Analysis of cerebrospinal fluid protein expression in Parkinson's disease by two-dimensional difference gel electrophoresis

Objective To identify differentially expressed proteins in cerebrospinal fluid (CSF) of Parkinson's disease (PD), so as to provide clues for investigating PD biomarkers. Methods Two-dimensional difference gel electrophoresis (2D DIGE) technique, in combination with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), was used to determine the differentially expressed CSF proteins in PD patients in comparison with control subjects. Results The levels of 20 protein spots were significantly altered in PD CSF. Of them, 11 spots were up-regulated and 9 spots were down-regulated. Of the 8 proteins identified in the profile of differentially expressed protein spots between patients and controls, an isoform of apolipoprotein A-I, myosin phosphatase target subunit 1 (MYPT1), and 3 unknown proteins were down-regulated, whereas an apolipoprotein A-I isoform, proapolipoprotein, and lipoprotein were up-regulated. Conclusions MYPT1 is related with synapse function and proapolipoprotein, lipoprotein and apo A-I are associated with cholesterol metabolism. These proteins may have links with the pathogenesis of PD and may be identified as CSF biomarks in PD. Key words: Parkinson's disease;  Cerebrospinal fluid;  Biomarker;  Proteomics