State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, People's Republic of China; Department of Oral & Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, People's Republic of China.
Stem Cells. 2014 Feb;32(2):510-20. doi: 10.1002/stem.1549.
The differentiation of adipose tissue-derived stromal cells (ADSCs) into adipocytes involves a highly orchestrated series of events that includes cell lineage commitment, mitotic clonal expansion, growth arrest, and terminal differentiation. However, the molecular mechanisms controlling adipogenesis are not yet completely understood. In this study, we investigated whether microRNAs (miRNAs) play a role in adipocyte differentiation. Microarray analysis was performed to determine the miRNA expression profile during ADSC differentiation, and miR-363 was found to be one of the most significantly downregulated miRNAs. We show that the overexpression of miR-363 in ADSCs inhibited mitotic clonal expansion and terminal differentiation. Furthermore, ectopic introduction of miR-363 into ADSCs markedly reduced the levels of E2F3, a key transcription factor that regulates growth and proliferation during mitotic clonal expansion. Finally, using an EGFP/RFP reporter assay, we demonstrate that miR-363 can directly target the 3'UTR of E2F3. Taken together, these results suggest that miR-363 regulates the transition from mitotic clonal expansion to terminal differentiation during adipogenesis in ADSCs, at least in part, by targeting E2F3.
脂肪组织来源的基质细胞（ADSCs）分化为脂肪细胞涉及一系列高度协调的事件，包括细胞谱系决定、有丝分裂克隆扩增、生长停滞和终末分化。然而，控制脂肪生成的分子机制尚不完全清楚。在这项研究中，我们研究了 microRNAs（miRNAs）是否在脂肪细胞分化中发挥作用。进行了微阵列分析以确定 ADSC 分化过程中的 miRNA 表达谱，发现 miR-363 是下调最显著的 miRNA 之一。我们表明，ADSCs 中 miR-363 的过表达抑制有丝分裂克隆扩增和终末分化。此外，异位引入 miR-363 到 ADSCs 中显著降低了 E2F3 的水平，E2F3 是调节有丝分裂克隆扩增期间生长和增殖的关键转录因子。最后，使用 EGFP/RFP 报告基因测定，我们证明 miR-363 可以直接靶向 E2F3 的 3'UTR。总之，这些结果表明，miR-363 通过靶向 E2F3 调节 ADSC 脂肪生成过程中从有丝分裂克隆扩增到终末分化的转变，至少部分如此。
