Non-keratinized Oral Mucosa Research Articles

Exploring the Regulators of Keratinization: Role of BMP-2 in Oral Mucosa.

The oral mucosa functions as a physico-chemical and immune barrier to external stimuli, and an adequate width of the keratinized mucosa around the teeth or implants is crucial to maintaining them in a healthy and stable condition. In this study, for the first time, bulk RNA-seq analysis was performed to explore the gene expression of laser microdissected epithelium and lamina propria from mice, aiming to investigate the differences between keratinized and non-keratinized oral mucosa. Based on the differentially expressed genes (DEGs) and Gene Ontology (GO) Enrichment Analysis, bone morphogenetic protein 2 (BMP-2) was identified to be a potential regulator of oral mucosal keratinization. Monoculture and epithelial-mesenchymal cell co-culture models in the air-liquid interface (ALI) indicated that BMP-2 has direct and positive effects on epithelial keratinization and proliferation. We further performed bulk RNA-seq of the ALI monoculture stimulated with BMP-2 in an attempt to identify the downstream factors promoting epithelial keratinization and proliferation. Analysis of the DEGs identified, among others, IGF2, ID1, LTBP1, LOX, SERPINE1, IL24, and MMP1 as key factors. In summary, these results revealed the involvement of a well-known growth factor responsible for bone development, BMP-2, in the mechanism of oral mucosal keratinization and proliferation, and pointed out the possible downstream genes involved in this mechanism.

The Correlation Between the Recurrent Aphthous Stomatitis Lesion and Quality of Life Among Productive-Age Patients

Background: Recurrent Aphthous Stomatitis (RAS) is an ulcerative disease in oral mucosa. These lesions are usually located on the non-keratinized oral mucosa with the characteristics of recurrent ulcerated lesions and the presence of pain. Some people affected by RAS will have various impacts on speech, swallowing, and chewing functions. Patients with RAS usually experience pain, and this impact greatly affects their quality of life. Objective: This study examined the relationship between RAS and patients' quality of life. Materials and Methods: This study is a cross-sectional observational study. The method of taking the subjects was done using consecutive sampling with 32 subjects. Data collection was carried out with objective and subjective data. Results: A significant relationship exists between RAS and patient quality of life p = 0.044 (Fisher's Exact Test,p0.05). There is a significant correlation between RAS and patient quality of life Spearman's correlation test, significance p0.05) with a value of p = 0.018 with a strength level of a correlation coefficient of 0.415, which means that it has a moderate level and a direction of the correlation is positive. Conclusion: Aspects of social functioning limitation and bodily pain are most influenced by the emergence of RAS lesions. There is a positive correlation between RAS and patients' quality of life.

Comprehensive cornified envelope protein profile of odontogenic keratocysts clarifies the characteristics of non-keratinized oral epithelium.

Odontogenic keratocysts constitute 10%-20% of odontogenic cysts and exhibit a distinctive corrugated parakeratinized lining epithelium. Considering that cornified envelope formation is an important phenomenon during keratinocyte differentiation, this study aimed to clarify the characteristics of cornified envelope formation in odontogenic keratocysts. We investigated the cellular distribution of cornified envelope-related proteins (transglutaminases and their substrates), as well as the upstream regulatory protein c-Fos, by immunohistochemical analysis of the lining epithelium of 20 odontogenic keratocysts. We examined the corresponding mRNA levels by quantitative polymerase chain reaction. Ten dentigerous cysts served as control non-keratinized cysts. The distributions of transglutaminase and their substrates except loricrin and small protein-rich protein 1a significantly differed between odontogenic keratocysts and dentigerous cysts. There was no significant difference in c-Fos expression between odontogenic keratocysts and dentigerous cysts. The mRNA levels of transglutaminases and their substrates were significantly higher in odontogenic keratocysts than in dentigerous cysts. However, c-Fos mRNA levels did not significantly differ between groups. Surprisingly, the overall appearance of cornified envelope-related proteins of odontogenic keratocysts was consistent with the characteristics of non-keratinized oral mucosa identified in previous studies. These findings indicate that the contribution of cornified envelope-related molecules in odontogenic keratocysts is similar to that in non-keratinized oral epithelium, rather than keratinized oral epithelium, suggesting that odontogenic keratocysts are not genuine keratinized cysts. The upregulation of cornified envelope-related genes in odontogenic epithelium could be an important pathognomonic event during odontogenic keratocyst development.

