Oral Mucosal Epithelial Cells Research Articles

The mechanism of low molecular weight fucoidan-incorporated nanofiber scaffolds inhibiting oral leukoplakia via SR-A/Wnt signal axis

Oral leukoplakia (OLK) is the most common oral precancerous lesion, and 3%–17% of OLK patients progress to oral squamous cell carcinoma. OLK is susceptible to recurrence and has no effective treatment. However, conventional drugs have significant side effects and limitations. Therefore, it is important to identify drugs that target OLK. In this study, scavenger receptor A (SR-A) was found to be abnormally highly expressed in the oral mucosal epithelial cells of OLK patients, whereas molecular biology studies revealed that low molecular weight fucoidan (LMWF) promoted apoptosis of dysplastic oral keratinocytes (DOK) and inhibited the growth and migration of DOK, and the inhibitory effect of LMWF on OLK was achieved by regulating the SR-A/Wnt signaling axis and related genes. Based on the above results and the special situation of the oral environment, we constructed LMWF/poly(caprolactone-co-lactide) nanofiber membranes with different structures for the in-situ treatment of OLK using electrospinning technology. The results showed that the nanofiber membranes with a shell-core structure had the best physicochemical properties, biocompatibility, and therapeutic effect, which optimized the LMWF drug delivery and ensured the effective concentration of the drug at the target point, thus achieving precise treatment of local lesions in the oral cavity. This has potential application value in inhibiting the development of OLK.

Identification of activating transcription factor 6 (ATF6) as a novel prognostic biomarker and potential target in oral squamous cell carcinoma

BackgroundOral squamous cell carcinoma (OSCC) is originating from oral mucosal epithelial cells. Autophagy plays a crucial role in cancer treatment by promoting cellular self-degradation and eliminating damaged components, thereby enhancing therapeutic efficacy. In this study, we aim to identify a novel autophagy-related biomarker to improve OSCC therapy. MethodsWe firstly utilized Cox and Lasso analyses to identify that ATF6 is associated with OSCC prognosis, and validated the results by Kaplan-Meier survival analysis. We further identified the downstream pathways and related genes by enrichment analysis and WGCNA analysis. Subsequently, we used short interfering RNA to investigate the effects of ATF6 knockdown on proliferation, migration, apoptosis, and autophagy in SCC-9 and SCC-15 cells through cell viability assay, transwell assay, EdU incorporation assay, flow cytometry analysis, western blot analysis and immunofluorescence analysis, etc. ResultsBioinformatics analyses showed that ATF6 overexpression was associated with prognosis and detrimental to survival. In vitro studies verified that ATF6 knockdown reduced OSCC cell proliferation and migration. Mechanistically, ATF6 knockdown could promote cellular autophagy and apoptosis. ConclusionWe propose that ATF6 holds potential as a prognostic biomarker linked to autophagy in OSCC. This study provides valuable clues for further exploration of targeted therapy against OSCC.

Lessons learned from contamination with endotoxin originated from the supplement in the cell culture medium

IntroductionEndotoxin is a typical pyrogen derived from the outer membrane of Gram-negative bacteria. In fabricating cell-based medicinal products, it is necessary to control endotoxin in the process and the products. In the quality control tests of our clinical study, endotoxin concentration in the culture supernatant of autologous oral mucosal epithelial cell sheets exceeded the criterion value. Therefore, endotoxin measurements were conducted to clarify the cause of the endotoxin contamination. MethodsThe reagents used to prepare the culture medium, the unused culture medium, and the culture supernatants were diluted with pure water. Endotoxin concentrations in the diluted samples were measured. ResultsEndotoxin was detected in both the unused culture medium and the culture supernatant of the epithelial cell sheets at higher concentrations than the criterion value. Therefore, endotoxin concentrations in the reagents used to prepare the culture medium were measured and were found to be below the criterion value, except for cholera toxin. On the other hand, three lots of cholera toxin products were used for the measurement, and the endotoxin concentrations were higher than the criterion value. The results indicate that the endotoxin contamination is caused by the cholera toxin product. ConclusionsTo prevent endotoxin contamination in cell-based medicinal products, endotoxin concentrations in reagents used for the fabrication should be measured in the facility conducting clinical research or confirmed by an adequate certificate of analysis from the manufacturers of the reagents.

