Objective: To comprehensively characterise the salivary proteome of patients with Parkinson’s disease (PD) and generate potential biomarker candidates for future studies.

Background: Saliva may be an ideal fluid for biomarker discovery in PD, given non-invasive collection methods. LC-MS/MS mass spectrometry is a powerful tool for biomarker candidate generation as it can quantify large numbers of proteins across a large dynamic range and permits hypothesis-free, data driven analysis.

Methods: We performed label-free LC-MS/MS mass spectrometry to comprehensively characterise the proteome of three patients with PD and a single age matched control. Quantification of proteins was performed based on spectral count data using DESeq (Differential Expression Analysis for Sequence count data). Protein Set Enrichment Analysis (PSEA) was used to determine whether sets of proteins related to different gene ontology terms were upregulated in the patient vs control saliva.

Results: A total of 70730 spectra corresponding to 527 different proteins were identified across all samples. Label-free quantification with DESeq revealed 15 proteins to be significantly increased in abundance and 7 proteins to be significantly decreased in the patient samples versus control (see Table 1, Fig 1). S100-A9 and S100-A8 had the lowest and second lowest q values for upregulation in the patient samples and were approximately 4.7 and 8 times more abundant in the patient samples than the control, respectively. PSEA revealed that across the entire proteome, there was an upregulation of protein sets related to the inflammatory response in the patient saliva.

Conclusions: To our knowledge, this is the first time that saliva from patients with Parkinson’s disease has been analysed by mass spectrometry. Our data may be useful for informing further biomarker discovery studies; for example, the proteins identified as upregulated could be taken forward for analysis in more targeted mass-spectrometry experiments with a larger sample size. The finding of an upregulation of proteins related to the inflammatory response supports previous suggestions that patients with PD may have a greater degree of inflammation in the oral cavity than healthy controls.

« Back to 2016 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/a-comprehensive-characterisation-of-the-salivary-proteome-of-patients-with-parkinsons-disease/