Gender-specific association of the angiotensin converting enzyme gene with Alzheimer's disease

We measured human evoked magnetic fields to binaural sounds with an interaural time delay as a cue for auditory localization. By analyzing the topography of auditory-evoked magnetic fields in the middle-latency, we demonstrated that particular cortical regions represent the direction of sound localization by their activity level. Upon presenting a binaural sound, the first representations were found in the middle frontal region as well as the superior temporal region of the right hemisphere approximately 19 ms after the stimulation, but their patterns differed. Other cortical regions including the prefrontal and parietal spatial areas were affected within roughly 60 ms. The results showed that the right hemisphere is dominant even in the preattentive stage of auditory spatial processing of sounds from different directions.     

Gender-specific association of the angiotensin converting enzyme gene with Alzheimer's disease

Epidemiological studies have demonstrated that risk factors for vascular disease are also risk factors for Alzheimer's disease (AD). The gene for the angiotensin converting enzyme (ACE) has recently been reported to be associated with risk for AD. We have investigated the possibility of such an association in 98 clinic-based and 73 community-based AD cases versus 175 community-based controls and find a gender-specific association of ACE genotype with AD in the female clinic population. These data suggest that gender may interact with genetic factors to influence risk for AD. Gender-specific risk for AD has been previously reported, and a biological rationale for involvement of ACE in the AD process is supported by studies exploring the relationship between AD and vascular risk factors such as hypertension. However, the results may also be a consequence of the known anomalies that arise in genetic association studies as a consequence of sample selection.     

Lack of association between the CYP46 gene polymorphism and Italian late-onset sporadic Alzheimer's disease

Recent studies have provided evidence toward the possible involvement of brain cholesterol homeostasis in late-onset Alzheimer's disease (LOAD). We analyzed an intronic T-->C substitution (rs 754203) of the cholesterol 24S-hydroxylase (CYP46) gene, encoding an enzyme acting on brain cholesterol turnover, which has been recently associated with an increased risk of AD, dependent or not on Apolipoprotein E (ApoE) genotype. No significant association was found for the CYP46 polymorphism in LOAD compared to the controls, even after stratification for the presence/absence of the ApoE*4 allele. Our data do not support a role of the CYP46 polymorphism as a possible susceptibility factor for developing AD.     

血管紧张素转换酶基因多态性与中国汉族迟发性阿尔茨海默病的关系

目的：探讨血管紧张素转换酶（angiotensin I converting enzyme，ACE）基因插入（I）/缺失（D）多态性与阿尔茨海默病（Alzheimer disease，AD）的关系以及高血压对这种关系的影响。方法：采取病例-对照研究的方法，对象为96个符合精神疾病诊断和统计手册第4版（DSM-IV）诊断的AD病例和96名来自同一地区的性别、年龄匹配的非AD对照，用聚合酶链反应扩增，扩增产物经琼脂糖电泳溴化乙锭染色，进行多态性检测。结果：在病例和对照之间ACE基因型和等位基因分布差异有显著性，同样在有高血压的AD患者和对照之间基因型分布的差异有显著性；但血压正常的AD患者和对照之间基因型分布差异无显著性。结论：ACE基因的多态性与AD发病风险有关，但II基因型作为危险因素仅限于高血压的AD患者。     

血管紧张素转换酶基因多态性与佳木斯地区阿尔茨海默病的关系

背景：血管紧张素转换酶作为肾素-血管紧张素系统的关键酶,通过影响P物质降解等机制参与阿尔茨海默病的发生与发展。 目的：分析血管紧张素转换酶基因多态性与阿尔茨海默病的关系,探讨性别、高血压病对两者关系的影响。 方法：纳入96例阿尔茨海默病患者,102例年龄、性别等具有可比性的正常人作为对照组。采集血液,抗凝后进行DNA抽提,用PCR反应进行扩增,20 g/L琼脂糖凝胶电泳,紫外光下观察结果,分别计算II、DD型纯合子及ID杂合子基因型及基因型频率。在此基础上,综合分析收集的相关临床资料,进行性别及血压分层分析。 结果与结论：阿尔茨海默病组与对照组血管紧张素转换酶基因型和等位基因频率差异有显著性意义,伴有高血压的阿尔茨海默病患者与对照组基因型和等位基因频率差异有显著性意义;不同性别分层及血压正常的阿尔茨海默病组与对照组基因型和等位基因频率差异无显著性意义。提示血管紧张素转换酶基因多态性与阿尔茨海默病的发病有关,其中II基因型可能是阿尔茨海默病发病的危险因素,血管紧张素转换酶基因型可能是阿尔茨海默病伴高血压病的危险因素。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

