先天性房间隔缺损致病基因KLF13新突变的识别与功能分析

目的：探索房间隔缺损致病基因KLF13新突变。方法：对175例先天性房间隔缺损患儿和217名健康者的KLF13基因进行测序分析以发现新的致病突变。克隆KLF13基因,构建野生型KLF13表达质粒KLF13-pcDNA3.1,通过定位诱变获得突变型KLF13-pcDNA3.1,转染NIH3T3细胞,通过报告基因分析研究突变体的功能特性。结果：在1例散发性先天性房间隔缺损患儿发现KLF13基因新突变,即NM＿015995.4:c.85G>T; p.(Glu29*)突变。该突变不存在于217名健康者。生化分析表明突变型KLF13对靶基因ACTC1的转录激活功能丧失。结论：发现KLF13基因功能丧失性新突变可导致先天性房间隔缺损,这对先天性房间隔缺损的个体化医学防治有潜在的临床意义。     

心脏转录因子GATA4与心房颤动的关系

心脏转录因子GATA4是一种在心脏中大量表达的锌指转录因子,在心血管发育、心肌重构与肌细胞凋亡方面发挥着重要的生理作用,GATA4基因突变可导致多种先天性心脏病。近年来的研究显示,GATA4基因突变也可导致心房颤动（AF）。本文拟就GATA4的生理功能及其与AF的关系进行综述,旨在便于理解AF新的分子机制,从而有助于AF的早期预防和个体化治疗。     

特发性心房颤动致病基因PRRX1新突变的发现及功能分析

目的：探索特发性心房颤动（房颤）致病基因PRRX1新突变并分析其功能。方法：收集192例特发性房颤患者和212名健康者的外周静脉血标本,提取基因组DNA,测序分析PRRX1基因以发现致房颤突变。克隆PRRX1基因,构建其野生型表达载体,通过定位诱变获得突变体,转染Hela细胞,通过双荧光报告基因分析其功能特性。结果：在其中1例特发性房颤患者发现PRRX1基因新突变,即NM＿022716.4:c.425T>C; p.(Phe142Ser)突变。该突变不存在于212名志愿者,也不存在于其余191例房颤患者中。功能分析显示突变型PRRX1对靶基因SHOX2的转录激活作用显著降低。结论：发现房颤致病基因PRRX1新的功能丧失性突变,对房颤的精准预防具有潜在的临床意义。     

转录因子KLF6在肝病中的作用

转录因子Kruppel-like factor 6(KLF 6)广泛涉及到细胞增殖、分化、凋亡以及生长相关信号,且通过调节增殖分化在哺乳动物细胞内环境中起重要作用。本文就KLF 6在肝病中的一些作用进行简要综述。     

特发性心房颤动相关TBX5基因新突变的识别

目的:识别特发性心房颤动(房颤)相关TBX5基因新突变。方法:入选特发性房颤患者116例及健康对照者200名,获取临床资料和外周静脉血标本,抽提全部研究对象的基因组DNA,扩增TBX5基因的全部编码外显子及其侧翼内含子,对扩增片段进行测序以寻找变异。检索PubMed和SNP数据库以明确所发现基因变异的新颖性。应用MUSCLE软件分析多物种TBX5蛋白,以显示被改变氨基酸在进化上的保守性,并应用在线程序MutationTaster和PolyPhen-2分析基因变异的致病性。结果:在1例家族史阴性的特发性房颤患者发现了1个TBX5基因变异,其TBX5基因编码核苷酸序列第314位的腺嘌呤变成了胸腺嘧啶(c.314AT),所编码蛋白的氨基酸序列第105位的天冬氨酸变成了缬氨酸(p.D105V)。该突变不存在于200名对照者,也不存在于PubMed和SNP数据库中。多序列比对分析显示第105位的天冬氨酸在进化上完全保守。在线程序分析表明所识别的基因变异具有致病性。结论:发现了1个特发性房颤相关TBX5基因新突变,提示TBX5基因突变可能是特发性房颤的少见遗传病因。     

SHOX2基因与特发性心房颤动的关系研究

目的:研究SHOX2基因与特发性心房颤动(IAF)的关系。方法:收集178例汉族IAF患者和218名匹配的健康对照者。通过聚合酶链反应-DNA测序分析SHOX2基因的编码外显子及剪接序列。将测出的序列与核苷酸数据库中的SHOX2序列进行对比,查找SHOX2基因突变。通过在线计算机程序MUSCLE评估突变氨基酸进化上的保守性,应用PolyPhen-2、MutationTaster和PROVEAN软件分析SHOX2基因突变的致病性。结果:在1例IAF患者中发现SHOX2基因新突变,c.632GC (p.Trp211Ser),该错义突变不存在于218名健康对照者中,多物种SHOX2蛋白序列比对分析显示被改变氨基酸在进化上完全保守,致病性预测表明所识别的SHOX2基因突变具有致病性。结论:c.632GC是基因新突变,对IAF的早期防治具有潜在的临床意义。     

