microRNA-122/33调控SREBP-1c介导的草鱼脂代谢的作用及机理研究

养殖鱼类普遍存在由于脂肪过度蓄积而导致的肝脂质代谢紊乱问题。研究发现microRNAs参与了陆上动物脂代谢过程，但其在鱼类中的作用并不清楚。我们在前期研究中发现，草鱼miR-122/33与肝脂代谢关系密切，且在SREBP-1c 3’UTR区有潜在结合位点。在此基础上，本项目拟以成功建立的草鱼脂变肝细胞及活体模型为材料，通过构建miR-122/33超表达和干扰载体，采用Western blot、qRT-PCR及酶活性测定等技术手段，检测miR-122/33对脂代谢生化指标、关键基因表达及酶活性等的影响，研究miR-122/33在肝脂代谢中的功能；采用荧光素酶报告基因系统检测miR-122/33和SREBP-1c 3’UTR的靶标关系，以期阐释miR-122/33调控SREBP-1c介导的草鱼脂代谢的分子机制。研究结果可为提高草鱼脂肪利用能力和预防脂肪肝等代谢综合症的发生提供新的科学依据。

Lipid metabolism disorders are frequently found often occurred in the fishes feeding with nutritionally -imbalanced diets. Many studies have shown microRNAs play very important roles in lipid metabolism in mammal, but much is unknown in fish. Our previous studies showed miR-122/23 involve in lipid metabolism in grass carp, several potential binding sites are found in 3’UTR of SREBP-1c. In this grant request, grass carp steatosis hepatocyte and in vivo model will be applied, overexpress and knockdown of miR-122/33 will be achieved by overexpression and interference vectors. Biochemical parameters, key genes’ expressions and enzyme activities of lipid metabolism will be determined by western blot, qRT-PCR and enzyme activity measurement; luciferase reporter system will be used to validate the potential binding sites of miR-122/33 in 3’UTR of SREBP-1c. Based on this, we will explore the role and molecular mechanism of miR-122/33 mediated by SREBP-1c in lipid metabolism in grass carp, and this will provide some key scientific directions for the prevention of fatty liver and other metabolic syndrome and for healthy growth of fish.