Project description:ABSTRACT Background: Viral myocarditis is a life-threatening illness that may lead to heart failure or cardiac arrhythmias. This study examined whether human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) could be used to model the pathogenic processes of coxsackievirus-induced viral myocarditis and to screen antiviral therapeutics for efficacy. Methods and Results: Human iPSC-CMs were infected with a luciferase-expressing mutant of the coxsackievirus B3 strain (CVB3-Luc). Brightfield microscopy, immunofluorescence, and calcium imaging were used to characterize virally infected hiPSC-CMs. Viral proliferation on hiPSC-CMs was subsequently quantified using bioluminescence imaging. For drug screening, select antiviral compounds including interferon beta 1 (IFNβ1), ribavirin, pyrrolidine dithiocarbamate (PDTC), and fluoxetine were tested for their capacity to abrogate CVB3-Luc proliferation in hiPSC-CMs in vitro. The ability of some of these compounds to reduce CVB3-Luc proliferation in hiPSC-CMs was consistent with the reported drug effects in previous studies. Finally, mechanistic analyses via gene expression profiling of hiPSC-CMs infected with CVB3-Luc revealed an activation of viral RNA and protein clearance pathways within these hiPSC-CMs after IFNβ1 treatment. Conclusions: This study demonstrates that hiPSC-CMs express the coxsackievirus and adenovirus receptor, are susceptible to coxsackievirus infection, and can be used to confirm antiviral drug efficacy. Our results suggest that the hiPSC-CM/CVB3-Luc assay is a sensitive platform that could be used to screen novel antiviral therapeutics for their effectiveness in a high-throughput fashion. For this experiment, human induced pluripotent stem cell derived cardiomyocytes were infected with coxsackievirus at multiplicity of infection (MOI) of 5 for 8 hours. Cells were treated with and without interferon beta 1 in order to determine if treatment activates antiviral response genes and/or viral clearance pathways. 4 total samples (2 for each condition) were analyzed
Project description:Analysis of the microRNA profile exression in hiPSC-CMs. Results provide important information of the miRNAs expressed in hiPSC-CMs under control conditions.
Project description:We describe a combination of methods to induce a more mature phenotype in hiPSC-CMs. RNA-seq analysis was performed to compare gene expression between hiPSC-CMs cultured under standard conditions (GLUC) and those cultured under semi optimized (MM) and fully optimized (MPAT) conditions
Project description:Mitochondria play a crucial role in the differentiation and maturation of human cardiomyocytes (CMs). To identify mitochondrial pathways and regulators that are involved in cardiac differentiation and maturation, we examined human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Proteomic analysis was performed on enriched mitochondrial protein extracts isolated from hiPSC-CMs differentiated from dermal fibroblasts (dFCM) and cardiac fibroblasts (cFCM), at different days of differentiation (between 12 and 115 days), and also from adult and neonatal mouse hearts for comparison. Mitochondrial proteins with a ≥2-fold change between differentiation time points in dFCMs and cFCMs, and between adult versus neonatal mouse hearts, were subjected to Ingenuity Pathway Analysis (IPA), and some upregulated proteins were validated by immunoblotting. The highest significant upregulation was in metabolic pathways for fatty acid oxidation (FAO), the tricarboxylic acid (TCA) cycle, oxidative phosphorylation (OXPHOS) and branched chain amino acid (BCAA) catabolism. The top upstream regulators predicted by IPA were- peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1-a), the insulin receptor and the retinoblastoma protein (Rb) transcriptional repressor. In addition, IPA and immunoblotting showed substantial upregulation of the mitochondrial LonP1 protease, which regulates mitochondrial proteostasis, energetics and metabolism. Using this proteomics approach, we have identified key metabolic and intracellular signaling pathways that are up- and down- regulated during the biogenesis of mitochondria in differentiating and maturing cardiac myocytes.
Project description:In this study, we investigated the effects of ethanol exposure on cardiomyocyte differentiation by treating the cells with various concentrations of ethanol. The results indicated that ethanol exposure during hiPSC-CM differentiation reduced cell viability, cell proliferation, and cardiomyocyte yield, and caused mitochondrial dysfunction, redox imbalance, and changes of proteomic profiles.
