characterized leukocytes from healthy and atherosclerotic mouse aortas in-depth by single-cell RNA-sequencing and mass cytometry (cytometry by time of flight) to define an atlas of the immune cell landscape in atherosclerosis. METHODS AND RESULTS: Using single-cell RNA-sequencing of aortic leukocytes from chow diet- and Western diet-fed Apoe-/- and Ldlr-/- mice, we detected 11 principal leukocyte clusters with distinct phenotypic and spatial characteristics while the cellular repertoire in healthy aortas was less diverse. Gene set enrichment analysis on the single-cell level established that multiple pathways, such as for lipid metabolism, proliferation, and cytokine secretion, were confined to particular leukocyte clusters. Leukocyte populations were differentially regulated in atherosclerotic Apoe-/- and Ldlr-/- mice. We confirmed the phenotypic diversity of these clusters with a novel mass cytometry 35-marker panel with metal-labeled antibodies and conventional flow cytometry. Cell populations retrieved by these protein-based approaches were highly correlated to transcriptionally defined clusters. In an integrated screening strategy of single-cell RNA-sequencing, mass cytometry, and fluorescence-activated cell sorting, we detected 3 principal B-cell subsets with alterations in surface markers, functional pathways, and in vitro cytokine secretion. Leukocyte cluster gene signatures revealed leukocyte frequencies in 126 human plaques by a genetic deconvolution strategy. This approach revealed that human carotid plaques and microdissected mouse plaques were mostly populated by macrophages, T-cells, and monocytes. In addition, the frequency of genetically defined leukocyte populations in carotid plaques predicted cardiovascular events in patients. CONCLUSIONS: The definition of leukocyte diversity by high-dimensional analyses enables a fine-grained analysis of aortic leukocyte subsets, reveals new immunologic mechanisms and cell-type-specific pathways, and establishes a functional relevance for lesional leukocytes in human atherosclerosis.

Inflammatory Pathways Regulated by Tumor Necrosis Receptor-Associated Factor 1 Protect From Metabolic Consequences in Diet-Induced Obesity.

RATIONALE: The coincidence of inflammation and metabolic derangements in obese adipose tissue has sparked the concept of met-inflammation. Previous observations, however, suggest that inflammatory pathways may not ultimately cause dysmetabolism. OBJECTIVE: We have revisited the relationship between inflammation and metabolism by testing the role of TRAF (tumor necrosis receptor-associated factor)-1, an inhibitory adapter of inflammatory signaling of TNF (tumor necrosis factor)-α, IL (interleukin)-1ß, and TLRs (toll-like receptors). METHODS AND RESULTS: Mice deficient for TRAF-1, which is expressed in obese adipocytes and adipose tissue lymphocytes, caused an expected hyperinflammatory phenotype in adipose tissue with enhanced adipokine and chemokine expression, increased leukocyte accumulation, and potentiated proinflammatory signaling in macrophages and adipocytes in a mouse model of diet-induced obesity. Unexpectedly, TRAF-1-/- mice were protected from metabolic derangements and adipocyte growth, failed to gain weight, and showed improved insulin resistance-an effect caused by increased lipid breakdown in adipocytes and UCP (uncoupling protein)-1-enabled thermogenesis. TRAF-1-dependent catabolic and proinflammatory cues were synergistically driven by ß3-adrenergic and inflammatory signaling and required the presence of both TRAF-1-deficient adipocytes and macrophages. In human obesity, TRAF-1-dependent genes were upregulated. CONCLUSIONS: Enhancing TRAF-1-dependent inflammatory pathways in a gain-of-function approach protected from metabolic derangements in diet-induced obesity. These findings identify TRAF-1 as a regulator of dysmetabolism in mice and humans and question the pathogenic role of chronic inflammation in metabolism.

Impaired SIRT3 activity mediates cardiac dysfunction in endotoxemia by calpain-dependent disruption of ATP synthesis.

