Inflammation-related cytokines in oral lichen planus: an overview

The Tipped Balance of ILC1/ILC2 in Peripheral Blood of Oral Lichen Planus Is Related to Inflammatory Cytokines

Oral lichen planus (OLP) is an immune-inflammatory disease mediated by T cells. Innate lymphoid cells (ILCs) constitute a novel family of immune cells that initially originate from common innate lymphoid progenitors. Termed “T cells counterparts,” ILCs play a prominent role in inflammatory-immune diseases. However, the characterization of ILCs and their related induced factors were unclear in OLP. In the present study, the phenotypic characteristics of ILCs and their correlation with inflammatory cytokines were explored in the peripheral blood of OLP patients and healthy controls. We found that the proportion of total ILCs was expanded in OLP and was positively correlated with disease severity. The highly skewed distribution of ILC subpopulations was notable in OLP. Specifically, the frequency of ILC1s was significantly increased, while that of ILC2s was significantly reduced in total ILCs of OLP, resulting in the markedly elevated ILC1/ILC2 ratio in OLP. Correspondingly, ILCs in OLP displayed high expression of T-bet but low expression of GATA3. In addition, the IFN-γ expression level was elevated in ILC1s, whereas the IL-4 expression level was decreased in ILC2s. Moreover, ILC-associated activators IL-12, IL-18, and IL-1β were upregulated in OLP plasma, with IL-12 and IL-1β both positively correlated with the ILC1/ILC2 ratio. Further in vitro stimulation tests indicated that OLP plasma remarkedly increased the ILC1/ILC2 ratio, especially that IL-12 and IL-1β tipped the balance between ILC1s and ILC2s toward ILC1s in total ILCs. Overall, elevated levels of IL-12 and IL-1β might act as environmental cues in tipping the balance of ILC1/ILC2 in the peripheral blood of OLP, contributing to the immune dysregulation in OLP.

Immune mechanisms in oral lichen planus

Oral lichen planus (OLP) is a T-cell-mediated inflammatory disease of the oral mucosa that has been extensively researched over many years but as yet the mechanisms of pathogenesis are still not fully understood. Whilst the specific etiologic factors driving OLP remain ambiguous, evidence points to the development of a chronic, dysregulated immune response to OLP-mediating antigens presented by innate immune cells and oral keratinocytes leading to increased cytokine, chemokine and adhesion molecule expression. These molecules recruit T-cells and mast cells to the diseased site and orchestrate a complex interplay between cells that culminates in keratinocyte cell death, mucosal basement membrane destruction and long-term chronicity of the disease. The main lymphocytes involved are thought to be CD8+ cytotoxic and CD4+ Th1 polarised T-cells although recent evidence indicates the involvement of other Th subsets such as Th9, Th17 and Tregs, suggesting that a more complex immune cell relationship exists during the disease process. This review provides an overview of the immune mechanisms at play in OLP pathogenesis with particular emphasis on the role of the different Th subsets and how these recent discoveries may guide research toward identifying potential therapeutic targets.

Reveals of quercetin's therapeutic effects on oral lichen planus based on network pharmacology approach and experimental validation

Oral lichen planus (OLP) is a localized autoimmune disease of the oral mucosa, with an incidence of up to 2%. Although corticosteroids are the first-line treatment, they cause several adverse effects. Quercetin, a naturally occurring compound, has fewer side-effects and provides long-term benefits. Besides, it has powerful anti‑inflammatory activities. Here, we combined network pharmacology with experimental verification to predict and verify the key targets of quercetin against OLP. First, 66 quercetin-OLP common targets were analyzed from various databases. The protein–protein interaction (PPI) network was constructed. Topology analysis and MCODE cluster analysis of common targets were conducted to identify 12 key targets including TP53, IL-6 and IFN-γ and their connections. Gene functions and key signaling pathways, including reactive oxygen species metabolism, IL-17 pathway and AGE-RAGE pathway, were enriched by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Then, in vitro experiments showed that quercetin interfered with Th1/Th2 balance by acting on IL-6 and IFN-γ to modulate the immune system in treating OLP. Quercetin considerably affected the apoptosis and migration of T lymphocytes in OLP patients. Our study reveals the potential therapeutic targets and signaling pathways of quercetin associated with OLP, and establishes the groundwork for future clinical applications.

Intralesional and peripheral plasma of oral lichenoid reactions exhibit different cytokine profiles: A preliminary study

Background/purpose

Oral lichenoid reactions (OLRs) are commonly characterized by the infiltration and activation of inflammatory cells at the interface of the oral mucosa. This study aimed to compare the cytokine profiles between intralesional and peripheral plasma from patients with OLRs and elucidate the cytokine profile in the OLR microenvironment.

Materials and methods

A total of 26 paired intralesional and peripheral plasma samples were collected from patients with OLRs. A panel of 15 cytokines was measured using a Luminex assay. The reticular, erythema, and ulcerative score was used to evaluate the degree of OLR severity.

Results

IL-10 was detected in a fewer number of intralesional samples (19/26) compared to peripheral samples (26/26, p = 0.01). The intralesional plasma exhibited significantly elevated levels of granzyme B (median 108.94 vs. 16.00), TGF-β1 (mean 30448.92 vs. 10199.04), TGF-β2 (mean 1659.73 vs. 1308.49), and TGF-β3 (mean 914.33 vs. 573.13) compared to the peripheral plasma (p = 0.001, p < 0.001, p < 0.001, and p < 0.001, respectively). The levels of intralesional IL-2 (median 2.84 vs. 3.45, p = 0.019) and TNF-α (median 7.66 vs. 10.34, p = 0.048) were significantly lower in the intralesional plasma compared to the peripheral plasma.

Conclusion

The intralesional concentrations of granzyme B and TGF-β were elevated, whereas IL-2 and TNF-α were decreased in the OLR microenvironment compared to the peripheral plasma. These findings may contribute to establishing a panel of biomarkers that can be used to monitor the disease activity of OLRs in a large cohort study in future.

Amorphous silica nanoparticles (nSP50) exacerbate hepatic damage through the activation of acquired cell-mediated immunity

Due to their innovative functions, the use of nanoparticles in various industries has been expanding. However, a key concern is whether nanoparticles induce unexpected biological effects. Although many studies have focused on innate immunity, information on whether nanoparticles induce biological responses through effects on acquired immunity is sparse. Here, to assess the effects of amorphous silica nanoparticles on acquired immunity, we analyzed changes in acute toxicities after pretreatment with amorphous silica nanoparticles (50 nm in diameter; nSP50). Pretreatment with nSP50 biochemically and pathologically exacerbated nSP50-induced hepatic damage in immunocompetent mice. However, pretreatment with nSP50 did not exacerbate hepatic damage in immunodeficient mice. Consistent with this, the depletion of CD8+ cells with an anti-CD8 antibody in animals pretreated with nSP50 resulted in lower plasma levels of hepatic injury markers such as ALT and AST after an intravenous administration than treatment with an isotype-matched control antibody. Finally, stimulation of splenocytes promoted the release of IFN-γ in nSP50-pretreated mice regardless of the stimulator used. Moreover, the blockade of IFN-γ decreased plasma levels of ALT and AST levels in nSP50-pretreated mice. Collectively, these data show that nSP50-induced acquired immunity leads to exacerbation of hepatic damage through the activation of cytotoxic T lymphocytes.

