Project description:DAX1 (also known as Nr0b1) is regarded as an important component of the transcription factor network in mouse embryonic stem cells (ESCs). However, the role and the molecular mechanism of Dax1 in the maintenance of different pluripotency states are poorly understood. Here, we constructed a stable Dax1 knockout (KO) cell line using the CRISPR/Cas9 system to analyze the precise function of Dax1. We reported that 2i/LIF-ESCs had significantly lower Dax1 expression than LIF/serum-ESCs. Dax1KO ES cell lines could be established in 2i/LIF and their pluripotency was confirmed. In contrast, Dax1-null ESCs could not be continuously passaged in LIF/serum due to severe differentiation and apoptosis. In LIF/serum, the activities of the Core module and Myc module were significantly reduced, while the PRC2 module was activated after Dax1KO. The expression of most pro-apoptotic genes and lineage-commitment genes were drastically increased, while the down-regulated expression of anti-apoptotic genes and many pluripotency genes was observed. Our research on the pluripotent state-dependent role of Dax1 provides clues to understand the molecular regulation mechanism at different stages of early embryonic development.
Project description:Embryonic stem cell (ESC) self-renewal and differentiation is governed by a comprehensive regulatory network. Although the transcriptional regulation has been extensively investigated, post-transcriptional mechanisms controlling the ESC state are poorly understood. Here we describe a critical role of the THO complex in ESC self-renewal and differentiation. We show that THO preferentially interacts with pluripotency gene transcripts through Thoc5, and is required for self-renewal by regulating their export and expression. During differentiation, THO loses its interaction with those transcripts due to reduced Thoc5 expression, which leads to decreased expression of pluripotency proteins and facilitates differentiation. Finally, THO is also important for the establishment of pluripotency, as its depletion inhibits somatic cell reprogramming and blastocyst development. Together, our data indicates that THO regulates pluripotency gene mRNA export to control ESC self-renewal and differentiation, and uncovers a novel mechanism of post-transcriptional regulation in stem cell fate specification. RNA IP was conducted by use of antibody against Thoc2, the precipitated RNA was used to generate library using illumina Kit, and subsequently sequenced by miSeq
Project description:Elucidating the mechanism of self-renewal and pluripotency maintenance of human embryonic stem cells (hESCs) is of great significance in basic research and clinical applications. Long non-coding RNAs (lncRNAs) have been shown to play a key role in the self-renewal and pluripotency maintenance of hESCs. We previously reported that the lncRNA ESRG, which is highly expressed in undifferentiated hESCs, can interact with the replication licensing factor MCM2 and inhibit the p53 pathway to maintain the self-renewal and pluripotency of hPSCs. In addition to MCM2, RNA pull-down mass spectrometry showed that ESRG could also bind to other proteins, among which heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) attracted our attention. In this study, we show that HNRNPA1 can maintain self-renewal and pluripotency of hESCs. ESRG binds to and stabilizes HNRNPA1 protein through the ubiquitin-proteasome pathway. In addition, knockdown of ESRG or HNRNPA1 resulted in alternative splicing of TCF3, which originally and primarily encodes E12, to mainly encode E47 and inhibit CDH1 expression. HNRNPA1 could rescue the biological function changes of hESCs caused by ESRG knockdown or overexpression. Our results suggest that ESRG regulates the alternative splicing of TCF3 to affect CDH1 expression and maintain hESCs self-renewal and pluripotency by binding and stabilizing HNRNPA1 protein. This study lays a good foundation for exploring the new molecular regulatory mechanism by which ESRG maintains hESCs self-renewal and pluripotency.
Project description:Embryonic stem cell (ESC) self-renewal and differentiation is governed by a comprehensive regulatory network. Although the transcriptional regulation has been extensively investigated, post-transcriptional mechanisms controlling the ESC state are poorly understood. Here we describe a critical role of the THO complex in ESC self-renewal and differentiation. We show that THO preferentially interacts with pluripotency gene transcripts through Thoc5, and is required for self-renewal by regulating their export and expression. During differentiation, THO loses its interaction with those transcripts due to reduced Thoc5 expression, which leads to decreased expression of pluripotency proteins and facilitates differentiation. Finally, THO is also important for the establishment of pluripotency, as its depletion inhibits somatic cell reprogramming and blastocyst development. Together, our data indicates that THO regulates pluripotency gene mRNA export to control ESC self-renewal and differentiation, and uncovers a novel mechanism of post-transcriptional regulation in stem cell fate specification.
Project description:Embryonic stem cell (ESC) self-renewal and differentiation are governed by a broad-ranging regulatory network. Although the transcriptional regulatory mechanisms involved have been investigated extensively, post-transcriptional regulation is still poorly understood. Here we describe a critical role of the THO complex in ESC self-renewal and differentiation. We show that THO preferentially interacts with pluripotency gene transcripts through Thoc5, and is required for self-renewal at least in part by regulating their export and expression. During differentiation, THO loses its interaction with those transcripts due to reduced Thoc5 expression, leading to decreased expression of pluripotency proteins that facilitates exit from self-renewal. THO is also important for the establishment of pluripotency, as its depletion inhibits somatic cell reprogramming and blastocyst development. Together, our data indicate that THO regulates pluripotency gene mRNA export to control ESC self-renewal and differentiation, and therefore uncover a role for this aspect of post-transcriptional regulation in stem cell fate specification. mouse J1 cells were transfected with non-targeting (NT), Thoc2, and Thoc5 siRNAs. Total RNA was isolated 96 hours after transfection.
