Robust induction of nigro-striatal neurons from human induced pluripotent stem cells by small compound-based signal controlling

Abstract

Human induced pluripotent stem cells (hiPSCs) have an ability to generate all cell types in an organism, and hiPSC-derived somatic cells are powerful tools for drug development, toxicology and disease-modeling. The conventional protocols have been established based on the concept by recapturing the activity of morphogens working on the developmental process, however, commercially available recombinant proteins that replace with morphogens are costed and often cause problematic variations among lots. Here we reported robust neural induction protocols by the combination of small compounds that are low cost and stable materials. First, we performed dual-SMAD inhibition (inhibition of bone morphogenic protein signaling and transforming growth factor-β/activin/nodal signaling) using LDN193189 and A83-01 for efficient neural induction in chemically defined medium. And anterior-posterior patterning of the brain mediated by Wnt signaling was replaced with either XAV939 or CHIR99021. Dorsal-ventral patterning mediated by Shh signaling was replaced with purmorphamine. Based on the combination of small compounds, we generated striatal progenitors and ventral midbrain progenitors from hiPSCs, and they finally matured into striatal GABAergic neurons and midbrain dopaminergic neurons by long-term differentiation.