Comparative immunohistochemical expression of Beta catenin and CD163 between dysplastic / non-dysplastic oral lichen planus and lichenoid lesions (EX-VIVO STUDY).

BACKGROUND: Oral lichen planus is a well-known chronic inflammatory mucocutaneous disorder, which has clinical and histological presentation that mimics oral lichenoid reaction. According to the fifth edition of WHO, both conditions are considered as oral potentially malignant disorders. Recent studies on oral potential disorders documented deregulation of some signaling molecules related to the Wnt/ß-catenin pathway. Therefore this study aimed to compare the immune expression of ß-catenin & CD163 in dysplastic /non-dysplastic cases of Oral lichen planus & oral lichenoid lesion. In addition, a statistical correlation between both immune markers was done regardless of the type of the study group. METHODS: Four study groups were designated as 2 groups of Oral lichen planus (one dysplastic & one non -dysplastic) and the other 2 groups were oral lichenoid lesions (one dysplastic & one non -dysplastic). Ten cases in each group were collected and investigated by immunohistochemistry. The area percent of beta catenin and also counting of m2 macrophages expressing + CD163 marker was calculated in the study groups. RESULTS: The Statistical analysis highlighted a statistically significant difference between the studied groups. Moreover, Pearson correlation test reported a significant moderate positive correlation between beta catenin & CD163 expression in the studied cases. CONCLUSION: Our findings supported new perceptions of the mechanism by which tumor associated macrophage specific ß-catenin signaling promotes the aggressive behavior of oral potential malignant disorders. CLINICAL RELEVANCE: Evidence of the relationship between beta catenin and M2 macrophages (+ CD163) may enhance the development of macrophage-based strategies for treatment and improve the prognosis of such cases.

Network pharmacology and molecular docking analysis predict the mechanisms of Huangbai liniment in treating oral lichen planus.

This study explored the mechanism of Huangbai liniment (HB) for the treatment of oral lichen planus (OLP) through network pharmacology and molecular docking techniques. The study identified HB' active ingredients, therapeutic targets for OLP, and associated signaling pathways. The chemical composition of HB was screened using the HERB database. The disease targets of OLP were obtained through the GeneCards and OMIM databases. A protein-protein interactions network was constructed with the String platform. Topological analysis was performed using Cytoscape software to identify core targets. Gene ontology and Kyoto encyclopedia of genes and genomes pathway enrichment analysis were performed using the Hiplot database, and the active ingredients and core targets were verified by molecular docking. Date analysis showed that the active composition of HB in the treatment of OLP were quercetin, wogonin, kaempferol, and luteolin. This survey identified 10 potential therapeutic targets, including TNF, CXCL8, IL-6, IL1B, PIK3R1, ESR1, JUN, AKT1, PIK3CA, and CTNNB1. Molecular docking revealed stable interactions between OLP' key targets and HB. These key targets were predominantly involved in the PI3K-Akt signaling pathway, AGE-RAGE signaling pathway, TNF signaling pathway, and HIF-1 signaling pathway. HB plays a crucial role in the treatment of OLP, acting on multiple targets and pathways, particularly the PI3K-Akt signaling pathway. It regulated biological processes like the proliferation of epithelial cells and lymphocytes and mediates the expression of transcription factors, cytokines, and chemokines. Therefore, this study provides a theoretical basis for the clinical trial and application of HB in the therapy of OLP.

Galectin-3-upregulated FAK promotes angiogenesis through oral lichen planus-activated fibroblasts.

BACKGROUND: The specific mechanism underlying the role of oral lichen planus-activated fibroblasts in angiogenesis remains undefined. Herein, the expression of Galectin-3 in oral lichen planus and verifying whether Galectin-3 can promote angiogenesis through oral lichen planus-activated fibroblasts has been investigated. METHODS: The expression of Galectin-3 and CD34 in the oral lichen planus tissues (n = 30) and normal oral mucosa tissues (n = 15) was detected by immunohistochemistry. The expression of Galectin-3 in the oral lichen planus-activated fibroblasts was determined by reverse transcription-polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assay. Galectin-3 overexpression lentiviral vector was constructed and transfected with oral lichen planus-activated fibroblasts. In addition, oral lichen planus-activated fibroblasts were treated with GB1107 (5 and 10 µM) to inhibit Galectin-3 expression and co-cultured with human umbilical vein vascular endothelial cells, and analyzed by Transwell and tube formation assays. The expression of VEGF and FGF2 in oral lichen planus-activated fibroblasts was detected, and the expression and phosphorylation levels of VEGFR2 and FAP in human umbilical vein vascular endothelial cells were determined. RESULTS: Oral lichen planus subcutaneous tissues highly expressed Galectin-3, positively correlated with angiogenesis. Oral lichen planus-activated fibroblasts expressed significantly higher Galectin-3 than NFs. Oral lichen planus-activated fibroblasts overexpressing Galectin-3 enhanced the migration and tube-forming capacity of co-cultured human umbilical vein vascular endothelial cells. In oral lichen planus-activated fibroblasts, 10 µM GB1107 reduced the proliferation and migration capacity, decreased the expression of α-SMA, FAP, VEGF, and FGF2, and inhibited the tube-forming capacity and the expression of VEGFR2 phosphorylation and FAK in co-cultured human umbilical vein vascular endothelial cells. CONCLUSIONS: The upregulation of Galectin-3 expression in oral lichen planus is associated with angiogenesis, and the oral lichen planus-activated fibroblasts promote human umbilical vein vascular endothelial cells migration and tube-forming differentiation through VEGFR2/FAP activation by Galectin-3.

