ABSTRACT
NLRP3-inflammasome-driven inflammation is involved in the pathogenesis of a variety of diseases. Identification of endogenous inflammasome activators is essential for the development of new anti-inflammatory treatment strategies. Here, we identified that apolipoprotein C3 (ApoC3) activates the NLRP3 inflammasome in human monocytes by inducing an alternative NLRP3 inflammasome via caspase-8 and dimerization of Toll-like receptors 2 and 4. Alternative inflammasome activation in human monocytes is mediated by the Toll-like receptor adapter protein SCIMP. This triggers Lyn/Syk-dependent calcium entry and the production of reactive oxygen species, leading to activation of caspase-8. In humanized mouse models, ApoC3 activated human monocytes in vivo to impede endothelial regeneration and promote kidney injury in an NLRP3- and caspase-8-dependent manner. These data provide new insights into the regulation of the NLRP3 inflammasome and the pathophysiological role of triglyceride-rich lipoproteins containing ApoC3. Targeting ApoC3 might prevent organ damage and provide an anti-inflammatory treatment for vascular and kidney diseases.
Subject(s)
Acute Kidney Injury/immunology , Apolipoprotein C-III/immunology , Caspase 8/metabolism , Kidney Diseases/immunology , Monocytes/immunology , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Acute Kidney Injury/pathology , Adaptor Proteins, Signal Transducing , Animals , Apolipoprotein C-III/genetics , Cell Line , Disease Models, Animal , HEK293 Cells , Humans , Inflammasomes/immunology , Inflammation/genetics , Inflammation/immunology , Kidney Diseases/pathology , Membrane Proteins , Mice , Mice, Inbred C57BL , Mice, Inbred NOD , Mice, Knockout , Reactive Oxygen Species/metabolism , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/metabolismABSTRACT
BACKGROUND: Activation of the immune system contributes to cardiovascular diseases. The role of human-specific long noncoding RNAs in cardioimmunology is poorly understood. METHODS: Single-cell sequencing in peripheral blood mononuclear cells revealed a novel human-specific long noncoding RNA called HEAT4 (heart failure-associated transcript 4). HEAT4 expression was assessed in several in vitro and ex vivo models of immune cell activation, as well as in the blood of patients with heart failure (HF), acute myocardial infarction, or cardiogenic shock. The transcriptional regulation of HEAT4 was verified through cytokine treatment and single-cell sequencing. Loss-of-function and gain-of-function studies and multiple RNA-protein interaction assays uncovered a mechanistic role of HEAT4 in the monocyte anti-inflammatory gene program. HEAT4 expression and function was characterized in a vascular injury model in NOD.CB17-Prkdc scid/Rj mice. RESULTS: HEAT4 expression was increased in the blood of patients with HF, acute myocardial infarction, or cardiogenic shock. HEAT4 levels distinguished patients with HF from people without HF and predicted all-cause mortality in a cohort of patients with HF over 7 years of follow-up. Monocytes, particularly anti-inflammatory CD16+ monocytes, which are increased in patients with HF, are the primary source of HEAT4 expression in the blood. HEAT4 is transcriptionally activated by treatment with anti-inflammatory interleukin-10. HEAT4 activates anti-inflammatory and inhibits proinflammatory gene expression. Increased HEAT4 levels result in a shift toward more CD16+ monocytes. HEAT4 binds to S100A9, causing a monocyte subtype switch, thereby reducing inflammation. As a result, HEAT4 improves endothelial barrier integrity during inflammation and promotes vascular healing after injury in mice. CONCLUSIONS: These results characterize a novel endogenous anti-inflammatory pathway that involves the conversion of monocyte subtypes into anti-inflammatory CD16+ monocytes. The data identify a novel function for the class of long noncoding RNAs by preventing protein secretion and suggest long noncoding RNAs as potential targets for interventions in the field of cardioimmunology.
ABSTRACT
Lipodystrophy syndromes (LDs) are characterized by loss of adipose tissue, metabolic complications such as dyslipidemia, insulin resistance, and fatty liver disease, as well as accelerated atherosclerosis. As a result of adipose tissue deficiency, the systemic concentration of the adipokine leptin is reduced. A current promising therapeutic option for patients with LD is treatment with recombinant leptin (metreleptin), resulting in reduced risk of mortality. Here, we investigate the effects of leptin on endothelial to mesenchymal transition (EndMT), which impair the functional properties of endothelial cells and promotes atherogenesis in LD. Leptin treatment reduced inflammation and TGF-ß2-induced expression of mesenchymal genes and prevented impairment of endothelial barrier function. Treatment of lipodystrophic- and atherosclerosis-prone animals (Ldlr-/-; aP2-nSrebp1c-Tg) with leptin reduced macrophage accumulation in atherosclerotic lesions, vascular plaque protrusion, and the number of endothelial cells with mesenchymal gene expression, confirming a reduction in EndMT in LD after leptin treatment. Treatment with leptin inhibited LD-mediated induction of the proatherosclerotic cytokine growth/differentiation factor 15 (GDF15). Inhibition of GDF15 reduced EndMT induction triggered by plasma from patients with LD. Our study reveals that in addition to the effects on adipose tissue function, leptin treatment exerts beneficial effects protecting endothelial function and identity in LD by reducing GDF15.
