Laboratory of Cellular and Molecular Cardiology, Fondazione Cardiocentro Ticino and Foundation for Cardiovascular Research and Education (FCRE), 6900 Lugano, Switzerland.
Istituto di Ricerca in Biomedicina (IRB), 6500 Bellinzona, Switzerland; Faculty of Biomedical Sciences, Università della Svizzera Italiana (USI), 6900 Lugano, Switzerland.
Biochim Biophys Acta Mol Cell Res. 2020 Mar;1867(3):118538. doi: 10.1016/j.bbamcr.2019.118538. Epub 2019 Aug 28.
Induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) are a unique source of human cardiomyocytes for cardiac disease modeling. Incomplete functional maturation remains a major limitation, however. One of the determinants of iPSC-CM maturation is somatic cell origin. We therefore compared iPSC-CMs derived from different somatic cell sources.
Cardiac-derived mesenchymal progenitor cells (CPCs), bone marrow-derived mesenchymal stem cells (BMCs), and human dermal fibroblasts (HDFs) from same patients were reprogrammed into iPSCs and differentiated into iPSC-CMs. Expression of cardiac-specific genes, caffeine-responsive cells, and electrophysiological properties of differentiated cells were analyzed. To assess the contribution of epigenetic memory toward differences in gene expression observed during cardiac differentiation, DNA methylation patterns were determined in the early mesodermal cardiac promoter NKX2-5 and KCNQ1, which encodes for the pore-forming α-subunit of the slow component of delayed-rectifier potassium current (I).
Cardiac genes (MYH6, TNNI3, KCNQ1, KCNE1) were upregulated in CPC-vs. BMC- and HDF-iPSC-CMs. At early differentiation stages, CPC-iPSC-CMs displayed higher numbers of caffeine-responsive cells than BMC- and HDF-iPSC-CMs. The hERG1 (KV11.1) blocker, E4031, followed by the IKs blocker, JNJ303, increased extracellular field potential duration in CPC-iPSC-CMs to a greater extent than in BMC- and HDF-iPSC-CMs. The promoter region of NKX2-5 was more highly methylated in BMCs and HDFs compared to CPCs, and to a lesser extent in BMC-iPSCs compared to CPC-iPSCs.
These results suggest that human iPSCs from cardiac somatic cell sources may display enhanced capacity toward cardiac re-differentiation compared to non-cardiac cell sources, and that epigenetic mechanisms may play a role in this regard.
诱导多能干细胞（iPSC）衍生的心肌细胞（iPSC-CMs）是用于心脏疾病建模的人类心肌细胞的独特来源。然而，不完全的功能成熟仍然是一个主要的限制。iPSC-CM 成熟的一个决定因素是体细胞来源。因此，我们比较了来自不同体细胞来源的 iPSC-CMs。
来自同一患者的心脏衍生间充质祖细胞（CPCs）、骨髓衍生间充质干细胞（BMCs）和人真皮成纤维细胞（HDFs）被重编程为 iPSCs 并分化为 iPSC-CMs。分析分化细胞中心脏特异性基因的表达、咖啡因反应细胞和电生理特性。为了评估表观遗传记忆对心脏分化过程中观察到的基因表达差异的贡献，在早期中胚层心脏启动子 NKX2-5 和编码慢延迟整流钾电流（I）的孔形成α亚基的 KCNQ1 中确定了 DNA 甲基化模式。
CPC-vs. BMC- 和 HDF-iPSC-CMs 中心脏基因（MYH6、TNNI3、KCNQ1、KCNE1）上调。在早期分化阶段，CPC-iPSC-CMs 比 BMC-iPSC-CMs 和 HDF-iPSC-CMs 显示出更高数量的咖啡因反应细胞。hERG1（KV11.1）阻断剂 E4031 随后是 IKs 阻断剂 JNJ303，使 CPC-iPSC-CMs 的细胞外场电位持续时间增加的程度大于 BMC-iPSC-CMs 和 HDF-iPSC-CMs。与 CPC 相比，BMC 和 HDF 中的 NKX2-5 启动子区域甲基化程度更高，而与 CPC-iPSC 相比，BMC-iPSC 中的甲基化程度更低。
这些结果表明，与非心脏细胞来源相比，来自心脏体细胞来源的人类 iPSC 可能显示出增强的心脏再分化能力，并且表观遗传机制可能在这方面发挥作用。
