The embryo instructs the allocation of cell states to spatially regulate functions. In the blastocyst, patterning of trophoblast (TR) cells ensures successful implantation and placental development... Show moreThe embryo instructs the allocation of cell states to spatially regulate functions. In the blastocyst, patterning of trophoblast (TR) cells ensures successful implantation and placental development. Here, we defined an optimal set of molecules secreted by the epiblast (inducers) that captures in vitro stable, highly self-renewing mouse trophectoderm stem cells (TESCs) resembling the blastocyst stage. When exposed to suboptimal inducers, these stem cells fluctuate to form interconvertible subpopulations with reduced self-renewal and facilitated dif-ferentiation, resembling peri-implantation cells, known as TR stem cells (TSCs). TESCs have enhanced capacity to form blastoids that implant more efficientlyin utero due to inducers maintaining not only local TR proliferation and self-renewal, but also WNT6/7B secretion that stimulates uterine decidualization. Overall, the epiblast main-tains sustained growth and decidualization potential of abutting TR cells, while, as known, distancing imposed by the blastocyst cavity differentiates TR cells for uterus adhesion, thus patterning the essential functions of implantation. Show less
Neagu, A.; Genderen, E. vanl; Escudero, I.; Verwegen, L.; Kurek, D.; Lehmann, J.; ... ; Berge, D. ten 2020
Neagu, van Genderen and Escudero et al. show that simultaneous inhibition of WNT and MEK signalling maintains a naive-primed intermediate pluripotency state in vitro, which displays features of the... Show moreNeagu, van Genderen and Escudero et al. show that simultaneous inhibition of WNT and MEK signalling maintains a naive-primed intermediate pluripotency state in vitro, which displays features of the mouse embryonic rosette.Following implantation, the naive pluripotent epiblast of the mouse blastocyst generates a rosette, undergoes lumenogenesis and forms the primed pluripotent egg cylinder, which is able to generate the embryonic tissues. How pluripotency progression and morphogenesis are linked and whether intermediate pluripotent states exist remain controversial. We identify here a rosette pluripotent state defined by the co-expression of naive factors with the transcription factor OTX2. Downregulation of blastocyst WNT signals drives the transition into rosette pluripotency by inducing OTX2. The rosette then activates MEK signals that induce lumenogenesis and drive progression to primed pluripotency. Consequently, combined WNT and MEK inhibition supports rosette-like stem cells, a self-renewing naive-primed intermediate. Rosette-like stem cells erase constitutive heterochromatin marks and display a primed chromatin landscape, with bivalently marked primed pluripotency genes. Nonetheless, WNT induces reversion to naive pluripotency. The rosette is therefore a reversible pluripotent intermediate whereby control over both pluripotency progression and morphogenesis pivots from WNT to MEK signals. Show less
Neagu, A.; Genderen, E. van; Escudero, I.; Verwegen, L.; Kurek, D.; Lehmann, J.; ... ; Berge, D. ten 2020
Following implantation, the naive pluripotent epiblast of the mouse blastocyst generates a rosette, undergoes lumenogenesis and forms the primed pluripotent egg cylinder, which is able to generate... Show moreFollowing implantation, the naive pluripotent epiblast of the mouse blastocyst generates a rosette, undergoes lumenogenesis and forms the primed pluripotent egg cylinder, which is able to generate the embryonic tissues. How pluripotency progression and morphogenesis are linked and whether intermediate pluripotent states exist remain controversial. We identify here a rosette pluripotent state defined by the co-expression of naive factors with the transcription factor OTX2. Downregulation of blastocyst WNT signals drives the transition into rosette pluripotency by inducing OTX2. The rosette then activates MEK signals that induce lumenogenesis and drive progression to primed pluripotency. Consequently, combined WNT and MEK inhibition supports rosette-like stem cells, a self-renewing naive-primed intermediate. Rosette-like stem cells erase constitutive heterochromatin marks and display a primed chromatin landscape, with bivalently marked primed pluripotency genes. Nonetheless, WNT induces reversion to naive pluripotency. The rosette is therefore a reversible pluripotent intermediate whereby control over both pluripotency progression and morphogenesis pivots from WNT to MEK signals. Neagu, van Genderen and Escudero et al. show that simultaneous inhibition of WNT and MEK signalling maintains a naive-primed intermediate pluripotency state in vitro, which displays features of the mouse embryonic rosette. Show less
Tuysuz, N.; Bloois, L. van; Brink, S. van den; Begthel, H.; Verstegen, M.M.A.; Cruz, L.J.; ... ; Berge, D. ten 2017
Therapeutic application of human embryonic stem cells (hESCs) requires precise control over their differentiation. However, spontaneous differentiation is prevalent, and growth factors induce... Show moreTherapeutic application of human embryonic stem cells (hESCs) requires precise control over their differentiation. However, spontaneous differentiation is prevalent, and growth factors induce multiple cell types; e. g., the mesoderm inducer BMP4 generates both mesoderm and trophoblast. Here we identify endogenous WNT signals as BMP targets that are required and sufficient for mesoderm induction, while trophoblast induction is WNT independent, enabling the exclusive differentiation toward either lineage. Furthermore, endogenous WNT signals induce loss of pluripotency in hESCs and their murine counterparts, epiblast stem cells (EpiSCs). WNT inhibition obviates the need to manually remove differentiated cells to maintain cultures and improves the efficiency of directed differentiation. In EpiSCs, WNT inhibition stabilizes a pregastrula epiblast state with novel characteristics, including the ability to contribute to blastocyst chimeras. Our findings show that endogenous WNT signals function as hidden mediators of growth factor-induced differentiation and play critical roles in the self-renewal of hESCs and EpiSCs. Show less
Loosdregt, J. van; Fleskens, V.; Tiemessen, M.M.; Mokry, M.; Boxtel, R. van; Meerding, J.; ... ; Coffer, P.J. 2013