Project description:Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are commonly used to model arrhythmogenic cardiomyopathy (ACM), a heritable cardiac disease characterized by severe ventricular arrhythmias, fibrofatty myocardial replacement and progressive ventricular dysfunction. Although ACM is inherited as an autosomal dominant disease, incomplete penetrance and variable expressivity are extremely common, resulting in different clinical manifestations. Here, we propose hiPSC-CMs as a powerful in vitro model to study incomplete penetrance in ACM. Six hiPSC lines were generated from blood samples of three ACM patients carrying a heterozygous deletion of exon 4 in the PKP2 gene, two asymptomatic (ASY) carriers of the same mutation and one healthy control (CTR), all belonging to the same family. Whole exome sequencing was performed in all family members and hiPSC-CMs were examined by ddPCR, western blot, Wes™ immunoassay system, patch clamp, immunofluorescence and RNASeq. Our results show molecular and functional differences between ACM and ASY hiPSC_x0002_CMs, including a higher amount of mutated PKP2 mRNA, a lower expression of the connexin-43 protein, a lower overall density of sodium current, a higher intracellular lipid accumulation and sarcomere disorganization in ACM compared to ASY hiPSC_x0002_CMs. Differentially expressed genes were also found, supporting a predisposition for a fatty phenotype in ACM hiPSC-CMs. These data indicate that hiPSC-CMs are a suitable model to study incomplete penetrance in ACM.
Project description:Methods: RNA-seq libraries were prepared using the Illumina TruSeq RNA kit and the TrueSeq method was employed for mRNA enrichment. The libraries were quantified and samples were multiplexed in each lane of the flowcell. Cluster generation was performed and then sequenced on the Illumina HiSeq2500 system. Reads were mapped on the Human Genome Reference and normalized expression table was generated. Results: RNA-seq results reveal gene expression of cardiac toxicity in hiPSC-CMs that are consistent with alcohol-induced pathophysiology observed in animal models. For example MMP9 is among the top 5 upregulated genes in ethanol-treated hiPSC-CMs, MMP9 concentrations are significantly higher in human sera of chronic alcohol abusers and MMP9 mRNA and protein levels are increased in the myocardium of rats following acute ethanol exposure. Conclusions: Data demonstrate significant alteration in gene expression, among the top 60 genes significantly altered by ethanol exposure, 8 genes are involved in ion channels, which may be in part contributing to the abnormal intracellular Ca2+ transients. Ethanol up-regulated the expression of genes associated with collagen metabolism and extracellular matrix (MMP9, EMID1, COL14A1), most of the downregulated genes are involved in cardiovascular system development (NPPB, DNAAF3), actin filament-based process (LMOD2, MYH4) and muscle contraction (MYL2). These findings are consistent with previous studies showing a correlation between alcohol exposure and defects in heart and circulatory system development.
Project description:Chronic alcohol consumption in adults can induce cardiomyopathy, arrhythmias, and heart failure. In newborns, prenatal alcohol exposure can increase the risk of congenital heart diseases. Understanding biological mechanisms involved in the long-term alcohol exposure-induced cardiotoxicity is pivotal to the discovery of therapeutic strategies. In this study, cardiomyocytes derived from human pluripotent stem cells (hiPSC-CMs) were treated with clinically relevant doses of ethanol for various durations up to 5 weeks. The treated cells were characterized for their cellular properties and functions, and global proteomic profiling was conducted to understand the molecular changes associated with long-term ethanol exposure. Increased cell death, oxidative stress, deranged Ca2+ handling, abnormal action potential, altered contractility, and suppressed structure development were observed in ethanol-treated cells. Many dysregulated proteins identified by global proteomic profiling were involved in apoptosis, heart contraction, and extracellular collagen matrix. In addition, several signaling pathways including the Wnt and TGFβ signaling pathways were affected due to long-term ethanol treatment. Therefore, chronic ethanol treatment of hiPSC-CMs induces cardiotoxicity, impairs cardiac functions, and alters protein expression and signaling pathways. This study demonstrates the utility of hiPSC-CMs as a novel model for chronic alcohol exposure study and provides the molecular mechanisms associated with long-term alcohol exposure in human cardiomyocytes.