Figure 6

Thioredoxin overexpression and ASK1 inhibition reduce Mn²⁺-mediated JNK phosphorylation via the thioredoxin/ASK1/MKK4 pathway.

(a) Representative western blot and bar chart showing the reduction in JNK phosphorylation mediated by thioredoxin transfection of Mn²⁺ and NH₄Cl treated S-DMT1 cells (compared to vector transfected cells, *p < 0.05, **p < 0.01, n = 4, Student’s t-test). Error bars represent standard error of mean (S.E.M.). (b) MTT assay of thioredoxin transfected S-DMT1 cells treated for 24 h with Mn²⁺ or Mn²⁺ with NH₄Cl (*p < 0.05, compared to corresponding vector transfected cells, n = 4). (c) Representative western blot and corresponding bar chart showing the reduction in MKK4 and JNK phosphorylation mediated by 12 h treatment with 10 μM ASK1 inhibitor NQDI-1 in S-DMT1 cells (*p < 0.05, **p < 0.01, ***p < 0.001, n = 4, Student’s t-test). β-actin was used as a control for equal loading.