Oral Mucosal Epithelium Research Articles

Modification of radiation-induced oral mucositis (mouse) by adult stem cell therapy: single-dose irradiation.

Early oral mucositis occurs in response to accidental upper partial body exposure as well as to radiotherapy in the head-and-neck region. This study was initiated to define the potential of mobilization of endogenous bone marrow (BM) stem cells by rHuG-CSF or of bone marrow transplantation (BMT) to reduce the effect of single-dose irradiation on mouse oral epithelium. A 3 × 3 mm(2) area of the lower tongue surface of mice was irradiated with graded single doses (day 0). Mucosal ulceration was used as the endpoint for dose-response analyses. Stem cells were mobilized by rHuG-CSF (8 times/4 days), timed to achieve a maximum of circulating stem cells on days 0, +1, +4, +8 or +10. Alternatively, syngeneic BM was transplanted on these days. The ED(50) (dose at which ulceration is expected in 50 % of the animals) for irradiation alone was 11.9 ± 3.4 Gy. Mobilization of stem cells with a maximum of circulating stem cells on days +4, +8 or +10 significantly increased the ED(50) to 25.5 ± 10.1, 23.5 ± 10.1 and 26.5 ± 13.0 Gy. In contrast, a maximum of circulating stem cells on day 0 or day +1 had no effect. BMT did not result in a significant change in isoeffective doses in any of the protocols. In conclusion, the response of oral mucosal epithelium to a single-radiation exposure can be significantly reduced by post-exposure mobilization, but not by transplantation, of BM stem cells.

Successful culture and characterisation of ex vivo expanded human autologous oral mucosa epithelium using a feeder- and animal product- free method for the treatment of total bilateral limbal stem cell deficiency

Successful culture and characterisation of ex vivo expanded human autologous oral mucosa epithelium using a feeder- and animal product- free method for the treatment of total bilateral limbal stem cell deficiency

HIV-Associated Disruption of Tight and Adherens Junctions of Oral Epithelial Cells Facilitates HSV-1 Infection and Spread

Herpes simplex virus (HSV) types 1 and 2 are the most common opportunistic infections in HIV/AIDS. In these immunocompromised individuals, HSV-1 reactivates and replicates in oral epithelium, leading to oral disorders such as ulcers, gingivitis, and necrotic lesions. Although the increased risk of HSV infection may be mediated in part by HIV-induced immune dysfunction, direct or indirect interactions of HIV and HSV at the molecular level may also play a role. In this report we show that prolonged interaction of the HIV proteins tat and gp120 and cell-free HIV virions with polarized oral epithelial cells leads to disruption of tight and adherens junctions of epithelial cells through the mitogen-activated protein kinase signaling pathway. HIV-induced disruption of oral epithelial junctions facilitates HSV-1 paracellular spread between the epithelial cells. Furthermore, HIV-associated disruption of adherens junctions exposes sequestered nectin-1, an adhesion protein and critical receptor for HSV envelope glycoprotein D (gD). Exposure of nectin-1 facilitates binding of HSV-1 gD, which substantially increases HSV-1 infection of epithelial cells with disrupted junctions over that of cells with intact junctions. Exposed nectin-1 from disrupted adherens junctions also increases the cell-to-cell spread of HSV-1 from infected to uninfected oral epithelial cells. Antibodies to nectin-1 and HSV-1 gD substantially reduce HSV-1 infection and cell-to-cell spread, indicating that HIV-promoted HSV infection and spread are mediated by the interaction of HSV gD with HIV-exposed nectin-1. Our data suggest that HIV-associated disruption of oral epithelial junctions may potentiate HSV-1 infection and its paracellular and cell-to-cell spread within the oral mucosal epithelium. This could be one of the possible mechanisms of rapid development of HSV-associated oral lesions in HIV-infected individuals.

