Oral lichen planus: an immunohistochemical study of heat shock proteins (HSPs) and cytokeratins (CKs) and a unifying hypothesis of pathogenesis

Differential genotypes of TNF-α and IL-10 for immunological diagnosis in discoid lupus erythematosus and oral lichen planus: A narrative review

Discoid lupus erythematosus and oral lichen planus are chronic systemic immune system-mediated diseases with unclear etiology and pathogenesis. The oral mucosa is the common primary site of pathogenesis in both, whereby innate and adaptive immunity and inflammation play crucial roles. The clinical manifestations of discoid lupus erythematosus on the oral mucosa are very similar to those of oral lichen planus; therefore, its oral lesion is classified under oral lichenoid lesions. In practice, the differential diagnosis of discoid lupus erythematosus and oral lichen planus has always relied on the clinical manifestations, with histopathological examination as an auxiliary diagnostic tool. However, the close resemblance of the clinical manifestations and histopathology proves challenging for accurate differential diagnosis and further treatment. In most cases, dentists and pathologists fail to distinguish between the conditions during the early stages of the lesions. It should be noted that both are considered to be precancerous conditions, highlighting the significance of early diagnosis and treatment. In the context of unknown etiology and pathogenesis, we suggest a serological and genetic diagnostic method based on TNF-α and IL-10. These are the two most common cytokines produced by the innate and adaptive immune systems and they play a fundamental role in maintaining immune homeostasis and modulating inflammation. The prominent variability in their expression levels and gene polymorphism typing in different lesions compensates for the low specificity of current conventional diagnostic protocols. This new diagnostic scheme, starting from the immunity and inflammation of the oral mucosa, enables simultaneous comparison of discoid lupus erythematosus and oral lichen planus. With relevant supportive evidence, this information can enhance physicians’ understanding of the two diseases, contribute to precision medicine, and aid in prevention of precancerous conditions.

Evaluation of the Altered Tissue Expression of HSP60 and HSP70 Genes in Oral and Cutaneous Lichen Planus Compared to Normal Healthy Tissues

Background:

Recent highlights have investigated the possible roles of molecular chaperons like heat shock proteins (HSPs) into Lichen Planus (LP)-onset and pathogenesis. This study for the first, determine the expression of both HSP60 and HSP70 genes in cutaneous LP (CLP) and oral LP (OLP) lesions compared to normal healthy cases and between different subtypes of OLP lesions by real-time (RT)-PCR.

Materials and Methods:

Paraffin blocks of LP lesions including 56 OLP and 56 CLP samples were selected from theMashhad University of Medical sciences, Mashhad, Iran. Also 56 biopsy samples of healthy normal participants were selected. The demographic and clinical characteristics were extracted from their medical records. The expression of HSP60 and HPS70 genes were evaluated using the real-time RT-PCR method.

Results:

The comparison of the expression of HSP60 and HSP70 genes among the patients with CLP and OLP showed a significant overexpression of HSP60 and HSP70 genes in both groups compared to the normal participants (P = 0.001). The expression of HSP60 and HSP70 genes was high in both the groups of CLP and OLP patients, but the amount was not significantly different between the two groups. Comparing the two mucosal subgroups of OLP lesions (non-erosive and erosive) showed that the expression of the HSP60 and HSP70 in erosive subtypes of OLP was significantly higher than the non-erosive subtypes of OLP (P = 0.001).

Conclusion:

Regarding the overexpression of HSP60 and HSP70 in the LP lesions compared to healthy biopsies, we conclude that HSP60 and HSP70 could have key roles in the etiopathogenesis of the OLP and CLP lesions. The overexpression of both HSP60 and HSP70 in the erosive OLP group compared to the non-erosive OLP group emphasized the possible roles of HSPs in the pathogenesis and premalignant changes of OLP lesions.

Evaluation of exposure to environmental stressors on heat-shock protein 70 expression in normal oral keratinocyte cells

Objectives

This study aimed to investigate the effect of cortisol, estrogen, and nicotine on heat shock protein 70 (HSP70) expressions at the level of normal oral mucosa keratinocyte cells.

Methods

In this in vitro study, keratinocytes were derived from rat oral cavity and cultured. Stressors were applied, including three groups, group 1: estrogen to simulate the postmenopausal state; group 2: cortisol to simulate psychological stress situation; group 3: nicotine to simulate smoking state. To determine the exact nature of keratinocyte cells, two surface markers, cytokeratin 18 and cytokeratin 14 were examined using the flow cytometry method. Then, the immunocytochemistry technique with three repetitions in each group was used to evaluate the HSP70 expression before and after applying the stressor.

Results

HSP70 expressions in the three stressor groups (estrogen, cortisol, and nicotine) were significantly lower than in the control group (p = 0.0001). The HSPs expression difference between cortisol and nicotine was statistically significant (p = 0.0001). Based on the results of MTT analysis, the mean cell viability of oral mucosal keratinocytes in all three intervention groups decreased compared to the control group. In the cortisol and nicotine groups, cell death was significantly higher than in the control group. In the estrogen group, cell death was significantly lower than in the nicotine group (p > 0.05).

Conclusions

The specific concentrations of cortisol, estrogen, and nicotine as stressors can effectively reduce the expression of HSP70 in normal oral mucosal keratinocytes. These phenomena can be effective in cell viability and the development of oral lichen planus.

Overexpression and extra-mitochondrial localization of the chaperonin Hsp60 in ameloblastoma

OBJECTIVES

Ameloblastoma is an odontogenic neoplasm of the mandible and maxilla with various histological types and subtypes. It has been reported that some ameloblastomas could arise from dentigerous cyst walls; thus, the development of ameloblastoma from dentigerous cysts may be due to differential protein expression. Our aim was to identify a membrane protein that is differentially expressed in ameloblastomas with respect to dentigerous cysts.

METHODS

We analyzed the SDS-PAGE profiles of membrane proteins from ameloblastomas and dentigerous cysts. The protein in a band present in the ameloblastoma sample, but apparently absent in the dentigerous cyst sample was identified via mass spectrometry as the chaperonin Hsp60. We used western blotting and immunohistochemistry to analyze its overexpression and localization in ameloblastoma.

