Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
Proc Natl Acad Sci U S A. 2011 Sep 6;108(36):14843-8. doi: 10.1073/pnas.1110236108. Epub 2011 Aug 22.
The mesenchymal cell is a multipotent stem cell with the capacity to give rise to multiple cell types such as adipocytes, osteoblasts, chondrocytes, and myocytes. However, the molecular events responsible for their lineage specification and differentiation remain obscure. Here we show that inactivation of chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII), a member of the nuclear receptor superfamily, in mesenchymal progenitors favors osteoblast and myoblast development while simultaneously impairing adipogenic and chondrogenic programs. During mouse embryogenesis, COUP-TFII protein is highly detected in the mesenchymal compartment and is involved in mesoderm tissue formation. Ablation of COUP-TFII in mice led to higher bone density, increased muscle mass, and suppression of cartilage and fat formation. We further demonstrate that COUP-TFII directs the plasticity of mesenchymal precursors primarily through the combined modulation of Wnt signaling, Runx2 activity, as well as PPARγ and Sox9 expression. Together, our results provide insight into the mechanisms whereby a single nuclear receptor can fine-tune the lineage-specific differentiation of a progenitor cell.
间质细胞是一种多能干细胞,具有分化为多种细胞类型的能力,如脂肪细胞、成骨细胞、软骨细胞和肌细胞。然而,导致其谱系特化和分化的分子事件仍然不清楚。在这里,我们表明鸡卵清蛋白上游启动子转录因子 II(COUP-TFII)的失活,该基因属于核受体超家族的成员,在间质祖细胞中有利于成骨细胞和肌细胞的发育,同时损害脂肪细胞和成软骨细胞的分化程序。在小鼠胚胎发生过程中,COUP-TFII 蛋白在间质细胞中高度表达,并参与中胚层组织的形成。在小鼠中敲除 COUP-TFII 导致骨密度增加、肌肉质量增加以及软骨和脂肪形成的抑制。我们进一步证明 COUP-TFII 通过对 Wnt 信号、Runx2 活性以及 PPARγ 和 Sox9 表达的综合调节,指导间质前体细胞的可塑性。总之,我们的研究结果为单个核受体如何精细调节祖细胞的谱系特异性分化提供了深入的见解。