【作者】 李柯；

【导师】 欧阳静萍；

【作者基本信息】 武汉大学 ， 病理学与病理生理学， 2010， 博士

【摘要】 目的：动脉硬化和左心室肥厚是原发性高血压及其心血管并发症的发生发展因素,也是原发性高血压的主要病理表现之一。临床流行病学研究显示炎症因子与动脉硬化的发生密切相关,但炎症因子基因多态性在动脉硬化发生中的作用尚不完全清楚。本研究以美国青少年人群作为研究对象,分析炎症标志物白介素6、白介素6受体、C反应蛋白和粘附分子基因的单核苷酸多态性在美国青少年人群中的分布特点,以及与应激介导的血压升高之间的相关性、与动脉僵硬程度的相关性,试图从遗传学角度分析炎症在动脉硬化发生发展中的作用。方法：从美国乔治亚州奥古斯塔(Augusta)市招募青少年受试者,进行标准化的问卷调查和体格检查。提取外周血白细胞基因组DNA,应用聚合酶链反应法和Taqman探针法,检测研究对象炎症标志物白介素6、白介素6受体、C反应蛋白和粘附分子的基因单核苷酸多态性位点。受试者完成3次应激实验(5分钟心算、3分钟的游戏竞赛和3分钟的前额冷应激),在实验前和实验后测量血压、动脉硬化程度和左心室几何结构指标。运用SPSS15.0统计学软件分析炎症因子和粘附分子等位基因分布特点及其单核苷酸多态性与血压、动脉僵硬程度和左心室几何结构等指标的相关性。结果：本研究招募的美国南部健康青少年受试者中,非洲裔美国人的基础收缩压高于欧洲裔美国人(114.0±10.9 vs.110.2±10.0 mmHg, p＜0.0001),部分已达到临界高血压水平(>120mmHg,<140mmHg).非洲裔美国人颈-桡动脉PWV高于欧洲裔美国人(6.7±1.0 vs.6.3±1.1, p<0.0001),非洲裔美国人总外周阻力指数高于欧洲裔美国人(28.6±8.4 vs.26.1±1.6, p＜0.0001).非洲裔美国人左心室室壁厚度各指标均高于欧洲裔美国人,收缩期左心室内径和心指数低于欧洲裔美国人。在美国南部健康青少年受试者中,男性的基础收缩压高于女性(115.3±10.4 vs.108.9±9.8mmHg, p＜0.0001),部分已达到临界高血压水平(>120mmHg,<140mmHg)。男性应激收缩压增加的幅度高于女性(126.5±12.1 vs.115.8±0.8 mmHg, p<0.0001),应激总外周阻力指数高于女性(31.7士8.4 vs.29.6士7.8,p<0.0001),但应激心脏指数和应激心率却低于女性。男性左心室室壁厚度各指标均高于女性。在美国南部健康青少年受试者中,C反应蛋白基因多态性G1059C与应激舒张压、△心率、左心室重量指数和室间隔舒张末期厚度存在相关性。C等位基因携带者与G等位基因携带者相比,应激时舒张压低、心率增高的程度低、舒张期室间隔厚度高、左心室质量指数高。C反应蛋白基因-717A>G多态性,A等位基因携带者,基础脉压、颈-足背动脉PWV和颈-桡动脉PWV均低于G等位基因携带者。C反应蛋白基因-286C>T>A多态性与动脉僵硬度、左心室肥大密切相关。白介素6基因G-174C多态性,CC基因型携带者颈-桡动脉PWV低于CG、GG基因型携带者。gp130基因rs3729961多态性,CC基因型携带者与CG、GG基因型携带者相比,总外周阻力高。IL6R基因D358A多态性和rs4072391均与基础脉压相关。IL6R基因单体型CCT(212)携带者基础心脏指数高于CTT(222)单体型携带者,而基础TPX、LVMI、LVPWD、IVSD、IVSS、RWT低于CTT(222)单体型携带者。在美国南部健康青少年受试者中,P选择素单核苷酸多态性290Asn等位基因的携带者颈-桡动脉PWV和颈-足背动脉PWV均增高。同时,首次发现P选择素单核苷酸多态性rs2244529与颈-足背动脉PWV。细胞间粘附分子-1基因Gly241Arg单核苷酸多态性的Arg241Arg和Gly241Arg基因型携带者的颈-足背动脉PWV低于Gly241Gly基因型的携带者。血管粘附分子-1基因Asp693Asp单核苷酸多态性的CC基因型携带者的颈-足背动脉PWV高于CT和TT基因型携带者。P选择素基因单核苷酸多态性Ser290Asn、细胞间粘附分子-1基因单核苷酸多态性Gly241Arg和血管粘附分子-1基因多态性Asp693Asp具有协同效应,在所有能影响颈-足背动脉PWV的因素中起到3.6%的作用。结论：在美国南部健康青少年受试者中,非洲裔美国人的血压水平、肌性动脉僵硬程度在青少年阶段已高于欧洲裔美国人,左心室功能低于欧洲裔美国人,提示遗传因素可以影响动脉僵硬程度,并具有种族差异。在美国南部健康青少年受试者中,男性的血压水平在青少年时期就已经高于女性,左心室功能低于女性,提示雌性激素能减弱动脉僵硬度。在美国南部健康青少年受试者中,C反应蛋白基因多态性G1059C、-717A>G、-286C>T>A多态性与动脉僵硬度和左心室室壁厚度相关。白介素6基因单核苷酸多态性G-174C、gp130基因单核苷酸多态性rs3729961、IL6R基因单核苷酸多态性D358A和rs4072391与动脉僵硬度相关。P选择素单核苷酸多态性Ser290Asn和rs2244529、细胞间粘附分子-1单核苷酸多态性Gly241Arg和血管粘附分子-1单核苷酸多态性Asp693Asp是动脉硬化的易感基因。本研究发现炎症因子和粘附分子基因型能影响动脉硬化的发生发展。分析炎症因子和粘附分子的单核苷酸多态性能帮助确定心血管疾病的危险因素。更多还原