Evaluation of Mean Platelet Volume in Patients of Recurrent Aphthous Stomatitis

One of the most prevalent conditions affecting the oral mucosa is recurrent aphthous stomatitis (RAS), which is characterized by uncomfortable ulcerations on the movable or non-keratinized oral mucosa. Objective: To compare mean platelet volume (MPV) in patients of recurrent aphthous stomatitis (RAS) versus healthy control. Methods: This non-probability sampling case-control research included 56 RAS patients and 56 healthy controls. Patients who presented for dental treatment and have RAS in oral cavity were included. Patients with systemic inflammatory illnesses, autoimmune diseases like pemphigus, or infectious diseases like herpes who attended for dental treatment and exhibited RAS in the oral cavity were excluded. The healthy control group had no mouth ulcers or blood problems. A Student t-test compared MPV between cases and controls based on age, gender, and MPV. Results: The mean age of the participants was 29.35 ± 8.28 years, with 57 (50.89%) females and 55 (49.11%) males. The mean MPV in the RAS group (8.86 ± 0.33) was significantly higher (p < 0.001) than in the control group (6.95 ± 0.2). The univariable model coefficient of 1.91 (95% CI = 1.81-2.01, p < 0.001) indicates that the RAS group had a significantly higher MPV than the Control group. For gender, males had a lower MPV compared to females (β = -0.36), but it was not statistically significant (p = 0.056). Conclusions: RAS patients have higher platelet activity indicated by higher mean platelet volume (MPV) than healthy controls.

Prevalence of Recurrent Aphthous Ulcers (RAUs) in the Population of Ludhiana

Introduction: Recurrent aphthous ulcer (RAU) is one of the most common oral mucosal disorders characterized by recurrent and painful ulcerations on movable or nonkeratinized oral mucosa. It affects approximately 20% of the general population. These present as recurrent, multiple, small, round, or ovoid ulcers with circumscribed margins, having yellow or gray floors, surrounded by erythematous halos. Aims and Objectives: To compare the prevalence and occurrence of RAU among the age group from 20 to 80 years. To compare the prevalence and occurrence among the gender. To correlate the causes of the recurrent aphthous stomatitis (RAS). To check for tobacco and its role in the occurrence of RAS. Materials and Methods: A cross-sectional study was conducted, and a total of 600 questionnaire forms were distributed and filled by students (undergraduates and postgraduates), staff, skilled workers, and patients reporting to the department over a period of 3 years. Results and Discussions: In total, 71.1% had experienced oral aphthous ulcerations. When both the genders were compared, RAS more commonly affected females (60.33%) than males (39.67%). The regression coefficient for gender revealed that females were more prone to RAS than males. Conclusion: Understanding the prevalence and distribution of recurrent aphthous ulceration among the population of Ludhiana gives an indication of the section of people who suffer from the condition. Based on the results of our study, females were more commonly affected than males, and the second- and third-decades age groups were affected.

Mucoadhesive Nanocarriers as a Promising Strategy to Enhance Intracellular Delivery against Oral Cavity Carcinoma.

