Screening The Autoantigen In Substantia Nigra Related To Parkinson’s Disease Pathogenesis

Background: Parkinson’s disease (PD)which also called "shaking palsy"， is thecommon degeneration disease of the central nervous system. It is characterized by the statictremor, bradykinesia, rigidity and postural reflex impairment. The special damage ofdopamine neuron is the important characteristic of PD. In recent years, some researchessuggest that there are some autoantibodies in the PD patients’ serum and spinal fluid whichmay be involved in the damage of dopamine neurons. However, the mechanism is not clear.According to the recent studies, the proteins in the substantia nigra may be the targetproteins which are attacked by the autoantibodies in the humoral immune, but we still donot know which proteins are. For that reason, we seek the different proteins between the PDpatients and normal peoples and identify these so that we can preliminarily screen theautoantigens which are associated with the mechanism of PD. The aim of this article is toascertain the target proteins that are related with the PD in the substantia nigra. And then itcan further illustrate the role of humoral immune in PD mechanism and provide new ideasand new strategies for Parkinson’s disease immune treatment and diagnosis.Objective: To explore the role of the humoral immune in Parkinson’s disease(PD)pathogenesis and to establish the principle and experiment foundations for the betterunderstanding and revealing Parkinson’s disease pathogenesis and immune therapy, wescreen and identify the autoantigens which are associated with the mechanism of PD in thesubstantia nigra.Methods: The serums were collected from10clinically diagnosed PD patients and10normal volunteers. And then, the serum IgGs were separated by the immune affinitychromatography. After the membrane proteins and cytoplasm proteins were separated inthe substantia nigra from normal SD rats, the proteins that interacted with serum IgG werescreened out by western blot and immune precipitation. In order to seek the differencesbetween the PD patients and normal volunteers, the differential proteins were isolated by the SDS-PAGE Assay and were subjected to mass spectrometry and bioinformatics analysis.Results:(1) The serum IgG could only combine with the membrane proteins in thesubstantia nigra between the two groups and not combine with the cytoplasm proteins.(2) Through the Western blot, we preliminarily analyse the membrane proteins whichcombine with the serum IgG in the substantia nigra between the PD patient and normalvolunteers. According to this method, there was no obviously and uniformly specialdiffernence between these two groups.(3) Through the immunoprecipitation, we found one differential lineation whichapproximate molecular weight was60Kda.(4) Using HPLC-IRON-TRAP-MS/MS and bioinformatics analysis, we obtained twocandidate proteins: alpha-tubule protein and cytokeralin.Conclusion: The target proteins in the construction of the substantia nigra whichcombined with the PD patients’ serum antibodies are membrane proteins. Compared withthe normal volunteers, the PD patients’ serum IgG and the membrane protein combinationexisted some differences. This study suggested that the combination of some specificproteins which existed in the construction of the substantia nigra and serum antibodiesmight participate in the development of the PD.