Department of Environmental Health, University of Cincinnati College of Medicine, 3223 Eden Avenue, Kettering Laboratory, Suite 410, P.O. Box 670056, Cincinnati, OH 45267-0056, USA.
Dev Biol. 2013 Feb 1;374(1):96-107. doi: 10.1016/j.ydbio.2012.11.020. Epub 2012 Nov 30.
Embryonic eyelid closure involves forward movement and ultimate fusion of the upper and lower eyelids, an essential step of mammalian ocular surface development. Although its underlying mechanism of action is not fully understood, a functional mitogen-activated protein kinase kinase kinase 1 (MAP3K1) is required for eyelid closure. Here we investigate the molecular signatures of MAP3K1 in eyelid morphogenesis. At mouse gestational day E15.5, the developmental stage immediately prior to eyelid closure, MAP3K1 expression is predominant in the eyelid leading edge (LE) and the inner eyelid (IE) epithelium. We used laser capture microdissection (LCM) to obtain highly enriched LE and IE cells from wild type and MAP3K1-deficient fetuses and analyzed genome-wide expression profiles. The gene expression data led to the identification of three distinct developmental features of MAP3K1. First, MAP3K1 modulated Wnt and Sonic hedgehog signals, actin reorganization, and proliferation only in LE but not in IE epithelium, illustrating the temporal-spatial specificity of MAP3K1 in embryogenesis. Second, MAP3K1 potentiated AP-2α expression and SRF and AP-1 activity, but its target genes were enriched for binding motifs of AP-2α and SRF, and not AP-1, suggesting the existence of novel MAP3K1-AP-2α/SRF modules in gene regulation. Third, MAP3K1 displayed variable effects on expression of lineage specific genes in the LE and IE epithelium, revealing potential roles of MAP3K1 in differentiation and lineage specification. Using LCM and expression array, our studies have uncovered novel molecular signatures of MAP3K1 in embryonic eyelid closure.
胚胎眼睑闭合涉及上、下眼睑的向前运动和最终融合，这是哺乳动物眼表面发育的一个关键步骤。尽管其作用机制尚未完全了解，但功能性丝裂原活化蛋白激酶激酶激酶 1（MAP3K1）是眼睑闭合所必需的。在这里，我们研究了 MAP3K1 在眼睑形态发生中的分子特征。在小鼠胚胎第 15.5 天，即眼睑闭合前的发育阶段，MAP3K1 表达主要在上眼睑前缘（LE）和内眼睑（IE）上皮细胞中。我们使用激光捕获显微切割（LCM）从野生型和 MAP3K1 缺陷型胎儿中获得高度富集的 LE 和 IE 细胞，并分析了全基因组表达谱。基因表达数据导致了对 MAP3K1 的三个不同发育特征的鉴定。首先，MAP3K1 仅在 LE 中调节 Wnt 和 Sonic hedgehog 信号、肌动蛋白重组和增殖，而不在 IE 上皮细胞中，这说明了 MAP3K1 在胚胎发生中的时空特异性。其次，MAP3K1 增强了 AP-2α 的表达和 SRF 和 AP-1 的活性，但它的靶基因富含 AP-2α 和 SRF 的结合基序，而不是 AP-1，这表明在基因调控中存在新的 MAP3K1-AP-2α/SRF 模块。第三，MAP3K1 对 LE 和 IE 上皮细胞中谱系特异性基因的表达有不同的影响，揭示了 MAP3K1 在分化和谱系特化中的潜在作用。使用 LCM 和表达数组，我们的研究揭示了 MAP3K1 在胚胎眼睑闭合中的新的分子特征。
