Genome-Wide DNA Methylation Profiling of the Failing Human Heart with Mechanical Unloading Identifies LINC00881 as an Essential Regulator of Calcium Handling in the Cardiomyocyte [DNA Methylation]
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ABSTRACT: Background: Human heart failure is characterized by global alterations in the myocardial DNA methylation profile, yet little is known about epigenetic regulation of non- coding transcripts and potential reversibility of DNA methylation with left ventricular assist device (LVAD) support. Method: High-density genome-wide mapping of myocardial DNA methylation was performed in 36 patients with end-stage heart failure at the time of LVAD implant and 8 patients at the time of LVAD explant using bead-based array platform. Transcriptomic and functional studies were performed in human induced pluripotent stem cell derived cardiomyocytes (iPSCs). Results: Etiology-specific analysis revealed 2079 differentially methylated positions (DMPs) in ischemic cardiomyopathy (ICM) and 261 DMPs in non-ischemic cardiomyopathy (NICM). 192 DMPs were common to ICM and NICM. Analysis of paired samples before and after LVAD support demonstrated reverse methylation of only 3.2% of HF-specific DMPs. Methylation-expression correlation analysis yielded several protein-coding genes that are hypomethylated and upregulated (HTRA1, FAM65A, FBXO16, EFCAB13, AKAP13, RPTOR) or hypermethylated and downregulated (TBX3) in ICM and NICM patients. A novel cardiac-specific super-enhancer lncRNA (LINC00881) is hypermethylated and downregulated in the failing human heart. LINC00881 is an upstream regulator of sarcomere and calcium channel gene expression including MYH6, CACNA1C, and RYR2. LINC00881 knockdown significantly reduced peak calcium amplitude in the beating human iPSCs. Conclusions: Failing human heart exhibits etiology-specific changes in DNA methylation including coding and non-coding regions, which are minimally reversible with mechanical unloading. Epigenetic reprogramming may be necessary to achieve transcriptional normalization and sustained clinical recovery from heart failure.
Project description:Background: Human heart failure is characterized by global alterations in the myocardial DNA methylation profile, yet little is known about epigenetic regulation of non- coding transcripts and potential reversibility of DNA methylation with left ventricular assist device (LVAD) support. Method: High-density genome-wide mapping of myocardial DNA methylation was performed in 36 patients with end-stage heart failure at the time of LVAD implant and 8 patients at the time of LVAD explant using bead-based array platform. Transcriptomic and functional studies were performed in human induced pluripotent stem cell derived cardiomyocytes (iPSCs). Results: Etiology-specific analysis revealed 2079 differentially methylated positions (DMPs) in ischemic cardiomyopathy (ICM) and 261 DMPs in non-ischemic cardiomyopathy (NICM). 192 DMPs were common to ICM and NICM. Analysis of paired samples before and after LVAD support demonstrated reverse methylation of only 3.2% of HF-specific DMPs. Methylation-expression correlation analysis yielded several protein-coding genes that are hypomethylated and upregulated (HTRA1, FAM65A, FBXO16, EFCAB13, AKAP13, RPTOR) or hypermethylated and downregulated (TBX3) in ICM and NICM patients. A novel cardiac-specific super-enhancer lncRNA (LINC00881) is hypermethylated and downregulated in the failing human heart. LINC00881 is an upstream regulator of sarcomere and calcium channel gene expression including MYH6, CACNA1C, and RYR2. LINC00881 knockdown significantly reduced peak calcium amplitude in the beating human iPSCs. Conclusions: Failing human heart exhibits etiology-specific changes in DNA methylation including coding and non-coding regions, which are minimally reversible with mechanical unloading. Epigenetic reprogramming may be necessary to achieve transcriptional normalization and sustained clinical recovery from heart failure.
