【作者】 卢伟；

【导师】 赵水平；

【作者基本信息】 中南大学 ， 内科学， 2006， 博士

【摘要】 背景：载脂蛋白C3(ApoC3)是富含甘油三酯(TG)的脂蛋白及高密度脂蛋白(HDL)的主要成分，在调节血浆TG水平中起重要作用，与血浆TG水平呈正相关。ApoC3-482C＞T基因多态性位于ApoC3启动子区胰岛素反应原件附近，它的多态性变化与高TG血症、胰岛素抵抗及冠心病密切相关，但不同的学者研究结果又有差别。迄今为止，国内外尚无有关ApoC3基因变异与脑卒中关系的研究。与ApoC3作用相反，ApoA1与动脉粥样硬化及心血管病呈负相关。ApoA1是HDL的主要组成成分，ApoA1和HDL都是胆固醇逆转运的主要元素。ApoA1-75G＞A与血浆ApoA1和HDL-C水平密切相关，携带者血浆HDL-C和ApoA1水平升高，而Lp(a)水平下降，与心血管疾病呈负相关。但其与脑卒中的相关性研究还少见报道。APOA1／C3／A4／A5基因簇在血脂代谢中的作用以及与动脉粥样硬化性疾病的关系越来越受到重视，该基因簇位于人类的11号染色体长臂。大量的研究表明，过度表达或缺乏这些基因，都会导致血脂水平的改变。这个基因簇的多个基因变异与血脂水平及冠心病密切相关。这个基因簇的单基因变异与血脂及动脉粥样硬化相关性的研究比较多，ApoA5与ApoC3多态性之间相互作用对血脂水平的影响也有一些报道，但ApoA1与ApoC3相互作用与脑卒中的关系还未见报道。目的1、探讨ApoC3-482C＞T基因多态性与脑卒中的关系2、探讨ApoA1-75G＞A基因多态性与脑卒中关系。3、探讨ApoC3-482C＞T与ApoA1-75G＞A相互作用对脑卒中的影响。方法采用病例-对照设计，筛选脑梗死212例(动脉血栓性脑梗死165例和腔隙性脑梗死47例)，脑出血209例，对照组291例(非心脑血管疾病人群)为研究对象。采用聚合酶链式反应-限制性片段长度多态性方法测定ApoC3、ApoA1基因多态性。结果：1、在湖南汉族人群中，ApoC3-482C＞T基因型分布为CC 28％，CT 48％和TT 24％；等位基因C、T的频率分别为52％和48％。2、ApoC3-482C＞T基因型分布在三组有显著性差异(P＜0.05)，脑出血组和脑梗死组的CT、TT基因型频率高于对照组，CC型在对照组和脑梗死组之间有差异；TT型频率分布在三组无差异。3、T携带者的TG水平高于非携带者，HDL-C水平明显低于非携带者，差异有显著性。4、T等位基因对糖尿病患者的TG、ApoA1有影响。在CT型中，非糖尿病患者的ApoA1水平明显高于糖尿病者；在TT型中，糖尿病者的TG明显高于非糖尿病者。5、吸烟与T等位基因相互作用，影响血脂水平。吸姻者中T携带者的HDL-C水平低于非携带者。6、单因素logistic回归显示CT+TT基因型对脑梗死有显著影响而对脑出血影响不显著。(脑梗死：OR=1.478，95％CI1.107-2.150，P=0.038；脑出血：OR=1.082，95％CI0.752-1.557，P=0.18)。7、在湖南汉族人群中，ApoA1基因型分布为GG 58.16％，AG 24.77％和AA 17.07％，等位基因G、A的频率分别为70.54％和29.46％。8、ApoA1-75G＞A三种基因型在脑出血、脑梗死和对照组分布有显著性差异(P＜0.05)；脑出血组和脑梗死组的GG基因型频率高于对照组，AG型、AA型对照组明显高于脑出血和脑梗死组(P＜0.05)。9、A携带者的ApoA1、HDL-C水平高于非携带者，有显著差异(P＜0.05)。10、单因素logistic回归分析显示ApoA1-75G＞A对脑出血有显著影响，但对脑梗死影响无显著性。(脑出血AG+AA基因型OR=0.725，95％CI0.548-1.073，p=0.047；脑梗死：AG+AA基因型OR=0.805，95％CI 0.501-1.151)。11、ApoA1和ApoC3基因型对血脂水平、BMI的相互作用不明显。12、ApoA1和ApoC3基因型相互作用对脑卒中有影响。ApoA1 GG型／ApoC3 TT型脑卒中发生率高于其他基因型(P＜0.05)，其中AA／CC型脑卒中发生率最低。13、AA／CC基因型的糖尿病发生率最低，与其它基因型比较有显著差异(P＜0.05)。在脑卒中家族史中，A携带者明显低于非携带者(P＜0.05)。14、logistic回归进行单变量分析，AA／CC型显示对脑梗死有保护作用，对脑出血无明显保护作用，(脑出血：OR=0.987，95％CI 0.741-1.899，P=0.477；脑梗死：OR=0.205，95％CI 0.101-0.417，P=0.003．)。结论1、在中国湖南汉族人群中ApoC3-482C＞T基因变异T等位基因频率高于欧洲人群。该基因变异在脑出血和脑梗死患者与对照组间有显著性差异。携带者(型)产生不利的临床血脂谱，这种作用在糖尿病和吸烟人群中尤为明显。ApoC3-482T基因型对脑卒中的正相关作用独立于其它危险因素2、在脑卒中与对照组之间ApoA1-75G＞A基因型和基因频率分布有显著性差异。携带者(型)产生有利的临床血脂谱。ApoA1-75G＞A基因型对脑卒中具有负相关作用3、对ApoA1和ApoC3基因多态性对血脂水平、体重指数无明显影响，但ApoA1-75A等位基因的ApoC3-482CC型对脑卒中、糖尿病及脑卒中家族史有保护作用。更多还原

