小鼠毛囊不同生长周期中MITF下游色素相关基因的定位表达及相关性分析

Localization and Correlation Analysis of MITF Downstream Pigmentation-related Genes at Different Growth Cycle of Mouse Hair Follicle

小眼畸形转录因子(MITF)不仅是黑色素细胞发育、增殖和存活的必要调节因子,而且对调节相关酶和黑素体蛋白表达来确保黑色素产生具有至关重要的作用。MITF下游色素相关基因在小鼠毛囊生长周期中的表达及相关性仍有待研究。HE染色结果表明不同毛囊时期的小鼠毛囊呈现典型的组织形态学结构;免疫组织化学显示,MITF、GPNMB、OA1、TYR、TYRP2在不同毛囊生长周期中的毛基质及内外毛根鞘均有不同程度的阳性表达。黑色素测定结果表明,在毛囊生长初期和中期,碱性可溶性总黑色素(ASM)、真黑素(EM)以及褐黑素(PM)相对含量高于毛囊生长末期。蛋白免疫印迹结果表明,MITF、GPNMB、OA1、TYR、TYRP2在毛囊生长初期和中期蛋白质相对水平明显高于毛囊生长末期。实时荧光定量PCR结果表明,MITF、GPNMB、OA1、TYR、TYRP2、PMEL在毛囊生长初期和中期,mRNA相对表达量显著高于毛囊生长末期。在不同毛囊生长周期小鼠皮肤的MITF下游色素相关基因表达存在显著差异,表明上述因子在维持黑色素细胞色素生成是不可或缺的因素。

Microphthalmia-associated transcription factor （MITF） is an essential regulator not only for melanocyte development, proliferation and survival, but also for the expression of regulation of related enzymes and melanosomal proteins ensuring the production of melanin. Expression and correlation of MITF downstream pigmentation-related genes at growth cycle of mouse hair follicle remains unclear. The results of HE staining showed typical histological characteristics of hair follicles at different stages of the hair growth cycle. Immunohistochemistry analysis showed that MITF, GPNMB, OA1, TYR and TYRP2 were positively expressed in the matrix, outer root sheath, and inner root sheath of hair follicles at different stages of hair growth cycle. The results of melanin assay showed that the relative levels of alkali- soluble melanins （ASM） , eumelanin （EM） and pheomelanin （PM） in anagen and catagen were higher than that of telogen. The results of Western blot analysis showed that the relative levels of MITF, GPNMB, OA1, TYR and TYRP2 in anagen and catagen were significantly higher than that of telogen. The results of real-time quantitative PCR showed that the relative mRNA levels of MITF, GPNMB, OA1, TYR, TYRP2 and PMEL in anagen and catagen were significantly higher than that of telogen. There were significant differences in MITF downstream pigmentation-related genes, expression in skin of different phases of the hair follicle growth cycle, indicating that the above genes are involved in melanogenesis.