BACKGROUND: Sepsis-induced cardiomyopathy contributes to the high mortality of septic shock in critically ill patients. Since the underlying mechanisms are incompletely understood, we hypothesized that sepsis-induced impairment of sirtuin 3 (SIRT3) activity contributes to the development of septic cardiomyopathy. METHODS AND RESULTS: Treatment of mice with lipopolysaccharide (LPS) for 6 h resulted in myocardial NAD+ depletion and increased mitochondrial protein acetylation, indicating impaired myocardial SIRT3 activity due to NAD+ depletion. LPS treatment also resulted in impaired cardiac output in isolated working hearts, indicating endotoxemia-induced cardiomyopathy. Maintaining normal myocardial NAD+ levels in LPS-treated mice by Poly(ADP-ribose)polymerase 1 (PARP1) deletion prevented cardiac dysfunction, whereas additional SIRT3 deficiency blunted this beneficial effect, indicating that impaired SIRT3 activity contributes to cardiac dysfunction in endotoxemia. Measurements of mitochondrial ATP synthesis suggest that LPS-induced contractile dysfunction may result from cardiac energy depletion due to impaired SIRT3 activity. Pharmacological inhibition of mitochondrial calpains using MDL28170 normalized LPS-induced cleavage of the ATP5A1 subunit of ATP synthase and normalized contractile dysfunction, suggesting that cardiac energy depletion may result from calpain-mediated cleavage of ATP5A1. These beneficial effects were completely blunted by SIRT3 deficiency. Finally, a gene set enrichment analysis of hearts of patients with septic, ischemic or dilated cardiomyopathy revealed a sepsis-specific suppression of SIRT3 deacetylation targets, including ATP5A1, indicating a functional relevance of SIRT3-dependent pathways in human sepsis. CONCLUSIONS: Impaired SIRT3 activity may mediate cardiac dysfunction in endotoxemia by facilitating calpain-mediated disruption of ATP synthesis, suggesting SIRT3 activation as a potential therapeutic strategy to treat septic cardiomyopathy.

Tumor Necrosis Factor Receptor-Associated Factor 5 Promotes Arterial Neointima Formation through Smooth Muscle Cell Proliferation.

Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) are cytoplasmic adaptor proteins of the TNF/interleukin (IL)-1/Toll-like receptor superfamily. Ligands of this family such as TNFα, CD40L, and IL-1ß promote chronic inflammatory processes such as atherosclerosis and restenosis, the latter being a common adverse reaction after vascular interventions. We previously reported overexpression of TRAF5 in murine and human atheromata and TRAF5-dependent proinflammatory functions in vitro. However, the role of TRAF5 in restenosis remains unsettled. To evaluate whether TRAF5 affects neointima formation, TRAF5-/-LDLR-/- and TRAF5+/+LDLR-/- mice consuming a high cholesterol diet (HCD) received wire-induced injury of the carotid artery. After 28 days, TRAF5-deficient mice showed a 45% decrease in neointimal area formation compared with TRAF5-compentent mice. Furthermore, neointimal vascular smooth muscle cells (vSMC) and macrophages decreased whereas collagen increased in TRAF5-deficient mice. Mechanistically, the latter expressed lower transcript levels of the matrix metalloproteinases 2 and 9, both instrumental in extracellular matrix degradation and vSMC mobilization. Additionally, TRAF5-specific siRNA interference rendered murine vSMC less proliferative upon CD40L stimulation. In accordance with these findings, fewer vSMC isolated from TRAF5-deficient aortas were in a proliferative state as assessed by Ki67 and cyclin B1 expression. In conclusion, TRAF5 deficiency mitigates neointima formation in mice, likely through a TRAF5-dependent decrease in vSMC proliferation.

P2X7 Deficiency Blocks Lesional Inflammasome Activity and Ameliorates Atherosclerosis in Mice.

BACKGROUND: Extracellular adenosine triphosphate (ATP) binds as a danger signal to purinergic receptor P2X7 and promotes inflammasome assembly and interleukin-1ß expression. We hypothesized a functional role of the signal axis ATP-P2X7 in inflammasome activation and the chronic inflammation driving atherosclerosis. METHODS: P2X7-competent and P2X7-deficient macrophages were isolated and stimulated with lipopolysaccharide, ATP, or both. To assess whether P2X7 may have a role in atherosclerosis, P2X7 expression was analyzed in aortic arches from low density lipoprotein receptor-/- mice consuming a high-cholesterol or chow diet. P2X7+/+ and P2X7-/- low density lipoprotein receptor-/- mice were fed a high-cholesterol diet to investigate the functional role of P2X7 knockout in atherosclerosis. Human plaques were derived from carotid endarterectomy and stained against P2X7. RESULTS: Lipopolysaccharide or ATP stimulation alone did not activate caspase 1 in isolated macrophages. However, priming with lipopolysaccharide, followed by stimulation with ATP, led to an activation of caspase 1 and interleukin-1ß in P2X7-competent macrophages. In contrast, P2X7-deficient macrophages showed no activation of caspase 1 after sequential stimulation while still expressing a basal amount of interleukin-1ß. P2X7 receptor was higher expressed in murine atherosclerotic lesions, particularly by lesional macrophages. After 16 weeks of a high-cholesterol diet, P2X7-deficient mice showed smaller atherosclerotic lesions than P2X7-competent mice (0.162 cm2±0.023 [n=9], P2X7-/- low density lipoprotein receptor-/- : 0.084 cm2±0.01 [n=11], P=0.004) with a reduced amount of lesional macrophages. In accord with our in vitro findings, lesional caspase 1 activity was abolished in P2X7-/- mice. In addition, intravital microscopy revealed reduced leukocyte rolling and adhesion in P2X7-deficient mice. Last, we observe increased P2X7 expression in human atherosclerotic lesions, suggesting that our findings in mice are relevant for human disease. CONCLUSIONS: P2X7 deficiency resolved plaque inflammation by inhibition of lesional inflammasome activation and reduced experimental atherosclerosis. Therefore, P2X7 represents an interesting potential new target to combat atherosclerosis.