Lichen Planus

Lichen planus (LP) is a T cell-mediated disease affecting the stratified squamous epithelia of the skin and/or mucus membrane. Histologically, the disease is characterized by a lichenoid inflammatory infiltrate and vacuolar degeneration of the basal layer of the epidermis. LP has three major subtypes: Cutaneous, mucosal and appendageal LP. Rarely, it may affect the nails in the absence of skin and/or mucosal changes. LP may also be induced by several drugs, typically anti-hypertensive medication or be associated with infections, particularly viral hepatitis. The diagnosis is based on the clinical presentation and characteristic histological findings. Although the disease is often self-limiting, the intractable pruritus and painful mucosal erosions result in significant morbidity. The current first-line treatment are topical and/or systemic corticosteroids. In addition, immunosuppressants may be used as corticosteroid-sparing agents. These, however are often not sufficient to control disease. Janus kinase inhibitors and biologics (anti-IL-12/23, anti-IL17) have emerged as novel future treatment options. Thus, one may expect a dramatic change of the treatment landscape of LP in the near future.

Characterization and function of circulating mucosal-associated invariant T cells and γδT cells in oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory disease with uncertain aetiology. Mucosal-associated invariant T (MAIT) cells and γδT cells are unconventional, innate-like T cells with immunoregulatory capacity. This study aimed to investigate the potential effects of MAIT and γδT cells on the pathogenesis of OLP.

METHODS

Circulating MAIT cells and γδT cells were identified using flow cytometry. Surface proteins including CD4, CD8, CD69, CD103, CD49d, programmed death-1 (PD-1) and its ligand PD-L1 were assessed. Cytokines containing interleukin (IL)-4, IL-17, interferon (IFN)-γ, granzyme B and tumour necrosis factor (TNF)-α released by MAIT and γδT cells were measured following PMA and ionomycin stimulation.

RESULTS

Circulating MAIT and γδT cells were deficient in OLP. The percentage of CD4⁺ , CD69⁺ , CD103⁺ and PD-1⁺ MAIT cells was increased in OLP, while that of CD8⁺ and CD49d⁺ MAIT cells was decreased. The percentage of CD103⁺ , PD-1⁺ and PD-L1⁺ γδT cells was upregulated in OLP. Both the MAIT and γδT cells in OLP produced less IL-4 than controls. The granzyme B-producing MAIT cells were increased, while γδT cells secreting granzyme B and TNF-α were reduced in OLP. IL-17 and IFN-γ in OLP MAIT and γδT cells were not significantly different from that in controls. The frequency of OLP MAIT cells and the MAIT/γδT rate were positively associated with the disease severity.

CONCLUSION

The deficient MAIT and γδT cells expressing functional proteins and releasing cytokines may play an immunoregulatory role in the pathogenesis of OLP.

Effects of cold physical plasma on oral lichen planus: An in vitro study (Effects of CAP on OLP)

OBJECTIVES

In the search for more effective and safe treatment avenues, we investigated cold physical plasma as a new treatment modality for therapy of oral lichen planus (OLP).

MATERIAL AND METHODS

Healthy and diseased human mucosal tissue samples with a size of 3 mm in diameter obtained from OLP patients were subjected to plasma treatment ex vivo or were left untreated. Tissue sections were quantified for immune-infiltration of CD4+ , CD8+ , CD45RA+ , and CD45R0+ T cells. Moreover, the tissues' inflammatory profile was assessed by analyzing 12 different cytokines in the surrounding media.

RESULTS

A significantly increased infiltrate of CD8+ and CD45-R0+ T cells was detected in OLP tissue samples when compared to healthy tissue. A higher concentration of interleukin (IL) 1β, IL6, IL8, and granulocyte macrophage-colony stimulating factor (GM-CMF) was detected in OLP samples compared to healthy mucosal tissue. For all cytokines and chemokines investigated, 23 out of 24 comparisons showed a decrease in tendency (significant for IL1β, IL2, IL10, and GM-CSF) in response to plasma treatment. In ex vivo-treated tissue, a decrease of T-cell infiltrate in OLP lesions compared with healthy tissue was observed.

CONCLUSION

Our findings suggest cold physical plasma can be a promising therapeutic option for OLP that requires further validation in vivo.

Gene signatures associated with barrier dysfunction and infection in oral lichen planus identified by analysis of transcriptomic data

Oral lichen planus (OLP) is one of the most prevalent oral mucosal diseases, but there is no cure for OLP yet. The aim of this study was to gain insights into the role of barrier dysfunction and infection in OLP pathogenesis through analysis of transcriptome datasets available in public databases. Two transcriptome datasets were downloaded from the Gene Expression Omnibus database and analyzed as whole and as partial sets after removing outliers. Differentially expressed genes (DEGs) upregulated in the dataset of OLP versus healthy epithelium were significantly enriched in epidermal development, keratinocyte differentiation, keratinization, responses to bacterial infection, and innate immune response. In contrast, the upregulated DEGs in the dataset of the mucosa predominantly reflected chemotaxis of immune cells and inflammatory/immune responses. Forty-three DEGs overlapping in the two datasets were identified after removing outliers from each dataset. The overlapping DEGs included genes associated with hyperkeratosis (upregulated LCE3E and TMEM45A), wound healing (upregulated KRT17, IL36G, TNC, and TGFBI), barrier defects (downregulated FRAS1 and BCL11A), and response to infection (upregulated IL36G, ADAP2, DFNA5, RFTN1, LITAF, and TMEM173). Immunohistochemical examination of IL-36γ, a protein encoded by one of the DEGs IL36G, in control (n = 7) and OLP (n = 25) tissues confirmed the increased expression of IL-36γ in OLP. Collectively, we identified gene signatures associated with hyperkeratosis, wound healing, barrier defects, and response to infection in OLP. IL-36γ, a cytokine involved in both wound repair and antimicrobial defense, may be a possible therapeutic target in OLP.

A proof of concept pilot trial of probiotics in symptomatic oral lichen planus (CABRIO)

OBJECTIVE

To preliminary evaluate the clinical effects of probiotics in individuals with symptomatic oral lichen planus and the possible mechanisms of action.

SUBJECTS AND METHODS

A group of 30 individuals with symptomatic oral lichen planus were recruited in a randomised double-blind parallel group controlled (1:1) proof-of-concept pilot trial of probiotic VSL#3 vs placebo. Efficacy outcomes included changes in pain numeric rating scale, oral disease severity score and the chronic oral mucosal disease questionnaire. Adverse effects, home diary and withdrawals were assessed as feasibility outcomes. Mechanistic outcomes included changes in salivary and serum levels of CXCL10 and IFN-γ and in oral microbial composition.

RESULTS

The probiotic VSL#3 was safe and well tolerated. We observed no statistically significant change in pain, disease activity, quality of life, serum/salivary CXCL10 or oral microbial composition with respect to placebo. Salivary IFN-γ levels demonstrate a trend for a reduced level in the active group (p = 0.082) after 30 days of probiotic consumption.

CONCLUSIONS

The present proof-of-concept study provides some weak not convincing indication of biological and clinical effects of probiotic VSL#3 in individuals with painful oral lichen planus. Further research in this field is needed, with the current study providing useful information to the design of future clinical trials.

Helicobacter pylori infection is correlated with the incidence of erosive oral lichen planus and the alteration of the oral microbiome composition

BACKGROUND

Oral lichen planus (OLP), a common clinical oral disease, is associated with an increased risk of malignant transformation. The mechanism underlying the pathogenesis of OLP is unknown. Oral dysbacteriosis is reported to be one of the aetiological factors of OLP. Although Helicobacter pylori infection is associated with various oral diseases, the correlation between H. pylori infection and OLP is unclear. This study aimed to investigate the effect of H. pylori infection on OLP pathogenesis and oral microbiome composition in the Chinese population, which has a high incidence of H. pylori infection.