Oral cancer, particularly squamous cell carcinoma (SCC), has posed a grave challenge to global health due to its high incidence, metastasis, and mortality rates. Despite numerous studies and favorable improvements in the therapeutic strategies over the past few decades, the prognosis of this disease remains dismal. Moreover, several drawbacks are associated with the conventional treatment; including permanent disfigurement and physical impairment that are attributed to surgical intervention, and systemic toxicity that results from aggressive radio- or chemotherapies, which impacts patients’ prognosis and post-treatment quality of life. The highly vascularized, non-keratinized oral mucosa appears as a potential route for cytotoxic drug administration in treating oral cancer. It acts as a non-invasive portal for drug entry targeting the local oral lesions of the early stages of cancer and the systemic metastasis sites of advanced cancer. The absorption of the poorly aqueous-soluble anti-cancer drugs can be enhanced due to the increased permeability of the ulcerous mucosa lining in the disease state and by bypassing the hepatic first-pass metabolism. However, some challenges in oral transmucosal drug delivery include the drugs’ taste, the limited surface area of the membrane lining the oral cavity, and flushing and enzymatic degradation by saliva. Therefore, mucoadhesive nanocarriers have emerged as promising platforms for controlled, targeted drug delivery in the oral cavity. The surface functionalization of nanocarriers with various moieties allows for drug targeting, bioavailability enhancement, and biodistribution at the site of action, while the mucoadhesive feature prolongs the drug’s residence time for preferential accumulation to optimize the therapeutic effect and reduce systemic toxicity. This review has been focused to highlight the potential of various nanocarriers (e.g., nanoparticles, nanoemulsions, nanocapsules, and liposomes) in conferring targeting, solubility and bioavailability enhancement of actives and mucoadhesive properties as novel tumor-targeted drug delivery approaches in oral cancer treatment.

The Articulate Canker-Aphthous Ulcer

Aphthous ulcer occurs as a frequent, idiopathic, painful, singular, multiple or reoccurring oral ulceration. Of obscure aetiology, oral trauma, stress, anxiety, diverse systemic diseases as coeliac disease, Crohn’s disease, Behçet’s syndrome, reactive arthritis or infection with human immune deficiency virus (HIV), drugs such NSAIDs, β-blockers, angiotensin converting enzyme (ACE) inhibitors, deficiencies of vitamins and trace elements as zinc, iron, B12, folate or sensitivity to food and chemicals may engender the ulcer. Contingent to magnitude, aphthous ulcer is subcategorized into minor ulcer, major ulcer or herpetiform ulcer. Aphthous ulcer manifests upon non-keratinized oral mucosa as a well circumscribed, centric, necrotic ulcer circumscribed by a grey, fibrinous exudate and an erythematous halo. The ulcer requires a segregation from contact dermatitis, lichen planus, oral carcinoma, infection with herpes simplex virus (HSV), various drug induced lesions or autoimmune diseases. Aphthous ulcer can be evaluated with clinical examination, complete blood count with nutritional deficiencies of iron, folate or vitamin B12, neutropenia, serum anti-endomysial antibodies and transglutaminase (tTg-IgA) for coeliac disease and investigations for HIV. Cogent therapeutic options are local anaesthetics, coating or occlusive agents as bismuth subsalicylate, sucralfate, 2-octyl cyanoacrylate, bio-adherent emollient pastes, oral antiseptics as chlorhexidine gluconate, hydrogen peroxide, antiinflammatory agents as glucocorticoids, metalloprotease inhibitors, antimicrobials as tetracycline, doxycycline, minocycline, honey, immunomodulatory agents as amlexanox, colchicine, cyclosporine, cyclophosphamide, dapsone, methotrexate, montelukast, thalidomide or retinoids.

Salivary irisin: potential inflammatory biomarker in recurrent apthous stomatitis patients.

Recurrent Aphthous Stomatitis (RAS) is the most common inflammatory condition of the oral mucosa characterised by recurrent onset of single or multiple painful ulcers mainly affecting the nonkeratinized oral mucosa. RAS mostly occurs in healthy individuals with no associated systemic diseases. Irisin is a newly identified adipomyokine and research has revealed that it has anti-inflammatory effects. The aim of this study was to investigate the significance of salivary irisin levels in patients with recurrent apthous stomatitis (RAS). In this investigation, 80 individuals were evaluated. The patient group included 30 patients diagnosed with RAS and each control group consisted of 25 smoker and non-smoker healthy individuals. Saliva samples were collected and salivary irisin, interleukin-2 (IL-2) and interferon-ɣ (IF-ɣ) levels were determined using enzyme-linked immunosorbent assay (ELISA). IL-2 and IF-ɣ levels in RAS patients were significantly higher than control smoker and non-smoker groups (p=0.0001, p=0.0001, respectively). Irisin level was higher in RAS patients than smoker controls and non-smoker controls. The level of irisin was found as sensitive and specific as IL-2 and more sensitive and specific than IF-ɣ. The salivary levels of pro-inflammatory cytokines IL-2 and IF-ɣ and irisin were higher in RAS group compared to controls. This is the first report evaluating the irisin an adipo-myokine as an inflammatory biomarker in RAS.