A critical influence of HIF-1 on MMP-9 and Galectin-3 in oral lichen planus.

OBJECTIVE: Oral lichen planus carries a risk for malignancy. The pathogenesis of the disease is mediated by various inflammatory mediators. Several mediators could be responsible for the oncogenic behavior in certain cases. Hypoxia-inducible factor-1a (HIF-1), and its possible correlation to Galactin-3 (Gal-3) and matrix metalloproteinase-9 (MMP-9) over expression represents an important indicator for malignant transformation. The investigation of these factors may present evidence-based information on malignant transformation of the disease. SUBJECTS AND METHODS: The study investigated the expression of HIF-1, Gla-3 and MMP-9 in tissue samples of OLP compared to control subjects of un-inflamed gingival overgrowth. 20 biospecimen were allocated in each group. RESULTS: Immunohistochemical findings of OLP showed immunoreactivity for Galectin 3, HIF1a and MMP-9 by most of the epithelial cells. There was a positive correlation between HIF1α and MMP-9, r = 0.9301 (P-value < 0.00001). A positive correlation was detected between Galectin 3 and MMP-9, r = 0.7292 (P-value = 0.000264) between Galectin 3 and HIF1α, r = 0.5893 (P-value = 0.006252). CONCLUSION: These findings confirm the hypothesis that the adaptive pathways to hypoxia as Gal 3 and MMP-9 expressions and their HIF-1 may play a crucial role in carcinogenesis of OLP.

The role of vitamin D in amelioration of oral lichen planus and its effect on salivary and tissue IFN-γ level: a randomized clinical trial.

BACKGROUND AND OBJECTIVES: Oral lichen planus (OLP) is a common, prevalent, immune-mediated, inflammatory disease affecting both the skin and oral mucosa and is considered one of the potentially malignant diseases. Since OLP is regarded as an immunologically mediated disease, some studies suggest the use of vitamin D (VD) for its management as it exhibits immune-modulatory, anti-inflammatory, and antimicrobial properties, as well as anti-proliferative, pro-differentiative, and anti-angiogenic effects. VD has demonstrated a suppressive effect on TH1 pro-inflammatory cytokines, including IFN-γ while augmenting the secretion of anti-inflammatory cytokines. At the same time, VD deficiency is a prevalent public issue. Therefore, the present study aimed to investigate the role of VD as an adjunct to steroids in the management of VD-deficient OLP patients as well as its inhibitory effect on IFN-γ through measurement of salivary and tissue IFN-γ levels in OLP patients. METHODS: A total of 40 patients with ulcerative or erythematous OLP, diagnosed according to the World Health Organization's (WHO) modified criteria for OLP, were randomly allocated into one of the two study groups to receive either systemic steroids in addition to VD supplements (Group A) or systemic steroids only (Group B). Blood samples were collected for the measurement of serum VD level (SVDL) using the enzyme-linked immunosorbent assay (ELISA) to involve only patients with VD deficiency or insufficiency (≤ 30 ng/ml). Clinical evaluation of the lesion involved objective signs and subjective symptoms. Also, changes in salivary and tissue INF-γ levels (in pg/mL and pg/mg, respectively) were determined using the ELISA technique. All parameters were measured at baseline and after 4 weeks of treatment. The clinical pharmacy team devised a checklist to record all team interventions. The interventions were categorized into six domains, including drug interactions and/or adverse reactions, medication dose issues, drug selection issues, support with medication history, patient-related concerns, and suggestions for dental medication. RESULTS: After one month of treatment, a significantly greater number of patients in group A showed complete pain relief and resolution of clinical lesions, as well as a greater number of patients showing a reduction in the clinical severity of lesions than in group B (P = 0.005). Also, there was a statistically significant reduction in average VAS pain scores and clinical scores in group A compared to group B after 1 month of treatment (P = 0.001 and 0.002, respectively). Furthermore, there was a statistically significant greater reduction in salivary and tissue IFN-γ levels in group A than in group B (P ≤ 0.001 and 0.029, respectively) after 1 month of treatment. CONCLUSION: Current evidence suggests a significant preventive and therapeutic role for VD as an adjunct to standard therapies indicated for OLP lesions. These protective and therapeutic functions are achieved through the suppressive effect of VD on pro-inflammatory cytokines, particularly IFN-γ. Also, salivary IFN-γ appears to be a valuable prognostic marker for monitoring the progression of OLP. In addition, the inter-professional collaboration between dentists and clinical pharmacists helped to deliver complete, patient-centered primary care and ensured the quality of the medications included in patient kits, thus improving patient treatment and management. Nevertheless, further studies with larger sample sizes, longer follow-ups, and standardized designs may still be needed.

