METTL3 Modulates Osteoclast Differentiation and Function by Controlling RNA Stability and Nuclear Export
METTL3 Modulates Osteoclast Differentiation and Function by Controlling RNA Stability and Nuclear Export
复制标题
DOI：
10.3390/ijms21051660
复制
发表时间：
2020-03-01
影响因子：
5.6
通讯作者：
Xu, Qiong
中科院分区：
文献类型：
--
作者：
Li, Di;Cai, Luhui;Xu, Qiong
破骨细胞的分化和功能对于维持骨稳态和保持骨骼完整性至关重要。N6-甲基腺苷（m（6）A）是一种丰富的mRNA修饰，最近已被证明在调节细胞谱系分化方面很重要。然而，m（6）A对破骨细胞分化的影响仍不清楚。在本研究中，我们观察到在破骨细胞分化过程中，m（6）A水平和甲基转移酶L3表达增加。Mettl 3敲低导致破骨细胞的大小增加，但骨吸收能力降低。Mettl 3缺失抑制破骨细胞特异性基因（Nfatc 1、c-Fos、Ctsk、Acp 5和Dcstamp）的表达，而细胞融合特异性基因Atp 6v 0 d2的表达上调。从机制上讲，Mettl 3敲低提高了Atp 6v 0 d2的mRNA稳定性，当沉默m（6）A结合蛋白YTHDF 2时也得到了相同的结果。此外，Mettl 3缺乏时，MAPK、NF-κ B和PI 3 K-AKT信号通路中关键分子的磷酸化水平降低。Mettl 3的缺失维持了Traf 6 mRNA在细胞核中的保留，并降低了TRAF 6的蛋白水平。综上所述，我们的数据表明，胃L3通过不同的机制调节破骨细胞的分化和功能，包括Atp 6v 0 d2 mRNA降解介导的YTHDF 2和Traf 6 mRNA核输出。这些发现阐明了破骨细胞发育中RNA表观遗传调控的分子基础。
Osteoclast differentiation and function are crucial for maintaining bone homeostasis and preserving skeletal integrity. N6-methyladenosine (m(6)A) is an abundant mRNA modification that has recently been shown to be important in regulating cell lineage differentiation. Nevertheless, the effect of m(6)A on osteoclast differentiation remains unknown. In the present study, we observed that the m(6)A level and methyltransferase METTL3 expression increased during osteoclast differentiation. Mettl3 knockdown resulted in an increased size but a decreased bone-resorbing ability of osteoclasts. The expression of osteoclast-specific genes (Nfatc1, c-Fos, Ctsk, Acp5 and Dcstamp) was inhibited by Mettl3 depletion, while the expression of the cellular fusion-specific gene Atp6v0d2 was upregulated. Mechanistically, Mettl3 knockdown elevated the mRNA stability of Atp6v0d2 and the same result was obtained when the m(6)A-binding protein YTHDF2 was silenced. Moreover, the phosphorylation levels of key molecules in the MAPK, NF-kappa B and PI3K-AKT signaling pathways were reduced upon Mettl3 deficiency. Depletion of Mettl3 maintained the retention of Traf6 mRNA in the nucleus and reduced the protein levels of TRAF6. Taken together, our data suggest that METTL3 regulates osteoclast differentiation and function through different mechanisms involving Atp6v0d2 mRNA degradation mediated by YTHDF2 and Traf6 mRNA nuclear export. These findings elucidate the molecular basis of RNA epigenetic regulation in osteoclast development.