Project description:Long non-coding RNA ESRG was first identified in our previous study, but its physiological function, regulatory and action mechanisms in human pluripotent stem cells (hPSCs) remain largely unexplored. Here, we found that ESRG is specifically and highly expressed in hPSCs, and its transcription is directly regulated by OCT4, suggesting that ESRG may be an integral component of the core regulatory circuit regulating the pluripotent state of hPSCs. Knockdown of ESRG induces hPSC differentiation, cell cycle arrest, and apoptosis. Mechanistically, ESRG binds to minichromosome maintenance protein 2 (MCM2), a replication-licensing factor, to sustain its steady-state level and nuclear translocation, safeguarding error-free DNA replication. Further study showed that inhibition of the interaction bewteen ESRG and MCM2 results in DNA damage and activation of p53 signaling pathway, ultimately deregulates deregulates pluripotency and self-renewal of hPSCs. In sum, our observations suggest that ESRG, as a novel target of OCT4, plays an essential role in maintaining the pluripotency and self-renewal of hPSCs in collaboration with MCM2 to suppress p53 signaling. These findings provide critical insights into the mechanisms underlying the maintenance of self-renewal and pluripotency in hPSCs.
Project description:Embryonic stem cell (ESC) self-renewal and differentiation are governed by a broad-ranging regulatory network. Although the transcriptional regulatory mechanisms involved have been investigated extensively, post-transcriptional regulation is still poorly understood. Here we describe a critical role of the THO complex in ESC self-renewal and differentiation. We show that THO preferentially interacts with pluripotency gene transcripts through Thoc5, and is required for self-renewal at least in part by regulating their export and expression. During differentiation, THO loses its interaction with those transcripts due to reduced Thoc5 expression, leading to decreased expression of pluripotency proteins that facilitates exit from self-renewal. THO is also important for the establishment of pluripotency, as its depletion inhibits somatic cell reprogramming and blastocyst development. Together, our data indicate that THO regulates pluripotency gene mRNA export to control ESC self-renewal and differentiation, and therefore uncover a role for this aspect of post-transcriptional regulation in stem cell fate specification.
Project description:Human exploration of outer space will inevitably require human reproduction and development in the space environment. Embryonic stem cells (ESCs) are widely employed to study mammalian development and reproduction for their characteristics of indefinite self-renewal and pluripotency. Due to the lack of experimental opportunities and related techniques, studies of the effects of microgravity on the self-renewal and differentiation of ESCs are mostly descriptive, with in-depth mechanistic studies remaining scarce. Here we show in both mouse and human ESCs that simulated microgravity (SMG)-induced stress regulates the self-renewal and pluripotency in a conserved mechanism. Specifically, SMG upregulates the expression of heat shock protein (HSP) and/or HSF1 genes, thereby increasing the expression of core pluripotency factors and the activity of the Wnt pathway. In mESCs, the upregulation of Hsps and Hsf1 genes by SMG increased the activity of the LIF/STAT3 pathway. The upregulation of Tbx3 by increased activity of the Wnt and LIF/STAT3 pathways promotes the differentiation of both mouse and human ESCs to mesendoderm under the SMG environment. Finally, the ATAC-seq and ChIP-seq analysis in this study reveal a minor effect of SMG on the global chromatin accessibility and the overall patterns of the tested histone modifications in mESCs.
Project description:Human exploration of outer space will inevitably require human reproduction and development in the space environment. Embryonic stem cells (ESCs) are widely employed to study mammalian development and reproduction for their characteristics of indefinite self-renewal and pluripotency. Due to the lack of experimental opportunities and related techniques, studies of the effects of microgravity on the self-renewal and differentiation of ESCs are mostly descriptive, with in-depth mechanistic studies remaining scarce. Here we show in both mouse and human ESCs that simulated microgravity (SMG)-induced stress regulates the self-renewal and pluripotency in a conserved mechanism. Specifically, SMG upregulates the expression of heat shock protein (HSP) and/or HSF1 genes, thereby increasing the expression of core pluripotency factors and the activity of the Wnt pathway. In mESCs, the upregulation of Hsps and Hsf1 genes by SMG increased the activity of the LIF/STAT3 pathway. The upregulation of Tbx3 by increased activity of the Wnt and LIF/STAT3 pathways promotes the differentiation of both mouse and human ESCs to mesendoderm under the SMG environment. Finally, the ATAC-seq and ChIP-seq analysis in this study reveal a minor effect of SMG on the global chromatin accessibility and the overall patterns of the tested histone modifications in mESCs.