Project description:Heart failure is associated with high morbidity and mortality and its incidence increases worldwide. MicroRNAs (miRNAs) are potential markers and targets for diagnostic and therapeutic applications, respectively. We determined myocardial and circulating miRNA abundance and its changes in patients with stable and end-stage heart failure before and at different time points after mechanical unloading by a left ventricular assist device (LVAD) by small-RNA-sequencing. MiRNA changes in failing heart tissues partially resembled that of fetal myocardium. Consistent with prototypical miRNA–target-mRNA interactions, target mRNA levels were negatively correlated to changes in abundance for highly expressed miRNAs in heart failure and fetal hearts. The circulating small RNA profile was dominated by miRNAs, and fragments of tRNAs and small cytoplasmic RNAs. Heart- and muscle-specific circulating miRNAs (myomirs) increased up to 140-fold in advanced heart failure, which coincided with a similar increase in cardiac troponin I protein, the established marker for heart injury. These extracellular changes nearly completely reversed 3 months following initiation of LVAD support. In stable heart failure, circulating miRNAs showed less than 5-fold differences compared to normal, and myomir and cardiac troponin I levels were only captured near the detection limit. These findings provide the underpinning for miRNA-based therapies and emphasize the usefulness of circulating miRNAs as biomarkers for heart injury performing similar to established diagnostic protein biomarkers. Total RNA isolated from human left ventricular myocardium of failing hearts due to dilated or ischemic cardiomyopathy before and after mechanical unloading by a left ventricular assist device (LVAD), and fetal myocardium compared to non-failing postnatal myocardium.
Project description:The microtubule (MT) cytoskeleton can provide a mechanical resistance that can impede the motion of contracting cardiomyocytes. Yet a role of the MT network in human heart failure is unexplored. Here we utilize mass spectrometry to characterize changes to the cytoskeleton in human heart failure. Proteomic analysis of left ventricle tissue reveals a consistent upregulation and stabilization of intermediate filaments and MTs in human heart failure. This dataset includes left ventricular (LV) myocardium from 34 human hearts – either non-failing (NF) or failing hearts. NF hearts are subdivided into normal or compensated hypertrophy (cHyp), while failing hearts are subdivided into ischemic cardiomyopathy (ICM), dilated cardiomyopathy (DCM), and hypertrophic cardiomyopathy with preserved or reduced ejection fraction (HCMpEF and HCMrEF, respectively). Further details on patient classification and in vivo parameters on each heart are listed in sample details.txt.
Project description:Complete transcriptome profiling in human failing and non-failing control hearts using next-gen sequencing Poly-A selected RNA and small RNA sequencing carried out in 5 groups of samples: NF, ICM, NICM, ICM+LVAD, NICM+LVAD
Project description:Oxidative stress plays a key role in development and progression of cardiovascular diseases and it is correlated with left ventricular dysfunction and heart failure (HF). Oxidative environments lead to the formation of intra- and intermolecular disulfide bonds, as well as to plethora of other reversible and irreversible oxidative amino acid modifications, affecting the functionality of the proteins. Here we report that heart failure due to ischemic cardiomyopathy (ICM) or dilated cardiomyopathy (DCM) is correlated with increase in oxidative stress compared to non-failing control hearts, manifested through decreased GSH/GSSG ratio in failing heart tissue samples and adaptations of cardiac redox proteome which occur in correlation with two different heart pathologies.
Project description:Heart failure is associated with high morbidity and mortality and its incidence increases worldwide. MicroRNAs (miRNAs) are potential markers and targets for diagnostic and therapeutic applications, respectively. We determined myocardial and circulating miRNA abundance and its changes in patients with stable and end-stage heart failure before and at different time points after mechanical unloading by a left ventricular assist device (LVAD) by small-RNA-sequencing. MiRNA changes in failing heart tissues partially resembled that of fetal myocardium. Consistent with prototypical miRNAM-bM-^@M-^Starget-mRNA interactions, target mRNA levels were negatively correlated to changes in abundance for highly expressed miRNAs in heart failure and fetal hearts. The circulating small RNA profile was dominated by miRNAs, and fragments of tRNAs and small cytoplasmic RNAs. Heart- and muscle-specific circulating miRNAs (myomirs) increased up to 140-fold in advanced heart failure, which coincided with a similar increase in cardiac troponin I protein, the established marker for heart injury. These extracellular changes nearly completely reversed 3 months following initiation of LVAD support. In stable heart failure, circulating miRNAs showed less than 5-fold differences compared to normal, and myomir and cardiac troponin I levels were only captured near the detection limit. These findings provide the underpinning for miRNA-based therapies and emphasize the usefulness of circulating miRNAs as biomarkers for heart injury performing similar to established diagnostic protein biomarkers. Total RNA isolated from human left ventricular myocardium of failing hearts due to dilated or ischemic cardiomyopathy before and after mechanical unloading by a left ventricular assist device, and fetal myocardium compared to non-failing postnatal myocardium was subjected to multiplexed small RNA-sequencing on the Illumina platform. mRNA gene expression data using Illumina HumanHT-12v4 beadarrays for a subset of the myocardial samples is available (GSE52601).