Inhibition of Caspases Protects Mice from Radiation-induced Oral Mucositis and Abolishes the Cleavage of RNA-binding Protein HuR

The oral mucosal epithelium is typically insulted during chemotherapy and ionizing radiation (IR) therapy and disposed to mucositis, which creates painful inflammation and ulceration in the oral cavity. Oral mucositis alters gene expression patterns, inhibits cellular growth, and initiates cell death in the oral epithelial compartments. Such alterations are governed by several different factors, including transcription factors, RNA-binding proteins, and microRNAs. IR-induced post-transcriptional regulation of RNA-binding proteins exists but is poorly studied in clinically relevant settings. We herein report that the RNA-binding protein human antigen R (HuR) undergoes cleavage modification by caspase-3 following IR-induced oral mucositis and subsequently promotes the expression of the pro-apoptotic factor BAX (Bcl-2-associated X protein), as well as cell death. Further analyses revealed that the HuR cleavage product-1 (HuR-CP1) directly associates and stabilizes the BAX mRNA and concurrently activates the apoptotic pathway. On the other hand, a noncleavable isoform of HuR promotes the clonogenic capacity of primary oral keratinocytes and decreases the effect of IR-induced cell death. Additionally, specific inhibition of caspase-3 by a compound, NSC321205, increases the clonogenic capacity of primary oral keratinocytes and causes increased basal layer cellularity, thickened mucosa, and elevated epithelial cell growth in the tongues of mice with oral mucositis. This protective effect of NSC321205 is mediated by a decrease in caspase-3 activity and the consequent inhibition of HuR cleavage, which reduces the expression of BAX in mice with IR-induced oral mucositis. Thus, we have identified a new molecular mechanism of HuR in the regulation of mRNA turnover and apoptosis in oral mucositis, and our data suggest that blocking the cleavage of HuR enhances cellular growth in the oral epithelial compartment.

ORAL LİKEN PLANUS: DİRENÇLİ BİR OLGUNUN TEDAVİSİ* Oral Lichen Planus: Treatment of a Refractory Case (Case Report)

Oral lichen planus (OLP) is a relatively common, chronic inflammatory disease that often affects the stratified squamous epithelia of oral mucosa. The disease is affecting approximately 1-2% of the population. It is seen mostly in the third to sixth decades of life, and is twice as common in women than men. OLP’s pathogenesis of immune system is thought to have played a role in the etiology is not known. A 25-year-old male patient was referred our clinic due to white lesions on his lower lip. Similar lesions were detected on his tongue, retromolar region, gingiva as well as various parts of oral mucosa result of clinical examiation. Biopsies were taken for direct immunofluorescense (DIF) and histopathological examinations. As a result of bipsies OLP were diagnosed. In this paper the treatment of our patient and the clinical changes of patient with the treatment will be presented.

Unusual Atypical Epithelial Proliferation of Unknown Biologic Behavior in a 5-Year-Old Boy

A 5-year-old boy presented clinically with a subgingival supraperiosteal expansile mass associated with the mandibular anterior central incisors. There was no obvious clinical intraosseous involvement. The oral mucosal epithelium did not reveal any clinical changes suggestive of a process originating from the surface. Histopathologic evaluation revealed soft tissue fragments that were surfaced or lined by hyperkeratinizing and acanthotic stratified squamous epithelium exhibiting cytologic variations that include irregular rete pegs, loss of polarity, individual cell keratinization, increased nuclear/cytoplasmic ratio, and prominent nucleoli.

