DT-Diaphorase Prevents Aminochrome-Induced Lysosome Dysfunction in SH-SY5Y Cells.

Aminochrome has been reported to induce lysosomal dysfunction by inhibiting the vacuolar H-type ATPase localized in lysosome membrane. DT-diaphorase has been proposed to prevent aminochrome neurotoxicity but it is unknown whether this enzyme prevents aminochrome-induced lysosomal dysfunction. In the present study, we tested the protective role of DT-diaphorase in lysosomal dysfunction by generating a cell line (SH-SY5YsiNQ7) with a stable expression of a siRNA against DT-diaphorase with only 10% expression of mRNA enzyme. The cells differentiated with retinoic acid and 12-o-tetradecanoylphorbol-13-acetate show a significant increase in the expression of tyrosine hydroxylase, vesicular monoamine transporter-2, and dopamine transporter. The incubation of SH-SY5YsiNQ7 cells with 10 μM aminochrome resulted in a significant decrease of lysosome pH determined by using acridine orange, while aminochrome has no effect on SH-SY5Y cells. These results support the proposed protective role of DT-diaphorase against aminochrome-induced lysosomal dysfunction.