Molecular effects of photon irradiation and subsequent aftercare treatment with dexpanthenol-containing ointment or liquid in 3D models of human skin and non-keratinized oral mucosa.

This study aimed to investigate the molecular effects of radiation and subsequent aftercare treatment with dexpanthenol-containing ointment and liquid on established full-thickness 3D skin models depicting acute radiodermatitis and mucositis. To mimic radiomucositis and radiodermatitis, non-keratinized mucous membrane and normal human skin models were irradiated with 5 Gray. Afterwards, models were treated topically every second day with dexpanthenol-containing ointment or liquid in comparison with placebo and untreated controls. On day 7 after irradiation, histological examination showed impairments in irradiated models. In contrast, models treated with dexpanthenol-containing ointment or liquid showed a completely restored epidermal part. While gene expression profiling revealed an induction of genes related to a pro-inflammatory milieu, oxidative stress and an impaired epidermal differentiation after irradiation of the models, aftercare treatment with dexpanthenol-containing ointment or liquid revealed anti-oxidative and anti-inflammatory effects and had a positive effect on epidermal differentiation and structures important for physical and antimicrobial barrier function. Our findings confirm the potential of our established models as in vitro tools for the replacement of pharmacological in vivo studies regarding radiation-induced skin injuries and give indications of the positive effects of dexpanthenol-containing externals after radiation treatments as part of supportive tumor treatment.

Comparison of Virgin Coconut Oil with 5% Amlexanox in Management of Minor Recurrent Aphthous Ulcers - A Randomized Control Trial

Objective: Recurrent Aphthous Ulcer (RAU) is a common (75-80%) painful inflammatory ulcerative disorder of the non-keratinized oral mucosa. Wide range of antiseptics, anti-inflammatory, antibiotics and corticosteroids are available for treatment. Amlexanox is a topical anti-inflammatory and anti-allergic drug used to treat RAS. Recently, there has been increase in interest in use of essential oil and herbal medicine in managing RAU, one such natural product is virgin coconut oil. This study is aimed to determine the efficacy of VCO in management of signs and symptoms of minor recurrent aphthous ulcers. Methodology: 40 patients were included for the study who were randomly divided into two groups. 20 patients in Group A (VCO) and 20 patients in Group B (5%Amlexanox). Primary outcome measured were reduction in ulcer size (in mm) and pain (VAS 1-10). Results: There is high statistical significant difference within the groups in ulcer healing and pain reduction (p=0.00) on 3rd and 5th day. In group A significant reduction in pain was present on the 5th day (p=0.02) and no significant reduction in ulcer size (p=0.083). No adverse effects were reported in either group. Conclusion: VCO could be used as an effective and safe drug in managing the signs and symptoms of RAS. It is edible oil with no known adverse effects and could be a safe therapeutic alternative in children and pregnant women.

Management of recurrent apthous ulcer using Corticosteroids, Local anesthetics and nutritional supplements.

Recurrent Aphthous ulcers are the most common oral lesions among dental patients. The ulcers, which usually occur on the nonkeratinized oral mucosa, can cause considerable pain and may interfere with eating, speaking, and swallowing. Therefore, it is of interest to report data on the management of recurrent aphthous ulcer using corticosteroids, local anesthetics and nutritional supplements. Case sheets of 76 patients who underwent treatment for recurrent aphthous ulcer between June 2019 and March 2020 at the Saveetha Dental College, India were used in this analysis. Data was analyzed using Chi square test at a P value < 0.05 that is statistically significant. Results show that topical anaesthetics in population (49%) were more effective that corticosteroids. Thus, topical anaesthetics are recommended for recurrent aphthous ulcer.

