The roles of matrix metalloproteinases-2, -7, -10 and tissue inhibitor of metalloproteinase-1 in the pathogenesis of oral lichen planus

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.

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.

The immunopathogenesis of oral lichen planus-Is there a role for mucosal associated invariant T cells?

Oral lichen planus (OLP) is a chronic, T-cell-mediated, immune condition of unknown cause. OLP may present with painful symptoms requiring treatment, as well as lesions outside the oral cavity. It is likely that what initiates the OLP disease process is a complex interaction of host susceptibility and environmental triggers. While it is possible that OLP represents a true autoimmune condition against an epithelial autoantigen, the mechanisms that lead to this immune dysregulation are still poorly understood. In this review article, we discuss current concepts relating to the immunopathogenesis of OLP, as well as the potential contributory roles the oral microbiota and mucosal-associated invariant T (MAIT) cells.

Salivary MMP-1, MMP-2, MMP-3 and MMP-13 Levels in Patients with Oral Lichen Planus and Squamous Cell Carcinoma

The aim of present study was to evaluate salivary matrix metalloproteinase-1 (MMP-1), MMP-2, MMP-3 and MMP-13 levels in patients with oral lichen planus (OLP) and squamous cell carcinomas (SCC) as well as in healthy controls. Thirty cases of OLP (bilateral lesions, papular and reticular lesions, and Wickham lines) clinically and histopathologically (group A), 30 with oral SCCs (group B), and 30 with no history of oral cancer, other lesions or lichen planus (group C) were enrolled at the Department of Oral Medicine School of Dentistry, Zahedan, Iran. Unstimulated whole saliva was collected and laboratory measurement of salivary concentration of MMP-1, MMP-2, MMP-3 and MMP-13 was conducted by immuno-sorbent enzyme-linked methods. Data analysis was performed with Kruskal-Wallis and Mann-Whitney tests and Pearson’s correlation coefficients. In the present study, MMP-2 and MMP-13 levels were higher in oral SCC patients than in OLP and healthy individuals. More research is required to assess MMP links with tumor invasion.

Oral lichen planus: a literature review and update

Lichen planus (LP) is a common chronic inflammatory condition that can affect skin and mucous membranes, including the oral mucosa. Because of the anatomic, physiologic and functional peculiarities of the oral cavity, the oral variant of LP (OLP) requires specific evaluations in terms of diagnosis and management. In this comprehensive review, we discuss the current developments in the understanding of the etiopathogenesis, clinical-pathologic presentation, and treatment of OLP, and provide follow-up recommendations informed by recent data on the malignant potential of the disease as well as health economics evaluations.

miR-125b inhibits keratinocyte proliferation and promotes keratinocyte apoptosis in oral lichen planus by targeting MMP-2 expression through PI3K/Akt/mTOR pathway

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease that involves the degeneration of keratinocytes. However, the etiology and mechanisms of OLP pathogenesis have not been fully elucidated. In this study, we used keratinocytes HaCaT stimulated with lipopolysaccharide (LPS) to mimic a local OLP immune environment, and investigated the regulatory role of miR-125b in keratinocyte proliferation and apoptosis under OLP conditions. Immunohistochemical analysis and quantitative real-time PCR (qRT-PCR) assay showed that MMP-2 expression was up-regulated and miR-125b expression was down-regulated in both OLP mucosa tissues and LPS-incubated HaCaT cells. Western blot analysis indicated that miR-125b overexpression suppressed LPS-induced MMP-2 expression in HaCaT cells. Molecularly, our results confirmed that MMP-2 is a target gene of miR-125b in HaCaT cells. The effect of miR-125b on cell proliferation was revealed by CCK-8 assay, BrdU assay and cell cycle analysis, which illustrated that miR-125b overexpression impeded LPS-induced HaCaT cell proliferation. Flow cytometry analysis further demonstrated that miR-125b overexpression promoted HaCaT cell apoptosis. Moreover, these effects were involved in PI3K/Akt/mTOR activation, as miR-125b overexpression inhibited LPS-enhanced expression of p-Akt and p-mTOR proteins. Taken together, these data confirm that miR-125b might inhibit keratinocyte proliferation and promote keratinocyte apoptosis in OLP pathogenesis by targeting MMP-2 through PI3K/Akt/mTOR pathway.

Sera and salivary matrix metalloproteinases are elevated in patients with vesiculoerosive disease: a pilot study

BACKGROUND

Oral vesiculoerosive (VE) diseases, such as lichen planus and mucous membrane pemphigoid, are immune-mediated pathoses. Matrix metalloproteinase (MMP)-2 and MMP-9 are elevated in oral lesional biopsy specimens of patients with VE disease. However, the systemic levels and activity of MMP-2 and MMP-9 in this patient population are poorly understood. We performed a pilot study to determine whether the levels and activity of MMP-2 and MMP-9 are elevated in the sera and saliva of patients with VE disease.

STUDY DESIGN

We recruited patients with VE disease (n = 10) and healthy controls (n = 19). We collected sera and saliva and performed enzyme-linked immunosorbent assays to measure MMP levels. We used gelatin zymography and Biotrak assays to determine enzyme activity. Data were analyzed using the Mann-Whitney test.

RESULTS

There was no difference in the activity of either MMP in the sera or saliva of patients with VE disease compared with controls. Significantly, MMP-2 levels were elevated in the sera of patients with VE disease (P < .0001), whereas MMP-9 was elevated in their saliva (P = .003).