RESULT

In this study, saliva samples of 30 patients with OLP (OLP group) and 21 negative controls (NC group) were collected. H. pylori infection was detected using the carbon-13-labeled urea breath test (UBT). The saliva samples were divided into the following four groups based on the H. pylori status: H. pylori-positive OLP (OLP+), H. pylori-positive NC (NC+), H. pylori-negative OLP (OLP-), and H. pylori-negative NC (NC-). Oral microbiome compositions were significantly different between the OLP and NC groups and between the OLP- and OLP+ groups. Compared with those in the OLP- group, those in the OLP+ group had a higher incidence of erosive OLP and higher levels of salivary cytokines. In contrast, the oral microbiome composition and cytokine levels were not significantly different between the NC- and NC+ groups.

CONCLUSIONS

This is the first report to demonstrate that H. pylori infection is significantly correlated with the pathogenesis of erosive OLP.

Study on the Role of Salivary Flora and NF-κB Inflammatory Signal Pathway in Oral Lichen Planus

Oral lichen planus (OLP) is an inflammatory disease. It is believed that infection and immune dysfunction play a key role in its pathogenesis, but the specific mechanism of action remains unclear. The 16s rRNA high-throughput sequencing technique was used to analyze the microbial flora structure in the saliva of OLP patients and healthy controls. The relative abundance of Derxia, Haemophilus, and Pseudomonas in the saliva of the OLP group was lower than that of the healthy control group, but there was no significant difference in the overall structure of the microbial population. In addition, we measured the protein expression levels of toll-like receptor 4 (TLR4) and nuclear factor-kappab p65 (NF-κB p65) in the tissues of OLP patients, and found that there was a significant increase and positive correlation between them (r = 0.907, P = 0.034). The expression levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the OLP group were consistent with those of NF-κB p65. Therefore, we believe that changes in the composition ratio of microbialflora break the original balance state of flora, promote the occurrence of immune inflammatory reaction, and then lead to the generation or aggravation of OLP disease. This discovery provides new ideas for further research on OLP initiation and immune regulation mechanism.

Association between oral lichen planus and systemic conditions and medications: Case-control study

OBJECTIVE

The aim of this study is to investigate the association between oral lichen planus (OLP) and a variety of systemic conditions, medication, and supplement usage.

MATERIALS AND METHOD

A total of 156 patients diagnosed with OLP and 156 controls at Columbia University Irving Medical Center from 2000 to 2013 were selected as part of the matched (1:1) case-control study. Demographics, systemic conditions, prescription medications and supplements were extracted from the patients' medical records. A univariable conditional logistic regression (CLR) analysis was performed to calculate unadjusted odds ratio, to identify significant variables associated with OLP (p < .10). Significant variables were further tested using multivariable CLR analysis with both forward and backward selection to calculate adjusted odds ratio (aOR) and further distinguish variables associated with OLP (p < .05).

RESULTS

This analysis identified six significant variables: thyroid disorder (aOR:5.1,95%CI:2.3-11.2), any form of cancer (aOR:3.4,95%CI:1.4-8.4), type 2 diabetes (aOR:2.8,95%CI:1.2-6.3), hyperlipidemia (aOR:2.3,95%CI:1.3-4.1), oral sedative usage (aOR:6.3,95%CI:1.8-22.5), and vitamin D supplementation (aOR:2.7,95%Cl:1.3-6.0).

CONCLUSION

Thyroid disorders, cancer, type 2 diabetes, hyperlipidemia, sedatives, and vitamin D supplementation were found to be associated with OLP. Additional investigation is required to explore these associations, which could shed light on the potential mechanism of OLP and reinforce the idea that oral lesions could be predicative of previously undetected systemic conditions.

High-level laser therapy versus scalpel surgery in the treatment of oral lichen planus: a randomized control trial

OBJECTIVE

To compare the clinical effectiveness of various types of high-level laser therapy (HLLT) toward scalpel excision for the surgical treatment of erosive oral lichen planus (OLP).

MATERIALS AND METHODS

The total number of 128 individuals were enrolled in the study. The 35 did not meet the inclusion criteria due to malignancy signs and presence of diabetes mellitus. In total, 8 were lost to follow-up, and 10 were excluded from the analysis, due to analgesics intake. This way 75 patients with the erosive form of OLP were analyzed in three intervention groups (Er:YAG, n = 19; Nd:YAG, n = 15; Er:YAG + Nd:YAG combination, n = 20) and one control group with scalpel excision (n = 21). The therapy effectiveness has been assessed based on the comparison of salivary interleukin (IL)-1β, IL-6 and interferon (IFN)-γ preoperative levels to 14, 30 days, and 2 years postoperation, as well as pain level and time of epithelization.

RESULTS

All HLLT groups demonstrated a significantly (p > 0.05) higher IL-1β, IL-6, IFNγ and pain level reduction and quicker epithelization toward the control group on the 30th day, except Nd:YAG in case of IFNγ level. The highest IL-1β, IFNγ and pain level reduction and quicker epithelization on the 30th day was observed in Er:YAG group, followed by Er:YAG + Nd:YAG combination, Nd:YAG respectively. However no significant difference was observed between the HLLT groups with regard to IL-6 level reduction. After a 2-year follow-up, no significant difference was observed between all study groups with regard to all variables.

CONCLUSION

HLLT yields a superior clinical outcome compared to the scalpel excision for the surgical treatment of oral lichen planus, whereby the Er:YAG has been proposed as the most effective laser type at the end of the first postoperative month.

CLINICAL RELEVANCE

For the surgical treatment of erosive OLP the Er:YAG laser may be a preferable treatment option compared to Nd:YAG and scalpel surgery.

TRIAL REGISTRATION

The present trial was registered retrospectively in the German Clinical Trials Register, as a member of WHO international clinical trials registry platform, on the 18.03.2020 with the following number: DRKS00020986.

Interferon-γ activated T-cell IRGM-autophagy axis in oral lichen planus

Oral lichen planus (OLP) is an inflammatory immune disease featured by dense T-cell infiltrate and basal keratinocytes degeneration. Immunity related GTPase M (IRGM) is vital for the induction of autophagy. Our previous studies have demonstrated aberrant autophagy in OLP, however, the involvement of IRGM-autophagy axis in OLP has not yet been revealed. The expression of IRGM and autophagy activity were evaluated in oral mucosal tissues and peripheral T cells of OLP patients and healthy controls, respectively. We found significant upregulation of IRGM and LC3B in lesions of patients with OLP as compared with healthy donors. IRGM, LC3B and NOD2 levels were also elevated in the peripheral T cells of OLP. Then, knockdown of IRGM after electrotransfection with siRNA resulted in attenuated autophagy, growth inhibition, and apoptosis of T cells. In addition, preincubation with IFN-γ promoted the expression of IRGM mRNA and induced autophagy in T cells. Furthermore, IFN-γ decreased the proliferation and apoptosis of T cells, whereas facilitated the viability of keratinocytes in a co-culture system of activated T cells and keratinocytes. Taken together, activated IRGM-autophagy axis under IFN-γ regulation in T cells might participate in the immunoregulatory mechanism of OLP.

T cell-derived exosomes containing cytokines induced keratinocytes apoptosis in oral lichen planus

OBJECTIVE

Oral lichen planus (OLP) is a T cell-mediated inflammatory disease with uncertain etiology. Exosomes are cell-derived vesicles containing biological cargo, being associated with the development of multiple inflammatory diseases. The present study aims to investigate the role of T cell-derived exosomes in the pathogenesis of OLP.

METHODS

Exosomal marker CD63 was detected in OLP lesions by immunohistochemistry. Twenty-three cytokines in T cell-derived exosomes were assessed using luminex xMAP-based assay. After co-incubating with exosomes, the apoptosis of keratinocytes and the proliferation of Jurkat cells were assessed via flow cytometry and cell counting kit-8 assay, respectively.

RESULTS

CD63 was highly expressed in the lymphocyte infiltrated areas of OLP lesions. OLP T cell-derived exosomes contained upregulated interleukin-7, -10, -12, -17 and downregulated interleukin-1β, -5, and interferon-γ. Both exosomes from OLP patients and controls induced the apoptosis of keratinocytes and altered their morphology. Moreover, healthy control-derived exosomes markedly inhibited the proliferation of Jurkat cells, whereas OLP-derived exosomes exhibited no inhibitory effect.