This issue ofActa, printed and electronic

The cover image is a schematic drawing of a retinal implant system for the blind. This is a described in an article by Velikay-Parel from Austria and Germany in the electronic part of this Issue of ACTA. Andrew and associates in Australia review inflammatory diseases in the orbit and their pathophysiology. Bjerrum et al. in Copenhagen found significantly higher risk of postoperative endophthalmitis after cataract surgery at a few private hospitals and clinics in Denmark compared with public hospitals. Hietala et al. in Helsinki and Australia found that individuals with higher age of onset of type 1 diabetes are more likely to develop macular oedema. Bertelsen et al. in Norway and UK found that microalbuminuria may be a useful risk predictor for diabetic retinopathy. van Dijk et al. in the Netherlands and USA found considerable variability in photocoagulation treatment plans influenced among other things by the assessment with slit lamp biomicroscopy versus OCT. Kofoed et al. in Copenhagen found abnormal cone function to correlate with carotid artery stenosis and reduced perfusion pressure. Vandewalle et al. Belgium and Iceland found that topical phenylephrine and tropicamide did not influence retinal oxygen saturation measurements or retinal vessel diameter. Ernest et al. in the Netherlands found a considerable prevalence of visual impairment in patients with glaucoma at the end of their life but the visual impairment was in many cases caused by other eye diseases. Ilmarinen et al. in Finland cultivated oral mucosal epithelium and treated severe ocular surface injuries with limbal stem cell deficiency. Konradsen and Zetterström in Stockholm found that flat cornea in Marfan syndrome reduces the myopic consequence of long axial length. Hirayama et al. in Japan describe symptomatic relief of ocular dryness and improved tear stability with moist cool air devices in offices. Pathak et al. in Oslo contribute a case series of patients who receive transplantation of ex vivo-expanded limbal epithelial cells with good results. González-López et al. in Spain found that only one temporal artery biopsy in four is positive in patients suspected of giant cell arteritis and suggest ways of improving this ratio. Næser et al. in Denmark present a case series of patients with Wegener's granulomatosis who underwent dacryocystorhinostomy. Peter Kristian Rasmussen presents his thesis on diffuse large B-cell and mantle cell lymphoma of the ocular adnexal region and lymphoma of the lachrymal gland. The following articles are published electronically only and are accessible on www.actaophthalmologica.com Lamoureux et al. in Australia and Singapore found good reliability and reproducibility with retinal oxygen saturation measurements. Velikay-Parel et al. in Austria and Germany tested an investigational epiretinal implant in a patient with retinitis pigmentosa. The device was found to be safe and stable. Koinzer et al. in Germany describe differences between OCT images and histology of photocoagulation lesions in retina. Hoffmann et al. in Germany, Italy and Portugal use Heidelberg retina tomography to study optic disc changes in people with ocular hypertension. They found strong associations between various structural optic nerve parameters. Saenz-Frances et al. in Spain find that peripheral corneal thickness may be important in intraocular pressure measurements and glaucoma in addition to central corneal thickness. Garcia-Martin et al. in Spain documented retinal nerve fibre layer loss in patients with multiple sclerosis, using OCT technology. Januschowski et al. in Germany used a microsensor to measure the wearing time of glasses and ocular patches in patients with amblyopia. Lara et al. in Italy examined gene mutations and immunoreactivity in conjunctiva melanomas. Montero et al. in Spain examined intravitreal drug dispersion with different size needles. Maschi-Cayla et al. in France used proton beam to treat conjunctival melanomas. Lesiewska-Junk et al. in Poland looked for oxidative stress markers on erythrocytes in patients with pseudoexfoliation. Tassignon et al. in Belgium used Scheimpflug camera to examine location of phakic intraocular lenses. Jakob and Van Calster in Belgium associate skin tattoos with uveitis. Brunner and Binder in Austria surgically excised retinal embolae. Purtskhvanidze et al. in Germany report open globe injuries from rotating wire brushes. Zhou et al. in China and Germany describe a series of bilateral retinal detachments. I wish you Merry Christmas and a Happy New Year and hope that you enjoy reading ACTA during the holidays.

Povidone-iodine-induced cell death in cultured human epithelial HeLa cells and rat oral mucosal tissue

Although povidone-iodine (PVP-I) has been used as a gargle since 1956, its effectiveness and material safety have been remained controversial. The aim of this study was to investigate the toxicity of PVP-I to epithelial cells in a concentration range significantly lower than that used clinically. Study design was in vitro laboratory investigations and in vivo histological and immunologic analysis. We examined the effects of PVP-I at concentrations of 1 × 10−2 to 1 × 103 μM and 1 × 10−4 to 1 × 10 μM on HeLa cells as a model of epithelial cells and rat oral mucosa, respectively, after 1 or 2 days of exposure. Annexin V/FLUOS was used to distinguish live, apoptotic and necrotic cells. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method was also used to observe whether apoptotic epithelial cells exist in rat oral mucosa after 1 day of exposure of PVP-I. HeLa cells developed concentration-dependent cytotoxicity, and epithelium of rat oral mucosa was thinned in a concentration-dependent manner. HeLa cell apoptosis increased after 1 × 100 μM of PVP-I exposure for 2 days. In the TUNEL method, many apoptotic epithelial cells were observed in the rat oral mucosa after 1 day of exposure to diluted 1 × 10−2 μM of PVP-I, but minimal apoptotic epithelial cells were observed using 1 × 10−3 μM of PVP-I. Our findings suggest that exposure to PVP-I, of which concentrations are even lower than those used clinically, causes toxicity in epithelial cells. This knowledge would help us better understand the risk of the use of PVP-I against mucosa.

