Division of Regenerative Medicine and Therapeutics, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science, 86 Nishimachi, Yonago, Tottori 683-8503, Japan.
Biochem Biophys Res Commun. 2013 Feb 8;431(2):225-31. doi: 10.1016/j.bbrc.2012.12.128. Epub 2013 Jan 9.
P19 embryonal carcinoma (EC) cells are pluripotent stem cells and have numerous morphological and biochemical properties in common with embryonic stem (ES) cells. However, P19 cells differentiate very ineffectively as embryoid bodies (EBs) without the specific chemical inducers whereas ES cells exhibit spontaneous differentiation to the three germ layers. Recently the heterochromatin protein 1 (HP1) family protein HP1γ, which is an epigenetic modulator that binds histone H3 methylated at lysine 9, is shown to be associated with the progression from pluripotent to differentiated status in ES cells. Therefore, to study the role of HP1γ in the differentiation capacity of P19 cells, we have established a HP1γ-overexpressing P19 cell line (HPlγ-P19). Similar to the parental P19 cells, undifferentiated HP1γ-P19 cells continued to express pluripotency marker genes. However, HP1γ-P19 cells exhibited significant morphological differentiation including beating cardiomyocytes, as well as Tuj1-positive neuronal cells and Sox17-positive endodermal cells after EB formation under a normal culture condition. Moreover, real-time RT-qPCR analysis revealed that HP1γ-P19 EB cells expressed various differentiation marker genes. Thus, HP1γ-P19 cells could give rise to all three germ layers in EBs without any drug treatment. Therefore, HP1γ affects the spontaneous differentiation potential of P19 cells, and might play major roles in the decision of cell fates in pluripotent stem cells.
P19 胚胎癌细胞 (EC) 是多能干细胞，具有许多与胚胎干细胞 (ES) 共同的形态和生化特性。然而，P19 细胞在没有特定化学诱导剂的情况下作为胚状体 (EBs) 非常低效地分化，而 ES 细胞则自发分化为三个胚层。最近，异染色质蛋白 1 (HP1) 家族蛋白 HP1γ 被证明与 ES 细胞从多能状态向分化状态的进展有关，它是一种表观遗传调节剂，与组蛋白 H3 赖氨酸 9 甲基化结合。因此，为了研究 HP1γ 在 P19 细胞分化能力中的作用，我们建立了 HP1γ 过表达 P19 细胞系 (HPlγ-P19)。与亲本 P19 细胞相似，未分化的 HP1γ-P19 细胞继续表达多能性标记基因。然而，在正常培养条件下形成 EB 后，HP1γ-P19 细胞表现出明显的形态分化，包括搏动的心肌细胞，以及 Tuj1 阳性神经元细胞和 Sox17 阳性内胚层细胞。此外，实时 RT-qPCR 分析显示，HP1γ-P19 EB 细胞表达各种分化标记基因。因此，HP1γ-P19 细胞在没有任何药物处理的情况下可以在 EBs 中产生所有三个胚层。因此，HP1γ 影响 P19 细胞的自发分化潜能，并可能在多能干细胞中细胞命运的决定中发挥重要作用。
