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Despite advances in our understanding of myocardial recovery among left ventricular assist device (LVAD) patients, with 10-30% of patients achieving substantial myocardial improvement, the rates of LVAD support cessation remain extremely low (1-2%). These numbers are in stark contrast to clinical trial data where successful LVAD cessation is reported in up to 47% of patients. The majority of LVAD programs lack structured recovery programs and targeted protocols, likely underscoring the heterogeneity that exists among LVAD patients with myocardial recovery. This perspective summarizes the current medical and surgical challenges with respect to 1) identifying the appropriate candidates for LVAD cessation; 2) methods to wean LVAD support; 3) reviewing surgical techniques for cessation of current generation HeartMate 3 LVAD; and 4) approaching shared decision making for LVAD cessation between patients and providers given the uncertainties that remain in the field.
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Insuficiencia Cardíaca , Corazón Auxiliar , Humanos , Insuficiencia Cardíaca/cirugía , ObjetivosRESUMEN
Heart failure (HF) is characterized by global alterations in myocardial DNA methylation, yet little is known about the epigenetic regulation of the noncoding genome and potential reversibility of DNA methylation with left ventricular assist device (LVAD) therapy. Genome-wide mapping of myocardial DNA methylation in 36 patients with HF at LVAD implantation, 8 patients at LVAD explantation, and 7 nonfailing (NF) donors using a high-density bead array platform identified 2,079 differentially methylated positions (DMPs) in ischemic cardiomyopathy (ICM) and 261 DMPs in nonischemic cardiomyopathy (NICM). LVAD support resulted in normalization of 3.2% of HF-associated DMPs. Methylation-expression correlation analysis yielded several protein-coding genes that are hypomethylated and upregulated (HTRA1, FBXO16, EFCAB13, and AKAP13) or hypermethylated and downregulated (TBX3) in HF. A potentially novel cardiac-specific super-enhancer long noncoding RNA (lncRNA) (LINC00881) is hypermethylated and downregulated in human HF. LINC00881 is an upstream regulator of sarcomere and calcium channel gene expression including MYH6, CACNA1C, and RYR2. LINC00881 knockdown reduces peak calcium amplitude in the beating human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). These data suggest that HF-associated changes in myocardial DNA methylation within coding and noncoding genomes are minimally reversible with mechanical unloading. Epigenetic reprogramming strategies may be necessary to achieve sustained clinical recovery from heart failure.
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Cardiomiopatías , Proteínas F-Box , Insuficiencia Cardíaca , Células Madre Pluripotentes Inducidas , Humanos , Epigénesis Genética , Metilación de ADN , Células Madre Pluripotentes Inducidas/metabolismo , Insuficiencia Cardíaca/genética , Miocitos Cardíacos/metabolismo , Cardiomiopatías/metabolismo , Proteínas F-Box/metabolismo , Serina Peptidasa A1 que Requiere Temperaturas Altas/genética , Serina Peptidasa A1 que Requiere Temperaturas Altas/metabolismoRESUMEN
Acute decompensated heart failure (ADHF) is a primary cause of older adults presenting to the emergency department with acute dyspnea. Point-of-care lung ultrasound (LUS) has shown comparable or superior diagnostic accuracy in comparison with a chest x-ray (CXR) in patients presenting with symptoms of ADHF. The systematic review and meta-analysis aimed to elucidate the sensitivity and specificity of LUS in comparison with CXR for diagnosing ADHF and summarize the rapidly growing body of evidence in this domain. A total of 5 databases were searched through February 18, 2021, to identify observational studies that reported on the use of LUS compared with CXR in diagnosing ADHF in patients presenting with shortness of breath. Meta-analysis was conducted on the sensitivities and specificities of each diagnostic method. A total of 8 studies reporting on 2,787 patients were included in this meta-analysis. For patients presenting with signs and symptoms of ADHF, LUS was found to be more sensitive than CXR (91.8% vs 76.5%) and more specific than CXR (92.3% vs 87.0%) for the detection of cardiogenic pulmonary edema. In conclusion, LUS is more sensitive and specific than CXR in detecting pulmonary edema. This highlights the importance of sonographic B-lines, along with the accurate interpretation of clinical data, in the diagnosis of ADHF. In addition to its convenience, reduced costs, and reduced radiation exposure, LUS should be considered an effective alternative to CXR for evaluating patients with dyspnea in the setting of ADHF.