Vocal Fold Cover Layer with a Tissue‐Engineered Structure Containing Epithelium and Fibroblast of Oral Mucosa

Objectives: A potential treatment option for severe vocal fold scarring is to replace the vocal fold cover layer with a tissue-engineered structure containing autologous cells. The aim of this study is to develop a three-dimensional cell-populated matrix resembling the vocal fold layers of epithelium and lamina propria from autologous oral mucosa. Methods: A 3-by-3-mm specimen of canine buccal mucosa was harvested and divided into epithelium and submucosa. Epithelial cells from the epithelium and fibroblasts from the submucosa were isolated and separately cultured. After the culturing for 2 weeks, the epithelial cells were seeded on mesh type oriented collagen gels containing the fibroblasts throughout a 2-week-culture period. The morphological characteristics of the cultured tissue were observed with immunohistochemical staining and transmission electron microscopy. Normal canine vocal fold and buccal mucosa were used as positive controls. Results: We successfully fabricated a vocal fold cover layer with a tissue-engineered structure closely resembling the normal vocal fold layers of epithelium and lamina propria. The epithelium had three to five cell layers and did not resemble the original oral mucosa. The epithelial cells were immunostained with anti-keratin 3 antibodies, anti-b1 integrin antibodies, and anti-p63 antibodies. The fibroblasts in the collagen gels were immunostained with anti-vimentin antibodies. Electron microscopy revealed developed microvilli on the apical surface of the epithelial cells. Conclusions: The tissue-engineered vocal fold cover layer from autologous oral mucosa has the possibility to reconstruct the vocal fold surface and to restore voice in patients with severe vocal fold scarring.

Amniotic membrane as a tissue engineering substrate

AbstractAmniotic membrane (AM) is commonly used for cell culture and transplantation onto the ocular surface. AM serves the dual purpose of culture substrate and scaffold thus reducing cell manipulation. Crucially AM is believed to promote the retention of stem cell phenotypes essential for the long term restoration of functional tissue. As potential cellular therapies for corneal regeneration are being developed many of them continue to use AM. Its widespread usage in ophthalmology and extensive list of wound healing attributes has made AM a popular choice. Amniotic membrane is being used as a carrier for innovative research into the transplantation of non‐corneal cell types onto ocular surface burn models including mesenchymal stem cells and oral mucosal epithelium. A lack of standardisation in the preparation of amniotic membrane can cause considerable variation and some methods of preparation may reduce or enhance certain attributes. Various methods of processing including cross‐linking, denuding and freeze drying have sought to enhance amniotic membrane for tissue engineering purposes with varied levels of success.

Transplantation of cultured oral mucosal epithelium

AbstractAbstract not provided

Neutral endopeptidase regulates neurogenic inflammatory responses induced by stimulation of human oral keratinocytes with bacterial lipopolysaccharide and nicotine

Neutral endopeptidase (NEP) is present on various epithelial cells and inactivates numerous physiologically active peptides. Neutral endopeptidase may regulate proinflammatory signals in oral mucosal epithelium. However, the function of NEP in oral mucosal epithelium is unknown. The present study investigated the action of NEP upon proinflammatory signals on human oral keratinocytes and the influence of endothelin-converting enzyme (ECE)-1, an enzyme similar to NEP, on the functions of NEP. Oral keratinocytes were cultured in medium containing inflammatory inducers [lipopolysaccharide (LPS) and nicotine], NEP inhibitors, and ECE-1/NEP inhibitors, either alone or in combination. The concentrations of substance P (SP) and interleukin-1β (IL-1β) were measured in the supernatant. Additionally, the concentrations of SP and IL-1β were measured in the supernatant of cells incubated with LPS or nicotine after transfection with NEP small interfering RNA (siRNA). The concentrations of SP and IL-1β were significantly increased in cells incubated with NEP inhibitors and, to a lesser extent, in cells incubated with ECE-1/NEP inhibitors, compared with controls (cells incubated with LPS or nicotine alone). The concentrations of SP and IL-1β in cells transfected with NEP siRNA were significantly augmented compared with controls. In conclusion, the present study demonstrated that NEP down-regulated the levels of SP and IL-1β produced from human oral keratinocytes, although ECE-1 may be partly related to the down-regulation.

