Figure 6

p70S6K1 activity correlates with and regulates the onset of MBP expression in primary rat OPCs in vitro. (A–D) Immunostaining for MBP (green) and pS6RP (pink) in primary rat OPCs after 3 days (A and B) or 5 days (C and D) of differentiation in the absence (A and C) or presence (B and D) of PF-4708671 (10 µM). Nuclei are stained with Dapi (blue). (E–G) Graphs indicating the percentage of cells at each timepoint that were MBP⁺ (E), pS6RP⁺ (F) and MBP⁺PS6RP⁺ (G). (H) Immunostaining for pS6RP after 5 days in control differentiation media (same image as panel C) showing both bright (brt) and low or diffuse staining for pS6RP. (I) Graph indicating percentage of PS6RP⁺ cells at each timepoint that was bright. (J) Graph indicating percentage of MBP⁺ cells at each timepoint that were also PS6RP⁺. An unpaired two-tailed t-test with Welch's correction if variances are unequal: *P < 0.0001 for all graphs with the exception of panel E (3 days, P = 0.0272 and 5 days, P = 0.0049). Scale bars (A–D and H), 100 µm.