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1.
Eur J Heart Fail ; 2024 May 29.
Article in English | MEDLINE | ID: mdl-38812292

ABSTRACT

AIMS: Data on the prognostic impact of residual tricuspid regurgitation (TR) after tricuspid transcatheter edge-to-edge repair (T-TEER) are scarce. The aim of this analysis was to evaluate 2-year survival and symptomatic outcomes of patients in relation to residual TR after T-TEER. METHODS AND RESULTS: Using the large European Registry of Transcatheter Repair for Tricuspid Regurgitation (EuroTR registry) we investigated the impact of residual TR on 2-year all-cause mortality and New York Heart Association (NYHA) functional class at follow-up. The study further identified predictors for residual TR ≥3+ using a logistic regression model. The study included a total of 1286 T-TEER patients (mean age 78.0 ± 8.9 years, 53.6% female). TR was successfully reduced to ≤1+ in 42.4%, 2+ in 40.0% and 3+ in 14.9% of patients at discharge, while 2.8% remained with TR ≥4+ after the procedure. Residual TR ≥3+ was an independent multivariable predictor of 2-year all-cause mortality (hazard ratio 2.06, 95% confidence interval 1.30-3.26, p = 0.002). The prevalence of residual TR ≥3+ was four times higher in patients with higher baseline TR (vena contracta >11.1 mm) and more severe tricuspid valve tenting (tenting area >1.92 cm2). Of note, no survival difference was observed in patients with residual TR ≤1+ versus 2+ (76.2% vs. 73.1%, p = 0.461). The rate of NYHA functional class ≥III at follow-up was significantly higher in patients with residual TR ≥3+ (52.4% vs. 40.5%, p < 0.001). Of note, the degree of TR reduction significantly correlated with the extent of symptomatic improvement (p = 0.012). CONCLUSIONS: T-TEER effectively reduced TR severity in the majority of patients. While residual TR ≥3+ was associated with worse outcomes, no differences were observed for residual TR 1+ versus 2+. Symptomatic improvement correlated with the degree of TR reduction.

2.
ESC Heart Fail ; 10(2): 1003-1012, 2023 04.
Article in English | MEDLINE | ID: mdl-36514259

ABSTRACT

AIMS: Wildtype transthyretin amyloid cardiomyopathy is an under-recognized cause of heart failure in elderly patients. Transcatheter tricuspid valve repair is a newly emerging therapeutic option for severe tricuspid regurgitation (TR). We present first insights into safety and possible benefits of this procedure in patients with cardiac amyloidosis. METHODS AND RESULTS: Eight patients with cardiac non-hereditary (wildtype) transthyretin (ATTRwt) amyloidosis and severe to torrential TR, undergoing successful transcatheter tricuspid valve repair, were included in the analysis and compared to a control group of 21 patients without cardiac amyloidosis. All patients presented with an advanced stage of amyloid cardiomyopathy. Primary endpoint was reduction in TR at 3 months follow-up. Secondary endpoints were feasibility, safety, hospitalization or death, clinical improvement, cardiac biomarkers, and structural and functional right heart parameter obtained by echocardiography. Transcatheter tricuspid valve repair resulted in a significant reduction of TR (IV to II, P = 0.008) in all eight patients with cardiac amyloidosis (100%). Device success (amyloidosis 75% vs. control group 86%, P = 0.597) and overall probability of hospitalization or death (amyloidosis 13% vs. control group 25%, P = 0.646) were similar compared with those in the control group at 3 months follow-up. Transcatheter tricuspid valve repair led to an improvement of New York Heart Association functional class (P = 0.031) and 6 min walking distance (from 313 ± 118 to 337 ± 106, P = 0.012). TR reduction in amyloidosis patients was less extensive compared with that in control group (TR-reduction 1.6 ± 0.3, P = 0.008 vs. control group 2.3 ± 0.3, P < 0.0001). Furthermore, these patients showed no significant improvement of structural right heart parameters. CONCLUSIONS: Transcatheter tricuspid valve repair is a safe and feasible new treatment option in patients with amyloid cardiomyopathy and has the potential to improve TR-grade and clinical status. However, the benefit appears to be less pronounced compared with patients without cardiac amyloidosis.


