Figure 1

Vinaxanthone inhibits Sema3A-induced growth cone collapse in isolated embryonic DRG neurons. Isolated neurons from E15 wildtype mice were incubated with NGF to induce neurite sprouts. After 24 h abundant neurites with well-developed axon growth cones were observed. Addition of Vinaxanthone does not induce neurite regression or collapse of the axon growth cones (A), while Sema3A rapidly induces collapse of the axonal growth cones (B). Pre-incubation of the neurons with Vinaxanthone for 1 h before adding Sema3A blocked the axonal regression effect due to Sema3A and neuronal growth continued (C). The treatment’s effects on neuronal growth and regression were recorded via time lapse images (see Supplementary Videos S1, S2 and S3 in Supplementary Information) and analyzed as described in “Materials and methods”. The 50% increase in axon growth cone collapse induced by Sema3A, was reduced to basal levels in the presence of 0.1 μg/mL Vinaxanthone (D). Data represent the mean ± SEM of four independent experiments, with approximately 100 neurons were evaluated per treatment, a P value < 0.05 was considered statistically significant between the treatments, arrows indicate the starting point for video recording of neurite elongation/regression and selected time frames show the treatment effect.