Differential expression of FSTL1 and its correlation with the pathological process of periodontitis.

AIMS: This study aimed to elucidate the alterations in Follistatin-like protein 1 (FSTL1) and its association with the pathological process of periodontitis. METHODS: This study included 48 patients with periodontitis and 42 healthy controls. The expression level of FSTL1 in the gingiva was determined by RT-qPCR, validated using the dataset GSE16134, and subsequently examined by western blotting. Bioinformatics analysis revealed a single-cell distribution of FSTL1, characteristic of angiogenesis and immune cell infiltration. The expression and distribution of FSTL1, vascular endothelial marker protein CD31 and myeloperoxidase (MPO), the indicator of neutrophil activity, were determined by immunohistochemistry (IHC). A series of correlation analyses was performed to determine the associations between FSTL1 and clinical parameters, including probing depth (PD) and clinical attachment loss (CAL), and their potential role in angiogenesis (CD31) and neutrophil infiltration (MPO). RESULTS: FSTL1 was significantly upregulated in the gingiva of patients with periodontitis compared to their healthy counterparts. In addition, FSTL1 was positively correlated with the clinical parameters PD (r = .5971, p = .0005) and CAL (r = .6078, p = .0004). Bioinformatic analysis and IHC indicated that high FSTL1 expression was significantly correlated with angiogenesis and neutrophil infiltration in periodontitis. Moreover, receiver operating characteristic (ROC) analysis demonstrated that FSTL1 could serve as an independent indicator for evaluating the severity of periodontitis (area under the curve [AUC] = 0.9011, p < .0001). CONCLUSION: This study demonstrated FSTL1 upregulation in periodontitis and its potential contribution to the disease via angiogenesis and neutrophil infiltration.

Role of αENaC in root resorption of adjacent teeth due to entirely impacted mandibular third molars.

BACKGROUND: Entirely impacted mandibular third molar (EIM3M) concerns the pathological external root resorption (ERR) of the adjacent mandibular second molar (M2M) and formation of granulation tissue between two molars. The study aimed to clarify the effect of αENaC, a mechano-sensitive molecule, to explore the mechanical mechanism in this scenario. METHODS: The force EIM3M exerted on M2M was proved by finite element analysis. αENaC expressions were tested by real-time polymerase chain reaction (PCR), immunoblotting and immunofluorescence. Inflammatory and epithelial-mesenchymal transition (EMT)-related molecules expressions were also detected by real-time PCR. The correlation was analyzed by Spearman's correlation analysis, and receiver-operator characteristic (ROC) curve was further exhibited. RESULTS: The force was concentrated in the ERR area. αENaC was upregulated, positively correlated with ERR degree and localized to the fibroblasts in ERR granulation tissues. Moreover, αENaC was respectively and positively associated with elevated TNF-α and N-cadherin in ERR granulation tissues. More importantly, ROC analysis verified αENaC as a novel indication of the incidence of this disease. CONCLUSIONS: Our finding revealed the force from EIM3M causing ERR of M2M, and elucidated the expression and localization of αENaC and its positive correlation with inflammation, EMT and disease severity, suggesting a novel indication in this disease.

Expression patterns of mechanosensitive ion channel PIEZOs in irreversible pulpitis.

BACKGROUND: Mechanosensitive ion channel PIEZOs have been widely reported to involve inflammation and pain. This study aimed to clarify expression patterns of PIEZOs and their potential relations to irreversible pulpitis. MATERIALS AND METHODS: Normal pulp tissues (n = 29) from patients with impacted third molars and inflamed pulp tissues (n = 23) from patients with irreversible pulpitis were collected. Pain levels were assessed using a numerical rating scale. PIEZO expressions were measured using real-time PCR and then confirmed using GEO datasets GSE77459, immunoblot, and immunohistochemistry staining. Correlations of PIEZO mRNA expression with inflammatory markers, pain markers, or clinical pain levels were evaluated using Spearman's correlation analysis. Univariate analysis was conducted to analyze PIEZO expressions based on pain description and clinical examinations of cold test, percussion, palpation, and bite test. RESULTS: Compared with normal pulp tissues, mRNA expression levels of PIEZO1 were significantly increased in inflamed pulp tissues, while PIEZO2 was significantly decreased, which was further confirmed in GSE77459 and on a protein and histological level. The positive correlation of the mRNA expression levels between PIEZO1 and inflammatory markers, as well as between PIEZO2 and pain markers, was verified. PIEZO2 expression was also positively correlated with pain levels. Besides, irreversible pulpitis patients who reported continuous pain and who detected a positive response to cold stimulus exhibited a higher expression level of PIEZO2 in the inflamed pulp tissues. By contrast, patients reporting pain duration of more than one week showed a higher expression level of PIEZO1. CONCLUSIONS: This study demonstrated the upregulation of PIEZO1 and the downregulation of PIEZO2 in irreversible pulpitis and revealed the potential relation of PIEZO1 and PIEZO2 to inflammation and pain. These findings suggested that PIEZOs might play critical roles in the progression of irreversible pulpitis and paved the way for further investigations aimed at novel therapies of irreversible pulpitis by targeting PIEZOs.

