Figure 2. Autophagy induction promotes melanogenesis.
(a,b) Melan-a melanocytes were treated with indicated concentration of rapamycin (Rap) or PP242 for 24 h and analyzed by Western blotting with antibodies against LC3, beclin-1, ATG5, p62, MITF, PMEL17, tyrosinase, and β-actin. Quantitative densitometry of protein expression compared to β-actin is shown. To determine the effect of autophagy activation on melanogenesis, cells were assayed for melanin content (c) and tyrosinase activity (d). The effect of Rap and PP242 on cell proliferation (e) and viability (f) was determined at 24 h post-treatment. All results shown are the mean of three independent experiments ± SD. *P < 0.05 versus untreated controls.