In vitro bioaccessibility, bioavailability and plasma protein interaction of polyphenols from Annurca apple (M. pumila Miller cv Annurca)

The in vitro bioaccessibility, bioavailability and plasma protein interaction of polyphenols from Annurca apple and other conventional cultivars were evaluated. Salivary digestion concentrated into the medium 27–35% of native apple polyphenols, suggesting the potential bioavailability through the oral mucosal epithelium of significant amounts of bioactive compounds that could be gastric sensitive and/or poorly absorbed in the intestine. Annurca flesh revealed the highest content and provided the best intestinal bioaccessibility and bioavailability of oligomeric procyanidins among all of the apple peel and flesh tested. Since 49.4% of native procyanidins were not absorbed, they are expected to accumulate in the intestinal lumen where a potential inhibition capacity of cellular cholesterol uptake could be assumed. The permeated procyanidins (6.7% of their native pattern, 12.0% of intestinal procyanidins) significantly bound (58.7%) to plasma HDLs, suggesting a major role in cholesterol metabolism. Our results would indicate Annurca apple and its potential nutraceuticals as effective in the regulation of plasma cholesterol levels.

Research progress in the radioprotective effect of the canonical Wnt pathway.

Irradiation from diverse sources is ubiquitous and closely associated with human activities. Radiation therapy (RT), an important component of multiple radiation origins, is a common therapeutic modality for cancer. More importantly, RT provides significant contribution to oncotherapy by killing tumor cells. However, during the course of therapy, irradiation of normal tissues can result in a wide range of side effects, including self-limited acute toxicities, mild chronic symptoms, or severe organ dysfunction. Although numerous promising radioprotective agents have emerged, only a few have successfully entered the market because of various limitations. At present, the widely accepted hypothesis for protection against radiation-caused injury involves the Wnt canonical pathway. Activating the Wnt/β-catenin signaling pathway may protect the salivary gland, oral mucosa, and gastrointestinal epithelium from radiation damage. The underlying mechanisms include inhibiting apoptosis and preserving normal tissue functions. However, aberrant Wnt signaling underlies a wide range of pathologies in humans, and its various components contribute to cancer. Moreover, studies have suggested that Wnt/β-catenin signaling may lead to radioresistance of cancer stem cell. These facts markedly complicate any definition of the exact function of the Wnt pathway.

Abstract 112: Transcriptomic changes in the oral mucosal epithelium reflect the physiologic response to indoor burning of solid fuels.