CONCLUSIONS

OLP T cell-derived exosomes have an aberrant cytokine profile and could trigger the apoptosis of keratinocytes in vitro, which may be involved in the pathogenesis of OLP.

Psychological profile and unexpected pain in oral lichen planus: A case-control multicenter SIPMO studya

OBJECTIVES

To analyze psychological profiles, pain, and oral symptoms in patients with oral lichen planus (OLP).

MATERIALS AND METHODS

300 patients with keratotic OLP (K-OLP; reticular, papular, plaque-like subtypes), 300 patients with predominant non-keratotic OLP (nK-OLP; erythematosus atrophic, erosive, ulcerative, bullous subtypes), and 300 controls were recruited in 15 universities. The number of oral sites involved and oral symptoms were recorded. The Numeric Rating Scale (NRS), Total Pain Rating Index (T-PRI), Hamilton Rating Scales for Depression and for Anxiety (HAM-D and HAM-A), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS) were administered.

RESULTS

The OLP patients, especially the nK-OLP, showed higher scores in the NRS, T-PRI, HAM-D, HAM-A and PSQI compared with the controls (p-value < .001** ). A positive correlation between the NRS, T-PRI, HAM-A, HAM-D, and PSQI was found with the number of oral symptoms and number of oral sites involved. Pain was reported in 67.3% of nK-OLP and 49.7% of K-OLP cases with poor correspondence between the site of lesions and the site of the symptoms.

CONCLUSIONS

Mood disorders are frequently associated with OLP with an unexpected symptomatology correlated with the number of oral symptoms and with the extension of disease suggesting a peripheral neuropathy.

Analysis of the Efficacy of Two Treatment Protocols for Patients with Symptomatic Oral Lichen Planus: A Randomized Clinical Trial

Oral lichen planus (OLP) is a chronic, inflammatory, immune-mediated disease, which can alter the quality of life of patients. The aim of this randomized clinical trial was to compare the therapeutic efficacy of clobetasol oral gel 0.05% versus an anti-inflammatory in oral solution (mouthwash) in the management of patients suffering from symptomatic OLP. The secondary objective was to analyze which one of the two treatments induced a greater risk of developing side effects. Forty patients were assigned (20 patients for group), through a randomized design, to receive clobetasol gel 0.05% or an anti-inflammatory mouthwash, which contains calcium hydroxide, hyaluronic acid, umbelliferone and oligomeric pro-anthocyanidins) for three months. At baseline (T0) and after 3 months (T1), patients underwent dental and dermatological examinations to assess their symptoms (Numerical Pain Scale (NRS) score) and signs (Thongprasom score). Data were calculated using T-test for the dependent variable, Wilcoxon test and Mann-Whitney u test. Both clobetasol and anti-inflammatory resulted in a statistically significant reduction of signs, (p < 0.001 and p = 0.02, respectively) and symptoms (p < 0.001 for clobetasol and p = 0.02 for anti-inflammatory). In conclusion, the results evidenced that, compared to clobetasol, the anti-inflammatory was less effective in determining the reduction of signs and symptom in OLP patients.

T cell-derived exosomes induced macrophage inflammatory protein-1α/β drive the trafficking of CD8+ T cells in oral lichen planus

Oral lichen planus (OLP) is a T cell–mediated chronic inflammatory disease with uncertain aetiology. Exosomes are nanosized particles with biological capacities. Here, we aimed to study the effects of T cell–derived exosomes (T‐exos) on the pathogenesis of OLP and its mechanism. T‐exos were incubated with Jurkat cells for 48 hours, and 26 cytokines in the supernatant were measured by luminex assay. The expression of macrophage inflammatory protein (MIP)‐1α/β was detected using immunohistochemistry and ELISA; that of CCR1/3/5 on peripheral T cells was determined by flow cytometry. Transwell assay was performed to investigate the chemotactic effect of MIP‐1α/β, and cells in the lower chambers were examinated by flow cytometry. As a result, OLP T‐exos elevated the production of MIP‐1α/β, which were highly expressed in OLP tissues and plasma. CCR1/5 were markedly expressed on OLP peripheral T cells, and the majority of CCR1/5⁺ T cells were CD8⁺ T cells. Besides, MIP‐1α/β promoted the migration of OLP mononuclear cells, while inhibiting CCR1/5 significantly decreased the trafficking of mononuclear cells, especially that of CD8⁺ T cells. Conclusively, OLP T‐exos‐induced MIP‐1α/β may drive the trafficking of CD8⁺ T cells after binding with CCR1/5 in OLP, contributing to the development of OLP.

Interleukin 4 Affects Epilepsy by Regulating Glial Cells: Potential and Possible Mechanism

Epilepsy is a chronic brain dysfunction induced by an abnormal neuronal discharge that is caused by complicated psychopathologies. Recently, accumulating studies have revealed a close relationship between inflammation and epilepsy. Specifically, microglia and astrocytes are important inflammatory cells in the central nervous system (CNS) that have been proven to be related to the pathogenesis and development of epilepsy. Additionally, interleukin 4 (IL-4) is an anti-inflammatory factor that can regulate microglia and astrocytes in many aspects. This review article focuses on the regulatory role of IL-4 in the pathological changes of glial cells related to epilepsy. We additionally propose that IL-4 may play a protective role in epileptogenesis and suggest that IL-4 may be a novel therapeutic target for the treatment of epilepsy.

Omega-3 polyunsaturated fatty acids: a promising approach for the management of oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a T-cell-mediated inflammatory disease with a risk of malignant transformation. Although the etiology of OLP is still uncertain, growing evidence suggests that oral microbiota, antigen-specific, and non-specific mechanisms are involved in the pathogenesis of OLP. Antigen-specific mechanisms include antigen presentation, T-cell activation, nuclear factor-kappa B signaling pathway, and cytokine secretion, while non-specific mechanisms consist of matrix metalloproteinases (MMP)-9 upregulation, psychological pressure, oxidative damage, aberrant expression of microRNAs (miRNAs), and autophagy. Till now, there is no cure for OLP, and the main purpose of OLP therapy is symptomatic control.

FINDING

Seafood and its derivative omega-3 polyunsaturated fatty acids (n-3 PUFAs) can suppress antigen presentation, T-cell activation, and nuclear factor-kappa B signaling pathway, modulate the overexpressed inflammatory cytokines, inhibit the expression of MMP-9, as well as regulate the expression of miRNAs and autophagy. And they are possible agents for ameliorating psychological disorder and oxidative damage. Moreover, n-3 PUFAs supplementation has a beneficial effect on preventing tumorigenesis.

CONCLUSION

n-3 PUFAs consumption may provide a non-toxic, inexpensive administration for OLP.

Altered expression of CCN1 in oral lichen planus associated with keratinocyte activation and IL-1β, ICAM1, and CCL5 up-regulation

BACKGROUND

Emerging evidence indicates that CCN1 is a novel inflammation-regulated mediator involved in the pathogenesis of some immune-mediated inflammatory diseases. The objective of this study was to investigate the preliminary roles of CCN1 and its related cytokines IL-1β, CCL5, and ICAM1 in oral lichen planus (OLP).

METHODS

CCN1 expression levels in biopsies from OLP patients against normal oral mucosa (NOM) using immunohistochemistry (42 OLP vs 9 NOM) and RT-qPCR (20 OLP vs 20 NOM) were compared, respectively. The correlation of CCN1 and IL-1β, CCL5, and ICAM1 expression was examined by RT-qPCR in tissue samples and an in vitro cell culture system using keratinocyte HaCaT cells incubated with lipopolysaccharides.

