Effects of stem cell factor and extracellular matrix on melanocyte differentiation in mouse neural crest cell culture.

应用免疫组织化学技术和多巴比妥酸反应研究了可溶性干细胞因子(S-SCF)对培养的小鼠神经脊细胞(NCC)黑素细胞发育的影响。在S-SCF(50 ng/ml)持续存在的情况下，第3天可见c-KIT(+)树突状细胞，第9天达到高峰，而未加入S-SCF的第9天已无阳性细胞。当加入S-SCF第5天及以后，未见c-KIT(+)细胞。在S-SCF培养的NCC中，第9天就出现了酪氨酸酶、Trp1和Trp2阳性细胞，提示SCF可能在c-Kit(+)细胞的发育过程中起一定作用，S-SCF有一个诱导c-kit(+)细胞DOPA阳性黑素细胞的关键时间(0-5天)，但在S-SCF外植体培养中没有发现成熟的黑素细胞，而加入霍乱毒素(CT)后，S-SCF对DOPA阳性黑素细胞的形成和向成熟黑素细胞分化的作用明显增强。提示CT等其他因素可能是诱导分化为成熟黑素细胞所必需的。

We investigated the role of soluble stem cell factor (s-SCF) in the melanocyte development of cultured mouse neural crest cells (NCC) by using immunohistochemical techniques and DOPA reaction. c-KIT (+) dendritic cells were found on Day 3 of the explant culture with continuous presence of s-SCF (50ng/ml) and reached a plateau after Day 9, while there were no positive cells left at Day 9 without s-SCF.When s-SCF was added on Day 5 or after, c-KIT (+) cells did not appear. Tyrosinase, TRP1, and TRP2 positive cells all appeared by Day 9 in cultured NCC with s-SCF.These results suggest that SCF may play a role in the development of c-KiIT (+) cells and that there is a critical time (Days 0-5) when s-SCF must be added to induce c-KIT (+) cells DOPA positive melanocytes but no mature melanocytes were found in the explant culture with s-SCF,while the effects of s-SCF on both DOPA positive melanocyte appearance and the differentiation into mature melanocytes were markedly enhanced by the addition of cholera toxin (CT) to the culture. It is indicated that additional factors, such as CT,may be necessary to induce the differentiation into mature melanocytes.