Cytomorphometric analysis of buccal mucosal cells in iron deficiency anemia: A cross-sectional study.

Worldwide, at any given moment, more individuals have iron deficiency anemia (IDA) than any other health problems. Very few studies have been conducted to evaluate changes in oral mucosa in IDA. The present study is undertaken for cytomorphometric analysis of buccal mucosal cells in IDA. Nuclear diameter (ND), cell diameter (CD), nuclear area (NA), cell area (CA), and nuclear-cytoplasmic ratio (N/C) are measured and compared in buccal mucosal cells of IDA patients and controls. To evaluate cytomorphometric changes in epithelial cells of oral mucosa in IDA and to compare these changes with the controls. A cross-sectional study. Forty cases of IDA and forty cases of control group were selected for the study. IDA cases were diagnosed with decreased Hb level, MCV, MCH, MCHC and confirmed by decreased serum iron and increased total iron-binding capacity levels. Cytomorphometric analysis of buccal mucosa was performed to study CA, CD, NA, ND, and N/C ratio. Statistical analysis was done using t- test in SPSS software version 4. Results of our study showed increased cell area, cell diameter, nuclear area, nuclear diameter, and nuclear-cytoplasmic ratio in anemic group as compared to controls. The study suggests that individuals with IDA regardless of clinically visible oral lesions show cytological changes in oral mucosal epithelium. Knowledge of quantitative alterations in oral epithelial cells of IDA patients is important as these alterations are similar to those seen in precancerous and radiation-induced changes. Cytomorphometry is an efficient tool to understand the extent of cellular changes that occur in oral epithelial cells in IDA.

Fibrotic Matrix Induces Mesenchymal Transformation of Epithelial Cells in Oral Submucous Fibrosis

Oral submucous fibrosis (OSF) is a potentially malignant disorder of the oral mucosa; however, whether and how the fibrotic matrix of OSF is involved in the malignant transformation of epithelial cells remains unknown. Herein, oral mucosa tissue from patients with OSF, OSF rat models, and their controls were used to observe the extracellular matrix changes and epithelial-mesenchymal transformation (EMT) in fibrotic lesions. Compared with controls, oral mucous tissues from patients with OSF showed an increased number of myofibroblasts, a decreased number of blood vessels, and increased type I and type III collagen levels. In addition, the oral mucous tissues from humans and OSF rats showed increased stiffness, accompanied by increased EMT activities of epithelial cells. The EMT activities of stiff construct-cultured epithelial cells were increased significantly by exogenous piezo-type mechanosensitive ion channel component 1 (Piezo1) activation, and decreased by yes-associated protein (YAP) inhibition. During exvivo implantation, oral mucosal epithelial cells of the stiff group showed increased EMT activities and increased levels of Piezo1 and YAP compared with those in the sham and soft groups. These results indicate that increased stiffness of the fibrotic matrix in OSF led to increased proliferation and EMT of mucosal epithelial cells, in which the Piezo1-YAP signal transduction is important.

Description of Candida albicans Fungus in The Oral Mucosa of Patients With Fe Deficiency Anemia in RSUD Ciamis

Background & Objective Indonesia is a developing country where Fe deficiency anemia is common. Fe deficiency anemia is a malnutrition disease caused by a lack of Fe in the patient's body. Fe deficiency anemia is triggered by a lack of Fe in the body for the formation of hemoglobin, causing patients to experience blood deficiency and thinning of oral mucosal epithelial cells which can cause oral candidiasis. Analyzing the description of oral candidiasis in patients with Fe deficiency anemia. Methods This study is a descriptive study that recruited a total sampling of 17 patients with Fe deficiency anemia. Oral candidiasis in Fe deficiency anemia was measured by planting on sabouraud dextrose agar (SDA) media and sugars media then observed macroscopically and microscopically from SDA and sugars cultures using a microscope. Results Based on the results of the study, 15 (88%) positive respondents and 2 (12%) negative respondents. Conclusion The results of the examination of oral candidiasis as many as 15 samples were affected by oral candidiasis caused by Candida albicans.