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Insuficiencia Cardíaca , Edema Pulmonar , Anciano , Disnea/diagnóstico , Disnea/etiología , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/diagnóstico por imagen , Humanos , Pulmón/diagnóstico por imagen , Sistemas de Atención de Punto , Edema Pulmonar/complicaciones , Edema Pulmonar/diagnóstico por imagen , Radiografía , Radiografía Torácica/efectos adversos , Radiografía Torácica/métodos , Ultrasonografía/métodosRESUMEN
Importance: Heart failure (HF) is often characterized by an insidious disease course leading to frequent rehospitalizations and a high use of ambulatory care. Remote cardiac monitoring is a promising approach to detect worsening HF early and intervene prior to an overt decompensation. Observations: Recently, a multitude of novel technologies for remote cardiac monitoring (RCM) in patients with HF have been developed and are undergoing clinical trials. This development has been accelerated by the COVID-19 pandemic. Conclusions and Relevance: This review summarizes the major clinical trials on RCM in patients with HF and present the most recent developments in noninvasive and invasive RCM technologies.
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COVID-19 , Insuficiencia Cardíaca , Atención Ambulatoria , Insuficiencia Cardíaca/epidemiología , Humanos , Monitoreo Fisiológico , PandemiasRESUMEN
MiRNA-regulated processes are pivotal in cardiovascular homeostasis and disease. These short non-coding RNAs have ideal properties that could be utilized as potential biomarkers; moreover, their functions as post-transcriptional regulators of mRNA make them interesting therapeutic targets. In this review, we summarize the current state of miRNA-based biomarkers in a variety of diseases leading to heart failure, as well as provide an outlook on developing miRNA-based therapies in the heart failure field.
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Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/terapia , MicroARNs/uso terapéutico , Biomarcadores/metabolismo , Sistemas de Liberación de Medicamentos , Insuficiencia Cardíaca/genética , HumanosRESUMEN
AIMS: We aimed to detail the early clinical experience with pVAD 5.5 at a large academic medical centre. Impella® 5.5 (Abiomed) is a temporary peripherally inserted left ventricular assist device (pVAD) used for the treatment of cardiogenic shock (CS). This system has several modifications aimed at improving deliverability and durability over the pVAD 5.0 system, but real-world experience with this device remains limited. METHODS AND RESULTS: We collected clinical and outcome data on all patients supported with pVAD 5.5 at our centre between February and December 2020, including procedural and device-related complications. Fourteen patients with pVAD 5.5 were included. Aetiology of CS was acute myocardial infarction (n = 6), decompensated heart failure (n = 6), suspected myocarditis (n = 1), and post-cardiotomy CS (n = 1). Four patients received pVAD 5.5 after being on inotropes alone, two were escalated from intra-aortic balloon pump, two were escalated from pVAD CP, and six patients were transitioned to pVAD 5.5 from extracorporeal membrane oxygenation. Median duration of pVAD 5.5 support was 12 (interquartile range 7, 25) days. Complications included axillary insertion site haematoma (n = 3), acute kidney injury (n = 3), severe thrombocytopenia (n = 1), and stroke (n = 1). No valve injury or limb complications occurred. Survival to device explant for recovery or transition to another therapy was 11/14 (79%) patients. CONCLUSIONS: In this early experience of the pVAD 5.5, procedural and device-related complications were observed but were manageable, and overall survival was high in this critically ill cohort, particularly when the device was used as a bridge to other therapies.
