Apoptosis in oral lichen planus

Abstract

Apoptotic cell death may be a contributory cause of basal cell destruction in oral lichen planus (OLP). Therefore. the purpose of this study was to investigate the rate of apoptosis in OLP and the expression of two proteins (FasR and FasL) regulating this process. Biopsies from 18 patients with histologically diagnosed OLP were investigated, with comparison to normal oral mucosa of healthy persons. For visualisation of DNA fragmentation, the TUNEL method was used. In order to characterise the infiltrating cell population (CD3. CD4, CD8) and expression of FasR and FasL, we used an immunohistochemical technique. The results showed that T cells dominated in the subepithelial cell infiltrate. Within the epithelium the apoptotic cells were confined to the basal cell layer, and more apoptotic cells were seen in areas with basal cell degeneration and atrophic epithelium. There was a prominent expression of FasR/FasL in OLP. with a rather uniform distribution throughout the inflammatory cell infiltrate. In the epithelium, the FasR/FasL expression was more abundant in the basal cell area compared to the suprabasal cell layer. In conclusion, apoptosis within the epithelium is significantly increased in situ in OLP compared to normal oral mucosa, and seems to be related to the epithelial thickness.

Possible Role of TNF-α, IFN-γ, FAS/APO1 in the Etiopathogenesis of Lichen Planus

“…They demonstrated that the expression of Fas R/Fas L was prominent in OLP. In the epithelium, the Fas R/Fas L expression was more abundant in the basal cell area compared to the suprabasal cell layer [13]. Shen et al studied the expression of Fas/Fas L in 50 OLP and 10 control group with immunohistochemical TUNEL method, and determined Fas expression to be ≥ 50 % in 34/50 cases.…”

“…Recently, it has been shown that perforin (pore forming protein) and granzymes, which are the major components of cytoplasmic granules of CTLs and NK cells, are influential in CTL-and NK-cell mediated apoptosis. The Fas system is involved in activation-induced suicide of T cells and downregulation of immune reaction [13].…”

Estudo comparativo das alterações celulares no líquen plano e no carcinoma epidermóide bucal

“…Finally, it should be noted that although recent studies have proposed using more advanced methods for studying the potential for malignant transformation of OLP, [16][17][18][19] more detailed knowledge of its histopathological features, and especially of its clinical progression, remain essential to understand the true nature of this disease.…”

Eradication of damaged keratinocytes in cutaneous lichen planus forms demonstrated by evaluation of epidermal and follicular expression of CK15, indices of apoptosis and regulatory protein S100

“…The apoptotic process mediated by CD8 positive cytotoxic T lymphocytes and natural killers follows either the perforin/granzyme pathway or Fas/Fas ligand pathway, when cytotoxic proteins are launched to perform disseminated keratinocyte death [28,29,30,31,32,33,34]. However, cell death may also be induced by other mechanisms than those initiated by T cells, such as loss of cell-to-cell or cell-to-matrix contacts [34,35].…”