RESULTS

Immunohistochemistry showed that CCN1 protein mainly expressed in the cytoplasm of epithelial keratinocytes of OLP. Consistently, RT-qPCR revealed that mRNA expression of CCN1 was increased in OLP compared with NOM (P < .05) and positively correlated with the high expression of IL-1β, ICAM1, and CCL5 (P < .001), respectively. Importantly, an in vitro study showed that keratinocyte proliferation significantly (P < .05) increased by CCN1 stimulation. Moreover, IL-1β, ICAM1, and CCL5 expression in keratinocytes stimulated by CCN1 was increased (P < .05), respectively.

CONCLUSIONS

This preliminary study for the first time reported that altered expression of CCN1 was associated with high expression of IL-1β, ICAM1, and CCL5 in OLP. And we demonstrated CCN1 promoted keratinocyte activation, as well as IL-1β, ICAM1, and CCL5 production in keratinocytes. Our data indicated that the potential role of CCN1 and its related cytokines was involved in the pathogenesis of OLP.

Salivary Biomarkers and Their Application in the Diagnosis and Monitoring of the Most Common Oral Pathologies

Saliva is a highly versatile biological fluid that is easy to gather in a non-invasive manner—and the results of its analysis complement clinical and histopathological findings in the diagnosis of multiple diseases. The objective of this review was to offer an update on the contribution of salivary biomarkers to the diagnosis and prognosis of diseases of the oral cavity, including oral lichen planus, periodontitis, Sjögren’s syndrome, oral leukoplakia, peri-implantitis, and medication-related osteonecrosis of the jaw. Salivary biomarkers such as interleukins, growth factors, enzymes, and other biomolecules have proven useful in the diagnosis and follow-up of these diseases, facilitating the early evaluation of malignization risk and the monitoring of disease progression and response to treatment. However, further studies are required to identify new biomarkers and verify their reported role in the diagnosis and/or prognosis of oral diseases.

Receptor and signaling pathway involved in bovine lymphocyte activation by Atractylodis macrocephalae polysaccharides

The present study was to investigate the molecular mechanism underlying lymphocyte activation by total polysaccharides from Atractylodis macrocephalae (RAMPtp). The results showed that RAMPtp significantly promoted the secretions of cytokines (IFN-γ, IL-1α, IL-21, IFN-α, CCL4, CXCL9 and CXCL10), increased the proportions of CD4⁺ and CD8⁺ subpopulations, and enhanced the expressions of c-JUN, NFAT4, STAT1 and STAT3. microRNA sequencing identified 67 differentially expressed miRNAs (DEMs) in RAMPtp-stimulated SMLN lymphocytes, including 55 up-regulated and 12 down-regulated. GO and KEGG enrichment analyses of the predicted DEMs-targeted genes indicated that they were associated with immune system pathways, including PI3K-Akt, MAPKs, Jak-STAT and Calcium signaling pathways, which were confirmed by western blot and pathway inhibition assays. RAMPtp was further observed to favor immunostimulatory effect on both T and B lymphocytes via binding to TCR and membrane Ig individually. These findings might explain the immunomodulatory mechanism of RAMPtp in ameliorating the bovine intramammary infection.

Inflammatory Biomarkers, Microbiome, Depression, and Executive Dysfunction in Alcohol Users

Alcohol-related disorders (ARD) are highly prevalent among Latin American-Caribbean countries. Mental disorders are common comorbidities in individuals with ARD. However, the etiology of the association between ARD and mental disorders remains unclear. We examined the association of inflammatory cytokines, microbiome, and other biomakers with measures of depression, social anxiety, and executive functions. We observed a significant increase in cytokine and chemokine expression levels in saliva and plasma in the alcohol group (AG) samples. Also, the salivary bacterial composition in the AG revealed an abundance of Prevotella. Depression symptomatology was markedly higher in the AG, but social anxiety levels were negligible. AG also exhibited executive dysfunctions, which negatively correlated with increased plasma levels of pro-inflammatory cytokines and increased salivary concentrations of Prevotella bacteria. Our study suggests that chronic alcohol use correlates with executive dysfunction, immune system dysregulation, and dysbiosis of the salivary microbiota. Additional studies are needed to understand the role of the microbiome and inflammation in alcohol use and mental comorbidities.

Lichen planus: Oral manifestations, differential diagnosis and treatment

Introduction: Some of the typical skin diseases, such as Pemphigus vulgaris, Pemphigoid mucosae oris, Erythema exudativum multiforme, Sclerodremia, Dermatitis herpetiformis-Duhring and Lichen planus, can cause swelling and irritation in mucous membranes of the oral cavity. Aim: The aim of the study was to precise diagnosis and treatment of oral Lichen planus manifestations. Methods: Analyzing the literature data and the experience of clinicians, the most common oral lichen planus manifestations were investigated. Results: This disease most commonly occurs in middle-aged patients (30-60 years) and is more common in women than in men. Oral Lichen planus is rarely seen in children. The disease presents in 0.5% to 2% of the population. Clinical history established the relation between oral Lichen planus and oral carcinoma, and therefore this disease should be considered a precancerous lesion. Conclusion: Dermatoses in the mouth are localized most often in the oral mucosa, both at the height of the occlusal line and in the mucous membrane of the retromolar area, but they can also occur in the mucous membranes of the tongue, the floor of the mouth and lips.

Roles of the matricellular protein Tenascin-C in T-lymphocyte trafficking and etiopathogenesis of Oral Lichen Planus

OBJECTIVE

This study was aimed at examining the role of Tenascin-C in T cell trafficking in Oral Lichen Planus (OLP).

DESIGN

For the in vivo immunohistochemical analyses, 115 OLP samples were collected from patients and immunostaining was performed. The intensity and distribution of TN-C expression were quantified and correlated with histological analyses of basement membrane integrity and presence of inflammatory infiltrate. For the in vitro study, TN-C and collagen were coated on culture plates and migration of T lymphocytes was assessed.

RESULTS

TN-C immunoexpression was increased in terms of both distribution and intensity along the basement membrane zone. These changes were significantly associated with basement membrane duplication (distribution p < 0.002 and intensity p < 0.001) and bands of inflammation (distribution p < 0.002 and intensity p < 0.001) assessed by Chi-square test. T lymphocytes demonstrated significant migration towards TN-C as compared to collagen (n = 3, p < 0.05).

CONCLUSIONS

These findings indicate TN-C may have a key role in promoting T cell migration at the epithelial-mesenchymal junction in OLP. These observations suggest TN-C could be a good target for therapeutic intervention, either in itself or synergistically with anti-inflammatory directed strategies in this chronic disease management.

Epidemiologic and Clinical Differences Between Classic and Hypertrophic Lichen Planus in Nigeria

Introduction. Lichen planus is a chronic inflammatory skin disease known to have several clinical variants with attended variable clinical outcomes. Certain complications have been observed in the hypertrophic type, which were not found in association with the classic variant.

Objective: To identify the epidemiologic and clinical differences between the classic and hypertrophic lichen planus and clinical correlates.

Material and Methods. Of 104 participants with lichen planus included in the study, 49 had classic and 55 hypertrophic lichen planus. Demographic and clinical information was obtained. Diagnosis of lichen planus was made clinically and confirmed with histology. The participants were screened for metabolic syndrome, hepatitis B, and C.

Results: Mean age of all patients was 37.20±13.39 years, with no age and gender differences between the participants with classic and hypertrophic lichen planus. Classic lichen planus was more likely to be painful, (8.2% vs 0.0, p=0.046), generalized (95.9% vs 16.4%, p<0.001), involve the oral mucosa (38.8% vs 0.0, p<0.001), the nails (38.8% vs 1.8, p<0.001), present with kobnerisation (55.1% vs 5.5%,<0.001), Wickhiam striae (69.4% vs 16.4%, p<0.001), associated with Hepatitis B vaccination (16.3% vs 3.6%, p<0.028) and anti HCV positivity (16.3% vs 0.0%, p=0.002). Hypertrophic lichen planus was significantly associated with impaired glucose tolerance/diabetes mellitus (16.4% vs 2.0%, p=0.013), dyslipidemia (74.5% vs 40.8%, p=0.001) and saw-tooth histologic appearance compared to classic type.

