Spine Center, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China.
Department of Orthopedic Surgery, The Affiliated People's Hospital of Jiangsu University, Zhenjiang, 212002, Jiangsu, China.
Cell Death Dis. 2021 Nov 12;12(11):1078. doi: 10.1038/s41419-021-04312-4.
N6-methyladenosine (mA) is required for differentiation of human bone marrow mesenchymal stem cells (hBMSCs). However, its intrinsic mechanisms are largely unknown. To identify the possible role of mA binding protein YTHDF1 in hBMSCs osteogenesis in vivo, we constructed Ythdf1 KO mice and showed that depletion of Ythdf1 would result in decreased bone mass in vivo. Both deletion of Ythdf1 in mouse BMSCs and shRNA-mediated knockdown of YTHDF1 in hBMSCs prevented osteogenic differentiation of cells in vitro. Using methylated RNA immunoprecipitation (Me-RIP) sequencing and RIP-sequencing, we found that ZNF839 (a zinc finger protein) served as a target of YTHDF1. We also verified its mouse homolog, Zfp839, was translationally regulated by Ythdf1 in an mA-dependent manner. Zfp839 potentiated BMSC osteogenesis by interacting with and further enhancing the transcription activity of Runx2. These findings should improve our understanding of the mechanism of BMSC osteogenesis regulation and provide new ideas for the prevention and treatment of osteoporosis.
N6-甲基腺苷（mA）是人类骨髓间充质干细胞（hBMSCs）分化所必需的。然而，其内在机制在很大程度上尚不清楚。为了鉴定 mA 结合蛋白 YTHDF1 在体内 hBMSCs 成骨中的可能作用，我们构建了 Ythdf1 KO 小鼠，并表明 Ythdf1 的耗竭会导致体内骨量减少。在小鼠 BMSCs 中删除 Ythdf1 以及在 hBMSCs 中通过 shRNA 介导的 YTHDF1 敲低都可防止细胞体外成骨分化。通过甲基化 RNA 免疫沉淀（Me-RIP）测序和 RIP 测序，我们发现 ZNF839（一种锌指蛋白）是 YTHDF1 的靶标。我们还验证了其小鼠同源物 Zfp839 可通过 Ythdf1 以 mA 依赖性方式进行翻译调控。Zfp839 通过与 Runx2 相互作用并进一步增强其转录活性来增强 BMSC 成骨作用。这些发现应能增进我们对 BMSC 成骨调控机制的理解，并为骨质疏松症的预防和治疗提供新的思路。
