基于代谢组学与微生物组学的苦荞蛋白降脂机理的研究

发布时间：2019-01-22 09:45

【摘要】：随着人们膳食结构的变化及人口老龄化的加剧,目前高血脂症已成为诱发心脑血管疾病发生的重要因素。研究表明:高脂血症与人们饮食有着密切关系,通过调整人们的食物结构是达到干预高脂血症的有效途径之一。苦荞作为我国特有的食物资源,其中的苦荞蛋白已被证明具有降血脂等多种功效,但目前对其降脂机理的研究还不够完善。本文通过高脂膳食+链脲佐菌素(STZ)注射的方式建立代谢紊乱小鼠模型,研究对苦荞蛋白饮食干预后小鼠的血脂血糖代谢(血浆总甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)、空腹葡萄糖(GLU)和胰岛素(INS))的影响,并结合血浆代谢组学分析技术与肠道微生物组学技术(Illumina二代测序技术)从分子水平探究苦荞蛋白的降脂机理。(1)通过对小鼠血浆的分析发现:实验进行6周后,高脂模型组的小鼠肝指数较对照组有显著增加(68.5%),而苦荞蛋白组的肝指数与高脂模型组相比,下降了 13.2%,脂肪肝现象得到缓解。高脂模型组的TC及LDL-C含量较对照组相比有显著提升,分别为86.1%和80.5%,苦荞蛋白组的TC和LDL-C含量较高脂模型组有显著降低,分别为48.1%和47.7% (P0.05),改善了脂代谢。高脂模型组小鼠出现了显著的糖耐量受损现象,而苦荞蛋白可显著改善糖代谢。同时,血浆中炎症因子(脂多糖(LPS)、白细胞介素-6 (IL-6)、肿瘤坏死因子a (TNF-0a))较高脂模型组均有显著下降(P0.05),表明苦荞蛋白对于由高脂膳食引起的炎症反应有一定的抑制作用。(2)利用UPLC-IT-TOF技术获得小鼠血浆代谢轮廓,并结合HMDB、KEGG、MetPA数据库辅助分析,发现由高脂膳食诱导的小鼠代谢紊乱主要与亚油酸代谢、甘油磷脂代谢、鞘脂类代谢、色氨酸代谢、花生四烯酸代谢、糖代谢6条代谢通路相关,并初步鉴别出其中磷脂酰胆碱、亚油酸、磷脂酸、溶血磷脂酰胆碱、甘油、磷脂酰乙醇胺、葡糖苷酸、鞘磷脂、半乳糖神经酰胺、脑苷脂、葡糖神经酰胺、前列腺素G2共12个潜在的生物标志物。(3)利用高通量测序技术(Illumina二代测序技术)对小鼠粪便样品进行微生物组学研究:Alpha多样性分析(OTU数、Shannon指数、simpson指数、Chaol指数、ACE指数)结果显示,对照组的物种丰富度都要显著高于高脂组和苦荞蛋白组,但苦荞蛋白组的菌群多样性要显著高于高脂组,说明苦荞蛋白能使高脂小鼠体内的菌群多样性显著增加,更接近于对照组。Beta多样性分析(PCoA分析、LEfSe分析)结果显示,三组小鼠粪便样品之间具有显著差距,且苦荞蛋白干预组与对照组的组间差异要小于高脂模型组与对照组之间的差异,表明苦荞蛋白具有抑制高脂膳食造成的肠道菌群紊乱的作用。综上所述,苦荞蛋白可调节高脂膳食引起的小鼠肠道菌群结构失衡,这可能是其干预高脂膳食性血脂血糖代谢紊乱的重要作用途径之一。
[Abstract]:With the change of people's dietary structure and the aggravation of population aging, hyperlipidemia has become an important factor to induce cardiovascular and cerebrovascular diseases. The study shows that hyperlipidemia is closely related to people's diet, and it is one of the effective ways to interfere with hyperlipidemia by adjusting people's food structure. Tartary buckwheat (Tartary buckwheat), as a unique food resource in China, has been proved to have many functions such as lowering blood lipid, but the study on its mechanism is not perfect. A model of hyperlipidemic mice with streptozotocin (STZ) was established by injecting high-fat dietary streptozotocin (STZ) into mice. The blood lipid and blood glucose metabolism (total triglyceride (TG), total cholesterol (TC),) of mice treated with Tartary buckwheat protein diet was studied. Effects of high density lipoprotein (HDL-C), low density lipoprotein (LDL-C), fasting glucose (GLU) and insulin (INS), The mechanism of Tartary buckwheat protein (Tartary buckwheat protein) was studied at molecular level by combining plasma metabolomics analysis technique with intestinal microbiome technique (Illumina second generation sequencing technique). (1) the results showed that: after 6 weeks of experiment, the mechanism of Tartary buckwheat protein was analyzed. The liver index of the hyperlipidemic model group was significantly higher than that of the control group (68.5%), while the liver index of Tartary buckwheat protein group was 13.2g lower than that of the hyperlipidemic model group, and the fatty liver phenomenon was alleviated. The contents of TC and LDL-C in the high-fat model group were significantly higher than those in the control group (86.1% and 80.5%, respectively). The TC and LDL-C contents in the Tartary buckwheat protein group were significantly lower than those in the high-fat model group. It was 48.1% and 47.7% (P0.05), which improved lipid metabolism. Hyperlipidemia model mice showed impaired glucose tolerance, while Tartary buckwheat protein significantly improved glucose metabolism. At the same time, plasma inflammatory factors (lipopolysaccharide (LPS), interleukin-6 (IL-6), tumor necrosis factor a (TNF-0a) were significantly lower than those in the hyperlipidemia model group (P0.05). The results indicated that Tartary buckwheat protein could inhibit the inflammatory reaction induced by high fat diet. (2) the plasma metabolic profile of mice was obtained by UPLC-IT-TOF technique and was analyzed by HMDB,KEGG,MetPA database. It was found that the metabolic disorder induced by high fat diet in mice was mainly related to the metabolism of linoleic acid, glycerol phospholipid, sphingolipid, tryptophan, arachidonic acid and glucose. Phosphatidylcholine, linoleic acid, phosphatidic acid, lysophosphatidylcholine, glycerol, phosphatidylethanolamine, glucuronide, sphingomyelin, galactose ceramide, cerebral glucoside, glucosamine, There are 12 potential biomarkers of prostaglandin G2. (3) microflora of mouse fecal samples was studied by high-throughput sequencing (Illumina second-generation sequencing technique): Alpha diversity analysis (OTU number, Shannon index, simpson index, Chaol index, OTU number, Shannon index, simpson index, Chaol index, OTU number, Shannon index, simpson index, Chaol index). The results of ACE index showed that the species richness of the control group was significantly higher than that of the high-fat group and the Tartary buckwheat protein group, but the microbial diversity of the Tartary buckwheat protein group was significantly higher than that of the high-fat group. The results showed that Tartary buckwheat protein could significantly increase the diversity of bacteria in high-fat mice, and was closer to the control group. The results of Beta diversity analysis (PCoA analysis, LEfSe analysis) showed that there was a significant difference between the fecal samples of the three groups. The difference between the intervention group and the control group of Tartary buckwheat protein was smaller than that between the high-fat model group and the control group, which indicated that Tartary buckwheat protein could inhibit the intestinal flora disorder caused by high-fat diet. To sum up, Tartary buckwheat protein can regulate the imbalance of intestinal flora induced by high-fat diet in mice, which may be one of the important ways to interfere with hyperlipidemic blood glucose metabolism disorder.
【学位授予单位】：上海应用技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R151

【相似文献】