RESULTS

We found a differential band of 95 kDa in the membrane proteins of ameloblastoma. In this band, the chaperonin Hsp60 was identified, and its overexpression was corroborated using western blotting and immunohistochemistry. Hsp60 was localized in the plasma membrane of all ameloblastoma samples studied; in addition, it was found in the cell nucleus of the plexiform subtype of conventional ameloblastoma.

CONCLUSIONS

Our results suggest that Hsp60 may be involved in ameloblastoma development, and could therefore be a potential therapeutic target for ameloblastoma treatment.

In silico evaluation of drugs used in treatment of oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a chronic T cell-mediated, immunological, mucocutaneous disease with a number of genes and inflammatory mediators implicated in its pathogenesis. Heart shock protein 70 and the proinflammatory mediator TNFα have been predominantly involved in the etiopathogenesis of oral lichen planus.

METHODS

In this study, the action of 27 commonly used drugs for treating OLP at HSP70 and TNFα were evaluated by molecular docking using Maestro Schrodinger version 10.1. X-ray crystallographic structures of the target proteins, that is, Heat Shock Protein 70 (PDB Code: 6FDT) and tumor necrosis factor alpha-1 (PDB Code: 1TNF) were obtained from Protein Data Bank (PDB). The structures of the ligands (27 drugs) were obtained from PubChem in.sdf format. Using Ligprep, pre-processing of the ligands was done. Extra-precision docking was performed with the prepared protein and the ligands.

RESULTS

With respect to HSP70, the highest dock score (-4.768) and glide score (-4.818) were seen with hydroxychloroquine (HCQ), followed by epigallocatechin gallate (green tea), methotrexate, and curcumin. The highest dock (-9.525) and glide score (-9.584) in TNFα were seen in with epigallocatechin gallate, followed by HCQ, dapsone, and methotrexate.

CONCLUSION

The results of the study tend to explain the clinical use of HCQ in recalcitrant and severe cases, as well as the anti-inflammatory property of epigallocatechin gallate. The results of the study open ventures for exploring the in silico behavior of drugs for effective pathological management.

Expression of keratins 8, 18, and 19 in epithelia of atrophic oral lichen planus

Keratins form intermediate filaments of the cytoskeleton in keratinocytes and have roles in cell structure, signaling, intracellular transport, and cell death. Oral lichen planus (OLP) is an oral inflammatory disease with derangements in basal keratinocytes and disruption of the basal membrane. Here, we focused on epithelial expression of keratins 8, 18, and 19 because these proteins are known to modulate cell death. Biopsies were taken from buccal oral mucosa of persons with normal oral mucosa (n = 10) or atrophic OLP (n = 10). Cultured normal oral keratinocytes (n = 4) showed expression of mRNA and protein for keratins 8, 18, and 19. Immunohistochemistry showed consistent staining for keratins 8 and 18 in basal keratinocytes of normal oral mucosa. In OLP, staining for keratin (K)8 was mostly negative and staining for K18 was weak. Keratin 19 was expressed irregularly in most biopsies of normal oral mucosa and not at all in OLP. Several mononuclear leukocytes in the cellular infiltrate showed membrane staining for K8 and K18. Positive staining for K16 confirmed partial collapse of the basal cell layer in OLP. The basal cell niche in OLP therefore appeared to be partly populated with keratinocytes demonstrating a higher degree of differentiation (K8^-  K18^-  K19^-  K16⁺ ); consequently, such areas may be more susceptible to the action of cell death factors released from the cell infiltrate as a result of lacking the protective, normal keratin present in the basal epithelial cell layer of normal oral mucosa.

Role and mechanism of the nod-like receptor family pyrin domain-containing 3 inflammasome in oral disease

OBJECTIVE

To summarize evidence and data from experimental studies regarding the role and mechanism of the Nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in the pathogenesis of several representative oral diseases.

MATERIALS AND METHODS

A literature search of PubMed and EBSCO was performed. The literature was searched using a combination of keywords, e.g., NLRP3 inflammasome, inflammation, microorganisms, oral inflammatory diseases, and oral immunological diseases.

RESULTS

The initiation and activation of the NLRP3 inflammasome are associated with the pathogenesis and progression of several representative oral diseases, including periodontitis, oral lichen planus, dental pulp disease, and oral cavity squamous cell carcinoma.

CONCLUSIONS

The NLRP3 inflammasome plays a crucial role in the progression of inflammatory and adaptive immune responses. The possible role of the NLRP3 inflammasome in several oral diseases, including not only periodontitis and pulpitis but also mucosal diseases and oral cavity squamous cell carcinoma, may involve the aberrant regulation of inflammatory and immune responses. Understanding the cellular and molecular biology of the NLRP3 inflammasome is necessary because the NLRP3 inflammasome may be a potential therapeutic target for the treatment and prevention of oral inflammatory and immunological diseases.

Immune receptors CD40 and CD86 in oral keratinocytes and implications for oral lichen planus

Lichen planus (LP) is a chronic T-cell-mediated mucocutaneous inflammatory disease that targets stratified epithelia, including those lining the oral cavity. The intraoral variant of LP (OLP) is associated with interferon (IFN)-γ production by infiltrating T lymphocytes; however, the role of epithelial cells in the etiopathogenesis OLP is not completely understood. There is however a growing body of evidence regarding the involvement of epithelial-derived cytokines, immune receptors, and costimulatory molecules in the pathobiological processes that promote and sustain OLP. In the present study, we used a reverse transcriptase-polymerase chain reaction assay to assess whether CD40-a receptor found mainly on antigen presenting cells-and the costimulatory molecule CD86 were expressed in oral keratinocytes (three strains of primary normal oral keratinocytes and the H357 cell line) in the presence or absence of IFN-γ. To further characterize the involvement of CD40 in OLP, expression and distribution of receptor and ligand (CD40/CD154) in tissues from OLP were evaluated by immunohistochemistry. The present results are the first to show that both CD40 and CD86 are constitutively expressed at low levels in oral keratinocytes and that their expression was enhanced by IFN-γ stimulation. The intensity of CD40 staining in OLP tissues was strong. Taken together, the results strongly suggest that CD40 and CD86 play a role in the pathophysiology of oral inflammatory diseases such as OLP.