Salivary Histamine Levels in Patients with Oral Lichen Planus Lesions.

Background and Objectives: An oral lichen planus (OLP) chronic lesion refers to a group of oral potentially malignant disorders (OPMDs) that still lack a proper understanding from the point of view of relevant biomarkers for diagnostics and prognosis. The aim of the study was to assess the salivary histamine levels in patients with oral lichen planus lesions. Materials and Methods: The study included a group of 76 patients with oral lichen planus. General diseases and medication taken, smoking habits, severity of pain assessed using a visual analogue scale (VAS), oral hygiene status, and duration of OLP were evaluated. ELISA diagnostics for histamines in saliva levels were assessed. Results: The histamine levels in the OLP group were higher (0.468) in comparison with the control group (0.056), without a statistically significant value p = 0.090 (Mann-Whitney U Test). The median age of 76 OLP patients was 63 years (min 22.0-max. 81), with the biological sex being 80.3% females and 15 19.7% males. The average duration of OLP lesion presence was 29.4 months (SD 37.1) and the median value was 14.5 months. The median of the VAS was 3.0. OLP assessment in accordance with the Malhotra methodology showed the highest frequency-30.3% for only two of the point areas involved and 17.1% for three points. Clinical assessment of the different OLP grades, severity, and oral site involvement and the VAS in correlation with histamine salivary levels showed a lack of statistical significance in the investigated population. Conclusions: Undertaking further research could provide further possibilities for searching for general factors in OLP development.

Function of unconventional T cells in oral lichen planus revealed by single-cell RNA sequencing.

OBJECTIVE: We intended to map the single-cell profile of OLP, explore the molecular characteristics of unconventional T cells in OLP tissues. METHODS: Buccal mucosa samples from OLP patients and healthy individuals were used to prepare single-cell suspension. Single-cell RNA sequencing was used to analyze the proportion of all the cells, and the molecular characteristics of unconventional T cells. Immunohistochemical staining was used to detect the expression of unconventional T cells marker genes. RESULTS: The cell clusters from buccal mucosa were categorized into immune cells, fibroblasts, endothelial cells, and epithelial cells. Unconventional T cells with phenotype of CD247+TRDC+NCAM1+ were identified. Immunohistochemical staining revealed higher expression of unconventional T cell marker genes in OLP tissue, predominantly in the lamina propria. In OLP, unconventional T cells are in a unique stress response state, exhibited enhanced NF-κB signaling and apoptosis inhibition, enhanced heat shock protein genes expression, weakened cytotoxic function. A large number of ligand-receptor pairs were found between unconventional T cells and other cells, particularly with fibroblasts and endothelial cells. CONCLUSIONS: This study mapped the single-cell profile of OLP, delineated the molecular characteristics of unconventional T cells in OLP, and uncovered that these unconventional T cells are in a stress response state.

Is Salivary Α-Amylase a Reliable Indicator of Psychological Status and Quality of Life in Patients with Oral Lichen Planus: a Case-Control Study.

