The role of stem cell factor in the development of melanocytes with regard to c-KIT and tyrosinase expression.

我们和其他人以前报道，可溶性干细胞因子（sSCF）和c-KIT的相互作用在黑素细胞从神经嵴细胞（NCC）的发展中起着重要的作用。内皮素-3（ET-3）不仅促进NCC的增殖，而且促进NCC的分化。在这项研究中，为了确定ET-3与sSCF组合对培养的NCC增殖和向黑素细胞分化的影响，我们将来自野生型和'Steel'突变小鼠的NCC与ET-3、sSCF或ET-3+sSCF培养3-15天。免疫组化和DOPA染色后，计数c-KIT（+）和DOPA（+）细胞数。在野生型中，加入ET-3以剂量和时间依赖的方式增加c-KIT（+）和DOPA（+）细胞的数量，而加入sSCF主要增加c-KIT（+）细胞的数量。ET-3可检测到黑素细胞的着色，而sSCF则不能检测到，联合应用ET-3可使c-KIT（+）、DOPA（+）细胞和黑素细胞的着色明显增加。在“Steel”突变小鼠中，所有这三种细胞都没有出现在与ET-3一起培养的NCC中，尽管当SCF和ET-3都加入到“Steel”NCC中时检测到色素沉着的黑素细胞。这些结果表明，在野生型NCC外植体中存在固有的SCF来源，并且SCF支持的c-KIT（+）黑素细胞增殖物的存活对于ET-3加速黑化是必不可少的。

We and others previously reported that soluble stem cell factor (sSCF) and c-KIT interaction plays an important role in the development of melanocytes from neural crest cells (NCCs). It has also been shown that endothelin-3 (ET-3) promotes not only proliferation but also differentiation of NCCs. In this study, to determine the effects of ET-3 in combination with sSCF on the proliferation and differentiation of cultured NCCs into melanocytes, we cultured NCCs from wild type and 'Steel' mutant mice with ET-3, sSCF or ET-3+sSCF for 3-15 days. After immunohistochemical and DOPA staining, we counted the number of c-KIT(+) and DOPA(+) cells. In the wild type, the addition of ET-3 increased the number of c-KIT(+) and DOPA(+) cells in a dose- and time- dependent manner, while the addition of sSCF mainly increased the number of c-KIT(+) cells. Pigmented melanocytes were detected with ET-3 but not with sSCF.The combination with sSCF and ET-s showed a marked increase of c-KIT(+), DOPA(+) cells and pigmented melanocytes. In 'Steel' mutant mice, all those three cells did not appear in NCCs cultured with ET-3, although pigmented melanocytes were detected when SCF and ET-3 were both added to 'Steel' NCCs. These results suggest that there are intrinsic SCF sources in the wild type NCC explants, and that the survival of c-KIT(+) melanocyte precursers supported by SCF is essential to the acceleration of melanization by ET-3.