Proteomic study of salivary peptides and proteins in patients with Sjögren's syndrome before and after pilocarpine treatment

Abstract

Objective. To investigate the effect of pilocarpine on the salivary peptide and protein profile in patients with primary Sjögren's syndrome (SS) and to study the differences between patients with primary SS, patients with SS associated with other rheumatic diseases, and healthy control subjects.Methods. Saliva specimens were obtained from 9 primary SS patients, 9 secondary SS patients, and 10 healthy controls. Samples were analyzed for levels of 62 different salivary proteins using high-performance liquid chromatography coupled with mass spectrometry using a spectrometer equipped with an electrospray ionization source. In 6 of the primary SS patients, saliva was collected at 30 minutes, 60 minutes, and 24 hours after taking 5 mg of pilocarpine.Results. Before pilocarpine, ϳ60% of salivary proteins in samples from primary SS patients were not identifiable or showed lower levels than those in healthy controls. After 30-60 minutes following pilocarpine treatment, approximately one-third of the less represented proteins was found in a similar percentage of primary SS patients and controls. Almost all of the proteins that were detectable at lower levels in primary SS patients compared with controls reached levels similar to those in controls at 30-60 minutes after pilocarpine. The parotid gland proteins had the best response to pilocarpine. Primary SS patients were characterized by higher ␣-defensin 1 levels and by the presence of ␤-defensin 2. Secondary SS patients showed an intermediate protein profile between that of the primary SS patients and the controls. Conclusion. Pilocarpine partially restored the levels and numbers of identifiable proteins in saliva from patients with primary SS. Higher levels of ␣-defensin 1 and the presence of ␤-defensin 2 in the saliva of patients with primary SS could be markers of oral inflammation in this patient group.Saliva is a complex fluid composed of a variety of electrolytes, metabolites, nucleotides, polynucleotides, and proteins. This fluid plays an important role in the maintenance of oral health. The rate of salivary protein secretion is controlled mainly by noradrenaline, which is released from the sympathetic terminals and acts through the ␤-adrenergic receptors. The rate of fluid and electrolyte secretion is controlled by acetylcholine, which is released from the parasympathetic terminals and acts through the muscarinic cholinergic receptors.A large number of systemic agents have been proposed as secretagogues, but only a few have shown consistent salivary secretion-enhancing properties in well-designed trials. Among cholinergic agonists, studies in rats have shown that pilocarpine is the most effective for protein secretion (1) and has mild ␤-adrenergic stimulatory properties; however, few data in humans have been reported. Pilocarpine has been shown to improve symptoms of oral dryness and to increase salivary output in patients with primary Sjögren's syndrome (SS) (2), a chronic autoimmune disorder of the exocrine glands with associated lymphocytic infiltrates and con...

Establishment of a novel diagnostic model for Sjögren’s syndrome by proteomic fingerprinting

“…Based on mass spectrometric screening, peptidome analysis is able to complete high throughout proteomic profiling within only a few hours [15,16], which could provide possible solutions of multiple biomarker detection for disease diagnosis. There are several studies performed essentially by analyzing saliva, tears, and salivary gland tissue in pSS [17][18][19][20][21][22]. Driss et al [23] identified a 7,606-Da biomarker peptide unique to the salivary samples from the SS subjects.…”

Sjögren’s Syndrome: The Proteomic Approaches

“…Six studies have been performed in SS, and they are quite different in their principal goals as well as in their general methodologies (Ryu et al, 2006;Hu et al, 2007b;Peluso et al, 2007;Flesseig et al, 2009;Hu et al, 2011). Whole saliva or individual glands saliva have been examined, and samples were collected both in stimulated and unstimulated conditions.…”

“…Peluso and colleagues (Peluso et al, 2007) analysed the differences in the salivary protein profiles of primary SS and secondary SS patients, and of control subjects using HPLC-ESI-MS. The authors collected whole saliva specimens from 9 primary SS patients, 9 secondary SS patients (3 Rheumatoid Arthritis-2° SS; 3 systemic sclerosis-2° SS; 3 systemic lupus erythematosus-2° SS), and 10 healthy controls, and they analysed the levels and frequencies of 62 proteins.…”

The Current Status and Future Prospects of the Salivary Proteome

“…Therefore, changes to the saliva proteome provides information about the whole body and oral health: whole saliva contains proteins that can be informative for disease detection in oral health, [4][5][6][7][8][9][10][11] in particular for oral cancer, 12) head and neck squamous cell carcinoma 13) and Sjögren's syndrome. [14][15][16] Saliva, as a diagnostic fluid, has received a lot of attention recently, due to its relatively simple and non-invasive collection, 2) which is an important advantage, especially in sample collection from children and elderly people. In this review, we summarize current knowledge about the salivary proteome using mass spectrometry (MS) based technologies.…”