KLF6、Sp1蛋白在肝癌、肝硬化组织中的表达及意义

目的研究转录因子KLF6、Sp1在人肝细胞癌与肝硬化组织中的表达和意义。探讨KLF6、Sp1在肝癌、肝硬化中发生发展的作用机制及KLF6与Sp1之间的相关性。方法用免疫组化法对51例肝癌组织、35例癌旁肝硬化组织、10例良性病变而切除的正常肝组织转录因子KLF6、Sp1进行蛋白检测。结果KLF6、Sp1蛋白在肝癌组织表达率高于癌旁肝硬化组织，正常肝组织中全部呈阴性表达（P〈0．001）。结论KLF6、Sp1蛋白过表达在肝细胞癌、肝硬化的发生发展中可能起重要作用，在肝硬化组织中KLF6与Sp1具有正相关性。     

生长分化因子-15在心房颤动中的研究及应用进展

生长分化因子-15作为心血管疾病的新型生物标志物,在心血管疾病诊断、进展和预后中发挥重要预测价值。目前发现生长分化因子-15与心房颤动的发生、血栓形成、出血风险和预后相关,被认为是心房颤动的新型标志物。现就生长分化因子-15在心房颤动中的研究及应用进展做一综述。     

miR-194通过调控KLF15表达降低缺氧诱导的心肌细胞损伤

目的 探讨miR-194对缺氧诱导的心肌细胞损伤的影响及其分子机制.方法 建立心肌细胞缺氧组,缺氧条件为37℃、95％N2+5％CO2处理48 h,不作任何处理的细胞作为对照(Control)组;设置miR-con组(转染miR-con)、miR-194组(转染miR-194 mimics)、anti-miR-con组...     

KLF15在心血管疾病中的研究进展

Krüppel样因子15(KLF15)是包含锌指结构域的Krüppel样因子(KLF)家族中的重要一员。研究显示KLF15通过调控各种信号传导通路以及能量代谢在心血管疾病中发挥重要作用。例如KLF15可以通过影响肌细胞增强因子2(MEF2)或转化生长因子β(TGF-β)等发挥抗心肌重塑的作用,且KLF15是维系室性心律失常与昼夜节律关系的关键因子。本文综述了KLF15在心脏中的生理病理作用以及其在心血管疾病中的最新研究进展。     

解离素-金属蛋白酶15与慢性心房颤动心房结构重构的关系

目的探讨解离素-金属蛋白酶15(ADAM15)与慢性心房颤动(房颤)心房结构重构的关系。方法选择30例心外科手术患者,按有无房颤病史分为房颤组(n=15)和无房颤组(n=15)。取患者右心耳心肌组织后经Masson染色测定组织胶原容积分数(CVF)、RT-PCR法检测ADAM15基因mRNA的表达、Western blot法检测ADAM15蛋白的表达。结果与无房颤组比较,房颤组左心房直径增大[(41.5±10.4)mmvs(49.6±5.0)mm,P0.05]、CVF明显升高(11.67±3.35vs42.38±9.79,P0.01)、ADAM15mRNA(0.51±0.04vs1.20±0.06,P0.01)及蛋白表达(1.19±0.05vs2.61±0.16,P0.01)上调。ADAM15蛋白与左房直径(r=0.88,P0.01)、房颤持续时间(r=0.83,P0.01)及CVF(r=0.78,P0.05)呈正相关。结论AD-AM15可能参与心房颤动时心房的结构重构。     

The "missing" link in atrial fibrillation heritability

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, represents a major health burden to individuals and health care system within the Western world. The lifetime risk for the development of AF at age 40 years has been estimated to be approximately 1 in 4. Atrial fibrillation is associated with substantial morbidity and a 2-fold increased risk of mortality. Given its increasing prevalence with age, coupled with the aging population, the number of Americans affected with AF is expected to increase from approximately 2.3 million in the year 2000 to nearly 16 million by 2050. This AF epidemic is further complicated by the lack of highly effective therapies. One reason for the lack of effective therapies for AF stems from incomplete understanding of the complex pathophysiology of the arrhythmia. Atrial fibrillation has often been regarded as a condition that occurs in the context of atrial electrical and structural remodeling that can result from cardiac and systemic disorders. However, up to 30% of patients have no obvious cause and are said to have idiopathic or “lone” AF. Up until recently, AF was considered to be a sporadic, nongenetic disorder, but we and others have shown that lone AF has a substantial genetic basis. Mutations in genes encoding cardiac ion channels (KCNQ1, KCNE1-5, KCNJ2, KCNA5, and SCN5A), gap junctions (GJA5), and signaling molecules (atrial natriuretic peptide, nucleoporins [NUP155]) have been reported in isolated cases and small kindreds. The advent of the human genome and HapMap projects and high-throughput genotyping has fundamentally accelerated our ability to discover the genetic contribution to common variation in human disease. In 2007, a genome-wide association study identified 2 genetic variants that associated with AF. More recently, 2 additional AF loci on chromosomes 16q22 and 1q21 have been identified. It is quite likely, however, that the effects of alleles in many genes contribute to common complex diseases such as AF. The overall AF risk associated with common variants identified by the genome-wide association study approach is small (odds ratios, 1.1-2.5) and explains less than 10% of the heritability in lone AF. This raises the possibility that rare independent variants with large effects strong effects may account for a large fraction of the risk for lone AF.     