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Corazón Auxiliar , Choque Cardiogénico , Humanos , Contrapulsador Intraaórtico , Estudios Retrospectivos , Choque Cardiogénico/etiología , Choque Cardiogénico/terapia , Centros de Atención Terciaria , Resultado del TratamientoRESUMEN
AIMS: Allograft rejection following heart transplantation (HTx) is a serious complication even in the era of modern immunosuppressive regimens and causes up to a third of early deaths after HTx. Allograft rejection is mediated by a cascade of immune mechanisms leading to acute cellular rejection (ACR) and/or antibody-mediated rejection (AMR). The gold standard for monitoring allograft rejection is invasive endomyocardial biopsy that exposes patients to complications. Little is known about the potential of circulating miRNAs as biomarkers to detect cardiac allograft rejection. We here present a systematic analysis of circulating miRNAs as biomarkers and predictors for allograft rejection after HTx using next-generation small RNA sequencing. METHODS AND RESULTS: We used next-generation small RNA sequencing to investigate circulating miRNAs among HTx recipients (10 healthy controls, 10 heart failure patients, 13 ACR, and 10 AMR). MiRNA profiling was performed at different time points before, during, and after resolution of the rejection episode. We found three miRNAs with significantly increased serum levels in patients with biopsy-proven cardiac rejection when compared with patients without rejection: hsa-miR-139-5p, hsa-miR-151a-5p, and hsa-miR-186-5p. We identified miRNAs that may serve as potential predictors for the subsequent development of ACR: hsa-miR-29c-3p (ACR) and hsa-miR-486-5p (AMR). Overall, hsa-miR-486-5p was most strongly associated with acute rejection episodes. CONCLUSIONS: Monitoring cardiac allograft rejection using circulating miRNAs might represent an alternative strategy to invasive endomyocardial biopsy.
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Trasplante de Corazón , MicroARNs , Aloinjertos , Biomarcadores , Rechazo de Injerto/diagnóstico , Humanos , MicroARNs/genéticaRESUMEN
BACKGROUND: To facilitate evidence-based medicine (EBM) on an individual level, it may be important for clinical practice guidelines (CPGs) to incorporate the performance parameters of diagnostic studies and therapeutic interventions (such as likelihood ratio and absolute benefit or harm), and to incorporate relevant patient contexts that may influence decision-making. We sought to determine the extent to which heart failure CPGs currently incorporate this information. METHODS: We reviewed the American College of Cardiology Foundation/American Heart Association (ACCF/AHA) 2013 Heart Failure CPG, the 2017 ACCF/AHA/HFSA update, and European Society of Cardiology (ESC) 2016 Heart Failure CPG. We abstracted variables for each CPG recommendation from the following domains: quality of evidence, strength of recommendation, diagnostic and therapeutic performance parameters, and patient context. RESULTS: We examined 169 recommendations from the ACCF/AHA 2013 CPGs and 2017 update and 187 recommendations from the 2016 ESC CPGs. Performance parameters for diagnostic studies (2013 ACCF/AHA: 13%; 2017 ACCF/AHA/HFSA update: 0%; 2016 ESC: 0%) and therapeutic interventions (2013 ACCF/AHA: 65%; 2017 ACCF/AHA/HFSA update: 64%; 2016 ESC: 16%) were not commonly included in CPGs. Patient context was included in about half of ACCF/AHA recommendations and a quarter of ESC recommendations. CONCLUSIONS: The majority of recommendations from heart failure CPGs lack information on diagnostic and therapeutic performance parameters and patient context. Given the importance of these components to effectively implement EBM, particularly for a heterogeneous heart failure population, innovative strategies are needed to optimize CPGs so they provide comprehensive yet succinct recommendations that can improve population-level outcomes and ensure optimal patient-centered care.
