Proteomic Analysis of Human Pluripotent Stem Cell–Derived, Fetal, and Adult Ventricular Cardiomyocytes Reveals Pathways Crucial for Cardiac Metabolism and Maturation

Abstract

Background-Differentiation of pluripotent human embryonic stem cells (hESCs) to the cardiac lineage represents a potentially unlimited source of ventricular cardiomyocytes (VCMs), but hESC-VCMs are developmentally immature. Previous attempts to profile hESC-VCMs primarily relied on transcriptomic approaches, but the global proteome has not been examined. Furthermore, most hESC-CM studies focus on pathways important for cardiac differentiation, rather than regulatory mechanisms for CM maturation. We hypothesized that gene products and pathways crucial for maturation can be identified by comparing the proteomes of hESCs, hESC-derived VCMs, human fetal and human adult ventricular and atrial CMs. Methods and Results-Using two-dimensional-differential-in-gel electrophoresis, 121 differentially expressed (>1.5-fold; P<0.05) proteins were detected. The data set implicated a role of the peroxisome proliferator-activated receptor α signaling in cardiac maturation. Consistently, WY-14643, a peroxisome proliferator-activated receptor α agonist, increased fatty oxidative enzyme level, hyperpolarized mitochondrial membrane potential and induced a more organized morphology. Along this line, treatment with the thyroid hormone triiodothyronine increased the dynamic tension developed in engineered human ventricular cardiac microtissue by 3-fold, signifying their maturation. Conclusions-We conclude that the peroxisome proliferator-activated receptor α and thyroid hormone pathways modulate the metabolism and maturation of hESC-VCMs and their engineered tissue constructs. These results may lead to mechanism-based methods for deriving mature chamber-specific CMs.

Maturation of human induced pluripotent stem cell-derived cardiomyocytes for modeling hypertrophic cardiomyopathy

“…hiPSC-CMs offer a number of additional benefits, including scalability, the ability to generate patientspecific cells, and quickly create knockout and transgenic lines via CRISPR/Cas9mediated gene editing. In spite of these benefits, hiPSC-CMs possess a significant drawback-they are functionally immature, and typically resemble fetal or neonatal cardiomyocytes in terms of cell size and morphology, gene expression, myofibril contractility, and metabolic activity [1][2][3][4] . While certain forms of cardiovascular disease, such as congenital heart defects and cardiomyopathies caused by homozygous or compound heterozygous mutations, do primarily affect infants, most forms of pathological cardiac remodeling are diseases that afflict adults.…”

Impaired Regulation of Redox Transcriptome during the Differentiation of iPSCs into Induced Cardiomyocytes (iCMs)

“…For a better understanding of the redox status of iCMs, we performed genomic and bioinformatics analyses in human iPS (hiPS) and hiPS-derived cardiomyocytes (hiPS-iCM) to identify novel genes and pathways that are associated with the redox transcriptome. Most of the published reports focused mainly on analyzing the pathways involved in reprogramming, differentiation, maturation and metabolic signaling of induced cardiomyocytes (1, 2, 8, 21, 22). Outcomes of these transcriptome analyses included genes that are dramatically changed (differential expression >50 fold) in iCM versus iPS cells, but ignored several thousands of genes that are significantly changed at >2.0 to 20 fold resulting in masking the significance of several other key pathways during differentiation.…”

Induced pluripotent stem cell-derived cardiomyocytes: A platform for testing for drug cardiotoxicity

“…Fetal cardiomyoctes utilize glucose for energy production via anaerobic glycolysis, in contrast to the mature heart which utilizes fatty acids via beta oxidation (27; 28). Immature hiPSC-CMs utilizing glucose could result in erroneous results when studying a drug which has its mechanism of action through alterations in fatty acid metabolism or mitochondrial function.…”