人主动脉粥样硬化病变中修饰脂蛋白的研究

目的研究人粥样硬化病变主动脉中丙二醛（ＭＤＡ）和４羟基壬烯醛（ＨＮＥ）修饰载脂蛋白Ｂ（ａｐｏＢ）的分布特点、含量和理化特性,并与脂蛋白（ａ）［Ｌｐ（ａ）］和ａｐｏＢ的分布进行比较。方法应用免疫组织化学、电镜、免疫电镜以及生物化学等方法进行定性或定量分析。结果ＭＤＡ和ＨＮＥ－ａｐｏＢ在细胞外基质中的分布与Ｌｐ（ａ）和ａｐｏＢ一致,但在泡沫细胞内则有不同。ＭＤＡ－ａｐｏＢ和ＨＮＥ－ａｐｏＢ在泡沫细胞内呈环状、孔状分布,与蜡样色素相似。病变动脉内膜低密度脂蛋白的超微结构、化学成分及电泳行为均与体外修饰脂蛋白相似,其醛类修饰ａｐｏＢ含量明显高于无病变者。结论脂蛋白的氧化性修饰是动脉粥样硬化发生的必要条件。     

脂蛋白（a）杂交瘤细胞株的建立及鉴定

用脂蛋白（ａ）［Ｌｎ（ａ）］免疫ＢＡＬＢ／ｃ小鼠，应用淋巴细胞杂交技术，将免疫小鼠的脾细胞与ＮＳ１骨髓瘤细胞进行融合，得到６Ｇ８、９Ｆ１１２株分泌抗Ｌｐ（ａ）单克隆抗体的杂交瘤细胞株，对２株细胞进行免疫学鉴定，应用间接ＥＬＩＳＡ法证明，培养上清效价１×１０－３～２×１０－３，培养上清与Ｌｐ（ａ）呈阳性反应，而与ａｐｏＡⅠ、ＡⅡ、Ｂ、ＣⅢ、Ｅ及血浆纤溶酶原（ＰＬＣ）均无交叉反应，ＥＬＩＳＡ相加实验证明：２株杂交瘤细胞株分别识别Ｌｐ（ａ）分子上２个不同的抗原决定簇。     

氧化修饰引起脂蛋白（a）结构和生化特性变化

本文观察了体外丙二醛（ＭＤＡ），铜离子（Ｃｕ２＋氧化修饰的脂蛋白（ａ）［Ｌｐ（ａ）］结构和生物学性质的变化。氧化修饰Ｌｐ（ａ）过氧化程度增高，负电荷增加，易被巨噬细胞—清道夫受体识别和摄取。ＭＤＡ修饰Ｌｐ（ａ）出现新的ＭＤＡ－ＬＤＬ位点；同纤维蛋白溶酶原（Ｐｇ）竞争抑制试验显示氧化、修饰Ｌｐ（ａ）同Ｐｇ同源性增加。提示载脂蛋白（ａ）状态同动脉粥样硬化的病理过程有关。     

离体培养动脉内皮细胞结合,内移和降解脂蛋白（a）作用的研究

本文研究离体培养动脉内皮细胞通过ＬＤＬ受体结合，内移和降解脂蛋白（ａ）［Ｌｉｐｏｐｒｏ－ｔｅｉｎ（ａ），Ｌｐ（ａ）］的作用，实验取第３－４代离体培养的动脉内皮细胞分为两组，对照组培养液中不加碘标的脂蛋白（ａ）［＾１２５Ｉ－Ｌｐ（ａ）］，实验组培养液中加＾１２５Ｉ－Ｌｐ（ａ）最终浓度分别为０．２５、０．５、１、１０和５０μｇ／ｍｌ。用γ计数器测定内皮细胞对Ｌｐ（ａ）的结合、内移和降解值，并测定内皮细     

脂蛋白（a）的赖氨酸结合异质性对纤溶酶原与血小板结合的影响

将序列超速离心结合凝胶层析分离纯化的Ｌｐ（ａ）进行Ｌ－Ｌｙｓｉｎｅ－Ｓｅｐｈａｒｏｓｅ４Ｂ亲和层析，分离出能与柱结合的Ｌｐ（ａ）Ｌｙｓ和不能与柱结合的Ｌｐ（ａ）Ｌｙｓ；进一步观察了功能异质性的上述两种Ｌｐ（ａ）对纤维溶酶原与血小板结合的影响。结果表明：Ｌｐ（ａ）Ｌｙｓ能有效地抑制纤溶酶原与血小板的结合，其ＩＣ５０约为０．１９ｍｇ／ｍＬ，而Ｌｐ（ａ）Ｌｙｓ则无明显抑制作用。     

