Generation of Otic Lineages from Integration-Free Human-Induced Pluripotent Stem Cells Reprogrammed by mRNAs

Figure 3

(a) Diagram showing the protocol for the generation of hair cell-like cells. (b) qPCR showing relative expression levels of the hair cell markers POU4F3 and MYO7A. Data shown as fold change against undifferentiated cells from the same initial population. (c) ATOH1 and POU4F3 proteins are coexpressed by some cells. Immunofluorescence images shown are from cell line MIFF1. Scale bar, 200 μm (d). Electrophysiological properties of differentiating hair cell-like cells. To investigate the presence of outward and inward K⁺ currents, cells were recorded using the same voltage protocol described in Figure 2. Outward K⁺ currents were observed in 10 out of 12 hair cell-like cells; these currents were either an inactivating A-type K⁺ current ( pA at 0 mV, out of 10 cells (d)) or a delayed rectifier current ( pA at 0 mV, out of 10 cells (f)). Inward K⁺ currents (: pA near -124 mV) were observed in 4 out of 12 hair cell-like cells ((e) holding potential -64 mV, same as the cell in (d)).

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