Upregulated Vanins and their potential contribution to periodontitis.

BACKGROUND: Although Vanins are closely related to neutrophil regulation and response to oxidative stress, and play essential roles in inflammatory diseases with clinical significance, their contribution to periodontitis remains to be determined. This research was designed to assess the expression of Vanins in human gingiva, and to define the relationship between Vanins and periodontitis. METHODS: Forty-eight patients with periodontitis and forty-two periodontal healthy individuals were enrolled for gingival tissue sample collection. Expression levels of VNN1, VNN2 and VNN3 were evaluated by RT-qPCR and validated in datasets GSE10334 and GSE16134. Western blot and immunohistochemistry identified specific proteins within gingiva. The histopathological changes in gingival sections were investigated using HE staining. Correlations between Vanins and clinical parameters, PD and CAL; between Vanins and inflammation, IL1B; and between Vanins and MPO in periodontitis were investigated by Spearman's correlation analysis respectively. Associations between VNN2 and indicators of neutrophil adherence and migration were further validated in two datasets. RESULTS: Vanins were at higher concentrations in diseased gingival tissues in both RT-qPCR and dataset analysis (p < 0.01). Assessment using western blot and immunohistochemistry presented significant upregulations of VNN1 and VNN2 in periodontitis (p < 0.05). The higher expression levels of Vanins, the larger the observed periodontal parameters PD and CAL (p < 0.05), and IL1B (p < 0.001). Moreover, positive correlations existed between VNN2 and MPO, and between VNN2 and neutrophil-related indicators. CONCLUSION: Our study demonstrated upregulation of Vanins in periodontitis and the potential contribution of VNN2 to periodontitis through neutrophils-related pathological processes.

Profiling of bile acids and activated receptor S1PR2 in gingival tissues of periodontitis patients.

BACKGROUND: Bile acids, as a group of cholesterol metabolites, play important roles in inflammation and bone metabolism. However, the possible link between bile acids and periodontitis is still unclear. This study aimed to clarify the alterations of the bile acid profile and corresponding receptor expression levels in periodontitis patients, and evaluate their association with periodontitis severity. METHODS: The concentrations of 15 bile acids in gingival tissues from 16 periodontitis patients and 16 healthy individuals were tested by metabolomics. Sphingosine-1-phosphate receptor 2 (S1PR2) expression was determined by real-time PCR and immunohistochemistry, which was also validated in two datasets, GSE16134 and GSE10334. The correlation between bile acids, S1PR2, and clinical parameters was analyzed by Spearman's correlation analysis, and receiver-operator characteristic (ROC) curves were examined to access the ability of bile acids and S1PR2 for defining local periodontitis status. RESULTS: In the periodontitis group, concentrations of total bile acids were elevated by increases of all bile acid forms, and five conjugated bile acids were significantly increased. Meanwhile, the expression of their receptor, S1PR2, was also upregulated in the periodontitis group. Positive correlations were further observed between glycocholic acid (GCA), taurochenodeoxycholic acid (TCDCA), taurocholic acid (TCA), S1PR2, and periodontal clinical parameters. ROC analysis also showed combinations of two bile acids (GCA and TCDCA) with S1PR2 as novel signatures for indicating local periodontitis status. CONCLUSION: Our findings demonstrated the alterations of the bile acid profile and receptor S1PR2 expression in periodontitis patients, and provided evidence of association between bile acids and periodontitis status.