冠心病患者血清脂蛋白（a）分析

冠心病患者血清脂蛋白（ａ）分析金争鸣黄元伟（浙江医科大学附属一院心血管研究室，杭州３１０００３）Ｌｐ（ａ）是人血浆中的一种特殊脂蛋白，近年来，它在冠心病发生、发展中的作用已引起广泛关注。本文检测冠心病人及正常人血清Ｌｐ（ａ）水平，并分析与其他血脂成分...     

肾炎和肾病综合征患者血清脂蛋白（a）水平的临床意义

肾炎和肾病综合征患者血清脂蛋白（ａ）水平的临床意义程新宪１赵怡生２易忠群１赵惠芳１杨欣国３（１解放军３２３医院中心实验室，西安７１００５４２西安市中心医院３第四军医大学唐都医院心内科）近年研究证实脂蛋白（ａ）［Ｌｐ（ａ）］是动脉粥样硬化性心脑血管疾...     

肾脏病患者脂蛋白（a）的异常代谢

本文检测和分析了７３例各类肾脏疾病患者和对照组人群的血脂、载脂蛋白、血清和尿液中Ｌｐ（ａ）水平，表明各类肾小球疾病及慢性肾衰、糖尿病肾病患者具脂质代谢异常，血清高浓度脂蛋白为其另一生代特征。血清脂蛋白同血清白蛋白、尿总蛋白及尿蛋白分子大小均显著相关；尿Ｌｐ（ａ）排泄减少，且同血清肌酐水平相关。     

冠心病患者的脂蛋白（a）含量变化

冠心病患者的脂蛋白（ａ）含量变化徐鸿辉，王逸民，高丽玲近年来许多研究表明Ｌｐ（ａ）与动脉粥样硬化的发生密切相关，为了探讨Ｌｐ（ａ）水平与冠心病（ＣＨＤ）的关系，我们对１９９２年１月以来住院的１００例ＣＨＤ患者Ｌｐ（ａ）及血脂，载脂蛋白的检测结果进行了...     

男性冠心病患者性激素与脂蛋白（a）关系的初步探讨

目的：探讨男性冠心病患者性激素与血脂的关系。方法：分别用放射免疫法及ＥＬＩＳＡ法测定血清性激素及脂蛋白（ａ）［Ｌｐ（ａ）］水平，用酶法及透射比浊法测定血胆固醇及载脂蛋白浓度。结果：冠心病组血清睾酮（Ｔ）、高密度脂蛋白胆固醇（ＨＤＬ－Ｃ）明显低于正常对照组（Ｐ＜００１），血清雌二醇与睾酮比率、Ｌｐ（ａ）明显高于正常对照组（Ｐ＜００１），而血清雌二醇（Ｅ２）、载脂蛋白及血浆总胆固醇（ＴＣ）两组间无显著差异（Ｐ＞００５）。冠心病组血清Ｔ水平与ＨＤＬ－Ｃ水平呈显著正相关（Ｐ＜００１），与Ｌｐ（ａ）水平呈显著负相关（Ｐ＜００５）；血清Ｅ２水平与Ｌｐ（ａ）水平无相关性。结论：睾酮下降为主的性激素失衡是男性冠心病的致病因子。     

Detection of lipoprotein(a) in intraparenchymal cerebral vessels: correlation with vascular pathology and clinical history