【Abstract】 Aim:Arterial stiffness and left ventricular hypertrophy are the most important cause of essential hypertension and its cardiovascular diseases complication, also the main pathology phenomena of essential hypertension. It was reported that inflammation status correlate with arterial stiffness, but the role of inflammation in the development of arterial stiffness is still unclear. This study analyze the distributions of inflammation markers’single nucleotide polymorphisms (SNPs) in American youth, the correlations between the SNPs with the phenotypes of arterial stiffness and left ventricular structure, to discover the genetic role of inflammation in the onset of arterial stiffness.Methods:A total of 926 normotensive adolescents including whites and blacks (17.6±3.3 yrs,43.4% blacks) were recruited in Augusta area. Participants were subjected to a stress-protocol including three tasks (a 5 minute mental math, competence interview, a 3 minute video game challenge, and a 3 minute cold pressor test). Blood samples were obtained before and after the tasks, and SNPs of interleukin-6, interleukin-6 receptor alpha, C-reactive protein, E-selectin, P-selectin, vascular cell adhesion protein-1, and intercellular Adhesion Molecule-1 were genotyped. The blood pressure and the phenotype of arterial stiffness were measured before and after the tasks, and the left ventricular structure was measured by 2D directed M-mode echocardiograms. The correlations between the genotypes of inflammation markers and phenotypes of arterial stiffness and left ventricular structure were carried out by SPSS15.0.Result: in this study, the African Americans subjects (AA) have higher baseline systolic blood pressure (BP) than European Americans subjects (EA) (114.0±10.9 vs. 10.2±10.0 mmHg, p<0.0001), and the BP of some AA’s reach the criteria of prehypertension (>120mmHg,<140mmHg). AA’s carotid-radial PWV (cr-PWV) were higher than EA’s (6.7±1.0 vs. 6.3±1.1,p<0.0001), total peripheral resistance index (TPX) of AA’s were higher than EA’s (28.6±8.4与26.1±7.6,p<0.0001). The indexes of left ventricular (LV) thickness were higher in AA’s than in EA’s, but the left ventricle internal dimension in systole (LVIDs) and cardiac index (CI) were lower in AA’s than in EA’s.Male subjects have higher baseline systolic BP than female (115.3±10.4 vs.108.9±9.8 mmHg,p<0.0001), and the BP of some males reach the criteria of prehypertension (>120mmHg,<140mmHg). Male subjects have higher stress systolic BP (126.5±12.1 vs. 115.8±0.8 mmHg,p<0.0001), and higher stress TPX (31.7±8.4 vs.29.6±7.8,p<0.0001) than female, but stress CI and stress high rate lower than female. Male have higher indexes of left ventricular (LV) thickness than female.For C-reactive protein (CRP), The C allele carriers of G1059C have lower diastolic BP, lower△HR, and higher interventricular septum thickness in diastole (IVSd), higher left ventricular mass index (LVMI) than G allele carriers. The A allele carriers of-717A>G have lower baseline pulse pressure (PP), lower carotid-foot PWV, lower carotid-radial PWV than G allele carriers.-286C>T>A was correlated with arterial stiffness and LV structure.For interleukin-6 (IL6), The CC genotype carriers of G-174C have lower carotid-foot PWV than CG/GG carriers.For gp130, the CC genotype carriers of rs3729961 have higher TPX than CG/GG carriers.For IL6 receptor alpha, D358A and rs4072391 were correlated with baseline PP. The CCT(212) haplotype carriers have higher baseline CI, but lower baseline TPX, than LVMI, LVPWD, IVSD, IVSS, RWT than CTT(222) haplotype carriers.For P-selectin, The 290Asn allele carriers of Ser290Asn have higher carotid-foot PWV and carotid-radial PWV than other carriers. The C allele carriers of rs2244529 have lower carotid-foot PWV than TT carriers.For intercellular Adhesion Molecule 1 (ICAM-1), The Arg241Arg and Gly241Arg carriers of Gly241Arg have lower carotid-foot PWV than Gly241Gly carriers.For vascular cell adhesion protein-1 (VCAM-1), The CC genotype carriers of Asp693Asp have higher carotid-foot PWV than CT and TT carriers.The synergetic effects of Ser290Asn (SELP), Gly241Arg (ICAMl) and Asp693Asp (VCAM1) could explain a greater portion (3.6%) of the foot PWV than any single SNPs. Conclusion:In American youth, AA subjects have higher BP level and arterial stiffness, and lower LV function, compare to the EA subjects, which could be explained by the genetic effect in difference Ethnic population.In American youth, male subjects have higher BP level and lower LV function, compare to the female subjects, which could be explained by the genetic effect in gender difference.In American youth, the G1059C,-717A>G,-286C>T>A SNPs of CRP were correlated with arterial stiffness and LV hypertrophy. The G-174C (IL6), rs3729961(gp130), D358A(IL6R), and rs4072391(IL6R) were correlated with arterial stiffness.P-selectin (Ser290Asn and rs2244529), ICAM-1 (Gly241Arg) and VCAM-1 (Asp693Asp) were predisposing genes for arterial stiffness.In conclusion, this study showed that the genetic variations of inflammation markers and adhesion molecules affect the development of arterial stiffness. To explore the SNPs of these molecules may help understand the pathophysiologic process in arterial stiffness.更多还原