DONOR SITE COMPLICATIONS OF ORAL MUCOSA GRAFT URETHROLPASTY

Background: The use of oral mucosa grafts in urethroplasty involves transplantation of non-keratinized oral mucosa for the repair of urethral strictures. In the last two decades this has emerged as the most widely used substitute tissue in urethral reconstruction. Harvesting of oral mucosal grafts for urethroplasty, however, has certain complications. Objective: This study evaluated the donor site complications associated with oral mucosa graft harvest for anterior urethral reconstruction for stricture. Materials and Patients: This prospective study of 28 consecutive patients presented at the Urology Unit of a University Teaching Hospital with long-segment urethral stricture and underwent oral mucosa graft harvest and substitution urethroplasty. The donor sites were evaluated at 48 hours, at discharge, 1 month and 3 months postoperatively for complications. Results: The patients' mean age in this study was 45.4 (+ 13.2) years with a range of 14-69 years. The mean length of graft was 5.25cm (+ 2.00), range of 1.5cm -11.0 cm. The location of strictures was bulbar urethra in 14 (50%), in 12 (43%), it was present in the penobulbar and 2 (7%) penile urethra. Graft donor sites were buccal in 25 (89.3%) in 2 (7.0%), buccal and labial and in 1 patient (3.5%) was lingual. Donor site complications included pain (32%), bleeding (14%) and peri-oral numbness (3.5%). All were able to eat and drink within 48hrs post-operatively and donor site complications resolved at discharge, and there were no events at follow-up. Conclusion: Harvesting of oral mucosa graft for substitution urethroplasty is safe, but maybe. associated with minimal short- term donor site complications

Type XVIII Collagen Modulates Keratohyalin Granule Formation and Keratinization in Oral Mucosa.

Epithelial keratinization involves complex cellular modifications that provide protection against pathogens and chemical and mechanical injuries. In the oral cavity, keratinized mucosa is also crucial to maintain healthy periodontal or peri-implant tissues. In this study, we investigated the roles of type XVIII collagen, a collagen-glycosaminoglycan featuring an extracellular matrix component present in the basement membrane, in oral mucosal keratinization. Histological analysis of keratinized and non-keratinized oral mucosa showed that type XVIII collagen was highly expressed in keratinized mucosa. Additionally, a 3D culture system using human squamous carcinoma cells (TR146) was used to evaluate and correlate the changes in the expression of type XVIII collagen gene, COL18A1, and epithelial keratinization-related markers, e.g., keratin 1 (KRT1) and 10 (KRT10). The results showed that the increase in COL18A1 expression followed the increase in KRT1 and KRT10 mRNA levels. Additionally, loss-of-function analyses using silencing RNA targeting COL18A1 mRNA and a Col18-knockout (KO) mouse revealed that the absence of type XVIII collagen induces a dramatic decrease in KRT10 expression as well as in the number and size of keratohyalin granules. Together, the results of this study demonstrate the importance of type XVIII collagen in oral mucosal keratinization.

Recurrent Aphthous Stomatitis and Nutritional Deficiencies: Report of Three Cases with Literature Review

Introduction: Recurrent aphthous stomatitis (RAS) is the most common ulcerative disease that affects the non-keratinized oral mucosa. The etiology is still unknown, but several local and systemic factors have been proposed as causal agents. Case description: three patients are reported with RAS associated with nutritional deficiencies, due to dietary restriction diets. The first case, a 19-year-old woman with iron deficiency, reported taking green tea daily and consuming a small amount of carbohydrates, fats and meat. The second case, a 32-year-old man with iron deficiency and vitamin B12 associated with vegan diet, although sometimes if he consumed meat. The third case, man of 50 years, vegan and ex-smoker for a year, presented deficiency of iron, vitamin B12 and folic acid. In all three cases a detailed questioning, clinical examination and complete blood analysis allowed to establish an adequate diagnosis, dental management and referral with a nutritionist, in order to treat the underlying pathology and not only provide a symptomatic treatment of the injuries. Discussion: In the setting of RAS, it is advisable to perform an analysis that includes a blood count, folic acid, iron and vitamin B12, to rule out possible systemic causes and eventually treat them. Clinical management aims to improve patient function and quality of life through topical and systemic therapies; however, it is essential to identify and control the causal factors that contribute; as well as, the exclusion or treatment of the underlying systemic disease.

Prevalence and psychological stress in recurrent aphthous stomatitis among female dental students in Saudi Arabia.

