Sun Lijun, Sun Jingying, Huo Xueping, Li Yaping, Li Yuan, Xie Xin, Hu Jun
Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China.
Ministry-of-Education Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Science, Northwest University, Xi'an 710069, China. *Corresponding author, E-mail:
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2016 Nov;32(11):1466-1470.
Objective To explore the effect of Toll-like receptor 4 (TLR4) activation on melanogenesis in melanocytes. Methods The primary melanocytes were isolated, cultured and then stimulated by TLR4 agonist lipopolysaccharide (LPS). Firstly, the melanin content changes were detected in melanocytes, and then quantitative real-time PCR and Western blotting were employed to determine the expression levels of pre-melanosomal protein (Pmel17), tyrosinase (TYR) and microphthalmia-associated transcription factor (MITF). Finally, the melanosomes were observed by electron microscopy. Results After stimulated by LPS, melanin formation in melanocytes was significantly reduced. The expressions of Pmel17 and TYR were markedly suppressed, which depended on the regulation of transcription factor MITF. The electron microscopy showed that melanosome synthesis was inhibited. Conclusion TLR4 activation reduces melanin synthesis in melanocytes, which indicates that the bacterial products may affect melanin synthesis through innate immunity.
目的 探讨Toll样受体4（TLR4）激活对黑素细胞黑素生成的影响。方法 分离、培养原代黑素细胞，然后用TLR4激动剂脂多糖（LPS）刺激。首先，检测黑素细胞中黑色素含量的变化，然后采用定量实时聚合酶链反应和蛋白质免疫印迹法测定前黑素小体蛋白（Pmel17）、酪氨酸酶（TYR）和小眼相关转录因子（MITF）的表达水平。最后，通过电子显微镜观察黑素小体。结果 LPS刺激后，黑素细胞中黑色素的形成明显减少。Pmel17和TYR的表达明显受到抑制，这依赖于转录因子MITF的调控。电子显微镜显示黑素小体的合成受到抑制。结论 TLR4激活可减少黑素细胞中黑色素的合成，这表明细菌产物可能通过固有免疫影响黑色素的合成。
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