【Abstract】 Background: ApoC3 is a major component of triglyceride (TG)-rich lipoproteins (TRLs) and HDL. ApoC3 and serum TG levels are positively correlated. The rare allele of the polymorphic -482C＞T in the promoter region of the ApoC3 gene has frequently been associated with raised ApoC3 and TG levels and correlated to CAD.A common G-to-A substitution in the promoter area of the ApoA1 gene has been described. The A allele was shown to be associated with higher HDL-cholesterol concentrations and can decreased progression of atherosclerosis and reduced risk of coronary events. It is suggested that ApoA1-75G＞A is candidate protective gene for strokes.The opposing effects of ApoA1 and ApoC3 on triglyceride metabolism are intriguing and clinically relevant. Both the ApoA1 and ApoC3 genes are located in the APOA1-C3-A4 gene cluster. Several polymorphic sites have been identified in this gene cluster, and. have been associated with lipid levels and coronary artery disease. It was not known whether there are interaction between the polymorphic ApoA1-75G＞A and ApoC3-482C＞T.Objective:1、To investigate the correlation between stroke and common genetic variants in ApoC32、To investigate the correlation between stroke and common genetic variants in ApoA1.3、To explore the association of interaction between ApoC3 gene polymorphisms and common genetic variants in ApoA1 on the presence of strokes.Method: This was a case-control study, which enrolled 209 cases with cerebral hemorrhage, 212 cases with cerebral infarction and 291 controls without CHD and CVD. Polymerase chain reaction-restricted fragments length polymorphism was used to determine ApoA1 genotype.Results:1. The ApoC3-482C＞T genotype distribution in the subjects was CC 28%, CT 48% and TT 24%, respectively. Allele frequencies for C and T were 52% and 48%, respectively。2. The ApoC3-482C＞T allele and genotype distribution among three groups showed a significant difference. TT genotype frequencies showed a higher frequency in both cerebral hemorrhage group and cerebral infarction compared to control (P＜0.05).3. The levels of TG among CC、CT and TT genotype tended upward respectively. The levels of HDL-C in CT and TT was lower than that of CC, there were significant differences each other.4. In CT genotype, the levels of ApoA1 of diabetic patients Was lower than that of the nodiabetic patients. In TT, the levels of TG of diabetic patients was higher than that of the nodiabetic patients, and the levels of HDL-C was lower than that of the nodiabetic patients.5. In the smoking people, the levels of HDL-C was lower in carriers than in noncarriers.6. The CT+TT genotype is positively correlated to cerebral infarction but there are no correlated between ApoC3-482C＞T and cerebral hemorrhage, (cerebral hemorrhage: OR=1.082, 95% CI0.752-1.557, P=0.18; cerebral infarction: OR=1.478, 95%CI 1.107-2.150, P=0.038。)7. The ApoA1-75G＞A genotype distribution in subjects was GG 58.16%, AG 24.77% and AA 17.07%, respectively. Allele frequencies for G and A were 70.54% and 29.46%, respectively.8. The ApoA1-75G＞A allele and genotype distribution among stroke and control showed a significant difference. GG genotype frequencies showed a higher frequency in both cerebral hemorrhage group and cerebral infarction compared to control (P＜0.05). AG and AA genotype frequencies showed a higher frequency in control compared to both cerebral hemorrhage group and cerebral infarction (P＜0.05).9. The levels of HDL-C in AA was highter than that of GG. (P＜0.05). The levels of TC, ApoB, LDL-C, LP(a), HDL-C/TC were no significant differences between AA genotype and GG genotype.10. The AA+AG genotype had an independent effect on cerebral hemorrhage (OR=0.725, 95% CI0.548-1.073, p=0.047); but there are no significant protectively effect, on cerebral infarction (OR=0.805, 95%CI0.501-1.151。)11. The interaction between the polymorphic ApoA1-75G＞A and ApoC3-482C＞T had not significant effect on the levels of lipid and MBI.12. In the patients with stroke, GG/TT and GG/CT genotype distribution frequency was significant higher than frequencies of AA/CC genotype. In the individuals with stroke family history, A carriers was significant lower than nocarriers (P＜0.05). The AA/CC genotype carriers had a lowest frequency of diabetic than other genotype.13. The AA/CC genotype had a protective effect on cerebral infarction (OR=0.205, 95%CI0.101-0.417, P=0.003), but had no protective effect on cerebral hemorrhage (OR=0.987, 95%CI0.741-1.899, P=0.477).Conclusion:1、This is the first observation of common genetic variants distribution of ApoC3 in Chinese people. The T allele frequency showed a higher frequency in Chinese compared in Europeans. There were significant differences in ApoC3-482C＞T genotype amorig three groups. The carriers results in a unfavourable of blood lipids, exceptionally in the smoking people and diabetic patients. The CT、TT genotype had an independent unfavourable effect on strokes.2、There were significant differences in ApoA1-75G＞A genotype among three groups. The carriers results in a beneficial profile of blood lipids, The AA+AG genotype had an independent protective effect on strokes.3、The result exhibited an interaction of two genes on stroke. The AA/CC genotype had an protective effect on the individuals with stroke family history, diabetic, and had an protective effect on cerebral infarction.更多还原