Subject(s)
Endothelial Cells , Epithelial-Mesenchymal Transition , Growth Differentiation Factor 15 , Leptin , Lipodystrophy , Animals , Atherosclerosis/genetics , Endothelial Cells/drug effects , Epithelial-Mesenchymal Transition/drug effects , Growth Differentiation Factor 15/metabolism , Leptin/pharmacology , Leptin/therapeutic use , Lipodystrophy/drug therapy , Lipodystrophy/genetics , Mice , Transforming Growth Factor beta2/metabolismABSTRACT
PURPOSE OF REVIEW: Two large cardiovascular outcomes trials of monoclonal antibodies against proprotein convertase subtilisin/kexin type 9 (PCSK9) demonstrated that therapeutic inhibition of extracellular PCSK9 markedly reduces LDL cholesterol concentration and cardiovascular risk. Several novel strategies to inhibit PCSK9 function are in development. Different mechanisms of action may determine specific properties with potential relevance for patient care. RECENT FINDINGS: For the monoclonal antibodies evolocumab und alirocumab as first-generation PCSK9 inhibitors, follow-up data of up to 8âyears of exposure complement the information on efficacy and safety available from outcome trials. For the small-interfering RNA inclisiran as second-generation PCSK9 inhibitor, several phase III trials have been published and a cardiovascular outcome trial has completed recruitment and is ongoing. Third-generation PCSK9 inhibitors encompass, among others, orally available drugs such as MK-0616 and the fusion protein lerodalcibep. Additional strategies to inhibit PCSK9 include vaccination and gene editing. SUMMARY: Long-term inhibition of PCSK9 with monoclonal antibodies is safe and conveys sustained cardiovascular benefit. Novel strategies to inhibit PCSK9 function such as orally available drugs, RNA targeting, and one-time treatment with gene editing may further enhance the therapeutic armamentarium and enable novel preventive strategies.
Subject(s)
Antibodies, Monoclonal , PCSK9 Inhibitors , Proprotein Convertase 9 , Humans , Proprotein Convertase 9/metabolism , Proprotein Convertase 9/genetics , Proprotein Convertase 9/immunology , Antibodies, Monoclonal/therapeutic use , Animals , Cardiovascular Diseases/prevention & control , Cardiovascular Diseases/drug therapyABSTRACT
PURPOSE OF REVIEW: Monoclonal antibodies (mAb) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) have been established in cardiovascular risk prevention. The purpose of this review is to summarize the effects of PCSK9 inhibitors across different patient populations. RECENT FINDINGS: Long-term data on the use of evolocumab and alirocumab shows persisting low- density lipoprotein cholesterol (LDL-C) lowering and good tolerability. PCSK9 inhibitors are effective and safe in both sexes, in pediatric patients as well as in the elderly. Initiation of PCSK9 mAb during acute myocardial infarction is safe and leads to beneficial morphological plaque changes. The PCSK9 inhibitors evolocumab, alirocumab and inclisiran lower LDL-C in patients with heterozygous familial hypercholesterolemia (FH), while the response of patients with homozygous FH is heterogeneous. New areas of application beyond lipid lowering are currently investigated. SUMMARY: PCSK9 inhibitors are safe, well tolerated, and effective in primary and secondary prevention in a wide range of patient populations.
Subject(s)
PCSK9 Inhibitors , Humans , Proprotein Convertase 9/metabolism , Proprotein Convertase 9/genetics , Proprotein Convertase 9/immunology , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal/adverse effects , Cholesterol, LDL/blood , Anticholesteremic Agents/therapeutic use , Anticholesteremic Agents/adverse effectsABSTRACT
BACKGROUND: Cardiogenic shock (CS) is characterized by impaired cardiac function, very high mortality, and limited treatment options. The pro-inflammatory signalling during different phases of CS is incompletely understood. METHODS: We collected serum and plasma (N=44) as well as freshly isolated peripheral blood mononuclear cells (PBMC, N=7) of patients with CS complicating acute myocardial infarction on admission and after revascularization (24h, 48h, 72h) and of healthy controls (serum and plasma N=75; PBMC N=12). RESULTS: PBMC of CS patients had increased gene expression of NLRP3, CASP1, PYCARD, IL1B, and IL18 and showed increased rates of pyroptosis (control: 4.7±0.3% vs. 9.9±1.7% in CS patients, p=0.02). Serum interleukin (IL)-1ß levels were increased after revascularization. IL-18 and IL-6 were higher in patients with CS than in healthy controls but comparable before and after revascularization. Pro-inflammatory apoptosis-associated speck-like proteins containing CARD (ASC) specks were elevated in the serum of CS patients on admission and increased after revascularization (admission: 11.1±4.4 specks/µl, after 24h: 19.0±3.9, p=0.02). ASC specks showed a significant association with 30-day mortality in patients with CS (p<0.05). The estimated regression coefficients and odds ratios indicated a positive relationship between ASC specks and mortality (Odds ratio 1.029, 95% CI, 1.000 to 1.072; p=0.02). CONCLUSIONS: Pyroptosis and circulating ASC specks are increased in patients with CS and are particularly induced after reperfusion This underscores their potential role as a biomarker for poor outcomes in CS patients. ASC specks represent promising new therapeutic targets for CS patients with high inflammatory burden.
