Derivation and Identification of Motor Neurons from Human Urine-Derived Induced Pluripotent Stem Cells

Figure 1

(a) Time course and small-molecule cocktail for the differentiation of iPSCs into mature MNs. Following exposure to CHIR99021, SB431542, and DMH1 for 6 days, the iPSCs differentiated into NEPs. Over 6 days, with the addition of RA and Pur, the cells differentiated into MNPs. During the last 2 weeks of differentiation, in the presence of RA, Pur, and neurotrophic factors, the MNPs finally differentiated into mature MNs. (b) Morphology of the cells derived from the three iPSC lines at every differentiation stage. Before the differentiation process, the three iPSC lines exhibited uniform, undifferentiated morphology. After 6 days of induction, the cells exhibited inconsistent size and shape and aggregated centrally (D7, NEPs). With an additional 6 days of differentiation, cell morphology changed quickly, and the cells started to gather centrally to form rosettes (D13, MNPs, black arrow). On day 19, the differentiated MNs began projecting axons. The MNs matured gradually, and their axons elongated over time (D26, white arrow). The scale bar is 100 μm.

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