A Study on Vitamin D and Cathelicidin Status in Patients with Rosacea: Serum Level and Tissue Expression

Background

Rosacea is a chronic inflammatory disease characterized by centrofacial erythema. Excess cathelicidin is suggested to be important to the pathophysiology of the disease. Recently, presence of a vitamin D response element was revealed in the cathelicidin gene promoter.

Objective

The aim of this study was to determine whether vitamin D and cathelicidin are associated with rosacea, both serologically and histopathologically.

Methods

Subjects with rosacea and without chronic skin disorders were enrolled in the patient and control groups, respectively. Serum 25-hydroxy-vitamin D and cathelicidin levels were measured. Tissue expression of cathelicidin and vitamin D receptor were measured with immunostaining-intensity-distribution index.

Results

The mean serum 25-hydroxyvitamin D level of patients with rosacea was 12.18±5.65 ng/ml, which is lower than that of the controls (17.41±6.75 ng/ml). Mean serum cathelicidin levels in patients with rosacea and the controls were 85.0±26.1 ng/ml and 55.0±23.3 ng/ml, respectively. Cathelicidin expression in rosacea tissue was significantly higher than that in control tissue (5.21 vs. 4.03). No significant difference was observed in vitamin D receptor expression.

Conclusion

Higher cathelicidin expression in rosacea supports the hypothesis that an abnormal inflammatory response of the innate immune system is important in pathogenesis of rosacea, but the role of high cathelicidin serum levels is complicated. Serum vitamin D was lower in patients with rosacea, although serum cathelicidin was higher than that of the controls. This suggests that the role of vitamin D level in the pathogenesis of rosacea merits further investigation.

New evidence of connections between increased O-GlcNAcylation and inflammasome in the oral mucosa of patients with oral lichen planus

Oral lichen planus (OLP) is considered a chronic inflammatory immune-mediated disease of the oral mucosa. Immunopathogenesis of OLP is thought to be associated with cell-mediated immune dysregulation. O-GlcNAcylation is a form of reversible glycosylation. It has been demonstrated that O-GlcNAcylation promoted nuclear factor kappa B (NF-κB) signalling. Activation of NF-кB can induce expression of nucleotide-binding domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, which is a large intracellular multi-protein complex involving an immune response. Dysregulated expression of the NLRP3 inflammasome was reported to be associated with autoinflammatory diseases. No integrative studies between O-GlcNAcylation and NLRP3 inflammasome in OLP patients have been reported. The present study aimed to determine the immunohistochemical expression of O-GlcNAcylation, NF-κB signalling molecules and NLRP3 inflammasome in oral mucosae of OLP patients. Oral tissue samples were collected from 30 OLP patients and 30 healthy individuals. Immunohistochemical staining and analyses of immunostaining scores were performed to evaluate expression of O-GlcNAcylation, NF-κB signalling molecules and NLRP3 inflammasome. According to observations in this study, significantly higher levels of O-GlcNAcylation, NF-κB signalling molecules and NLRP3 inflammasome were demonstrated in OLP patients compared with control subjects (P < 0·001). Positive correlations among O-GlcNAcylation, NF-κB signalling molecules and NLRP3 inflammasome were also observed in OLP samples (P < 0·01). In conclusion, the present study provides supportive evidence that increased O-GlcNAcylation is associated with increased expression of NLRP3 inflammasome via the NF-κB signalling pathway. These findings provide a new perspective on immunopathogenesis of OLP in relation to autoinflammation.

Increased melatonin in oral mucosal tissue of oral lichen planus (OLP) patients: A possible link between melatonin and its role in oral mucosal inflammation

OBJECTIVE

The existence of extra-pineal melatonin has been observed in various tissues. No prior studies of melatonin in human oral mucosal tissue under the condition of chronic inflammation have been reported. The aim of this study was to investigate the presence of melatonin in oral mucosal tissue of patients with oral lichen planus (OLP) which was considered as a chronic inflammatory immune-mediated disease causing oral mucosal damage and ulcerations.

MATERIALS AND METHODS

Sections from formalin-fixed and paraffin-embedded oral mucosal tissue of OLP patients (n=30), and control subjects (n=30) were used in this study. Immunohistochemical staining was performed and the semiquantitative scoring system was used to assess the levels of arylalkylamine-N-acetyltransferase (AANAT: a rate-limiting enzyme in the biosynthesis pathway of melatonin), melatonin, and melatonin receptor 1 (MT1) in oral mucosa of OLP patients and normal oral mucosa of control subjects.

RESULTS

AANAT, melatonin, and MT1were detected in oral mucosal tissue of OLP patients and control subjects. Immunostaining scores of AANAT, melatonin, and MT1 in oral mucosal tissue of OLP patients were significantly higher than those in control subjects (p=0.002, p<0.001, and p=0.031, respectively).

CONCLUSIONS

Increased levels of AANAT, melatonin, and MT1 in the inflamed oral mucosal tissue of OLP patients imply that chronic inflammation may induce the local biosynthesis of melatonin via AANAT, and may enhance the action of melatonin via MT1.