ABSTRACT
BACKGROUND: Obicetrapib, a novel, selective cholesteryl ester transfer protein (CETP) inhibitor, reduces low-density lipoprotein cholesterol (LDL-C), LDL particles, apolipoprotein (Apo) B, and lipoprotein(a) [Lp(a)] and increases high-density lipoprotein cholesterol (HDL-C) when added to statins with or without ezetimibe. By substantially reducing LDL-C, obicetrapib has the potential to lower atherogenic lipoproteins in patients with atherosclerotic cardiovascular disease (ASCVD) or heterozygous familial hypercholesterolemia (HeFH) whose LDL-C levels remain high despite treatment with available maximally tolerated lipid-modifying therapies, addressing an unmet medical need in a patient population at high risk for cardiovascular events. METHODS AND RESULTS: BROADWAY (NCT05142722) and BROOKLYN (NCT05425745) are ongoing placebo-controlled, double-blind, randomized Phase III trials designed to examine the efficacy, safety, and tolerability of obicetrapib as an adjunct to dietary intervention and maximally tolerated lipid-modifying therapies in participants with a history of ASCVD and/or underlying HeFH whose LDL-C is not adequately controlled. The primary efficacy endpoint was the percent change in LDL-C from baseline to day 84. Other endpoints included changes in Apo B, non-HDL-C, HDL-C, Apo A1, Lp(a), and triglycerides in addition to parameters evaluating safety, tolerability, and pharmacokinetics. BROADWAY also included an adjudicated assessment of major adverse cardiovascular events, measurements of glucose homeostasis, and an ambulatory blood pressure monitoring substudy. A total of 2,532 participants were randomized in BROADWAY and 354 in BROOKLYN to receive obicetrapib 10 mg or placebo (2:1) for 365 days with follow-up through 35 days after the last dose. Results from both trials are anticipated in 2024. CONCLUSION: These trials will provide safety and efficacy data to support the potential use of obicetrapib among patients with ASCVD or HeFH with elevated LDL-C for whom existing therapies are not sufficiently effective or well-tolerated.
Subject(s)
Anticholesteremic Agents , Atherosclerosis , Cholesterol, LDL , Humans , Atherosclerosis/drug therapy , Atherosclerosis/prevention & control , Anticholesteremic Agents/therapeutic use , Anticholesteremic Agents/administration & dosage , Double-Blind Method , Cholesterol, LDL/blood , Male , Female , Cholesterol Ester Transfer Proteins/antagonists & inhibitors , Cholesterol, HDL/blood , Hyperlipoproteinemia Type II/drug therapy , Hyperlipoproteinemia Type II/blood , Hyperlipoproteinemia Type II/complications , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Lipoprotein(a)/blood , Middle AgedABSTRACT
BACKGROUND: Lipoprotein(a) (Lp(a)) is an inherited risk factor for atherosclerotic cardiovascular disease (ASCVD). Limited data exist on Lp(a) values in children. We aimed to evaluate whether Lp(a) concentrations in youth are influenced by BMI. METHODS: 756 blood samples of 248 children with obesity and 264 matched healthy children aged 5 and 18 years, enrolled in the population-based LIFE Child (German civilization diseases cohort) study, were analyzed. Repeat measurements were available in 154 children (1-4 follow ups, ~1 year apart). RESULTS: The median Lp(a) concentration in the total cohort (n = 512) at first visit was 9.7 mg/dL (IQR 4.0-28.3). Lp(a) concentrations between 30-50 mg/dL were observed in 11.5%, while 12.5% exhibited Lp(a) â§50 mg/dL. There was no association of Lp(a) with body mass index (BMI) (ß = 0.004, P = 0.49). Lp(a) levels did not correlate with age or sex, while Lp(a) was associated positively with low-density lipoprotein cholesterol (ß = 0.05, P < 0.0001). The Lp(a) risk category remained stable in 94% of all children in repeated measurements. CONCLUSIONS: The data showed no association of Lp(a) levels in children with BMI, age or sex. Measurement of Lp(a) in youth may be useful to identify children at increased lifetime risk for ASCVD. IMPACT: In youth, Lp(a) levels are not affected by age, sex and BMI. Lp(a) risk categories remain stable over time in repeated measurements in children. Measurement of Lp(a) in children may be useful as an additional factor to identify children at increased lifetime risk for ASCVD and for reverse family screening.
