长链非编码RNA在游离脂肪酸诱导的肝脏胰岛素抵抗中的作用及机制研究

Insulin resistance (IR) is a common risk factor for many metabolic diseases, often exists in the early stage of these diseases, thus improving IR becomes the key for prevention and treatment of many metabolic diseases. The pathogenesis of insulin resistance is complex, there is evidence that free fatty acids (fatty acid free, FFA) is an important cause of IR, but its mechanism is still unclear. Long non-coding RNA (lncRNA) is closely related to the occurrence and development of a variety of complex diseases. However, little research on the relationship between lncRNA and IR has been reported, especially the study about lncRNA in the FFA-induced IR has not been reported so far. Liver is a major target organ of insulin action, our previous experiments found that lncRNA profile showed differential expression in hepatic IR, so we speculated that lncRNA might be involved in FFA-induced hepatic IR. Then, which lncRNA involve in the process of FFA-induced hepatic IR? What are their targets regulated by these lncRNA? By what mechanism do the targets regulated by lncRNA participate in regulation of FFA-induced hepatic IR? Whether the interventions for changed lncRNA can improve FFA-induced hepatic IR? Based on these questions, we will study systematically effects and mechanisms of lncRNA and their targets on FFA-induced hepatic IR. Finally, with lncRNA as potential target, improving hepatic IR, providing new therapeutic strategy to early prevention and treatment of IR related metabolic diseases.

胰岛素抵抗（IR）是多种代谢性疾病的共同危险因素，常存在于疾病的早期阶段，因此改善IR成为防治众多代谢性疾病的关键。IR发生机制复杂，有证据表明游离脂肪酸（FFA）是导致IR的重要原因，然而机制尚不明确。长链非编码RNA（lncRNA）与多种复杂疾病的进展密切相关，然而其与IR关系的研究甚少，尤其是在FFA诱导IR中的研究至今仍没有报道。肝脏是IR发生的重要器官，我们在前期实验中发现，lncRNA在肝脏IR时呈现差异性表达，故推测lncRNA可能介导了FFA诱导的肝脏IR。那么lncRNA是通过何靶点参与此过程的？lncRNA及其靶点又是通过何种机制介导FFA诱导的肝脏IR的？若对这些lncRNA进行干预是否能够改善IR？针对以上问题，我们将全面系统的研究lncRNA及其靶点在FFA诱导肝脏IR中的作用及其机制。最终以lncRNA作为靶点，改善肝脏IR，提出IR相关代谢性疾病的新防控策略。

胰岛素抵抗（IR）是多种代谢性疾病的共同危险因素，如2型糖尿病和非酒精性脂肪肝病（NAFLD）等，常存在于这些疾病的早期阶段，因此，改善IR、调控糖脂代谢紊乱，是防治众多代谢性疾病的关键。IR发生机制复杂，有证据表明游离脂肪酸（FFA）是导致IR的重要原因，然而机制尚不明确。长链非编码RNA（lncRNA）与多种复杂疾病的进展关系密切，但其在FFA诱导的IR中研究甚少。肝脏是IR发生的重要器官，因此本项目通过体内及体外实验，全面系统的研究了lncRNA及其靶点在FFA诱导的肝脏IR中的作用及相关机制。主要完成了以下方面的工作：1. 明确了FFA诱导的肝脏IR时lncRNA表达谱的变化。应用长期高脂饮食喂养小鼠构建FFA诱导肝脏IR的动物模型，通过高通量测序技术，检测出肝脏发生IR时具有差异表达的lncRNA共232个，其中上调的lncRNA有108个，下调的lncRNA有124个。通过生物信息学深入分析，发现这些差异表达的lncRNA其功能及通路类别与IR和糖脂代谢密切相关。2. 经过q-PCR及体外实验验证，我们发现并鉴定了一个在肝脏糖脂代谢过程中发挥重要作用的lncRNA Gm12664-001（ENSMUST00000118306），其在高脂饮食喂养小鼠肝脏组织中及FFA处理的肝细胞中高度表达。机制研究发现lncRNA Gm12664-001通过负调节miR-295-5p表达，致使CAV1表达升高，导致肝脏脂质代谢紊乱和脂质堆积。lncRNA Gm12664-001/miR-295-5p/CAV1可作为一个新的调控机制，为与肝脏IR及脂质代谢紊乱相关的疾病（如NAFLD）的早期防治提供新思路。上述研究结果为揭示lncRNA及其靶点在FFA诱导的肝脏IR中的作用机制提供了新的理论依据，并以此为基础，最终以lncRNA作为靶点，提出与肝脏IR及糖脂代谢紊乱相关疾病的新防控策略。