BACKGROUND/AIMS: The objectives of our study were to determine salivary α-amylase activity (stress biomarker) and its association with psychological status and quality of life (QoL), disease duration and intensity of symptoms (pain/burning) in patients with OLP. METHODS: A total of 50 subjects participated in this case-control study: 30 patients with oral lichen planus (OLP); 20 control subjects. Unstimulated whole saliva (UWS) was collected between 9 and 10 am to avoid diurnal fluctuations. Psychological status was assessed using the Croatian validated version of the original Depression, Anxiety and Stress Scale (DASS-21). The impact of oral health on QoL was assessed using the Croatian version of the Oral Health Impact Profile Questionnaire (OHIP-CRO14). RESULTS: There was no statistically significant difference in salivary α-amylase activity between patients with OLP (N=30) and control subjects (N=20) (133813.3 vs. 166815.5 U/L, p=0.314; t-test). Depression, anxiety and stress showed no statistically significant difference between patients with OLP and control subjects (p=0.076, p=0.111, p=0.209; t-test). The patients with OLP had statistically significantly poorer QoL (total) compared to control subjects (p=0.004, t-test). There was a moderate positive correlation between symptom intensity (pain/burning) and poor QoL (total) (r=0.584, p<0.001), the OHIP-CRO14 dimension "physical pain" (r=0.661, p<0.001), "psychological impossibility" (r=0.555, p<0.01), "handicap" (r=0.546, p<0.01). CONCLUSION: Although salivary α-amylase showed no statistically significant difference between patients with OLP and control subjects, the patients with OLP had poorer psychological status (three times higher scores for depression and two times higher scores for anxiety) and poorer QoL compared to the control subjects. Recognising and treating mental disorders in patients with OLP is important in order to break the "vicious circle" and achieve a better QoL in these patients.

CD4+CD8αα+ is the dominant phenotype of intraepithelial lymphocytes and regulated by ThPOK and Runx3 in oral lichen planus.

BACKGROUND: Oral lichen planus (OLP) is a common T cell-mediated oral mucosal immune inflammatory disease. Intraepithelial lymphocytes (IELs) are a unique subset of T cells that play an important role in regulating immune response. This study aims to investigate the phenotype and the differentiation mechanism of IELs in OLP. METHODS: The expression of CD4, CD8α, CD8ß, T-helper-inducing POZ/Krueppel-like factor (ThPOK), and RUNX family transcription factor 3 (Runx3) in the epithelium and peripheral blood mononuclear cells (PBMCs) of OLP was determined by immunofluorescence and immunohistochemistry. Then, the correlations among them were analyzed. Naïve CD4+ T cells were sorted from blood of OLP patients and stimulated with retinoic acid (RA) and transforming growth factor-ß1 (TGF-ß1). Then the expression of CD4, CD8α, CD8ß, ThPOK, and Runx3 was investigated by immunocytochemistry. RESULTS: CD8α expression and CD8αα+ cells were upregulated in the epithelium of OLP, whereas they were downregulated in PBMCs of OLP. CD8ß was not expressed in the epithelium of OLP. CD4, CD8α, and Runx3 expression and CD4+CD8α+ cells were increased, whereas ThPOK expression was decreased in the epithelium of OLP. CD8α expression was positively correlated with Runx3 expression, whereas ThPOK expression was negatively correlated with Runx3 expression. After RA and TGF-ß1 stimulation, CD8α and Runx3 expression was upregulated, and ThPOK expression was downregulated in naïve CD4+ T cells. CONCLUSION: CD4+CD8αα+ IELs may be the dominant phenotype of IELs in OLP, and the differentiation of CD4+CD8αα+ IELs in OLP is negatively regulated by ThPOK and positively regulated by Runx3.

Expression of epithelial growth factor receptor as a protein marker in oral reticular and erosive lichen planus.

BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory mucosal disease that is classified as a premalignant condition. Epithelial growth factor receptor (EGFR) is associated with tumorigenesis and tumor progression and is overexpressed in several oral malignant disorders. Despite the association of EGFR overexpression with oral potentially malignant lesions, few studies have analyzed its expression in OLP, showing controversial results. This study aimed to compare the expression of EGFR as a protein marker in Reticular and Erosive OLP. METHODS: This descriptive-analytical cross-sectional was conducted on 15 paraffin blocks of reticular lichen planus lesions, 16 paraffin blocks of erosive OLP lesions, and 8 paraffin blocks of inflammatory fibrous hyperplasia lesions as the control group (39 in total). After immunohistochemical staining for EGFR, samples were simultaneously observed by two maxillofacial pathologist, and the percentage of stained cells, intensity of staining, pattern of staining, and the location of stained cells were obtained. RESULTS: The Mann-Whitney-U test showed that there was no significant difference in the mean percentage of stained cells between erosive OLP and reticular OLP (P-value = 0.213) and between reticular OLP and control group (P-value = 0.137), but there was a significant difference between erosive OLP and control group (P-value = 0.035). Fisher's exact test showed that there was no significant difference between the frequency distribution of staining patterns in three types of lesions (P-value = 0.90). Kruskal-Wallis test showed that there was no significant difference between the intensity of staining in the three groups (P-value = 0.19) and also there was no significant difference between the location of stained cells in different layers of the epithelium in the three groups (P-value = 0.90). CONCLUSIONS: The results of this study showed that in comparison of reticular OLP, erosive OLP, and the control group there was a significant difference just between erosive OLP and control group in the percentage of stained cells.