Subject(s)
Amyloidosis , Cardiac Catheterization , Tricuspid Valve Insufficiency , Tricuspid Valve , Aged , Humans , Amyloidosis/complications , Amyloidosis/diagnosis , Amyloidosis/surgery , Cardiac Catheterization/methods , Prealbumin , Treatment Outcome , Tricuspid Valve/surgery , Tricuspid Valve Insufficiency/complications , Tricuspid Valve Insufficiency/diagnosis , Tricuspid Valve Insufficiency/surgery
3.
Internist (Berl) ; 63(4): 448-452, 2022 Apr.
Article in German | MEDLINE | ID: mdl-35129621

ABSTRACT

BACKGROUND: Atrial septal defects (ASD) following endovascular mitral valve clipping are potentially hemodynamically relevant complications. Immediate closure with an occluder can represent a safe and effective treatment. An 81-year-old female patient suffering from severe dyspnea due to previously known severe mitral valve regurgitation was scheduled for elective mitral valve clipping. The clip was successfully implanted. Removal of the transseptal cannula resulted in a sudden drop in oxygen saturation and systolic blood pressure as well as an immediate increase in central venous pressure. An iatrogenic left-right shunt was observed at the atrial level with a relevant shunt volume. Immediate closure using an atrial septal occluder successfully restored the oxygen saturation and hemodynamic parameters. CONCLUSION: An increase in central venous pressure, reduction of systolic blood pressure or oxygen saturation after withdrawal of the transseptal cannula during mitral valve clipping should always be further investigated regarding a possible ASD.


Subject(s)
Mitral Valve Insufficiency , Mitral Valve , Aged, 80 and over , Blood Pressure , Cardiac Catheterization , Central Venous Pressure , Female , Humans , Mitral Valve/surgery , Mitral Valve Insufficiency/diagnosis , Mitral Valve Insufficiency/surgery , Oxygen Saturation
4.
ESC Heart Fail ; 9(2): 866-873, 2022 04.
Article in English | MEDLINE | ID: mdl-35137567

ABSTRACT

AIMS: Several new percutaneous tricuspid repair systems have recently been introduced as new treatment options for severe tricuspid regurgitation (TR). Clinical improvement following percutaneous tricuspid valve leaflet repair has been demonstrated by recent studies. A possible impact on exercise capacity has not yet been reported. METHODS AND RESULTS: Eleven patients with at least severe TR and successful tricuspid leaflet repair using the PASCAL Ace implant at our cardiology department were included in this analysis. All patients suffered from symptomatic right-sided heart failure with compromised exercise capacity. Cardiopulmonary exercise testing (CPET), clinical, laboratory, and echocardiographic parameters were assessed at baseline and 3 months follow-up. The primary endpoint was the change in maximal oxygen consumption [VO2 max (mL/(min*kg))] at 3 months follow-up. Secondary endpoints included improvement in TR, cardiac biomarkers, and other clinical outcomes. TR severity at 3 months follow-up post-PASCAL Ace implantation was significantly lower than at baseline (P = 0.004). Cardiac biomarkers including high-sensitivity troponin T and N-terminal pro-brain natriuretic peptide as well as right ventricular diameter improved slightly without reaching statistical significance (P = 0.89, P = 0.32, and P = 0.06, respectively). PASCAL Ace implantation resulted in a significant improvement in cardiopulmonary exercise capacity at 3 months follow-up compared with baseline. Mean VO2 max improved from 9.5 ± 2.8 to 11.4 ± 3.4 mL/(min*kg) (P = 0.006), VO2 max per cent predicted from 42 ± 12% to 50 ± 15% (P = 0.004), peak oxygen uptake from 703 ± 175 to 826 ± 198 mL/min (P = 0.004), and O2 pulse per cent predicted from 67 ± 21% to 81 ± 25% (P = 0.011). Other CPET-related outcomes did not show any significant change over time. CONCLUSIONS: In this single-centre retrospective analysis, direct tricuspid valve leaflet repair using the transcatheter PASCAL Ace implant system was associated with a reduced TR severity and improved cardiopulmonary exercise capacity.