IntroductionRecurrent Aphthous Stomatitis (RAS) is a common oral mucosal disorder which is characterized by recurrent ulcerations mainly confined to non-keratinized oral mucosa. Though the exact etiology is imprecise, stress and anxiety were found to be linked with the onset of RAS. The present study was directed to know the prevalence of RAS among female dental students in King Khalid University, to find out the association between RAS and psychological stress and the effectiveness of Hospital Anxiety and Depression scale (HADS) in finding out the psychological profile of RAS patients.Method122 female dental students of age group 17 to 25 years were selected for the study. Subjects with relevant medical problems and deleterious habits were excluded. A questionnaire comprising general stress related questions and HAD scale were used to assess stress. Those who were giving history of ulcer were diagnosed as RAS based on the clinical features. The questionnaire results were used for statistical analysis and processed.Result14% of the total students were having RAS. 70% could correlate the onset of ulcer with certain specific factors; stress being the major causative agent (91%). In HAD scale, 88% of students were having anxiety and 65% had depression; all patients with depression had anxiety.ConclusionThe prevalence of RAS in female dental students in KKU was around 14%. There is a strong relationship between psychological stress and RAS, as in most of the other studies. HAD scale alone can be used for detecting the psychological factor in RAS.

IL‐17C and its receptor IL‐17RA/IL‐17RE identify human oral epithelial cell as an inflammatory cell in recurrent aphthous ulcer

Recurrent aphthous ulcer (RAU) is an ulcerative disease of non-keratinized oral mucosa. Colon and bronchial epithelial cells produce interleukin-17C (IL-17C) upon stimulation of Toll-like receptor 2 (TLR2), TLR3 and TLR5, which are highly expressed in epithelial cells in RAU lesions. We therefore investigated the eventual presence and function of IL-17C in cultured human oral keratinocytes (HOK) and control biopsies compared to RAU lesions. Expression of IL-17A, IL-17C, IL-17RA and IL-17RE was analysed in cultured HOK cells using quantitative real-time polymerase chain reaction (qRT-PCR). HOK cells were stimulated with IL-17C and analysed for IL-8 and tumour necrosis factor-α (TNF-α) using qRT-PCR. Control mucosa (n = 5) was immunostained for IL-17A, IL-17C, IL-8, TNF-α and mast cell tryptase and compared with RAU lesions (n = 5) using the mean grey scale value. IL-17C, but no IL-17A, mRNA was found in cultured HOK cells. Components of the heterodimeric IL-17RA/IL-17RE receptor for IL-17C were also highly expressed. Stimulation of HOK with IL-17C increased TNF-α mRNA (P = 0.03; IL-8 increase was not statistically significant). HOK in RAU lesions stained intensively for IL-17C compared to controls (P = 0.006). This was associated with increased epithelial immunostaining of TNF-α (P = 0.04) and IL-8 (P = 0.02). Most of the inflammatory cells which stained for IL-17A in control mucosa and RAU lesions were also mast cell tryptase positive. IL-17C is highly expressed in epithelial cells in RAU lesions, where it seems to stimulate oral keratinocytes via IL-17RA/IL-17RE to produce pro-inflammatory cytokines. Human oral epithelial cells are probably important inflammatory cells in RAU.

Tissue-engineered mucosa is a suitable model to quantify the acute biological effects of ionizing radiation

The aim of this study was to evaluate the suitability of tissue-engineered mucosa (TEM) as a model for studying the acute effects of ionizing radiation (IR) on the oral mucosa. TEM and native non-keratinizing oral mucosa (NNOM) were exposed to a single dose of 16.5Gy and harvested at 1, 6, 24, 48, and 72h post-irradiation. DNA damage induced by IR was determined using p53 binding protein 1 (53BP1), and DNA repair was determined using Rad51. Various components of the epithelial layer, basement membrane, and underlying connective tissue were analyzed using immunohistochemistry. The expression of cytokines interleukin-1β (IL-1β) and transforming growth factor beta 1 (TGF-β1) was analyzed using an enzyme-linked immunosorbent assay. The expression of DNA damage protein 53BP1 and repair protein Rad51 were increased post-irradiation. The expression of keratin 19, vimentin, collage type IV, desmoglein 3, and integrins α6 and β4 was altered post-irradiation. Proliferation significantly decreased at 24, 48, and 72h post-irradiation in both NNOM and TEM. IR increased the secretion of IL-1β, whereas TGF-β1 secretion was not altered. All observed IR-induced alterations in TEM were also observed in NNOM. Based on the similar response of TEM and NNOM to IR we consider our TEM construct a suitable model to quantify the acute biological effects of IR.