Project description:End stage heart failure due to ischemic cardiomyopathy (ICM) and dilated cardiomyopathy (DCM) have similar characteristics, enlargement of the ventricles, relatively thin-walled ventricle, which leads to a limited contraction force and blood loading. Nevertheless, the response for present therapeutics is very variable and the prognosis is still very bad for ICM and DCM in general. Thus, the ability to differentiate the etiologies of heart failure based structural and physiological changes of the heart would be a step forward to enhance the specificity and the success of given therapy.
Project description:In ischemic cardiomyopathy (ICM), left ventricular systolic dysfunction leads to reduced blood flow and oxygen supply to the heart. Alterations in sarcomeric protein function and expression play prominent roles in the onset and progression of cardiomyopathies; however, the molecular mechanisms underlying ICM remain poorly defined. Herein, we have implemented a top-down liquid chromatography (LC)-mass spectrometry (MS)-based proteomics method for the simultaneous quantification of sarcomeric protein expression and modifications in non-failing donor (n = 16) compared to end-stage failing ICM (n = 16) human cardiac tissues. Our top-down proteomics platform provided a “bird’s eye view” of proteoform families with high mass accuracy and reproducibility. In addition, quantification of post-translational modifications (PTMs) and expression reveal significant changes in various sarcomeric proteins extracted from ICM tissues. Changes include altered phosphorylation and expression of cardiac troponin I (cTnI) and enigma homolog 2 (ENH2) as well as a marked increase in muscle LIM protein (MLP) and calsarcin-1 phosphorylation in ICM hearts. Our results imply that the contractile apparatus of the sarcomere is severely dysregulated during ICM. Thus, this study is the first to uncover significant molecular changes to multiple sarcomeric proteins in end-stage ischemic heart failure patients using LC-MS-based top-down proteomics.
Project description:Ischemic and non-ischemic cardiomyopathies have distinct etiologies and underlying disease mechanisms, which require in-depth investigation for improved therapeutic interventions. The goal of this study was to use clinically obtained myocardium from healthy and heart failure patients, and characterize the changes in extracellular matrix (ECM) in ischemic and non-ischemic failing hearts, with and without mechanical unloading. Using tissue engineering methodologies, we also investigated how diseased human ECM, in the absence of systemic factors, can influence cardiomyocyte function. Heart tissues from heart failure patients with ischemic and non-ischemic cardiomyopathy were compared to explore differential disease phenotypes and reverse remodeling potential of left ventricular assisted device (LVAD) support at transcriptomic, proteomic and structural levels. The collected data demonstrated that the differential ECM compositions recapitulated the disease microenvironment and induced cardiomyocytes to undergo disease-like functional alterations. In addition, our study also revealed molecular profiles of non-ischemic and ischemic heart failure patients and explored the underlying mechanisms of etiology-specific impact on clinical outcome of LVAD support and tendency towards reverse remodeling.
Project description:Changes in gene expression contribute to the pathogenesis of heart failure. The sequence, expression level, and structure of the human cardiac transcriptome are incompletely described, as are their changes in heart disease. High throughput transcriptome sequencing (RNA-seq) is a quantitative and unbiased approach to measure transcript level and to identify novel transcribed elements or transcript splicing. Here we acquired 975.2 x 106 mapped RNA-seq reads in 15 control and 15 ischemic cardiomyopathy (ICM) hearts, obtained at the time of heart transplantation. We identified over 1000 differentially expressed transcripts, and thousands of novel transcribed elements, some of which were differentially expressed in between control and ICM groups. We found that transcript processing of several cardiac genes was deranged in ICM. For instance, the ratio between specific MYH6 exons was significantly changed in ICM compared to controls, while this type of inter-exon variation was not observed for the adjoining gene MYH7. This RNA-seq study of the human heart failure transcriptome revealed the diversity of transcripts expressed in the human heart and their complex patterns of expression in the diseased heart. Transcriptome profiling (RNA-seq) of 15 control and 15 ischemic cardiomyopathy (ICM) hearts using Illumina GAII and SOLiD