Aminochrome induces disruption of actin, alpha-, and beta-tubulin cytoskeleton networks in substantia-nigra-derived cell line.

In previous studies, we observed that cells treated with aminochrome obtained by oxidizing dopamine with oxidizing agents dramatically changed cell morphology, thus posing the question if such morphological changes were dependent on aminochrome or the oxidizing agents used to produce aminochrome. Therefore, to answer this question, we have now purified aminochrome on a CM-Sepharose 50-100 column and, using NMR studies, we have confirmed that the resulting aminochrome was pure and that it retained its structure. Fluorescence microscopy with calcein-AM and transmission electron microscopy showed that RCSN-3 cells presented an elongated shape that did not change when the cells were incubated with 50 muM aminochrome or 100 muM dicoumarol, an inhibitor of DT-diaphorase. However, the cell were reduced in size and the elongated shape become spherical when the cells where incubated with 50 muM aminochrome in the presence of 100 muM dicoumarol. Under these conditions, actin, alpha-, and beta-tubulin cytoskeleton filament networks became condensed around the cell membrane. Actin aggregates were also observed in cells processes that connected the cells in culture. These results suggest that aminochrome one-electron metabolism induces the disruption of the normal morphology of actin, alpha-, and beta-tubulin in the cytoskeleton, and that DT-diaphorase prevents these effects.