Dead box helicase 5 (DDX5) is an RNA helicase that is has cellular function on RNA splicing and transcriptional regulation. It has been reported to be involved in cell differentiation including adipogenesis. However, it is not clear how DDX5 is regulated during adipogenesis. Our previous report demonstrated that the Ten-eleven translocation methyl-cytosine dioxygenase 2 (TET2) is required for adipogenesis. This study was aimed to investigate DDX5 as a direct target of TET2 upon adipogenic induction of 3T3-L1 preadipocyte. Microarray-based screening of differentially expressed genes upon TET2 knockdown identified genes involved in cell cycle, DNA replication, and ribosome biology as major targets of TET2 in the initial step of adipogenic induction. The Ddx5 gene was identified and validated as the target. TET2-mediated epigenetic regulation of the Ddx5 gene was measured by two independent methods including immunoprecipitation against 5-hydroxymethylcytosine (5hmC) and 5-methylcytosine (5mC) as well as EpiMark 5hmC and 5mC analysis. Ddx5 expression was downregulated upon TET2 knockdown, coincided with a significant decrease of 5hmC at the Ddx5 locus. DDX5 knockdown significantly suppressed adipogenesis, while DDX5 overexpression promoted it. Importantly, DDX5 overexpression, when co-transfected, rescued the process of adipogenesis, which was hindered by TET2 siRNA treatment. The findings suggest TET2-mediated regulation of the Ddx5 gene is required for an initial step of adipogenesis.

中文翻译：

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DEAD Box 解旋酶 5 在早期脂肪生成中的诱导受 10-11 易位 2 的调节。

死盒解旋酶 5 (DDX5) 是一种 RNA 解旋酶，对 RNA 剪接和转录调控具有细胞功能。据报道，它参与细胞分化，包括脂肪生成。然而，目前尚不清楚 DDX5 在脂肪生成过程中是如何调节的。我们之前的报告表明，脂肪生成需要 10-11 易位甲基胞嘧啶双加氧酶 2（TET2）。本研究旨在研究 DDX5 作为 TET2 在 3T3-L1 前脂肪细胞成脂诱导后的直接靶点。在 TET2 敲低时基于微阵列的差异表达基因筛选确定了涉及细胞周期、DNA 复制和核糖体生物学的基因，这些基因是 TET2 在脂肪生成诱导的初始步骤中的主要靶点。Ddx5 基因被鉴定并验证为目标。TET2 介导的 Ddx5 基因表观遗传调控通过两种独立的方法进行测量，包括针对 5-羟甲基胞嘧啶 (5hmC) 和 5-甲基胞嘧啶 (5mC) 的免疫沉淀以及 EpiMark 5hmC 和 5mC 分析。Ddx5 表达在 TET2 敲低后下调，与 Ddx5 基因座的 5hmC 显着降低一致。DDX5 敲低显着抑制脂肪生成，而 DDX5 过表达促进了脂肪生成。重要的是，DDX5 过表达，当共转染时，挽救了脂肪生成过程，而这一过程受到 TET2 siRNA 处理的阻碍。研究结果表明，脂肪生成的初始步骤需要 TET2 介导的 Ddx5 基因调控。