Upregulation of psoriasin/S100A7 correlates with clinical severity in patients with oral lichen planus.

OBJECTIVES: The aim of this study was to: (1) investigate the expression patterns of antimicrobial peptides (AMPs), specifically psoriasin (S100A7) and calgranulin A and B (S100A8/A9), in patients with oral lichen planus (OLP) compared to healthy individuals; (2) evaluate the oral health-related quality of life (OHrQoL) in OLP patients versus healthy controls; (3) investigate the impact of clinical severity of OLP on OHrQoL; and (4) assess the influence of AMP expression on clinical severity and OHrQoL in OLP patients. MATERIALS AND METHODS: Oral mucosal biopsies (n = 38) were collected from healthy individuals (n = 17) and patients with OLP (n = 21). Levels of AMPs (S100A7, S100A8, S100A9) and pro-inflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor alpha (TNFα) were assessed by RT-qPCR. AMP protein localization was identified by indirect immunofluorescence analysis. OHrQoL was assessed using the OHIP-G14 questionnaire, and clinical severity was evaluated with the Oral Disease Severity Score (ODSS). Correlations between OLP manifestation, OHrQoL, and AMP expression were evaluated. RESULTS: (1) S100A7 (p < 0.001), IL-8 (p < 0.001), and TNFα (p < 0.001) mRNA levels were significantly upregulated in OLP tissue compared to healthy tissue, while S100A8 (p < 0.001) and S100A9 (p < 0.001) mRNA levels were downregulated. Immunofluorescence staining revealed an enhanced expression of S100A7 and decreased protein expression of S100A9 in OLP tissue. (2) OLP patients (9.58 ± 8.32) reported significantly higher OHIP-G14 scores compared to healthy individuals (0.67 ± 0.87; p < 0.001), particularly in the categories "physical pain" (p < 0.001) and "psychological discomfort" (p = 0.025). (3,4) Clinical severity (25.21 ± 9.77) of OLP correlated positively with OHrQoL (ρ = 0.497) and psoriasin expression (ρ = 0.402). CONCLUSIONS: This study demonstrated differential expression patterns of AMPs in OLP and highlighted the correlation between the clinical manifestation of OLP and OHrQoL. Further research approaches should address the role of psoriasin in the risk of malignant transformation of OLP. CLINICAL RELEVANCE: Psoriasin is a putative biomarker to monitor disease severity including malignant transformation of OLP lesions. OHIP-G14 scores can be useful to monitor OHrQoL in OLP patients.

Dysregulation of TCONS_00006091 contributes to the elevated risk of oral squamous cell carcinoma by upregulating SNAI1, IRS and HMGA2.

In this study, we aimed to study the role of TCONS_00006091 in the pathogenesis of oral squamous cellular carcinoma (OSCC) transformed from oral lichen planus (OLP). This study recruited 108 OSCC patients which transformed from OLP as the OSCC group and 102 OLP patients with no sign of OSCC as the Control group. ROC curves were plotted to measure the diagnostic values of TCONS_00006091, miR-153, miR-370 and let-7g, and the changes in gene expressions were measured by RT-qPCR. Sequence analysis and luciferase assays were performed to analyze the molecular relationships among these genes. Cell proliferation and apoptosis were observed via MTT and FCM. TCONS_00006091 exhibited a better diagnosis value for OSCC transformed from OLP. OSCC group showed increased TCONS_00006091 expression and decreased expressions of miR-153, miR-370 and let-7g. The levels of SNAI1, IRS and HMGA2 was all significantly increased in OSCC patients. And TCONS_00006091 was found to sponge miR-153, miR-370 and let-7g, while these miRNAs were respectively found to targe SNAI1, IRS and HMGA2. The elevated TCONS_00006091 suppressed the expressions of miR-153, miR-370 and let-7g, leading to the increased expression of SNAI1, IRS and HMGA2. Also, promoted cell proliferation and suppressed apoptosis were observed upon the over-expression of TCONS_00006091. This study demonstrated that the expressions of miR-153, miR-370 and let-7g were down-regulated by the highly expressed TCONS_00006091 in OSCC patients, which accordingly up-regulated the expressions of SNAI1, IRS and HMGA2, resulting in the promoted cell proliferation and suppressed cell apoptosis.

