Project description:Conventional embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) derived from primates resemble mouse epiblast stem cells, raising an intriguing question regarding whether the naïve pluripotent state resembling mouse embryonic stem cells (mESCs) exists in primates and how to capture it in vitro. Here we identified several specific signaling modulators that are sufficient to generate rhesus monkey fibroblast-derived iPSCs with the features of naïve pluripotency in terms of growth properties, gene expression profiles, self-renewal signaling, X-reactivation and the potential to generate cross-species chimeric embryos. Interestingly, together with recent reports of naïve human pluripotent stem cells, our findings suggest several conserved signaling pathways shared with rodents and specific to primates, providing significant insights for acquiring naïve pluripotency from other mammal species. In addition, the derivation of rhesus monkey naïve iPSCs also provides a valuable cell source for use in preclinical research and disease modeling. mRNA expression analysis of 4 rhesus monkey naive iPSC lines and 2 primed iPSC lines were examed.
Project description:Pluripotency of embryonic stem cells (ESCs) can be functionally assessed according to their developmental potency. Tetraploid complementation, through which an entire organism is produced from donor pluripotent cells, is taken as the most stringent test for pluripotency. It remains unclear whether ESCs from other species besides mice can pass this test. Here we show that the rat ESCs at very early passages are also capable to produce fertile offspring by tetraploid complementation, however, this capacity is rapidly lost during culture due to the loss of genomic imprinting. Our findings support that the naïve ground state pluripotency exists in rat and can be captured in rat ESCs, yet may be subjected to species-specific regulations, which have implications for the derivation and application of naïve pluripotent stem cells in other species including human.
Project description:Pluripotency of embryonic stem cells (ESCs) can be functionally assessed according to their developmental potency. Tetraploid complementation, through which an entire organism is produced from donor pluripotent cells, is taken as the most stringent test for pluripotency. It remains unclear whether ESCs from other species besides mice can pass this test. Here we show that the rat ESCs at very early passages are also capable to produce fertile offspring by tetraploid complementation, however, this capacity is rapidly lost during culture due to the loss of genomic imprinting. Our findings support that the naïve ground state pluripotency exists in rat and can be captured in rat ESCs, yet may be subjected to species-specific regulations, which have implications for the derivation and application of naïve pluripotent stem cells in other species including human.
Project description:Derivation of naive state of mouse embryonic stem cells (mESCs) in LIF+serum (LS) culture condition is strain dependent, whereas derivation of ground state mESCs is readily possible from all strains tested so far in “2i” culture condition. ESCs can be derived from the post-implantation stage mouse embryos (EpiSCs), showing primed characteristics. In the present study, we characterized and compared the transcriptional profile of naïve, primed and ground state mESCs. Considering the importance of genetic background of mouse model for ESCs derivation in conventional culture conditions, all ESCs lines used in the study were derived from the same strain of mice. We found distinct transcriptional profiles between naive, primed and ground state mESCs. Primed state mESCs exhibit lower expression of pluripotency markers along with higher expression of lineage specific markers compared to naive and ground state mESCs. We also demonstrate that the differentiation propensity of ESCs to specific germ layer varies depending on the pluripotency state of ESCs.
Project description:During early mammalian development transient pools of pluripotent cells emerge that can be immortalised upon stem cell derivation. The pluripotent state, "naïve" or "primed", depends on the embryonic stage and derivation conditions used. Here we analyse the temporal gene expression patterns of mouse, cattle and porcine embryos at stages that harbour different types of pluripotent cells. We document conserved and divergent traits in gene expression, and identify predictor genes shared across the species that are associated with pluripotent states in vivo and in vitro Amongst these are the pluripotency-linked genes Klf4 and Lin28b The novel genes discovered include naïve- (Spic, Scpep1 and Gjb5) and primed-associated (Sema6a and Jakmip2) genes as well as naïve-to primed transition genes (Dusp6 and Trip6). Both Gjb5 and Dusp6 play a role in pluripotency since their knockdown results in differentiation and downregulation of key pluripotency genes. Together, our interspecies comparison revealed new insights of pluripotency, pluripotent stem cell identity and a new molecular criterion for distinguishing between pluripotent states in various species including human.
Project description:Defining how human pluripotent cell identity is controlled and in particular how naïve pluripotency is acquired during cell reprogramming is crucial for the future applications of pluripotent stem cells. However, the regulatory pathways of naïve cell reprogramming remain incompletely understood. Here, we used genome-wide CRISPR-Cas9 screening to identify novel regulators of primed to naïve pluripotent stem cell reprogramming, including genes that are essential for reprogramming and genes that normally impede reprogramming and whose targeted deletion led to enhanced reprogramming. Integrated analysis defined specific chromatin complexes and signalling pathways as critical regulators of naïve reprogramming, and were largely distinct from regulators of somatic cell reprogramming. Mechanistically, PRC1.3 and PRDM14 are jointly required to transcriptionally repress developmental and gene regulatory factors to ensure naïve cell reprogramming. Additionally, small molecule inhibitors of reprogramming impediments increased the efficiency of naïve cell reprogramming, and are of practical benefit that can improve on current reprogramming methods. Taken together, we have identified novel regulators controlling the establishment of naïve pluripotency in human cells, which will open up new ways to exploit the full potential of pluripotent stem cells. These results also provide new insights into mechanisms that destabilise and reconfigure cell identity during cell state transitions.