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.

Evaluation of hbeta;D-1 and hbeta; D-2 levels in saliva of patients with oral mucosal diseases / Evaluación de los niveles de hbeta; D-1 y hbeta;D-2 en la Saliva de pacientes con enfermedades de la mucosa oral

OBJECTIVE: This study aimed to determine a possible correlation between oral mucosal disease and salivary concentrations of the antimicrobial peptides human beta-defensin-1 (hβD-1) and human betadefensin- 2 (hβD-2). METHOD: The present work focussed on the establishment of a reversed phase-high performance liquid chromatography (RP-HPLC) procedure to quantify human beta-defensins (hβD-1 and hβD-2) in saliva samples of patients with oral diseases such as lichen planus (n = 10), Behçet (n = 10) and recurrent apthous stomatitis (n = 10). RESULTS: Linear calibration range for hβD-1 and hβD-2 defensins was 1.67−200 µg mL-1 and 3.13− 100 µg mL-1 with R2 values of 0.9998 and 0.996, correspondingly. The concentration of beta-defensins in saliva was determined by comparing the peak areas of eluted hβD-1 and hβD-2 with that of their standards. The variation of the amount of beta-defensins was evaluated by comparisons of the results obtained from the patients with oral mucosal diseases before and after treatments and the control subjects. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.62 µg mL- 1 and 5.39 µg mL-1 for hβD-1 and 0.94 µg mL-1 and 3.13 µg mL-1 for hβD-2, respectively. CONCLUSION: The salivary beta-defensin concentration was significantly higher in patients with oral mucosal diseases than in healthy volunteers; furthermore, in patients with oral mucosal diseases, the concentration was significantly higher before treatment than after treatment.

OBJETIVO: Este estudio tuvo por objeto determinar una posible correlación entre la enfermedad de la mucosa oral y las concentraciones salivales de la beta-defensina humana 1 (hβD-1) y la beta-defensina humana 2 (hβD-2) de los péptidos antimicrobianos. MÉTODO: El presente trabajo estuvo encaminado al establecimiento de un procedimiento de cromatografía líquida de alta eficacia de fase reversa (RP-HPLC) para cuantificar las beta-defensinas humanas (hβD-1 y hβD-2) en muestras de saliva de pacientes con enfermedades orales como el liquen plano (n = 10), Behçet (n = 10), y la estomatitis aftosa recurrente (n = 10). RESULTADOS: El rango de calibración lineal de las defensinas hβD-1 y hβD-2 fue 1.67-200 µg mL-1 y 3.13-100 µg mL-1 con valores R2 de 0.9998 y 996, respectivamente. La concentración de beta-defensinas en la saliva se determinó utilizando el área de sus estándares. La variación de la cantidad de beta defensinas fue evaluada por comparaciones de los resultados obtenidos de los pacientes con enfermedades de la mucosa oral, antes y después de los tratamientos y los sujetos de control. Se halló que el límite de detección (LDD) y el límite de cuantificación (LDC) fueron 1.62 µg mL-1 y 5.39 µg mL- 1 para hβD-1 y 0.94 µg mL-1 y 3.13 µg mL-1 hβD-2, respectivamente. CONCLUSIÓN: La concentración de beta-defensina salival fue significativamente mayor en los pacientes con enfermedades de la mucosa oral que en los voluntarios sanos. Además, en pacientes con enfermedades de la mucosa oral, la concentración fue significativamente mayor antes del tratamiento que después del tratamiento.

Evaluation of hbetaD-1 and hbetaD-2 levels in saliva of patients with oral mucosal diseases.

OBJECTIVE: This study aimed to determine a possible correlation between oral mucosal disease and salivary concentrations of the antimicrobial peptides human beta-defensin-1 (hbetaD-1) and human beta-defensin-2 (hbetaD-2). METHOD: The present work focussed on the establishment of a reversed phase-high performance liquid chromatography (RP-HPLC) procedure to quantify human beta-defensins (hbetaD-1 and hbetaD-2) in saliva samples of patients with oral diseases such as lichen planus (n = 10), Behçet (n = 10) and recurrent apthous stomatitis (n = 10). RESULTS: Linear calibration range for hbetaD-1 and hbetaD-2 defensins was 1.67-200 microg mL-1 and 3.13 -100 PG mL-1 with R2 values of 0.9998 and 0.996, correspondingly. The concentration of beta-defensins in saliva was determined by comparing the peak areas of eluted hbetaD-1 and hbetaD-2 with that of their standards. The variation of the amount of beta-defensins was evaluated by comparisons of the results obtained from the patients with oral mucosal diseases before and after treatments and the control subjects. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.62 microg mL-Sand 5.39 microg mL-1 for hbetaD-1 and 0.94 mig mL-1 and 3.13 microg mL-1 for hbetalD-2, respectively. CONCLUSION: The salivary beta-defensin concentration was significantly higher in patients with oral mucosal diseases than in healthy volunteers; furthermore, in patients with oral mucosal diseases, the concentration was significantly higher before treatment than after treatment.

Expression of apoptosis regulatory proteins p53, bcl-2 and bax in recurrent aphthous ulceration.

BACKGROUND: Recurrent aphthous ulceration (RAU) is considered to be an acute inflammatory disease of unknown pathogenesis. Apoptosis may represent an important event in the control of inflammation. OBJECTIVES: The aim of this study was to investigate apoptosis process in RAU using immunohistochemistry. METHODS: We studied the expression and location of p53, bcl-2 and bax in ulcerated lesions clinically diagnosed as RAU (n = 12) and compared it with that of oral clinically normal mucosa (n = 6) and of other inflammatory chronic disease such as oral fibrous inflammatory hyperplasia (FIH; n = 18). RESULTS: Significant statistically differences (n < 0.05) in p53 expression were noticed in RAU when compared with normal mucosa. No significant statistically differences (P > 0.05) were noticed between FIH and RAU. Bcl-2 and bax did not show remarkable differences between groups. CONCLUSIONS: Taken together, the data suggest that RAU induces p53 immunoexpression. Therefore, the protein might be related to the aetiopathogenesis of the ulcerated oral lesions.

Association between recurrent aphthous stomatitis and salivary thiocyanate levels.

The aim of this work was to investigate the association between recurrent aphthous stomatitis (RAS) and salivary thiocyanate levels. The sample comprised men and women of age ranging from 15 to 55 years, who were allocated to four groups: 28 patients in RAS active phase (group 1); 28 patients in RAS remission phase (group 2); 29 smokers (group 3); 26 non-smokers without RAS (group 4). Samples of whole saliva mechanically stimulated were collected, and thiocyanate levels were measured. The results were analyzed by ANOVA and paired t-test. Mean salivary thiocyanate values were 0.55 mM, 0.64 mM, 2.36 mM and 0.96 mM in groups 1 (active RAS), 2 (remission RAS), 3 (smokers) and 4 (control), respectively. There was no significant difference in thiocyanate levels when groups 1 and 2 were compared with group 4. Group 3 showed a significantly higher thiocyanate concentration when compared with groups 1, 2 and 4 (P < 0.05). There was no significant difference in thiocyanate levels between groups 1 and 2 (P > 0.05). It is therefore suggested that there is no association between RAS and salivary thiocyanate levels.