An interplay between extracellular signalling and the dynamics of the exit from pluripotency drives cell fate decisions in mouse ES cells

Abstract

Embryonic Stem cells derived from the epiblast tissue of the mammalian blastocyst retain the capability to differentiate into any adult cell type and are able to self-renew indefinitely under appropriate culture conditions. Despite the large amount of knowledge that we have accumulated to date about the regulation and control of self-renewal, efficient directed differentiation into specific tissues remains elusive. In this work, we have analysed in a systematic manner the interaction between the dynamics of loss of pluripotency and Activin/Nodal, BMP4 and Wnt signalling in fate assignment during the early stages of differentiation of mouse ES cells in culture. During the initial period of differentiation, cells exit from pluripotency and enter an Epi-like state. Following this transient stage, and under the influence of Activin/Nodal and BMP signalling, cells face a fate choice between differentiating into neuroectoderm and contributing to Primitive Streak fates. We find that Wnt signalling does not suppress neural development as previously thought and that it aids both fates in a context dependent manner. Our results suggest that as cells exit pluripotency they are endowed with a primary neuroectodermal fate and that the potency to become endomesodermal rises with time. We suggest that this situation translates into a “race for fates” in which the neuroectodermal fate has an advantage.

Negative feedback via RSK modulates Erk‐dependent progression from naïve pluripotency

“…Cells were plated in ActivinA and CH after 25 h of N2B27 + BI treatment to initiate primitive streak‐like differentiation 71, 72, 73, 74. On day 3, BI‐treated cells upregulated Brachyury similar to untreated controls (Fig 5I).…”

NOTCH activation interferes with cell fate specification in the gastrulating mouse embryo

“…The identification of the regulatory networks controlling these sequential events has recently benefited from studies highlighting the similarities between the precursors present in the embryo and the in vitro cell types obtained in neural differentiation protocols of stem cells (IwafuchiDoi et al, 2012;Lupo et al, 2014). In vivo and in vitro evidence has demonstrated that inhibition of NODAL/ACTIVIN signalling promotes neural fate acquisition in the mouse embryo, as well as during differentiation of mESCs, mouse epiblast stem cells (mEpiSC), and hESCs (Camus et al, 2006;Chng et al, 2010;Li et al, 2013;Patani et al, 2009;Smith et al, 2008;Turner et al, 2014;Vallier et al, 2009;Watanabe et al, 2005). It is tempting to extrapolate that the attenuation of NODAL signalling observed in N1ICD epi embryos from E6.5 contributes to the premature expression of Sox1 in the distal anterior epiblast of these embryos.…”

Generation of Aggregates of Mouse Embryonic Stem Cells that Show Symmetry Breaking, Polarization and Emergent Collective Behaviour <em>In Vitro</em>

“…3. Aspirate the final glycerol:PBT solution and replace with 1 ml mounting medium 24 . The protocol may be paused at this point prior to mounting (if paused, seal the wells with paraffin film and store the staining wells at 4 °C).…”