Patterning myocardial specification of human pluripotent stem cells

项目摘要/摘要 人类多能干细胞(HPSCs)来源于胚胎或转录因子诱导的来源。 在受控条件下，它们概括了体外心脏的发育情况，并产生了 所有子类型。新生心肌细胞是人类心肌细胞药物的最佳替代物 发现、心脏毒性筛选和心脏细胞替代疗法。然而，目前的技术用于 从hPSCs中提取心肌细胞要达到既定的翻译目标有很大的障碍。一 主要问题是异质性；在给定的批次中，衍生的心肌细胞是不分青红皂白的 所有主要的心肌细胞亚型，即交界性、房性和室性。没有细胞治疗，毒性筛查和 药物发现可以承受在培养皿中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到心肌细胞来解决这个问题 HPSC分化过程中的图案化。我们假设维甲酸(RA)信号引导hPSCs 分化为第一心野的心室或心房心肌细胞的离散群体。我们的 初步数据表明，RA信号的时间和剂量依赖的操作导致丰富 HESCs和hPSCs的心房或心室心肌细胞群。此外，心脏 特定于室壁的心肌细胞在电兴奋和机械兴奋方面是可以区分的 收缩。我们将以我们最初的观察为基础，发现一个健壮且可推广的信号轴 获得具有天然心脏和心脏的基因和表型特征的心腔特异的心肌细胞 心房肌细胞。成功完成这项建议将导致对女性与男性的理解 髋关节细胞生心潜能的差异和特定心腔疾病模型的保真度。

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.