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Cardiología , Insuficiencia Cardíaca , American Heart Association , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/terapia , Humanos , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: Presentation of life-threatening arrhythmias concomitantly with a new-onset non-ischaemic cardiomyopathy raises concern for an inflammatory cardiomyopathy such as cardiac sarcoidosis or cardiac manifestations of connective tissue disease. Comprehensive workup for specific aetiologies may be unrevealing except for signs of myocardial inflammation identified on cardiac positron emission tomography (PET). Here, we present five cases of such subjects and their clinical course. CASE SUMMARY: We collected clinical, imaging, pathological, and follow-up data of five subjects presenting with arrhythmias and unexplained new-onset cardiomyopathy. Mean age was 56.2 ± 5.8 years. Three subjects presented with ventricular tachycardia and two with atrial arrhythmias. Echocardiography showed a mean left ventricular ejection fraction of 37 ± 9%. Significant coronary artery disease was ruled out in all cases as the cause of the cardiomyopathy. All patients underwent cardiac magnetic resonance imaging (MRI) and PET scan at presentation and follow-up. In all patients, cardiac MRI revealed hyperenhancement in epicardial and mid-myocardial pattern in a non-coronary distribution, while PET scan revealed fluorodeoxyglucose (FDG) mismatch defects in multiple foci in a non-coronary distribution. Right ventricular biopsy was obtained in all patients and revealed interstitial fibrosis and cardiomyocyte hypertrophy. On median follow-up of 210 days, all subjects had improvement in both heart failure symptoms and arrhythmias and repeat PET in four out of five patients showed decreased inflammation. DISCUSSION: A high level of suspicion for inflammatory cardiomyopathy is needed in patients presenting with new unexplained cardiomyopathy and arrhythmias. A cardiac FDG-PET should be considered for diagnosis if cardiac inflammation is in the differential. This can inform further decisions regarding targeted immunomodulation therapy that may be helpful in this cohort.
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OBJECTIVE: To quantify differences in the diagnosis and treatment of heart failure with preserved ejection fraction (HFpEF) between cardiologists and noncardiologists, who often diagnose and manage HFpEF. METHODS: Cardiologists and noncardiologists (internal medicine, medicine/pediatrics, family medicine, geriatrics) were anonymously surveyed between January 16, 2018, and March 2, 2018, regarding practices related to diagnosing and managing HFpEF at the University of Michigan and Weill Cornell Medical Center. Response data were compared using χ2 analysis. RESULTS: Of 1010 physicians surveyed, 211 completed a significant portion of the survey: 32 cardiologists and 179 noncardiologists. Most noncardiologists were unaware of HFpEF diagnostic guidelines and commonly used left ventricular diastolic dysfunction and natriuretic peptides to diagnose HFpEF. Noncardiologists (32.3%, n=52) were less likely than cardiologists (64.5%, n= 20) to prescribe an aldosterone antagonist for HFpEF (P=.001). Both groups reported similar use of ß-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and exercise programs. Noncardiologists were more likely to refer patients with HFrEF to cardiology (63.1%, n=111) compared with patients with HFpEF (33.5%, n=59; P<.001). Noncardiologists were more likely to discuss prognosis and goals of care with patients with HFrEF (84.4%, n=151) than with patients with HFpEF (65.9%, n=118; P<.001). CONCLUSION: Cardiologists and noncardiologists vary significantly in their HFpEF diagnosis and treatment practices. As diagnostic criteria continue to be evaluated for HFpEF, dissemination of these guidelines to noncardiologists, with an emphasis on the morbidity and mortality associated with HFpEF, is imperative.
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Cardiólogos/estadística & datos numéricos , Insuficiencia Cardíaca Diastólica/diagnóstico , Pautas de la Práctica en Medicina/estadística & datos numéricos , Insuficiencia Cardíaca Diastólica/fisiopatología , Insuficiencia Cardíaca Diastólica/terapia , Humanos , Medicina/estadística & datos numéricos , Derivación y Consulta/estadística & datos numéricos , Volumen Sistólico , Encuestas y CuestionariosAsunto(s)
Sistema de Transporte de Aminoácidos ASC/metabolismo , Glutamina/metabolismo , Insuficiencia Cardíaca/metabolismo , Antígenos de Histocompatibilidad Menor/metabolismo , Miocardio/metabolismo , Sistema de Transporte de Aminoácidos ASC/genética , Estudios de Casos y Controles , Enfermedad Crónica , Regulación hacia Abajo , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Homeostasis , Humanos , Antígenos de Histocompatibilidad Menor/genética , Función Ventricular IzquierdaRESUMEN
BACKGROUND: While an expanding armamentarium of pharmacologic therapies has contributed to improved outcomes among adults with heart failure (HF) over the past two decades, this has also been accompanied by an increase in the number of medications taken by adults with HF. The use of at least 10 medications, defined as hyperpolypharmacy, is particularly notable given its association with adverse outcomes. We aimed to assess the prevalence and identify determinants of hyperpolypharmacy among adults with HF. METHODS: We studied adults aged ≥50 years with self-reported HF from the National Health And Nutrition Examination Survey (NHANES) in 2003-2014. We calculated weighted means and percentages to describe patient characteristics. We conducted a multivariable Poisson regression analysis to identify factors independently associated with hyperpolypharmacy; we adjusted for survey sampling, socio-demographics, comorbidity, geriatric conditions, and health care utilization. We examined 947 participants, representing 4.6 million adults with HF. RESULTS: The prevalence of hyperpolypharmacy was 26%. In a multivariable regression analysis, comorbidity count, ≥10 ambulatory contacts, and ≥ 3 hospitalizations were independently associated with hyperpolypharmacy. Interestingly, functional impairment and cognitive impairment were not independently associated with hyperpolypharmacy; while low annual household income and low educational status were each associated with an almost 2-fold increase in hyperpolypharmacy. CONCLUSION: Hyperpolypharmacy is a common condition among adults with HF. We additionally found that low household income and low educational status are independently associated with hyperpolypharmacy, suggesting that non-medical factors may be contributing to this potentially harmful condition.
