Neuroscience Section, Department of Pediatrics, Papé Family Pediatric Research Institute, Oregon Health and Science University, Portland, OR 97239, USA.
Proc Natl Acad Sci U S A. 2012 Feb 28;109(9):3383-8. doi: 10.1073/pnas.1114515109. Epub 2012 Feb 16.
Combinatorial transcription codes generate the myriad of cell types during development and thus likely provide crucial insights into directed differentiation of stem cells to a specific cell type. The LIM complex composed of Isl1 and Lhx3 directs the specification of spinal motor neurons (MNs) in embryos. Here, we report that Isl1-Lhx3, a LIM-complex mimicking fusion, induces a signature of MN transcriptome and concomitantly suppresses interneuron differentiation programs, thereby serving as a potent and specific inducer of MNs in stem cells. We show that an equimolar ratio of Isl1 and Lhx3 and the LIM domain of Lhx3 are crucial for generating MNs without up-regulating interneuron genes. These led us to design Isl1-Lhx3, which maintains the desirable 1:1 ratio of Isl1 and Lhx3 and the LIM domain of Lhx3. Isl1-Lhx3 drives MN differentiation with high specificity and efficiency in the spinal cord and embryonic stem cells, bypassing the need for sonic hedgehog (Shh). RNA-seq analysis revealed that Isl1-Lhx3 induces the expression of a battery of MN genes that control various functional aspects of MNs, while suppressing key interneuron genes. Our studies uncover a highly efficient method for directed MN generation and MN gene networks. Our results also demonstrate a general strategy of using embryonic transcription complexes for producing specific cell types from stem cells.
组合转录代码在发育过程中产生了无数的细胞类型，因此可能为定向诱导干细胞分化为特定细胞类型提供了关键的见解。由 Isl1 和 Lhx3 组成的 LIM 复合物指导胚胎中脊髓运动神经元 (MNs) 的特化。在这里，我们报告说，Isl1-Lhx3，一种模拟融合的 LIM 复合物，诱导 MN 转录组的特征，并同时抑制中间神经元分化程序，从而成为干细胞中 MN 的有效和特异性诱导物。我们表明，Isl1 和 Lhx3 的等摩尔比以及 Lhx3 的 LIM 结构域对于在不上调中间神经元基因的情况下产生 MN 至关重要。这使我们设计了 Isl1-Lhx3，它保持了 Isl1 和 Lhx3 的理想 1:1 比例以及 Lhx3 的 LIM 结构域。Isl1-Lhx3 在脊髓和胚胎干细胞中以高特异性和高效率驱动 MN 分化，无需 Sonic Hedgehog (Shh)。RNA-seq 分析显示，Isl1-Lhx3 诱导一系列控制 MN 各种功能方面的 MN 基因的表达，同时抑制关键的中间神经元基因。我们的研究揭示了一种高效的定向 MN 生成和 MN 基因网络的方法。我们的结果还证明了一种使用胚胎转录复合物从干细胞中产生特定细胞类型的一般策略。
