α-Synuclein (αSN) has been implicated in Parkinson's Disease (PD) and αSN is a major component of Lewy bodies (LBs). This study explored platelets as a model system for study of αSN metabolism and platelet αSN as a diagnostic marker for PD. We used Western blot analysis to characterize and compare platelet and brain α-, β- and γSN; and to quantitate αSN levels in platelets from PD and age-matched controls. We found that platelets contain full-length αSN and 6 and 12 kDa fragments, and γSN-like protein. αSN and γSN were not secreted by thrombin-activated platelets. Furthermore, we also found that the αSN and γSN levels in sporadic PD patients and age-matched normal controls were not significantly different. This indicates that platelet αSN or γSN is not a suitable peripheral diagnostic marker for PD. Platelets may be used for study of αSN and γSN metabolism, and may give some broad insight into the normal functions of αSN and γSN.
- Parkinson's disease