Serum levels of lipoprotein(a), Lp(a), have been shown to be associated with increased risk of atherosclerosis (AS) and AS-related diseases such as myocardial and ischemic cerebral infarcts (ICI). Lp(a) has been detected in the vascular wall of the aorta and coronary vessels, and we documented the presence of apo(a) in cerebral vessels of the Circle of Willis, associated with AS changes. In this study we further investigated and characterized the biochemical nature of Lp(a) detected in both large and small cerebral parenchymal vessels. Autopsy specimens of cerebral vessels of 51 patients were examined by immunohistochemistry with monoclonal antibodies against apo(a), apoB, and plasminogen. Lp(a) was detected in cerebral capillaries and arterioles. All of the 8 patients with ICI expressed Lp(a) in parenchymal vessels, generally (6/8) in both capillaries and arterioles. Of 43 patients without ICI only 25 had Lp(a) detected. Among the patients without ICI, there was a slightly increased incidence of parenchymal Lp(a) in those patients who had severe hypoxic brain damage (12/20) compared to those patients without severe hypoxic damage (9/23). Thus, the presence of Lp(a) in small cerebral parenchymal vessels may reflect the role of Lp(a) in ICI.     

Lack of association of apolipoprotein E polymorphism with plasma Lp(a) levels in the Chinese

Apolipoprotein E (apoE) polymorphism and its influence on plasma lipids, lipoproteins, lipoprotein (a) [Lp(a)] and apolipoproteins was studied in 536 (270 males and 266 females) healthy Chinese in Singapore. From analysis of variance with age and BMI as covariates, apoE genotype was found to exert a significant influence on plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and apoB in females. Its effect in males was marginally significant only on LDL-C. In both sexes, plasma TC, LDL-C and apoB were lower in those who were E2-3 than in those who were E3-3. There was no significant difference in log-transformed Lp(a) level between the apoE genotypes after adjusting for the confounding effect of LDL-C in addition to age and BMI. The percentage variance (R2times100) of the lipid traits explained by apoE polymorphism in the females was 4.94% for plasma TC, 5.85% for LDL-C and 4.25% for apoB. We conclude that: 1) ε2 allele had a lowering effect on plasma TC, LDL-C and apoB; 2) apoE polymorphism did not have any significant influence on Lp(a) concentration; and 3) the effect of apoE polymorphism on plasma TC, LDL-C and apoB was gender-specific, with a stronger influence in females than in males.     

难治性肾病综合征患儿载脂蛋白E基因多态性的研究

目的：研究难治性肾病综合征（steroid-resistant idiopathic nephrotic syndrome,SRINS)患儿载脂蛋白E基因多态性,为临床上正确选择合适的脂质代谢紊乱病例进行降脂治疗提供依据。方法：用酶法测定了60例SRINS患儿及80例健康儿童血脂、脂蛋白、载脂蛋白3种物质共7个脂质代谢指标,用PCR－SSCP法检测载脂蛋白E（apoE)基因型,并行肾穿刺活检术检查肾病综合征患儿病理类型。结果：SRINS患儿存在明显脂质紊乱,与健康儿童比较差异有显著性（P＜0．01）,随诊半年后仍有绝大多数SRINS患儿存在明显脂质代谢紊乱。难治性肾病综合征apoε2等位基因显著多于健康儿童（P＜0．05）。结论：SRINS患儿脂质代谢紊乱持续的时间较长,这类患儿,尤其携带ε2等位基因者,更易发生进行性肾脏损害,动脉粥样硬化及冠心病。应考虑给这类患儿使用降脂药物。     

Effects of apoE gene polymorphism on Lp(a) concentrations depend on the size of apo(a): a study of 466 white men

 Polymorphisms in the genes for the low-density lipoprotein (LDL) receptor ligands, apolipoprotein E (apoE), and apolipoprotein B (apoB) are associated with variation in plasma levels of LDL cholesterol. Lp(a) lipoprotein(a) [Lp(a)] is LDL in which apoB is attached to a glycoprotein called apolipoprotein(a) [apo(a)]. Apo(a) has several genetically determined isoforms differing in molecular weight, which are inversely correlated with Lp(a) concentrations in blood. The interaction of apo(a) with triglyceride-rich lipoproteins differs with the size of apo(a), and therefore the effects of apoE gene polymorphism on Lp(a) levels could also depend on apo(a) size. We have investigated the possible effect of genetic variation in the apoE and apoB genes on plasma Lp(a) concentrations in 466 white men with different apo(a) phenotypes. Overall there was no significant association between the common apoE polymorphism and Lp(a), but in the subgroup with apo(a)-S4, concentrations of Lp(a) differed significantly among the apoE genotypes (P=0.05). Lp(a) was highest in the apoE genotypes ɛ₂ɛ₃ and ɛ₃ɛ₃ and lowest in genotype ɛ₃ɛ₄, and the apoE polymorphism was estimated to account for about 2.4% of the variation in Lp(a). In contrast, in the subgroup with apo(a)-S2 Lp(a) was significantly lower (P=0.04) in apoE genotype ɛ₂ɛ₃ than in genotype ɛ₃ɛ₃. Lp(a) concentrations did not differ among the XbaI (P=0.65) or SP 24/27 (P=0.26) polymorphisms of the apoB gene. The expected effects of both apoE and apoB polymorphism on LDL levels were significant in the whole population sample and in subjects with large-sized apo(a) isoforms (P<0.01), whereas no effect was seen in those with low molecular weight apo(a) isoforms. We conclude that the influence of apoE genotypes on Lp(a) concentrations depends on the size of the apo(a) molecule in Lp(a), possibly because both apo(a)-S4 and apoE4 have high affinity for triglyceride-rich lipoproteins and may be taken up and degraded rapidly by remnant receptors. Received: 12 January 1995 / Accepted: 12 July 1996     

