高血压继发左心室肥厚的遗传易感性及肥厚型心肌病的修饰基因研究

【作者】 傅春燕；

【导师】 惠汝太； 周宪梁；

【作者基本信息】 中国协和医科大学 ， 遗传学， 2008， 博士

【摘要】 研究背景高血压左心室肥厚是心血管病发病率和死亡率的独立危险因素，也是脑卒中的独立危险因子。虽然高血压的主要并发症是左心室肥厚，但是左心室肥厚的程度与高血压病史的长短、血压水平及降压后逆转的程度并不呈比例，提示有高血压以外的因素参与。研究表明遗传因素对左心室重量的影响大约占非血压因素的60％。以往研究证实β1-肾上腺素受体（beta（1）-adrenergic receptor，ADRB1）在调节心脏结构方面起重要作用。并且也已经有关联研究证实ADRB1基因多态性位点与高血压，冠心病，心肌梗塞等疾病相关，然而这种关系并未在中国高血压人群中证实。研究目的本研究拟在中国人群中验证ADRB1基因多态性位点Arg389Gly和Gly49Ser与高血压左心室肥厚的关联。对象和方法研究对象为河南信阳高血压基地收集的2417例高血压患者包括1189例高血压伴有左心室继发肥厚患者和1228例高血压不伴有左心室继发肥厚患者。基因分型用聚合酶链式反应（PCR）和限制性长度片段多态性（RFLP）方法。卡方检验初步评估上述多态性位点与左心室继发肥厚之间的关系，并应用多元Logisitic回归方程评价校正了左心室继发肥厚传统危险因素后对其发病的影响。研究结果ADRB1基因多态性位点Arg389Gly与高血压左心室继发肥厚相关联。与携带有Arg389Gly基因型和Gly389Gly基因型的患者相比，携带有Arg389Arg基因型的患者具有显著增高的室间隔厚度（IVS）（分别为10.4±1.5mm vs 9.6±1.5mm，P<0.01或者9.4±1.4mm，P<0.01）、左室后壁厚度（PW）（分别为10.4±2.4mm vs9.6±2.4或者9.7±2.9mm，P<0.01）、左心室重量指数（LVMI） (分别为51．6±13．3g/m^2.7vs 44．6±12．9 g/m^2.7,P<0.01或者43．2±14．4 g/m^2.7，P<0．01)和相对室壁厚度（RWT） （分别为45.0±9．0％vs 42．6±8．1％，P<0．01或者43．2±8．8％，P<0.018）。上述显著相关性独立于心血管其他相关危险因素并且在另一个高血压人群中重复实验加以验证（n=327）。结论ADRB1基因多态性位点Arg389Gly可能是高血压左心室肥厚发生的遗传危险因素。研究背景肥厚型心肌病（hypertrophic cardiomyopathy，HCM）为常染色体显性遗传单基因疾病。HCM患者间临床表型存在明显差异，携带同一突变的不同家系及家系内不同患者的临床表型差异很大，主要表现在心肌肥厚程度、肥厚模式、外显率、发病年龄以及是否会发生心衰和猝死等方面。而HCMI临床表型变异仅用基因突变本身解释是远远不够的，修饰基因和环境因素对于HCMI临床表型也起重要作用。修饰基因的定义是，其突变不会导致HCM的发生，但可以影响疾病的严重程度、预后或转归。以往体内体外研究表明β1-肾上腺素受体（beta（1）-adrenergic receptor，ADRB1）与心肌的肥厚发生有重要作用。β1-肾上腺素受体的选择性抑制剂噻利洛尔可以通过阻断一氧化氮介导的信号通路抑制心肌肥厚和心力衰竭，其机制主要为促进一氧化氮合酶的表达从而提高一氧化氮水平。而至今已有许多国内外研究证明一氧化氮及其合成酶在肥厚型心肌病的发生发展中起重要作用。