Figure 3

STAT3 phosphorylation is impaired in DRG in diabetes and enhanced by IL-1β in neuron cultures. In (a) is shown Western blot of DRG samples from control and 5 month STZ-diabetic mice. In (b) expression levels are indicated and are presented relative to T-ERK or T-STAT3 and are means ± SEM (n = 3–4 mice) *P < 0.05 vs control. In (c and e), are shown representative Western blots of DRG from normal or diabetic rats cultured for 1 day at low dose of neurotrophic growth factors and stimulated for 30 minutes with IL-1β at (10 ng/ml). In (d and f) are bar charts showing levels of phosphorylation of STAT3 on Ser-727 (Ser) or Tyr-705 (Tyr) presented relative to total ERK or total STAT3. *P < 0.05 vs untreated. Values are mean ± SEM, n = 4 (two-way ANOVA with Bonferroni’s test). Bar charts b, d, and e also show total STAT3 levels relative to T-ERK.