Figure 8.

Determination of influence of VEGF on the MAPK signaling pathway. (A) Western blots showed the phosphorylation of Erk1/2 from L1–L5 segmental samples 8 weeks after the surgery; (B) Quantitative analysis revealed that the VEGF expression reduced after the surgery; treatment of the VEGFR inhibitor down-regulated the VEGF expression level in neonatal animals with ST, and the VEGF administration up-regulated its level in adult rats with injury; (C) Phosphorylation levels of Erk1/2 in adults decreased in response to ST, decreased by the inhibition of VEGF in P1 ST rats, but increased by the administration of VEGF in P28 ST animals (n = 3 biological replicates, ^*P < 0.05, ^**P < 0.01); (D) Phosphorylation level of Erk1/2 from 24 h of primary motoneuron culture was assessed by Western blot analysis; (E) Western blot quantitative analysis demonstrated that 0.4 nM VEGF can up-regulate the MAPK phosphorylation level, and inhibition of VEGF promoted the reduction MAPK/Erk1/2 phosphorylation level compared with the group treated with LPS (n = 20, ^*P < 0.05, ^**P < 0.01).