目的:研究倍他米松(betamethasone,BT)对毛囊无色素黑素细胞(amelanotic melanocytes,AMMC)的激活作用。方法:以高、中、低3种不同浓度的BT作用于培养的人毛囊外毛根鞘AMMC,测定药物作用前后酪氨酸酶(tyrosinase,TYR)活性和黑素生成的变化。通过间接免疫荧光法结合激光共聚焦显微镜半定量分析药物作用前、后AMMC TYR、酪氨酸酶相关蛋白(ty-rosinase related protein,TRP)-1和TRP-2表达的变化,透射电镜分析黑素小体在药物作用前后的变化。结果:BT促进了AMMC表达TYR和TRP-1,并且以剂量依赖方式促进TYR活性,诱导黑素生成。AMMC主要含有Ⅰ、Ⅱ和Ⅲ期黑素小体,但是BT作用后AMMC含有大量Ⅲ或Ⅳ期黑素小体,并且以Ⅳ期黑素小体为主。结论:BT能够激活AMMC,这可能部分解释了糖皮质激素治疗白癜风的机制。
目的进一步改良人毛囊无色素黑素细胞(amelanotic melanocytes,AMMC)培养的方法,并研究了AMMC内黑素生成相关酶的表达:酪氨酸酶(tyrosinase,TYR)、酪氨酸酶相关蛋白-1(tyrosinase related protein-1,TRP-1)和酪氨酸酶相关蛋白-2(tyrosinase related protein-1,TRP-2)。方法采用1%分离酶(dispase)消化分离毛囊,选用含干细胞因子(stem cell factor,SCF)、内皮素-3(endothelin-3,ET-3)、碱性成纤维细胞生长因子(basicfibroblast grow factor,bFGF)和霍乱毒素(cholera toxin,CT)的成黑素细胞培养基培养AMMC,同时培养表皮黑素细胞(melanocytes,MC)作为对照,采用免疫组化、多巴染色和透射电镜对细胞进行鉴定,蛋白印记法分析TYR、TRP-1和TRP-2的表达。结果1%分离酶消化24h可以容易获得游离的毛囊,结合我们所用的培养基完全排除了成纤维细胞的污染。所用成黑素细胞培养基促AMMC增殖明显,细胞可传5代以上。免疫组化结果显示,AMMC表达gp100、酪氨酸酶(tyrosinase,TYR)、酪氨酸酶相关蛋白-1(tyrosinase related protein-1,TRP-1)和酪氨酸酶相关蛋白-2(tyrosinase related protein-1,TRP-2),证明培养的细胞为黑素细胞。AMMC的多巴染色呈阴性,并且透射电镜发现AMMC胞质中仅含大量的I期、II期黑素小体,未见III、IV期黑素小体,因此说明AMMC处于未分化状态。TYR和TRP-1在MC中的表达明显强于AMMC,TRP-2的表达在两种细胞间没有明显差别,进一步说明AMMC与MC具有异质性。结论我们成功培养了完全纯化、快速增殖的AMMC,并且培养的细胞不能生成黑素,生物学性状更接近活体中的状态,其与表皮黑素细胞具有异质性。
To investigate the ultra structure of amelanotic melanocytes （AMMC）. Methods： The hair follicles obtained from normal human scalp by 0.50% collagenase type V treatment were washed with 0.1 mol/L phosphate buffer salt （PBS）. Hair-follicle cell suspensions were prepared by trypsin treatment and cultured in melanocyte medium. Remaining keratinocytes were removed by differential trypsinization. 100μg/ml geneticin was used to eliminate the contaminating fibroblasts. At third passage, the cells were trypsinized, and then washed in phosphate-buffered saline and processed for transmission electron microscopy. Results： Under transmission electron microscope, the cultured cells showed round or oval shape, with single large nuclear and the karyotheca were double deck. There were obvious euchromosome within the nucleus, and sparse heterochromosome. There were various organelles in the cytoplasm, including plentiful melanosomes with nearly similar size, mitochondria, rough endoplasmic reticule （RER） and ribosome. The electron density granules in most of the melanosomes disposed along concentric circularities. Golgi apparatus in the cells was inconspicuous. Conclusion： The ultra structure of AMMC from human hair follicles is different from that of epidermal melanocytes, and these characteristics determine the functional immature of AMMC.
Ruzhi ZhangWenyuan ZhuMingyu XiaDaguang WangHuijun Ma