Immunohistochemical study of toll-like receptors 2, 4, and 9 expressions in pemphigus and bullous pemphigoid lesions

Pemphigus and bullous pemphigoid (BP) are severe autoimmune skin diseases. Whether innate immunity could be a trigger or a part of the pathogeneses is unknown. Toll-like receptors (TLRs) are important components of the innate immune system, with no previous evaluation of TLRs in autoimmune bullous diseases. This work aims to investigate TLRs 2, 4, and 9 expressions in pemphigus and bullous pemphigoid. Thirty-six patients with pemphigus vulgaris (PV), pemphigus foliaceus (PF), bullous pemphigoid (BP), and six healthy controls were studied. Skin biopsies from the patients and the controls were examined immunohistochemically for TLR2, 4, and 9 expressions. The TLR4 expressed mainly at the basal layer of epidermis in controls, but in the cases with autoimmune bullous diseases, TLR4 staining located at basal layer and suprabasal layer, even superficial layer of epidermis. The immunostaining-intensity-distribution (IID) index of TLR4 in patients with PF (13.83, P = 0.001), PV (13.08, P = 0.003), and BP (11.42, P = 0.042) were significantly higher than that of the controls (6.17). TLR2 and TLR9 showed no significantly changes at epidermal expression (P > 0.05) compared with controls. There was no correlation found between the expressions of these TLRs. This work, thus, shows a re-localization of TLR4 expression sites with increased expression in pemphigus and bullous pemphigoid lesions. Targeting TLR4 signaling is expected to be a novel treatment strategy for autoimmune bullous diseases.

The wonderous chaperones: A highlight on therapeutics of cancer and potentially malignant disorders

Diverse environmental and physiological factors are known to induce the transcription of a set of genes encoding special protective molecules known as "molecular chaperones" within our cells. Literature abounds in evidence regarding the varied roles; these "guides" can effectively perform in our system. Highly conserved through evolution, from the prokaryotes to the eukaryotes, these make perfect study tools for verifying their role in both the pathogenesis as well as the therapeutics of varied neurodegenerative, autoimmune and potentially malignant disorders and varied cancer states. We present a concise review of this ever dynamic molecule, highlighting the probable role in a potentially malignant disorder, oral lichen planus.

The expression and role of krüppel-like factor 4 in psoriasis

Background

Krüppel-like factor 4 (KLF4) is a transcription factor that regulates a diverse array of cellular processes, including development, differentiation, proliferation, and apoptosis. Although its function in keratinocytes has been widely studied, its exact role in psoriasis has not been elucidated.

Objective

We designed this study to investigate epidermal expression levels of KLF4 and the change in KLF4 expression after treatment in patients with psoriasis.

Methods

We compared the expression levels of KLF4 in the basal, suprabasal, and superficial epidermal layers, in psoriatic lesional, non-lesional, and normal skin, using an immunoreactivity intensity distribution index (IRIDI). In addition, we measured the change in KLF4 expression on the basis of the IRIDI and by reverse transcription polymerase chain reaction (RT-PCR) analysis after treatment.

Results

The combined IRIDI scores in psoriatic lesional skin were significantly higher than the scores in both non-lesional and normal skin. The psoriatic epidermis, particularly the suprabasal layer, showed a significantly increased IRIDI score compared to that of non-lesional and normal skin, which was significantly decreased after treatment. RT-PCR analysis exhibited a slight increase in KLF4 mRNA expression level after treatment; however, this increase was not significant.

Conclusion

These data indicate that KLF4 could regulate epidermal proliferation and differentiation. Moreover, we believe that KLF4 may play an important role in the physiological reaction to counteract abnormal differentiation and proliferation of keratinocytes.

Determination of cytokeratins 1, 13 and 14 in oral lichen planus

Introduccion: Cytokeratins (CK) are molecules of the cytoskeleton that contribute to the cellular differenciation. We studied the expression of CK1, CK13 and CK14 in thirty-three patients with OLP. The biopsied lesions were located in the dorsal surface of the tongue, the palatal keratinized mucosa and the nonkeratinized buccal mucosa. Objectives: This study aimed to determine the expression of CK1, CK13 and CK14 in oral lichen planus (OLP) and its relations with: clinical patterns, prognosis, drugs and tobacco intake and histopathological features. Study Design: Immunohistochemical analysis, retrospective, descriptive, observational and no randomized study. Results: No significant difference was observed in the expression of CK1 in patients with or without drug treatment. No association was found with the amount of drugs intake or smoking nor with the histopathological features examined. Samples immunostained with CK13 were all positive in the suprabasal layers, and 13 of them in the basal layer. In these last ones, statistical analysis showed significance in the grade of vacuolization of the basal layer (p=0.023) and in the degree of exocytosis (p=0.0025), this, making the degree of affection higher for both parameters. Thirty-two tissue sections were immunostained with CK14. CK14 was expressed in the basal layer in 97% of samples and in the suprabasal layer in 94% of samples. Conclusions: The three CK were altered in OLP. CK1 does not have a direct connection with the presence of orthokeratosis. The finding of the CK13 in the basal layer is related to the agression of the lymphocytic infiltration in the epithelium, due to the basal stratum vacuolization and the increase in lymphocytic exocitosis. The presence of CK14 in the suprabasal stratums is not a parameter to predict malignancy. The CK in OLP do not follow the normal pattern of keratinized or non-keratinized mucosa.

Key words:Basal cell vacuolization, CK1, CK13, CK14, cytokeratin, lymphocytic exocytosis, oral lichen planus.

Oral lichen planus: focus on etiopathogenesis

Lichen planus is a chronic mucocutaneous inflammatory disease, which frequently affects the oral mucosa of white females over 40 years old. Its aetiology remains uncertain and the pathogenesis is still the object of much speculation. The present paper presents the most well known antigens, and describes the action of different cells and proteins associated with the development of that disease, as well as the possible agents involved with its malignant transformation. Different external agents, especially virus, and internal agents, like stress, and the heat shock protein antigen expression, associated or not, can alter the basal keratinocytes of the oral mucosa making them susceptible to apoptosis by CD8(+) cytotoxic T cell as well as activate matrix metalloproteinase and mast cell degranulation, which produce a great range of inflammatory mediators and cytokines determining the clinical onset of the disease. Regarding carcinogenesis, since it is a complex process and presents multifactorial origin, it is believed that there may be a synergism between intrinsic, such as inflammation mediators, and extrinsic agents (tobacco, alcohol, viral infections) for the OLP malignant transformation to occur. However, further studies are needed to better understand the origin, pathogenesis and process of malignant transformation of OLP.

