Afterload promotes maturation of human induced pluripotent stem cell derived cardiomyocytes in engineered heart tissues.
Afterload promotes maturation of human induced pluripotent stem cell derived cardiomyocytes in engineered heart tissues.
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DOI：
10.1016/j.yjmcc.2018.03.016
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发表时间：
2018-05
影响因子：
5
通讯作者：
Sniadecki NJ
中科院分区：
文献类型：
--
作者：
Leonard A;Bertero A;Powers JD;Beussman KM;Bhandari S;Regnier M;Murry CE;Sniadecki NJ
在工程心脏组织（EHT）中培养的人诱导多能干细胞衍生心肌细胞（hiPSC-CM）可用于药物筛选、疾病建模和心脏修复。然而，hiPSC-CMs的不成熟目前限制了它们的使用。由于机械负荷在发育过程中增加并促进心脏成熟，我们假设后负荷会促进eht的成熟。为了测试这一点，我们开发了一个系统，其中eht悬挂在刚性桩和柔性桩之间，其抗收缩能力可以通过施加不同长度的支撑来调节。这些支架允许我们通过将柔性柱电阻从0.09增加到9.2 μN/μm来调整两个数量级以上的后载荷条件。培养三周后，后偏转的光学跟踪显示，肌张力增强的肌理力与后负荷的程度相关，而肌理速度则随后负荷的程度而下降。因此，在中等后负荷下，EHTs的功率和功最大。等距实验表明，eht的肌力随后负荷的增加而增加，直至0.45 μN/μm，然后趋于稳定。应用后负荷增加肌节长度，心肌细胞面积和延伸，这是成熟的标志。此外，逐渐增加后负荷水平可改善钙处理，增加心脏成熟的几个关键标志物的表达，包括从胎儿到成人心室肌球蛋白重链亚型的转变。然而，在最高的后负荷条件下，病理性肥大和纤维化的标志物也上调，尽管在所有水平的后负荷测试中，大块组织刚度保持不变。总之，我们的研究结果表明，适度的后负荷可以显著改善EHTs中hiPSC-CMs的成熟，而高后负荷条件可能模仿人类心脏病理的某些方面，导致机械负荷升高。
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) grown in engineered heart tissue (EHT) can be used for drug screening, disease modeling, and heart repair. However, the immaturity of hiPSC-CMs currently limits their use. Because mechanical loading increases during development and facilitates cardiac maturation, we hypothesized that afterload would promote maturation of EHTs. To test this we developed a system in which EHTs are suspended between a rigid post and a flexible one, whose resistance to contraction can be modulated by applying braces of varying length. These braces allow us to adjust afterload conditions over two orders of magnitude by increasing the flexible post resistance from 0.09 up to 9.2 μN/μm. After three weeks in culture, optical tracking of post deflections revealed that auxotonic twitch forces increased in correlation with the degree of afterload, whereas twitch velocities decreased with afterload. Consequently, the power and work of the EHTs were maximal under intermediate afterloads. When studied isometrically, the inotropy of EHTs increased with afterload up to an intermediate resistance (0.45 μN/μm) and then plateaued. Applied afterload increased sarcomere length, cardiomyocyte area and elongation, which are hallmarks of maturation. Furthermore, progressively increasing the level of afterload led to improved calcium handling, increased expression of several key markers of cardiac maturation, including a shift from fetal to adult ventricular myosin heavy chain isoforms. However, at the highest afterload condition, markers of pathological hypertrophy and fibrosis were also upregulated, although the bulk tissue stiffness remained the same for all levels of applied afterload tested. Together, our results indicate that application of moderate afterloads can substantially improve the maturation of hiPSC-CMs in EHTs, while high afterload conditions may mimic certain aspects of human cardiac pathology resulting from elevated mechanical overload.
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影响因子：
3.4
作者：
BEYAR, R;SIDEMAN, S
通讯作者：
SIDEMAN, S
影响因子：
2.4
作者：
Jacot JG;Martin JC;Hunt DL
通讯作者：
Hunt DL
影响因子：
9.5
作者：
Hirt MN;Sörensen NA;Bartholdt LM;Boeddinghaus J;Schaaf S;Eder A;Vollert I;Stöhr A;Schulze T;Witten A;Stoll M;Hansen A;Eschenhagen T
通讯作者：
Eschenhagen T
影响因子：
16.1
作者：
Feric NT;Radisic M
通讯作者：
Radisic M
影响因子：
3
作者：
Bielawski, Kevin S.;Leonard, Andrea;Sniadecki, Nathan J.
通讯作者：
Sniadecki, Nathan J.