CONCLUSIONS

MMP-2 is elevated in the sera of patients with VE disease, and MMP-9 is increased in their saliva. Therefore, these enzymes may be potential markers of disease or therapeutic targets.

Comparison of Low-Level Laser Therapy versus Ozone Therapy in the Treatment of Oral Lichen Planus

BACKGROUND

The treatment options for oral lichen planus (OLP) are numerous and include topical and systemic agents. Intralesional and systemic corticosteroids are used; however, the therapeutic results are often disappointing.

OBJECTIVE

To compare the influence of ozone, laser, and topical corticosteroid therapies in the treatment of OLP.

METHODS

One hundred twenty adult patients with ≤3 cm atrophic-erosive biopsy-proven OLPs in the tongue or buccal mucosa were recruited into the study. They were randomly assigned, by preoperative envelope drawing, to be treated with low-level laser therapy (LLLT group), ozone therapy (ozonated group), and topical corticosteroid therapy (positive control group). A placebo treatment containing base ointment without the active corticosteroid component was administered to patients in the negative control group. Response rate scores were determined on the basis of changes in the appearance score and pain score of the lesions between baseline and after each treatment.

RESULTS

The study subjects consisted of 56 male and 64 female OLP patients with a combined mean age of 42.6±8.3 years (range, 28~55 years). No statistically significant difference was detected in clinical severity among the groups. The sign scores decreased in almost all scoring groups; however, statistically significant improvement was found in the ozonated and corticosteroid-treated groups. Symptom improvement was achieved after treatment with LLLT, ozone, and corticosteroid (p<0.05). The efficacy indices were significantly higher in the ozonated and corticosteroid-treated groups.

CONCLUSION

Ozone and corticosteroid therapies were more effective than 808-nm LLLT in the treatment of OLP.

Inhibition of invasion and metastasis of human liver cancer HCCLM3 cells by portulacerebroside A

CONTEXT

Portulacerebroside A (PCA) is a novel cerebroside compound isolated from Portulaca oleracea L. (Portulacaceae), an edible and medicinal plant distributed in the temperate and tropical zones worldwide.

OBJECTIVE

This study investigates the effects of PCA in human liver cancer HCCLM3 cells on metastasis and invasion.

MATERIALS AND METHODS

After the cells were treated with PCA (2.5, 5, and 10 μg/ml) for 6, 12, 24, or 48 h, adhesion, transwell invasion, and scratch tests were conducted and cell functions were evaluated. Western blot and FQ-RT-PCR assays explored the mechanism of PCA-inhibited invasion and metastasis in the cells.

RESULTS

The adhesion rate of the cells was suppressed at 0.5 h (79.4 ± 1.0, 68.7 ± 1.3, and 58.1 ± 1.3%, versus 100 ± 1.5% in the control), 1 h (78.2 ± 1.2, 70.9 ± 1.6, and 55.4 ± 1.9%, versus 100 ± 1.2% in the control), and 1.5 h (71.6 ± 1.1, 62.3 ± 0.9, and 50.4 ± 0.9%, versus 100 ± 1.1% in the control). The 24 h invasion ability was decreased (356.6 ± 11.2, 204.0 ± 17.6, and 113.0 ± 9.5%, versus 443.6 ± 15.4% in the control). The migration capability was also restrained by PCA for 24 h (324.8 ± 25.4, 250.4 ± 21.0, and 126.3 ± 10.1, versus 381.6 ± 30.6 in the control) and 48 h (470.3 ± 34.3, 404.0 ± 19.7, and 201.0 ± 15.4, versus 752.0 ± 63.6 in the control). There was an increase in the mRNA and protein expression levels of TIMP-2 and nm23-H1, inhibition in the mRNA expression of MTA1, MMP-2, and MMP-9, and suppression in the protein expression of MTA1, RhoA, Rac1/Cdc42, MMP-2, but not RhoC and MMP-9.

CONCLUSION

PCA suppresses the invasion and metastasis of HCCLM3 cells possibly by modulation of the mRNA and protein expression of related parameters. This is the first study to reveal a new potential therapeutic application of PCA in antimetastatic therapy for liver cancer.

Baicalein reduces the invasion of glioma cells via reducing the activity of p38 signaling pathway

Baicalein, one of the major flavonids in Scutellaria baicalensis, has historically been used in anti-inflammatory and anti-cancer therapies. However, the anti-metastatic effect and related mechanism(s) in glioma are still unclear. In this study, we thus utilized glioma cell lines U87MG and U251MG to explore the effect of baicalein. We found that administration of baicalein significantly inhibited migration and invasion of glioma cells. In addition, after treating with baicalein for 24 h, there was a decrease in the levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 expression as well as proteinase activity in glioma cells. Conversely, the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 was increased in a dose-dependent manner. Moreover, baicalein treatment significantly decreased the phosphorylated level of p38, but not ERK1/2, JNK1/2 and PI3K/Akt. Combined treatment with a p38 inhibitor (SB203580) and baicalein resulted in the synergistic reduction of MMP-2 and MMP-9 expression and then increase of TIMP-1 and TIMP-2 expression; and the invasive capabilities of U87MG cells were also inhibited. However, p38 chemical activator (anisomycin) could block these effects produced by baicalein, suggesting baicalein directly downregulate the p38 signaling pathway. In conclusion, baicalein inhibits glioma cells invasion and metastasis by reducing cell motility and migration via suppression of p38 signaling pathway, suggesting that baicalein is a potential therapeutic agent for glioma.

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.