Proteomics-based identification of HSP60 as a tumor-associated antigen in colorectal cancer

Patients with cancer frequently develop autoantibodies. The identification of tumor autoantigens may have utility in early cancer diagnosis and immunotherapy. In this study, we used serological proteomics analysis (SERPA) to identify tumor proteins that elicit humoral response in colorectal cancer (CRC). The CRC cell line HCT116 was used as a source of proteins for 2-DE and subsequent Western blot analysis in which individual serum from patients with CRC was analyzed for autoantibodies. An autoantibody against HSP60 identified by MS was detected in 13 out of 25 patients with CRC and 1 out of 15 healthy subjects. In addition, the HSP60 expressions in tumor tissues collected from 40 patients with CRC were assessed by immunohistochemistry, and serum specimens from 100 patients with cancer and 30 healthy controls were screened for antibody titer to HSP60 by ELISA. The results showed that expressions of HSP60 in tumor tissue and serum antibody titer to HSP60 were significantly higher in patients with CRC than in healthy subjects. Thus, we conclude that the SERPA is an excellent assay for the identification of tumor-associated antigens and tumor markers. The detection of HSP60 may have clinical utility in CRC screening, diagnosis, and immunotherapy.

Altered expression of HSP70 in oral lichen planus

Background:

Oral lichen planus (OLP), a well-known mucocutaneous lesion has been the center of debate regarding its obscure etiopathogenesis. Recent highlight has been placed on the role of autoimmunity and a sect of constitutional molecules, the native chaperones HSP70, proposed to be important in the onset and progress of disease.

Aim:

To substantiate a potential role of HSP70 in the pathogenesis of oral lichen planus.

Settings and Design:

The study involved immunohistochemical (IHC) analyses in a laboratory under monitored conditions. It was a retrospective study on clinically and histopathologically confirmed specimens.

Materials and Methods:

30 samples of confirmed cases of OLP were selected and grouped on the basis of the thickness of the epithelial layer into atrophic, normal (classical) and acanthotic. An immunohistochemical analysis of the expression of HSP70 protein was done, followed by a quantitative and qualitative analysis of the stained layers.

Statistical Analyses:

A Z test was performed to estimate the difference observed between two sample proportions. The statistics was given at 1% level of significance i.e. P<0.01.

Results:

An increased expression of HSP70 was noted in the basal and suprabasal cells of the epithelium of OLP. A higher count and intensity of HSP70 expression was seen in the basal layer of the epithelium. Greater expression was noted in the epithelium of the atrophic group.

Conclusion:

The expression pattern of HSP70 positively implicates it in the pathogenesis of OLP.

Expression of cytokeratins 10, 13, 14 and 19 in oral lichen planus

OLP is a chronic inflammatory disease of unknown etiology that may develop into squamous-cell carcinoma. Cytokeratins, which are important components of the cytoskeleton, are excellent epithelial differentiation markers used to study neoplastic and inflammatory diseases. To study the profile of cytokeratins in OLP and their possible association with dysplastic alterations, monoclonal antibodies were used for cytokeratins 10, 13, 14 and 19, in 26 samples of OLP. The streptavidin-biotin technique was employed in paraffin-embedded tissue sections. Sample analysis revealed suprabasal expression of cytokeratin 10 in 16/17 samples, 14 of them with reduced expression; suprabasal expression of cytokeratin 13 in 18/23, 16 of them with delay; basal and suprabasal expression of cytokeratin 14 in all samples; and focal basal expression of cytokeratin 19 in 4/21. Expression of cytokeratins 10, 13 and 14 was altered in OLP lesions. The inflammatory process and hyperkeratosis or parakeratosis seem to have interfered with the expression of these CKs. Cytokeratin 19 was expressed in the lesions, in a pattern similar to that mentioned in the literature for the non-keratinized oral mucosa. The presence of mild dysplasia did not change the expression of the cytokeratins studied. No differences in pattern of expression were observed between keratinized and non-keratinized areas in the lesions caused by OLP.

The alteration of Id-1 and TSP-1 expression in mucoepidermoid carcinoma associated with its clinical features and prognosis

Expression of Id-1 (inhibitors of DNA binding/differentiation protein 1) and TSP-1 (thrombospondin-1) in mucoepidermoid carcinoma and their relationship to pathological features and prognosis was studied. Moderately and poorly differentiated groups had significantly higher Id-1 positive expression rate (p<0.05) than well differentiated carcinoma. Stages III-IV showed significant increase of Id-1 positive expression rate (p<0.05) compared with stages I and II. Id-1 positive expression was significantly higher in patients with cervical lymph node metastasis or relapse at 5 years (p<0.05). After that, patients with negative Id-1 expression had significantly higher tumor-free survival than patients with positive expression (p<0.05). Correlation between the expression of Id-1 and TSP-1 in mucoepidermoid carcinoma was negative (p<0.05). Poorly differentiated groups show significantly lower TSP-1 positive expression rate than well differentiated groups (p<0.05). No significant differences of TSP-1 positive expression were detected with clinical stage. TSP-1 positive expression was significantly lower in patients with cervical lymph node metastasis or relapse at 5 years (p<0.05). After 5 years, patients with positive TSP-1 expression had significantly higher tumor-free survival than patients with negative TSP-1. Positive Id-1 expression is associated with high malignancy/poor prognosis; positive TSP-1 expression is associated with low malignancy/good prognosis. Protein expression status may help assess tumor malignancy and patient prognosis.

Soluble forms of Toll-like receptor 4 are present in human saliva and modulate tumour necrosis factor-alpha secretion by macrophage-like cells

In health, mucosal inflammation is prevented by tightly regulated responses via Toll-like receptors (TLR) that interact with specific microbe associated molecular patterns. Currently, 13 TLRs have been identified. Based on the specificity of ligand recognition, TLR-2 and TLR-4 can recognize most oral commensal microorganisms. Recent identification of some soluble TLRs (sTLRs) suggests additional regulatory roles for these receptors. We report here the presence of sTLR-4 polypeptides in adult human saliva. Functionally, the salivary sTLR-4 suppressed cytokine secretion by activated macrophages. The sTLR-4 levels were elevated significantly in oral lichen planus (OLP), a chronic inflammatory condition of the oral mucosa characterized by clinical persistence. In contrast, the epithelial cells in the saliva of OLP subjects expressed significantly reduced TLR-2 and TLR-4 mRNA that correlated with fewer bacteria/salivary epithelial cells. Investigating the soluble and cellular components of saliva is useful in identifying potential biomarkers for oral mucosal lesions.