Lack of association between PRNP 1368 polymorphism and Alzheimer's disease or vascular dementia

Background  

Polymorphisms of the prion protein gene (PRNP) at codons 129 and 219 play an important role in the susceptibility to Creutzfeldt-Jakob disease (CJD), and might be associated with other neurodegenerative disorders. Several recent reports indicate that polymorphisms outside the coding region of PRNP modulate the expression of prion protein and are associated with sporadic CJD, although other studies failed to show an association. These reports involved the polymorphism PRNP 1368 which is located upstream from PRNP exon 1. In a case-controlled protocol, we assessed the possible association between the PRNP 1368 polymorphism and either Alzheimer's disease (AD) or vascular dementia (VaD).     

Lack of association between polymorphisms in the testis-specific angiotensin converting enzyme gene and male infertility in an Asian population

Angiotensin converting enzyme (ACE) is a membrane-bound dipeptidyl carboxy-peptidase that generates vasoconstricting angiotensin II and inactivates vasodilating bradykinin. The ACE gene encodes two isozymes: the somatic isozyme (sACE) is found in many tissues including vascular endothelial cells, whereas the testis-specific isozyme (tACE) is expressed exclusively in developing spermatids and mature sperm. Thus, ACE might have physiological functions in addition to blood pressure regulation. Male mice lacking tACE activity show reduced fertility, indicating its importance in male fertility. In this study, we screened five recently defined tACE gene polymorphisms in 90 Singapore Chinese men with infertility and 84 fertile controls using PCR-based restriction fragment length polymorphism and DNA sequencing. However, only one of these polymorphisms was identified in both patient and control groups, the frequency of which was not significantly different in patients and controls. Thus, these ACE gene polymorphisms are unlikely to contribute to the pathogenesis of male infertility in the Singapore Chinese population.     

Insertion/deletion polymorphism of angiotensin converting enzyme gene in Kawasaki disease

Polymorphism of angiotensin converting enzyme (ACE) gene is reported to be associated with ischemic heart disease, hypertrophic cardiomyopathy, and idiopathic dilated cardiomyopathy. In this study, we investigated the relationship between Kawasaki disease and insertion/deletion polymorphism of ACE gene. Fifty five Kawasaki disease patients and 43 healthy children were enrolled. ACE genotype was evaluated from each of the subjects' DNA fragments through polymerase chain reaction (PCR). Frequencies of ACE genotypes (DD, ID, II) were 12.7%, 60.0%, 27.3% in Kawasaki group, and 41.9%, 30.2%, 27.9% in control group respectively, indicating low rate of DD and high rate of ID genotype among Kawasaki patients (p<0.01). Comparing allelic (I, D) frequencies, I allele was more prevalent in Kawasaki group than in control group (57.3% vs. 43.0%, p<0.05). In Kawasaki group, both genotype and allelic frequencies were not statistically different between those with coronary dilatations and those without. ACE gene I/D polymorphism is thought to be associated with Kawasaki disease but not with the development of coronary dilatations.     

载脂蛋白E基因多态性与散发性老年性痴呆病的关系

目的:探讨载脂蛋白E(apoE)外显子4和增强子元件基因多态性与散发性Alzheimer病(AD)的关系。方法:应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术分别检测apoE外显子4和内含子1内增强子元件(IE1)基因型。结果:(1)ApoE外显子4基因多态性:AD组ε3/4基因型频率(0.381)和ε4等位基因频率(0.226)显著高于对照组(P＜0.05)。(2)ApoEIE1基因多态性AD组G/G基因型频率(0.595)显著高于对照组(P＜0.05)。(3)有apoEε4个体患AD风险为无ε4个体的3倍,比值比为2.932,95%可信区间1.379~6.226;G/G基因型个体患AD风险为G/C、C/C个体的2倍,比值比为2.223,95%可信区间1.075~4.599;经统计分析发现apoEε4与IE1G/G呈非常显著性正相关(P＜0.01);排除apoEε4后发现IE1G/G与AD发病风险无关。结论:ApoEε4等位基因是个体发生AD的危险因素,IE1G/G增加AD发病风险是因其与ε4相关所致。     

No genetic association between alpha-2 macroglobulin I1000V polymorphism and Japanese sporadic Alzheimer's disease

Alpha-2 macroglobulin (A2M) is a serum pan-protease inhibitor that is related with the pathogenesis of Alzheimer's disease (AD) through its ability to mediate amyloid beta degradation. Recently, it has been reported that the I1000V polymorphism in A2M gene might increase the risk of AD. In the present study, we investigated this mutation in 95 healthy controls and in 111 sporadic AD cases by polymerase chain reaction-restriction fragment length polymorphism method in order to study this hypothesis in the Japanese AD population. Allelic frequencies with the I1000V polymorphism in the gene were 7.4 and 6.8% in the control and AD groups, respectively. Our results failed to demonstrate an association between this polymorphism and Japanese sporadic AD, and the A2M I1000V mutation does not seem to be a risk factor per se for sporadic AD.     

