DPSCs regulate epithelial-T cell interactions in oral submucous fibrosis.

BACKGROUND: Oral submucous fibrosis (OSF) is a precancerous lesion characterized by fibrous tissue deposition, the incidence of which correlates positively with the frequency of betel nut chewing. Prolonged betel nut chewing can damage the integrity of the oral mucosal epithelium, leading to chronic inflammation and local immunological derangement. However, currently, the underlying cellular events driving fibrogenesis and dysfunction are incompletely understood, such that OSF has few treatment options with limited therapeutic effectiveness. Dental pulp stem cells (DPSCs) have been recognized for their anti-inflammatory and anti-fibrosis capabilities, making them promising candidates to treat a range of immune, inflammatory, and fibrotic diseases. However, the application of DPSCs in OSF is inconclusive. Therefore, this study aimed to explore the pathogenic mechanism of OSF and, based on this, to explore new treatment options. METHODS: A human cell atlas of oral mucosal tissues was compiled using single-cell RNA sequencing to delve into the underlying mechanisms. Epithelial cells were reclustered to observe the heterogeneity of OSF epithelial cells and their communication with immune cells. The results were validated in vitro, in clinicopathological sections, and in animal models. In vivo, the therapeutic effect and mechanism of DPSCs were characterized by histological staining, immunohistochemical staining, scanning electron microscopy, and atomic force microscopy. RESULTS: A unique epithelial cell population, Epi1.2, with proinflammatory and profibrotic functions, was predominantly found in OSF. Epi1.2 cells also induced the fibrotic process in fibroblasts by interacting with T cells through receptor-ligand crosstalk between macrophage migration inhibitory factor (MIF)-CD74 and C-X-C motif chemokine receptor 4 (CXCR4). Furthermore, we developed OSF animal models and simulated the clinical local injection process in the rat buccal mucosa using DPSCs to assess their therapeutic impact and mechanism. In the OSF rat model, DPSCs demonstrated superior therapeutic effects compared with the positive control (glucocorticoids), including reducing collagen deposition and promoting blood vessel regeneration. DPSCs mediated immune homeostasis primarily by regulating the numbers of KRT19 + MIF + epithelial cells and via epithelial-stromal crosstalk. CONCLUSIONS: Given the current ambiguity surrounding the cause of OSF and the limited treatment options available, our study reveals that epithelial cells and their crosstalk with T cells play an important role in the mechanism of OSF and suggests the therapeutic promise of DPSCs.

Salivary and serum levels of lactate dehydrogenase in oral submucous fibrosis: A meta-analysis.

BACKGROUND: The occurrence of oral submucous fibrosis (OSF) is often accompanied by an increase in lactate dehydrogenase (LDH) levels. In this meta-analysis, we compared the salivary and serum levels of LDH levels between OSF patients and controls. MATERIAL AND METHODS: A comprehensive search was conducted in PubMed, Embase, Web of Science, and Cochrane Library from the establishment of the database to June 2023, and the quality of the studies was checked by the Newcastle-Ottawa Quality Assessment scale. The mean difference (MD) and 95% confidence interval (CI) were calculated using RevMan 5.4 software. RESULTS: A total of 28 studies were retrieved from the database, and we included 5 studies in this meta-analysis. The salivary LDH level of OSF patients was higher than healthy controls (MD: 423.10 pg/L 95%CI: 276.42-569.77 pg/mL, P < .00001), the serum LDH level of OSF patients was also higher than that of healthy controls (MD: 226.20 pg/mL, 95%CI: 147.71-304.69 pg/mL, P < .00001). CONCLUSIONS: This meta-analysis showed that salivary and serum LDH levels were higher in OSF patients than in healthy controls, suggesting that LDH may be a potential biomarker for OSF.

Expression Profile of Circulating Exosomal microRNAs in Leukoplakia, Oral Submucous Fibrosis, and Combined Lesions of Leukoplakia and Oral Submucous Fibrosis.

OBJECTIVES: This study aims to elucidate the expression of circulating exosomal miRNAs miRNA 21, miRNA 184, and miRNA 145 in the studied groups, including patients with (i) leukoplakia; (ii) oral submucous fibrosis; (iii) oral submucous fibrosis with leukoplakia; (iv) oral squamous cell carcinoma; and (v) healthy individuals. STUDY DESIGN: An observational study was conducted among 54 patients who reported to the outpatient department of Saveetha Dental College and Hospitals. The patients were divided into three groups: Group I healthy individuals (n = 18), Group II: case group (leukoplakia, OSMF, and leukoplakia and OSMF) (n = 18), and Group III: OSCC (n = 18). Real-time polymerase chain reaction analysis was carried out to assess the expression profiles of miRNA 21, miRNA 184, and miRNA 145. The statistical analysis was calculated using SPSS software version 23. RESULTS: All three miRNAs showed a statistically significant difference in the one-way ANOVA test between the case group (leukoplakia, OSMF, and leukoplakia and OSMF), healthy group, and OSCC group (p < 0.005). The case group (leukoplakia, OSMF, leukoplakia and OSMF) showed upregulated expression of miRNA 21 and miRNA 184 with threefold change and fourfold change and downregulated expression of miRNA 145 with 1.5-fold change when compared to apparently healthy individuals. CONCLUSION: Plasma circulating exosomal miRNAs miRNA 21, miRNA 145, and miRNA 184 expression could be a novel panel of plasma biomarkers to categorise case group (leukoplakia, OSMF, leukoplakia and OSMF) patients with a high risk of malignant transformation.