Association of Prevotella intermedia with oropharyngeal cancer: A patient-control study

ObjectiveTo investigate the frequencies and bacterial load of three species of periodontal bacteria in samples from oropharyngeal cancer patients versus healthy individuals. Study designThis is a case-control study based on biopsies collected from tumor tissues obtained from patients with oropharyngeal squamous cell carcinoma between 2016 and 2017 and shed oral mucosal epithelial cells that were collected from controls using the Cepimax® brush, carrying out several brushings towards the posterior third edge of the tongue and the cheek. Porphyromonas gingivalis, Tannerella forsythia and Prevotella intermedia detection and absolute quantification was determined through q-PCR. Statistical analysis included a U- test, X2, Fisher's exact test, odds ratio (OR) and Conditional logistic regression analysis and unconditional regression analysis (p < 0.05). ResultsA total of 48 donors older than 55 years old participated in this study. The population was distributed into 24 patients (cases) and 24 controls. A robust association was established in cases and controls with significance regarding Prevotella intermedia (OR: 15.00) and Porphyromonas gingivalis (OR:11.00). In the comparison between the amount of each bacteria in the groups, P. intermedia showed a higher bacterial load in oropharyngeal cancer patients (p = 0.04). However, multivariate analysis adjusted to the presence of different bacteria and the diverse confounding variables did not reveal significant differences for oropharyngeal cancer association. ConclusionP. gingivalis and P. intermedia were detected more frequently in the group of patients with cancer. The bivariate analysis of the bacterial load evidenced significant differences for Prevotella intermedia, suggesting that it could be associated with oropharyngeal cancer.

CommerciallyA novel cultivated oral mucosal epithelial cell sheet transplantation (COMET) method using a commercially available regenerative product sheet originating from human ectopic autologous tissue

commerciallyA novel cultivated oral mucosal epithelial cell sheet transplantation (COMET) method using a commercially available regenerative product sheet originating from human ectopic autologous tissue

Thrombospondin-1 induction and VEGF reduction by proteasome inhibition

The present study focuses on investigating the expression of thrombospondin-1 (TSP-1), a natural inhibitor of neovascularization. Immunofluorescent staining was used to detect the expression of TSP-1 in rabbit corneal tissue with vascularization induced by limbectomy. TSP-1 was detected in healthy and Cultured Autologous Oral Mucosal Epithelial Cell Sheet (CAOMECS) grafted rabbit corneas. TSP-1 was not detected in diseased corneas. Rabbit and human primary oral mucosal and corneal epithelial cells were cultured and treated with proteasome inhibitor (PI) in vitro. Changes in the expression of TSP-1, HIF-1 alpha and 2 alpha, VEGF-A, and VEGF receptor were analyzed by Western blotting. Neovascularization developed in rabbits’ corneas as early as 1 month after limbectomy and was stable for at least 3 months. HIF-1 alpha and VEGF-A expression was reduced in CAOMECS grafted corneas, as compared to sham corneas. While TSP-1 expression was decreased in injured corneas, it was expressed in CAOMECS grafted corneas, but still less expressed compared to healthy corneas. PI treatment, of human oral mucosal and corneal epithelial cells increased TSP-1 expression and reduced VEGF-A expression. The results showed that TSP-1 expression was lost in injured corneal surface and that CAOMECS grafting restored TSP-1 expression to certain extent. Proteasome inhibition treatment increased TSP-1 and decreased VEGF-A expression in human oral mucosal and corneal epithelial cells. The result suggests that corneal neovascularization could be managed with the inhibition of the proteasome after CAOMECS grafting and increase corneal transparency.

Long-term outcomes of regenerative treatment by endoscopic oral mucosal epithelial cell sheet transplantation for the prevention of esophageal stricture after endoscopic resection

IntroductionWe reported the short-term outcomes of a regenerative medical treatment to prevent esophageal stricture after endoscopic submucosal dissection (ESD) using cultured tis oral mucosal epithelial cell sheets. This study investigated the long-term outcomes of this treatment. MethodsEpithelial cells, isolated from the patient's own oral mucosal tissue, were cultured for 16 days using temperature-responsive culture dishes. Then, the autologous cell sheets were endoscopically transplanted onto the bed of the esophageal ulcer after endoscopic mucosal resection (EMR) and ESD. Results of 10 patients who underwent endoscopic transplantation of oral mucosal epithelial cell sheets from April 2008 through February 2022 were recorded. We analyzed the outcome, the cause, and the endoscopic findings. ResultsThe median period of observation was 3761 days. No stricture was detected in any of the patients long-term. Two patients died because of pancreatic cancer and brainstem hemorrhage. One patient underwent chemo-radiotherapy for further treatment. The patients underwent surgery due to metastasis to the lymph nodes. Only the lymph nodes were dissected, and the esophagus remained intact. From the endoscopic findings: Melanosis was found at the transplanted site in a patient. Strong iodine staining was shown at the transplanted site in a patient. Transplantation of cultured oral mucosal epithelial cell sheets to prevent esophageal stricture has been proven to be a safe treatment. All patients showed no controlled esophageal stricture in the long term.

