Introduction: Glucocerebrosidase 1 mutations, the most common genetic contributor to Parkinson's disease (PD), have been associated with decreased glucocerebrosidase enzymatic activity in PD patients with glucocerebrosidase 1 mutations (glucocerebrosidase 1-PD). However, it is unknown whether this decrease in enzymatic activity leads to lysosphingolipid accumulations.
Methods: The levels of hexosylsphingosines, globotriaosylsphingosine, sphingomyelin, and sphingomyelin-509 were measured in dried blood spots from glucocerebrosidase 1-PD patients (n = 23), sporadic PD patients (n = 105), Gaucher disease patients (n = 32), and controls (n = 88) by liquid chromatography-tandem mass spectrometry.
Results: Glucocerebrosidase 1-PD patients had increased hexosylsphingosine levels when compared with sporadic PD patients (P < .001) and controls (P < .0001). Hexosylsphingosine levels were increased in glucocerebrosidase 1 mutation carriers of glucocerebrosidase 1 (L444P; N370S; n = 11, P = .001) and glucocerebrosidase 1 polymorphic variants (E326K, T369M) associated with PD (n = 12, P = .04) when compared with controls.
Conclusions: Lysosphingolipid accumulations in PD patients who bear glucocerebrosidase 1 mutations suggest that substrate reduction therapy might be viewed as a possible strategy for glucocerebrosidase 1-PD treatment. © 2018 International Parkinson and Movement Disorder Society.
Keywords: GBA mutations; LC-MS/MS; Parkinson's disease; hexosylsphingosine; lysosomes; lysosphingolipids.
© 2018 International Parkinson and Movement Disorder Society.