Aberrantly downregulated FENDRR by arecoline elevates ROS and myofibroblast activation via mitigating the miR-214/MFN2 axis.

Long non-coding RNA FENDRR possesses both anti-fibrotic and anti-cancer properties, but its significance in the development of premalignant oral submucous fibrosis (OSF) remains unclear. Here, we showed that FENDRR was downregulated in OSF specimens and fibrotic buccal mucosal fibroblasts (fBMFs), and overexpression of FENDRR mitigated various myofibroblasts hallmarks, and vice versa. In the course of investigating the mechanism underlying the implication of FENDRR in myofibroblast transdifferentiation, we found that FENDRR can directly bind to miR-214 and exhibit its suppressive effect on myofibroblast activation via titrating miR-214. Moreover, we showed that mitofusin 2 (MFN2), a protein that is crucial to the fusion of mitochondria, was a direct target of miR-214. Our data suggested that FENDRR was positively correlated with MFN2 and MFN2 was required for the inhibitory property of FENDRR pertaining to myofibroblast phenotypes. Additionally, our results showed that the FENDRR/miR-214 axis participated in the arecoline-induced reactive oxygen species (ROS) accumulation and myofibroblast transdifferentiation. Building on these results, we concluded that the aberrant downregulation of FENDRR in OSF may be associated with chronic exposure to arecoline, leading to upregulation of ROS and myofibroblast activation via the miR-214-mediated suppression of MFN2.

Change and pathological significance of glycogen content in oral squamous cell carcinoma and oral submucous fibrosis.

OBJECTIVE: This study aimed to investigate the change and pathological significance of glycogen content in oral squamous cell carcinoma (OSCC) and oral submucous fibrosis (OSF). METHODS AND MATERIALS: 13 normal oral mucosa (NOM), 12 OSF mucosa, and 35 pairs of OSCC tissues and their corresponding adjacent mucosa tissues (AT) were collected from Xiangya Hospital for PAS staining to detect glycogen. Transcriptome sequencing data from OSCC were used to compare glycogen metabolism gene expression differences. Kaplan-Meier method was conducted to estimate Recurrence-free survival (RFS). RESULTS: Glycogen levels were lower in OSF than in NOM and lower in OSCC than in AT. Transcriptome sequencing data analysis showed the expression of most glycogenolysis genes was increased and the expression of glycogen synthesis genes including PPP1R3C and GBE1 was decreased in OSCC tissues. High glycogen level was correlated with poor prognosis in OSCC patients under the background of OSF. CONCLUSION: Glycogen may be used as a potential diagnostic biomolecule for OSF and OSCC, as well as a potential prognostic factor for OSCC in the context of OSF.

Development of Epigallocatechin 3-gallate-Loaded Hydrogel Nanocomposites for Oral Submucous Fibrosis.

Oral submucous fibrosis (OSF) is a chronic progressive disease associated with increased collagen deposition and TGF-ß1 release. The current therapy and management have been a limited success due to low efficacy and adverse drug reactions. This study aimed to evaluate epigallocatechin 3-gallate (EGCG) encapsulated nanoparticles loaded mucoadhesive hydrogel nanocomposite (HNC) for OSF. Developed HNC formulations were evaluated for their permeation behaviour using in vitro as well as ex vivo studies, followed by evaluation of efficacy and safety by in vivo studies using areca nut extract-induced OSF in rats. The disease condition in OSF-induced rats was assessed by mouth-opening and biochemical markers. The optimized polymeric nanoparticles exhibited the required particle size (162.93 ± 13.81 nm), positive zeta potential (22.50 ± 2.94 mV) with better mucoadhesive strength (0.40 ± 0.002 N), and faster permeation due to interactions of the positively charged surface with the negatively charged buccal mucosal membrane. HNC significantly improved disease conditions by reducing TGF-ß1 and collagen concentration without showing toxicity and reverting the fibroid buccal mucosa to normal. Hence, the optimized formulation can be further tested to develop a clinically alternate therapeutic strategy for OSF.

Salivary transforming growth factor beta in oral submucous fibrosis: A diagnostic and predictive marker.

