Project description:Mechanical unloading by ventricular assist devices (VAD) leads to significant gene-expression changes often summarized as reverse remodeling. However, little is known on individual transcriptome changes during VAD-support and its relationship to non-failing hearts (NF). In addition no data are available for the transcriptome regulation during non-pulsatile VAD-support. Therefore we analysed the gene-expression patterns of 30 paired samples from VAD-supported (including 8 non-pulsatile VADs) and 8 non-failing control hearts (NF) using the first total human genome-array available. Transmural myocardial samples were collected for RNA-isolation. RNA was isolated by commercial methods and processed according to chip-manufacturer recommendations. cRNA were hybridized on Affymetrix HG-U133 Plus 2.0 arrays, providing coverage of the whole human genome Array. Data was analyzed using Microarray Analysis Suite 5.0 (Affymetrix) and clustered by Expressionist software (Genedata). 352 transcripts were differentially regulated between samples from VAD-implantation and NF, whereas 510 were significantly regulated between VAD-transplantation and NF (paired t-test p<0.001, fold change >=1.6). Remarkably, only a minor fraction of 111 transcripts was regulated in heart failure (HF) and during VAD-support. Unsupervised hierarchical clustering of paired VAD- and NF-samples revealed separation of HF- and NF- samples, however individual differentiation of VAD-implantation and VAD-transplantation was not accomplished. Clustering of pulsatile and non-pulsatile VAD did not lead to robust separation of gene expression patterns. During VAD-support myocardial gene expression changes do not indicate reversal of the HF-phenotype, but reveal a distinct HF-related pattern. Transcriptome analysis of pulsatile and non-pulsatile VAD-supported hearts did not provide evidence for a pump-mode specific transcriptome pattern. Microarrays were used to elucidate the differences between non-failing control hearts and those, suffering from end-stage heart failure pre and post mechanical unloading.
Project description:Mechanical unloading by ventricular assist devices (VAD) leads to significant gene-expression changes often summarized as reverse remodeling. However, little is known on individual transcriptome changes during VAD-support and its relationship to non-failing hearts (NF). In addition no data are available for the transcriptome regulation during non-pulsatile VAD-support. Therefore we analysed the gene-expression patterns of 30 paired samples from VAD-supported (including 8 non-pulsatile VADs) and 8 non-failing control hearts (NF) using the first total human genome-array available. Transmural myocardial samples were collected for RNA-isolation. RNA was isolated by commercial methods and processed according to chip-manufacturer recommendations. cRNA were hybridized on Affymetrix HG-U133 Plus 2.0 arrays, providing coverage of the whole human genome Array. Data was analyzed using Microarray Analysis Suite 5.0 (Affymetrix) and clustered by Expressionist software (Genedata). 352 transcripts were differentially regulated between samples from VAD-implantation and NF, whereas 510 were significantly regulated between VAD-transplantation and NF (paired t-test p<0.001, fold change >=1.6). Remarkably, only a minor fraction of 111 transcripts was regulated in heart failure (HF) and during VAD-support. Unsupervised hierarchical clustering of paired VAD- and NF-samples revealed separation of HF- and NF- samples, however individual differentiation of VAD-implantation and VAD-transplantation was not accomplished. Clustering of pulsatile and non-pulsatile VAD did not lead to robust separation of gene expression patterns. During VAD-support myocardial gene expression changes do not indicate reversal of the HF-phenotype, but reveal a distinct HF-related pattern. Transcriptome analysis of pulsatile and non-pulsatile VAD-supported hearts did not provide evidence for a pump-mode specific transcriptome pattern.
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: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:Gene expression in right atrial myocardium was compared between non-failing control and tachypaced dogs (heart failure was induced by tachycardic pacing for 6 weeks).
Project description:Analysis of left venticular myocardium following morphine-induced sustained ligand activated preconditioning (SLP). Results provide insight into the molecular pathways affected by morphine-induced SLP in the pre- and post-ischemic heart. Total RNA obtained from isolated ventricular myocardium subjected to 5 days of morphine induced sustained ligand activated preconditioning (SLP) compared to placebo control ventricular myocardium, tissue collected pre- and post-ischemia (n=6/group).
Project description:Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy primarily of the right ventricle characterized through fibrofatty replacement of cardiomyocytes. The genetic etiology in ARVC patients is most commonly caused by dominant inheritance and high genetic heterogeneity. Though histological examinations of ARVC affected human myocardium reveals fibrolipomatous replacement, the molecular mechanisms leading to loss of cardiomyocytes are largely unknown. We therefore analyzed the transcriptomes of 6 ARVC specimen derived from heart transplantation candidates and compared our findings to 6 non-failing donor hearts (NF) which could not be transplanted for technical reasons. In addition, we compared our findings to 7 hearts from patients with idiopathic dilated cardiomyopathy. From each heart left (LV) and right ventricular (RV) myocardial samples were analyzed by Affymetrix HG-U133 Plus 2.0 arrays, adding up to six sample groups. Unsupervised cluster analyses of the six sample groups revealed a clear separation of NF and cardiomyopathy samples. However, in contrast to the other samples, unsupervised cluster analyses revealed no distinct expression pattern in LV and RV samples from ARVC-hearts. We further identified differentially expressed transcripts using t-tests and found transcripts separating diseased and NF ventricular myocardium. Of note, in failing myocardium only about 15-16% of the genes are commonly regulated compared to NF samples. In addition both cardiomyopathies are clearly distinct on the transcriptome level. Comparison of the expression patterns between the failing RV and LV using a paired t-test revealed a lack of major differences between LV and RV gene expression in ARVC hearts. Microarrays were used to elucidate the differences between non-failing control hearts and those, suffering from arrhythmogenic right ventricular cardiomyopathy (ARVC).
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:Analysis of left venticular myocardium following morphine-induced sustained ligand activated preconditioning (SLP). Results provide insight into the molecular pathways affected by morphine-induced SLP in the pre- and post-ischemic heart.