Xbal polymorphism in DNA at the apolipoprotein B locus is associated with myocardial infarction (MI)

Bøhn M, Bakken A, Erikssen J, Berg K. Xbal polymorphism in DNA at the apolipoprotein B locus is associated with myocardial infarction (MI). Clin Genet 1993: 44: 241–248. © Munksgaard, 1993 High levels of low density lipoprotein (LDL) and its apolipoprotein B (apoB) are risk factors for atherosclerosis and myocardial infarction (MI). There is rich genetic polymorphism in apoB, first detected as the Ag allotypes of LDL, but today mostly examined at the DNA level. Genes contribute to the population variation in LDL and apoB levels and alleles in polymorphisms at the apoB locus are candidate genes with respect to control of lipid levels and susceptibility to atherosclerosis and MI. The Xbal polymorphism at the apoB locus, which involves the third base of threonin codon 2488 (ACC→ACT) without changing the amino acid sequence was examined in a case-control study comprising 238 survivors of myocardial infarction (MI) and 621 controls. In univariate analysis, frequencies of genotypes in this polymorphism were not statistically different between patients and controls of either sex. However, in multivariate logistic regression analysis, the odds ratio X - X - homozygotes (homozygotes for absence of restriction site) for having MI compared to the pooled group of heterozygotes and X + X + homozygotes (homozygotes for presence of restriction site) was 2.16 (p = 0.007), after adjustments for age, sex, and levels of apoB, high density lipoprotein (HDL) cholesterol (HDLC) and Lp(a) lipoprotein. It appeared that heterozygotes do not have increased risk, compared to the X + X + homozygotes. Stratification according to low or high levels of apoB, HDLC and Lp(a) lipoprotein, showed that the X - X - genotype was more common in patients than controls, in all subgroups. We conclude that the X - allele in double (but not in single) dose most probably increases the risk of MI. The increased risk is apparently not conferred by higher levels of total cholesterol, LDL or apoB, but through some variable or mechanism not closely related to traditional risk factors.     

Vascular accumulation of Lp(a): in vivo analysis of the role of lysine-binding sites using recombinant adenovirus

Despite the importance of lipoprotein(a) [Lp(a)] as an atherogenic risk factor, very little information, especially from in vivo studies, is available concerning which structural features of apo(a) contribute to the interactions of Lp(a) with the vessel wall and its proatherogenic properties. Nearly all the proposed and proven activities of apolipoprotein(a) [apo(a)] focus on its high degree of sequence homology with plasminogen and the possibility that structural features shared by these two molecules contribute to the atherogenesis associated with high Lp(a) plasma levels in humans. In these studies, we examined the properties of three forms of Lp(a) differing at postulated lysine-binding domains contained in the constituent apo(a). We used the recombinant adenoviral gene delivery system to produce apo(a) in the plasma of human apoB transgenic mice, resulting in high levels of Lp(a) similar to those found in the plasma of humans. By comparison of in vitro lysine-binding properties of these forms of Lp(a) with measurements of Lp(a) vascular accumulation in the mice, we have demonstrated that lysine-binding defective forms of Lp(a) have a diminished capacity for vascular accumulation in vivo.     