Abstract RATIONALE: Human exposure to indoor smoke emissions from the domestic burning of solid fuels (e.g. coal, wood, plant materials) is a major cause of morbidity and mortality that affects nearly half of the world's population. While epidemiologic studies on the health impact of indoor air pollution (IAP) have yielded valuable insights from the use of various exposure assessments (e.g. personal and area air sampling, urinary metabolites), there is a need to connect these exposure measures to biomarkers of the host's physiologic response to exposure. We have previously shown that gene-expression (GE) profiles in the upper airway epithelium are affected by tobacco smoke. Thus, we sought to determine whether transcriptomic changes in the oral mucosal epithelium might also capture physiologic responses to IAP from the burning of solid fuels. METHODS: Buccal mucosa epithelial cell scrapings were collected from healthy, non-smoking female subjects in rural Xuanwei, China, where female lung cancer rates are among the highest in the world. Benzo(a)pyrene (BaP) exposure levels from indoor burning of solid fuels (primarily coal) for cooking and heating were measured by personal in-home air monitoring. RNA from 18 samples was extracted and processed onto Affymetrix Gene 1.0 ST arrays. Student's t-test and DAVID were used to identify and characterize genes that vary between relatively high levels of BaP exposure (n=8; BaP 99.0 +/- 45.9) and low (n=10; BaP 16.2 +/- 6.1) exposure. Using GSEA, results were compared to independent airway epithelial GE profiles that distinguish current smokers from never smokers and bronchial GE profiles in subjects with and without lung cancer. RESULTS: We identified 227 genes that were differentially expressed between subjects with high and low BaP exposure (p<0.01). Genes elevated with high BaP exposure were enriched for genes involved in the activation of apoptosis and the Toll-Like Receptor Signaling pathway. Genes that we have previously shown to have altered expression in the bronchial, buccal, and nasal epithelium of current smokers relative to never smokers were enriched among the genes associated with BaP exposure (GSEA; q<0.01). There was also a significant enrichment for bronchial epithelial airway genes that were altered in subjects with and without lung cancer in a previous report (GSEA; q<0.01). CONCLUSION: Buccal epithelial GE is affected by BaP exposure in a population that uses coal and other solid fuels for indoor cooking and heating among healthy women in Xuanwei, China. Solid fuel emissions may elicit some of the same transcriptomic responses as cigarette smoke and lung cancer. This demonstrates the feasibility of using non-invasively collected buccal GE profiling to assess physiologic responses to other inhaled toxins such as coal smoke in population-based studies. Citation Format: Teresa W. Wang, Qing Lan, Bozena Krystyna, Nathaniel Rothman, Roberta Florido, Wei Hu, Katrina Steiling, Gang Liu, Ji Xiao, Yuriy Alekseyev, Jun Xu, Fusheng Wei, H. Dean Hosgood, Boris Reiss, George Downward, Marc Lenburg, Roel Vermeulen, Avrum Spira. Transcriptomic changes in the oral mucosal epithelium reflect the physiologic response to indoor burning of solid fuels. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 112. doi:10.1158/1538-7445.AM2013-112

Periodontal disease and gene‐expression levels of metalloendopeptidases in human buccal mucosal epithelium

Endopeptidases, such as neutral endopeptidase (NEP), endothelin-converting enzyme-1 (ECE-1) and a disintegrin and metalloprotease 17 (ADAM17), are believed to have various important roles in oral mucosal and epidermal tissue for the regulation of defensive biological responses in the oral cavity, and their expression and activity are influenced by various factors, including oral diseases. However, knowledge concerning these endopeptidases in the oral cavity has been minimal until now. This study focused on three metalloendopeptidases - NEP, ECE-1 and ADAM17 - in the oral buccal mucosal epithelium of patients with periodontal diseases and investigated the relationship between their gene-expression levels and periodontal disease. The levels of expression of NEP, ECE-1 and ADAM17 mRNAs in tissue samples collected from the oral buccal mucosal epithelium of 61 patients were investigated by relative quantification using real-time RT-PCR analysis. information on oral and systemic health was obtained from the clinical record of each patient. Among the three groups, classified based on the diagnosis of periodontal diseases (healthy/gingivitis, early periodontitis and moderate/advanced periodontitis), the relative expression level of NEP mRNA was significantly increased in the early periodontitis group and in the moderate/advanced periodontitis group compared with that in the healthy/gingivitis group. Moreover, the relative expression levels of ECE1 and ADAM17 mRNAs were significantly increased in the moderate/advanced periodontitis group compared with those in the healthy/gingivitis group. The correlation coefficients between the mean relative expression levels of NEP and ECE1 mRNAs, NEP and ADAM17 mRNAs, and ECE1 and ADAM17 mRNAs were r=0.758, r=0.707 and r=0.934, respectively (p<0.001). Furthermore, among the oral-related factors, there was a significant correlation between the number of sites with probing pocket depths of more than 4mm and of more than 6mm and the relative expression levels of NEP, ECE1 and ADAM17 mRNAs. In stepwise logistic regression models, high relative expression levels of ECE1 and ADAM17 mRNAs were significantly associated with moderate/advanced periodontitis. The present study suggests that the severity of periodontal disease may be associated with the expression of metalloendopeptidase genes, including NEP, ECE1 and ADAM17, in the buccal mucosal epithelium.