心房颤动犬心房肌肾素-血管紧张素系统改变

目的探讨慢性心房快速起搏诱发心房颤动(房颤)犬心房肌肾素血管紧张素系统(RAS)的改变。方法13只犬随机分为假手术组(n=6)和起搏组(n=7)。起搏组犬无菌开胸后在右心房缝植5对心外膜记录电极,电极尾端经皮下由犬背部穿出;在右心耳缝植螺旋型起搏电极,连接实验用AOO高频起搏器(400次/min),心房快速起搏6周,建立房颤犬模型;假手术组犬仅缝植心外膜记录电极和起搏电极而不起搏。经心外膜电极记录各组犬房颤诱发情况;采用放射免疫方法检测两组犬左心房及右心房组织血管紧张素Ⅰ(AngⅠ)、血管紧张素Ⅱ(AngⅡ)含量及肾素活性;采用逆转录聚合酶链反应(RTPCR)检测两组犬心房肌肾素、血管紧张素原和血管紧张素转换酶mRNA表达水平改变。结果(1)起搏组7只犬均经短阵快速刺激(burstpacing)诱发出房颤,房颤诱发率和平均持续时间较假手术组显著增加(P<0.01);(2)起搏组犬心房肌AngⅠ、AngⅡ含量较假手术组犬心房肌明显升高(P<0.01),肾素活性亦显著增加(P<0.01);同一组犬左心房与右心房组织AngⅠ、AngⅡ含量及肾素活性差异无统计学意义(P>0.05);(3)起搏组犬心房肌肾素、血管紧张素原和血管紧张素转换酶mRNA表达较假手术组犬心房肌显著上调(P<0.01)。结论慢性心房快速起搏诱发房颤犬心房肌AngⅠ、AngⅡ含量及肾素活性显著增加,可能是局部RAS基因表达上调的结果,提示房颤伴随心房肌RAS激活。     

Angiotensinogen polymorphisms and acquired atrial fibrillation in Chinese

Genetic predisposition may be underlying the prevalence of acquired atrial fibrillation (AF). We investigated the association between polymorphism in angiotensinogen (AGT) and angiotensin-converting enzyme gene and risk of acquired AF in a pair-matched case-control study conducted in Chinese Hans. We selected 9 single nucleotide polymorphisms (SNPs) in the AGT gene and 3 SNPs in the angiotensin-converting enzyme gene using a tagging-SNP strategy. We observed significant association between tagging-SNP rs699 (M235T), located in exon 2 of the AGT gene, and AF. The AA genotype of rs699 increased the risk of AF by 70% (95% confidence interval, 1.01-2.85; P = .044) under a recessive model (AA vs AG + GG). The significance remained after controlling for covariates age, smoking, body mass index, hypertension, diabetes, and left atrial dimension, with an increased risk of AF by 90% (95% confidence interval, 1.04-3.46; P = .036). We provide evidence that polymorphism in AGT gene may confer predisposition to acquired atrial fibrillation in Chinese Hans.     

快速右心房起搏致犬心房迷走神经重构的研究

目的 通过对快速心房起搏犬的神经相关因子的研究,观察右心房快速起搏48 h是否引起神经重构及其在心房颤动(房颤)中的作用.方法 健康杂种犬12只,随机分为房颤组(6只)和对照组(6只).右心房起搏600次/min、持续48 h.通过一种在发芽轴突生长丘中表达的蛋白质(GAP-43)和乙酰胆碱转移酶(CHAT)来了解心脏神经萌发和迷走神经的重构.结果 在房颤犬的左心房、左心耳、右心房和右心耳,GAP-43和CHAT的神经密度同对照组相比明显增高,差异均有统计学意义(P<0.05).此外,房颤犬的右心房GAP-43和CHAT的神经密度与左心房有明显差异(P<0.05),显微镜下显示每个样点心脏神经不均匀分布.结论 48 h持续起搏犬右心房形成阵发性房颤,可见明显的神经萌发和迷走神经重构且不均一分布.     

