Inhibition of KDM6 activity during murine ESC differentiation induces DNA damage
Inhibition of KDM6 activity during murine ESC differentiation induces DNA damage
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DOI：
10.1242/jcs.175174
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发表时间：
2016-02-15
影响因子：
4
通讯作者：
Becker, Matthias
中科院分区：
文献类型：
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作者：
Hofstetter, Christine;Kampka, Justyna M.;Becker, Matthias
多能胚胎干细胞(ESCs)的特点是能够无限自我更新，同时保持分化为成年生物体所有细胞类型的潜力。未分化状态和分化状态都是由特定的基因表达程序定义的，这些程序在染色质水平上受到调节。在这里，我们分析了H3K27me2和H3K27me23特异性去甲基酶KDM6A和KDM6B在小鼠胚胎干细胞分化中的作用，方法是使用针对KDM6蛋白的GSK-J4抑制剂，并通过靶向基因敲除(KO)和敲除。我们观察到，抑制H3K27去甲基酶活性会在分化的ESCs中诱导DNA损伤，同时激活DNA损伤反应(DDR)和细胞死亡，但在未分化的ESCs中不会。激光微照射实验表明，在分化ESCs的过程中，H3K27me3标记，而不是KDM6B蛋白，与γ-H_2AX阳性DNA损伤部位共存。缺乏H3K27me3减弱了GSK-J4诱导的分化Eed-KO ESCs的DDR。总之，我们的发现表明分化的ESCs依赖于KDM6，H3K27me3去甲基酶的活性在分化的ESCs的DDR和生存中起关键作用。
Pluripotent embryonic stem cells (ESCs) are characterised by their capacity to self-renew indefinitely while maintaining the potential to differentiate into all cell types of an adult organism. Both the undifferentiated and differentiated states are defined by specific gene expression programs that are regulated at the chromatin level. Here, we have analysed the contribution of the H3K27me2- and H3K27me23-specific demethylases KDM6A and KDM6B to murine ESC differentiation by employing the GSK-J4 inhibitor, which is specific for KDM6 proteins, and by targeted gene knockout (KO) and knockdown. We observe that inhibition of the H3K27 demethylase activity induces DNA damage along with activation of the DNA damage response (DDR) and cell death in differentiating but not in undifferentiated ESCs. Laser microirradiation experiments revealed that the H3K27me3 mark, but not the KDM6B protein, colocalise with gamma H2AX-positive sites of DNA damage in differentiating ESCs. Lack of H3K27me3 attenuates the GSK-J4-induced DDR in differentiating Eed-KO ESCs. Collectively, our findings indicate that differentiating ESCs depend on KDM6 and that the H3K27me3 demethylase activity is crucially involved in DDR and survival of differentiating ESCs.