Subject(s)
Heart Valve Prosthesis Implantation , Tricuspid Valve Insufficiency , Cardiac Catheterization/methods , Heart Valve Prosthesis Implantation/methods , Humans , Retrospective Studies , Time Factors , Treatment Outcome , Tricuspid Valve Insufficiency/complications , Tricuspid Valve Insufficiency/diagnosis , Tricuspid Valve Insufficiency/surgery
5.
Cell Rep Med ; 2(11): 100436, 2021 11 16.
Article in English | MEDLINE | ID: mdl-34841289

ABSTRACT

Cellular morphology has the capacity to serve as a surrogate for cellular state and functionality. However, primary cardiomyocytes, the standard model in cardiovascular research, are highly heterogeneous cells and therefore impose methodological challenges to analysis. Hence, we aimed to devise a robust methodology to deconvolute cardiomyocyte morphology on a single-cell level: C-MORE (cellular morphology recognition) is a workflow from bench to data analysis tailored for heterogeneous primary cells using our R package cmoRe. We demonstrate its utility in proof-of-principle applications such as modulation of canonical hypertrophy pathways and linkage of genotype-phenotype in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). In our pilot study, exposure of cardiomyocytes to blood plasma prior to versus after aortic valve replacement allows identification of a disease fingerprint and reflects partial reversibility following therapeutic intervention. C-MORE is a valuable tool for cardiovascular research with possible fields of application in basic research and personalized medicine.


Subject(s)
Algorithms , Cardiovascular Diseases/pathology , Cardiovascular Diseases/therapy , Liquid Biopsy , Precision Medicine , Single-Cell Analysis , Animals , Aortic Valve Stenosis/pathology , Cell Cycle , Green Fluorescent Proteins/metabolism , Humans , Hypertrophy , Induced Pluripotent Stem Cells/metabolism , Myocytes, Cardiac/pathology , Phenotype , Rats , Reproducibility of Results
6.
EMBO Rep ; 22(12): e52170, 2021 12 06.
Article in English | MEDLINE | ID: mdl-34605609

ABSTRACT

The mechanistic target of rapamycin (mTOR) promotes pathological remodeling in the heart by activating ribosomal biogenesis and mRNA translation. Inhibition of mTOR in cardiomyocytes is protective; however, a detailed role of mTOR in translational regulation of specific mRNA networks in the diseased heart is unknown. We performed cardiomyocyte genome-wide sequencing to define mTOR-dependent gene expression control at the level of mRNA translation. We identify the muscle-specific protein Cullin-associated NEDD8-dissociated protein 2 (Cand2) as a translationally upregulated gene, dependent on the activity of mTOR. Deletion of Cand2 protects the myocardium against pathological remodeling. Mechanistically, we show that Cand2 links mTOR signaling to pathological cell growth by increasing Grk5 protein expression. Our data suggest that cell-type-specific targeting of mTOR might have therapeutic value against pathological cardiac remodeling.


Subject(s)
Myocytes, Cardiac , Ventricular Remodeling , Humans , Mechanistic Target of Rapamycin Complex 1/genetics , Mechanistic Target of Rapamycin Complex 1/metabolism , Muscle Proteins , Myocardium/metabolism , Myocytes, Cardiac/metabolism , Signal Transduction , Transcription Factors , Up-Regulation , Ventricular Remodeling/genetics
8.
World J Cardiol ; 13(3): 55-67, 2021 Mar 26.
Article in English | MEDLINE | ID: mdl-33791079

