EFFECTS OF SPECIFIC GANGLIOSIDES ON THE IN-VITRO PROLIFERATION OF MPTP-SUSCEPTIBLE CELLS

To determine which portion of a ganglioside molecule might be necessar y for the enhancement of recovery from MPTP-induced lesions, the abili ty of specific gangliosides to stimulate proliferation of MPTP-treated 140-3 cells was investigated. The results indicate that of the gangli osides tested, GM1 was the most effective. Although GD1 a and GT1b wer e able to enhance the proliferation of MPTP-treated cells, twice as mu ch GT1b was needed to induce the same effect seen with GM1. In contras t, asialo-GM1, GM2, and GM3 were ineffective at promoting proliferatio n of MPTP-treated cells. The isolated oligosaccharide of GM1 had littl e effect. These results indicate that in addition to the sialosyl resi due, at least the Gal(beta1-3)Gal-NAc portion of the oligosaccharide c hain and the ceramide moiety are essential for the induction of prolif eration of the MPTP-treated cells. Investigation of the time of additi on of GM1 on its ability to counteract the MPTP-induced inhibition of 140-3 cell proliferation indicated that addition of GM1 before or conc omitantly with MPTP resulted in a significant reduction in MPTP-induce d inhibition of cell proliferation.