小眼畸形相关转录因子转录调控与白癜风临床类型的相关性研究

Correlation Between Microphthalmia-associated Transcription Factor and Clinical Pattern in Vitiligo Patients

目的研究小眼畸形相关转录因子(MITF)及其转录调控的酪氨酸酶相关蛋白(TRPs)与白癜风临床类型的相关性。方法选择非节段型白癜风(NSV)17例和节段型白癜风(SV)13例,对所有病例均取白斑区、远离白斑正常肤色区的表皮片,首先应用免疫组织化学方法原位检测黑素细胞的MITF及其主要转录调控分子酪氨酸酶(TYR)、酪氨酸酶相关蛋白1(TYRP1)和酪氨酸酶相关蛋白2(TYRP2)的表达情况,并对所有30例远离白斑正常肤色区的表皮黑素细胞进行培养,应用免疫印迹方法检测培养的黑素细胞MITF及TYR、TYRP1和TYRP2的表达情况。结果 (1)原位表达结果:白斑区:所有病例MITF及TYR、TYRP1和TYRP2的表达均为阴性;正常肤色区:SV的MITF表达显著抑制,与NSV及正常人对比均具有统计学差异(P<0.05),NSV的MITF、NSV与SV的TYR、TYRP1和TYRP2表达与正常人对比均没有统计学差异(P>0.05)。(2)培养黑素细胞的蛋白表达结果:NSV的TYRP2表达下调,与正常人对比具有统计学差异(P<0.05),而MITF、TYR和TYRP1表达正常;SV的MITF与NSV及正常人对比均具有统计学差异(P<0.05),而TYR、TYRP1和TYRP2正常表达。结论 NSV和SV可能存在不同的MITF转录调控机制。

Objective To analyze the expression of microphthalmia - associated transcription factor （MITF） , tyrosinase - related proteins（TRPs） and the correlation with clinical pattern in patients with vitiligo. Methods Suction epidermal sheets were taken from le- sional and non - lesional skin from patients of 17 non - segmental vitiligo （NSV） and 13 segmental vitiligo （SV） respectively. MITF and its transcriptional molecules tyrosinase （TYR）, tyrosinase -related protein -1 （TYRP1） , and tyrosinase -related protein -2 （TYRP2） of melanocytes from lesional and non - lesional skin were detected by immunohistochemistry. MITF, TYR, TYRP1 and TYRP2 of cultured melanocytes from non -lesional vitiligo skin were detected by Western Blotting. Results The expression of MITF, TYR, TYRP1 and TYRP2 in situ：the expression of MITF, TYR, TYRP1 and TYRP2 from depigmented lesions was all negative. In normal area of vitiligo patients, the expression of TYR, TYRP1 and TYRP2 was normal both in NSV and SV;but the expression of MITF in SV patients de- creased dramatically compared with NSV and healthy people （ P 〈 0.05 ）. MITF in NSV patients was no statistically difference from healthy people （P 〉 O. 05）. Proteins expression of MITF, TYR, TYRP1 and TYRP2 in cultured melanocytes： in NSV patients,the expression of MITF, TYR and TYRP1 had all no statistically difference from SV and healthy people（P 〉 0.05）. But TYRP2 had statistically difference from healthy people （P 〈 O. 05）. Comparatively, in SV patients, the expression of MITF protein showed statistically difference from NSV and healthy people （P 〈 0.05） ,but the expression of TYR, TYRP1 and TYRP2 were almost normal. Conclusion There may exist differ- ent pathogenesis about the transcriptional role of MITF between NSV and SV.