Effects of specific gangliosides on the in vitro proliferation of MPTP-susceptible cells.

To determine which portion of a ganglioside molecule might be necessary for the enhancement of recovery from MPTP-induced lesions, the ability of specific gangliosides to stimulate proliferation of MPTP-treated 140-3 cells was investigated. The results indicate that of the gangliosides tested, GM1 was the most effective. Although GD1a and GT1b were able to enhance the proliferation of MPTP-treated cells, twice as much GT1b was needed to induce the same effect seen with GM1. In contrast, asialo-GM1, GM2, and GM3 were ineffective at promoting proliferation of MPTP-treated cells. The isolated oligosaccharide of GM1 had little effect. These results indicate that in addition to the sialosyl residue, at least the Gal(beta 1-3)Gal-NAc portion of the oligosaccharide chain and the ceramide moiety are essential for the induction of proliferation of the MPTP-treated cells. Investigation of the time of addition of GM1 on its ability to counteract the MPTP-induced inhibition of 140-3 cell proliferation indicated that addition of GM1 before or concomitantly with MPTP resulted in a significant reduction in MPTP-induced inhibition of cell proliferation.