高密度脂蛋白糖基化修饰影响细胞胆固醇外排的分子机制

项目名称： 高密度脂蛋白糖基化修饰影响细胞胆固醇外排的分子机制

项目编号： No.31300639

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 生物科学

项目作者： 郭守东

作者单位： 泰山医学院

项目金额： 22万元

中文摘要： 糖尿病可改变高密度脂蛋白（HDL）糖基化修饰进而影响其对心血管系统的保护作用。申请人前期研究发现：与健康人相比，无论是HDL-C水平较低的I型糖尿病患者还是HDL-C水平略有升高的II型糖尿病患者，他们的HDL对RAW264.7巨噬细胞[H3]-胆固醇外排皆有不同程度的影响；而体外非酶催化HDL所得晚期糖基化终产物（AGEs）则可显著抑制细胞胆固醇外排。申请人认为，HDL糖基化修饰影响细胞胆固醇外排并不局限于AGEs,其寡糖链的修饰特别是唾液酸的修饰对细胞胆固醇外排有重要影响。基于前期样本收集、载脂蛋白分离、寡糖链释放、单糖组成分析等工作，申请人拟采用液相串联质谱、气相质谱、甲基化分析、工具酶等研究手段阐释糖尿病患者与健康人HDL寡糖链差异，并利用特异性糖苷酶去糖基化和非酶促糖基化，探讨HDL何种糖基化修饰显著影响细胞胆固醇外排及其分子机制。期待为锁定HDL糖基化修饰的干预靶点提供依据。

中文关键词： 高密度脂蛋白；糖基化；唾液酸；胆固醇外排；动脉粥样硬化

英文摘要： Diabetes can influence the protective effect of high density lipoprotein (HDL) on cardiovascular system by modifying its glycation. Our unpublished research on 26 plasma samples of diabetic demonstrated that the HDL either from type 1 diabetic with a lower HDL-C or type 2 diabetic with a little higher HDL-C exhibit dramatically different effect on [H3]-labeled cholesterol efflux from RAW 264.7 macrophage, as 15 samples significantly decreased cholesterol efflux, 7 smaples showed no impact, and 4 samples markedly increased [H3]-cholesterol efflux. And in vitro non-enzymatic catalyzed HDL glycation by glucose or fructose, the complex also known as advanced glycation end products (AGEs), notably reduced the [H3]-cholesterol efflux. Therefore, we presume that the effect of HDL glycation on cellular cholesterol efflux is not limited on AGEs, the modification of its oligosaccharides on the two major carriers of carbohydrate,apolipoprotein (apo) and gangliosides (GLS), should have important impact on cellular cholesterol efflux, especially for sialic acid on the non-reducing end of the oligosaccharides. Based on our earlier work on sample collection, HDL subfraction separation, release of the O-linked oligosaccharides, monosaccharide analysis of HDL2 and HDL3, apoA-I and apoA-II preparation by anion exchange chromatogr

英文关键词： HDL；Glycosylation；Sialic acid；Cholesterol efflux；Atherosclerosis