Photonics Advanced Research Center, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Anal Bioanal Chem. 2012 Jan;402(3):1073-81. doi: 10.1007/s00216-011-5554-6. Epub 2011 Nov 20.
Embryoid bodies (EBs), derived from aggregated embryonic stem (ES) cells, are capable of differentiating into all three germ layers, including the endoderm, mesoderm, and ectoderm. The initial stage of EB differentiation is the formation of a primitive endoderm (PE) layer located at the periphery of the aggregate. Raman microspectroscopy was employed to segregate PE cells from undifferentiated ES cells. The Raman spectra of the PE cells of the periphery of EBs, formed upon the withdrawal of leukemia inhibitory factor (LIF), were compared with those of the undifferentiated ES cells of the core of cell aggregates, formed in the presence of LIF. It was noticed that the PE cells have high contents of proteins and low contents of nucleic acids, lipids, and carbohydrates compared with ES cells. Also, we established the presence of another population of PE cells located in the core of the EBs. In addition, we identified some specific Raman markers to distinguish PE cells from ES cells (e.g., I(1003)/I(937)). This is the first study to investigate the PE cells of live EBs and define some Raman markers to distinguish them from undifferentiated ES cells.
胚状体（EBs）来源于聚集的胚胎干细胞（ES 细胞），能够分化为三个胚层，包括内胚层、中胚层和外胚层。EB 分化的初始阶段是在外围聚集物中形成原始内胚层（PE）层。拉曼微光谱技术被用于将 PE 细胞从未分化的 ES 细胞中分离出来。比较了在撤去白血病抑制因子（LIF）后形成的 EB 外周 PE 细胞与在存在 LIF 的情况下形成的细胞聚集体核心中未分化的 ES 细胞的拉曼光谱。结果表明，与 ES 细胞相比，PE 细胞的蛋白质含量较高，核酸、脂质和碳水化合物含量较低。此外，我们还发现了另一种位于 EB 中心的 PE 细胞群体。此外，我们还确定了一些特定的拉曼标记物来区分 PE 细胞和 ES 细胞（例如，I(1003)/I(937)）。这是首次研究活 EB 中的 PE 细胞，并定义了一些拉曼标记物来区分它们与未分化的 ES 细胞。
