Human Engineered Cardiac Tissues Created Using Induced Pluripotent Stem Cells Reveal Functional Characteristics of BRAF-Mediated Hypertrophic Cardiomyopathy.
Human Engineered Cardiac Tissues Created Using Induced Pluripotent Stem Cells Reveal Functional Characteristics of BRAF-Mediated Hypertrophic Cardiomyopathy.
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DOI：
10.1371/journal.pone.0146697
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Costa KD
中科院分区：
文献类型：
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作者：
Cashman TJ;Josowitz R;Johnson BV;Gelb BD;Costa KD
肥厚型心肌病（HCM）是心脏性猝死的主要原因，在普通人群中常常未被发现。HCM在心脏-面部-皮肤综合征（CFCS）患者中也很常见，CFCS是一种遗传性疾病，其特征是RAS/MAPK信号级联中的信号传导异常。了解此类RAS病中HCM发生的机制可能会产生新的治疗策略，但缺乏相关的人类疾病实验模型。因此，本研究的目的是开发首个肥厚型心肌病的三维人类工程化心脏组织（hECT）模型。hECT是使用从一名因BRAF激活突变导致CFCS的患者诱导多能干细胞定向分化获得的人类心肌细胞构建的。突变的心肌细胞以3:1的比例与基质细胞群直接结合，以创建成分明确的组织。与健康患者对照hECT相比，BRAF - hECT在培养第6天表现出肥厚表型，组织大小、收缩力和心房利钠肽（ANP）基因表达显著增加。收缩特性反映出BRAF - hECT的收缩和舒张速率增加，收缩持续时间缩短，在电起搏过程中其最大捕获率也显著更高，兴奋阈值更低，这与更易致心律失常的基质一致。到培养第11天，BRAF和野生型hECT之间的收缩力不再有差异，揭示了组织工程疾病建模的时间特性。主成分分析确定舒张力是从第6天到第11天变化的关键因素，第11天的BRAF - hECT具有更高的被动刚度也支持了这一点。总之，由BRAF突变细胞构建的人类工程化心脏组织首次重现了HCM表型的关键方面，为研究这种致命心脏病的内在机制和筛选新的治疗方法提供了一种新的体外模型。
Hypertrophic cardiomyopathy (HCM) is a leading cause of sudden cardiac death that often goes undetected in the general population. HCM is also prevalent in patients with cardio-facio-cutaneous syndrome (CFCS), which is a genetic disorder characterized by aberrant signaling in the RAS/MAPK signaling cascade. Understanding the mechanisms of HCM development in such RASopathies may lead to novel therapeutic strategies, but relevant experimental models of the human condition are lacking. Therefore, the objective of this study was to develop the first 3D human engineered cardiac tissue (hECT) model of HCM. The hECTs were created using human cardiomyocytes obtained by directed differentiation of induced pluripotent stem cells derived from a patient with CFCS due to an activating BRAF mutation. The mutant myocytes were directly conjugated at a 3:1 ratio with a stromal cell population to create a tissue of defined composition. Compared to healthy patient control hECTs, BRAF-hECTs displayed a hypertrophic phenotype by culture day 6, with significantly increased tissue size, twitch force, and atrial natriuretic peptide (ANP) gene expression. Twitch characteristics reflected increased contraction and relaxation rates and shorter twitch duration in BRAF-hECTs, which also had a significantly higher maximum capture rate and lower excitation threshold during electrical pacing, consistent with a more arrhythmogenic substrate. By culture day 11, twitch force was no longer different between BRAF and wild-type hECTs, revealing a temporal aspect of disease modeling with tissue engineering. Principal component analysis identified diastolic force as a key factor that changed from day 6 to day 11, supported by a higher passive stiffness in day 11 BRAF-hECTs. In summary, human engineered cardiac tissues created from BRAF mutant cells recapitulated, for the first time, key aspects of the HCM phenotype, offering a new in vitro model for studying intrinsic mechanisms and screening new therapeutic approaches for this lethal form of heart disease.