ABSTRACT

BACKGROUND: Elevated interleukin (IL)-6-levels have been described in familial variant transthyretin amyloidosis (ATTRv) associated polyneuropathy and heart failure. However, IL-6 in cardiac ATTR amyloidosis (ATTR-CM) and its prognostic value have not been investigated yet. AIM: We aim to study the correlation between IL-6 levels with clinical presentation (Gillmore-class) and outcome [heart transplantation or death (htx/death)], or the combined endpoint of cardiac decompensation or htx/death in ATTR-CM. METHODS: IL-6 levels of 106 ATTR-CM patients [54 wild-type ATTRwt, 52 ATTRv-CM], 15 asymptomatic carriers of ATTR mutations (aATTRv-CM) and 27 healthy donors were quantified using Luminex technology. Statistical analysis was performed using parametric survival regression models. RESULTS: We found that IL-6 levels from wild-type ATTR patients were significantly elevated compared to healthy controls, while aATTRv-CM carriers and ATTRv-CM patients did not show a significant difference. IL-6 levels showed significantly higher values in increasing Gillmore classes. Univariate analyses revealed association of low IL-6 levels with cardiac decompensation and htx/death [odds ratio: 0.26 (0.09-0.72), P = 0.01] and htx/death [odds ratio: 0.15 (0.04-0.58), P = 0.006]. However, in the multivariate model, no significant improvement of risk prediction was seen for IL-6, while established prognostic factors were significantly associated with outcome. CONCLUSION: Raised IL-6 levels correlate with clinical presentation and are associated with worse outcome in ATTR-CM but do not improve stratification in addition to established risk factors.

9.
Clin Res Cardiol ; 110(4): 579-590, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33481097

ABSTRACT

OBJECTIVES: Direct toxic effects of transthyretin amyloid in patient plasma upon cardiomyocytes are discussed. However, no data regarding the relevance of this putative effect for clinical outcome are available. In this monocentric prospective study, we analyzed cellular hypertrophy after phenylephrine stimulation in vitro in the presence of patient plasma and correlated the cellular growth response with phenotype and prognosis. METHODS AND RESULTS: Progress in automated microscopy and image analysis allows high-throughput analysis of cell morphology. Using the InCell microscopy system, changes in cardiomyocyte's size after treatment with patient plasma from 89 patients suffering from transthyretin amyloidosis and 16 controls were quantified. For this purpose, we propose a novel metric that we named Hypertrophic Index, defined as difference in cell size after phenylephrine stimulation normalized to the unstimulated cell size. Its prognostic value was assessed for multiple endpoints (HTX: death/heart transplantation; DMP: cardiac decompensation; MACE: combined) using Cox proportional hazard models. Cells treated with plasma from healthy controls and hereditary transthyretin amyloidosis with polyneuropathy showed an increase in Hypertrophic Index after phenylephrine stimulation, whereas stimulation after treatment with hereditary cardiac amyloidosis or wild-type transthyretin patient plasma showed a significantly attenuated response. Hypertrophic Index was associated in univariate analyses with HTX (hazard ratio (HR) high vs low: 0.12 [0.02-0.58], p = 0.004), DMP: (HR 0.26 [0.11-0.62], p = 0.003) and MACE (HR 0.24 [0.11-0.55], p < 0.001). Its prognostic value was independent of established risk factors, cardiac TroponinT or N-terminal prohormone brain natriuretic peptide (NTproBNP). CONCLUSIONS: Attenuated cardiomyocyte growth response after stimulation with patient plasma in vitro is an independent risk factor for adverse cardiac events in ATTR patients.


Subject(s)
Amyloid Neuropathies, Familial/therapy , Cell Growth Processes/physiology , Myocytes, Cardiac/pathology , Plasma , Adolescent , Adult , Aged , Aged, 80 and over , Amyloid Neuropathies, Familial/pathology , Cells, Cultured , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prognosis , Prospective Studies , Young Adult
10.
Cardiovasc Res ; 117(1): 201-211, 2021 01 01.
Article in English | MEDLINE | ID: mdl-32176281

