Lipid rafts increase to facilitate ectoderm lineage specification of differentiating embryonic stem cells

Lipid rafts are packed nanoscopic domains on plasma membrane responsible for transducing extracellular stimuli into cellular signalling. In response to environmental cues, pluripotent cells exit from pluripotency and undergo commitment to specific lineages. Depletion of raft component glycoshpingolipid causes ectodermal layer abnormality and mouse embryonic lethality. But it remains unclear whether rafts play a role in lineage specification in vivo or in vitro. Here, treating mouse embryonic stem cells (mESCs) with retinoic acid (RA), we observed that lipid rafts increased since early stage, especially in the induced ectoderm-like cells. Stochastic optical reconstruction microscopy characterized at super-resolution the distinct raft features in mESCs and RA-induced ectoderm-like cells. Raft disruption via ugcg knockout or early stage raft inhibition significantly diminished RA-induced commitment of ectoderm-like cells. Meanwhile, raft inhibition delayed pluripotency exit during RA induction. Therefore, lipid rafts increase to facilitate specification of ectoderm-like cells as well as pluripotency exit of differentiating mESCs.