Patterning myocardial specification of human pluripotent stem cells

项目总结/摘要 人多能干细胞（hPSC）来源于胚胎或转录因子诱导的起源。 在受控条件下，它们在体外重演心脏发育，并产生 所有亚型。新生心肌细胞是人类心肌细胞的最佳替代物， 发现、心脏毒性筛查和心脏细胞替代疗法。然而，目前的技术 从hPSC衍生心肌细胞对于实现所述的转化目标具有主要障碍。一 主要的问题是异质性;在给定的批次中，衍生的心肌细胞是不加选择的混合物， 心肌细胞的所有主要亚型，即，结、心房和心室。没有细胞治疗，毒性筛选和 药物发现可以在培养皿中具有不确定的心肌细胞亚群。我们建议 通过将心脏发育过程中最有效的信号之一施加于心肌细胞来解决这个问题 在hPSC分化过程中形成图案。我们假设视黄酸（RA）信号引导hPSC向 向第一心野的心室或心房心肌细胞的离散群体分化。我们 初步数据表明，RA信号传导的时间和剂量依赖性操纵导致富集的 来自hESC和hiPSC的心房或心室心肌细胞群。此外，心脏 室特异性心肌细胞在其电激发和机械刺激方面是功能上可区分的。 收缩。我们将建立在我们的初步观察，以发现一个强大的和可推广的信号轴， 获得具有天然心室的基因型和表型标志的心腔特异性肌细胞， 心房肌细胞成功完成此提案将有助于了解女性与男性的关系 hiPS细胞的心原性潜力的差异和心脏腔室特异性疾病建模的保真度。

Project Summary/Abstract Human pluripotent stem cells (hPSCs) originate from either embryonic or transcription factor-induced origins. Under controlled conditions, they recapitulate cardiac development in vitro and give rise to cardiac myocytes of all subtypes. The de novo cardiac myocytes are the best surrogate for human cardiomyocytes for drug discovery, cardiotoxicity screen and cardiac cell replacement therapies. However, present technology for deriving cardiac myocytes from hPSCs has major hurdles to clear toward the stated translational goals. One major problem is heterogeneity; in a given batch, the derived cardiac myocytes are an indiscriminate blend of all major subtypes of cardiomyocytes, i.e., nodal, atrial and ventricular. No cell therapy, toxicity screen and drug discovery can afford to have undefined sub-populations of cardiac myocytes in a dish. We propose to solve this problem by imposing one of the most potent signals during cardiac development on cardiac myocyte patterning during hPSC differentiation. We hypothesize that retinoic acid (RA) signaling steers hPSCs to differentiate toward discrete populations of ventricular or atrial cardiomyocytes of the first heart field. Our preliminary data indicate that temporal and dose dependent manipulation of RA signaling leads to enriched populations of atrial or ventricular cardiomyocytes from hESCs and hiPSCs. Furthermore, the cardiac chamber-specific cardiomyocytes are functionally distinguishable in their electrical excitation and mechanical contraction. We will build on our initial observations to discover a robust and generalizable signaling axis to attain cardiac chamber-specific myocytes with genotypic and phenotypic hallmarks of the native ventricular and atrial myocytes. Successful completion of this proposal will lead to understanding of female vs. male differences in cardiogenic potential of hiPS cells and the fidelity of cardiac chamber-specific disease modeling.