Salivary proteins offer insights into keratinocyte death during aphthous stomatitis. A case-crossover study.

BACKGROUND: The death of oral keratinocytes is a crucial step in the emergence of recurrent aphthous stomatitis (RAS, also known as aphthae or aphthous ulcers). Since there are no experimental models available to research aphthous ulcers, little is understood about this process. We hypothesize that saliva can be a data bank of information that offers insights on epithelial damage. METHODS: In this case-crossover study, we assessed the salivary proteome of patients with RAS (n = 36) in the presence and absence of ulcers using discovery proteomics and bioinformatics. Additionally, we contrasted these patterns with those of healthy individuals (n = 31) who had no prior aphthous ulceration. RESULTS: Salivary proteome showed that during the ulcerative phase, controlled cell death was downregulated. Due to its ability to distinguish between individuals with and without ulcers, the ATF6B protein raises the possibility that endoplasmic reticulum (ER) stress is responsible for the damage that leads to the death of oral keratinocytes. The high abundance of TRAP1 and ERN1 matches with this biological discovery. The type of death is immunogenic, according to the functional data found in a cell death database. CONCLUSION: We identified a cellular process that can lead to the death of oral keratinocytes in the etiopathogenesis process of RAS. Future studies should be conducted to identify what is responsible for the increase in ER stress signaling that would lead to an anti-cell death response.

Recurrent Aphthous Stomatitis Affects Quality of Life. A Case-Control Study.

Aim: To determine the impact of recurrent aphthous stomatitis on quality of life related to oral health, and then to determine the relationship between the observed impact and lesions characteristics. Methods: In this prospective case-control study (n=62), patients were divided into a healthy group (people with no history of ulcers) and recurrent aphthous stomatitis (people who had an active ulcer at study entry). The latter were also evaluated when the lesion disappeared (remission stage). We record the quality of life in all groups using the impact profile of oral health in its abbreviated Spanish version (OHIP-14SP). Finally, we correlate the clinical characteristics of the lesions with the levels of quality of life. Results: All the lesions were of the minor morphological type. Most of the lesions were located on the lining mucosa, primarily on the lips. Patients report a lower quality of life during ulcer episodes compared to ulcer-free periods, and this impact is positively related to the number and size of lesions. Conclusion: We concluded that recurrent aphthous stomatitis increased the negative effects of oral health on the quality of life of patients. The number and size of ulcers are responsible for this impact. Our results suggest that, if intervened locally, general relief of the condition could be achieved.

Salivary proteome of aphthous stomatitis reveals the participation of vitamin metabolism, nutrients, and bacteria.

There are currently no preventative options for recurrent aphthous stomatitis, and the only available treatments are palliative. This is partly due to a poor understanding of its etiopathogenesis. In this case-control study, we characterized the salivary proteome of patients with recurrent aphthous stomatitis in the presence and absence of lesions. Through mass spectrometry-based proteomics and bioinformatics tools, we identified that the presence of oral ulcers is associated with several specific biological processes, including the metabolic pathways of vitamin B9, B12, nitrogen, selenium, and the bacterium Neisseria meningitidis. These changes occurred only in the presence of clinically visible lesions, and there were no relevant differences between patients in anatomical regions unaffected by ulcers. Additionally, using western blot and ELISA assays, we verified that carbonic anhydrase 1 (CA1) and hemoglobin subunit beta (HBB) proteins are highly expressed during the ulcerative and remission phases of recurrent aphthous stomatitis. Our results cumulatively support saliva as an indicator of the pathophysiological changes, which occur during the clinical course of lesions. From a clinical perspective, we suggest that recurrent aphthous stomatitis is a condition triggered by temporary biological changes in people with lesions.