Lin28a is a pluripotent factor that promotes somatic cell reprogramming. Unlike other pluripotent factors, Lin28a expression is transient and accumulated in primed embryonic stem (ES) cells, but its exact function and...Lin28a is a pluripotent factor that promotes somatic cell reprogramming. Unlike other pluripotent factors, Lin28a expression is transient and accumulated in primed embryonic stem (ES) cells, but its exact function and mechanism in the conversion of ES cells from naive to primed state remain unclear. Here, we present evidence for Dppa3, a protein originally known for its role in germ cell development, as a downstream target of Lin28a in naive–primed conversion. Using rescue experiment, we demonstrate that Dppa3 functions predominantly downstream of Lin28a during naive–primed state conversion. Higher level of Lin28a prevents let-7 maturation and results in Dnmt3a/b (target of let-7) upregulation, which in turn induces hypermethylation of the Dppa3 promoter. Dppa3 demarcates naive versus primed pluripotency states. These results emphasize that Lin28a plays an important role during the naive–primed state conversion of ES cells, which is partially mediated by a Lin28a–let-7–Dnmt3a/b–Dppa3 axis.展开更多
文摘多能发育相关因子2和4(developmental pluripotency-associated 2 and 4,DPPA2/DPPA4)是激活类2细胞期胚胎干细胞(2-cell-like embryonic stem cells,2CL ESCs)基因组的重要调控因子,同时调控胚胎干细胞的增殖。DPPA2/DPPA4在牛早期胚胎发育过程中的功能和机制尚不清楚。本研究利用RNA干扰技术结合胚胎显微注射技术敲低牛胚胎中的DPPA2/DPPA4后发现,与阴性对照组相比,敲低组中牛胚胎的8—16细胞阶段卵裂率和囊胚阶段囊胚率无显著差异,但是囊胚总细胞数、滋养层细胞数和内细胞团细胞数均显著减少(P<0.001、P<0.05、P<0.01)。进一步通过RNA测序(RNA-sequencing,RNA-Seq)分析发现,与阴性对照组相比,敲低组的晚期桑葚胚中,NOTCH信号通路的核心转录因子RBPJ(recombination signal binding protein gene for immunoglobulin kappa J region)的表达量显著下调(P<0.05),而本课题组前期实验证明,RBPJ敲低会导致牛早期胚胎的囊胚质量严重受损。本研究结果揭示了DPPA2/DPPA4在牛着床前胚胎发育中可能通过调节RBPJ的表达来影响细胞增殖。
基金the National Natural Science Foundation of China (31771636, 81671734, and 81501528)National Key R&D Plan (2017YFA0103201 and 2011DAV00088)+2 种基金Tianjin Natural Science Foundation (18JCYBJC24400)CAMS Initiative for Innovative Medicine (CAMS-12M 2016-12M-1-017)Program for Changjiang Scholars and Innovative Research Team in University (IRT13023).
文摘Lin28a is a pluripotent factor that promotes somatic cell reprogramming. Unlike other pluripotent factors, Lin28a expression is transient and accumulated in primed embryonic stem (ES) cells, but its exact function and mechanism in the conversion of ES cells from naive to primed state remain unclear. Here, we present evidence for Dppa3, a protein originally known for its role in germ cell development, as a downstream target of Lin28a in naive–primed conversion. Using rescue experiment, we demonstrate that Dppa3 functions predominantly downstream of Lin28a during naive–primed state conversion. Higher level of Lin28a prevents let-7 maturation and results in Dnmt3a/b (target of let-7) upregulation, which in turn induces hypermethylation of the Dppa3 promoter. Dppa3 demarcates naive versus primed pluripotency states. These results emphasize that Lin28a plays an important role during the naive–primed state conversion of ES cells, which is partially mediated by a Lin28a–let-7–Dnmt3a/b–Dppa3 axis.