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Fármacos Cardiovasculares/uso terapéutico , Insuficiencia Cardíaca/tratamiento farmacológico , Polifarmacia , Anciano , Atención Ambulatoria , Fármacos Cardiovasculares/efectos adversos , Comorbilidad , Estudios Transversales , Escolaridad , Femenino , Estado de Salud , Disparidades en Atención de Salud , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/epidemiología , Hospitalización , Humanos , Renta , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Prevalencia , Factores de Riesgo , Estados Unidos/epidemiologíaRESUMEN
INTRODUCTION: Amyloidosis is caused by dysregulation of protein folding resulting in systemic or organ specific amyloid aggregation. When affecting the heart, amyloidosis can cause severe heart failure, which is associated with a high morbidity and mortality. Different subtypes of cardiac amyloidosis exist e.g. transthyretin cardiac amyloidosis and senile cardiac amyloidosis. Today, diagnostics is primarily based on cardiac biopsies and no clinically used circulating blood-based biomarkers existing. Therefore, our aim was to identify circulating microRNAs in patients with different forms of amyloidosis. METHODS: Blood was collected from healthy subjects (n = 10), patients with reduced ejection fraction (EF < 35%; n = 10), patients affected by transthyretin cardiac amyloidosis (n = 13) as well as senile cardiac amyloidosis (n = 11). After performing TaqMan array profiling, promising candidates, in particular miR-99a-5p, miR-122-5p, miR-27a-3p, miR-221-3p, miR-1180-3p, miR-155-5p, miR-339-3p, miR-574-3p, miR-342-3p and miR-329-3p were validated via quantitative real time PCR. RESULTS: The validation experiments revealed a significant upregulation of miR-339-3p in patients affected with senile cardiac amyloidosis compared to controls. This corresponded to the array profiling results. In contrast, there was no deregulation in the other patient groups. CONCLUSION: MiR-339-3p was increased in blood of patients with senile cardiac amyloidosis. Therefore, miR-339-3p is a potential candidate as biomarker for senile cardiac amyloidosis in future studies. Larger patient cohorts should be investigated.
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Amiloidosis/genética , Cardiopatías/genética , MicroARNs/genética , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Regulación hacia Arriba , Anciano , Anciano de 80 o más Años , Neuropatías Amiloides Familiares/sangre , Neuropatías Amiloides Familiares/genética , Amiloidosis/sangre , Estudios de Casos y Controles , MicroARN Circulante/genética , Femenino , Perfilación de la Expresión Génica , Marcadores Genéticos , Cardiopatías/sangre , Humanos , Masculino , Persona de Mediana EdadRESUMEN
We report a case of a 20-year-old man who presented to our institution with a new arrhythmia on a routine EKG. Serial EKG tracings revealed various abnormal rhythms such as episodes of atrial fibrillation, profound first degree AV block, and type I second degree AV block. He was found to have positive serologies for Borrelia burgdorferi. After initiation of antibiotic therapy, the atrial arrhythmias and AV block resolved. Here, we present a case of Lyme carditis presenting with atrial fibrillation, a highly unusual presentation of Lyme carditis.
