Expressions of tumor necrosis factor-α, caspase-8 and caspase-3 in lichen planus lesions

Abstract

Objective To quantify the expressions of tumor necrosis factor-α (TNF-α),caspase-8 and caspase-3 in lichen planus (LP) lesions,and to investigate their significance.Methods Skin samples were collected from the lesions of 20 patients with LP and normal skin of 20 healthy human controls.Immunohistochemistry was used to determine the expressions of TNF-αt,caspase-8 and caspase-3,and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) technique to evaluate the apoptosis in keratinocytes,in these samples.Results The expression levels (expressed in integrated optical density,IOD)of TNF-α,caspase-8 and caspase-3 were (12.58 ± 2.33) × 103,(11.69 ± 3.52) × 103 and (11.45 ± 2.82) × 103 respectively in LP lesions,significantly higher than those in the normal skin ((5.12 ± 1.78) × 103,(3.87 ± 3.36)× 103,(4.76 ± 1.93) × 103,t =11.38,7.19,8.76,respectively,all P ＜ 0.01).Elevated apoptosis index was noted in keratinocytes from LP lesions compared with those from normal skin (71.35 ± 7.93 vs.33.62 ± 8.75,t =14.29,P ＜ 0.01).In LP lesions,the expressions of both TNF-α and caspase-8 were positively correlated with the apoptosis index of keratinocytes (r =0.72,0.75,respectively,both P ＜ 0.01) and the expression of caspase-3 (r =0.68,0.73,respectively,both P ＜ 0.01).Conclusion The up-regulated expressions of TNF-α,caspase-8 and caspase-3 may participate in the apoptosis in keratinocytes in LP. Key words: Lichen planus; Tumor necrosis factor-alpha; Caspase 8; Caspase 3; Apoptosis