白藜芦醇对快速起搏右心房诱发的持续性心房颤动猪心房结构重构的影响

目的 观察快速起搏猪右心房制备持续性心房颤动（AF）的效果,探讨白藜芦醇（RES）干预对持续性AF猪的心房结构重构的影响.方法 18只小家猪（雌雄不拘）按完全随机设计的分组方法（采用动物编号和随机分组表）分为起搏组（ATP组）、假手术组（Sham组）和RES干预组各6只,采用Seldinger血管穿刺技术送入双极电极至右心房并连接实验用起搏器（AOO）,ATP组和RES干预组的右心房快速起搏（500次/min）2周,制备持续性AF实验模型.3组猪分别于起搏前和起搏2周后进行电生理和经胸壁超声心动图检查,以检测AF的持续时间、左右心房大小及左心房收缩末面积.RES干预组猪于起搏前1周开始服用RES（2.5 mg·kg-1·d-1）.起搏2周后取各组猪的左右心房组织标本,观察心房组织形态学和间质纤维化的改变,用免疫组织化学分析软件计算胶原容积分数（CVF）来反映间质纤维化程度.结果 （1）起搏2周后,ATP组AF的发生率较RES干预组明显升高（100％比66.7％,x2=10,P＜0.01）、持续时间延长[（26.41±9.89）min比（9.56±1.36） min,F=10.7,P=0.01].（2）起搏2周后,ATP组和RES干预组猪的左右心房明显比起搏前增大;但RES干预组的左心房收缩末面积明显低于ATP组[（599.2±8.7） mm2比（744.3±29.9） mm2,F=130.61,P＜0.01].（3）RES干预组左右心房组织CVF明显低于ATP组（56％±6％比73％±7％;59％±6％比75％±7％,均为P＜0.01）.结论 快速起搏猪右心房可成功制备持续性AF模型;RES干预可以明显抑制快速起搏右心房诱发的持续性AF猪的心房结构重构,减少AF的发生.     

先天性房间隔缺损相关GATA6基因新突变的识别

目的：识别先天性房间隔缺损（ASD）相关GATA6基因新突变。方法：收集110例先天性AsD患者和200名健康对照者的临床资料和血标本,使用DNA纯化试剂盒提取基因组DNA。通过聚合酶链反应扩增GATA6基因的编码外显子和其两侧的部分内含子,应用双脱氧核苷链末端合成终止法进行DNA测序。将所测序列与GenBank数据库中的GATA6基因序列进行比对,识别GATA6基因突变。分别借助在线程序MUSCLE和MutationTaster评估突变氨基酸的保守性和致病性。结果：在1例家族史阴性的先天性ASD患者发现了1种新的GATA6基因杂合错义突变,即P．Q363E突变,突变率约为0．91％。该突变不存在于200名健康对照者,多物种序列比对显示,被改变氨基酸在进化上高度保守,致病性预测表明这种变异为致病性突变。结论：发现ASD相关GATA6基因新突变,有助于揭示ASD新的分子机制。     

Mechanism of recurrence after radiofrequency catheter ablation of atrial fibrillation guided by complex fractionated atrial electrograms

Background A better understanding of the mechanisms of recurrent atrial fibrillation (AF) after radiofrequency ablation of complex, fractionated atrial electrograms (CFAEs) may be helpful for refining AF ablation strategies. Methods and results Electrogram-guided ablation (EGA) was repeated in 30 consecutive patients (mean age = 59 ± 8 years) for recurrent paroxysmal AF, 10 ± 4 months after the first ablation. During the first procedure, CFAEs were targeted without isolating all pulmonary veins (PVs). During repeat ablation, all PVs and the superior vena cava (SVC) were mapped with a circular catheter and the left atrium was mapped for CFAEs. EGA was performed until AF was rendered noninducible or all identified CFAEs were eliminated. During repeat ablation, ≥1 PV tachycardia was found in 83 PVs in 29 of the 30 patients (97%). Among these 83 PVs, 63 (76%) had not been completely isolated previously. During repeat ablation, drivers originating in a PV or PV antrum were identified only after infusion of isoproterenol (20 μg/min) in 12 patients (40%). At 9 ± 4 months of follow-up after the repeat ablation procedure, 21 of the 30 patients (70%) were free from recurrent AF and flutter without antiarrhythmic drugs. Conclusions Recurrence of AF after EGA is usually due to PV tachycardias. Therefore, it may be preferable to systematically map and isolate all PVs during the first procedure. High-dose isoproterenol may be helpful to identify AF drivers.