4 phenylpyridine

The mice were euthanized 90, 120, or 240 min post MPTP injection. The striata were dissected, immediately frozen, and stored at − 80 °C until ready for analysis. On the day of the assay, the tissue samples were sonicated in 10 vol of 5% tricholoracetic acid containing 5 μg/ml of 4-phenylpyridine (Sigma, USA) as the internal standard. The samples were centrifuged at 3000g for 10 min and then 20 μl of the supernatant was injected onto a cation-exchange Ultracyl-CS column (Waters chromatographic system, Japan). The mobile phase consisted of 90% a solution with 0.1 M acetic acid and 75 mM triethylamine-HCl (pH 2.35 adjusted with formic acid), and 7% acetonitrile. The flow rate was 1.5 ml/min. An external calibration curve was used to express the final amount in the tissue sample as microgram per gram (μg/mg) wet tissue for MPP⁺.

4‐phenylpyridine was purchased from Sigma Aldrich (Sigma Aldrich, St. Louis, USA). Dulbecco's Modified Eagle Medium (DMEM), penicillin–streptomycin and fetal bovine serum (FBS) were from Thermo Scientific HyClone (Thermo Scientific HyClone, Logan, USA). Antibodies to β‐actin (1:1000, sc‐517,582) and c‐Src (B‐12) (1:1000, sc‐8056) were purchased from Santa Cruz Biotech (Santa Cruz Biotechnology, CA, USA). Antibodies specific for COX‐2 (1:1000, #12282), c‐Jun (1:1000, #9165), p‐c‐Jun (1:1000, #3270), α/β‐tubulin (1:1000, #2148), p38 MAPK (1:1000, #8690), phospho‐p38 MAPK (Thr180/182) (1:1000, #4511), SAPK/JNK (1:1000, #9252), phospho‐SAPK/JNK (Thr183/Tyr185) (1:1000, #4668), p44/42 MAPK (Erk1/2) (1:1000, #4695), phospho‐p44/42 MAPK (Erk1/2) (Thr202/Thr204) (1:1000, #4370), p‐Akt (S473) (1:1000, #9271), Akt (1:1000, #9272), MKK3/6 (1:1000, #9238), p‐MKK3/6 (1:1000, #9231), MKK4/7 (1:1000, #9152), p‐MKK4/7 (1:1000, #9156), MEK1/2 (1:1000, #9122), p‐MEK1/2 (1:1000, #9121), p‐Src (Y416) (1:1000, #6943), p‐EGFR (Y845) (1:1000, #2231), p‐EGFR (Y1068) (1:1000, #3777), p‐EGFR (Y1045) (1:1000, #2237) and EGFR (1:1000, #4267) were purchased from Cell Signalling Biotechnology (Cell Signalling Biotechnology,). Anti‐lamin B1 (1:10000, ab 16,048) was purchased from Abcam (Abcam).