α-Synuclein dimerization in erythrocytes of Gaucher disease patients: correlation with lipid abnormalities and oxidative stress

Several observations suggest that disturbed homeostasis of alpha-Synuclein (alpha-Syn) may provide a link between Gaucher disease (GD) and Parkinson's disease (PD). We recently reported increased dimerization of alpha-Syn in the red blood cell (RBC) membrane of patients with GD. Several studies indicate a crucial relationship between lipids, oxidative stress and alpha-Syn status. Here we investigated the relationship between the observed increased dimerization of alpha-Syn in the cell membranes of RBCs, cells devoid of lysosomes and lacking lysosomal enzyme synthesis, and the lipid abnormalities and oxidative stress already described in GD. Correlation studies showed that in GD the alpha-Syn dimer/monomer ratio is positively correlated with the levels of glucosylceramide (GIcCer) and the glucosylceramide/ceramide (GlcCer/Cer) ratio and negatively with the levels of malonyldialdehyde (MDA) and plasmalogens. In conclusion, we have shown that the increased tendency of alpha-Syn to form dimers in the RBC membrane of patients with GD, is correlated with both the level of lipids, including GIcCer, the primary lipid abnormality in GD, and the increased oxidative stress observed in this disorder. The study of other tissues, and in particular brain, will be important in order to elucidate the significance of these findings regarding the link between GD and PD. (C) 2015 Elsevier Ireland Ltd. All rights reserved.