CONTEXT: Growth factors and cytokines like transforming growth factor beta (TGF-ß) play a key role in the pathogenesis of oral submucous fibrosis. AIMS: To elucidate the role of Salivary TGF-ß isoforms as a predictive and diagnostic marker for oral submucous fibrosis. SETTINGS AND DESIGN: A total of 30 OSMF and 10 control patients were included in this study, and their clinic-epidemiological data was recorded. METHODOLOGY: The expression of TGF-ß genes-TGF-ß1, TGF-ß2, TGF-ß3-was studied by a real-time polymerase chain reaction in tissue and saliva. Patients were given medicinal intervention for 12 weeks along with jaw-opening exercises. Expression of salivary TGF-ß genes was studied at 12 weeks. STATISTICAL ANALYSIS USED: SPSS software version 20. RESULT: Expression of salivary TGF beta isoforms in OSMF was more than in the control group. There was an increase in salivary TGF-ß1, ß2, ß3 expressions with increasing clinical grades of OSMF and advancing the stage of the disease. Expression of all the TGF beta isoforms was decreased after treatment with statistically significant results. Statistically significant correlations were found between the mean difference of TGF-ß1 and the mean difference between mouth opening and tongue protrusion. CONCLUSION: Salivary TGF-ß isoforms may be used in diagnosis, risk assessment, and screening of the entire population at risk of OSMF after its clinical validation. However, adequate sample size and segmental assessment of the expression of TGF-ß isoforms are needed for further evaluation.

An enigmatic pathogenetic mechanism of hypoxia inducible factor - 1/2 alpha in the progression of fibrosis of oral submucous fibrosis and its malignant transformation: A systematic review and meta-analysis.

OBJECTIVE: Oral submucous fibrosis is a frequently reported potentially malignant disorder characterized by fibrosis and a malignant transformation rate of 7-30%. The role of hypoxia-inducible factor-1/2α in malignant transformation mechanisms of oral submucous fibrosis remains uncharted territory owing to a scarcity of studies. Thus the present systematic review and meta-analysis aimed to determine the role of hypoxia-inducible factor-1/2α in the progression of fibrosis of oral submucous fibrosis and its malignant transformation. MATERIAL AND METHODS: Using PubMed, Google Scholar, and Cochrane Library databases, full-text articles that investigated hypoxia-inducible factor-1/2α in oral submucous fibrosis were entailed for review. A modified Newcastle-Ottawa scale was employed to evaluate risk of bias in all articles and Review Manager was utilized for meta-analysis. RESULTS: Eighteen and eight qualified articles respectively were included for qualitative and quantitative data synthesis. Progressive upregulation of hypoxia-inducible factor-1/2α in oral submucous fibrosis is associated with fibrosis-induced carcinogenesis. A Random-effects model uncloaked that oral submucous fibrosis cases with significantly increased expression of hypoxia-inducible factor-1α had an increased associated risk of malignant transformation compared with controls (combined odds ratio 523.83, 95% confidence interval 125.74- 2182.28, p < 0.00001). CONCLUSION: The existing evidence substantiates the notion that hypoxia-inducible factor-1/2α, a fundamental pathogenetic mechanism of progression and malignant transformation of oral submucous fibrosis in the background of fibrosis.

Linking inflammation and angiogenesis with fibrogenesis: Expression of FXIIIA, MMP-9, and VEGF in oral submucous fibrosis / Vinculación de la inflamación y la angiogénesis con la fibrogénesis: expresión de FXIIIA, MMP-9 y VEGF en la fibrosis submucosa oral

Objectives Interplay of Factor XIIIa (FXIIIa), a transglutaminase, responsible for cross-linking of matrix proteins, Matrix Metalloproteinase-9 (MMP-9), a gelatinase, and Vascular Endothelial Growth Factor (VEGF), an angiogenic inducer, were studied in relation to fibrogenesis and disease progression in oral submucous fibrosis (OSMF). Material and methods Immunohistochemical expression of markers was studied in 60 formalin-fixed paraffin-embedded tissue blocks of OSMF and 20 normal oral mucosal tissues. FXIIIa was studied quantitatively while MMP-9 and VEGF were assessed semi-quantitatively. Expression was compared with histopathological grades of OSMF. Results FXIIIa expression significantly increased in OSMF (p-value 0.000). However, expression decreased and cells became quiescent with increasing grades (p-value 0.000). MMP-9 (p-value epithelium 0.011, p-value connective tissue 0.000) and VEGF expression (p-value epithelium 0.000, connective tissue 0.000) increased in OSMF. A negative correlation between FXIIIa and MMP-9 (−0.653) in early grade (p-value of 0.021) and a positive correlation between FXIIIa and VEGF (0.595) (p-value of 0.032) was found in the moderate grade OSMF. Regression analysis showed a significant association (p<0.01) of FXIIIa in OSMF and with increasing grades of OSMF. Conclusion FXIIIa may play a crucial role in initiation of fibrosis in OSMF. MMP-9 may have a diverse role to play in OSMF as a regulator of fibrosis. VEGF may show an angio-fibrotic switch and contribute to fibrosis in OSMF. These cytokines may show altered function and can contribute to fibrosis and chronicity of disease due to changes in the microenvironment. Tissue stiffness in OSMF itself creates an environment that enhances the chronicity of the disease. (AU)

