Fig 7. Neuroprotective effects of GDNF and VEGF in 4-HCM.

(A) C6 cells were treated with 250 μM of 4-HBA for 24 hrs and 4-HCM was collected and concentrated using a NANOSEP 10K filter. Primary neuronal cultures were treated with 200 μM of H₂O₂ for 30 min and LDH assays were carried out 24 hrs after H₂O₂ treatment. (B) Primary neuronal cultures were treated with 200 μM of H₂O₂ for 30 min and media were then replaced with 4-HCM. LDH assays were carried out 24 hrs later. (C-E) Primary neuronal cultures were pre-treated with 4-HCM for 4 hrs and then treated with 200 μM of H₂O₂ for 30 min. 4-HCM was pre-incubated with 1 μg/ml of anti-GDNF (C) or anti-VEGF (D) antibody or prepared from C6 cells transfected HO-1 siRNA (E). Non-specific IgGs and non-specific siRNA were used as negative controls. LDH assays were carried out 24 hrs after H₂O₂ treatment. Changes in cell death are presented as means±SEMs (n = 3). **p<0.01 versus the H₂O₂-treated control. VCM, vehicle-conditioned medium.