Subject(s)
Body Mass Index , Lipoprotein(a) , Humans , Child , Lipoprotein(a)/blood , Female , Male , Adolescent , Child, Preschool , Age Factors , Sex Factors , Risk Factors , Case-Control Studies , Cholesterol, LDL/blood , GermanyABSTRACT
BACKGROUND: Atrial fibrillation (AF) is one of the most frequent causes of stroke. Several randomized trials have shown that prolonged monitoring increases the detection of AF, but the effect on reducing recurrent cardioembolism, ie, ischemic stroke and systemic embolism, remains unknown. We aim to evaluate whether a risk-adapted, intensified heart rhythm monitoring with consequent guideline conform treatment, which implies initiation of oral anticoagulation (OAC), leads to a reduction of recurrent cardioembolism. METHODS: Find-AF 2 is a randomized, controlled, open-label parallel multicenter trial with blinded endpoint assessment. 5,200 patients ≥ 60 years of age with symptomatic ischemic stroke within the last 30 days and without known AF will be included at 52 study centers with a specialized stroke unit in Germany. Patients without AF in an additional 24-hour Holter ECG after the qualifying event will be randomized in a 1:1 fashion to either enhanced, prolonged and intensified ECG-monitoring (intervention arm) or standard of care monitoring (control arm). In the intervention arm, patients with a high risk of underlying AF will receive continuous rhythm monitoring using an implantable cardiac monitor (ICM) whereas those without high risk of underlying AF will receive repeated 7-day Holter ECGs. The duration of rhythm monitoring within the control arm is up to the discretion of the participating centers and is allowed for up to 7 days. Patients will be followed for at least 24 months. The primary efficacy endpoint is the time until recurrent ischemic stroke or systemic embolism occur. CONCLUSIONS: The Find-AF 2 trial aims to demonstrate that enhanced, prolonged and intensified rhythm monitoring results in a more effective prevention of recurrent ischemic stroke and systemic embolism compared to usual care.
Subject(s)
Atrial Fibrillation , Embolism , Ischemic Stroke , Stroke , Humans , Infant , Atrial Fibrillation/complications , Atrial Fibrillation/diagnosis , Furylfuramide , Prospective Studies , Stroke/etiology , Stroke/prevention & control , Stroke/diagnosis , Electrocardiography, Ambulatory/methods , Embolism/diagnosis , Embolism/etiology , Embolism/prevention & controlABSTRACT
BACKGROUND: Quantitative flow ratio (QFR) is a novel, software-based method to evaluate the physiology of coronary lesions. The aim of this study was to compare QFR with the established invasive measurements of coronary blood flow using instantaneous wave-free ratio (iFR) or resting full-cycle ratio (RFR) in daily cathlab routine. METHODS: 102 patients with stable coronary artery disease and a coronary stenosis of 40%-90% were simultaneously assessed with QFR and iFR or RFR. QFR-computation was performed by two certified experts using the appropriate software (QAngio XA 3D 3.2). RESULTS: QFR showed a significant correlation (r = 0.75, p < 0.001) to iFR and RFR. The area under the receiver curve for all measurements was 0.93 (95% confidence interval, 0.87-0.98) for QFR compared to iFR or RFR. QFR based assessment required less time with a median of 501 s (IQR 421-659 s) compared to iFR or RFR which required a median of 734 s to obtain the result (IQR 512-967 s; p < 0.001). The median use of contrast medium was similar with 21 mL (IQR 16-30 mL) for the QFR-based and 22 mL (IQR 15-35 mL) for the iFR- or RFR-based diagnostic. QFR diagnostic required less radiation. The median dose area product for QFR was 307cGycm2 (IQR 151-429 cGycm2 ) compared to 599 cGycm2 (IQR 345-1082 cGycm2 ) for iFR or RFR, p < 0.001. CONCLUSION: QFR measurements of coronary artery blood flow correlate with iFR or RFR measurements and are associated with shorter procedure times and reduced radiation dose.
Subject(s)
Coronary Artery Disease , Coronary Stenosis , Fractional Flow Reserve, Myocardial , Humans , Coronary Angiography/methods , Predictive Value of Tests , Treatment Outcome , Coronary Artery Disease/diagnostic imaging , Coronary Stenosis/diagnostic imaging , Cardiac Catheterization , Coronary Vessels/diagnostic imaging , Severity of Illness IndexABSTRACT
OBJECTIVES: Upper reference limits of high-sensitivity cardiac troponin T (hs-cTnT) are derived from healthy, population-based cohorts, and are frequently exceeded in hospitalized patients. In this study we aim to systematically examine the differences between in-hospital patients with no diagnosed cardiac diseases and a population-based cohort. METHODS: Retrospective analyses were performed in two independent cohorts. We included 5,652 participants of the prospective population-based LIFE cohort as well as 9,300 patients having been treated at our hospital between 2014 and 2021. In both cohorts, subjects with diagnosed or suspected cardiac diseases were excluded. We used Spearman's rank correlation for correlation analyses of hs-cTnT serum concentrations and age. Sex- and age-adjusted 99th percentiles for hs-cTnT in subjects with preserved renal function were obtained in both cohorts. RESULTS: In both cohorts, hs-cTnT serum concentrations positively correlated with age. Male sex was associated with higher hs-cTnT serum concentrations. Persons treated in hospital showed significantly higher hs-cTnT concentrations in females and males aged above 50. While in the population-based cohort only 99th percentile hs-cTnT results of females aged above 70 and males aged above 60â¯years exceeded the assay's upper reference limit, the 99th percentiles of in-hospital females over 40â¯years and males of all age groups exceeded this threshold. CONCLUSIONS: Besides age and sex, hospitalization per se is correlated with higher serum concentrations of hs-cTnT in most age groups. Our results indicate, that unconditionally applying current hs-cTnT cut-offs to inpatients might overestimate myocardial infarction and potentially lead to overdiagnosis.
