扁平苔藓皮损中Caspase-9和Apaf-1的表达及其与细胞凋亡的关系

目的 探讨扁平苔藓皮损中Caspase-9、Apaf-1的表达及其与细胞凋亡的关系。方法 采用DNA末端转移酶介导的原位缺口末端标记法（TUNEL法）和免疫组化的方法检测30例扁平苔藓皮损和30例正常人皮肤组织中细胞凋亡和Caspase-9、Apaf-1的表达情况，采用RT-PCR检测10例扁平苔藓皮损和8例正常人皮肤组织中Caspase-9 mRNA的表达情况。结果 扁平苔藓组表皮层角质形成细胞的凋亡指数（AI）为75.67 ± 9.4，正常人对照组为38.15 ± 9.6，两组比较，差异有统计学意义（P ＜ 0.05）；Caspase-9和Apaf-1表达的阳性单位分别为14.45 ± 2.72和11.93 ± 3.14，明显高于正常人对照组（P ＜ 0.01）；而且Caspase-9 mRNA的表达量（2.304 ± 0.417）与正常人对照组（1.605 ± 0.381）比较，差异有统计学意义（P ＜ 0.01）。扁平苔藓皮损中Caspase-9、Apaf-1阳性表达强度均与其自身角质形成细胞的AI呈正相关（r = 0.96和0.94，P ＜ 0.01）。结论 扁平苔藓皮损中角质形成细胞凋亡亢进可能与扁平苔藓的发生有关，Caspase-9、Apaf-1与角质形成细胞的凋亡关系密切。

Expressions of caspase-9 and Apaf-1 in lichen planus and their relationship with the apoptosis of keratinocytes

Objective To investigate the expressions of caspase-9 and Apaf-1 and their relationship with the apoptosis of keratinocytes in lichen planus （LP）. Methods Biopsy samples were resected from 30 patients with LP and 30 normal human controls. Terminal deoxynucleotidyl transferase （TdT）-mediated dUTP nick-end labeling （TUNEL） was used to examine the apoptosis of keratinocytes, immunohistochemistry to study the expressions of caspase-9 and Apaf-1 in samples. The mRNA expression of caspase-9 was detected with RT-PCR in 10 samples from patients with LP and 8 from normal controls. Results The apoptosis index of keratinocytes and mRNA expression of caspase-9 were higher in lichen planus than those in normal controls （75.67 ± 9.4 vs 38.15 ± 9.6, 2.30 ± 0.42 vs 1.60 ± 0.38, respectively, P < 0.05）. The positive units of caspase-9 and Apaf-1 were 14.45 ± 2.72 and 11.93 ± 3.14, respectively, in lichen planus, both of which were up-regulated compared with those in the normal controls （both P < 0.01）. Both the expressions of caspase-9 and Apaf-1 were positively correlated with the corresponding apoptosis index of keratinocytes （r1 = 0.96, 0.94, respectively, both P < 0.01）. Conclusions The accelerated apoptosis of keratinocytes is associated with the expressions of caspase-9 and Apaf-1, and may contribute to the formation and progress of lichen planus.