Project description:Cardiomyopathies are heart muscle disorders characterised by chamber dilation often accompanied by wall thinning, severe systolic and diastolic dysfunction and frequently heart failure. Although several genes were found to be differentially expressed the cellular and molecular basis of the disease still remains poorly understood. We performed expression profiling on cardiac samples from six different mouse disease models: muscle LIM protein- (MLP), ErbB2-, ErbB4- and plakoglobin-deficient mice, doxorubicin treated mice and doxorubicin treated ErbB4 deficient mice. We aimed at the identification of general cardiomyopathy expression patterns as well as mouse model specific ones. Keywords: expression profiling, mouse models for cardiomyopathy
Project description:SARS-CoV2 infection leads to cardiac injury and dysfunction in 20-30% of hospitalized patients and higher rates of mortality in patients with pre-existing cardiovascular disease. Inflammatory factors released as part of the 'cytokine storm' are thought to play a critical role in cardiac dysfunction in severe COVID-19 patients. Here we use human cardiac organoid technology combined with high sensitivity phosphoproteomics and single nuclei RNA sequencing to identify inflammatory targets inducing cardiac dysfunction. This new pipeline allowed rapid progress and identification of putative therapeutics. We identify a novel interferon-gamma driven BRD4 (bromodomain protein 4)-fibrosis/iNOS axis as a key intracellular mediator of inflammation-induced cardiac dysfunction. This axis is therapeutically targetable using BRD4 inhibitors, which promoted full recovery of function in human cardiac organoids and prevented severe inflammation and death in a cytokine-storm mouse model. The BRD inhibitor INCB054329 was the most efficacious, and is a prime candidate for drug repurposing to attenuate cardiac dysfunction and improve COVID-19 mortality in humans.
Project description:Heart disease is the leading cause of death in the developed world, and its comorbidities such as hypertension, diabetes, and heart failure are accompanied by major transcriptomic changes in the heart. During cardiac dysfunction, which leads to heart failure, there are global epigenetic alterations to chromatin that occur concomitantly with morphological changes in the heart in response to acute and chronic stress. These epigenetic alterations include the reversible methylation of lysine residues on histone proteins. Lysine methylation on histone H3K4 and H3K9 were among the first methylated lysine residues identified and have been linked to gene activation and silencing, respectively. However, much less is known regarding other methylated histone residues, including histone H4K20. Trimethylation of histone H4K20 has been shown to repressive gene expression, however this mark has never been examined in the heart. Here we utilized immunoblotting and mass spectrometry to quantify histone H4K20 trimethylation in three models of cardiac dysfunction. Our results show that lysine methylation at this site is regulated in a biphasic manner leading to increased H420 trimethylation during acute hypertrophic stress and decreased H4K20 trimethylation during sustained ischemic injury and cardiac dysfunction. In addition, we examined publicly available datasets to analyze enzymes that regulate H4K20 methylation and identified one demethylase (KDM7C) and two methyltransferases (KMT5A and SMYD5) which were all upregulated in heart failure patients. This is the first study to examine histone H4K20 trimethylation in the heart and to determine how this post-translational modification is differentially regulated in multiple models of cardiac disease.
Project description:We used microarrays to detail genome-wide gene expression underlying cardiac myocyte pathologies and identified candidate genes and specific pathways affecting cardiac myopathies Keywords: transgenics, cardiac disease analysis Mouse heart atria were dissected for RNA extraction and hybridisation on Affymetrix microarrays. We sought to profile gene expression from the transgenic mouse models for non-transgenics (Ntg), dnPI3K (dominant negative for phosphoinositide 3-kinase), Mst1 (mammalian sterile 20-like kinase 1) and dnPI3K-Mst1 (double mutant) mouse models with a combined background of C57BL/6/FVB/N inbred strains. Pathological insults on cardiac myocytes are investigated
Project description:Mutations in Nkx2-5 are a main cause of cardiac congenital heart disease. Here we describe a new Nkx2-5 point-mutation murine model, akin to its human counterpart disease generating mutation. Our model fully reproduces the morphological and physiological clinical presentations of the disease and reveals an under-studied aspect of Nkx2-5 driven pathology, a primary right ventricular dysfunction. We further describe the molecular consequences of disrupting the transcriptional network regulated by Nkx2-5 in the heart and show that Nkx2-5 dependent perturbation of the Wnt signaling pathway promotes heart dysfunction through alteration of cardiomyocyte metabolism. Our data provide mechanistic insights on how Nkx2-5 regulates heart function and metabolism, a novel link in the study of congenital heart disease, and confirms that our models are the first murine genetic models to present all spectra of clinically relevant congenital heart disease phenotypes generated by Nkx2-5 mutations in patients.
