Gene expression and chromatin organization changes in lamin A/C haploinsufficient human induced pluripotent stem cell-derived cardiomyocytes
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE126460 | GEO | 2019/02/13
REPOSITORIES: GEO
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Project description:Pathogenic mutations in A-type nuclear lamins may dysregulate gene expression due to changes in chromatin organization into active (A) and inactive (B) compartments. To test this, we performed genome-wide chromosome conformation analyses (Hi-C) and transcriptome profiling (RNA-seq) in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) with a haploinsufficient mutation for Lamin A/C that causes cardiac laminopathy. Mutant hiPSC-CM have marked electrophysiological, contractile, and gene expression alterations. While large-scale changes in chromatin topology are evident, differences in chromatin compartmentalization are limited to a few hotspots. These regions normally transition from A to B during cardiogenesis, but remain in A in mutant hiPSC-CM. Non-cardiac genes located within such aberrant domains are ectopically expressed, including the neuronal P/Q-type calcium channel CACNA1A. Pharmacological inhibition of the resulting currents partially mitigates elongation of field potential duration in mutant hiPSC-CM. On the other hand, A/B compartment changes do not explain most gene expression alterations observed in mutant hiPSC-CM, putting in perspective the role of chromatin organization dysregulation in cardiac laminopathy.
2019-02-13 | GSE126459 | GEO
Project description:Pathogenic mutations in A-type nuclear lamins may dysregulate gene expression due to changes in chromatin organization into active (A) and inactive (B) compartments. To test this, we performed genome-wide chromosome conformation analyses (Hi-C) and transcriptome profiling (RNA-seq) in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) with a haploinsufficient mutation for Lamin A/C that causes cardiac laminopathy. Mutant hiPSC-CM have marked electrophysiological, contractile, and gene expression alterations. While large-scale changes in chromatin topology are evident, differences in chromatin compartmentalization are limited to a few hotspots. These regions normally transition from A to B during cardiogenesis, but remain in A in mutant hiPSC-CM. Non-cardiac genes located within such aberrant domains are ectopically expressed, including the neuronal P/Q-type calcium channel CACNA1A. Pharmacological inhibition of the resulting currents partially mitigates elongation of field potential duration in mutant hiPSC-CM. On the other hand, A/B compartment changes do not explain most gene expression alterations observed in mutant hiPSC-CM, putting in perspective the role of chromatin organization dysregulation in cardiac laminopathy.
2019-02-13 | GSE126458 | GEO
Project description:Gene expression and chromatin organization changes in lamin A/C haploinsufficient human induced pluripotent stem cell-derived cardiomyocytes
| PRJNA521975 | ENA
Project description:BackgroundPrevious studies proposed that throughout differentiation of human induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CMs), only 3 types of action potentials (APs) exist: nodal-, atrial-, and ventricular-like.ObjectivesTo investigate whether there are precisely 3 phenotypes or a continuum exists among them, we tested 2 hypotheses: (1) During culture development a cardiac precursor cell is present that-depending on age-can evolve into the 3 phenotypes. (2) The predominant pattern is early prevalence of a nodal phenotype, transient appearance of an atrial phenotype, evolution to a ventricular phenotype, and persistence of transitional phenotypes.MethodsTo test these hypotheses, we (1) performed fluorescence-activated cell sorting analysis of nodal, atrial, and ventricular markers; (2) recorded APs from 280 7- to 95-day-old iPSC-CMs; and (3) analyzed AP characteristics.ResultsThe major findings were as follows: (1) fluorescence-activated cell sorting analysis of 30- and 60-day-old cultures showed that an iPSC-CMs population shifts from the nodal to the atrial/ventricular phenotype while including significant transitional populations; (2) the AP population did not consist of 3 phenotypes; (3) culture aging was associated with a shift from nodal to ventricular dominance, with a transient (57-70 days) appearance of the atrial phenotype; and (4) beat rate variability was more prominent in nodal than in ventricular cardiomyocytes, while pacemaker current density increased in older cultures.ConclusionFrom the onset of development in culture, the iPSC-CMs population includes nodal, atrial, and ventricular APs and a broad spectrum of transitional phenotypes. The most readily distinguishable phenotype is atrial, which appears only transiently yet dominates at 57-70 days of evolution.