Conclusion: Hypertrophic lichen planus is more likely to be associated with metabolic complications compared to the classic type. Further studies are needed to loink this difference t chronic inflamation.

Anti-inflammatory effect of paeoniflorin combined with baicalin in oral inflammatory diseases

OBJECTIVE

There are challenges in the treatment of chronic inflammatory diseases of oral mucosa. Both paeoniflorin (PF) and baicalin (BAI) exert anti-inflammatory effects, but the mechanism underlying their combined effects is still unclear. Here, we explored the anti-inflammatory function of the PF-BAI combination in the oral inflammatory response.

MATERIALS AND METHODS

The CCK-8 assay was used to determine the proliferative capacity of HOKs with PF and BAI. Enzyme-linked immunosorbent (ELISA), Western blotting, reverse transcription polymerase chain reaction, and confocal immunofluorescence were performed to study the anti-inflammatory effects of PF-BAI in LPS-stimulated human oral keratinocytes (HOKs). Immunohistochemistry and ELISA were performed to detect the levels of NF-κB p65, IKKα and IL-6, TNF-α in OLP and healthy tissues.

RESULTS

Compared to PF or BAI alone, the combination of PF-BAI at 5 µg/ml downregulated secretion of inflammatory cytokines more effectively (p < .05). Combined PF-BAI decreased NF-κB p65 and IκBα protein phosphorylation, leading to reduce nuclear translocation of NF-κB p65. Higher expression of TNF-α, IL-6, NF-κB p65, and IKKα were observed in OLP than in HC tissues (p < .01).

CONCLUSION

The optimal combination concentration of PF and BAI at 5 µg/ml may have a positive effect on the treatment of oral inflammatory diseases, providing a novel therapeutic approach.

Oral lichen planus and thyroid gland diseases: possible associations

Background

Lichen planus (LP) is a chronic inflammatory mucocutaneous disease that commonly affects the oral cavity. Previous reports have suggested a possible association between LP and thyroid gland diseases (TGDs). The purpose of this study was to investigate possible associations between oral lichen planus (OLP) and TGDs.

Methods

Patients diagnosed with OLP, both clinically and histopathologically (N = 102), were classified according to clinical course (symptomatic/asymptomatic), type (reticular/plaque, atrophic and erosive) and location of lesions. Data on TGDs was compared to age- and gender-matched controls (N = 102) without OLP. Diagnosis of any type of TGD and related medication for study and control groups was recorded from the medical files provided by patients’ physicians. Statistical analysis used Student’s t-test and Fisher’s exact test; significance was set at p < 0.05.

Results

TGDs (all), hypothyroidism and related medications were found in 16.6, 12.7 and 12.7% of patients with OLP, respectively. These findings were similar to the control group: TGDs (all) -15.7%, hypothyroidism - 9.8% and thyroid gland disease-related medication - 9.8% (p > 0.05). No significant associations were found between different characteristics of OLP and hypothyroidism or other TGD (p > 0.05).

Conclusions

We found no significant associations between the co-existence of OLP and TGD or related-medications. Our findings are in agreement with some of the previously published similar studies but in controversy with others. Further well-designed, multicenter studies with large groups of patients and controls may help to establish the nature of the associations between OLP and TGDs.

Possible treatment for cutaneous lichen planus: An in vitro anti-inflammatory role of Angelica polysaccharide in human keratinocytes HaCaT

Cutaneous lichen planus (CLP) is an autoimmune disease. Angelica polysaccharide (AP) has been found to exert immunomodulation activity. In this study, we explored the roles of AP in lipopolysaccharide (LPS)-induced inflammatory injury of human keratinocytes (HaCaT cells), as well as the underlying mechanisms. LPS-induced cell injury was evaluated by alterations of cell viability, apoptosis, and expressions of proteins associated with apoptosis and inflammatory cytokines. Then, the protective effects of AP on LPS-induced cell injury were assessed. The protein expressions of sirtuin 1 (SIRT1) and key kinases in the Nrf2/HO-1 and nuclear factor κB (NF-κB) pathways were measured using western blotting. SIRT1 knockdown and overexpression were used to analyze whether AP affected HaCaT cells through regulating SIRT1. Finally, the possible inhibitory effects of AP on cell injury after LPS treatment were also evaluated. We found that LPS reduced HaCaT cell viability, enhanced apoptosis, and induced release of inflammatory cytokines. AP alleviated LPS-induced HaCaT cell inflammatory injury. The expression of SIRT1 was enhanced after AP treatment. AP activated Nrf2/HO-1 pathway while inhibited NF-κB pathway in HaCaT cells. The protective effects of AP on LPS-induced HaCaT cell injury were reversed by SIRT1 knockdown. Dysregulation of SIRT1 altered the activation of Nrf2/HO-1 and NF-κB pathways in LPS-treated HaCaT cells. Furthermore, AP also exerted inhibitory effects on HaCaT cell injury after LPS stimulation. In conclusion, AP could alleviate LPS-induced inflammatory injury of HaCaT cells through upregulating SIRT1 expression and then activating Nrf2/HO-1 pathway but inactivating NF-κB pathway. This study provided a possible therapeutic strategy for clinical CLP treatments.

CD146 expression in oral lichen planus and oral cancer

OBJECTIVE

To examine the CD146/METCAM expression on keratinocytes in normal oral mucosa (NOM), oral lichen planus (OLP), oral epithelial dysplasia (OED), and oral squamous cell carcinoma (OSCC).

SUBJECTS AND METHODS

Immunohistochemical examination of CD146 was performed on 80 specimens, divided into 20 cases from each group. The number of CD146⁺ keratinocytes was quantitatively assessed together with the staining intensity.

RESULTS

The mean percentage of CD146⁺ keratinocytes was 19.04±15.32, 59.40±24.48, 60.04±28.87, and 22.13±21.03 in NOM, OLP, OED, and OSCC, respectively. The mean percentages of CD146⁺ keratinocytes in OLP and OED were significantly higher than those of NOM and OSCC (p≤0.001). Most OED (55%) and OLP (60%) showed strong and moderate staining intensity, respectively, while NOM (50%) and OSCC (45%) predominantly expressed CD146 at mild intensity.

CONCLUSIONS

This is the first study to examine CD146 expression in OLP and OED. CD146 is upregulated in OLP and OED but downregulated in OSCC. The alteration in CD146 may be involved in the immunoregulatory response of OLP and the early event of oral carcinogenesis. The loss of this protein may underlie the progression of OED into invasive OSCC.

CLINICAL RELEVANCE

Overexpression of CD146 protein may play a role in the pathophysiology of OLP and OED.

Assessment of Interleukin-18 gene polymorphism and serum levels in oral lichen planus in an Indian population

BACKGROUND

Oral lichen planus (OLP) is a chronic, inflammatory disease with uncertain etiology. The aim of this study was to assess Interleukin-18 (IL-18) gene polymorphism and serum levels in OLP cases of Indian origin and to compare them with a control population of similar background.

METHODS

The assessment of single-nucleotide polymorphisms (SNPs) of IL-18 gene at promoter regions -137(G/C) and -607(C/A) was done in 70 OLP cases and 70 healthy controls using sequence-specific primer-polymerase chain reaction (SSP-PCR). In a subset of this cohort, comprising of 41 OLP cases and 41 controls, serum IL-18 levels were assessed using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Mean serum levels of IL-18 among OLP cases were significantly higher when compared to controls. Genotypic and allelic frequencies of IL-18 at position -137(G/C) showed that GG genotype and allele G was significantly higher in OLP cases, whereas, GC genotype and C allele was high in the control group. Polymorphism of IL-18 at position -607(C/A) showed no significant differences.

