白癜风患者表皮角质形成细胞凋亡及其与表皮片移植疗效的关系

目的 探讨稳定期白癜风患者皮肤角质形成细胞(KC)的凋亡与表皮片移植疗效的相关性.方法 取44例稳定期白癜风患者的正常腹部皮肤和白斑区皮肤,采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记技术(TUNEL)检测KC的凋亡状况,同时采用免疫组化法检测28例稳定期白癜风患者KC凋亡相关蛋白Caspase 3、8、9及bcl-2、P53的表达情况.结果 TUNEL结果显示,皮损区阳性细胞数与供皮区皮肤相比差异有统计学意义.免疫组化结果:阳性反应定位于KC的胞膜与胞质,阳性细胞主要分布于表皮的中下层.白斑区Caspase 3有19例表达为阳性,而供皮区皮肤为9例.白斑区Caspase 8和9的阳性表达分别为15和16例,供皮区皮肤分别为5和4例.P53在两组标本中的表达都为阴性;Bcl-2在皮损区为阴性,供皮区皮肤中表达为弱阳性.表皮片移植失败组供皮区皮肤中凋亡的KC数目(15.83±2.69)明显多于移植成功组供皮区皮肤(9.24±1.80).结论 白癜风患者皮损区KC凋亡比供皮区皮肤明显,凋亡相关蛋白Caspase 3、8、9表达升高.KC凋亡可能与移植疗效存在一定的相关性.

Relationship of apoptosis in epidermal keratinocytes with efficacy of epidermal grafting in patients with vitiligo

Objective To investigate the relationship between apoptosis in epidermal keratinocytes and efficacy of epidermal grafting. Methods Epidermal specimens were obtained from donor sites and depigmented area of 44 patients with vitiligo receiving epidermal grafting. The apoptosis in keratinocytes was determined by terminal deoxynucleotidyl transferase end-labeling (TUNEL) assay, and the expressions of caspase 3, 8, 9 as well as bcl-2 and P53 were evaluated by immunohistochemistry. Results As TUNEL assay showed, the number of apoptotic keratinocytes in epidermis from depigmented area differed significantly from that from donor sites.The expressions of caspase 3, 8 and 9 were mainly located in the membrane and cytoplasm of keratinocytes,and positive keratinocytes were predominately distributed in the middle and lower layer of the epidermis. Of the 44 patients, 19, 15 and 16 were positive for the expressions of caspase 3, 8 and 9 in the depigmented epidermis,respectively, and 9, 5 and 4 for those in the donor epidermis, respectively. P53 was expressed in neither donor epidermis nor depigmented epidermis, while Bcl-2 was weakly positive in donor epidermis and negative in depigmented epidermis. The number of apoptotic keratinocytes was higher in donor epidermis from patients failing to respond to the transplantation than in that from patients successfully treated by transplantation (15.83 ± 2.69 vs.9.24 ± 1.80, t = 10.96, P < 0.01 ). Conclusions There is an obvious apoptosis in keratinocytes from depigmented epidermis of patients with vitiligo, together with an increase in the expression of caspase 3, 8 and 9. The apoptosis in keratinocytes may be related to the efficacy of epidermal transplantation.