FIG. 3.

DJ-1 protein level is decreased without a change in mRNA level in CATH.a cells exposed to MPP⁺ or rotenone. (A) Representative photomicrographs of Western blot analysis showing MMP3 and DJ-1 levels in CATH.a cells exposed to MPP⁺ (200 and 300 μM) for 24 h. (actMMP3, active form of MMP3; c-terminal, antibody against C-terminal epitopes of DJ-1; n-terminal, antibody against N-terminal epitopes of DJ-1; proMMP3, pro-form of MMP3). (B) The intensity of each band was determined densitometrically and normalized against β-actin. Expression levels are depicted as percent increase relative to the corresponding untreated control. **p < 0.01; ***p < 0.001 vs. control. (C) Representative photomicrographs of Western blot analysis showing MMP3 and DJ-1 levels in CATH.a cells exposed to rotenone (100 and 200 nM) for 24 h. (D) The intensity of each band was determined densitometrically and normalized against β-actin. (E) Cytosolic fraction of CATH.a cells exposed to MPP⁺ was co-immunoprecipitated with anti-MMP3 antibody, then DJ-1 was detected using Western blot analysis. (F) A representative PCR of DJ-1 mRNA in CATH.a cells treated with 300 μM MPP⁺ for 6 h. (G) Real-time PCR confirmed DJ-1 level was not changed by MPP+ treatment. DJ-1 expression level has been normalized against an internal control, GAPDH, and is expressed as fold change of untreated control.