Li Xinyue, Ji Guangyu, Zhou Juan, Du Jingyi, Li Xian, Shi Wei, Hu Yong, Zhou Wenjuan, Hao Aijun
Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Mental Disorders, Department of Anatomy and Histoembryology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China.
Department of Foot and Ankle Surgery, Cheeloo College of Medicine, The Second Hospital, Shandong University, Jinan, China.
Front Cell Dev Biol. 2021 Jan 26;8:581636. doi: 10.3389/fcell.2020.581636. eCollection 2020.
The neural induction constitutes the initial step in the generation of the neural tube. Pcgf1, as one of six Pcgf paralogs, is a maternally expressed gene, but its role and mechanism in early neural induction during neural tube development have not yet been explored. In this study, we found that zebrafish embryos exhibited a small head and reduced or even absence of telencephalon after inhibiting the expression of Pcgf1. Moreover, the neural induction process of zebrafish embryos was abnormally activated, and the subsequent NSC self-renewal was inhibited after injecting the Pcgf1 MO. The results of also showed that knockdown of Pcgf1 increased the expression levels of the neural markers Pax6, Pou3f1, and Zfp521, but decreased the expression levels of the pluripotent markers Oct4, Hes1, and Nanog, which further confirmed that Pcgf1 was indispensable for maintaining the pluripotency of P19 cells. To gain a better understanding of the role of Pcgf1 in early development, we analyzed mRNA profiles from Pcgf1-deficient P19 cells using RNA-seq. We found that the differentially expressed genes were enriched in many functional categories, which related to the development phenotype, and knockdown of Pcgf1 increased the expression of histone demethylases. Finally, our results showed that Pcgf1 loss-of-function decreased the levels of transcriptional repression mark H3K27me3 at the promoters of Ngn1 and Otx2, and the levels of transcriptional activation mark H3K4me3 at the promoters of Pou5f3 and Nanog. Together, our findings reveal that Pcgf1 might function as both a facilitator for pluripotent maintenance and a repressor for neural induction.
神经诱导是神经管形成的起始步骤。Pcgf1作为六种Pcgf旁系同源物之一，是一种母源表达基因，但其在神经管发育早期神经诱导中的作用和机制尚未得到探索。在本研究中，我们发现抑制Pcgf1的表达后，斑马鱼胚胎出现小头，端脑缩小甚至缺失。此外，注射Pcgf1吗啉代寡核苷酸后，斑马鱼胚胎的神经诱导过程被异常激活，随后神经干细胞的自我更新受到抑制。研究结果还表明，敲低Pcgf1可增加神经标志物Pax6、Pou3f1和Zfp521的表达水平，但降低多能性标志物Oct4、Hes1和Nanog的表达水平，这进一步证实Pcgf1对于维持P19细胞的多能性不可或缺。为了更好地了解Pcgf1在早期发育中的作用，我们使用RNA测序分析了Pcgf1缺陷型P19细胞的mRNA谱。我们发现差异表达基因富集在许多与发育表型相关的功能类别中，并且敲低Pcgf会增加组蛋白去甲基化酶的表达。最后，我们的结果表明，Pcgf1功能丧失会降低Ngn1和Otx2启动子处转录抑制标记H3K27me3的水平，以及Pou5f3和Nanog启动子处转录激活标记H3K4me3的水平。总之，我们的研究结果表明，Pcgf1可能既是多能性维持的促进因子，也是神经诱导的抑制因子。