Objetivos Se estudió la interacción del factor XIIIa (FXIIIa), una transglutaminasa responsable de los entrecruzamientos de las proteínas de la matriz, la metaloproteinasa de matriz-9 (MMP-9), una gelatinasa y el factor de crecimiento endotelial vascular (VEGF), un inductor angiogénico, en relación con la fibrogénesis y la progresión de la enfermedad en la fibrosis submucosa oral (OSMF). Material y métodos Se estudió la expresión inmunohistoquímica de marcadores en 60 bloques de tejido de OSMF fijados con formalina e incluidos en parafina y 20 tejidos de mucosa oral normales. FXIIIa se estudió cuantitativamente mientras que MMP-9 y VEGF se evaluaron semicuantitativamente. La expresión se comparó con los grados histopatológicos de OSMF. Resultados La expresión de FXIIIa aumentó significativamente en OSMF (valor de p 0,000). Sin embargo, la expresión disminuyó y las células se volvieron inactivas a medida que aumentaban los grados (valor de p 0,000). MMP-9 (valor de p epitelio 0,011, tejido conectivo valor de p 0,000) y expresión de VEGF (valor de p epitelio 0,000, tejido conectivo 0,000) aumentaron en OSMF. Se encontró una correlación negativa entre FXIIIa y MMP-9 (-0,653) en grado temprano (valor de p de 0,021) y una correlación positiva entre FXIIIa y VEGF (0,595) (valor de p de 0,032) en OSMF de grado moderado. El análisis de regresión mostró una asociación significativa (p<0,01) de FXIIIa en OSMF y con grados crecientes de OSMF. Conclusión FXIIIa puede desempeñar un papel crucial en el inicio de la fibrosis en OSMF. MMP-9 puede desempeñar un papel diverso en OSMF como regulador de la fibrosis. VEGF puede mostrar un interruptor angiofibrótico y contribuir a la fibrosis en OSMF. Estas citocinas pueden mostrar una función alterada y pueden contribuir a la fibrosis y la cronicidad de la enfermedad debido a cambios en el microambiente. La rigidez del tejido en el propio OSMF crea un entorno que mejora la cronicidad de la enfermedad. (AU)

Association of Oral Submucous Fibrosis Risk with GSTM1 and GSTT1 Gene Polymorphisms.

OBJECTIVE: To determine the association of GSTM1 and GSTT1 polymorphisms with oral submucous fibrosis (OSF). STUDY DESIGN: A case-control study. Place and Duration of the Study: Department of Human Genetics and Molecular Biology, University of Health Sciences, Lahore and Oral and Maxillofacial Surgery Department, de Montmorency, College of Dentistry/ Punjab Dental Hospital, Lahore, Pakistan, from 1st April 2019 to 31st April 2020. METHODOLOGY: OSF patients were diagnosed with different clinical staging of mouth opening by Vernier caliper with the help of a professional dentist in the Department of Oral and Maxillofacial, de Montmorency, College of Dentistry, Lahore. One hundred and eight blood samples of OSF patients and 108 samples of normal controls were collected. Genomic DNA was obtained from whole-blood extraction. Multiplex PCR amplification using GSTM1, GSTT1, and ß -Globin gene primers was performed. RESULTS: GSTM1 and GSTT1 null genotypes frequencies were found in 43.5% (47/108) and 13.9% (15/108) of controls, whereas 54.6% (59/108) and 25.9% (28/108) of OSF patients, respectively. OSF patients had a greater frequency rate of GSTM1 and GSTT1 null genotypes than controls [OR 1.56, 95% CI 0.91-2.67 (p=0.13)] and [OR 2.17, 95% CI 1.08-4.34 (p=0.04)], respectively. The GSTT1 genotype was found statistically significant with OSF (p=0.05), and risk was also determined. The cumulative effect of null genotypes of GSTM1/GSTT1 did not show any association with the controls and in OSF patients. Proportions of active and null alleles of the patient group were; 86.1%/13.9%; and in control, it was 92.6%/7.4% (OR = 2.01; CI: 0.82-4.97; p=0.18), respectively. CONCLUSION: The study determined a statistically significant association of GSTT1 gene polymorphism with OSF. KEY WORDS: Oral submucous fibrosis, GSTM1, GSTT1, Gene polymorphisms, Genetic risk.