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BACKGROUND: Predicting which patients are unlikely to benefit from continuous flow left ventricular assist device (LVAD) treatment is crucial for the identification of appropriate patients. Previously developed scoring systems are limited to past eras of device or restricted to specific devices. Our objective was to create a risk model for patients treated with continuous flow LVAD based on the preimplant variables. METHODS AND RESULTS: We performed a retrospective analysis of all patients implanted with a continuous flow LVAD between 2006 and 2014 at the University of Pennsylvania and included a total of 210 patients (male 78%; mean age, 56±15; mean follow-up, 465±486 days). From all plausible preoperative covariates, we performed univariate Cox regression analysis for covariates affecting the odds of 1-year survival following implantation (P<0.2). These variables were included in a multivariable model and dropped if significance rose above P=0.2. From this base model, we performed step-wise forward and backward selection for other covariates that improved power by minimizing Akaike Information Criteria while maximizing the Harrell Concordance Index. We then used Kaplan-Meier curves, the log-rank test, and Cox proportional hazard models to assess internal validity of the scoring system and its ability to stratify survival. A final optimized model was identified based on clinical and echocardiographic parameters preceding LVAD implantation. One-year mortality was significantly higher in patients with higher risk scores (hazard ratio, 1.38; P=0.004). This hazard ratio represents the multiplied risk of death for every increase of 1 point in the risk score. The risk score was validated in a separate patient cohort of 260 patients at Columbia University, which confirmed the prognostic utility of this risk score (P=0.0237). CONCLUSION: We present a novel risk score and its validation for prediction of long-term survival in patients with current types of continuous flow LVAD support.
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Técnicas de Apoyo para la Decisión , Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Implantación de Prótesis/instrumentación , Función Ventricular Izquierda , Adulto , Anciano , Toma de Decisiones Clínicas , Ecocardiografía , Femenino , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Selección de Paciente , Valor Predictivo de las Pruebas , Diseño de Prótesis , Implantación de Prótesis/efectos adversos , Implantación de Prótesis/mortalidad , Recuperación de la Función , Reproducibilidad de los Resultados , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: Heart failure leads to mitochondrial dysfunction and metabolic abnormalities of the failing myocardium coupled with an energy-depleted state and cardiac remodeling. The mitochondrial deacetylase sirtuin 3 (SIRT3) plays a pivotal role in the maintenance of mitochondrial function through regulating the mitochondrial acetylome. It is interesting to note that unique cardiac and systemic microRNAs have been shown to play an important role in cardiac remodeling by modulating key signaling elements in the myocardium. METHODS: Cellular signaling was analyzed in human cardiomyocyte-like AC16 cells, and acetylation levels in rodent models of SIRT3-/-and transgenic microRNA-195 (miR-195) overexpression were compared with wild type. Luciferase assays, Western blotting, immunoprecipitation assays, and echocardiographic analysis were performed. Enzymatic activities of pyruvate dehydrogenase (PDH) and ATP synthase were measured. RESULTS: In failing human myocardium, we observed induction of miR-195 along with decreased expression of the mitochondrial deacetylase SIRT3 that was associated with increased global protein acetylation. We further investigated the role of miR-195 in SIRT3-mediated metabolic processes and its impact on regulating enzymes involved in deacetylation. Proteomic analysis of the total acetylome showed increased overall acetylation, and specific lysine acetylation of 2 central mitochondrial metabolic enzymes, PDH and ATP synthase, as well. miR-195 downregulates SIRT3 expression through direct 3'-untranslated region targeting. Treatments with either sirtuin inhibitor nicotinamide, small interfering RNA-mediated SIRT3 knockdown or miR-195 overexpression enhanced acetylation of PDH complex and ATP synthase. This effect diminished PDH and ATP synthase activity and impaired mitochondrial respiration.SIRT3-/- and miR-195 transgenic mice consistently showed enhanced global protein acetylation, including PDH complex and ATP synthase, associated with decreased enzymatic activity. CONCLUSIONS: Altogether, these data suggest that increased levels of miR-195 in failing myocardium regulate a novel pathway that involves direct SIRT3 suppression and enzymatic inhibition via increased acetylation of PDH and ATP synthase that are essential for cardiac energy metabolism.