CONCLUSIONS

Gene polymorphism at -137GG genotype and allele G seems to be associated with genetic susceptibility to OLP whereas -137GC and allele C may have a protective role against its development. However, our study lacks clear statistical correlation, the differences observed could be caused by sampling problems and the results could not be fully representative of Indian patients with OLP. Further studies are warranted to explore the role of IL-18 genetic polymorphisms in OLP development.

Immunohistochemical and clinical significance of matrix metalloproteinase-2 and its inhibitor in oral lichen planus

Background:

Matrix metalloproteinases (MMP) are being considered important mediators in cancer invasion, and plenty of research is in progress. Our objective was to evaluate the presence of MMP-2 and tissue inhibitor of metalloproteinase (TIMP-2) in oral lichen planus (OLP) and to assess its role in the pathogenesis of OLP and as an indicator of malignant transformation.

Materials and Methods:

Immunohistochemical analysis for MMP-2 and TIMP-2 was performed in thirty histopathologically confirmed, formalin-fixed, paraffin-embedded specimens of OLP (24 cases of reticular and 6 cases of erosive LP). A semi-quantitative analysis was done to assess the expression and distribution of this marker in these lesions.

Results:

In all cases of OLP, MMP-2 expression was seen mainly in areas of lymphocytic inflammatory infiltrate (100%) in the lamina propria within the overlying epithelium. TIMP-2 expression was seen more than 50% in the fibroblasts and basal and parabasal cells.

Conclusion:

The expression of MMP-2 and TIMP-2 was observed in all cases of OLP. However, a clinical 5-year follow-up of the lesion revealed no progression of the disease except for chronic exacerbation and regression of these lesions. Although our study considers MMP-2 and TIMP-2 as mediators in the pathogenesis of OLP, it still remains debatable whether they have a direct role to play in the disease process or whether they are suitable biomarkers to assess the disease progression.

Oral lichen-planus-associated fibroblasts acquire myofibroblast characteristics and secrete pro-inflammatory cytokines in response to Porphyromonas gingivalis lipopolysaccharide stimulation

Background

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease in which comprehensive inflammation-related cytokines are involved. These cytokines are commonly produced by immune cells and specific nonimmune cells including keratinocytes, endothelial cells and fibroblasts. This raises the question of whether fibroblasts in OLP lesions contribute to the inflammatory process upon inflammatory simulation.

Methods

Primary cultured Oral lichen-planus-associated fibroblasts (OLP AFs, n = 5) and normal buccal mucosal fibroblasts (NFs, n = 5) were examined by immunohistochemistry, Western blotting and reverse transcription-polymerase chain reactions (RT-PCR). Various inflammatory mediators were evaluated with a multiplex assay. Differences among groups were assessed using a Student’s test or repeated measures one-way ANOVA, as appropriate.

Results

OLP AFs express significantly higher levels of α-smooth muscle actin (α-SMA) than NFs, indicating the presence of myofibroblasts. Myofibroblasts secrete Interleukin (IL)-6, IL-8, and tumor necrosis factor-α (TNF-α) in response to Porphyromonas gingivalis lipopolysaccharide (pg. LPS).

Conclusion

OLP AFs demonstrated α-SMA expression and secreted pro-inflammatory cytokines in response to pg. LPS stimulation.

Electronic supplementary material

The online version of this article (10.1186/s12903-018-0656-6) contains supplementary material, which is available to authorized users.

Potential pathogenic mechanisms involved in the association between lichen planus and hepatitis C virus infection

Lichen planus (LP) is an immune-mediated inflammatory disease that particularly affects the skin and mucous membranes. Its etiology remains elusive, however some trigger factors, including viral or bacterial antigens, drugs and metals, have been postulated. There is a higher prevalence of hepatitis C virus (HCV) infection among patients with LP, with some geographical variations. HCV is an enveloped RNA virus that belongs to the Flaviviridae family and in most instances causes chronic liver infections. It has been hypothesized that HCV may contribute to LP development, but the link between the two disorders is not fully understood. It is still debatable whether HCV leads to the occurrence of LP lesions directly by replication inside the infected cells or indirectly by activating immunological pathways. Molecular studies have revealed HCV RNA in specimens collected from patients with LP. The autoimmune theory was also suggested given that several studies have revealed viral replication and immune response activation associated with autoantibody synthesis. The aim of this review is to summarize the main potential mechanisms involved in the association between LP and HCV infection. Understanding the link between the two disorders may shed some light on the pathogenesis of LP, which is a challenging issue.

Aberrant histone modification and inflammatory cytokine production of peripheral CD4+ T cells in patients with oral lichen planus

Backgrounds

To investigate alterations in histone modification and histone deacetylases (HDACs) in patients with oral lichen planus (OLP), and to evaluate correlations with inflammatory cytokine production.

Methods

Global histone H3/H4 acetylation and HDAC activity in CD4+ T cells from 23 patients with OLP and 10 healthy control subjects were examined using spectrophotometry. The mRNA levels of eight members of four classes of HDAC genes were measured by real‐time quantitative polymerase chain reaction. Forty cytokines involved in inflammation were examined with a cytokine array. The correlation between histone modification and cytokine production was analyzed.

Results

Global histone H3 hypo‐acetylation was observed in OLP patients. Patients with OLP had significantly higher HDACs activity,and higher HDAC6 and HDAC7 mRNA level compared with the controls. Of the 40 cytokines in the cytokine array, eight were significantly increased in OLP patients: interleukin (IL)‐4, IL‐8, IL‐1ra, tumor necrosis factor receptor II (TNFR II), macrophage inflammatory protein 1b (MIP‐1b), fibrosis‐associated tissue inhibitors of metalloproteinase 1 (TIMP)‐1, monocyte chemotactic protein 1 (MCP‐1), and eotaxin‐2. In the OLP group, the acetylation level of histone H3 was negatively correlated with IL‐4 and MCP‐1 production, and the expression of HDAC6 mRNA was positively correlated with MCP‐1 production. In the non‐erosive subgroup, acetylation of histone H3 was negatively correlated with IL‐4, IL‐16, and TIMP‐2 production. In the erosive OLP subgroup, the expression of HDAC7 mRNA was positively correlated with MIP‐1a production.

Conclusion

Aberrant histone modification of CD4+ T cells in peripheral blood could occur in OLP patients, and possibly affects inflammatory cytokine production.

Black pepper and its bioactive constituent piperine: promising therapeutic strategies for oral lichen planus

Oral lichen planus (OLP) is a common T cell-mediated chronic inflammatory disease with malignant potential and unclear etiology. The present study suggests that antigen-specific mechanisms in which dentritic cells, T lymphocytes and NF-κB signaling pathway play critical roles, are involved in the pathogenesis of OLP. Additionally, it has been indicated that altered expression of cyclooxygenase 2 (COX-2) and imbalanced oxidant-antioxidant status as well as psychological issue may act as promoters to the development of OLP. Therapies for OLP are primarily aimed to control symptoms and a specific cure is not yet available. Black pepper and its principle bioactive compound piperine have been reported to possess remarkable pharmacological activities. Not only has piperine been evidenced to exhibit repressive effects on the maturation of dentritic cells, the proliferation, activation and function of T lymphocytes as well as the NF-κB signaling pathway, but also to suppress the overproduction of COX-2 and weaken the oxidative stress. Furthermore, piperine might be a possible agent for alleviating psychological disorders and preventing carcinogenesis. Given all these into consideration, piperine may be a novel and effective therapeutic strategy for OLP.

