Expression of neuronal markers suggests heterogeneity of chick sympathoadrenal cells prior to invasion of the adrenal anlagen
Expression of neuronal markers suggests heterogeneity of chick sympathoadrenal cells prior to invasion of the adrenal anlagen
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DOI：
10.1007/s00441-004-0996-1
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发表时间：
2005-01-01
影响因子：
3.6
通讯作者：
Unsicker, K
中科院分区：
文献类型：
--
作者：
Ernsberger, U;Esposito, L;Unsicker, K
我们分析了鸡胚肾上腺组织发育过程中神经嵴来源的前体细胞的分布以及儿茶酚胺和神经元标记物的表达。未分化的神经嵴细胞被发现在假定肾上腺区域从胚胎第3天（E3）向前。表达酪氨酸羟化酶（TH）mRNA的细胞比例的增加表明，不仅在初级交感神经节，而且在假定的肾上腺区域的前体细胞的儿茶酚胺能分化。而前体细胞和分化细胞显示间充质分布，直到E5，离散肾上腺原基的形式在E6。即使在E5，低或检测不到的神经丝M（NF-M）mRNA表达的儿茶酚胺能细胞占上风的位置，肾上腺原基在E6期间变得不同。在肾上腺组织的整个胚胎发生过程中，TH阳性和NF-M阴性细胞的优势得以维持。编码SCG 10的RNA是一种泛神经元标记物，如NF-M，在E6期间在整个肾上腺原基中强烈表达，但在E15时与神经元细胞相比，在嗜铬细胞中的水平降低。另外两种神经元标记物，synaptotagmin 1和neurexin 1，在整个胚胎发生过程中在嗜铬细胞中以低至不可检测的水平表达。神经元标记物的发育调节在所分析的四种mRNA中显示至少三种不同的模式。重要的是，在发育中的肾上腺原基中，神经元标记物没有普遍下调。因此，我们的观察问题的经典概念的嗜铬细胞分化从一个共同的交感肾上腺祖细胞表达神经元的特性，并建议替代模型与变化的指导性信号或单独的祖细胞群交感神经元和嗜铬内分泌细胞。
We have analyzed the distribution of neural crest-derived precursors and the expression of catecholaminergic and neuronal markers in developing adrenal tissue of chick embryos. Undifferentiated neural crest cells are found in presumptive adrenal regions from embryonic day 3 (E3) onward. An increasing proportion of cells expressing tyrosine hydroxylase (TH) mRNA indicates catecholaminergic differentiation of precursors not only in primary sympathetic ganglia, but also in presumptive adrenal regions. Whereas precursors and differentiating cells show mesenchymal distribution until E5, discrete adrenal anlagen form during E6. Even during E5, catecholaminergic cells with low or undetectable neurofilament M (NF-M) mRNA expression prevail in positions at which adrenal anlagen become distinct during E6. The predominance of TH-positive and NF-M-negative cells is maintained throughout embryogenesis in adrenal tissue. RNA encoding SCG10, a pan-neuronal marker like NF-M, is strongly expressed throughout adrenal anlagen during E6 but is found at reduced levels in chromaffin cells compared with neuronal cells at E15. Two additional neuronal markers, synaptotagmin 1 and neurexin 1, are expressed at low to undetectable levels in developing chromaffin cells throughout embryogenesis. The developmental regulation of neuronal markers shows at least three different patterns among the four mRNAs analyzed. Importantly, there is no generalized downregulation of neuronal markers in developing adrenal anlagen. Thus, our observations question the classical concept of chromaffin differentiation from a common sympathoadrenal progenitor expressing neuronal properties and suggest alternative models with changing instructive signals or separate progenitor populations for sympathetic neuronal and chromaffin endocrine cells.