Expression of K-19 Cytokeratin in Gingival Epithelial Cells in Periodontal Health and Disease - An Immunohistochemical Study

Background and aim: CK19, a secondary keratin of simple epithelial cells, is the smallest cytokeratin. Its expression was observed in basal and suprabasal stratified squamous epithelial cells of oral mucosa, especially in case of inflammatory conditions and epithelial dysplasia. The aim of this analytical cross-sectional study was to investigate the expression of CK 19 in the gingival epithelial cells of healthy and periodontitis subjects and to correlate the findings with the clinical parameters. Materials and methods: The tissue samples were collected from a total of 30 patients from the healthy and periodontitis groups, during orthodontic/ 3rd molar extractions and during periodontal surgeries respectively. The tissues were then processed for immunohistochemistry analysis and the results were obtained. Results: The data obtained were statistically analysed (CHI square and ANOVA tests) and the results suggested that, there was no statistically significant difference in the expression of CK-19 between healthy and periodontitis groups. Conclusion: The results of this study further affirm the varied responses to destruction (breakdown and repair) from individual to individual during the host-microbial interactions. The mixed outcome could also be due to the suppression of overt inflammation following phase I therapy. Keywords: basal layers, cytokeratin, immunohistochemistry, inflammation, oral epithelium.

Prevention of Esophageal Stricture After Whole Circumferential Endoscopic Resection: A Review for Endoscopists.

The incidence of esophageal stricture without stricture prophylaxis measures after whole circumferential endoscopic resection is almost 100%, which substantially decreases the patients' quality of life and requires multiple sessions of endoscopic balloon dilation. To date, there are many reports concerning the prevention of esophageal stricture after whole circumferential endoscopic resection. Oral steroid may be effective for preventing esophageal stricture after whole circumferential endoscopic resection. However, exposure to a high dose of steroid raises concerns with regard to adverse events. Intralesional triamcinolone acetonide injection and preventive endoscopic balloon dilation did not appear to reduce the frequency of stricture formation after whole circumferential endoscopic resection. Esophageal stent appeared to be a possible prophylactic treatment, but adverse events should be of great concern. Polyglycolic acid sheets seemed promising, because they can not only act as protective barriers but can also be drug carriers to prevent esophageal stricture. Tissue engineering and regenerative medicine such as oral mucosal epithelial cell sheets cultured in vitro have been used in patients to prevent esophageal stricture, but it is technically and financially burdensome. Autologous tissue transplantation showed a promising preventive effect for esophageal stricture and it is relatively easy to carry out in clinical practice, and this technique needs further improvements to prevent esophageal stricture after whole circumferential endoscopic resection.

COVID-19 and oral cancer: Critical viewpoint.

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has marked the beginning of a new pandemic named coronavirus disease 2019 (COVID-19). The World Health Organization has announced it as a health emergency that is of international concern. The disease has been reported to cause respiratory illness, pneumonia and even hinder the immunity of an individual. Individuals with disturbed immune responses have been found to be quite susceptible to this viral infection. Oral cancer patients are also at high risk in this pandemic situation and might encounter severe detrimental outcomes. Angiotensin receptors, documented in studies as the path of entry of this virus, are highly expressed in the epithelial cells of oral mucosa, making the group of individuals with oral cancers even more vulnerable. Extracellular matrix metalloproteinase inducer is another potential target for SARS-CoV-2. An exhaustion of angiotensin converting enzyme 2 cell receptors leads to protumoral effects, whereas a downregulation of extracellular matrix metalloproteinase inducer leads to antitumoral effects. Thus, it causes a variation of the biological behavior of the tumor. This article focusses on the molecular mechanisms, effects and patho-physiology of COVID-19 in oral squamous cell carcinoma patients. The different molecular changes in oral squamous cell carcinoma in the background of COVID-19 will modify various environmental factors for this pathology and have an effect on the carcinogenesis process. Understanding the behavior of the tumor will help plan advanced treatment strategies for oral squamous cell carcinoma patients in the background of COVID-19.