Subject(s)
Myocardial Infarction , Troponin T , Female , Humans , Male , Retrospective Studies , Prospective Studies , Inpatients , Myocardial Infarction/diagnosis , BiomarkersABSTRACT
Cardiovascular diseases are the most frequent cause of disability and death. Evidence-based pharmacotherapy is the basis for successful treatment of common diseases, such as hypertension, heart failure, coronary artery disease, and atrial fibrillation. The proportion of older people with several diseases (multimorbidity) who need five or more drugs daily (polypharmacy) is steadily increasing. Evidence on the efficacy and safety of drugs in these patients is, however, limited because they are often excluded or underrepresented in clinical trials. In addition, clinical guidelines mostly focus on single diseases and only occasionally deal with the challenges in the pharmacotherapy of older multimorbid patients with polypharmacy. This article describes the options and special features of pharmacotherapy for hypertension, chronic heart failure and dyslipidemia, as well as antithrombotic treatment in (very) old people.
Subject(s)
Atrial Fibrillation , Heart Failure , Hypertension , Humans , Aged , Hypertension/drug therapy , Polypharmacy , Heart Failure/drug therapy , Multimorbidity , Atrial Fibrillation/drug therapyABSTRACT
BACKGROUND: Cardiovascular diseases and chronic kidney disease (CKD) are highly prevalent, aggravate each other, and account for substantial mortality. Both conditions are characterized by activation of the innate immune system. The alarmin interleukin-1α (IL-1α) is expressed in a variety of cell types promoting (sterile) systemic inflammation. The aim of the present study was to examine the role of IL-1α in mediating inflammation in the setting of acute myocardial infarction (AMI) and CKD. METHODS: We assessed the expression of IL-1α on the surface of monocytes from patients with AMI and patients with CKD and determined its association with atherosclerotic cardiovascular disease events during follow-up in an explorative clinical study. Furthermore, we assessed the inflammatory effects of IL-1α in several organ injury models in Il1a-/- and Il1b-/- mice and investigated the underlying mechanisms in vitro in monocytes and endothelial cells. RESULTS: IL-1α is strongly expressed on the surface of monocytes from patients with AMI and CKD compared with healthy controls. Higher IL-1α surface expression on monocytes from patients with AMI and CKD was associated with a higher risk for atherosclerotic cardiovascular disease events, which underlines the clinical relevance of IL-1α. In mice, IL-1α, but not IL-1ß, mediates leukocyte-endothelial adhesion as determined by intravital microscopy. IL-1α promotes accumulation of macrophages and neutrophils in inflamed tissue in vivo. Furthermore, IL-1α on monocytes stimulates their homing at sites of vascular injury. A variety of stimuli such as free fatty acids or oxalate crystals induce IL-1α surface expression and release by monocytes, which then mediates their adhesion to the endothelium via IL-1 receptor-1. IL-1α also promotes expression of the VCAM-1 (vascular cell adhesion molecule-1) on endothelial cells, thereby fostering the adhesion of circulating leukocytes. IL-1α induces inflammatory injury after experimental AMI, and abrogation of IL-1α prevents the development of CKD in oxalate or adenine-fed mice. CONCLUSIONS: IL-1α represents a key mediator of leukocyte-endothelial adhesion and inflammation in AMI and CKD. Inhibition of IL-1α may serve as a novel anti-inflammatory treatment strategy.
