Protein Signature in Saliva of Temporomandibular Disorders Myalgia

Abstract

In the last years, several attempts have been made to study specific biological markers of temporomandibular disorders (TMD). So far, no laboratory tests have been appropriately validated for the diagnosis and prognosis of these disorders. This study aimed to investigate the proteomic profile of the whole stimulated saliva of TMD myalgia patients in order to evaluate potential diagnostic and/or prognostic salivary candidate proteins which could be useful for the management of TMD. Twenty patients diagnosed with TMD myalgia according to the validated Diagnostic Criteria for TMD (DC/TMD) and 20 matched healthy pain-free controls were enrolled. Saliva samples were collected in the morning. Comparative proteomic analysis was performed with two-dimensional gel electrophoresis followed by identification with liquid chromatography-tandem mass spectrometry. Statistical analysis of the quantitative proteomics data revealed that 20 proteins were significantly altered in patients compared to controls. Among these proteins, 12 showed significantly increased levels, and 8 showed significantly decreased levels in patients with TMD myalgia compared to controls. The identified proteins are involved in metabolic processes, immune response, and stress response. This proteomic study shows that the salivary protein profile can discriminate patients with TMD myalgia from healthy subjects, but the protein signature has no correlation with the clinical features of TMD myalgia. Additional studies are needed to validate our observations in additional sample sets and to continue assessing the utility of saliva as a suitable sample for studying processes related to TMD myalgia.

Myogenous temporomandibular disorders and salivary markers of oxidative stress—A cross‐sectional study

“…The proteomic analysis revealed several proteins associated with the immune system, stress response and metabolism that were dysregulated in TMDM. 18 Our present study confirms that this is also the case for oxidative stress markers.…”

“…[24][25][26][27][28][29] We have previously analysed the levels of pain-associated markers, and the proteomic profile of plasma and saliva from healthy volunteers and individuals with TMDM. 18,24,30 These studies suggest that stimulated whole saliva is a valuable medium to measure markers of pain in these pathologies. The proteomic analysis revealed several proteins associated with the immune system, stress response and metabolism that were dysregulated in TMDM.…”

“…In addition, in our proteomic study, performed in a subgroup of the samples used in the present investigation, levels of antioxidant proteins thioredoxin and S100-A8 were lower as opposed to the increased TAC. 18 These diverging results suggest that the collection method for whole saliva is not relevant for the quantification of oxidative stress markers and that antioxidant activity can be higher even when the number of antioxidants seems to be lower (at least at proteomic level).…”

“…For a full description of the methodology, see Jasim et al 18 In brief, from June 2017 to April 2019, individuals with TMDM were recruited from patients referred to the Specialist Clinic for Orofacial Pain and Jaw function, University Dental Clinic, Karolinska Institutet, Huddinge, Sweden; together with healthy and pain‐free volunteers who responded to public advertisement or were undergraduate dental students at the same institution. Sample sizes from the original study were calculated based on data from similar studies at the department, considering two groups, a difference of 1.5 SD, a statistical power of 0.8 and statistical significance of P < .05, which yielded a sample size of 37 in each group.…”

“…After the clinical examination, if the participants met the requirements, whole stimulated saliva was collected. 18 All samples were obtained at the same time range, between 7:30 am and 12:00 pm. In brief, the participants were instructed to rinse their mouth during…”