BIN1 Induces the Formation of T-Tubules and Adult-Like Ca2+ Release Units in Developing Cardiomyocytes
BIN1 Induces the Formation of T-Tubules and Adult-Like Ca2+ Release Units in Developing Cardiomyocytes
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DOI：
10.1002/stem.2927
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发表时间：
2019-01-01
期刊：
影响因子：
5.2
通讯作者：
Santana, Luis Fernando
中科院分区：
文献类型：
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作者：
De La Mata, Ana;Tajada, Sendoa;Santana, Luis Fernando
人胚胎干细胞衍生的心肌细胞（hESC-CM）是心脏病新的细胞疗法的中心，但也可以作为心脏细胞发育的体外模型。hESC-CM的一个有趣的特征是，尽管它们表达收缩蛋白并具有肌节，但它们不发育具有成人样Ca 2+释放单位（CRU）的横小管（T-小管）。我们测试了以下假设：hESC-CM中蛋白质BIN 1的表达促进T-小管形成，促进Ca（V）1.2通道沿小管沿着聚集，并导致稳定CRU的发育。使用电生理学、[Ca 2 +]（i）成像和超分辨率显微镜，我们发现BIN 1表达诱导hESC-CM中的T-小管发育，同时增加向更心室样表型的分化。电压门控性Ca（V）1.2通道沿着分布于hESC-CM的肌膜和T小管。随着BIN 1表达增加和细胞成熟，T小管的长度和宽度以及Ca（V）1.2簇的表达和大小增加。BIN 1表达增加Ca（V）1.2通道活性和通道簇内偶联门控的可能性。有趣的是，BIN 1簇也作为肌浆网（SR）锚定和稳定的网站。因此，表达BIN 1的细胞比对照细胞具有更多的Ca（V）1.2-ryanodine受体连接。这与兴奋-收缩偶联期间较大的[Ca 2 +]（i）瞬变有关。我们的数据支持BIN 1是T-小管形成和Ca（V）1.2通道传递的关键调节剂的观点。通过研究BIN 1在hESC-CM分化过程中的作用，我们发现BIN 1对Ca（V）1.2通道聚集、连接性SR组织和兴奋-收缩偶联的建立也很重要。干细胞2019;37：54-64
Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) are at the center of new cell-based therapies for cardiac disease, but may also serve as a useful in vitro model for cardiac cell development. An intriguing feature of hESC-CMs is that although they express contractile proteins and have sarcomeres, they do not develop transverse-tubules (T-tubules) with adult-like Ca2+ release units (CRUs). We tested the hypothesis that expression of the protein BIN1 in hESC-CMs promotes T-tubules formation, facilitates Ca(V)1.2 channel clustering along the tubules, and results in the development of stable CRUs. Using electrophysiology, [Ca2+](i) imaging, and super resolution microscopy, we found that BIN1 expression induced T-tubule development in hESC-CMs, while increasing differentiation toward a more ventricular-like phenotype. Voltage-gated Ca(V)1.2 channels clustered along the surface sarcolemma and T-tubules of hESC-CM. The length and width of the T-tubules as well as the expression and size of Ca(V)1.2 clusters grew, as BIN1 expression increased and cells matured. BIN1 expression increased Ca(V)1.2 channel activity and the probability of coupled gating within channel clusters. Interestingly, BIN1 clusters also served as sites for sarcoplasmic reticulum (SR) anchoring and stabilization. Accordingly, BIN1-expressing cells had more Ca(V)1.2-ryanodine receptor junctions than control cells. This was associated with larger [Ca2+](i) transients during excitation-contraction coupling. Our data support the view that BIN1 is a key regulator of T-tubule formation and Ca(V)1.2 channel delivery. By studying the role of BIN1 during the differentiation of hESC-CMs, we show that BIN1 is also important for Ca(V)1.2 channel clustering, junctional SR organization, and the establishment of excitation-contraction coupling. Stem Cells 2019;37:54-64