Linking inflammation and angiogenesis with fibrogenesis: Expression of FXIIIA, MMP-9, and VEGF in oral submucous fibrosis / Vinculación de la inflamación y la angiogénesis con la fibrogénesis: expresión de FXIIIA, MMP-9 y VEGF en la fibrosis submucosa oral

Objectives Interplay of Factor XIIIa (FXIIIa), a transglutaminase, responsible for cross-linking of matrix proteins, Matrix Metalloproteinase-9 (MMP-9), a gelatinase, and Vascular Endothelial Growth Factor (VEGF), an angiogenic inducer, were studied in relation to fibrogenesis and disease progression in oral submucous fibrosis (OSMF). Material and methods Immunohistochemical expression of markers was studied in 60 formalin-fixed paraffin-embedded tissue blocks of OSMF and 20 normal oral mucosal tissues. FXIIIa was studied quantitatively while MMP-9 and VEGF were assessed semi-quantitatively. Expression was compared with histopathological grades of OSMF. Results FXIIIa expression significantly increased in OSMF (p-value 0.000). However, expression decreased and cells became quiescent with increasing grades (p-value 0.000). MMP-9 (p-value epithelium 0.011, p-value connective tissue 0.000) and VEGF expression (p-value epithelium 0.000, connective tissue 0.000) increased in OSMF. A negative correlation between FXIIIa and MMP-9 (−0.653) in early grade (p-value of 0.021) and a positive correlation between FXIIIa and VEGF (0.595) (p-value of 0.032) was found in the moderate grade OSMF. Regression analysis showed a significant association (p<0.01) of FXIIIa in OSMF and with increasing grades of OSMF. Conclusion FXIIIa may play a crucial role in initiation of fibrosis in OSMF. MMP-9 may have a diverse role to play in OSMF as a regulator of fibrosis. VEGF may show an angio-fibrotic switch and contribute to fibrosis in OSMF. These cytokines may show altered function and can contribute to fibrosis and chronicity of disease due to changes in the microenvironment. Tissue stiffness in OSMF itself creates an environment that enhances the chronicity of the disease. (AU)

Objetivos Se estudió la interacción del factor XIIIa (FXIIIa), una transglutaminasa responsable de los entrecruzamientos de las proteínas de la matriz, la metaloproteinasa de matriz-9 (MMP-9), una gelatinasa y el factor de crecimiento endotelial vascular (VEGF), un inductor angiogénico, en relación con la fibrogénesis y la progresión de la enfermedad en la fibrosis submucosa oral (OSMF). Material y métodos Se estudió la expresión inmunohistoquímica de marcadores en 60 bloques de tejido de OSMF fijados con formalina e incluidos en parafina y 20 tejidos de mucosa oral normales. FXIIIa se estudió cuantitativamente mientras que MMP-9 y VEGF se evaluaron semicuantitativamente. La expresión se comparó con los grados histopatológicos de OSMF. Resultados La expresión de FXIIIa aumentó significativamente en OSMF (valor de p 0,000). Sin embargo, la expresión disminuyó y las células se volvieron inactivas a medida que aumentaban los grados (valor de p 0,000). MMP-9 (valor de p epitelio 0,011, tejido conectivo valor de p 0,000) y expresión de VEGF (valor de p epitelio 0,000, tejido conectivo 0,000) aumentaron en OSMF. Se encontró una correlación negativa entre FXIIIa y MMP-9 (-0,653) en grado temprano (valor de p de 0,021) y una correlación positiva entre FXIIIa y VEGF (0,595) (valor de p de 0,032) en OSMF de grado moderado. El análisis de regresión mostró una asociación significativa (p<0,01) de FXIIIa en OSMF y con grados crecientes de OSMF. Conclusión FXIIIa puede desempeñar un papel crucial en el inicio de la fibrosis en OSMF. MMP-9 puede desempeñar un papel diverso en OSMF como regulador de la fibrosis. VEGF puede mostrar un interruptor angiofibrótico y contribuir a la fibrosis en OSMF. Estas citocinas pueden mostrar una función alterada y pueden contribuir a la fibrosis y la cronicidad de la enfermedad debido a cambios en el microambiente. La rigidez del tejido en el propio OSMF crea un entorno que mejora la cronicidad de la enfermedad. (AU)

Interventions for managing oral submucous fibrosis.

