Inhibition of methylation decreases osteoblast differentiation via a non-DNA-dependent methylation mechanism
Inhibition of methylation decreases osteoblast differentiation via a non-DNA-dependent methylation mechanism
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DOI：
10.1016/j.bone.2009.09.033
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发表时间：
2010-02-01
期刊：
影响因子：
4.1
通讯作者：
Steegenga, Wilma T.
中科院分区：
文献类型：
--
作者：
Vaes, Bart L. T.;Lute, Carolien;Steegenga, Wilma T.
人们很快发现，包括 DNA 和蛋白质在内的生物分子的 S-腺苷甲硫氨酸 (SAM) 依赖性甲基化是细胞过程调节的关键机制。我们通过使用高碘酸氧化腺苷 (ADOX)（一种 SAM 依赖性甲基转移酶抑制剂）研究了 SAM 依赖性甲基化减少对成骨细胞分化的影响。在非成骨控制条件下和生长因子诱导分化过程中分析了该试剂调节成骨细胞分化的能力，并与 5-Aza-2'-脱氧胞苷 (5-Aza-CdR) 抑制 DNA 甲基化的效果进行了比较。在不应用特定的成骨触发因素的情况下，ADOX 和 5-Aza-CdR 均诱导小鼠 C2C12 细胞中成骨细胞标志物 Alp、Osx 和 Ocn 的 mRNA 表达。在成骨条件下，ADOX 抑制人间充质干细胞和 C2C12 细胞的分化。在骨形态发生蛋白2诱导的C2C12成骨细胞分化过程中，早期（Msx2、Dlx5、Runx2）和晚期（Alp、Osx、Ocn）成骨细胞标志物的基因表达分析表明，ADOX仅降低晚期Runx2靶基因的表达。通过使用 Runx2 响应性荧光素酶报告基因 (6xOSE)，我们发现 ADOX 降低了 Runx2 的活性，而 5-Aza-CdR 则没有影响。综上所述，我们的数据表明，SAM 依赖性甲基转移酶活性降低会通过非 DNA 依赖性甲基化机制导致成骨细胞分化受损，并且甲基化是 Runx2 控制的基因表达的调节因子。 (C) 2009 Elsevier Inc. 保留所有权利。
S-adenosylmethionine (SAM)-dependent methylation of biological molecules including DNA and proteins is rapidly being uncovered as a critical mechanism for regulation of cellular processes. We investigated the effects of reduced SAM-dependent methylation on osteoblast differentiation by using periodate oxidized adenosine (ADOX), an inhibitor of SAM-dependent methyltransferases. The capacity of this agent to modulate osteoblast differentiation was analyzed under non-osteogenic control conditions and during growth factor-induced differentiation and compared with the effect of inhibition of DNA methylation by 5-Aza-2'-deoxycytidine (5-Aza-CdR). Without applying specific osteogenic triggers, both ADOX and 5-Aza-CdR induced mRNA expression of the osteoblast markers Alp, Osx, and Ocn in murine C2C12 cells. Under osteogenic conditions, ADOX inhibited differentiation of both human mesenchymal stem cells and C2C12 cells. Gene expression analysis of early (Msx2, Dlx5, Runx2) and late (Alp, Osx, Ocn) osteoblast markers during bone morphogenetic protein 2-induced C2C12 osteoblast differentiation revealed that ADOX only reduced expression of the late phase Runx2 target genes. By using a Runx2-responsive luciferase reporter (6xOSE), we showed that ADOX reduced the activity of Runx2, while 5-Aza-CdR had no effect. Taken together, our data suggest that decreased SAM-dependent methyl transferase activity leads to impaired osteoblast differentiation via non-DNA-dependent methylation mechanisms and that methylation is a regulator of Runx2-controlled gene expression. (C) 2009 Elsevier Inc. All rights reserved.