Feasibility of a porcine oral mucosa equivalent: A preclinical study

Oral tissue engineering aims to treat and fill tissue deficits caused by congenital defects, facial trauma, or malignant lesion surgery, as well as to study the biology of oral mucosa. The Food and Drug Administration (FDA) and the European Medicines Agency (EMA) require a large animal model to evaluate cell-based devices, including tissue-engineered oral mucosa, prior to initiating human clinical studies. Porcine oral mucosa is non-keratinized and resembles that of humans more closely than any other animal in terms of structure and composition; however, there have not been any reports on the reconstruction of a porcine oral mucosa equivalent, probably due to the difficulty to culture porcine fibroblasts. In this study, we demonstrate the feasibility of a 3D porcine oral mucosa equivalent based on a collagen-GAG-chitosan scaffold, as well as reconstructed porcine epithelium by using an amniotic membrane as support, or without any support in form of epithelial cell sheets by using thermoresponsive culture plates. Explants technique was used for the isolation of the porcine fibroblasts and a modified fibroblast medium containing 20% fetal calf serum was used for their culture. The histological and transmission electron microscopic analyses of the resulting porcine oral mucosa models showed the presence of non-keratinized epithelia expressing keratin 13, the major differentiation marker of non-keratinized oral mucosa, in all models, and the presence of newly synthesized collagen fibers in the lamina propria equivalent of the full-thickness model, indicating the functionality of porcine fibroblasts.

Expression of Th1/Th2/Th3/Th17-Related Genes in Recurrent Aphthous Ulcers

The pathogenesis of recurrent aphthous ulceration (RAU) is unknown, although an abnormal immune reaction appears to be involved. RAU may result from oral epithelium damage caused by T cell-mediated immune response. To improve understanding of the role of T cells in RAU, the present study analyzed. the expression of T cell-related genes in oral ulcers from patients with RAU, as well as in healthy non-keratinized oral mucosa from aphthae-free volunteers. Biopsies from RAU patients and healthy individuals were analyzed using Human Th1-Th2-Th3 RT(2) Profiler PCR Array and qRT-PCR that allowed to quantify the transcript levels of 86 genes related to T cell activation. We found that cells present in aphthous ulcers express a characteristic Th1-like gene profile. The majority of genes up-regulated in aphthous lesions such as IFN-γ, TNF, IL-15, IRF1, STAT-1 and STAT-4 were Th1-associated. Th2-realated genes were not overexpressed in RAU tissues, with the exception for CCR3. Th3- and Th17-related gene expression patterns were not demonstrated in RAU. These findings clearly reveal that aphthous ulcer formation is predominantly dependent on the activation of the Th1-type immune response.

Characterization of a Three-Dimensional Mucosal Equivalent: Similarities and Differences with Native Oral Mucosa

The aim of this study was to create and characterize a tissue-engineered mucosal equivalent (TEM) that closely resembles native mucosa. TEM consists of human primary keratinocytes and fibroblasts isolated from biopsies taken from healthy donors and seeded onto a de-epidermized dermis and cultured for 14 days at the air/liquid interface. The structure of TEM was examined and compared with native nonkeratinizing oral mucosa (NNOM). The various components of the newly formed epidermal layer, basement membrane and underlying connective tissue were analyzed using immunohistochemistry. The mucosal substitute presented in this study showed a mature stratified squamous epithelium that was similar to that of native oral mucosa, as demonstrated by K19, desmoglein-3 and involucrin staining. In addition, the expression of basement membrane components collagen type IV, laminin-5 and integrin α6 and β4 in TEM proved to be consistent with native oral mucosa. The expression of PAS, Ki67, K10 and K13, however, appeared to be different in TEM compared to NNOM. Nevertheless, the similarities with native oral mucosa makes TEM a promising tool for studying the biology of mucosal pathologies such as oral mucositis or fibrosis as well as the development of new therapies.