BACKGROUND: Oral submucous fibrosis (OSF) is a chronic disease of the oral cavity that causes progressive constriction of the cheeks and mouth accompanied by severe pain and reduced mouth opening. OSF has a significant impact on eating and swallowing, affecting quality of life. There is an increased risk of oral malignancy in people with OSF. The main risk factor for OSF is areca nut chewing, and the mainstay of treatment has been behavioural interventions to support habit cessation. This review is an update of a version last published in 2008. OBJECTIVES: To evaluate the benefits and harms of interventions for the management of oral submucous fibrosis. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 5 September 2022. SELECTION CRITERIA: We considered randomised controlled trials (RCTs) of adults with a biopsy-confirmed diagnosis of OSF treated with systemic, locally delivered or topical drugs at any dosage, duration or delivery method compared against placebo or each other. We considered surgical procedures compared against other treatments or no active intervention. We also considered other interventions such as physiotherapy, ultrasound or alternative therapies. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. participant-reported resumption of normal eating, chewing and speech; 2. change or improvement in maximal mouth opening (interincisal distance); 3. improvement in range of jaw movement; 4. change in severity of oral/mucosal burning pain/sensation; 5. ADVERSE EFFECTS: Our secondary outcomes were 6. quality of life; 7. postoperative discomfort or pain as a result of the intervention; 8. participant satisfaction; 9. hospital admission; 10. direct costs of medication, hospital bed days and any associated inpatient costs for the surgical interventions. We used GRADE to assess certainty of evidence for each outcome. MAIN RESULTS: We included 30 RCTs (2176 participants) in this updated review. We assessed one study at low risk of bias, five studies at unclear risk of bias and 24 studies at high risk of bias. We found diverse interventions, which we categorised according to putative mechanism of action. We present below our main findings for the comparison 'any intervention compared with placebo or no active treatment' (though most trials included habit cessation for all participants). Results for head-to-head comparisons of active interventions are presented in full in the main review. Any intervention versus placebo or no active treatment Participant-reported resumption of normal eating, chewing and speech No studies reported this outcome. Interincisal distance Antioxidants may increase mouth opening (indicated by interincisal distance (mm)) when measured at less than three months (mean difference (MD) 3.11 mm, 95% confidence interval (CI) 0.46 to 5.77; 2 studies, 520 participants; low-certainty evidence), and probably increase mouth opening slightly at three to six months (MD 8.83 mm, 95% CI 8.22 to 9.45; 3 studies, 620 participants; moderate-certainty evidence). Antioxidants may make no difference to interincisal distance at six-month follow-up or greater (MD -1.41 mm, 95% CI -5.74 to 2.92; 1 study, 90 participants; low-certainty evidence). Pentoxifylline may increase mouth opening slightly (MD 1.80 mm, 95% CI 1.02 to 2.58; 1 study, 106 participants; low-certainty evidence). However, it should be noted that these results are all less than 10 mm, which could be considered the minimal change that is meaningful to someone with oral submucous fibrosis. The evidence was very uncertain for all other interventions compared to placebo or no active treatment (intralesional dexamethasone injections, pentoxifylline, hydrocortisone plus hyaluronidase, physiotherapy). Burning sensation Antioxidants probably reduce burning sensation visual analogue scale (VAS) scores at less than three months (MD -30.92 mm, 95% CI -31.57 to -30.27; 1 study, 400 participants; moderate-certainty evidence), at three to six months (MD -70.82 mm, 95% CI -94.39 to -47.25; 2 studies, 500 participants; moderate-certainty evidence) and at more than six months (MD -27.60 mm, 95% CI -36.21 to -18.99; 1 study, 90 participants; moderate-certainty evidence). The evidence was very uncertain for the other interventions that were compared to placebo and measured burning sensation (intralesional dexamethasone, vasodilators). Adverse effects Fifteen studies reported adverse effects as an outcome. Six of these studies found no adverse effects. One study evaluating abdominal dermal fat graft reported serious adverse effects resulting in prolonged hospital stay for 3/30 participants. There were mild and transient general adverse effects to systemic drugs, such as dyspepsia, abdominal pain and bloating, gastritis and nausea, in studies evaluating vasodilators and antioxidants in particular. AUTHORS' CONCLUSIONS: We found moderate-certainty evidence that antioxidants administered systemically probably improve mouth opening slightly at three to six months and improve burning sensation VAS scores up to and beyond six months. We found only low/very low-certainty evidence for all other comparisons and outcomes. There was insufficient evidence to make an informed judgement about potential adverse effects associated with any of these treatments. There was insufficient evidence to support or refute the effectiveness of the other interventions tested. High-quality, adequately powered intervention trials with a low risk of bias that compare biologically plausible treatments for OSF are needed. It is important that relevant participant-reported outcomes are evaluated.

Evaluation of possible role of fluoride in pathogenesis of oral submucous fibrosis: A pilot study.

BACKGROUND: Oral submucous fibrosis (OSMF) is a potentially malignant disorder. Although areca nut chewing is an established risk factor, its low prevalence among nut chewers indicates additional factors likely facilitates pathogenesis. We recently demonstrated high fluoride levels in smokeless tobacco products and hypothesized a potential pathological role of fluoride in OSMF. Further exploring this novel role, this study compared fluoride levels in tissue, serum, and saliva samples from OSMF patients and healthy controls. METHODS: The ethically approved study included 25 clinically confirmed OSMF patients and 25 healthy matched controls. OSMF cases underwent buccal mucosal incisional biopsy, while controls had buccal mucosa tissue sampling during third molar removal. Fasting venous blood and unstimulated saliva were collected. Fluoride levels were analysed using ion chromatography and expressed as median (IQR). RESULTS: OSMF cases showed significantly higher fluoride concentrations compared with controls in tissue biopsies (30.1 vs. 0 mg/kg, p < 0.0001), serum (0.4 vs. 0 mg/L, p = 0.005) and saliva (1.3 vs. 0 mg/L, p < 0.0001). Majority (68%) of controls had undetectable fluoride levels across all samples. Tissue fluoride weakly correlated with OSMF severity (r = -0.158, p = 0.334). CONCLUSION: The preliminary findings demonstrated increased tissue fluoride levels in OSMF patients compared with healthy controls. Along with a previous study showing high fluoride content in smokeless tobacco products, these findings provided early evidence suggesting fluoride could play a contributory role in OSMF pathogenesis. Further large-scale investigation is warranted to definitively establish whether the association between fluoride exposure and OSMF is indicative of causation.

