Figure 2.

Effects of NT-4 on the mRNA levels of compact myelin proteins. (A) Schwann cells were exposed to NT-4 at the indicated concentration, and the mRNA level of MBP, MPZ, PMP22, and GAPDH was analyzed by real-time quantitative RT-PCR 12 h later. NT-4 significantly increased the MPZ mRNA level at the concentration of 150 ng/ml (n = 5, p = 0.002) and 300 ng/ml (n = 5, p = 0.013). (B) Expression of MBP, MPZ, and PMP22 was examined by western blotting analysis 12 h after NT-4 stimulation at the indicated concentration. A bar graph represents band intensities normalized to those for GAPDH. Each bar represents the average ± SEM of independent experiments. The MPZ protein level increased at the concentration of 150 ng/ml (n = 5, p = .001) and 300 ng/ml (n = 5, p = .001). *p < .05, **p < .01, compared with the control.