ABSTRACT

AIMS: Telomere attrition in cardiomyocytes is associated with decreased contractility, cellular senescence, and up-regulation of proapoptotic transcription factors. Pim1 is a cardioprotective kinase that antagonizes the aging phenotype of cardiomyocytes and delays cellular senescence by maintaining telomere length, but the mechanism remains unknown. Another pathway responsible for regulating telomere length is the transforming growth factor beta (TGFß) signalling pathway where inhibiting TGFß signalling maintains telomere length. The relationship between Pim1 and TGFß has not been explored. This study delineates the mechanism of telomere length regulation by the interplay between Pim1 and components of TGFß signalling pathways in proliferating A549 cells and post-mitotic cardiomyocytes. METHODS AND RESULTS: Telomere length was maintained by lentiviral-mediated overexpression of PIM1 and inhibition of TGFß signalling in A549 cells. Telomere length maintenance was further demonstrated in isolated cardiomyocytes from mice with cardiac-specific overexpression of PIM1 and by pharmacological inhibition of TGFß signalling. Mechanistically, Pim1 inhibited phosphorylation of Smad2, preventing its translocation into the nucleus and repressing expression of TGFß pathway genes. CONCLUSION: Pim1 maintains telomere lengths in cardiomyocytes by inhibiting phosphorylation of the TGFß pathway downstream effectors Smad2 and Smad3, which prevents repression of telomerase reverse transcriptase. Findings from this study demonstrate a novel mechanism of telomere length maintenance and provide a potential target for preserving cardiac function.


Subject(s)
Cellular Senescence/drug effects , Myocytes, Cardiac/drug effects , Proto-Oncogene Proteins c-pim-1/metabolism , Telomere Homeostasis/drug effects , Transforming Growth Factor beta1/pharmacology , A549 Cells , Animals , Humans , Male , Mice, Knockout , Myocytes, Cardiac/enzymology , Phosphorylation , Proto-Oncogene Proteins c-pim-1/genetics , Receptors, Transforming Growth Factor beta/metabolism , Signal Transduction , Smad2 Protein/metabolism , Smad3 Protein/metabolism , Telomerase/metabolism
11.
Clin Res Cardiol ; 110(3): 343-356, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32583062

ABSTRACT

BACKGROUND: Currently, patient selection in TAVI is based upon a multidisciplinary heart team assessment of patient comorbidities and surgical risk stratification. In an era of increasing need for precision medicine and quickly expanding TAVI indications, machine learning has shown promise in making accurate predictions of clinical outcomes. This study aims to predict different intrahospital clinical outcomes in patients undergoing TAVI using a machine learning-based approach. The main clinical outcomes include all-cause mortality, stroke, major vascular complications, paravalvular leakage, and new pacemaker implantations. METHODS AND RESULTS: The dataset consists of 451 consecutive patients undergoing elective TAVI between February 2014 and June 2016. The applied machine learning methods were neural networks, support vector machines, and random forests. Their performance was evaluated using five-fold nested cross-validation. Considering all 83 features, the performance of all machine learning models in predicting all-cause intrahospital mortality (AUC 0.94-0.97) was significantly higher than both the STS risk score (AUC 0.64), the STS/ACC TAVR score (AUC 0.65), and all machine learning models using baseline characteristics only (AUC 0.72-0.82). Using an extreme boosting gradient, baseline troponin T was found to be the most important feature among all input variables. Overall, after feature selection, there was a slightly inferior performance. Stroke, major vascular complications, paravalvular leakage, and new pacemaker implantations could not be accurately predicted. CONCLUSIONS: Machine learning has the potential to improve patient selection and risk management of interventional cardiovascular procedures, as it is capable of making superior predictions compared to current logistic risk scores.


Subject(s)
Aortic Valve/surgery , Heart Valve Diseases/surgery , Inpatients , Machine Learning , Postoperative Complications/epidemiology , Risk Assessment/methods , Transcatheter Aortic Valve Replacement , Aged, 80 and over , Cause of Death/trends , Female , Germany/epidemiology , Heart Valve Diseases/mortality , Hospital Mortality/trends , Humans , Male , Morbidity/trends , Retrospective Studies , Risk Factors , Survival Rate/trends , Time Factors
12.
J Immunol ; 205(8): 2276-2286, 2020 10 15.
Article in English | MEDLINE | ID: mdl-32938726

