lnc-dPRDM16在棕色脂肪发育与功能的研究

As the population of obesity is rising, there is an upsurge of the interest in brown adipocyte biology because of its unique energy expenditure feature and the recent discovery of brown adipose tissue (BAT) in human adults. Recent findings from other and our groups have revealed long non-coding RNAs (lncRNAs) as novel regulators in adipocyte lineage-specific development, but the role of lncRNA in human BAT development remain largely unknown and the function of lncRNAs in BAT in vivo has yet to be established. In our preliminary study, we have constructed a de novo human adipose tissue lncRNA catalogue (3,149 lncRNA) by RNA-seq and a computational pipeline. We identified 318 lncRNAs conserved between human and mouse and one of the top candidates is lnc-dPRDM16 that is enriched in BAT, transcribed divergently from PRDM16 promoter and tightly correlated with PRDM16 in both mouse and human adipose tissues. We have performed loss-of-function study in primary brown adipocyte culture with retroviral shRNA and shown that this lncRNA is required for brown adipocyte differentiation. We hypothesize that lnc-PRDM16 is an essential regulator during brown adipocyte development. To test this hypothesis, we have generated a lnc-dPRDM16 null mouse by inserting a transcription stop cassette to inactivate lnc-dPRDM16’s transcription. In this proposal, we aim to determine the role of lnc-dPRDM16 in brown fat development in vivo using this mouse model and test its function in human BAT cell culture. Accomplishment of the proposed experiments will shed a light on the lncRNA-mediated regulation of human brown adipocyte differentiation and fully establish the role of a conserved lncRNA, lnc-dPRDM16, in brown fat development and energy homeostasis in vivo.

随着肥胖人群数量的增加，以棕色脂肪组织发育和功能调控为靶标的治疗策略越来越受关注。长链非编码RNA是脂肪细胞发育调控的一类新的因子, 然而，lncRNA在人棕色脂肪发育中的功能仍不清楚。另外，在体内对lncRNA在棕色脂肪发育的研究尚无先例。在前期工作中，我们鉴定出了一个新的人与小鼠保守的lncRNA, lnc-dPRDM16。它从Prdm16启动子反方向转录, 与Prdm16表达谱紧密关联。小鼠前体棕色脂肪细胞的敲降实验证明它是棕色脂肪细胞的分化所必需的调控因子。基于这些工作，我们假设lnc-dPRDM16是棕色脂肪发育和功能的重要调控因子。本项目拟利用基因失活小鼠，研究它在棕色脂肪发育与能量代谢中的功能。我们也会用前期建立的人类棕色脂肪细胞培养系统来研究该基因的调控功能。该研究将阐明lnc-dPRDM16在人和小鼠的棕色脂肪细胞发育调控功能，为人类治疗肥胖症提供新思路。

在经费下达后，根据研究计划及实际研究调整，基本按时完成了项目的主要内容，我们也得到了一些重要的研究结果，发表了相关的研究论文。研究工作主要是（1）利用小鼠模型研究体内lnc-dPRDM16在棕色脂肪发育和能量代谢中的作用；2）研究lnc-dPRDM16在人棕色脂肪细胞分化与功能的作用。我们利用lnc-dPRDM16基因失活小鼠模型，具体开展以下几方面的工作：A) lnc-dPRDM16基因失活对棕色脂肪细胞发育的影响；B）lnc-dPRDM16基因失活棕色脂肪细胞脂质代谢的影响；C）lnc-dPRDM16基因失活对棕色脂肪细胞基因表达的影响；D）lnc-dPRDM16基因失活对高脂饲喂诱导的肥胖的影响。我们的研究结果表明了lnc-dPRDM16是棕色脂肪细胞发育与功能的重要调节因子,为将来以棕色脂肪组织发育调控为靶标开发治疗肥胖及其相关疾病提供新的药物开发靶点。