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Metabolismo Energético , Insuficiencia Cardíaca/enzimología , MicroARNs/metabolismo , Mitocondrias Cardíacas/enzimología , Miocitos Cardíacos/enzimología , Procesamiento Proteico-Postraduccional , Sirtuina 3/metabolismo , Acetilación , Animales , Línea Celular , Modelos Animales de Enfermedad , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/fisiopatología , Humanos , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Noqueados , MicroARNs/genética , Mitocondrias Cardíacas/patología , ATPasas de Translocación de Protón Mitocondriales/metabolismo , Miocitos Cardíacos/patología , Complejo Piruvato Deshidrogenasa/metabolismo , Transducción de Señal , Sirtuina 3/deficiencia , Sirtuina 3/genéticaRESUMEN
BACKGROUND: Exosomes are cell-derived circulating vesicles that play an important role in cell-cell communication. Exosomes are actively assembled and carry messenger RNAs, microRNAs and proteins. The "gold standard" for cardiac allograft surveillance is endomyocardial biopsy (EMB), an invasive technique with a distinct complication profile. The development of novel, non-invasive methods for the early diagnosis of allograft rejection is warranted. We hypothesized that the exosomal proteome is altered in acute rejection, allowing for a distinction between non-rejection and rejection episodes. METHODS: Serum samples were collected from heart transplant (HTx) recipients with no rejection, acute cellular rejection (ACR) and antibody-mediated rejection (AMR). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of serum exosome was performed using a mass spectrometer (Orbitrap Fusion Tribrid). RESULTS: Principal component analysis (PCA) revealed a clustering of 3 groups: (1) control and heart failure (HF); (2) HTx without rejection; and (3) ACR and AMR. A total of 45 proteins were identified that could distinguish between groups (q < 0.05). Comparison of serum exosomal proteins from control, HF and non-rejection HTx revealed 17 differentially expressed proteins in at least 1 group (q < 0.05). Finally, comparisons of non-rejection HTx, ACR and AMR serum exosomes revealed 15 differentially expressed proteins in at least 1 group (q < 0.05). Of these 15 proteins, 8 proteins are known to play a role in the immune response. Of note, the majority of proteins identified were associated with complement activation, adaptive immunity such as immunoglobulin components and coagulation. CONCLUSIONS: Characterizing of circulating exosomal proteome in different cardiac disease states reveals unique protein expression patterns indicative of the respective pathologies. Our data suggest that HTx and allograft rejection alter the circulating exosomal protein content. Exosomal protein analysis could be a novel approach to detect and monitor acute transplant rejection and lead to the development of predictive and prognostic biomarkers.
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Exosomas , Rechazo de Injerto/sangre , Rechazo de Injerto/diagnóstico , Trasplante de Corazón , Aloinjertos , HumanosRESUMEN
Abnormal lipid metabolism may contribute to myocardial injury and remodeling. To determine whether accumulation of very long-chain ceramides occurs in human failing myocardium, we analyzed myocardial tissue and serum from patients with severe heart failure (HF) undergoing placement of left ventricular assist devices and controls. Lipidomic analysis revealed increased total and very long-chain ceramides in myocardium and serum of patients with advanced HF. After unloading, these changes showed partial reversibility. Following myocardial infarction (MI), serine palmitoyl transferase (SPT), the rate-limiting enzyme of the de novo pathway of ceramide synthesis, and ceramides were found increased. Blockade of SPT by the specific inhibitor myriocin reduced ceramide accumulation in ischemic cardiomyopathy and decreased C16, C24:1, and C24 ceramides. SPT inhibition also reduced ventricular remodeling, fibrosis, and macrophage content following MI. Further, genetic deletion of the SPTLC2 gene preserved cardiac function following MI. Finally, in vitro studies revealed that changes in ceramide synthesis are linked to hypoxia and inflammation. In conclusion, cardiac ceramides accumulate in the failing myocardium, and increased levels are detectable in circulation. Inhibition of de novo ceramide synthesis reduces cardiac remodeling. Thus, increased de novo ceramide synthesis contributes to progressive pathologic cardiac remodeling and dysfunction.