Project description:Background Anticancer therapies have significantly improved patient outcomes; however, cardiac side effects from cancer therapies remain a significant challenge. Cardiotoxicity following treatment with proteasome inhibitors such as carfilzomib is known in clinical settings, but the underlying mechanisms have not been fully elucidated. Methods and Results Using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) as a cell model for drug-induced cytotoxicity in combination with traction force microscopy, functional assessments, high-throughput imaging, and comprehensive omic analyses, we examined the molecular mechanisms involved in structural and functional alterations induced by carfilzomib in hiPSC-CMs. Following the treatment of hiPSC-CMs with carfilzomib at 0.01 to 10 µmol/L, we observed a concentration-dependent increase in carfilzomib-induced toxicity and corresponding morphological, structural, and functional changes. Carfilzomib treatment reduced mitochondrial membrane potential, ATP production, and mitochondrial oxidative respiration and increased mitochondrial oxidative stress. In addition, carfilzomib treatment affected contractility of hiPSC-CMs in 3-dimensional microtissues. At a single cell level, carfilzomib treatment impaired Ca2+ transients and reduced integrin-mediated traction forces as detected by piconewton tension sensors. Transcriptomic and proteomic analyses revealed that carfilzomib treatment downregulated the expression of genes involved in extracellular matrices, integrin complex, and cardiac contraction, and upregulated stress responsive proteins including heat shock proteins. Conclusions Carfilzomib treatment causes deleterious changes in cellular and functional characteristics of hiPSC-CMs. Insights into these changes could be gained from the changes in the expression of genes and proteins identified from our omic analyses.
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: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:Drug-induced cardiotoxicity is a widespread clinical issue affecting numerous drug classes and remains difficult to treat. One such drug class is Tyrosine Kinase Inhibitors (TKIs), which cause varying degrees of contraction-related cardiotoxicity usually after weeks of exposure. Understanding molecular mechanisms underlying both acute and chronic toxicity of TKIs could help identify new treatment opportunities. Here, we presented transcriptome responses to four TKIs (Sunitinib, Sorafenib, Lapatinib and Erlotinib) across 3 doses and 4 time points in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Gene expression evolved continually under drug treatment and revealed changes in several biological networks that were associated with cardiac metabolism and contraction. These changes were confirmed by proteomics and resulted in metabolic and structural remodeling of hiPSC-CMs. One of the metabolic remodeling was the increased aerobic glycolysis induced by Sorafenib, which is an adaptive response in preserving cell survival under Sorafenib treatment. Drug adaptation in cardiac cells may represent new targets for managing chronic forms of TKI-induced cardiotoxicity.
Project description:The effect of cyclic mechanical stretch (0.5 Hz, 10-21% elongation) on gene expression of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) was studied using RNA sequencing.
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.