FIGURE 3.

Inhibition of mitochondrial JNK signaling and JNK activity prevents 6-OHDA-induced ROS generation, mitochondrial dysfunction, and changes in OCR and ATP levels in SHSY5Y cells. A, SHSY5Y cells were treated with 25 μm 6-OHDA for 12 h, and mitochondrial ROS was measured by normalized Mitosox fluorescence in the presence or absence of 50 nm SR-3306, 500 nm SR-3306, 10 μm Tat-Sab or Tat-scramble peptide, JNK siRNA, Sab siRNA, or control siRNA. B, same as in A except mitochondrial membrane potential was measured by normalized JC-1 fluorescence after 18 h 6-OHDA stress. C, same as in A except OCR was measured in a Seahorse XF-96 analyzer after 12 h of 6-OHDA stress. D, same as in A; ATP levels were monitored by ATP determination kit (Invitrogen) after 12 h of 6-OHDA stress. Significance (p < 0.05) between 6-OHDA-treated groups and between 500 nm SR-3306, 10 μm Tat-Sab or JNK siRNA, or Sab siRNA and 6-OHDA-treated groups is shown by *. **, statistical significance (p < 0.05) between control treatment group and treated group. The results are from at least three biological replicate experiments, each performed in quadruplicate.