[Detection of molecular affecting sensitivity to local glucocorticoid therapy in oral lichen planus through transcriptome sequencing].

OBJECTIVE: To detect key genes of local glucocorticoid therapy in oral lichen planus (OLP) through transcriptome sequencing. METHODS: The study prospectively enrolled 28 symptomatic patients who visitied Department of Oral Mucosa, Peking University Hospital of Stomatology from November 2019 to March 2023. Topical inunction of 0.1 g/L of dexamethasone was applied for 1 min, 3 times daily for 4 weeks. The patients' signs and pain symptoms were recorded and they were classified as effective group and ineffective group according to the treatment outcome. Their mucosa samples were collected before treatment. After isolating total RNA, transcriptome sequencing was performed. The gene expression data obtained by sequencing were analyzed differently using the DESeq2 package in R software, and the Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis was performed on the basis of the hypergeometric distribution algorithm to describe the biological function of differentially expressed genes (DEGs), accordingly detecting sensitivity related molecular affecting therapeutic effect of dexamethasone. RESULTS: After 4 weeks treatment by topical dexamethasone, 13 cases of the 28 OLP patients responding well with the sign score reducing from 7.0 (4.5, 9.0) to 5.0 (3.0, 6.3), pain score decreasing from 5.0 (2.0, 5.5) to 2.0 (0.0, 3.5), oral health impact profile lessening from 5.0 (3.5, 9.0) to 1.0 (0.0, 5.0) significantly (P<0.01) were classified as effective group and 15 cases with poor response to the drug were sorted as ineffective group. There were no significant differences of demographic and baseline levels of clinical features, especially disease severity between these two groups. A total of 499 DEGs including 274 upregulated and 225 downregulated genes were identified between effective group and ineffective group. KEGG enrichment analysis showed that upregulated genes in effective group compared with ineffective group including CLDN8, CTNNA3, MYL2 and MYLPF were associated with leukocyte transendothelial migration, while downregulated genes were significantly enriched in tumor necrosis factor (TNF), interleukin-17 (IL-17), nuclear factor kappa B (NF-κB) signaling pathways, and cortisol synthesis and secretory. CONCLUSION: High expressions of CLDN8, CTNNA3, MYL2 and MYLPF genes in patients with oral lichen planus have a good clinical response to topical dexamethasone, while patients with high expression genes of inflammation pathway such as TNF, IL-17, NF-κB and cortisol synthesis and secretion received poor effect.

MALT1 Protease Regulates T-Cell Immunity via the mTOR Pathway in Oral Lichen Planus.

Oral lichen planus (OLP) is a T cell-mediated immune mucosal disease of unknown pathogenesis. Whether mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), an intracellular signaling protein, is involved in the T-cell immune dysfunction of OLP remains elusive. MALT1 expression in local and peripheral T cells of OLP and controls was analyzed using immunohistochemistry, multiplex immunohistochemistry, and flow cytometry. The expression of MALT1 in activated Jurkat T cells incubated with either OLP plasma or interleukin (IL)-7/IL-15 was determined by flow cytometry. The effects of MALT1 and mechanistic target of rapamycin (mTOR) on T-cell immunity were investigated through western blot, CCK8 assay, and flow cytometry. The expression of MALT1 protein was elevated in local OLP T cells and mucosal-associated invariant T (MAIT) cells, while reduced in peripheral OLP T cells, MAIT cells, and follicular helper-like MAIT (MAITfh) cells. Stimulation with OLP plasma and IL-7/ IL-15 had no effect on MALT1 expression in activated Jurkat T cells. MALT1 protease-specific inhibitor (MI-2) induced mTOR phosphorylation, increased B-cell lymphoma 10 (BCL10) expression, inhibited T-cell proliferation, and promoted T-cell apoptosis. The combination of MI-2 and rapamycin increased MALT1 expression, further suppressed T-cell proliferation, and facilitated T-cell apoptosis. MALT1 expression is aberrant in both local lesions and peripheral blood of OLP. Inhibition of the mTOR pathway further enhances the suppression of T-cell proliferation and the promotion of apoptosis induced by the MALT1 inhibitor MI-2.

The expression of p53, ki67 and COX-2 in erosive-type oral lichen planus.

