马拉色菌对角质形成细胞分泌黑素合成相关细胞因子的影响

目的探讨引起花斑癣不同临床色素表现的马拉色菌与角质形成细胞共培养,导致与黑素合成相关的细胞因子的变化。方法MTT法筛选不同比例的马拉色菌对角质形成细胞增殖率的影响;用色沉和色减区分离的马拉色菌与角质形成细胞共培养,在不同时间段收集上清液,ELISA法测定碱性成纤维细胞因子（b-FGF）、内皮素-1（ET-1）、神经生长因子-β（NGF-β）、白介素-1α（IL-1α）、白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）和干细胞因子（SCF）的动态变化。结果角质形成细胞与马拉色菌在1∶10比例以下,角质形成细胞的生长状况不受马拉色菌的影响（P〉0.05）。当比例提高至1∶20以上时,角质形成细胞的生长受到显著抑制（P〈0.01）。马拉色菌刺激角质形成细胞分泌IL-1α、IL-6、TNF-α、ET-1增加（P〈0.01）。未检测到b-FGF、NGF-β和SCF的产生（P〉0.05）。色沉区马拉色菌刺激产生的ET-1显著高于色减区（P〈0.01）。结论马拉色菌刺激角质形成细胞分泌黑素合成相关因子的能力不同。ET-1在花斑癣色素沉着中可能起了一定作用。

Effects of Malassezia isolates on cytokines production associated with melanogenesis by keratinocytes

OBJECTIVE: To investigate the co-culture of keratinocytes with Malassezia isolates which cause the pityriasis versicolor with different color and to analyze the changes of cytokines associated with melanogenesis. METHODS: The effects of Malassezia species with different proportions on the growth rate of keratinocytes was assessed with 5 g/L methyl thiazolyl tetrazolium (MTT). Co-culture of keratinocytes and Malassezia species were performed with isolates from hyer- and hypo-pigmentation areas of pityriasis versicolor. The supernatants were collected at different time points, and the changes of basic fibroblast growth factor (b-FGF), endothelin-1 (ET-1), nerve growth factor-beta (NGF-beta), interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), stem cell factor (SCF) were recorded. Three control groups were established accordingly. RESULTS: When the ratio between keratinocytes and Malassezia species was lower than 1: 10, the growth rate of keratinocytes was not affected by Malassezia (P > 0.05). When the ratio was increased above 1:20, the growth rate of keratinocytes was significantly inhibited by Malassezia (P < 0.01). The secretions of IL-1alpha, IL-6, TNF-alpha, and ET-1 was significantly increased after the co-culture of keratinocytes and Malassezia (P < 0.01), while those of b-FGF, NGF-beta, and SCF had no significant changes (P > 0.05). Compared with the isolates from the hypo-pigmentation area, ET-1 induced by isolate from hyperpigmentation area significantly increased (P < 0.01). CONCLUSION: When Malassezia isolates are co-cultured with keratinocytes, the secretions of cytokines associated with melanogenesis may differ from each other. ET-1 may play certain role in the hyper-pigmentation of pityriasis versicolor.