Effects of Exosomal microRNAs on Oral Mucosal Epithelial Cells Cocultured with Limbal Niche Cells.

Autologous cultivated oral mucosal epithelial transplantation (COMET) is an important method for the treatment of limbal stem cell deficiency (LSCD), but the appearance of peripheral corneal neovascularization after COMET has prevented its widespread use in clinical practice. Using limbal niche cells (LNCs) as feeders in the process of coculturing could inhibit the postoperative corneal neovascularization. However, the specific mechanism is still unclear. In this study, LNCs were used as feeder cells to alter the phenotype of cultured oral mucosal epithelial cells (COMECs) by mimicking the primitive limbal microenvironment. The high-throughput sequencing of COMECs cocultured with LNCs or 3T3 cells (named LNCs group and 3T3 groups) was performed, and differential miRNA expression was analyzed. A total of 99 known and 1 newly predicted miRNAs were significantly upregulated in the LNCs group, while 101 known and 8 newly predicted miRNAs were significantly downregulated. A total of 3000 target genes with the 60 most significantly differentially expressed miRNAs were predicted, and 7 upregulated and 7 downregulated miRNAs were ultimately screened. The supernatants obtained from both cocultures were found to be rich in exosomes, indicating that the intercellular communication between COMECs and LNCs or 3T3 cells was highly active. Furthermore, the expression levels of rno-miR-200-5p, rno-miR-204-5p, rno-miR-126a-3p, rno-miR-192-5p, rno-miR-211-5p, rno-miR-143-3p, and rno-miR-184 were significantly higher in the LNCs group compared to the 3T3 group, and the expression levels had a similar trend in exosomes. Meanwhile, sequencing of the cell lines revealed 7 miRNAs that were significantly downregulated in the LNCs group. Interestingly, in that case, rno-miR-23a-3p, rno-miR-379-5p, and rno-miR-127-5p were also significantly downregulated in the exosomes. In summary, this study suggested that signal transduction between cells mediated by exosomal miRNAs may be an important factor for the inhibition of angiogenesis by LNCs nourished COMECs.

Human Umbilical Cord Lining-Derived Epithelial Cells: A Potential Source of Non-Native Epithelial Cells That Accelerate Healing in a Porcine Cutaneous Wound Model.

Human umbilical cord lining epithelial cells [CLECs) are naïve in nature and can be ethically recovered from cords that are routinely discarded. The success of using oral mucosal epithelial cells for cornea defects hints at the feasibility of treating cutaneous wounds using non-native CLECs. Herein, we characterized CLECs using flow cytometry (FC) and skin organotypic cultures in direct comparison with skin keratinocytes (KCs). This was followed by wound healing study to compare the effects of CLEC application and the traditional use of human skin allografts (HSGs) in a porcine wound model. While CLECs were found to express all the epidermal cell markers probed, the major difference between CLECs and KCs lies in the level of expression (in FC analysis) as well as in the location of expression (of the epithelium in organotypic cultures) of some of the basal cell markers probed. On the pig wounds, CLEC application promoted accelerated healing with no adverse reaction compared to HSG use. Though CLECs, like HSGs, elicited high levels of local and systemic immune responses in the animals during the first week, these effects were tapered off more quickly in the CLEC-treated group. Overall, the in vivo porcine data point to the potential of CLECs as a non-native and safe source of cells to treat cutaneous wounds.

Antimicrobial Effect of Extracellular Vesicles Derived From Human Oral Mucosal Epithelial Cells on Candida albicans.