Efficacy of photobiomodulation on oral lichen planus: a protocol study for a double-blind, randomised controlled clinical trial

INTRODUCTION

Oral lichen planus (OLP) is an idiopathic chronic mucocutaneous disease with a wide range of clinical manifestations, including white reticular patches, erosive/ulcerative and atrophic lesions, both associated with intense symptomatology. Topical corticosteroids are commonly used as standard therapy. However, patients frequently present relapses after the discontinuation of treatment as well as developing resistance to corticosteroid therapy. Photobiomodulation (PBM) has been shown to be a potential therapeutic tool to treat inflammatory disorders, including OLP. The aim of this study was to compare the efficacy of PBM (660 nm) with corticosteroid therapy with clobetasol propionate 0.05% for the treatment of OLP.

METHODS AND ANALYSIS

Forty-four patients with symptomatic and histopathological diagnosis of OLP will be randomised into two experimental groups in a double-blind manner: control group (n=22): clobetasol propionate 0.05%+placebo PBM, and experimental group (n=22): PBM (λ=660 nm, power 100 mW, radiant exposure: 177 J/cm² and 0.5J per point)+placebo gel. Laser will be applied 2×/week for 1 month and clobetasol propionate three times a day for 30 days and the same for placebo treatments. The primary variable (pain) and the secondary variables (clinical score, evaluation of functional scores, clinical resolution, OLP recurrence, quality of life and anxiety and depression) will be evaluated at the baseline, once a week during treatment (depending on the variables) and after 30 days and 60 days of follow-up. Pain will be evaluated using visual analogue scale and clinical characteristics will be scored using the Thongprasom Index. The quality of life and anxiety and depression will be evaluated by Oral Health Impact Profile-14 questionnaire and by Hospital Anxiety and Depression Scale for anxiety scale, respectively. The serum and salivary levels of interleukin (IL)-6, IL-10, IL-1β, INF-γ and tumour necrosis factor-α will be evaluated by ELISA at baseline and at the end of treatment.

ETHICS AND DISSEMINATION

This protocol was approved (#2.375.410) by the Nove de Julho University (UNINOVE) Research Ethics Committee. The data gathered using this protocol will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT03320460.

Interferon gamma and interleukin 8 gene polymorphisms in patients with hepatitis C virus related oral lichen planus

OBJECTIVES

This study aimed to determine the association of rs2430561 and rs4073 polymorphisms in the Interferon gamma (IFN-ɤ) and Interleukin 8 (IL-8) genes, respectively, with hepatitis C virus-related oral lichen planus and disease severity.

DESIGN

This is a case-control study. 60 subjects were equally divided into patients with and without oral lichen planus. They were further subdivided into hepatitis C virus seropositive and seronegative patients. All patients were genotyped for IFN-γ rs2430561 thymine to adenine (T > A) and IL-8 rs4073 adenine to thymine (A > T) polymorphisms. All patients with oral lichen planus had their lesions measured and documented using the Escudier scoring system.

RESULTS

Disease activity was significantly higher in the "oral lichen planus/hepatitis C virus-positive" patients than in the "oral lichen planus/hepatitis C virus-negative" patients (P = 0.003). IFN-γ rs2430561 T > A and IL-8 rs4073 A > T genotypes and allele frequencies were not associated with the oral lichen planus group or the normal group. Stratification of the two groups into HCV and non-HCV-infected patients or into erosive and non-erosive types revealed no significant associations. The "A-allele-containing" genotypes of IL-8 rs4073 A > T were significantly more prevalent in the patients with oral lichen planus than in those without.

CONCLUSION

Hepatitis C virus infection is associated with the development of erosive oral lichen planus. The A-allele of IL-8 rs4073 A > T may have a role in the development and progression of oral lichen planus.

Myofibroblasts in oral potentially malignant disorders: Is it related to malignant transformation?

In oral cancer, acquisition of α-smooth muscle actin (α-SMA)-positive fibroblasts, known as myofibroblasts or carcinoma-associated fibroblasts (CAF), is an important event for progression and metastasis. However, the contribution of myofibroblasts in oral potentially malignant disorders (OPMD) remains controversial. This systematic review provides evidence that immunodetection of myofibroblasts may identify oral submucous fibrosis (OSMF) with high risk of malignant transformation, but does not represent an auxiliary tool to predict the malignant potential of leukoplakia and erythroplakia, the most common OPMD.

Cytokines, cortisol, and nitric oxide as salivary biomarkers in oral lichen planus: a systematic review

The etiopathogenesis of oral lichen planus (OLP) is still not fully elucidated, and it is believed that its development could involve a neuro-immune-endocrine profile. This systematic review investigated the relationship between cytokines, cortisol, and nitric oxide (NO) in the saliva of OLP patients. An electronic search was conducted in Pubmed/Medline, Scopus, LIVIVO, and Web of Science databases with no restriction of language to identify studies published up to December 2017. Data extraction was performed using the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. A total of 140 articles were retrieved, and 32 articles fulfilled the inclusion criteria (cytokines = 17; cortisol = 9; NO = 6). The most studied cytokines in the saliva of OLP patients were interleukins IL-4, IL-6, IL-8, IFN-ү, and TNF-α, which were higher in OLP patients than in healthy controls (HC). Salivary cortisol was found to be higher in OLP than in HC in most (55.5%) of the selected studies, and all studies related to NO found higher levels of this marker in OLP than in HC. Despite controversial results, our review suggests that OLP patients have an increased inflammatory response, as indicated by the proinflammatory profile of salivary cytokines. In addition, we conclude that salivary cytokine and NO measurements may have significant diagnostic and prognostic potential for monitoring disease activity and therapeutic responses in OLP.

The Measurement of Serum Tumor Necrosis Factor-alpha Levels in Patients with Lichen Planus

Background:

Lichen planus is a common mucocutaneous inflammatory skin disease with a multifactorial etiology. Cytokines have a key role in its pathogenesis. In our study, we aimed to investigate the relationship between the disease severity and levels of the tumor necrosis factor alpha (TNF-α) cytokine which was considered as a primary cytokine that initiates the cytotoxicity.

Materials and Methods:

A total of 34 patients with lichen planus who were 18 year or older and gender-matched healthy controls were included in the study. Serum TNF-α levels were measured by human TNF-α enzyme-linked immunosorbent assay test kits and the values in the two groups were statistically compared.

Results:

The mean serum TNF-α levels were higher in the patient group than that in the control group. Serum TNF-α levels were not associated with oral mucosal involvement and gender. However, it was observed that the level of TNF-α was higher in older ages, both in patient and in control groups.

Conclusion:

It is thought that TNF-α, a proinflammatory cytokine, may have an important role in the pathogenesis of lichen planus.

Increased expression of p16 in both oral and genital lichen planus

Background

Lichen Planus, LP, is an inflammatory disease of possible autoimmune origin affecting mainly oral and genital mucosa and skin. According to the WHO oral LP is considered a potentially malignant disorders. The p16 tumour suppressor protein can act as an inhibitor of cyclin dependent kinases 4 and 6 and thus down regulate cell cycle progression. Since the discovery of p16 several studies have evaluated its expression in various forms of human cancers. The aim of this study was to evaluate and compare the expression of p16 in oral and genital LP and corresponding healthy mucosa.

Material and Methods

A total of 76 cases of oral LP (OLP), 34 cases of genital LP (GLP), 12 cases of healthy oral and 9 cases of healthy genital mucosa were analysed by the use of immunohistochemistry.

Results

Data showed p16 to be highly expressed in both oral and genital LP, higher than in oral (p=0.000), and genital controls (p=0.002).

Conclusions

Results suggest that the over-expression of p16 seen in LP play a part in the histopathology of the disease.

Key words:p16, inflammation, oral, genital, lichen planus, malignant risk.