Oral lichen planus is a chronic inflammatory disease that affects the oral mucosa and may undergo malignant changes, which can be reflected in the expression of specific proteins that are responsible for maintaining cellular mitosis and apoptosis. The study aimed to investigate the expression of p53, ki67, and COX-2 in erosive lichen planus using immunohistochemistry to correlate these findings with the histological aspects of the disease. Thirty-three biopsies of erosive lichen planus were collected and diagnosed based on histological and clinical criteria. The blocks were processed for immunohistochemistry to assess p53, ki67, and COX-2 expression in the basal layer, suprabasal, and inflammatory infiltrate respectively. The histological analysis of the samples showed no dysplasia or metastasis. P53 stained positively in 80% of the samples, while ki67 was positive in all the cases, ranging from 5% to 85% positivity. COX-2 expression ranged from 0-50% positivity. The highest expression of p53 was observed in 8 cases (24.2%), with a maximum of 5%, and ki67 exhibited the highest expression of 90% in 3 cases (9.1%). COX-2 was negative in 27 cases (81.8%) and positive in 6 cases (18.1%), with the highest expression at 50% in 1 case and 10 % positivity in 4 cases (12.1%). In our study, the markers p53, ki67, and COX-2 proved to be useful for detecting the proliferative, inflammatory, and physiologic states of the keratinocytes. However, they did not demonstrate utility in detecting any malignant transformation.

Patients with oral lichen planus display lower levels of salivary acidic glycoproteins than individuals without oral mucosal disease.

OBJECTIVES: Salivary proteins, acidic glycoproteins, and free calcium might take part in oral mucosal defence against inflammation in oral lichen planus (OLP). The study aimed to investigate whether the levels of sulfated and sialylated glycoproteins, total protein, and free calcium in saliva from patients with OLP differ from those of individuals without oral mucosal diseases. MATERIAL AND METHODS: Patients diagnosed with OLP (n = 25) and two control groups without any oral mucosal disease; age- and gender-matched controls (n = 25, 65.6 ± 2.9 years), and younger controls (n = 25, 41.8 ± 2.5 years) were included. Subjective dry mouth (xerostomia) was assessed by asking a single-item question. Chew-stimulated whole saliva was collected to measure sulfated and sialylated glycoproteins by the Alcian Blue method. The total protein was determined spectrophotometrically, and the free calcium measured using an electrode. RESULTS: The output of salivary sulfated and sialylated glycoproteins in the OLP group (21.8 ± 2.4 µg/min) was lower than in the age- and gender-matched controls (43.0 ± 2.9 µg/min, p = 0.0002), whereas the total protein and calcium output did not differ between the three groups (p > 0.05). The prevalence of xerostomia was significantly higher in the OLP group compared to both control groups (p = 0.038). CONCLUSIONS: Patients with OLP showed a high prevalence of xerostomia and lower levels of salivary acidic type glycoproteins compared to the individuals without oral mucosa disease. CLINICAL RELEVANCE: It is relevant to investigate the role of acidic glycoproteins in the pathogenesis of OLP.

The expression of Th17/Treg in oral submucosal fibrosis carcinogenesis and the significance in the development of mucosal lesions.

It targets to explore the expression of Th17/Treg in oral submucous fibrosis (OSF) carcinogenesis and its significance in the development of mucosal lesions. In this research, 100 patients with OSF who visited our hospital for surgical treatment from March 2020 to April 2022 were selected. Based on pathological examination results, the patients were divided into 27 patients with oral leukoplakia (OK) group, 14 patients with oral lichen planus (OLP) group, 9 patients with oral squamous cell carcinoma (OSCC) group, and 50 patients with OSF group. It adopted flow cytometry (FC) to calculate the ratio of peripheral blood Th17 cells and Treg cells in four groups, and the Th17/Treg ratio was calculated; The area of oral mucosal lesions (OML) from patients was collected. It needs to compare the differences in Th17/Treg ratio and OML area among four groups and determine the correlation between indicators. ROC curve was used to analyze the diagnostic threshold of the Th17/Treg ratio for carcinogenesis. Except for the OK and OLP, it had statistical significance differences in Th17, Treg cells, and Th17/Treg ratio (P<0.001); The area of OML in the OK, OLP, and OSCC was higher than that in the simple OSF, with statistical significance (P<0.001); Th17 (%), Treg (%), and Th17/Treg all had direct ratio with the area of OML; The area of OML has directed ratio with the development of mucosal lesions (r>0, P<0.05); The areas under the ROC curve for patients with OSF combined with OK, OLP, or OSCC with Th17 (%), Treg (%), Th17/Treg, and OML area were 0.560, 0.986, 0.936, and 0.466, respectively. The expression of Th17/Treg is elevated in oral submucosal fibrosis and carcinogenesis. When mucosal lesions progress or become cancerous, the Th17/Treg ratio increases accordingly, and it has more clinical value than the increase in the OML area.

Immunohistochemical expression of T-cell subsets (CD4 and CD8) in oral lichen planus.

