FIGURE 4.

Preventing JNK mitochondrial translocation and inhibiting JNK activity prevents 6-OHDA-induced cytotoxicity in SHSY5Y cells. A and B, SHSY5Y cells were treated with 25 μm 6-OHDA for 4 h, and JNK translocation in the presence or absence of 5 μm Tat-Sab or Tat-scramble peptide, JNK siRNA or Sab siRNA, or control siRNA was evaluated by Western blot analysis. Proteins (30 μg) were resolved by SDS-PAGE, and antibodies for JNK were used to detect proteins of interest in whole cell lysates. COX-IV or GAPDH was used as a loading control. C, SHSY5Y cells were treated with 25 μm 6-OHDA for 4 h, and cell death was monitored after 24 h by TUNEL analysis in the presence or absence of 500 nm SR-3306, 10 μm Tat-Sab or Tat-scramble peptide, JNK siRNA, Sab siRNA, or control siRNA. Significance (p < 0.05) between 6-OHDA-treated and 500 nm SR-3306 or 10 μm Tat-Sab, or JNK siRNA, or Sab siRNA- and 6-OHDA-treated groups is given by **. *, statistical significance (p < 0.05) between untreated group and DMSO-treated group. The results are from at least three biological replicate experiments, each performed in quadruplicate. IB, immunoblot.