slincRAD在脂肪细胞分化中的调控作用和机制

Abnormal adipogenesis and lipid genesis are common pathological bases of obesity, diabetes and cardiovascular diseases. Long non-coding RNA (lincRNA) is a abundant class of cellular transcripts, which play an essential role in cell proliferation and differentiation. However, the roles and function mechanisms of lincRNA in adipogenesis are largely unknown. Our previous study identified a adipogenesis-associated lincRNA named slincRAD. More recently, by introducing slincRAD-targeting shRNAs into 3T3-L1 preadipocyte and mouse zygotes, we established slincRAD-repression cell strains and transgenic mouse models. We found that knockdown of slincRAD expression not only interfere with 3T3-L1 adipogenesis, but also severely compromised the normal development of the adipose tissue and the mice. In the present application, we plan to investigate the molecular mechanisms of slincRAD in adipogenesis. We will systematically identify the downstream target genes of slincRAD, characterize slincRAD-interacting molecules, so as to resolve the regulatory network and the function mechanism of slincRAD. The present study may also provide diagnosis and therapeutic targets for adipogenesis-related diseases.

脂肪细胞分化和脂质生成异常是肥胖、糖尿病及心脑血管疾病一个共同的病理基础。长非编码RNA是一类在高等生物中广泛存在的基因转录本，对细胞增值分化等生命活动具有重要的作用，但目前对长非编码RNA在脂肪细胞分化中的功能和作用机制的了解还非常少。前期研究中，我们鉴定了一个与脂肪细胞分化相关的长非编码RNA基因slincRAD；通过建立slincRAD低表达3T3-L1细胞株和转基因小鼠模型，我们发现slincRAD不仅控制3T3-L1细胞的分化过程，还对小鼠脂肪组织的形成及个体发育发挥了调控作用。在本申请项目中，我们将深入研究slincRAD调控脂肪细胞分化的分子机制，拟系统鉴定受slincRAD调节的下游信号通路及靶基因，并将通过筛查与slincRAD相互作用的蛋白因子（尤其是表观调控因子），解析其调控下游信号通路的分子机制。本项目研究获得的结果可为相关疾病的诊断和治疗提供新的分子靶点。

利用分子生物学和细胞生物学的研究手段，本课题在前期工作的基础上鉴定了一条在脂肪细胞分化的早期阶段发挥重要作用的长非编码RNA基因——slincRAD。我们的研究表明在脂肪细胞分化的早期阶段，slincRAD基因的表达即出现了显著的上调，其表达调控过程甚至早于C/EBP、PPAR等关键的脂肪细胞分化因子。slincRAD转录本主要分布于细胞核内，通过招募DNMT1蛋白，形成了slincRAD/DNMT1复合物，发挥对包括p21在内的下游因子的表观调控，影响基因的表达，并进而影响脂肪细胞的分化过程和细胞脂质的生成。