Subject(s)
Cell Adhesion/physiology , Endothelial Cells/metabolism , Interleukin-1alpha/metabolism , Myocardial Infarction/drug therapy , Renal Insufficiency, Chronic/drug therapy , Animals , Cell Adhesion/drug effects , Endothelium/metabolism , Humans , Inflammation/drug therapy , Inflammation/metabolism , Interleukin-1alpha/pharmacology , Mice , Monocytes/metabolism , Myocardial Infarction/metabolism , Neutrophils/metabolism , Renal Insufficiency, Chronic/metabolism , Vascular Cell Adhesion Molecule-1/metabolismABSTRACT
BACKGROUND: Barth syndrome (BTHS) is caused by mutations of the gene encoding tafazzin, which catalyzes maturation of mitochondrial cardiolipin and often manifests with systolic dysfunction during early infancy. Beyond the first months of life, BTHS cardiomyopathy typically transitions to a phenotype of diastolic dysfunction with preserved ejection fraction, blunted contractile reserve during exercise, and arrhythmic vulnerability. Previous studies traced BTHS cardiomyopathy to mitochondrial formation of reactive oxygen species (ROS). Because mitochondrial function and ROS formation are regulated by excitation-contraction coupling, integrated analysis of mechano-energetic coupling is required to delineate the pathomechanisms of BTHS cardiomyopathy. METHODS: We analyzed cardiac function and structure in a mouse model with global knockdown of tafazzin (Taz-KD) compared with wild-type littermates. Respiratory chain assembly and function, ROS emission, and Ca2+ uptake were determined in isolated mitochondria. Excitation-contraction coupling was integrated with mitochondrial redox state, ROS, and Ca2+ uptake in isolated, unloaded or preloaded cardiac myocytes, and cardiac hemodynamics analyzed in vivo. RESULTS: Taz-KD mice develop heart failure with preserved ejection fraction (>50%) and age-dependent progression of diastolic dysfunction in the absence of fibrosis. Increased myofilament Ca2+ affinity and slowed cross-bridge cycling caused diastolic dysfunction, in part, compensated by accelerated diastolic Ca2+ decay through preactivated sarcoplasmic reticulum Ca2+-ATPase. Taz deficiency provoked heart-specific loss of mitochondrial Ca2+ uniporter protein that prevented Ca2+-induced activation of the Krebs cycle during ß-adrenergic stimulation, oxidizing pyridine nucleotides and triggering arrhythmias in cardiac myocytes. In vivo, Taz-KD mice displayed prolonged QRS duration as a substrate for arrhythmias, and a lack of inotropic response to ß-adrenergic stimulation. Cellular arrhythmias and QRS prolongation, but not the defective inotropic reserve, were restored by inhibiting Ca2+ export through the mitochondrial Na+/Ca2+ exchanger. All alterations occurred in the absence of excess mitochondrial ROS in vitro or in vivo. CONCLUSIONS: Downregulation of mitochondrial Ca2+ uniporter, increased myofilament Ca2+ affinity, and preactivated sarcoplasmic reticulum Ca2+-ATPase provoke mechano-energetic uncoupling that explains diastolic dysfunction and the lack of inotropic reserve in BTHS cardiomyopathy. Furthermore, defective mitochondrial Ca2+ uptake provides a trigger and a substrate for ventricular arrhythmias. These insights can guide the ongoing search for a cure of this orphaned disease.
Subject(s)
Arrhythmias, Cardiac/diagnosis , Arrhythmias, Cardiac/etiology , Barth Syndrome/complications , Barth Syndrome/genetics , Calcium Channels/deficiency , Myocardial Contraction/genetics , Adenosine Triphosphate/biosynthesis , Animals , Barth Syndrome/metabolism , Biomarkers , Brain/metabolism , Calcium/metabolism , Diastole , Disease Models, Animal , Disease Susceptibility , Excitation Contraction Coupling/genetics , Heart Function Tests , Humans , Mice , Mice, Knockout , Mitochondria, Heart/genetics , Mitochondria, Heart/metabolism , Muscle, Skeletal/metabolism , Myocytes, Cardiac/metabolism , NADP/metabolism , Oxidation-Reduction , Reactive Oxygen Species/metabolism , Stroke Volume , SystoleABSTRACT
BACKGROUND: Elevated triglyceride and glucose levels are associated with an increased cardiovascular disease risk including ischemic stroke. It is not known whether the response to a combined oral triglyceride and glucose challenge after ischemic stroke improves identification of patients with increased risk for recurrent vascular events. METHODS: The prospective, observational Berlin "Cream&Sugar" study was conducted at 3 different university hospital sites of the Charité-Universitätsmedizin Berlin, Germany, between January 24, 2009 and July 31, 2017. Patients with first-ever ischemic stroke were recruited 3 to 7 days after stroke. An oral triglyceride tolerance test (OTTT) and consecutive blood tests before (t0) as well as 3 (t1), 4 (t2), and 5 hours (t3) after OTTT were performed in fasting patients. An oral glucose tolerance test was performed in all nondiabetic patients 3 hours after the start of OTTT. Outcomes of the study were recurrent fatal or nonfatal stroke as well as a composite vascular end point including stroke, transient ischemic attack, myocardial infarction, coronary revascularization, and cardiovascular death assessed 1 year after stroke. Cox regression models were used to estimate hazard ratios and corresponding 95% CIs between patients with high versus low levels of triglyceride and glucose levels. RESULTS: Overall 755 patients were included; 523 patients completed OTTT and 1-year follow-up. Patients were largely minor strokes patients with a median National Institutes of Health Stroke Scale score of 1 (0-3). Comparing highest versus lowest quartiles of triglyceride levels, neither fasting (adjusted hazard ratiot0, 1.24 [95% CI, 0.45-3.42]) nor postprandial triglyceride levels (adjusted hazard ratiot3, 0.44 [95% CI, 0.16-1.25]) were associated with recurrent stroke. With regard to recurrent vascular events, results were similar for fasting triglycerides (adjusted hazard ratiot0, 1.09 [95% CI, 0.49-2.43]), however, higher postprandial triglyceride levels were significantly associated with a lower risk for recurrent vascular events (adjusted hazard ratiot3, 0.42 [95% CI, 0.18-0.95]). No associations were observed between fasting and post-oral glucose tolerance test blood glucose levels and recurrent vascular risk. All findings were irrespective of the diabetic status of patients. CONCLUSIONS: In this cohort of patients with first-ever' minor ischemic stroke, fasting triglyceride or glucose levels were not associated with recurrent stroke at one year after stroke. However, higher postprandial triglyceride levels were associated with a lower risk of recurrent vascular events which requires further validation in future studies. Overall, our results do not support the routine use of a combined OTTT/oral glucose tolerance test to improve risk prediction for recurrent stroke.