| S-EPMC5421365 | biostudies-literature
Project description:Gene expression and chromatin organization changes in lamin A/C haploinsufficient human induced pluripotent stem cell-derived cardiomyocytes [Hi-C]
| PRJNA521978 | ENA
Project description:Gene expression and chromatin organization changes in lamin A/C haploinsufficient human induced pluripotent stem cell-derived cardiomyocytes [RNA-seq]
| PRJNA521977 | ENA
Project description:Engineering of myocardial tissue constructs is a promising approach for treatment of coronary heart disease. To engineer myocardial tissues that better mimic the highly ordered physiological arrangement and function of native cardiomyocytes, we generated electrospun microfibrous polycaprolactone scaffolds with either randomly oriented (14 ?m fiber diameter) or parallel-aligned (7 ?m fiber diameter) microfiber arrangement and co-seeded the scaffolds with human induced pluripotent stem cell-derived cardiomyocytes (iCMs) and endothelial cells (iECs) for up to 12 days after iCM seeding. Here we demonstrated that aligned microfibrous scaffolds induced iCM alignment along the direction of the aligned microfibers after 2 days of iCM seeding, as well as promoted greater iCM maturation by increasing the sarcomeric length and gene expression of myosin heavy chain adult isoform (MYH7), in comparison to randomly oriented scaffolds. Furthermore, the benefit of scaffold anisotropy was evident in the significantly higher maximum contraction velocity of iCMs on the aligned scaffolds, compared to randomly oriented scaffolds, at 12 days of culture. Co-seeding of iCMs with iECs led to reduced contractility, compared to when iCMs were seeded alone. These findings demonstrate a dominant role of scaffold anisotropy in engineering cardiovascular tissues that maintain iCM organization and contractile function.
| S-EPMC5567776 | biostudies-literature
Project description:Human induced pluripotent stem (iPS) cells hold great promise for cardiovascular research and therapeutic applications, but the ability of human iPS cells to differentiate into functional cardiomyocytes has not yet been demonstrated. The aim of this study was to characterize the cardiac differentiation potential of human iPS cells generated using OCT4, SOX2, NANOG, and LIN28 transgenes compared to human embryonic stem (ES) cells. The iPS and ES cells were differentiated using the embryoid body (EB) method. The time course of developing contracting EBs was comparable for the iPS and ES cell lines, although the absolute percentages of contracting EBs differed. RT-PCR analyses of iPS and ES cell-derived cardiomyocytes demonstrated similar cardiac gene expression patterns. The pluripotency genes OCT4 and NANOG were downregulated with cardiac differentiation, but the downregulation was blunted in the iPS cell lines because of residual transgene expression. Proliferation of iPS and ES cell-derived cardiomyocytes based on 5-bromodeoxyuridine labeling was similar, and immunocytochemistry of isolated cardiomyocytes revealed indistinguishable sarcomeric organizations. Electrophysiology studies indicated that iPS cells have a capacity like ES cells for differentiation into nodal-, atrial-, and ventricular-like phenotypes based on action potential characteristics. Both iPS and ES cell-derived cardiomyocytes exhibited responsiveness to beta-adrenergic stimulation manifest by an increase in spontaneous rate and a decrease in action potential duration. We conclude that human iPS cells can differentiate into functional cardiomyocytes, and thus iPS cells are a viable option as an autologous cell source for cardiac repair and a powerful tool for cardiovascular research.
