OCT4, SOX2 and NANOG co-regulate glycolysis and participate in somatic induced reprogramming.

OCT4, SOX2 and NANOG (OSN) are the key factors of cell reprogramming, which are involved in the maintenance of stem cell pluripotency. Recently, it has been found that glycolysis plays an important role in the process of somatic-cell-induced reprogramming; however, the synergistic effect of OSN on glycolysis has rarely been reported. In this study, chicken embryonic fibroblasts (CEF) was reprogrammed into induced pluripotent stem cells (iPSCs) by OCT4, SOX2, NANOG and LIN28 reprogramming strategy. RNA-seq showed that chicken iPSCs highly expressed pluripotent genes and the expression of the key genes of glycolysis, such as Hk1, Pfkp and Ldha, was also at a high level, while CEF was much lower. Glycolysis gene expression, glucose uptake and lactate production of CEF and iPSCs were also detected. The results showed that the glycolysis level of iPSCs was higher than that of CEF. ChIP-qPCR showed that SOX2 and NANOG transcription factors were significantly enriched in the promoter regions of Hk1, Pfkp and Ldha, while OCT4 was not. The above results indicated that OCT4, SOX2 and NANOG coordinately regulate glycolysis and participate in somatic-cell-induced reprogramming, thus setting a good foundation for further research on the molecular mechanism of somatic-cell-induced reprogramming. Supplementary Information: The online version contains supplementary material available at 10.1007/s10616-022-00530-6.

H3K4me2 Promotes the Activation of lncCPSET1 by Jun in the Chicken PGC Formation.

Primordial germ cells are the ancestors of female and male cells. Current research has shown that long non-coding RNA (lncRNA) and Histone methylation are the pivotal epigenetic factors in the PGC formation. However, there are few studies on the regulatory mechanism of lncRNA in the formation of PGC. Here, we define the lncRNA highly expressed in chicken PGC, lncCPSET1 (chicken-PGC-specifically-expressed transcript 1) This study found that compared with the interference of lncCPSET1/histone methylase Mll2 alone, the PGC formation was severely inhibited with the interference of lncCPSET1 and histone methylase Mll2 jointly in vivo and in vitro. Studies on the transcription level of lncCPSET1 found that H3K4me2 and transcription factor Jun have a positive effect on the activation of lncCPSET1; while DNA hypomethylation inhibits the expression of lncCPSET1. In terms of mechanism, compared with DNA methylation, H3K4me2 dominates lncCPSET1 activation. H3K4me2 can be enriched in the lncCPSET1 promoter, change its chromosome conformation, recruit the transcription factor Jun, and activate the expression of lncCPSET1. Taken together, we confirmed the model that H3K4me2 rather than DNA hypomethylation mediates Jun to regulate lncCPSET1 transcription, which broadens the study of lncCPSET1 pre-transcriptional mechanism.