Subject(s)
Ischemic Attack, Transient , Ischemic Stroke , Stroke , Berlin/epidemiology , Glucose , Glucose Tolerance Test , Humans , Ischemic Attack, Transient/complications , Prospective Studies , Risk Factors , Stroke/diagnosis , Stroke/epidemiology , Sugars , TriglyceridesABSTRACT
Alterations of RNA editing that affect the secondary structure of RNAs can cause human diseases. We therefore studied RNA editing in failing human hearts. Transcriptome sequencing showed that adenosine-to-inosine (A-to-I) RNA editing was responsible for 80% of the editing events in the myocardium. Failing human hearts were characterized by reduced RNA editing. This was primarily attributable to Alu elements in introns of protein-coding genes. In the failing left ventricle, 166 circRNAs were upregulated and 7 circRNAs were downregulated compared to non-failing controls. Most of the upregulated circRNAs were associated with reduced RNA editing in the host gene. ADAR2, which binds to RNA regions that are edited from A-to-I, was decreased in failing human hearts. In vitro, reduction of ADAR2 increased circRNA levels suggesting a causal effect of reduced ADAR2 levels on increased circRNAs in the failing human heart. To gain mechanistic insight, one of the identified upregulated circRNAs with a high reduction of editing in heart failure, AKAP13, was further characterized. ADAR2 reduced the formation of double-stranded structures in AKAP13 pre-mRNA, thereby reducing the stability of Alu elements and the circularization of the resulting circRNA. Overexpression of circAKAP13 impaired the sarcomere regularity of human induced pluripotent stem cell-derived cardiomyocytes. These data show that ADAR2 mediates A-to-I RNA editing in the human heart. A-to-I RNA editing represses the formation of dsRNA structures of Alu elements favoring canonical linear mRNA splicing and inhibiting the formation of circRNAs. The findings are relevant to diseases with reduced RNA editing and increased circRNA levels and provide insights into the human-specific regulation of circRNA formation.
Subject(s)
Induced Pluripotent Stem Cells , RNA Editing , Humans , Induced Pluripotent Stem Cells/metabolism , RNA/chemistry , RNA/genetics , RNA/metabolism , RNA, Circular/genetics , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolismABSTRACT
BACKGROUND: Guidelines recommend physical activity to reduce cardiovascular (CV) events. The association between physical activity and progression of chronic kidney disease (CKD) with and without diabetes is unknown. We assessed the association of self-reported physical activity with renal and CV outcomes in high-risk patients aged ≥ 55 years over a median follow-up of 56 months in post-hoc analysis of a previously randomized trial program. METHODS: Analyses were done with Cox regression analysis, mixed models for repeated measures, ANOVA and χ2-test. 31,312 patients, among them 19,664 with and 11,648 without diabetes were analyzed. RESULTS: Physical activity was inversely associated with renal outcomes (doubling of creatinine, end-stage kidney disease (ESRD)) and CV outcomes (CV death, myocardial infarction, stroke, heart failure hospitalization). Moderate activity (at least 2 times/week to every day) was associated with lower risk of renal outcomes and lower incidence of new albuminuria (p < 0.0001 for both) compared to lower exercise levels. Similar results were observed for those with and without diabetes without interaction for renal outcomes (p = 0.097-0.27). Physical activity was associated with reduced eGFR decline with a moderate association between activity and diabetes status (p = 0.05). CONCLUSIONS: Moderate physical activity was associated with improved kidney outcomes with a threshold at two sessions per week. The association of physical activity with renal outcomes did not meaningfully differ with or without diabetes but absolute benefit of activity was even greater in people with diabetes. Thus, risks were similar between those with diabetes undertaking high physical activity and those without diabetes but low physical activity. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov.uniqueidentifier :NCT00153101.