Antifibrotic effect of silymarin on arecoline-induced fibrosis in primary human buccal fibroblasts: an in silico and in vitro analysis.

BACKGROUND: This study aimed to assess silymarin's anticancer and antifibrotic potential through in silico analysis and investigate its impact on in vitro arecoline-induced fibrosis in primary human buccal fibroblasts (HBF). METHODS & RESULTS: The study utilized iGEMDOCK for molecular docking, evaluating nine bioflavonoids, and identified silymarin and baicalein as the top two compounds with the highest target affinity, followed by subsequent validation through a 100ns Molecular Dynamic Simulation demonstrating silymarin's stable behavior with Transforming Growth Factor Beta. HBF cell lines were developed from tissue samples obtained from patients undergoing third molar extraction. Arecoline, a known etiological factor in oral submucous fibrosis (OSMF), was employed to induce fibrogenesis in these HBFs. The inhibitory concentration (IC50) of arecoline was determined using the MTT assay, revealing dose-dependent cytotoxicity of HBFs to arecoline, with notable cytotoxicity observed at concentrations exceeding 50µM. Subsequently, the cytotoxicity of silymarin was assessed at 24 and 72 h, spanning concentrations from 5µM to 200µM, and an IC50 value of 143µM was determined. Real-time polymerase chain reaction (qPCR) was used to analyze the significant downregulation of key markers including collagen, epithelial-mesenchymal transition (EMT), stem cell, hypoxia, angiogenesis and stress markers in silymarin-treated arecoline-induced primary buccal fibroblast cells. CONCLUSION: Silymarin effectively inhibited fibroblast proliferation and downregulated genes associated with cancer progression and EMT pathway, both of which are implicated in malignant transformation. To our knowledge, this study represents the first exploration of silymarin's potential as a novel therapeutic agent in an in vitro model of OSMF.

[Oral squamous cell carcinoma in the background of oral submucous fibrosis - a systematic review]. / Skvamozno-kletochnaya kartsinoma polosti rta na fone podslizistogo fibroza polosti rta - sistematicheskii obzor.

Oral squamous cell carcinoma (OSCC) in the background of oral submucous fibrosis (OSMF) is one of the most common presentations of oral cancer among Asian population. OSCC arising in the background of OSMF (OSCC with OSMF) has been a topic of interest among researchers recently and a few studies have considered this to be a distinct clinicopathological entity. This systematic review analyses the demographic and clinicopathological variations of OSCC with OSMF from conventional OSCC to evaluate the distinctiveness of OSCC with OSMF. A comprehensive search from PubMed, Google scholar and manual search were carried out and 4 articles were retrieved and analysed systematically. Out of the total 377 OSCC with OSMF cases and 542 conventional OSCC, males were found to be predominantly affected (82.7% and 73.6%). 47% of the OSCC with OSMF cases were well differentiated squamous cell carcinomas as against 33.4% in conventional OSCC. Lymph node metastases were seen predominantly in conventional OSCC (49.1%) than OSCC with OSMF cases (40.7%). OSCC with OSMF were more prevalent in males and showed better tumour differentiation and lesser lymph node metastasis. Even though the present results inculpate OSCC with OSMF as a distinct clinicopathological entity, there is a dire need for thorough investigation.

Stromal thrombospondin 1 suppresses angiogenesis in oral submucous fibrosis.

A decline in mucosal vascularity is a histological hallmark of oral submucous fibrosis (OSF), a premalignant disease that is largely induced by betel quid chewing. However, the lack of available models has challenged studies of angiogenesis in OSF. Here, we found that the expression of thrombospondin 1 (THBS1), an endogenous angiostatic protein, was elevated in the stroma of tissues with OSF. Using a fibroblast-attached organoid (FAO) model, the overexpression of THBS1 in OSF was stably recapitulated in vitro. In the FAO model, treatment with arecoline, a major pathogenic component in areca nuts, enhanced the secretion of transforming growth factor (TGF)-ß1 by epithelial cells, which then promoted the expression of THBS1 in fibroblasts. Furthermore, human umbilical vein endothelial cells (HUVECs) were incorporated into the FAO to mimic the vascularized component. Overexpression of THBS1 in fibroblasts drastically suppressed the sprouting ability of endothelial cells in vascularized FAOs (vFAOs). Consistently, treatment with arecoline reduced the expression of CD31 in vFAOs, and this effect was attenuated when the endothelial cells were preincubated with neutralizing antibody of CD36, a receptor of THBS1. Finally, in an arecoline-induced rat OSF model, THBS1 inhibition alleviated collagen deposition and the decline in vascularity in vivo. Overall, we exploited an assembled organoid model to study OSF pathogenesis and provide a rationale for targeting THBS1.