ABSTRACT

The number and activity of T cell subsets in the atherosclerotic plaques are critical for the prognosis of patients with acute coronary syndrome. ß2 Integrin activation is pivotal for T cell recruitment and correlates with future cardiac events. Despite this knowledge, differential regulation of adhesiveness in T cell subsets has not been explored yet. In this study, we show that in human T cells, SDF-1α-mediated ß2 integrin activation is driven by a, so far, not-described reactive oxidative species (ROS)-regulated calcium influx. Furthermore, we show that CD4+CD28null T cells represent a highly reactive subset showing 25-fold stronger ß2 integrin activation upon SDF-1α stimulation compared with CD28+ T cells. Interestingly, ROS-dependent Ca release was much more prevalent in the pathogenetically pivotal CD28null subset compared with the CD28+ T cells, whereas the established mediators of the classical pathways for ß2 integrin activation (PKC, PI3K, and PLC) were similarly activated in both T cell subsets. Thus, interference with the calcium flux attenuates spontaneous adhesion of CD28null T cells from acute coronary syndrome patients, and calcium ionophores abolished the observed differences in the adhesion properties between CD28+ and CD28null T cells. Likewise, the adhesion of these T cell subsets was indistinguishable in the presence of exogenous ROS/H2O2 Together, these data provide a molecular explanation of the role of ROS in pathogenesis of plaque destabilization.


Subject(s)
Acute Coronary Syndrome/immunology , CD18 Antigens/immunology , CD4-Positive T-Lymphocytes/immunology , Calcium Signaling/immunology , Reactive Oxygen Species/immunology , Acute Coronary Syndrome/pathology , CD28 Antigens/immunology , CD4-Positive T-Lymphocytes/pathology , Chemokine CXCL12/immunology , Female , Humans , Male
14.
J Interv Cardiol ; 31(6): 885-890, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30397939

ABSTRACT

BACKGROUND: To date, there are no guidelines recommending a specific prophylactic antibiotic treatment in transcatheter aortic valve replacement (TAVR). The aim of this study is to evaluate clinical data after TAVR with different periprocedural antibiotic regimens. METHODS: In May 2015 the institutional rules for periprocedural antibiotic prophylaxis were changed from 3 days to 1 day. Thus, a total of 450 consecutive TAVR patients between February 2014 and June 2016 were classified into two intention-to-treat groups: patients receiving a 1-day Cefuroxime prophylaxis (N = 225); patients receiving a 3-day Cefuroxime prophylaxis (N = 225). RESULTS: One-day Cefuroxime regimen was not associated with shorter hospitalization (3-day Cefuroxime 9 ± 4.7 vs 1-day Cefuroxime 8.9 ± 4.0; P = 0.87). Incidence of diarrhea (26.2% vs 18.2%; P = 0.04) and Clostridium difficile infections (4% vs 0.4%; P = 0.01) were significantly higher in the 3-day group. No endocarditis was registered after 1 year follow-up. There was no difference in 30-day overall mortality rate, major vascular complications, bleeding complications, pacemaker-implantation rate, paravalvular regurgitation, or acute kidney injury between patients groups. CONCLUSION: Three-day Cefuroxime prophylaxis does not seem to be advantageous compared to a shorter 1-day regimen, but even shows a significantly higher incidence of diarrhea and Clostridium difficile infection.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Antibiotic Prophylaxis/methods , Cefuroxime/administration & dosage , Transcatheter Aortic Valve Replacement/adverse effects , Aged , Aged, 80 and over , Anti-Bacterial Agents/adverse effects , Antibiotic Prophylaxis/adverse effects , Aortic Valve/surgery , Aortic Valve Stenosis/surgery , Cefuroxime/adverse effects , Female , Hospital Mortality , Humans , Intention to Treat Analysis , Length of Stay/statistics & numerical data , Male , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Postoperative Complications/prevention & control , Retrospective Studies , Risk Factors , Treatment Outcome
15.
J Mol Cell Cardiol ; 100: 54-63, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27721024

