基于大样本平行人群及动物模型的NAFLD代谢组学研究

The prevalence of non-alcoholic fatty liver disease (NAFLD) is rising sharply around the world, and serious challenging human health. However, there is not an effective method of treatment for NAFLD currently. Diet and lifestyle changing is the only option, but too difficult to implement. It is an urgent need that to develop new treatment methods and specific targets. Using metabolomics investigation for NAFLD metabolic changes may further elucidate the molecular pathogenesis and develop effective treatment or targeted drug screening for NAFLD. Our group had conducted a pilot study and has found that metabolic profiles can be well separated the NAFLD and healthy controls, but it still needs large samples to verify this finding. Therefore, this project intends to solve the following two issues: (1) in the initial population study, using metabolomics methods to screen specific, clinically significant different metabolites of NAFLD, and then veryfy these metabolites in validation population, and using 1HNMR to identify these metabolites’ molecular structure; (2) the use of targeted metabolomics dynamically monitor metabolites in animal NAFLD model regarding NAFLD occurrence and development, then retrieve metabolites in databases, such as KEGG, BioCyc and HMDB, for biological analysis, then test related genes and proteins to determine metabolic pathway of the interest metabolites for NAFLD mechanisms. This project would provide new theoretical and experimental basis for NAFLD targeted treatment and prevention.

非酒精性脂肪肝（NAFLD）患病率在世界范围急剧上升，已重危害人类健康，而目前并未建立有效的治疗方法。减肥与改变生活方式是唯一的选择，但难以实施。因此迫切需要开发新的治疗方法与特异的靶点。利用代谢组学研究NAFLD的代谢改变可深入阐明其分子水平的发病机制，有助于建立有效的治疗方案和筛选靶向药物。本课题组预试验已发现NAFLD的代谢图谱可以很好的分离，但需大样本来验证。本项目拟解决两个问题:（1）在首批人群中，利用代谢组学的方法分筛选出NAFLD特异、有临床意义的差异代谢产物，并用另一验证人群验证，及利用1HNMR鉴定分子结构；（2）结合靶向代谢组学与动物模型进一步研究代谢产物与NAFLD发生、发展的关系，并检索国内外KEGG、BioCyc和HMDB等数据库对代谢产物进行生物解析，测定相关基因与蛋白表达，研究其代谢途径，为NAFLD的机制、防控与靶向治疗提供更新、更可靠的理论与实验依据。

非酒精性脂肪肝（nonalcoholic fatty liver disease, NAFLD）是全球最主要的肝脏疾病，患病率在世界范围急剧上升，可诱发多种代谢紊乱疾病，严重危害人类健康。然而，目前并未建立有效的治疗方法，减肥与改变生活方式是唯一的选择，但难以实施。因此需要研究NAFLD的发病机制，并且寻找新的治疗方法与特异的靶点。本研究首先通过流行病学研究，探究NAFLD疾病的筛查方法，并且选取部分人群分析膳食与肝脏脂肪含量的相关性。通过代谢组学技术，探究NAFLD人群的特异性代谢产物的改变。建立了NAFLD大鼠模型，动态监测血液指标的变化，并且通过体外试验，研究了肝细胞脂肪堆积的分子机制。研究结果提示，WHR和FLI可作为常见的预测NAFLD（正常体重型，超重/肥胖型）指标中最准确的指标；肝脏脂肪含量与高能量、高脂肪和高饱和脂肪酸摄入量有关。代谢组学研究方面，研究发现NAFLD人群与健康对照相比，共有24种差异代谢产物，包括脂肪酸、氨基酸等相关代谢产物；并且分析了瘦弱型、超重型和肥胖型NAFLD患者的游离脂肪酸谱差异，发现肉豆蔻酸（14:0）和棕榈烯酸（16:1）有助于NAFLD的早期诊断；分析正常体重NAFLD患者的代谢组学结果，发现消瘦型NAFLD和肥胖型NAFLD之间代谢谱不同，5种代谢产物（脱氢表雄酮、吲哚基硫酸、癸二酸、花生四烯酸和孕烯醇酮硫酸盐）可用作NAFLD患者的诊断因素。此外，建立了大鼠NAFLD模型，并且通过体外试验证明花生四烯酸能够诱导HepG2细胞发生脂肪堆积，且其细胞内脂肪堆积程度与花生四烯酸浓度呈剂量反应关系。以上研究结果，为进一步了解NAFLD亚型的代谢特征和发病机制提供了线索，为NAFLD的诊断和早期可行的膳食干预措施提供支持。