脂滴是一种单层磷脂膜包裹中性脂，表面分布多种蛋白的多功能细胞器。细胞中大小脂滴数量的“失衡”，可能是诱发代谢疾病的主要原因。miRNA，约22个核苷酸的非编码小分子RNA，在细胞内的定位呈多样性。miRNA调控的异常，往往与代谢性疾病的发生相关。本项目将就脂滴在miRNA的贮存及装配过程中的作用开展研究。我们将纯化大小不同的脂滴，检测（目标）miRNA表达（谱），确定大小不同脂滴上的miRNA结合蛋白。以人工脂滴为工具，构建miRNA结合蛋白突变体以改变miRNA结合脂滴的能力，分析脂滴对miRNA结合及活性的影响，进一步探索miRNA及其复合物在脂滴上的存在形式，并由此确定脂滴在miRNA贮存或是装配中的作用。前期已建立大小脂滴分离方法、构建了人工脂滴。在肝细胞脂滴上发现了多种miRNA及miRNA结合蛋白AGO2，而AGO2在大小脂滴上定位不同。这为我们将要进行的研究奠定了坚实的基础。

Lipid droplet (LD) is a subcellular multi-functional organelle. LDs are surrounded by a protein-coated phospholipid monolayer with a hydrophobic neutral lipid core, and confer many important roles in multiple biological processes. An imbalance between large and small LDs may be a central event in the development of metabolic syndrome. microRNAs (miRNAs) , a class of small noncoding RNAs, typically 22 nucleotides in length, are distributed in distinct intracellular locations. Dysregulation of miRNAs can lead to a multitude of metabolic disorders. Here we will focus on the lipid droplet-involved miRNA storage (transport) and loading. We will commence study from the lipid droplet subpopulations by size as an entry point. The miRNA expressions on the purified LD subpopulations will be determined. Meanwhile, the miRNA-binding proteins on lipid droplet will be identified. Artificial lipid droplets will be used to learn how LDs will influence miRNA. And we will modify miRNA binding to lipid droplets by mutated the miRNA-binding proteins and study how the function of miRNA will be influenced. Further, how the miRNA and its complex are assembled on lipid droplets and how the miRNA is loading will be studied to find out the role of LD in miRNA storage or loading. To date, we have set up the way to separate lipid droplets by size as well as the artifical lipid droplet system. Various miRNAs have been identified on hepatic lipid droplet. The miRNA-binding protein AGO2 has been found to locate on isolated lipid droplets and it exhibited different locations on distinct LD subpopulations.