人诱导多能干细胞衍生的心肌细胞(hiPSC-CM)通常用于模拟心律失常性心肌病(ACM),一种以严重室性心律失常为特征的遗传性心脏病,纤维脂肪心肌替代和进行性心室功能障碍。虽然ACM是一种常染色体显性遗传疾病,不完整的外显率和可变的表现力非常普遍,导致不同的临床表现。这里,我们建议将hiPSC-CM作为一种强大的体外模型来研究ACM中的不完全外显率。从三名ACM患者的血液样品中产生了六个hiPSC系,这些患者在PKP2基因中具有外显子4的杂合缺失,两个相同突变的无症状(ASY)携带者和一个健康对照(CTR),都属于同一个家庭。在所有家族成员中进行全外显子组测序,并通过ddPCR检查hiPSC-CM,westernblot,Wes™免疫测定系统,膜片钳,免疫荧光和RNASeq。我们的结果表明ACM和ASYhiPSC-CM之间的分子和功能差异,包括更大量的突变的PKP2mRNA,连接蛋白-43蛋白的较低表达,较低的钠电流总密度,与ASYhiPSC-CM相比,ACM中更高的细胞内脂质积累和肌节解体。还发现差异表达基因,支持ACMhiPSC-CM中脂肪表型的倾向。这些数据表明hiPSC-CM是研究ACM中不完全外显率的合适模型。
Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are commonly used to model arrhythmogenic cardiomyopathy (ACM), a heritable cardiac disease characterized by severe ventricular arrhythmias, fibrofatty myocardial replacement and progressive ventricular dysfunction. Although ACM is inherited as an autosomal dominant disease, incomplete penetrance and variable expressivity are extremely common, resulting in different clinical manifestations. Here, we propose hiPSC-CMs as a powerful in vitro model to study incomplete penetrance in ACM. Six hiPSC lines were generated from blood samples of three ACM patients carrying a heterozygous deletion of exon 4 in the PKP2 gene, two asymptomatic (ASY) carriers of the same mutation and one healthy control (CTR), all belonging to the same family. Whole exome sequencing was performed in all family members and hiPSC-CMs were examined by ddPCR, western blot, Wes™ immunoassay system, patch clamp, immunofluorescence and RNASeq. Our results show molecular and functional differences between ACM and ASY hiPSC-CMs, including a higher amount of mutated PKP2 mRNA, a lower expression of the connexin-43 protein, a lower overall density of sodium current, a higher intracellular lipid accumulation and sarcomere disorganization in ACM compared to ASY hiPSC-CMs. Differentially expressed genes were also found, supporting a predisposition for a fatty phenotype in ACM hiPSC-CMs. These data indicate that hiPSC-CMs are a suitable model to study incomplete penetrance in ACM.