Lack of association between angiotensin I-converting enzyme insertion/deletion gene functional polymorphism and panic disorder in humans

Family and twin studies have indicated that genes influence susceptibility to panic disorder, but the genes involved remain unknown. The neuropeptide angiotensin II has been found to be involved in anxiety and regulation of respiration which are important in the pathophysiology of panic attacks. Assuming that angiotensins may be candidate genes in panic disorder, we analyzed the association between panic disorder and angiotensin I-converting enzyme (ACE) insertion (I)/deletion (D) gene functional polymorphism. We recruited 101 patients with panic disorder diagnosed according to DSM-IV criteria, and 184 control subjects in the study. No significant differences in the frequency of the genotype or allele in the polymorphism between patient and control groups were found (genotype, chi(2)=0.56, d.f.=2, P=0.77; allele, chi(2)=0.074, d.f.=1, P=0.78). This study suggests that the ACE I/D gene polymorphism is not directly associated with panic disorder in our Japanese patient group.     

No genetic association between tumour necrosis factor receptor II 196R polymorphism and Japanese sporadic Alzheimer's disease

Recent studies have reported that acute effects of tumour necrosis factor (TNF), a pro-inflammatory cytokine, are limited by binding to a soluble receptor, TNF receptor II, and the G allele at position 196 in exon 6 of the TNF receptor II gene (TNFRII 196R) has been associated with auto-immune diseases. Since complex interactions among cytokines have been suggested around senile plaques in Alzheimer's disease, TNF might be associated with ageing and the pathophysiology of Alzheimer's disease. We examined the TNFRII 196R polymorphism in 243 Japanese sporadic Alzheimer's disease cases and 106 control cases using a polymerase chain reaction-restriction fragment length polymorphism method. Allelic frequencies with TNFRII 196R T/G polymorphism were 28.3% and 27.4% in the control and Alzheimer's disease groups, respectively. The results showed no genetic association between TNFRII 196R polymorphism and Alzheimer's disease. The TNFRII 196R G allele does not appear to be associated with Alzheimer's disease susceptibility in a Japanese population.     

Lack of association of angiotensin I-converting enzyme gene polymorphism and premature myocardial infarction in Mauritian Indians

Eighty-five young Mauritian Indians, male survivors of premature myocardial infarction (MI) and thus belonging to a high risk group, were compared with 108 stringently selected controls for a possible association between premature MI and an insertion/deletion (I/D) polymorphism in the gene encoding angiotensin I-converting enzyme (ACE). The frequency of the D allele was 0.42 in the MI group and 0.43 in the control group, and thus no association between I/D polymorphism of ACE with susceptibility to early-onset MI was found in this population group. Other gene components of the renin-angiotensin system and lipid metabolism need to be explored to understand the genetic factors involved in causing MI at an early age.     

西藏藏族人群血管紧张素转换酶基因多态性分布

目的:探讨西藏拉萨、那曲地区藏族健康人群血管紧张素转换酶(ACE)基因第16内含子287bpAlu顺序插入/缺失(I/D)多态性分布。方法:采用聚合酶链反应(PCR)方法检测ACE基因型。结果:76例拉萨藏族人ACE基因型频率分别为Ⅱ=0．395,ID=0．316,DD=0．289,等位基因频率分别为Ⅰ=0．553,D=0．447。81例那曲藏族人ACE基因型频率分别为Ⅱ=0．346,ID=0．444,DD=0．210,等位基因频率分别为Ⅰ=0．568,D=0．432。结论:拉萨、那曲地区藏族人ACE基因型及等位基因频率分布无显著差异;西藏藏族与英国白人和美国黑人相比基因型及等位基因频率均存在显著性差异,但与韩国人及日本人相似。     

Association of angiotensin converting enzyme gene polymorphism with tachycardia cardiomyopathy

