甲氧沙林对培养人表皮黑素细胞黑素合成的影响及信号转导的研究

Study on effects of melanogenesis induced by 8-methoxypsoralen and related signal transduction pathways in cultural epidermal melanocyte

目的:观察甲氧沙林(8～甲氧补骨脂素,8-MOP)对体外培养的人表皮黑素细胞黑素合成和酪氨酸酶活性的影响,并初步探讨8-MOP诱导表皮黑素细胞分化的信号转导途径。方法:采用4种浓度(10～500μmol/L)的8-MOP作用于体外培养的人表皮黑素细胞,观察不同浓度、不同时间8-MOP对黑素细胞的形态、增殖、酪氨酸酶活性、黑素含量的影响,并用放射免疫法测定8-MOP对细胞内环磷腺苷酸(cAMP)含量的影响。结果:100μmol/L 8-MOP作用黑素细胞120 h能显著促进酪氨酸酶的活性,提高黑素细胞的黑素含量,8-MOP抑制黑素细胞增殖和提高细胞内cAMP的水平呈浓度依赖性。结论:8-MOP在体外能直接刺激表皮黑素细胞的黑素合成,上述变化可能通过cAMP依赖的蛋白激酶(PK)A信号通路发挥作用。

Objective: To study the effects of 8-methoxypsoralen (8-MOP) on melanogenesis and tyrosinase activity in epidermal melanocytes, initially discuss the related way of signal transduction. Methods: Four different concentrations of 8-methoxypsoralen were incubated with epidermal melanocytes for 24h, 72h and 120h and then melanin content, tyrosinase activity were respectively measured. Radioimmunoassay was undertaken to observe the effects of 8-MOP on the intracellular levels of cAMP. Results: It showed that the epidermal melanocytes treated with 100μmol/L 8-MOP for 120h increased the activity of the tyrosinase and the level of melanin content most. The increasing level of intracellular cAMP and decreasing melanocyte proliferation were in a dose-dependent manner. Conclusions: 8-MOP may stimulate melanogenesis directly in epidermal melanocytes, which may be induced by the signal transduction of cAMP depended PKA pathway.