Candida albicans (C. albicans) is a commensal microorganism that colonizes the mucosal surfaces of healthy individuals. Changes in the host or environment can lead to overgrowth of C. albicans and infection of the host. Extracellular vesicles (EVs) are released by almost all cell types and play an increasingly recognized role in fighting microbial infection. The aim of the present study was to assess whether EVs derived from human oral mucosal epithelial (Leuk-1) cells can suppress the growth and invasion of C. albicans. The in vitro efficacy of Leuk-1-EVs against C. albicans was assessed by optical microscopy, laser scanning confocal microscopy, scanning electron microscopy, and transmission electron microscopy. The germ tube formation rate, the percentage of hyphae and the microcolony optical density were also used to analyze the growth of C. albicans in a coculture model with Leuk-1 cells and EVs or after inhibition of the secretion of EVs. A mouse model of oral candidiasis was established and submucosal injection of Leuk-1-EVs in the tongue was performed. Macroscopic observation, H&E staining, PAS staining, and scanning electron microscopy were used to assess antifungal effects of Leuk-1-EVs in vivo. The in vitro results showed that the growth of C. albicans was inhibited and that the morphology and ultrastructure were changed following Leuk-1-EVs treatment. The in vivo results exhibited that white lesions of the tongue, C. albicans infection, and oral mucosal inflammation of the infected mice were significantly alleviated after Leuk-1-EVs treatment. We thus reveal an antifungal capability of EVs derived from oral epithelial cells against C. albicans that is mediated by direct damage effects and potential synergy between EVs and human oral mucosal epithelial cells. This finding offers an intriguing, previously overlooked method of antifungal defense against C. albicans.

Potential Role of LYN, CCL2, ITGB3 and IL6 Genes in the Immune Response of Porcine Buccal Mucosa Cells

Abstract The genes considered in this study, namely, LYN, CCL2, ITGB3 and IL6 can be related to immune response in porcine buccal mucosa cells primary cultured in vitro. These genes are also responsible for, inter alia, cell migration, differentiation, proliferation and apoptosis, intracellular signal transduction, extracellular matrix binding and wound healing. A total of 20 pubertal crossbred Landrace gilts bred on commercial farms were used to obtain buccal mucosa cell cultures, which were harvested on the 7th, 15th and 30th day after initiation of the culture. Expression levels of LYN, CCL2, ITGB3 and IL6 were evaluated employing Real-Time Quantitative Polymerase Chain Reaction. All studied genes showed expression. The expression of CCL2 on day 15 was the highest of all factors measured. The greatest difference between the measurements occurred in gene IL6, between 7th and 15th day, while the least difference between the measurements occurred in gene LYN, between 7th and 15th day. Moreover, on the 7th day, LYN presented the lowest expression among all studied genes. Although in vitro conditions are much more controlled than in vivo conditions, all the factors that may positively or negatively affect cultured cells still cannot be fully predicted. Nevertheless, LYN, CCL2, ITGB3 and IL6 are a valuable starting point for studying further immunological processes in oral mucosal epithelial cells. Given their high regenerative potential, research into them is a highly valuable source of information for future wound healing therapies, where immunological processes should be carefully considered.

Investigation of Cellular Interactions of Lipid-Structured Nanoparticles With Oral Mucosal Epithelial Cells.

Lipid-based nanosystems enable intracellular delivery of drugs in the oral cavity for the treatment of local diseases. To rationally design such systems, suitable matrix compositions and particle properties need to be identified, and manufacturing technologies that allow reproducible production have to be applied. This is a prerequisite for the reliable and predictable performance of in-vitro biological studies. Here, we showed that solid lipid nanoparticles (SLN, palmitic acid) and nanostructured lipid carriers (NLC, palmitic acid and oleic acid in different ratios) with a size of 250 nm, a negative zeta potential, and a polydispersity index (PdI) of less than 0.3 can be reproducibly prepared by high-pressure homogenization using quality by design and a predictive model. SLN and NLC were colloidally stable after contact with physiological fluid and did not form agglomerates. The in-vitro studies clearly showed that besides particle size, surface charge and hydrophobicity, matrix composition had a significant effect. More specifically, the addition of the liquid lipid oleic acid increased the cellular uptake capacity without changing the underlying uptake mechanism. Regardless of the matrix composition, caveolin-mediated endocytosis was the major route of uptake, which was confirmed by particle localization in the endoplasmic reticulum. Thus, this work provides useful insights into the optimal composition of lipid carrier systems to enhance the intracellular uptake capacity of drugs into the oral mucosa.