PDE12 disrupts mitochondrial oxidative phosphorylation and mediates mitochondrial dysfunction to induce oral mucosal epithelial barrier damage in oral submucous fibrosis.

Oral submucous fibrosis (OSF) is a chronic oral mucosal disease. The pathological changes of OSF include epithelial damage and subepithelial matrix fibrosis. This study aimed to reveal the epithelial injury mechanism of OSF. A histopathological method was used to analyze oral mucosal tissue from OSF patients and OSF rats. The expression of PDE12 in the oral epithelium was analyzed by immunohistochemistry. The epithelial-mesenchymal transition (EMT) and tight junction proteins in arecoline-treated HOKs were explored by western blotting. Epithelial leakage was assessed by transepithelial electrical resistance and lucifer yellow permeability. The expression of PDE12 and the mitochondrial morphology, mitochondrial permeability transition pore opening, mitochondrial membrane potential, and mitochondrial reactive oxygen species (mtROS) were evaluated in arecoline-induced HOKs. Oxidative phosphorylation (OXPHOS) complexes and ATP content were also explored in HOKs. The results showed significant overexpression of PDE12 in oral mucosal tissue from OSF patients and rats. PDE12 was also overexpressed and aggregated in mitochondria in arecoline-induced HOKs, resulting in dysfunction of OXPHOS and impaired mitochondrial function. An EMT, disruption of tight junctions with epithelial leakage, and extracellular matrix remodeling were also observed. PDE12 overexpression induced by PDE12 plasmid transfection enhanced the mtROS level and interfered with occludin protein localization in HOKs. Interestingly, knockdown of PDE12 clearly ameliorated arecoline-induced mitochondrial dysfunction and epithelial barrier dysfunction in HOKs. Therefore, we concluded that overexpression of PDE12 impaired mitochondrial OXPHOS and mitochondrial function and subsequently impaired epithelial barrier function, ultimately leading to OSF. We suggest that PDE12 may be a new potential target against OSF.

Spatial Transcriptomic and Metabolomic Landscapes of Oral Submucous Fibrosis-Derived Oral Squamous Cell Carcinoma and its Tumor Microenvironment.

In South and Southeast Asia, the habit of chewing betel nuts is prevalent, which leads to oral submucous fibrosis (OSF). OSF is a well-established precancerous lesion, and a portion of OSF cases eventually progress to oral squamous cell carcinoma (OSCC). However, the specific molecular mechanisms underlying the malignant transformation of OSCC from OSF are poorly understood. In this study, the leading-edge techniques of Spatial Transcriptomics (ST) and Spatial Metabolomics (SM) are integrated to obtain spatial location information of cancer cells, fibroblasts, and immune cells, as well as the transcriptomic and metabolomic landscapes in OSF-derived OSCC tissues. This work reveals for the first time that some OSF-derived OSCC cells undergo partial epithelial-mesenchymal transition (pEMT) within the in situ carcinoma (ISC) region, eventually acquiring fibroblast-like phenotypes and participating in collagen deposition. Complex interactions among epithelial cells, fibroblasts, and immune cells in the tumor microenvironment are demonstrated. Most importantly, significant metabolic reprogramming in OSF-derived OSCC, including abnormal polyamine metabolism, potentially playing a pivotal role in promoting tumorigenesis and immune evasion is discovered. The ST and SM data in this study shed new light on deciphering the mechanisms of OSF-derived OSCC. The work also offers invaluable clues for the prevention and treatment of OSCC.

Lesion size affects the risk of technical difficulty in gastric endoscopic submucosal dissection.

Current evidence shows an inter-country inconsistency in the effect of lesion size on the technical difficulty of gastric endoscopic submucosal dissection (ESD). We aimed to evaluate the specific correlation and quantify the ensuing risks. This retrospective study consisted of 405 ESD cases with gastric single lesion from April 2015 to April 2023. The correlation and risk prediction of lesion size with technical difficulty was explored to provide further clinical evidence. An additive generalized model and recursive algorithm were used to describe the non-linear association, and a linear two-piece regression was constructed to analyze the inflection point. Subgroup analysis and interaction were used to explore intergroup characteristics. Overall, difficult cases had larger lesion sizes, and the more significant the increase, the higher the risk of technical difficulty. In the full model, after adjusting for all covariates, each 1 mm, 3 mm, 5 mm, 7 mm, and one standard increase in lesion size increased the risk of technical difficulty by 8%, 26%, 42%, 72%, and 125%, respectively. There is a nonlinear positive correlation between lesion size and risk of technical difficulty, and the premeditated inflection point was 40 (mm) via two-piecewise linear regression and recursive algorithm. Subgroup analysis showed a stronger correlation between lesion size and difficult ESD in the upper site and submucosal fibrosis groups. Available evidence suggests that lesion size as a risk signal nonlinearly increases the technical difficulty of gastric ESD procedure, especially in cases of upper site and submucosal fibrosis, which deserves further investigation.