ABSTRACT

BACKGROUND: Myocardial infarction is followed by cardiac dysfunction, cellular death, and ventricular remodeling, including tissue fibrosis. S100A4 protein plays multiple roles in cellular survival, and tissue fibrosis, but the relative role of the S100A4 in the myocardium after myocardial infarction is unknown. This study aims to investigate the role of S100A4 in myocardial remodeling and cardiac function following infarct damage. METHODS AND RESULTS: S100A4 expression is low in the adult myocardium, but significantly increased following myocardial infarction. Deletion of S100A4 increased cardiac damage after myocardial infarction, whereas cardiac myocyte-specific overexpression of S100A4 protected the infarcted myocardium. Decreased cardiac function in S100A4 Knockout mice was accompanied with increased cardiac remodeling, fibrosis, and diminished capillary density in the remote myocardium. Loss of S100A4 caused increased apoptotic cell death both in vitro and in vivo in part mediated by decreased VEGF expression. Conversely, S100A4 overexpression protected cells against apoptosis in vitro and in vivo. Increased pro-survival AKT-signaling explained reduced apoptosis in S100A4 overexpressing cells. CONCLUSION: S100A4 expression protects cardiac myocytes against myocardial ischemia and is required for stabilization of cardiac function after MI.


Subject(s)
Myocardial Ischemia/genetics , Myocardial Ischemia/metabolism , Myocardium/metabolism , S100 Calcium-Binding Protein A4/genetics , Stress, Physiological/genetics , Animals , Cell Death/genetics , Disease Models, Animal , Echocardiography , Gene Expression , Hemodynamics , Mice , Mice, Knockout , Myocardial Infarction/diagnosis , Myocardial Infarction/genetics , Myocardial Infarction/metabolism , Myocardial Infarction/physiopathology , Myocardial Ischemia/diagnosis , Myocardial Ischemia/physiopathology , Myocardium/pathology , S100 Calcium-Binding Protein A4/metabolism , Ventricular Remodeling
18.
PLoS Pathog ; 10(7): e1004249, 2014 Jul.
Article in English | MEDLINE | ID: mdl-25079373

ABSTRACT

Coxsackievirus B (CVB) is an enterovirus that most commonly causes a self-limited febrile illness in infants, but cases of severe infection can manifest in acute myocarditis. Chronic consequences of mild CVB infection are unknown, though there is an epidemiologic association between early subclinical infections and late heart failure, raising the possibility of subtle damage leading to late-onset dysfunction, or chronic ongoing injury due to inflammatory reactions during latent infection. Here we describe a mouse model of juvenile infection with a subclinical dose of coxsackievirus B3 (CVB3) which showed no evident symptoms, either immediately following infection or in adult mice. However following physiological or pharmacologically-induced cardiac stress, juvenile-infected adult mice underwent cardiac hypertrophy and dilation indicative of progression to heart failure. Evaluation of the vasculature in the hearts of adult mice subjected to cardiac stress showed a compensatory increase in CD31+ blood vessel formation, although this effect was suppressed in juvenile-infected mice. Moreover, CVB3 efficiently infected juvenile c-kit+ cells, and cardiac progenitor cell numbers were reduced in the hearts of juvenile-infected adult mice. These results suggest that the exhausted cardiac progenitor cell pool following juvenile CVB3 infection may impair the heart's ability to increase capillary density to adapt to increased load.


Subject(s)
Coxsackievirus Infections/pathology , Enterovirus B, Human/pathogenicity , Fibrosis/pathology , Heart/growth & development , Myocytes, Cardiac/cytology , Stem Cells/cytology , Animals , Cell Differentiation , Coxsackievirus Infections/virology , Disease Models, Animal , Female , Fibrosis/virology , Heart/virology , Heart Failure/chemically induced , Heart Failure/pathology , Heart Failure/virology , Male , Mice , Mice, Inbred BALB C , Myocytes, Cardiac/virology , Stem Cells/virology , Stress, Physiological
19.
Circ Res ; 115(3): 376-87, 2014 Jul 18.
Article in English | MEDLINE | ID: mdl-24916111

