Wnt7b-induced Sox11 functions enhance self-renewal and osteogenic commitment of bone marrow mesenchymal stem cells
Wnt7b-induced Sox11 functions enhance self-renewal and osteogenic commitment of bone marrow mesenchymal stem cells
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Wnt7b诱导的Sox11功能增强骨髓间充质干细胞的自我更新和成骨承诺
DOI：
10.1002/stem.3192
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发表时间：
2020-05-04
期刊：
影响因子：
5.2
通讯作者：
Ye, Ling
中科院分区：
文献类型：
--
作者：
Yu, Fanyuan;Wu, Fanzi;Ye, Ling
作为一个深刻的骨合成代谢调节剂，Wnt 7 b是公认的增强成骨细胞的活动。在这里，我们报告了骨髓间充质干细胞（BMSC）是另一个重要的群体响应Wnt 7 b。在这项研究中，我们系统地研究了Wnt 7 b在BMSCs中的体内作用，使用转基因小鼠，高通量RNA-seq，免疫组织化学，RT-qPCR和原位杂交。这些方法使我们发现Sox 11是通过Wnt 7 b在BMSCs中诱导的。采用集落形成实验、流式细胞术、EdU掺入法、RT-qPCR和Western blot检测BMSCs的自我更新能力。采用碱性磷酸酶染色、茜素红染色及体外移植的方法检测BMSCs的成骨能力。ChIP-qPCR、shRNA和免疫荧光染色用于研究潜在机制。因此，发现骨来源的Wnt 7 b在骨质疏松症中减少，在骨折愈合中升高。在骨折愈合过程中，Wnt 7 b特别在愈合边界内的间充质细胞中表达。Wnt 7 b过表达骨骼的RNA-seq数据揭示了Sox 11的显著上调。组织学结果进一步揭示了Sox 11在BMSCs中特异性增加。Wnt 7 b诱导的Sox 11被证明可以增强BMSC的自我更新和成骨分化。Wnt 7 b激活Ca 2+依赖性Nfatc 1信号传导，直接诱导Sox 11转录，进而激活BMSCs中增殖相关转录因子（Ccnb 1和Sox 2）和成骨相关因子（Runx 2，Sp 7）的转录。有趣的是，BMSC中的Wnt 7 b-Sox 11信号转导是不依赖于β-连环蛋白的。总之，本研究提供了Wnt 7 b在骨形成中的全新见解，即Wnt 7 b可以通过诱导Sox 11增强BMSCs的自我更新和成骨分化。这些发现提出了BMSCs中Wnt和Sox信号之间的新串扰。
As a profoundly anabolic regulator of bone, Wnt7b is well acknowledged to enhance osteoblast activities. Here, we report that bone marrow mesenchymal stem cells (BMSCs) are another important populations responding to Wnt7b. In this study, we systematically investigate the in vivo role of Wnt7b in BMSCs using transgenic mice, high-throughput RNA-seq, immunohistochemistry, RT-qPCR, and in situ hybridization. These methods lead us to uncover that Sox11 is induced via Wnt7b in BMSCs. Colony formation assay, flow cytometry, EdU incorporation labeling, RT-qPCR, and Western blot are conducted to detect the self-renewal capacity of BMSCs. Alkaline phosphatase staining, alizarin red staining, and ex vivo BMSCs transplantation are utilized to detect the osteogenic ability of BMSCs. ChIP-qPCR, shRNAs, and immunofluorescence staining are utilized to investigate underlying mechanisms. Consequently, bone-derived Wnt7b is found to decrease in osteoporosis and elevate in bone fracture healing. During bone fracture healing, Wnt7b is particularly expressed in the mesenchymal cells residing within healing frontiers. RNA-seq data of Wnt7b-overexpressed bones uncover the significant upregulation of Sox11. Histological results further unveil that Sox11 is specifically increased in BMSCs. Wnt7b-induced Sox11 is demonstrated to reinforce both self-renewal and osteogenic differentiation of BMSCs. Mechanistically, Wnt7b activates the Ca2+-dependent Nfatc1 signaling to directly induce Sox11 transcription, which in turn activates the transcriptions of both proliferation-related transcription factors (Ccnb1 and Sox2) and osteogenesis-related factors (Runx2, Sp7) in BMSCs. It is intriguing that this Wnt7b-Sox11 signaling in BMSCs is beta-Catenin-independent. Overall, this study provides brand new insights of Wnt7b in bone formation, namely, Wnt7b can enhance both self-renewal and osteogenic differentiation of BMSCs via inducing Sox11. These findings present a new crosstalk between Wnt and Sox signaling in BMSCs.