The m6A demethylase FTO promotes the osteogenesis of mesenchymal stem cells by downregulating PPARG
The m6A demethylase FTO promotes the osteogenesis of mesenchymal stem cells by downregulating PPARG
复制标题
m(6)A去甲基化酶FTO通过下调PPARG促进间充质干细胞的成骨
DOI：
10.1038/s41401-021-00756-8
复制
发表时间：
2021-08-30
影响因子：
8.2
通讯作者：
Shen，Juan
中科院分区：
文献类型：
--
作者：
Chen，Liu-shan;Zhang，Meng;Shen，Juan
N6-甲基腺苷（m6 A）是mRNA中最丰富的转录后甲基化修饰，调节哺乳动物发育和人类疾病中各种生物学过程的微调。本研究探讨m6 A修饰在骨髓间充质干细胞（mesenchymal stem cells，MSCs）成骨过程中的作用，以及m6 A修饰调控骨质疏松和骨坏死过程的可能机制。我们对骨质疏松和骨坏死患者的差异基因特征进行了系统分析，并进行了m6 A-RNA免疫沉淀（m6 A-RIP）测序，以确定参与骨生成的潜在调控基因。我们发现，脂肪量和肥胖（FTO），一个主要的m6 A脱甲基酶，在骨质疏松症和骨坏死患者中显著下调。在人MSC向成骨细胞分化的过程中，FTO显著上调。FTO的耗尽和FTO抑制剂FB 23或FB 23 -2的应用都损害了人MSC的成骨分化。敲除小鼠FTO导致骨密度降低和骨形成受损。PPARG是骨质疏松症的生物标志物，被确定为FTO的关键下游靶标。我们进一步揭示了FTO介导PPARG mRNA的3 'UTR中的m6 A去甲基化，并以YTHDF 1依赖的方式降低PPARG mRNA的稳定性。PPARG的过表达减轻了FTO介导的MSC的成骨分化，而PPARG的敲低促进了成骨细胞生物标志物ALPL和OPN在成骨分化过程中的FTO诱导的表达。总之，本研究证明了FTO-PPARG轴在促进人MSC成骨中的功能意义，并阐明了m6 A修饰在介导骨质疏松症和骨坏死中的作用。
N6-methyladenosine (m6A) is the most abundant posttranscriptional methylation modification that occurs in mRNA and modulates the fine-tuning of various biological processes in mammalian development and human diseases. In this study we investigated the role of m6A modification in the osteogenesis of mesenchymal stem cells (MSCs), and the possible mechanisms by which m6A modification regulated the processes of osteoporosis and bone necrosis. We performed systematic analysis of the differential gene signatures in patients with osteoporosis and bone necrosis and conducted m6A-RNA immunoprecipitation (m6A-RIP) sequencing to identify the potential regulatory genes involved in osteogenesis. We showed that fat mass and obesity (FTO), a primary m6A demethylase, was significantly downregulated in patients with osteoporosis and osteonecrosis. During the differentiation of human MSCs into osteoblasts, FTO was markedly upregulated. Both depletion of FTO and application of the FTO inhibitor FB23 or FB23-2 impaired osteogenic differentiation of human MSCs. Knockout of FTO in mice resulted in decreased bone mineral density and impaired bone formation. PPARG, a biomarker for osteoporosis, was identified as a critical downstream target of FTO. We further revealed that FTO mediated m6A demethylation in the 3’UTR of PPARG mRNA, and reduced PPARG mRNA stability in an YTHDF1-dependent manner. Overexpression of PPARG alleviated FTO-mediated osteogenic differentiation of MSCs, whereas knockdown of PPARG promoted FTO-induced expression of the osteoblast biomarkers ALPL and OPN during osteogenic differentiation. Taken together, this study demonstrates the functional significance of the FTO-PPARG axis in promoting the osteogenesis of human MSCs and sheds light on the role of m6A modification in mediating osteoporosis and osteonecrosis.