DNA methylation is a crucial epigenetic modification in the establishment of cell-type-specific characteristics. However, how DNA methylation is selectively reprogrammed at adipocyte-specific loci during adipogenesis remains unclear. Here, we show that the transcription factor, C/EBPδ, and the DNA methylation eraser, TET3, cooperatively control adipocyte differentiation. We perform whole-genome bisulfite sequencing to explore the dynamics and regulatory mechanisms of DNA methylation in adipocyte differentiation. During adipogenesis, DNA methylation selectively decreases at adipocyte-specific loci carrying the C/EBP binding motif, which correlates with the activity of adipogenic promoters and enhancers. Mechanistically, we find that C/EBPδ recruits a DNA methylation eraser, TET3, to catalyse DNA demethylation at the C/EBP binding motif and stimulate the expression of key adipogenic genes. Ectopic expression of TET3 potentiates in vitro and in vivo adipocyte differentiation and recovers downregulated adipogenic potential, which is observed in aged mice and humans. Taken together, our study highlights how targeted reprogramming of DNA methylation through cooperative action of the transcription factor C/EBPδ, and the DNA methylation eraser TET3, controls adipocyte differentiation.

DNA甲基化是建立细胞类型特异性特征的关键表观遗传修饰。然而，在脂肪生成过程中，DNA 甲基化如何在脂肪细胞特异性位点选择性重编程仍不清楚。在这里，我们表明转录因子 C/EBPδ 和 DNA 甲基化擦除器 TET3 协同控制脂肪细胞分化。我们进行全基因组亚硫酸氢盐测序，以探索 DNA 甲基化在脂肪细胞分化中的动力学和调控机制。在脂肪生成过程中，DNA 甲基化在携带 C/EBP 结合基序的脂肪细胞特异性位点选择性降低，这与脂肪形成启动子和增强子的活性相关。从机制上讲，我们发现 C/EBPδ 招募了一个 DNA 甲基化擦除器 TET3，催化 C/EBP 结合基序处的 DNA 去甲基化并刺激关键脂肪形成基因的表达。TET3 的异位表达增强体外和体内脂肪细胞分化并恢复下调的脂肪生成潜力，这在老年小鼠和人类中观察到。总之，我们的研究强调了通过转录因子 C/EBPδ 和 DNA 甲基化擦除器 TET3 的协同作用来靶向重编程 DNA 甲基化如何控制脂肪细胞分化。