Lichenoid tissue reaction/interface dermatitis: clinical and histological perspectives

A number of uncommon, clinically diverse and poorly understood inflammatory skin diseases are linked by the presence of a set of histopathological elements that have traditionally been referred to as the "lichenoid tissue reaction/interface dermatitis" (LTR/IFD). The prototypic skin disease in this category is lichen planus. However, the LTR/IFD can also be seen in skin disorders associated with systemic illnesses (lupus erythematosus, dermatomyositis), and the skin changes of potentially fatal disorders such as graft-versus-host disease, Stevens-Johnson syndrome, and toxic epidermal necrolysis. It has been traditionally felt that cytotoxic T-lymphocytes represent the final effector cell type for the epidermal basal cell layer injury pattern that is common to LTR/IFD disorders. Recent work has suggested that a number of different LTR/IFD skin disorders share a common inflammatory signaling pathway involving the actions of plasmacytoid dendritic cell-derived IFN-alpha. This signaling pathway appears to amplify cytotoxic T cell injury to the epidermal basal cell compartment. This review will summarize the work implicating this pathway as well as the other cellular and molecular mechanisms that are thought to be responsible for the prototypic LTR/IFD disorder, lichen planus. It is hoped that a better understanding of the immunological commonalities shared by various LTR/IFD disorders will lead to more effective safer treatment options for these illnesses.

Comparison of expression of heat-shock protein 60, Toll-like receptors 2 and 4, and T-cell receptor gammadelta in plaque and guttate psoriasis

BACKGROUND

Psoriasis is a chronic skin disease that appears to be autoimmune in nature. Recently, it is thought that microbial pathogens of skin can affect the pathogenesis of psoriasis by inducing autoimmunity. Heat-shock proteins (HSPs) are known to play an important role in immune and inflammatory responses of the skin including psoriasis. Recent studies have suggested that Toll-like receptors (TLR) 2, 4 and gammadelta T-cell receptors (TCR-gammadelta) may recognize HSP60 as a ligand and consequently activate the immune system.

METHODS

The biopsy specimens of 12 of guttate psoriasis, 12 of plaque psoriasis and five of normal skin were studied using immunohistochemical staining. The expressions of HSP60, TLR2 and TLR4 were evaluated using an immunostaining-intensity-distribution (IID) index and TCR-gammadelta positive cells were counted.

RESULTS

The expression of HSP60 was significantly higher in guttate and plaque psoriasis than in normal skin. The expression of TLR4 was higher in guttate psoriasis than in plaque psoriasis and normal skin. The expression of TCR-gammadelta was higher in guttate and plaque psoriasis than in normal skin, but there was no correlation found between the expression of HSP60 and TLRs 2 and 4, or between that of HSP60 and TCR-gammadelta.

CONCLUSIONS

HSP60 may be related to the pathogenesis of both guttate and plaque psoriasis and TLR4 may be related to the pathogenesis of guttate psoriasis.

Heat shock proteins (HSP70 and HSP27) as markers of epithelial dysplasia in oral leukoplakia

Heat shock proteins (HSPs) play a significant role in cell proliferation, differentiation, and oncogenesis. HSP70 and HSP27 are constitutively and gradually expressed in a broad range of normal tissues and neoplasms, and their expression has been assessed as markers for oral epithelial dysplasia. The study involved 43 patients with oral leukoplakia (OL): 23 were categorized as nondysplastic and 20 as dysplastic OLs. Immunohistochemistry was carried out with the monoclonal antibodies HSP70 and HSP27. The presence of epithelial dysplasia and its histologic grading was evaluated according to the World Health Organization classification: mild, moderate, and severe squamous epithelial dysplasia. Expression of HSPs within the epithelium was also evaluated. The difference in the percentage of HSP70 positive nuclei in nondysplastic and dysplastic OL reached statistical significance(Equation is included in full-text article.)95% confidence interval = 17.74-43.82; P = 0.000). None of the 43 specimens analyzed showed positive nuclear immunostaining for anti-HSP27 antibody. No significant difference for HSP27 cytoplasmic expression could be identified between OL with or without epithelial dysplasia(Equation is included in full-text article.)95% confidence interval = 0.44-3.95; P = 0.89). It is concluded that the nuclear HSP70 immunoexpression could be an objective marker for the presence of the epithelial dysplasia in OL.

Immunohistochemical analysis of P57(kip2), p53 and hsp60 expressions in premalignant and malignant oral tissues

To investigate the expressions and significances of P57(kip2), p53 and hsp60 proteins in the dysplasia-carcinoma sequence of oral mucosa. A retrospective study was performed in 10 cases of normal oral mucosa, 79 cases of leukoplakia and 67 cases of squamous cell carcinoma (SCC). The expressions of P57(kip2), p53 and hsp60 proteins were detected in the tissue samples of these populations using immunohistochemical method. P57(kip2) expression was decreased in oral leukoplakia with moderate or severe dysplasia, and further decreased in oral SCC. Negative expression of P57(kip2) was significantly associated with advanced tumor size, the occurrence of lymph node metastasis and the advanced clinical stage in oral SCC. The overall 5-year survival rate in the P57(kip2) positive group was significantly higher than that in the P57(kip2) negative group. P57(kip2) expression was decreased in oral leukoplakia with moderate or severe dysplasia, and further decreased in oral SCC. It was a remarkable progressive and prognostic biomarker in oral SCC.