| S-EPMC2741334 | biostudies-literature
Project description:RationaleCardiomyocytes generated from human induced pluripotent stem cells (hiPSCs) are suggested as the most promising candidate to replenish cardiomyocyte loss in regenerative medicine. Little is known about their calcium homeostasis, the key process underlying excitation-contraction coupling.ObjectiveWe investigated the calcium handling properties of hiPSC-derived cardiomyocytes and compared with those from human embryonic stem cells (hESCs).Methods and resultsWe differentiated cardiomyocytes from hiPSCs (IMR90 and KS1) and hESCs (H7 and HES3) with established protocols. Beating outgrowths from embryoid bodies were typically observed 2 weeks after induction. Cells in these outgrowths were stained positively for tropomyosin and sarcomeric alpha-actinin. Reverse-transcription polymerase chain reaction studies demonstrated the expressions of cardiac-specific markers in both hiPSC- and hESC-derived cardiomyocytes. Calcium handling properties of 20-day-old hiPSC- and hESC-derived cardiomyocytes were investigated using fluorescence confocal microscopy. Compared with hESC-derived cardiomyocytes, spontaneous calcium transients from both lines of hiPSC-derived cardiomyocytes were of significantly smaller amplitude and with slower maximal upstroke velocity. Better caffeine-induced calcium handling kinetics in hESC-CMs indicates a higher sacroplasmic recticulum calcium store. Furthermore, in contrast with hESC-derived cardiomyocytes, ryanodine did not reduce the amplitudes, maximal upstroke and decay velocity of calcium transients of hiPSC-derived cardiomyocytes. In addition, spatial inhomogeneity in temporal properties of calcium transients across the width of cardiomyocytes was more pronounced in hiPSC-derived cardiomyocytes than their hESC counterpart as revealed line-scan calcium imaging. Expressions of the key calcium-handling proteins including ryanodine recptor-2 (RyR2), sacroplasmic recticulum calcium-ATPase (SERCA), junction (Jun) and triadin (TRDN), were significantly lower in hiPSC than in hESCs.ConclusionsThe results indicate the calcium handling properties of hiPSC-derived cardiomyocytes are relatively immature to hESC counterparts.
| S-EPMC3226695 | biostudies-literature
Project description:BackgroundThe ability to establish human induced pluripotent stem cells (hiPSCs) by reprogramming of adult fibroblasts and to coax their differentiation into cardiomyocytes opens unique opportunities for cardiovascular regenerative and personalized medicine. In the current study, we investigated the Ca(2+)-handling properties of hiPSCs derived-cardiomyocytes (hiPSC-CMs).Methodology/principal findingsRT-PCR and immunocytochemistry experiments identified the expression of key Ca(2+)-handling proteins. Detailed laser confocal Ca(2+) imaging demonstrated spontaneous whole-cell [Ca(2+)](i) transients. These transients required Ca(2+) influx via L-type Ca(2+) channels, as demonstrated by their elimination in the absence of extracellular Ca(2+) or by administration of the L-type Ca(2+) channel blocker nifedipine. The presence of a functional ryanodine receptor (RyR)-mediated sarcoplasmic reticulum (SR) Ca(2+) store, contributing to [Ca(2+)](i) transients, was established by application of caffeine (triggering a rapid increase in cytosolic Ca(2+)) and ryanodine (decreasing [Ca(2+)](i)). Similarly, the importance of Ca(2+) reuptake into the SR via the SR Ca(2+) ATPase (SERCA) pump was demonstrated by the inhibiting effect of its blocker (thapsigargin), which led to [Ca(2+)](i) transients elimination. Finally, the presence of an IP3-releasable Ca(2+) pool in hiPSC-CMs and its contribution to whole-cell [Ca(2+)](i) transients was demonstrated by the inhibitory effects induced by the IP3-receptor blocker 2-Aminoethoxydiphenyl borate (2-APB) and the phospholipase C inhibitor U73122.Conclusions/significanceOur study establishes the presence of a functional, SERCA-sequestering, RyR-mediated SR Ca(2+) store in hiPSC-CMs. Furthermore, it demonstrates the dependency of whole-cell [Ca(2+)](i) transients in hiPSC-CMs on both sarcolemmal Ca(2+) entry via L-type Ca(2+) channels and intracellular store Ca(2+) release.
| S-EPMC3069979 | biostudies-literature