Subject(s)
Cardiovascular Diseases/prevention & control , Diabetes Mellitus/therapy , Diabetic Nephropathies/therapy , Exercise , Healthy Lifestyle , Kidney Failure, Chronic/prevention & control , Renal Insufficiency, Chronic/therapy , Risk Reduction Behavior , Aged , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/mortality , Cardiovascular Diseases/physiopathology , Databases, Factual , Diabetes Mellitus/diagnosis , Diabetes Mellitus/mortality , Diabetes Mellitus/physiopathology , Diabetic Nephropathies/diagnosis , Diabetic Nephropathies/mortality , Diabetic Nephropathies/physiopathology , Female , Glomerular Filtration Rate , Heart Disease Risk Factors , Humans , Kidney/physiopathology , Kidney Failure, Chronic/diagnosis , Kidney Failure, Chronic/mortality , Kidney Failure, Chronic/physiopathology , Male , Middle Aged , Protective Factors , Randomized Controlled Trials as Topic , Renal Insufficiency, Chronic/diagnosis , Renal Insufficiency, Chronic/mortality , Renal Insufficiency, Chronic/physiopathology , Risk Assessment , Time Factors , Treatment OutcomeABSTRACT
AIM: To evaluate the effect of bempedoic acid on glycaemic and lipid variables in patients with hypercholesterolaemia. METHODS: A patient-level pooled analysis of four phase 3, randomized, double-blind, placebo-controlled trials evaluated changes in glycaemia, change from baseline in LDL-C, and adverse events. Patients (N = 3621) on maximally tolerated statins were randomized 2:1 to oral bempedoic acid 180 mg or placebo once daily for 12 to 52 weeks with the results analysed by baseline glycaemic status (diabetes, prediabetes, or normoglycaemia). RESULTS: The annual rate of new-onset diabetes for bempedoic acid versus placebo in patients with normoglycaemia at baseline (n = 618) was 0.3% versus 0.8%, and for patients with prediabetes at baseline (n = 1868) it was 4.7% versus 5.9%. In patients with diabetes or prediabetes, bempedoic acid significantly (P < .0001) reduced HbA1c by -0.12% and -0.06%, respectively, and did not worsen fasting glucose versus placebo. Bempedoic acid significantly and consistently lowered LDL-C levels versus placebo, regardless of baseline glycaemic status (placebo-corrected difference range, -17.2% to -29.6%; P < .001 for each stratum). The safety of bempedoic acid was comparable with placebo and similar across glycaemic strata. CONCLUSIONS: Bempedoic acid significantly lowered LDL-C across glycaemic strata and did not worsen glycaemic variables or increase the incidence of new-onset diabetes versus placebo over a median follow-up of 1 year.
Subject(s)
Diabetes Mellitus, Type 2 , Prediabetic State , Cholesterol, LDL , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Dicarboxylic Acids , Double-Blind Method , Fatty Acids , Glycemic Control , Humans , Prediabetic State/complications , Prediabetic State/drug therapy , Treatment OutcomeABSTRACT
BACKGROUND AND PURPOSE: Impaired kidney function is associated with an increased risk of vascular events in acute stroke patients, when assessed by single measurements of estimated glomerular filtration rate (eGFR). It is unknown whether repeated measurements provide additional information for risk prediction. METHODS: The MonDAFIS (Systematic Monitoring for Detection of Atrial Fibrillation in Patients with Acute Ischemic Stroke) study randomly assigned 3465 acute ischemic stroke patients to either standard procedures or an additive Holter electrocardiogram. Baseline eGFR (CKD-EPI formula) were dichotomized into values of < versus ≥60 ml/min/1.73 m2 . eGFR dynamics were classified based on two in-hospital values as "stable normal" (≥60 ml/min/1.73 m2 ), "increasing" (by at least 15% from baseline, second value ≥ 60 ml/min/1.73 m2 ), "decreasing" (by at least 15% from baseline of ≥60 ml/min/1.73 m2 ), and "stable decreased" (<60 ml/min/1.73 m2 ). The composite endpoint (stroke, major bleeding, myocardial infarction, all-cause death) was assessed after 24 months. We estimated hazard ratios in confounder-adjusted models. RESULTS: Estimated glomerular filtration rate at baseline was available in 2947 and a second value in 1623 patients. After adjusting for age, stroke severity, cardiovascular risk factors, and randomization, eGFR < 60 ml/min/1.73 m2 at baseline (hazard ratio [HR] = 2.2, 95% confidence interval [CI] = 1.40-3.54) as well as decreasing (HR = 1.79, 95% CI = 1.07-2.99) and stable decreased eGFR (HR = 1.64, 95% CI = 1.20-2.24) were independently associated with the composite endpoint. In addition, eGFR < 60 ml/min/1.732 at baseline (HR = 3.02, 95% CI = 1.51-6.10) and decreasing eGFR were associated with all-cause death (HR = 3.12, 95% CI = 1.63-5.98). CONCLUSIONS: In addition to patients with low eGFR levels at baseline, also those with decreasing eGFR have increased risk for vascular events and death; hence, repeated estimates of eGFR might add relevant information to risk prediction.