title: [Toll-like receptor 4 activation inhibits melanogenesis in melanocytes].
abstract: 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.
authors: Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China.
authors: Lijun
authors: L
authors: Sun
authors: Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China.
authors: Jingying
authors: J
authors: Sun
authors: Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China.
authors: Xueping
authors: X
authors: Huo
authors: Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China.
authors: Yaping
authors: Y
authors: Li
authors: Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China.
authors: Yuan
authors: Y
authors: Li
authors: 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: xiexin@nwu.edu.cn.
authors: Xin
authors: X
authors: Xie
authors: Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China. *Corresponding authors, E-mail: 45745642@qq.com.
authors: Jun
authors: J
authors: Hu
mesh_terms: D002478:Cells, Cultured; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008543:Melanins / Q000378:metabolism*; D008544:Melanocytes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D020460:Melanosomes / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D051739:Microphthalmia-Associated Transcription Factor / Q000378:metabolism; D008854:Microscopy, Electron; D014442:Monophenol Monooxygenase / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D058951:gp100 Melanoma Antigen
chemical_list: D008070:Lipopolysaccharides; D008543:Melanins; D051739:Microphthalmia-Associated Transcription Factor; C548637:PMEL protein, human; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D058951:gp100 Melanoma Antigen; D014442:Monophenol Monooxygenase