Fig. 1

ALS iPSC conditioned medium (CM) is neuroprotective for ALS-MNs. a The effect of ALS iPSC-CM on viability and apoptosis in ALS-MNs. The viability of ALS-MNs exposed to H₂O₂ was measured by MTT assay. The ratio of apoptotic to live ALS-MNs was assayed by Annexin V fluorescence in a plate reader. n = 4, *P < 0.05. b The time course of viability (560/590 nm) and apoptosis (490/590 nm) of MNs that were pre-treated or post-treated (H₂O₂ first, then ALS iPSC-CM) with ALS iPSC-CM. c Representative images of MNs at 30 days and 60 days. WT, WT iPSC differentiated into MNs; ALS CS53, ALS iPSC differentiated into MNs; ALS CS53 + CM, iPSC differentiated into MNs in the presence of ALS iPSC CM. Scale bar, 200 μm. d Experimental schematic. The CMs from WT-iPSC, ALS-iPSC, and iPSCs-derived fibroblasts (dF-CM) were used to treat the differentiating MN cultures on days 30–60, after which MN assays were performed. e The neurite size was measured during MN differentiation from hESC, iPSC and ALS-iPSCs (± autologous ALS iPSC-CM on days 30, 35, 40, 45, and 50). ALS-MN neurites (CS53 and CS07) were maintained by ALS iPSC-CM when treatment started on day 30 or 35, but not on later days. For the negative control dF-CM, there were no cells that maintained neurites. Mean ± SEM, experiments were repeated with four independently derived MN cell lines from ALS hiPSCs (i.e., n = 4). *P < 0.05. f The net change of neurite size was examined during differentiation of ALS-MNs treated with autologous ALS iPSC-CM, as indicated. g Left, the percent of cleaved caspase-3 (CC3)-positive cells was quantified during this directed differentiation of MNs. Right, representative images of CC3 (green)-positive MNs with DAPI staining of cell nuclei (blue). Mean ± SEM, n = 5. *P < 0.05, **P < 0.01, ***P < 0.001. Scale bar, 100 μm