藏族人载脂蛋白B基因信号肽多态性与血脂水平

目的：了解正常藏族人群载脂蛋白Ｂ（ａｐｏＢ） 基因多态性及其血脂特点。方法：随机选取１００ 例正常成年藏族受试者,男女各半,年龄１８ ～６０ 岁。测定其血清甘油三脂（ＴＧ） 、总胆固醇（ＴＣ） 、低密度脂蛋白胆固醇（ＬＤＬ－ Ｃ） 、高密度脂蛋白胆固醇（ ＨＤＬ－ Ｃ） 、ａｐｏＡＩ、ａｐｏＢ 和脂蛋白（ａ）［Ｌｐ（ａ）］ 的浓度;并采用ＰＣＲ 方法检测其ａｐｏＢ 基因信号肽插入／缺失（ｉｎｓ／ｄｅｌ） ＤＮＡ 片段的多态性,计算各等位基因的分布频率。结果：藏族人群中以ｉｎｓ 等位基因分布为主（０－７４５） ,ｄｅｌ等位基因频率占０－２５５ ,两种等位基因分布无明显的性别差异。组成的三种基因型分别为ｉｎｓ／ｉｎｓ ５６ 例、ｉｎｓ／ｄｅｌ ３７ 例、ｄｅｌ／ｄｅｌ ７ 例。与汉族人群比较,藏族ｉｎｓ／ｄｅｌ 等位基因的频率与其相近,但ｄｅｌ 等位基因频率显著低于西方高加索人种（０－３４０ ,Ｐ＜ ０－０５） 。藏族人群中男女各年龄段（１８ ～３９ 岁、４０ ～６０ 岁） 的各项血脂指标变化不大,但ＴＣ、ＬＤＬ－ Ｃ 和ａｐｏＢ的含量显著低于汉族和西方人群,Ｌｐ（ａ） 的水平与后者接近。ｄｅｌ 等位基因的个体其ＬＤＬ－ Ｃ 的浓度高于ｉｎｓ 者,特别是     

Inherited quantitative DNA variation in the LPA ("apolipoprotein (a)") gene

The Lp(a) antigen resides in a polypeptide chain that is attached to apolipoprotein B (apoB) by a disulfide bridge. Recently, cDNA for this polypeptide chain (frequently referred to as the Lp(a) polypeptide chain, Lp(a) apolipoprotein or apolipoprotein (a] was cloned and extensive homology to plasminogen was uncovered. This homology creates significant difficulties in studying DNA variation in the gene (the LPA gene) for this polypeptide and the plasminogen gene. We have studied a variant 2 kilobase (kb) DNA fragment detectable after digestion with the restriction enzyme MspI, which appears to originate from the LPA gene since it is detected by LPA probes but not with plasminogen probes. It is related to the "kringle IV" region of the LPA gene since it is detected with an LPA probe that only contains "kringle IV" repeats. A proportion of people appears to lack (or have an undetectable level of) the 2 kb fragment and there are significant quantitative differences between samples from people who have the fragment. Presence and amount of this fragment appear to segregate in families as a Mendelian trait. This quantitative DNA variation is likely to reflect differences between individuals in number of "kringle IV" repeats at the LPA locus.     

Quantitation of apolipoprotein B in aortas of hypercholesterolemic swine

An electroimmunoassay has been developed to quantify apolipoprotein B (apoB) in samples of aorta from normolipemic and hypercholesterolemic (diet-induced) swine. Acceptability of the assay was demonstrated using tests for specificity, sensitivity, accuracy, and validity. Specific sites in the grossly normal aortic arch of hypercholesterolemic animals were macroscopically demarcated after the injection of the dye, Evans blue. These blue sites, previously shown to be regions of early lesion formation, contained significantly greater amounts of apoB than adjacent nonblue (white) zones. By contrast, in normolipemic swine no difference in apoB content was found between blue and white regions of the arch. Likewise, the apoB content did not differ among various white regions of grossly normal aortas of hypercholesterolemic swine when no lesions were present. Also, once gross lesions were found in white regions, the apoB content was at least as great as in blue regions. The differences in apoB content between lesioned and nonlesioned areas were greatest in the abdominal aorta. The results of this study are consistent with an enhanced interstitial accumulation of lipoproteins containing apoB, especially low-density lipoprotein, occurring prior to lesion formation in this experimental model.