Purinergic receptor Y2 (P2Y2)- dependent VCAM-1 expression promotes immune cell infiltration in metabolic syndrome.

Sterile inflammation of visceral fat, provoked by dying adipocytes, links the metabolic syndrome to cardiovascular disease. Danger-associated molecular patterns, such as adenosine triphosphate (ATP), are released by activated or dying cells and orchestrate leukocyte infiltration and inflammation via the purinergic receptor P2Y2. The gene expression of ATP receptor P2Y2 did not change in several tissues in the course of obesity, but was increased within epididymal fat. Adipose tissue from P2Y 2-/- mice consuming high-fat diet (HFD) contained less crown-like structures with a reduced frequency of adipose tissue macrophages (ATMs). This was likely due to decreased leukocyte migration because of missing VCAM-1 exposition on P2Y2 deficient hypertrophic adipose tissue endothelial cells. Accordingly, P2Y 2-/- mice showed blunted traits of the metabolic syndrome: they gained less weight compared to P2Y 2+/+ controls, while intake of food and movement behaviour remained unchanged. Liver and adipose tissue were smaller in P2Y 2-/- animals. Insulin tolerance testing (ITT) performed in obese P2Y 2-/- mice revealed a better insulin sensitivity as well as lower plasma C-peptide and cholesterol levels. We demonstrate that interfering with somatic P2Y2 signalling prevents excessive immune cell deposition in diet-induced obesity (DIO), both attenuating adipose tissue inflammation and ameliorating the metabolic phenotype. Thus, blocking the P2Y2 cascade may be a promising strategy to limit metabolic disease and its sequelae.

Gene expression analysis to identify mechanisms underlying heart failure susceptibility in mice and humans.

Genetic factors are known to modulate cardiac susceptibility to ventricular hypertrophy and failure. To determine how strain influences the transcriptional response to pressure overload-induced heart failure (HF) and which of these changes accurately reflect the human disease, we analyzed the myocardial transcriptional profile of mouse strains with high (C57BL/6J) and low (129S1/SvImJ) susceptibility for HF development, which we compared to that of human failing hearts. Following transverse aortic constriction (TAC), C57BL/6J mice developed overt HF while 129S1/SvImJ did not. Despite a milder aortic constriction, impairment of ejection fraction and ventricular remodeling (dilation, fibrosis) was more pronounced in C57BL/6J mice. Similarly, changes in myocardial gene expression were more robust in C57BL/6J (461 genes) compared to 129S1/SvImJ mice (71 genes). When comparing these patterns to human dilated cardiomyopathy (1344 genes), C57BL/6J mice tightly grouped to human hearts. Overlay and bioinformatic analysis of the transcriptional profiles of C57BL/6J mice and human failing hearts identified six co-regulated genes (POSTN, CTGF, FN1, LOX, NOX4, TGFB2) with established link to HF development. Pathway enrichment analysis identified angiotensin and IGF-1 signaling as most enriched putative upstream regulator and pathway, respectively, shared between TAC-induced HF in C57BL/6J mice and in human failing hearts. TAC-induced heart failure in C57BL/6J mice more closely reflects the gene expression pattern of human dilated cardiomyopathy compared to 129S1/SvImJ mice. Unbiased as well as targeted gene expression and pathway analyses identified periostin, angiotensin signaling, and IGF-1 signaling as potential causes of increased HF susceptibility in C57BL/6J mice and as potentially useful drug targets for HF treatment.