Moore Jennifer C, Fu Jidong, Chan Yau-Chi, Lin Dawei, Tran Ha, Tse Hung-Fat, Li Ronald A
Stem Cell Program, University of California, Room 650, Shriners Hospital, 2425 Stockton Blvd, Davis, CA 95817, USA.
Biochem Biophys Res Commun. 2008 Aug 8;372(4):553-8. doi: 10.1016/j.bbrc.2008.05.076. Epub 2008 May 27.
Although both the H1 and HES2 human embryonic stem cell lines (NIH codes: WA01 and ES02, respectively) are capable of forming all three germ layers and their derivatives, various lines of evidence including the need to use different protocols to induce cardiac differentiation hint that they have distinct preferences to become chamber-specific heart cells. However, a direct systematic comparison has not been reported. Here we electrophysiologically demonstrated that the distributions of ventricular-, atrial- and pacemaker-like derivatives were indeed different (ratios=39:61:0 and 64:33:3 for H1 and HES2, respectively). Based on these results, we hypothesized the differences in their cardiogenic potentials are imprinted in the proteomes of undifferentiated H1 and HES2. Using multiplexing, high-resolution 2-D Differential In Gel Electrophoresis (DIGE) to minimize gel-to-gel variations that are common in conventional 2-D gels, a total of 2000 individual protein spots were separated. Of which, 55 were >2-fold differentially expressed in H1 and HES2 (p<0.05) and identified by mass spectrometery. Bioinformatic analysis of these protein differences further revealed candidate pathways that contribute to the H1 and HES2 phenotypes. We conclude that H1 and HES2 have predetermined preferences to become ventricular, atrial, and pacemaker cells due to discrete differences in their proteomes. These results improve our basic understanding of hESCs and may lead to mechanism-based methods for their directed cardiac differentiation into chamber-specific cardiomyocytes.
尽管H1和HES2这两个人类胚胎干细胞系（美国国立卫生研究院代码分别为WA01和ES02）都能够形成所有三个胚层及其衍生物，但包括需要使用不同方案来诱导心脏分化在内的各种证据表明，它们在分化为特定腔室的心脏细胞方面有不同的偏好。然而，尚未有直接的系统比较报道。在这里，我们通过电生理学证明，心室样、心房样和起搏样衍生物的分布确实不同（H1和HES2的比例分别为39:61:0和64:33:3）。基于这些结果，我们推测它们在心脏发生潜能上的差异在未分化的H1和HES2蛋白质组中就已存在。使用多路复用、高分辨率的二维差异凝胶电泳（DIGE）来最小化传统二维凝胶中常见的凝胶间差异，共分离出2000个单个蛋白质斑点。其中，有55个在H1和HES2中差异表达超过2倍（p<0.05），并通过质谱鉴定。对这些蛋白质差异的生物信息学分析进一步揭示了导致H1和HES2表型的候选途径。我们得出结论，由于H1和HES2蛋白质组存在离散差异，它们在分化为心室、心房和起搏细胞方面具有预先确定的偏好。这些结果增进了我们对人类胚胎干细胞的基本理解，并可能导致基于机制的方法，将其定向分化为特定腔室的心肌细胞。