Introduction: oral lichen planus (OLP) is a common oral mucosal disease with various clinical manifestations. The most predominant types are reticular and erosive. Despite extensive research on the causes of OLP, the exact etiology remains unclear. However, it is believed that a T-cell-mediated response, which triggers the apoptosis of oral epithelial cells, may contribute to the development of this disorder. This study aims to investigate the different types of T-cells (specifically CD4 and CD8) present in OLP tissue samples. By using immunohistochemistry, the expressions of cluster of differentiation 4 (CD4) and cluster of differentiation 8 (CD8) will be evaluated in biopsy samples taken from OLP patients who exhibit various clinical presentations. Methods: this study was a retrospective analysis study. Oral lichen planus was established histologically in forty paraffin-embedded tissue samples. Blocks of OLP were diagnosed and characterized as reticular or erosive. Immunohistochemical staining was conducted using a monoclonal antibody for (CD4) and a polyclonal antibody for CD8. Semi-quantitative techniques were used to analyze the patterns of positively stained cells. Results: forty biopsies of OLP cases were obtained from 24 females and 16 males. The mean age was (49.15±11.39) years. Using an immunohistochemical method, the proportion of CD4 expression: CD8 expression among the epithelial-connective tissue interface was shown to be 24 (60%) cases with a predominance of CD8, 9 (22.5%) cases with no difference, and only 7 (17.5%) cases with a predominance of CD4. The proportion of CD4: CD8 among perivascular parts was shown to be 8 (20%) cases with a predominance of CD8, 20 (50%) cases with no difference, while only 12 (30%) cases had a predominance of CD4. The CD4 perivascular expression was significantly stronger in (71.4%) of erosive OLP than in reticular cases. Conclusion: T-cell subsets (CD4 and CD8) were found in the OLP infiltrates. The correlation may have contributed to the pathogenesis of OLP.

METTL14-upregulated miR-6858 triggers cell apoptosis in keratinocytes of oral lichen planus through decreasing GSDMC.

Oral lichen planus (OLP), a chronic inflammatory disorder, is characterized by the massive cell apoptosis in the keratinocytes of oral mucosa. However, the mechanism responsible for triggering oral keratinocyte apoptosis is not fully explained. Here, we identify that Gasdermin C (GSDMC) downregulation contributes to apoptosis in human oral keratinocytes. Mechanistically, we describe that activated nuclear factor kappa B (NF-κB) pathway induces overexpression of methyltransferase-like 14 (METTL14), which increases N6-adenosine methylation (m6A) levels in the epithelial layer of OLP. m6A modification is capable of regulating primary miR-6858 processing and alternative splicing, leading to miR-6858 increases. miR-6858 can bind and promote GSDMC mRNA degradation. Forced expression of GSDMC is able to rescue cell apoptosis in human oral keratinocyte models resembling OLP. Collectively, our data unveil that m6A modification regulates miR-6858 production to decrease GSDMC expression and to trigger keratinocyte apoptosis in the context of OLP.

Upregulation of IL-37 in epithelial cells: A potential new mechanism of T cell inhibition induced by tacrolimus.

Oral lichen planus (OLP) is a chronic T cell-mediated mucocutaneous disease characterized by T cell infiltration at the connective tissue-epithelium interface. Traditionally, topical corticosteroids are used as the first-line drugs to treat OLP. However, long-term use of corticosteroids may lead to drug tolerance, secondary candidiasis, and autoimmune adrenal insufficiency. Although topical tacrolimus has often been recommended for short-term use in corticosteroid-refractory OLP, the precise role of tacrolimus in epithelial cells remains elusive. This study showed that tacrolimus could directly upregulate the expression of IL-37 in human gingival epithelial cells by promoting the TGF-ßRI/Smad3 pathway independently of calcineurin inhibition and MAPKs. In contrast, dexamethasone, one of the corticosteroids, did not have the same effect. Moreover, IL-37 could inhibit the proliferation of activated T cells and the secretion of effector cytokines and alleviate epithelial cell apoptosis and death caused by activated T cells ina co-culturesystem. Furthermore, compared with healthy controls, IL-37 and p-Smad3 levels significantly increased in the oral mucosa affected by OLP, especially in the epithelium. IL-37 might have mediated a negative feedback mechanism to curb excessive inflammation in OLP. However, the expression of IL-37 was not associated with the infiltration of CD8+ T cells and Tregs in OLP, implying that IL-37 might mostly affect T cell activation rather than T cell differentiation and migration. Overall, this study discovered a potential novel mechanism by which tacrolimus might indirectly inhibit T cell-mediated immune damage by upregulating IL-37 in human gingival epithelial cells.