A STAT3-regulated lncRNA integrates microRNA biogenesis and sequestration to safeguard naive pluripotency

Leukemia inhibitory factor (LIF)/STAT3 signaling is central to maintaining naive pluripotency in mouse embryonic stem cells (mESCs). We identify Asgard, a previously uncharacterized long non-coding RNA, as a direct STAT3 target required for efficient self-renewal. Asgard is rapidly induced by LIF, enriched in the epiblast, and its depletion reduces alkaline phosphatase-positive colony formation while enhancing differentiation. Mechanistically, Asgard fulfils a dual role: it acts as the primary transcript for the differentiation-promoting microRNA Odin, while also functioning as a sponge to sequester Odin and related miRNAs. This dual mechanism enables Asgard to both generate and buffer pro-differentiation signals, thereby stabilizing the pluripotent state while preserving responsiveness to lineage cues. Our work reveals a new paradigm in RNA-mediated control of stem cell identity, where a single STAT3-regulated lncRNA couples microRNA production with competitive inhibition to safeguard naive pluripotency.