Poon Ellen, Keung Wendy, Liang Yimin, Ramalingam Rajkumar, Yan Bin, Zhang Shaohong, Chopra Anant, Moore Jennifer, Herren Anthony, Lieu Deborah K, Wong Hau San, Weng Zhihui, Wong On Tik, Lam Yun Wah, Tomaselli Gordon F, Chen Christopher, Boheler Kenneth R, Li Ronald A
From the Stem Cell and Regenerative Medicine Consortium (E.P., W.K., B.Y., Z.W., O.T. W., K.R.B., R.A.L.) and Department of Physiology, LKS Faculty of Medicine (E.P., W.K., B.Y., Z.W., O.T.W., K.R.B., R.A.L.), University of Hong Kong, Hong Kong, P.R. China; Departments of Biology and Chemistry (Y.M.L., R.R., Y.W.L.) and Computer Science (H.S.W.), City University of Hong Kong, Hong Kong, P.R. China; Department of Computer Science, Guangzhou University, Guangzhou, P.R. China (S.Z.); Department of Bioengineering, Boston University, MA (A.C., C.C.); Harvard Wyss Institute for Biologically Inspired Engineering, Boston, MA (A.C., C.C.); Department of Cell Biology and Human Anatomy, University of California, Davis (J.M., A.H., D.K.L.); Cardiovascular Research Center, Mount Sinai School of Medicine, New York (D.K.L., R.A.L.); and Division of Cardiology, Johns Hopkins University, Baltimore, MD (G.F.T., K.R.B.).
Circ Cardiovasc Genet. 2015 Jun;8(3):427-36. doi: 10.1161/CIRCGENETICS.114.000918. Epub 2015 Mar 10.
Differentiation of pluripotent human embryonic stem cells (hESCs) to the cardiac lineage represents a potentially unlimited source of ventricular cardiomyocytes (VCMs), but hESC-VCMs are developmentally immature. Previous attempts to profile hESC-VCMs primarily relied on transcriptomic approaches, but the global proteome has not been examined. Furthermore, most hESC-CM studies focus on pathways important for cardiac differentiation, rather than regulatory mechanisms for CM maturation. We hypothesized that gene products and pathways crucial for maturation can be identified by comparing the proteomes of hESCs, hESC-derived VCMs, human fetal and human adult ventricular and atrial CMs.
Using two-dimensional-differential-in-gel electrophoresis, 121 differentially expressed (>1.5-fold; P<0.05) proteins were detected. The data set implicated a role of the peroxisome proliferator-activated receptor α signaling in cardiac maturation. Consistently, WY-14643, a peroxisome proliferator-activated receptor α agonist, increased fatty oxidative enzyme level, hyperpolarized mitochondrial membrane potential and induced a more organized morphology. Along this line, treatment with the thyroid hormone triiodothyronine increased the dynamic tension developed in engineered human ventricular cardiac microtissue by 3-fold, signifying their maturation.
We conclude that the peroxisome proliferator-activated receptor α and thyroid hormone pathways modulate the metabolism and maturation of hESC-VCMs and their engineered tissue constructs. These results may lead to mechanism-based methods for deriving mature chamber-specific CMs.
多能性人类胚胎干细胞（hESCs）向心脏谱系的分化代表了心室心肌细胞（VCMs）潜在的无限来源，但hESC-VCMs在发育上不成熟。以往对hESC-VCMs进行特征分析的尝试主要依赖于转录组学方法，而尚未对整体蛋白质组进行研究。此外，大多数hESC-CM研究聚焦于对心脏分化重要的信号通路，而非心肌细胞成熟的调控机制。我们推测，通过比较hESCs、hESC来源的VCMs、人类胎儿以及人类成年心室和心房心肌细胞的蛋白质组，可以鉴定出对成熟至关重要的基因产物和信号通路。
使用二维差异凝胶电泳，检测到121种差异表达（>1.5倍；P<0.05）的蛋白质。该数据集表明过氧化物酶体增殖物激活受体α信号在心脏成熟中发挥作用。同样，过氧化物酶体增殖物激活受体α激动剂WY-14643增加了脂肪酸氧化酶水平，使线粒体膜电位超极化，并诱导出更有序的形态。据此，用甲状腺激素三碘甲状腺原氨酸处理使工程化人类心室心脏微组织中产生的动态张力增加了3倍，表明它们成熟了。
我们得出结论，过氧化物酶体增殖物激活受体α和甲状腺激素信号通路调节hESC-VCMs及其工程化组织构建体的代谢和成熟。这些结果可能会带来基于机制的方法来获得成熟的腔室特异性心肌细胞。
