Department of Paediatrics, Affiliated Maternity and Child Health Care Hospital of Nantong University, Nantong, China.
Department of Orthopedic Surgery, Affiliated Taian City Central Hospital of Qingdao University, Taian, Shandong, China.
J Cell Biochem. 2023 Nov;124(11):1835-1847. doi: 10.1002/jcb.30492. Epub 2023 Oct 26.
Excess glucocorticoids (GCs) have been reported as key factors that impair osteoblast (OB) differentiation and function. However, the role of RNA N6-methyladenosine (m A) in this process has not yet been elucidated. In this study, we report that both the mRNA and protein expression of fat mass and obesity-associated gene (FTO), a key m A demethylase, were dose-dependently downregulated during OB differentiation by dexamethasone (DEX) in bone marrow mesenchymal stem cells (BMSCs), and FTO was gradually increased during OB differentiation. Meanwhile, FTO knockdown suppressed OB differentiation and mineralization, whereas overexpression of wide-type FTO, but not mutant FTO (mutated m A demethylase active site), reversed DEX-induced osteogenesis impairment. Interfering with FTO inhibited proliferation and the expression of Ki67 and Pcna in BMSCs during OB differentiation, whereas forced expression of wide-type FTO improved DEX-induced inhibition of BMSCs proliferation. Moreover, FTO knockdown reduced the mRNA stability of the OB marker genes Alpl and Col1a1, and FTO-modulated OB differentiation via YTHDF1 and YTHDF2. In conclusion, our results suggest that FTO inhibits the GCs-induced OB differentiation and function of BMSCs.
过量的糖皮质激素（GCs）被认为是损害成骨细胞（OB）分化和功能的关键因素。然而，RNA N6-甲基腺苷（m A）在这个过程中的作用尚未阐明。在本研究中，我们报告说，在骨髓间充质干细胞（BMSCs）中，地塞米松（DEX）通过剂量依赖性地下调脂肪量和肥胖相关基因（FTO）的 mRNA 和蛋白表达，FTO 是一种关键的 m A 去甲基化酶，并且在 OB 分化过程中逐渐增加。同时，FTO 敲低抑制 OB 分化和矿化，而过表达野生型 FTO（突变 m A 去甲基化酶活性位点）则逆转了 DEX 诱导的成骨作用受损。在 OB 分化过程中，干扰 FTO 抑制了 BMSCs 的增殖和 Ki67 和 Pcna 的表达，而过表达野生型 FTO 则改善了 DEX 诱导的 BMSCs 增殖抑制。此外，FTO 敲低降低了 OB 标记基因 Alpl 和 Col1a1 的 mRNA 稳定性，并且 FTO 通过 YTHDF1 和 YTHDF2 调节 OB 分化。总之，我们的研究结果表明，FTO 抑制了 GCs 诱导的 BMSCs 中 OB 的分化和功能。