ABSTRACT

RATIONALE: The senescent cardiac phenotype is accompanied by changes in mitochondrial function and biogenesis causing impairment in energy provision. The relationship between myocardial senescence and Pim kinases deserves attention because Pim-1 kinase is cardioprotective, in part, by preservation of mitochondrial integrity. Study of the pathological effects resulting from genetic deletion of all Pim kinase family members could provide important insight about cardiac mitochondrial biology and the aging phenotype. OBJECTIVE: To demonstrate that myocardial senescence is promoted by loss of Pim leading to premature aging and aberrant mitochondrial function. METHODS AND RESULTS: Cardiac myocyte senescence was evident at 3 months in Pim triple knockout mice, where all 3 isoforms of Pim kinase family members are genetically deleted. Cellular hypertrophic remodeling and fetal gene program activation were followed by heart failure at 6 months in Pim triple knockout mice. Metabolic dysfunction is an underlying cause of cardiac senescence and instigates a decline in cardiac function. Altered mitochondrial morphology is evident consequential to Pim deletion together with decreased ATP levels and increased phosphorylated AMP-activated protein kinase, exposing an energy deficiency in Pim triple knockout mice. Expression of the genes encoding master regulators of mitochondrial biogenesis, PPARγ (peroxisome proliferator-activated receptor gamma) coactivator-1 α and ß, was diminished in Pim triple knockout hearts, as were downstream targets included in mitochondrial energy transduction, including fatty acid oxidation. Reversal of the dysregulated metabolic phenotype was observed by overexpressing c-Myc (Myc proto-oncogene protein), a downstream target of Pim kinases. CONCLUSIONS: Pim kinases prevent premature cardiac aging and maintain a healthy pool of functional mitochondria leading to efficient cellular energetics.


Subject(s)
Aging, Premature/metabolism , Cardiomegaly/metabolism , Mitochondria, Heart/metabolism , Myocytes, Cardiac/metabolism , Proto-Oncogene Proteins c-pim-1/genetics , Aging, Premature/genetics , Aging, Premature/pathology , Animals , Cardiomegaly/pathology , Cell Line, Transformed , Cell Respiration/genetics , Cellular Senescence/genetics , Fibroblasts/cytology , Fibroblasts/metabolism , Humans , Mice , Mice, Knockout , Myocytes, Cardiac/cytology , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha , Proto-Oncogene Mas , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Proto-Oncogene Proteins c-pim-1/metabolism , RNA, Small Interfering/genetics , Rats , Telomere/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism
20.
EMBO Mol Med ; 6(1): 57-65, 2014 01.
Article in English | MEDLINE | ID: mdl-24408966

ABSTRACT

Diabetes is a multi-organ disease and diabetic cardiomyopathy can result in heart failure, which is a leading cause of morbidity and mortality in diabetic patients. In the liver, insulin resistance contributes to hyperglycaemia and hyperlipidaemia, which further worsens the metabolic profile. Defects in mTOR signalling are believed to contribute to metabolic dysfunctions in diabetic liver and hearts, but evidence is missing that mTOR activation is causal to the development of diabetic cardiomyopathy. This study shows that specific mTORC1 inhibition by PRAS40 prevents the development of diabetic cardiomyopathy. This phenotype was associated with improved metabolic function, blunted hypertrophic growth and preserved cardiac function. In addition PRAS40 treatment improves hepatic insulin sensitivity and reduces systemic hyperglycaemia in obese mice. Thus, unlike rapamycin, mTORC1 inhibition with PRAS40 improves metabolic profile in diabetic mice. These findings may open novel avenues for therapeutic strategies using PRAS40 directed against diabetic-related diseases.


Subject(s)
Diabetic Cardiomyopathies/prevention & control , Insulin/metabolism , Myocytes, Cardiac/metabolism , Phosphoproteins/metabolism , Adenoviridae/genetics , Animals , Cells, Cultured , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/metabolism , Diabetic Cardiomyopathies/etiology , Diet, High-Fat , Genetic Vectors/metabolism , Male , Mechanistic Target of Rapamycin Complex 1 , Metabolome , Mice , Mice, Inbred C57BL , Mice, Obese , Multiprotein Complexes/antagonists & inhibitors , Multiprotein Complexes/metabolism , Myocytes, Cardiac/cytology , Obesity/complications , Obesity/metabolism , Phenotype , Phosphoproteins/genetics , TOR Serine-Threonine Kinases/antagonists & inhibitors , TOR Serine-Threonine Kinases/metabolism
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