而我们之前的研究也已经发现ADRB1基因多态性位点Arg389Gly与高血压左心室肥厚相关联，其可能是高血压左心室肥厚发生的遗传危险因素。因此我们选择ADRB1基因作为候选基因，研究其与肥厚型心肌病关系以明确ADRBl基因是否为肥厚型心肌病的修饰基因。研究目的本研究拟探讨ADRB1基因多态性位点Arg389Gly和Gly49Ser与HCM是否关联。对象和方法研究对象为在中国医学科学院阜外心血管病医院就诊的267例无血缘关系的HCM患者，以及从河南信阳高血压基地收集的816例健康对照者。基因分型用聚合酶链式反应（PCR）和限制性长度片段多态性（RFLP）方法。卡方检验初步评估上述多态性与HCM的关系，应用One-Way ANOVA分析不同基因型与肥厚型心肌病患者的临床表型的关联。结果ADRB1基因多态性位点Arg389Gly和Gly49Ser的基因型频率在肥厚型心肌病患者和正常对照组比较无统汁学差异，并且携带Arg389Gly和Gly49Ser不同基因型的肥厚型心肌病患者超声参数、临床表型亦无统计学差异。结论表明ADRB1基因多态性位点Arg389Gly和Gly49Ser与肥厚型心肌病患病风险和临床表型无关。ADRB1基因不是肥厚型心肌病的修饰基因。研究背景高血压左心室肥厚是心血管病发病率和死亡率的独立危险因素，也是脑卒中的独立危险因子。虽然高血压的主要并发症是左心室肥厚，但是左心室肥厚的程度与高血压病史的长短、血压水平及降压后逆转的程度并不呈比例，提示有高血压以外的因素参与。研究表明遗传因素对左心室重量的影响大约占非血压因素的60％。钙调磷酸酶信号通路是参与心肌肥厚发生的最重要的信号通路之一，许多体内体外研究已经证明钙调磷酸酶的激活可以引起心肌肥厚的发生。钙调磷酸酶受多种内源性蛋白包括cGMP-依赖蛋白酶（PKGⅠ）、血红素加氧酶（HO-1）、钙调磷酸酶交互作用蛋白1（MCIP1）以及糖原合成酶（GSK3β）等的调节，同样也有研究已经证实PKGⅠ、HO-1、MCIP以及GSK3β等在心肌肥厚中的作用。我们选择PKGⅠ、HO-1、MCIP1以及GSK3β基因作为候选基因，研究其与高血压左心室继发肥厚的关系。研究目的探讨PKG，基因的rs10995555、rs10822178及rs4542348，HO-1基因的rs2071747、rs17884059、rs17879895和rs9282700多态位点，MCIP1基因的rs8133540，以及GSK3β基因的rs334558、rs2276708和rs3755557多态对高血压继发左心室肥厚表型的影响。对象和方法研究对象为河南信阳高血压基地收集的2696例高血压患者包括1271例高血压伴左心室肥厚患者和1425例高血压不伴有左心室肥厚患者。基因分型用聚合酶链式反应（PCR）和限制性长度片段多态性（RFLP）方法。卡方检验初步评估上述多态性与LVH的关系，并应用多元Logisitic回归方程评价校正了LVH传统危险因素后对其发病的影响。研究结果PKGⅠ基因多态性位点rs10822178（-2712A/T）与高血压左心室肥厚相关联，AA+AT基因型增加高血压左心室肥厚的患病风险1.7倍（OR1.70，95％CI1.18-2.47，p=0．005），而且携带AA+AT基因型的高血压患者室间隔厚度（IVS）（在高血压伴左室肥厚病人中，P<0．01；在高血压不伴左室肥厚患者中P<0．01）和左心室重量指数（LVMI）（在高血压伴左室肥厚患者中，P<0．05；在高血压不伴左室肥厚患者中P<0．01）较携带TT基因型的高血压患者明显增加。其他入选的多态性位点不增加LVH的发病风险。结论PKGⅠ基因多态性位点-2712A/T可能是高血压左心室肥厚发生的遗传危险因素。更多还原