Expression of activation-induced cytidine deaminase in oral epithelial dysplasia and oral squamous cell carcinoma

Oral epithelial dysplasia is thought to be a precursor state of carcinogenesis and may harbor gene alterations. Recently, it was reported that gene editing enzyme, activation-induced cytidine deaminase (AID), is expressed in precursor and cancer epithelial cells during carcinogenesis associated with chronic inflammation/infection and that this enzyme induces mutation of tumor-suppressor genes. Thus, AID may have a role in carcinogenesis via oral epithelial dysplasia. In this study, we classified oral mucosal epithelium exhibiting epithelial dysplasia as squamous intraepithelial neoplasia (SIN) grades 1-3, according to the 2005 World Health Organization classification, and used immunohistochemical techniques to examine AID expression in oral mucosal epithelium exhibiting SIN and oral cancer tissues. AID was observed in prickle cells in oral mucosal epithelium with epithelial dysplasia and in oral cancer cells. Additionally, to investigate the mechanism of AID expression and its role in cancer progression, we incubated the oral cancer cell line HSC-2 with inflammatory cytokines. In the HSC-2 cell line, AID expression was enhanced by TNF-α via NF-κB activation and promoted expression of N-cadherin by regulating Snail expression. These findings suggest that AID has a role in the development of oral epithelial dysplasia and promotes progression of oral cancer.

Ectopically Expressed IBP Promotes Cell Proliferation in Oral Squamous Cell Carcinoma

IFN regulatory factor 4 binding protein (IBP) has been shown to play an important role in the progression of malignant tumors such as breast cancer cells, but its function in oral squamous cell carcinoma (OSCC) remains unclear. We found that IBP ectopically expressed in some OSCC specimens but not in normal oral mucosa epithelium tissues. IBP expression was significantly correlated with tumor size, differentiation, clinical stage, and distant metastasis. Furthermore, IBP markedly promoted OSCC cell proliferation, shortened the G1 interval in the cell cycle, and increased cyclin D1 expression. These findings suggest that IBP may be a potential therapeutic target for OSCC.

Towards a defined, serum- and feeder-free culture of stratified human oral mucosal epithelium for ocular surface reconstruction

Ocular surface reconstruction with cultivated oral mucosal epithelial transplantation technique is a viable treatment option for severe ocular surface injuries and diseases with limbal stem cell deficiency. Currently, this technique is based on utilization of xenogenic, allogenic or undefined components such as murine 3T3 feeders, serum and amniotic membrane. In this study, we aimed to find a more defined culture method to generate stratified human oral mucosal epithelium. In this study, we have examined the formation of stratified cell sheets from human oral mucosal epithelial cells under serum-free culture environment both in the absence and presence of fibroblast-conditioned culture medium and elevated epidermal growth factor (EGF) concentration. In all examined culture conditions, the cultivated oral epithelial cells formed a stratified tissue, which was positive for keratins K3/12, K4 and K13. The tissue-engineered oral epithelia also expressed proliferation and progenitor markers Ki67 and p63 in the basal layer of the cell sheets, suggesting that the epithelia still had regenerative capacity. The cultures presented expression of tight junction proteins ZO-1 and occludin and high transepithelial electrical resistance values. In this culture method, we have been able to produce stratified cell sheets successfully without serum, conditioning of the medium or increased EGF concentration. We provide a novel protocol to produce tight multi-layered epithelium with proliferative potential, which can be easily adapted for cultivated oral mucosal epithelial transplantation.

Oberflächenrekonstruktion bei Limbusstammzellinsuffizienz

Various ocular surface diseases are caused by loss of corneal epithelial stem cells or dysfunction of the limbal stem cell niche. Besides conventional transplantation of autologous or allogenic limbal tissue, recent advances in tissue engineering have led to the development of new culture and expansion techniques of human limbal stem and progenitor cells (LSPC) as a new strategy to successfully treat limbal stem cell deficiency (LSCD). From a small autologous limbal biopsy with a limited amount of LSPC an epithelium ready for transplantation is achieved. Autologous grafting of cultured limbal epithelium led in most of the treated cases to a successful reconstruction of the corneal surface. Alternative methods which have recently been introduced to treat LSCD use other stem cell sources including the transplantation of oral mucosal epithelium. In this article the challenges and controversies associated with these stem cell culture techniques for ocular surface reconstruction are reviewed.