Sodium Butyrate-Assisted Induction of Posterior Pre-Neural Progenitors from Pluripotent Stem Cells.

Posterior axis development during mammalian embryogenesis is driven by transient progenitor states that give rise to neural and mesodermal lineages, including neuromesodermal progenitors (NMPs). In vitro derivation of posterior progenitor populations from human pluripotent stem cells (hPSCs) has relied on modulation of Wnt and FGF signaling; however, these approaches frequently generate heterogeneous and unstable cell populations. Here, we investigated whether sodium butyrate (NaB) supplementation could promote a posteriorly biased intermediate state without extensive extracellular signaling control. We show that NaB, a histone deacetylase inhibitor, promotes the induction of posterior pre-neural progenitors (PNPs) characterized by co-expression of CDX2 and SOX2, together with suppression of SOX1. Transcriptomic analyses revealed that NaB-treated cells exhibit a posteriorly enriched PNPs with restrained anterior neural differentiation, transient early TBXT induction, and progressive activation of posterior HOX genes, consistent with an incompletely caudalized intermediate rather than a fully specified NMP population. Importantly, these PNPs remained responsive to canonical neural tube patterning cues, including retinoic acid and smoothened agonists, enabling further differentiation toward ventral spinal cord lineages. Collectively, our findings demonstrate that NaB supplementation supports posterior PNPs from hPSCs, providing a simple and reproducible platform for modeling early posterior neural development in vitro.