Current controversies in oral lichen planus: Report of an international consensus meeting. Part 1. Viral infections and etiopathogenesis

Despite recent advances in understanding the immunopathogenesis of oral lichen planus (LP), the initial triggers of lesion formation and the essential pathogenic pathways are unknown. It is therefore not surprising that the clinical management of oral LP poses considerable difficulties to the dermatologist and the oral physician. A consensus meeting was held in France in March 2003 to discuss the most controversial aspects of oral LP. Part 1 of the meeting report focuses on (1) the relationship between oral LP and viral infection with special emphasis on hepatitis C virus (HCV), and (2) oral LP pathogenesis, in particular the immune mechanisms resulting in lymphocyte infiltration and keratinocyte apoptosis. Part 2 focuses on patient management and therapeutic approaches and includes discussion on malignant transformation of oral LP.

Heat shock proteins 60 and 70 expression of cutaneous lichen planus: comparison with normal skin and psoriasis vulgaris*

BACKGROUND

Heat shock proteins (HSPs) are expressed by most living cells and play fundamental roles in many biological processes. Their synthesis increases by a variety of stresses in order to enable cellular survival. Although it is known that they play an important role in immune and inflammatory responses of the skin, the role of HSPs in the pathogenesis of skin diseases has been studied in only limited skin diseases. Lichen planus (LP) is a relatively common papulosquamous dermatosis, and cell-mediated immunity plays an important role in its pathogenesis. Although an altered expression of certain HSPs was reported in oral LP lesions, the expression of HSPs in cutaneous lesions of LP has not been investigated. In this immunohistochemical study, we aimed at investigating the role of HSPs in the pathogenesis of LP by studying whether there is any difference in HSP expression in cutaneous lesions of LP when compared to normal skin and psoriasis vulgaris (PV).

METHODS

Formalin-fixed paraffin-embedded skin biopsy specimen blocks from LP patients (n = 39), patients with psoriasis (n = 20), and normal skin controls (n = 20) were used in the study. Antibodies to HSPs 60 and 70 were applied immunohistochemically by using streptavidin-biotin-horseradish peroxidase complex. An immunoreactivity intensity distribution index (IRIDI) was calculated to express the proportion of the immunoreactive cells as well as the staining intensity in different layers of the epidermis.

RESULTS

The mean IRIDI scores for HSP60 expression in the basal, suprabasal, and superficial epidermal layers of cutaneous LP were moderately higher than those of normal skin, but not different from those of PV skin. These scores for HSP70 in lesions of LP were moderately lower than those for normal skin in the basal layer, but not significantly different from normal in the other two layers. Scores for HSP70 in PV lesions were markedly lower in all three layers. In the cells of the inflammatory infiltrates (mostly lymphocytes), HSP60 scores for LP were moderately higher, compared to those for PV, whereas scores for HSP70 were much lower for LP and very much lower for PV.

CONCLUSIONS

Significantly altered levels of HSP proteins were found in cutaneous LP lesions in comparison with normal skin and psoriasis, suggesting the role of HSPs in the pathogenesis of LP.

Expression of heat shock protein (HSP70) in oral lichen planus and non-dysplastic oral leucoplakia

The purpose of this study was to investigate the expression of heat shock protein (HSP70) in oral non-dysplastic leucoplakia and in relation to the clinical and pathological features of oral lichen planus. The expression of HSP70 was assessed in the epithelial compartment of normal mucosa (n = 5), oral lichen planus (n = 28) and benign leucoplakia (n = 11) using an immunohistochemical method. The immunostaining intensity distribution (IID) index was used to quantify the positivity of the staining. There was no association between HSP70 overexpression and clinical presentation of oral lichen planus. Oral lichen planus patients showed no statistically significant differences in the depth of the inflammatory infiltrate when expression of HSP70 was considered (X(i)- X(j) = 42.30; 95% confidence interval (95% CI) = -120.87-205.48). No statistically significant differences were identified in terms of HSP70 expression between oral lichen planus and normal buccal mucosal specimens (X(i)- X(j) = 4.07; 95% CI = -0.53-8.67). The IID index score for HSP70 expression in leucoplakia specimens was significantly higher than the one of the oral lichen planus group (X(i) - X(j)= 5.11; 95% CI = 1.73-8.48). It is concluded that there are no statistically significant differences in HSP70 expression between oral lichen planus and normal buccal mucosal specimens, suggesting that HSP70 does not play an obvious part in the pathogenesis of oral lichen planus. The expression of HSP70 was significantly higher in oral leucoplakia than in oral lichen planus, possibly because of differences in cellular activity or cell proliferation.

Oral lichen planus part I: epidemiology, clinics, etiology, immunopathogeny, and diagnosis

This article presents a review of the literature on oral lichen planus, focusing on important aspects of its epidemiology, etiopathogeny, and clinical manifestations. The oral form is an important clinical presentation of lichen planus. It may precede or accompany the skin lesions, or it may be the only manifestation of the disease. Dermatologists, dentists, otorhinolaryngologists, and other specialists who deal with the oral cavity must be aware of this disease so they can diagnose, treat, and keep these patients under observation.

Position Paper: Oral Features of Mucocutaneous Disorders

Part of periodontology involves the diagnosis and treatment of a variety of non-plaque-related diseases of the periodontium. The International Workshop for a Classification of Periodontal Diseases and Conditions noted that the periodontist may be called upon to manage non-plaque-related mucocutaneous disorders either alone, or as part of a treatment team consisting of physicians, dentists or other allied health care professionals. This informational paper will review the etiology, clinical manifestations, diagnosis, and treatment of the most common chronic mucocutaneous diseases, including those that may present as desquamative gingivitis or intraoral vesiculobullous lesions. This paper is intended for the use of periodontists and other members of the dental profession.

Accumulation of oligoclonal T cells in the infiltrating lymphocytes in oral lichen planus

BACKGROUND

Identification of a disease-specific and possibly pathogenic T-cell receptor (TCR) in oral lichen planus (OLP) is one of the most important steps to reveal the pathogenic antigen recognized by the T cells and thereby elucidate the pathogenesis and etiology of OLP.

METHODS

In buccal mucosa biopsy specimens and peripheral blood mononuclear cells (PBMC) from seven patients with OLP, the TCR V beta gene usage was examined by polymerase chain reaction-based and single-strand conformation polymorphism analyses.