【Abstract】 Background: Left ventricular hypertrophy （LVH） is associated with cardiovascular morbidity and mortality, as well as all-cause mortality. LVH is also independently associated with risk of ischemic stroke. Although hypertension is a major cause of LVH, the degree of LVH does not parallel to the level of blood pressure, the duration of hypertension, or reversal of hypertensive LVH by pharmacological treatments. This implies that other factors may be involved in LVH in addition to blood pressure. It has been reported that genetic factors account for 60% of blood pressure-independent cardiac mass variances. Experimental evidence supports a key role for beta（1）-adrenergic receptor （ADRB1） in the modulation of cardiac mass. This relationship has not yet been described in Chinese population.Objectives: We hypothesized that the polymorphisms of ADRB1 gene might confer higher risk of LVH. We tested whether the variations of ADRB1 gene Arg389Gly and Gly49Ser are associated with LVH in hypertensive patients.Methods: We tested our hypothesis in 2417 hypertensive patients which consisted of 1189 with LVH, 1228 without LVH. All subjects were genotyped for Arg389Gly and Gly49Ser polymorphisms.Results: Patients carrying the Arg389Arg genotype had increased left ventricular septal thickness （10.4±1.5mm vs 9.6±1.5mm,P<0.01 or 9.4±1.4mm,P<0.01, respectively）; left ventricular posterior wall thickness （10.4±2.4mm vs 9.6±2.4 or 9.7±2.9mm, P<0.01, respectively）; left ventricular mass index (51.6±13.3g/m²⁷ vs 44.6±12.9 g/m²⁷,P<0.01 or 43.2±14.4 g/m²⁷,P<0.01, respectively) and relative wall thicking （45.0±9.0% vs 42.6±8.1%, P<0.01 or 43.2±8.8%, P<0.01, respectively） as compared with the these carrying the genotypes Arg389Gly and Gly389Gly.These associations were independent of anthropometric factors and major clinical features and were confirmed in another hypertensive population （n=327）.Conclusions: Our findings indicate that the Arg389Gly polymorphism of the ADRB1 gene might be a genetic risk factor for the development of LVH in patients with hypertension. Background: Hypertrophic cardiomyopathy （HCM） is a primary autosomal dominant inheritant myocardial disorder with heterogeneity in clinical manifestations, natural history and prognosis. Even carrying an identical gene mutation, inter-and intra-family variations have been noticed worldwide in the presence and the severity of left ventricular hypertrophy and sudden death in patients with HCM. Modifier genes may contribute to the diversity. Previous studies in vitro or in vivo have indicated that beta（1）-adrenergic receptor plays an important role in the progression of cardiac hypertrophy. Celiprolol, a selectiveβ1-bloker, can attenuate cadiac myocyte hypertrophy both in vitro and in vivo, these effects are mediated via the NO-signal pathway by stimulating the expression of endothelial NO synthase （eNOS）. Studies also have proved that the eNOS plays a key role in the development of HCM. Our previous studies suggest that the polymorphisms of beta（1）-adrenergic receptor gene are associated with left ventricular hypertrophy in hypertension. The ADRB1 gene might be a modifier gene for the development of LVH in patients with HCM.Objectives:We tested whether SNPs in the ADRB1 gene associated with HCM.Methods:The hypothesis was tested in 267 patients with HCM and age-and sex-matched 816 healthy individuals. All subjects were genotyped for Arg389Gly and Gly49Ser polymorphisms.Results: No difference has been found in the frequency of the genotypes in the Arg389Gly and Gly49Ser polymorphisms of ADRB1 gene between patients with HCM and controls.Conclusions: The polymorphisms of ADRB1 gene were not associated with risk of HCM and other clinical phenotypes. The two variations of ADRB1 gene is not the genetic modifier for the development of HCM. Background: Left ventricular hypertrophy （LVH） is associated with cardiovascular morbidity and mortality, as well as all-cause mortality. LVH is also independently associated with risk of ischemic stroke. Although hypertension is a major cause of LVH, the degree of LVH does not parallel to the level of blood pressure, the duration of hypertension, or reversal of hypertensive LVH by pharmacological treatments. This implies that other factors may be involved in LVH in addition to blood pressure. It has been reported that genetic factors account for 60% of blood pressure-independent cardiac mass variances. Previous studies in vitro and vivo have proved that the stimulation of calcineurin can lead to cardic hypertrophy. The activity of calcineurin is regulated by many proteins such as cGMP-dependent protein kinaseⅠ（PKGⅠ）, heme oxygenase-1（HO-1）, modulatory calcineurin-interacting protein 1（MCIP1） and glycogen synthase kinase 3 beta（GSK3β）. Studies also have reported that PKGⅠ、HO-1、MCIP1 and GSK3βplay an important role in the progression of cardiac hypertrophy.We selected these genes as our candidate genes to study their association with LVH.Objectives: We hypothesized that polymorphisms of rs10995555、rs10822178 and rs4542348 of PKGⅠgene, rs2071747、rs17884059、rs17879895 and rs9282700 of HO-1 gene, rs8133540 of MCIP1 gene and rs334558、rs2276708和rs3755557 of GSK3βgene may modify the diversity of LVH. To test our hypothesis, the associations of these polymorphisms with cardiac hypertrophy were tested in case-control studies.Methods: We tested our hypothesis in 2696 hypertensive patients consisted of 1271 with LVH, 1425 without LVH, and 720 healthy individuals as controls. All subjects were genotyped for rs 10822178 （-2712A/T） polymorphism and about 500 subjects were genotyped for all the other polymorphisms. Results: We found that the AA+AT genotype at the position -2712 conferred a 1.7-fold risk for LVH （OR 1.70, 95%CI 1.18-2.47, p=0.005）, In the hypertensive patients, the AA and AT genotype carriers had a significant increase in their interventricular septal wall thickness （10.7±1.3mm for TT versus either 11.5±1.3mm for AA, P<0.01 or 11.2±1.4mm for AT, P<0.01 respectively in the hypertension patients with LVH; 9.2±1.6mm for TT versus either 9.9±1.6mm for AA, P<0.01 or 10.1±1.6mm for AT, P<0.01 respectively in the hypertension patients without LVH） and left ventricular mass index (57.4±11.7g/m^2.7 for TT ,61.8±15.8g/m^2.7 for AA, P<0.05 or 61.4±10.7g/m^2.7 for AT, P < 0.05 respectively in the hypertension patients with LVH; 46.8±13.8g/m^2.7 for TT, 48.8±16.8g/m^2.7 for AA, P<0.01 or 48.7±15.6g/m^2.7 for AT, P<0.01 respectively in the hypertension patients without LVH) after adjustment of age, sex, systolic and diastolic blood pressure and body mass index. No significant association was found between the other polymorphisms and echocardiographic variables in both hypertensive patients and in controls （P>0.05）.Conclusions Our findings indicate that the -2712A/T polymorphism of the PKGⅠgene might be a genetic risk factor for the development of LVH in patients with hypertension.更多还原