Figure 5.

NF1(−/−) Differentiating SCs Exhibited a Continuous High Proliferation Rate and a Lack of Myelinating Capacity

(A) Representative bright-field images after 20 days of differentiation from NC to SC for different NF1 genotypes. 3PNFiPS(−/−) and 5PNFiPS(−/−) cells exhibited a high cell density and the formation of 3D spheres. Scale bars, 50 μm.

(B) Macroscopic detail of sphere formation in 3PNiPS(−/−) and 5PNFiPS(−/−) cells during SC differentiation.

(C) Proliferation capacity of differentiating SCs. Representative immunofluorescence images of Ki-67 (green) at 7 and 30 days of differentiation. DAPI was used to stain cell nuclei. Scale bars, 50 μm.

(D) Quantification of Ki-67-positive cells (percentage over total DAPI-positive nuclei) expressed as the mean ± SE (n = 3 independent differentiation experiments). At least 300 nuclei were counted per time point and sample. ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001 (unpaired t test).

(E and F) Myelination capacity of control NF1(+/+) FiPS (E) and NF1(−/−) iPSCs (F). Myelination was assessed by co-culturing differentiated SCs (at 7 days) with rat DRG neurons for 30 days. SC myelination capacity was measured by immunostaining for TUJ1, S100b, and MPZ. Scale bars, 50 μm.

(G) PNF-derived SC immunostained with TUJ1, S100b, and MPZ. Scale bars, 50 μm.