Effects of mutant apolipoprotein A-I on the reverse cholesterol transport

突变型载脂蛋白A-I对胆固醇反向转运的影响

• 批准号: 08671196
• 负责人: MATSUNAGA Akira
• 金额: $ 0.9万
• 依托单位: Fukuoka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08671196/
• 关键词: apolipoprotein A-I; apo A-I; mutation; fractional catabolic rate; recombinant; expression; cholestrol efflux; アポリポ蛋白; 遺伝子; 変異体

It is widely assumed that high density lipoproteins (HDL) exert their antiatherogenic role by contributing to the reverse transport of excess cholesterol from peripheral cells to the liver and steoidogenic organs. In complexes with HDL,apolipoprotein (apo) A-I acts as the most potent activator of the plasma enzume lecithin : chlesterol acyltransferase (LCAT) and increases cholesterol efflux from peripheral tissues. In our laboratory, ten different apo A-I mutations were characterized. In this project, functional consequences of the mutation were examined by expressing the mutated and wild-type recombinant proapo (r-proapo) A-I cDNAs in E.coli. We produced four different mutations of r-proapo A-I,proapo A-I (Tyr100His) Karatsu, proapo A-I (Trp108Arg) Tsushima, proapo A-I (Vall56Glu) Oita, proapo A-I (Glu235*0) Nichinan Cholesterol efflux to r-proapo A-I (Glu235*0) Nichinan from mouse peritoneal macrophages converted with [^3H] cholesterol-labeled acetylated LDL was decreased by 54% when compared that of normal r-proapo A-I.In vivo turnover studies in normal rabbits demonstrated that the r-proapo A-I Nichinan was rapidly cleared by 22% compared with normal r-proapo A-I.We conclude that the apo A-I (Glu235*0) Nichinan induced a critical structural change of the carboxyl-terminal domain of apo A-I for cellular cholesterol efflux and increased catabolism of the apo A-I,resulting in low HDL cholesterol level. We are going to continue the next experiment for functional analysis of mutant apo A-I.

人们普遍认为高密度脂蛋白(高密度脂蛋白)通过将多余的胆固醇从外周细胞反向转运到肝脏和类脂生成器官来发挥其抗动脉粥样硬化的作用。在与高密度脂蛋白的复合体中，载脂蛋白(Apo)A-I是血浆卵磷脂：胆固醇酰基转移酶(LCAT)最有效的激活剂，并增加外周组织的胆固醇流出。在我们的实验室中，我们鉴定了10种不同的载脂蛋白A-I突变。在本项目中，通过在大肠杆菌中表达突变的和野生型的重组proapo(r-proapo)A-I cDNA来检测突变的功能后果。我们产生了四种不同的r-proapo A-I，proapo A-I(Tyr100His)Karatsu，proapo A-I(Trp108 Arg)Tsushima，proapo A-I(Vall56Glu)Oita，小鼠腹腔巨噬细胞经[~3H]胆固醇标记的乙酰化低密度脂蛋白转化后，原载脂蛋白A-I(Glu235*0)尼希南胆固醇外流到r-原载脂蛋白A-I(Glu235*0)，与正常r-原载脂蛋白A-I相比，降低了54%。在正常兔体内的周转研究表明，与正常r-原载脂蛋白A-I相比，r-原载脂蛋白A-I尼希南能迅速清除22%。细胞胆固醇外流和载脂蛋白A-I分解代谢增加，导致低高密度脂蛋白胆固醇水平。我们将继续下一步的实验，对突变的载脂蛋白A-I进行功能分析。

项目成果

Matsunaga A: "A cystein containing truncated apolipoprotein A-I associated with high density lipoprotein deficiency" Arterioscler Thromb Vasc Biol. 16. 1416-1423 (1996)

Matsunaga A：“含有与高密度脂蛋白缺乏症相关的截短载脂蛋白 A-I 的半胱氨酸”Arterioscler Thromb Vasc Biol。

Wei Huang, et al.: "A Novel Homozygous Missense Mutation in Apo A-I Gene with Apo A-I Deficiency" Artherioscler Thromb Vasc Biol. 18. 389-396 (1998)

Wei Huang, et al.：“Apo A-I 基因中的新型纯合错义突变，伴有 Apo A-I 缺陷” 动脉粥样硬化血栓 Vasc Biol。