Fig. 7

NT-3 upregulates c-Jun through the ERK pathway in Schwann cells. a The expression of ERK, p38, JNK, and their phosphorylation at different time points after the administration of NT-3 analyzed using western blotting. b–d Relative quantitative analysis of p-ERK/ERK, p-JNK/JNK, and p-p38/p38 show that NT-3 can only rapidly phosphorylate ERK. Data were normalized to 0 (control group). One-way ANOVA with Dunnett’s multiple comparisons test, ***P < 0.001, n = 3. e After common peroneal nerve transection, the distal nerve stump of the injury was denervated for 5 weeks and different doses of NT-3 were administered. After 4 h, the expression of ERK, JNK, and p38 and their phosphorylation were analyzed using western blotting. f–h Relative quantitative analysis of the expression of p-ERK/ERK, p-JNK/JNK, and p-p38/p38, Data normalized to the PBS group. One-way ANOVA with Dunnett’s multiple comparisons test, **P < 0.005, n = 3. i Western blot analysis of ERK, p-ERK, and c-Jun expression in the control, NT-3, NT-3 + DMSO, and NT-3 + PD98059 groups. j and k Relative quantitative analysis of p-ERK/ERK and c-Jun expression show that NT-3 can phosphorylate ERK and upregulate c-Jun, and PD98059 prevents the phosphorylation of ERK and upregulation of c-Jun caused by NT-3. The data were normalized to the control. One-way ANOVA with Tukey’s multiple comparison test, *P < 0.05, **P < 0.005, n = 3. All numerical data are presented as mean ± SEM