MUCIN 1 (MUC1) LEVELS AND GLYCOSYLATION PATTERNS IN SALIVA OF PATIENTS WITH BURNING MOUTH SYNDROME (BMS): A CASE-CONTROL STUDY

<h3>Objectives</h3> Mechanisms underlying burning mouth syndrome (BMS) remain unclear. Evidence of changes in oral mucosal epithelial cells has been found in patients with BMS. This case-control study aimed to investigate whether BMS cases have evidence of impaired mucosal barrier function compared with controls without BMS, focusing on the role of salivary mucins as a first line of defense for oral epithelial cells. <h3>Study Design</h3> A total of 50 women (22 BMS cases and 28 healthy controls) age 50 years or older were included in this study. Participants attended a clinical visit including assessment of BMS symptoms, salivary sample collection, oral examination, swab for candida detection, and DNA collection using the DNA•SAL device. Total protein concentration was measured using the bicinchoninic acid assay. MUC1 protein concentration in saliva samples was quantified by sandwich enzyme-linked immunosorbent assay (Invitrogen). Salivary glycosylation was assessed by protein-normalized dot blot against 3 lectins (Maackia Amurensis Lectin II; WGA: wheat germ agglutinin; UEA: ulex europeus agglutinin (MAL-II), WGA, and UEA). H antigen, the precursor of ABO antigens, secretor status was predicted by performing Sanger DNA sequencing of the FUT2 gene. <h3>Results</h3> The average salivary protein concentration was 1.30 mg/mL in BMS cases vs 0.94 mg/mL in controls (<i>P</i> = .15). Mann-Whitney <i>U</i> test showed a trend toward lower levels of MUC1 in BMS cases (n = 20, sum of ranks = 392.50) compared with controls (n = 24, sum of ranks = 597.50; <i>P</i> = .17). UEA, MALII, and WGA reactivities were each quantitatively lower in cases compared with controls but varied widely (<i>P</i> = NS). The percentage of nonsecretors was 23% among cases vs 38% among controls (<i>P</i> = .28). Genotype-predicted secretors had significantly higher UEA reactivity compared with nonsecretors (<i>P</i> < .001). <h3>Conclusions</h3> Our study overall found trends consistent with higher salivary protein concentration, lower salivary MUC1 levels, and salivary hypoglycosylation in BMS cases compared with controls, although no findings were statistically significant. Study limitations include subject heterogeneity and sample size. As expected, UEA levels were significantly higher in secretors compared with nonsecretors. Other aspects of the oral epithelial barrier, including the quantity of other mucins and glycosylation, remain to be examined.

Aldehyde Dehydrogenases Expression in Corneal Epithelial Cells with Limbal Stem Cell Deficiency.

Purpose: The purpose of the present study is to investigate the expression of aldehyde dehydrogenases (ALDHs) in rabbit corneas with limbal stem cell deficiency (LSCD) and corneas treated with cultured autologous oral mucosa epithelial cell sheet CAOMECS designed to reconstruct the ocular surface with LSCD. Methods: New Zealand white rabbit autologous oral mucosal epithelial cells were isolated from a buccal biopsy and cultured to be grafted back onto corneas of rabbit model of LSCD. Immunofluorescent staining and Western blot analysis were used to compare the expression of ALDH1A1 and ALDH1A3 in healthy, LSCD-diseased, CAOMECS treated corneas. Human oral mucosal and corneal epithelial cells (OMECS and CECs) were cultured and treated with retinoic acid (RA) to further investigate the expression of ALDHs. Results: In healthy corneas, ALDH1A1 and ALDH1A3 were markedly expressed in basal cells of corneal epithelium. In LSCD diseased corneas, ALDH1A1 and ALDH1A3 were markedly expressed in the conjunctivalized apical epithelial cells, the goblet cells, and the stroma. CAOMECS grafted corneas showed a decreased expression of ALDHs as compared to LSCD diseased corneas. Western blot analysis confirmed the up regulation of ALDH1A1 and ALDH1A3 expression in LSCD-diseased corneal epithelial cells. CAOMECS expressed low levels of ALDH1A1 and ALDH1A3, as compared to diseased CECs (D-CEC). When ALDH1A3 was up regulated by retinoic acid treatment in OMECS, Pax-6 expression was down regulated, suggesting a decrease in regenerative capacity when ALDH enzymes are up regulated. Conclusions: These findings report for the first time the up regulation of ALDH1A1 and ALDH1A3 in rabbit corneas with LSCD and document that CAOMECS grafting used to reconstruct corneal epithelium may reduce the expression levels of ALDH enzymes.