RESULTS

The V beta families expressed in the biopsy specimens were markedly heterogeneous, but they were restricted in comparison to those observed in the PBMC. The V beta families predominantly expressed in the biopsy specimens in comparison with the PBMC were still heterogeneous in individual patients and differed from patient to patient; however, V beta 2, V beta 6, and V beta 19 were commonly predominant in the biopsy specimens from more than half of the patients. Among the V beta families predominantly expressed in the biopsy specimens, the accumulation of T-cell clonotypes was observed in the majority of the V beta families including V beta 6 and V beta 19; however, it was not observed in the minority of the V beta families including V beta 2.

CONCLUSIONS

These results suggest that unique T-cell populations bearing V beta 2, V beta 6, or V beta 19 gene products tend to expand in OLP lesions as a consequence of in situ stimulation with a restricted epitope of either a nominal antigen on the MHC molecule for the majority of the V beta families, even if only in minor populations, or of a common superantigen for the minority of the V beta families.

Expression of inducible nitric oxide synthase and heat shock proteins in periapical inflammatory lesions

BACKGROUND

The mechanisms responsible for activation and proliferation of lining epithelium involved in inflammatory processes in periapical inflammatory lesions remain unclear. In this study, the expression and distribution of inducible nitric oxide synthase (iNOS) and heat shock proteins (HSPs) were immunohistochemically investigated in periapical inflammatory lesions.

METHODS

Control specimens of periodontal ligaments including Malassez epithelial rests from seven teeth and periapical inflammatory lesions (15 apical granulomas (AGs), 16 radicular cysts (RCs), and 10 residual radicular cysts (RRCs)) were prepared and examined by the standard streptavidin-biotin peroxidase complex method using anti-iNOS rabbit polyclonal antiserum, and anti-HSP27, -HSP60, -HSP70 mouse monoclonal antibodies.

RESULTS

Immunoreactivity for iNOS was detected in macrophages, lymphocytes, and endothelial cells of granulation tissue and in lining epithelium of periapical inflammatory lesions. Malassez epithelial rests showed no or slight staining for iNOS. The epithelial staining intensity of iNOS in RCs was greater than that in Malassez epithelial rests and RRCs. Immunoreactivity for HSP27 was recognized in inflammatory cells, endothelial cells and lining epithelium of periapical inflammatory lesions and in Malassez epithelial rests. HSP60 was detected in some lymphocytes of granulation tissue and in lining epithelium of periapical inflammatory lesions, whereas Malassez epithelial rests showed no staining for HSP60. Epithelial HSP60 reactivity was more intense in RCs than in RRCs. HSP70 was expressed in lymphocytes, endothelial cells and lining epithelium of periapical inflammatory lesions and in Malassez epithelial rests. The staining intensity of HSP70 in Malassez epithelial rests was slightly lower than that in lining epithelium of RCs and RRCs.

CONCLUSIONS

These data demonstrate that the expressions of iNOS, HSP60, and HSP70 are involved in inflammatory processes and might play a role in the activation and proliferation of lining epithelium, leading to progression of periapical inflammatory lesions.

Hypersensitivity of the oral mucosa: clinics and pathology

Hypersensitivity reactions of the oral mucosa comprise an array of clinical manifestations. Some of the reactions are difficult to differentiate from toxic reactions. Hypersensitivity reactions of type I, type III, and type IV are well known, although, especially for types I and III, they are rarely encountered. Type-I reactions are most frequently seen related to application of polymers in the oral cavity, such as orthodontic bonding and fissure sealant materials. There may also be systemic manifestations such as urticaria. Type-IV reactions may be seen related to most dental materials used, from amalgam and gold to polymers. These reactions appear as chronic reddening and/or ulceration of the oral mucosa. Lichenoid reactions have histopathological characteristics compatible with type-IV hypersensitivity reactions and are the most prevalent material-adverse reactions seen in the oral cavity. A special variety inside the lips with multiple papules and/or diffuse redness has recently been identified. This lesion comprises a serious treatment challenge. Skin patch tests, applying a series of dental materials in non-toxic concentrations on the skin, have been used to identify sensitization. However, the value of those tests can be questioned. Exacerbation of geographic stomatitis may be another form of hypersensitivity to dental materials.

Immunohistochemical study of oral lichen planus associated with hepatitis C virus infection, oral lichenoid contact sensitivity reaction and idiopathic oral lichen planus

OBJECTIVES

Oral lichen planus (OLP) is a common mucocutaneous disorder and might be associated to a possible pathogenic relationship with hepatitis C virus (HCV) infection or hypersensitivity to dental alloy. We examined the clinical and immunohistochemical features of OLP associated with HCV infection (OLP-HCV), oral lichenoid contact sensitivity reaction (OLCSR), and idiopathic oral lichen planus (iOLP). The immunohistochemical expressions of CD4, CD8, B cells, Class II major histocompatibility complex antigen (HLA-DR), S-100, HSP60, Proliferating cell nuclear antigen (PCNA) and Ki-67 were compared to study the pathogenic differences of the three OLP groups.

MATERIALS AND METHODS

Three groups of OLP patients, (I) OLP-HCV patients (n = 17), (2) OLCSR patients (n = 10) and (3) iOLP patients (n = 14) were retrieved from clinical records and tissues examined immunohistochemically by the avidin-biotin-complex technique.

RESULTS

The patients with OLP-HCV showed widespread lesions. The proportion of CD8+ cells was found to be significantly higher in the lamina propria of the OLP-HCV patients and a significantly lower proportion of CD8+ cells of the OLCSR patients was noticed in the epithelium or the connective tissue papillae than in the iOLP patients. There were no significant differences in either the number of CD4+ cells or B cells between the three OLP groups. No significant differences in the number of HLA-DR+ cells were found between the three OLP groups and some OLP-HCV patients showed a significant increase of S-100+ cells in the epithelium compared with iOLP patients. There were no significant differences in either the number of PCNA+ or Ki-67+ cells between the groups. The patients showed similar weak expressions of HSP60 in the three OLP groups.

CONCLUSION

The different distributions of the CD8+ cells that could have functionally different roles might be related to the distinct pathogenic mechanisms in the three OLP groups.