Project description:Background: The insulin/IGF/relaxin family represents a group of structurally related but functionally diverse proteins. The family member Relaxin-2 has been evaluated in clinical trials for its efficacy in the treatment of acute heart failure. In this study, we assessed the role of Insulin-like peptide 6 (Insl6), another member of this protein family, in murine heart failure models using genetic loss-of-function and protein delivery methods. Methods and Results: Insl6-deficient (Insl6-KO) and wild-type (C57BL/6N) mice were administered angiotensin II or isoproterenol via continuous infusion with an osmotic pump or via intraperitoneal injection once a day, respectively for 2 weeks. In both models, Insl6-KO mice exhibited greater cardiac systolic dysfunction and left ventricular dilatation hypertrophy. Cardiac dysfunction in the Insl6-KO mice was associated with more extensive cardiac fibrosis and greater expression of fibrosis-associated genes. The continuous infusion of chemically synthesized INSL6 significantly attenuated left ventricular systolic dysfunction and cardiac fibrosis induced by isoproterenol infusion. Gene expression profiling suggests Lxr/ Rxr signaling is activated in the isoproterenol-challenged hearts treated with INSL6 protein. Conclusions: Endogenous Insl6 protein inhibits cardiac systolic dysfunction and cardiac fibrosis in angiotensin II- and isoproterenol-induced cardiac stress models. The administration of recombinant Insl6 protein could have utility for the treatment of heart failure and cardiac fibrosis.
Project description:In the current study we examined several proteomic- and RNA-Seq-based datasets of cardiac-enriched, cell-surface and membrane-associated proteins in human fetal and mouse neonatal ventricular cardiomyocytes. By integrating available microarray and tissue expression profiles along with MGI phenotypic analysis, we identified 173 membrane-associated proteins that are cardiac-enriched, conserved amongst eukaryotic species, and have not yet been linked to a ‘cardiac’ Phenotype-Ontology. To highlight the utility of this dataset, we selected several proteins to investigate more carefully, including FAM162A, MCT1, and COX20, to show cardiac enrichment, subcellular distribution and expression patterns in disease. Three-dimensional imaging was used to validate subcellular localization and expression in adult mouse ventricular cardiomyocytes. FAM162A, MCT1, and COX20 were differentially expressed at the transcriptomic and proteomic levels in multiple models of mouse and human heart diseases and may represent potential diagnostic and therapeutic targets for human dilated and ischemic cardiomyopathies. Altogether, we believe this comprehensive cardiomyocyte membrane proteome dataset will prove instrumental to future investigations aimed at characterizing heart disease markers and/or therapeutic targets for heart failure.
Project description:Comprehensive knowledge of the dynamic changes in the cardiac transciptome can inform disease mechanism. Previous transcriptome profiling studies on heart failure rely on either microarray or RNA-Seq with low coverage, leaving a large portion of the transcriptome unexplored. Additionally, previous studies only examined two end stages of the disease, onset and late-stage heart failure. Profile of the transcriptome in the middle stage of disease progression can reveal critical molecular events underlying disease transition. Towards these goals, we conducted a multi-factorial RNA-Seq experiment, comparing the dynamic changes in the transcriptome of two murine models of heart failure, pressure overload and loss of mitochondrial complex I. Our data represents the deepest transcriptome coverage to date, covering onset, progression, and late stage of the disease. We found extensive differences in the expression magnitude and dynamics of the transciptomes in different heart failure models. In addition, such differences are associated with progressive worsening of cardiac physiology. Our analysis revealed that mitochondrial dysfunction combined with stress leads to increased number of differentially expressed long intergenic noncoding RNAs, including a recently identified lincRNA that is a master regulator of the cardiac lineage during development.