人类角质形成细胞中调节细胞内信号传导的Toll样受体(TLR2)对糠秕马拉色菌的反应

Toll-like receptors (TLRs) are crucial players in the innate immune response to microbial invaders. The lipophilic yeast Malassezia furfur has been implicated in the triggering of scalp lesions in psoriasis. The aim of the present study was to assess the role of TLRs in the defence against M. furfur infection. The expression of the myeloid differentiation factor 88 (MyD88) gene, which is involved in the signalling pathway of many TLRs, was also analysed. In addition, a possible correlation of antimicrobial peptides of the β -defensin family to TLRs was tested. Human keratinocytes infected with M. furfur and a variety oiM. furfur-positive psoriatic skin biopsies were analysed by RT-PCR, for TLRs, MyD88, human β -defensin 2 (HBD- 2), HBD- 3 and interleukin- 8 (IL- 8) mRNA expression. When keratinocytes were infected with M. furfur, an up-regulation for TLR2, MyD88, HBD- 2, HBD- 3 and IL- 8 mRNA was demonstrated, compared to the untreated cells. The same results were obtained when psoriatic skin biopsies were analysed. The M. furfur-induced increase in HBD- 2 and IL- 8 gene expression is inhibited by anti-TLR2 neutralising antibodies, suggesting that TLR2 is involved in the M. furfur-induced expression of these molecules. These findings suggest the importance of TLRs in skin protection against fungi and the importance of keratinocytes as a component of innate immunity.

靛玉红对角质形成细胞中促炎细胞因子表达水平的影响

目的:探讨靛玉红对人类永生化角质形成细胞株(HaCaT细胞)中促炎细胞因子IL-1β、IL-6、TNF-α表达水平的影响,初步阐明青黛膏治疗银屑病的机制。方法:以人类永生化角质形成细胞株HaCaT细胞作为研究对象,观察不同浓度靛玉红处理后HaCaT细胞中促炎细胞因子IL-1β、IL-6、TNF-α表达水平的变化,采用ELISA检测各组细胞培养上清液中IL-1β、IL-6、TNF-α的分泌水平,RT-qPCR检测各组细胞中IL-1β、IL-6、TNF-α的mRNA表达水平。结果:靛玉红处理后,HaCaT细胞中促炎细胞因子IL-1β、IL-6、TNF-αmRNA表达水平及细胞培养上清液中三者分泌水平均明显降低,差异均具有统计学意义(P值<0.05)。随着靛玉红浓度升高,该抑制作用增强,呈一定的浓度依赖性。结论:青黛膏的主要成分靛玉红可能通过降低HaCaT细胞中IL-1β、IL-6、TNF-α等银屑病相关炎性因子的表达水平从而发挥治疗银屑病的作用。

HaCaT细胞内沙眼衣原体对大环内酯类抗生素敏感性检测

目的:检测体外HaCaT细胞内沙眼衣原体对大环内酯类抗生素的敏感性。方法:微量稀释法检测沙眼衣原体E型标准株和34例临床株在HaCaT细胞和McCoy细胞中对红霉素、克拉霉素及阿奇霉素在体外的敏感性。同一抗生素在两种细胞的最低抑菌浓度(MIC)值进行配对t检验。结果:沙眼衣原体E型标准株在两种细胞内对红霉素、克拉霉素及阿奇霉素的MIC值一致。在HaCaT细胞和McCoy细胞中测得临床株的MIC最大值,比以往报道的MIC值均有所升高。在两种细胞中红霉素、克拉霉素及阿奇霉素对临床株的MIC值经配对t检验差异有统计学意义,且在HaCaI细胞中MIC值高于McCoy细胞中的MIC值。结论:体外沙眼衣原体对大环内酯类抗生素的敏感性在不同培养细胞HaCaT细胞和McCoy细胞间存在差异。

使用体外重建皮肤模型研究真皮成纤维细胞对皮肤色素沉着的重要调节作用：皮肤光老化的影响

已有大量研究强调了人类角质形成细胞在皮肤色素沉着中所起的作用。例如，角质形成细胞通过释放大量的促色素沉着旁分泌生长因子，如αMSH、内皮素1（ET-1）、干细胞因子（SCF）和多种细胞因子，参与紫外线（UV）急性照射诱导的黑素合成（晒黑）。然而，越来越多的证据显示，真皮内成分在皮肤色素沉着调控中的作用不容忽视。20世纪90年代中期，证实细胞外基质（ECM）可调节黑素细胞的增殖、凋亡抑制和黑素生成活性。有报道证实，真皮成纤维细胞可通过分泌可溶性因子对色素沉着起调控作用。另外，对于构成性肤色，研究发现在掌跖，由成纤维细胞产生的Dikkopf-1（DKK-1）对黑素细胞的生长、活性以及对黑素小体转移均有抑制作用，且认为是这两处身体部位颜色较浅的原因。反之，深肤色皮肤内成纤维细胞分泌的神经调节蛋白1（NGR-1）的促色素沉着效应提示，该特定信号分子在决定高度色素沉着的皮肤类型中发挥作用。此外，在各种先天性色素沉着过度障碍中，如系统性硬皮病、皮肤纤维瘤、多发性神经纤维瘤的咖啡牛奶斑和泛发性进行性色素异常症，已知真皮黑素生成生长因子数量增加；这些因子包括SCF、肝细胞生长因子（HGF）或角质形成细胞生长因子（KGF）。表皮与细胞间质之间紧密的互动也可能在黑素细胞内稳态中发挥作用。最近已证实，层粘连蛋白332可通过调节L酪氨酸摄取来促进黑素生成。生长因子/细胞因子调节环也存在于真皮细胞和表皮细胞之间，并参与色素沉着的调控。