Despite incessant tachycardia, not all patients develop tachycardia-mediated cardiomyopathy. The cardiac renin-angiotensin system may be involved in cardiac remodelling and fibrosis. The level of angiotension-converting enzyme (ACE) in the serum is associated with a 287 bp insertion (I)/deletion (D) polymorphism in intron 16 of the ACE gene. The DD genotype is associated with increased serum ACE levels and a higher incidence of idiopathic dilated and ischemic cardiomyopathy. The objective of this study was to assess whether the ACE gene I/D polymorphism is responsible for development of tachycardia-mediated cardiomyopathy. We identified 20 consecutive patients with persistent tachycardia and cardiomyopathy who showed significant improvement in ejection fraction after rate control (group A, tachycardia cardiomyopathy group). We compared the I/D genotype frequency of group A with the gene frequency of a separate group of 20 patents who, despite rapid atrial arrhythmias had preserved left ventricular ejection fraction (group B, tachycardia without cardiomyopathy group). These two groups were then compared with 24 healthy normal volunteers (group C). After a mean follow-up of 30 months, group A patients showed improvement in ejection fraction from 20+/-7 to 43+/-9% (p<0.001). Group A had a significantly higher frequency of the DD genotype than groups B and C (p-value <0.035 and <0.009 respectively). The profile of group B patients was intermediate between normal and patients with tachycardia-mediated cardiomyopathy. I/D polymorphism of the ACE gene may account for cardiomyopathy secondary to tachycardia.     

Genetic association between alpha-2 macroglobulin and Japanese sporadic Alzheimer's disease.

Alpha-2 macroglobulin (encoded by the gene A2M) is a serum pan-protease inhibitor that may be related with the pathogenesis of Alzheimer's disease (AD) because of its ability to mediate amyloid beta degradation. Recently, several groups have reported that the five-nucleotides deletion in A2M gene at the 5' splice site of exon 18 might increase risk for AD. In the present study, therefore, this mutation was studied in 69 healthy controls and 55 sporadic AD cases by polymerase chain reaction- restriction fragment length polymorphism method. The allelic frequencies with the deletion (A2M-2) are 9.4 and 6.4% in the control and AD groups, respectively. There is no significant difference in the A2M-2 frequencies between the controls and sporadic AD cases. This is the first report to study the frequencies of A2M-2 in Japanese AD cases, suggesting its no genetic association with sporadic AD.     

Interleukin-10 promoter polymorphism in sporadic Alzheimer's disease

Proinflammatory cytokines and acute-phase proteins play an important role in Alzheimer's disease (AD) neurodegeneration, and common polymorphisms of genes controlling their high production have been shown to be associated with AD. Thus, AD patients display a proinflammatory genotype and the control of inflammation might play a protective role in AD development. By sequence-specific probes, we have evaluated the role of anti-inflammatory cytokine interleukin(IL)-10 in AD, by analysing in 132 AD patients and 213 healthy controls the prevalence of three different haplotypes, involving three single-nucleotide polymorphisms (SNPs) at -1082 (G-->A), -819 (C-->T) and -592 (C-->A) nucleotides of IL-10 promoter, associated with different IL-10 production. The percentage of -1082A carrier subjects was significantly increased among AD patients, and this increase was mainly due to the increase of ATA haplotype. Analysing these results according to the well-known genetic risk factor APOE-e4 allele, no significant differences were observed in SNP IL-10 allele distribution between AD patients carrying the genotype or not. So we may conclude that the presence of -1082A allele and in particular of -1082A/-819T/-592A haplotype, associated with a low production of anti-inflammatory cytokine IL-10, may be considered as an additive and independent genetic risk factor for AD.     

Lack of association between the APEX1 Asp148Glu polymorphism and sporadic amyotrophic lateral sclerosis

Impairments in DNA repair enzymes have been observed in amyotrophic lateral sclerosis (ALS) tissues, particularly in the activity of the apurinic/apyrimidinic endonuclease 1 (APEX1). Moreover, it was suggested that the common APEX1 Asp148Glu polymorphism might be associated with ALS risk. To further address this question we performed the present study aimed at evaluating the contribution of the APEX1 Asp148Glu polymorphism in sporadic ALS (sALS) risk and clinical presentation, including age and site of onset and disease progression. We screened 134 sALS Italian patients and 129 matched controls for the presence of the APEX1 Asp148Glu polymorphism. No difference in APEX1 Asp148Glu allele and genotype frequencies was found between the groups, nor was the polymorphism associated with age and site of onset or disease progression. Present results do not support a role for the APEX1 Asp148Glu polymorphism in sALS pathogenesis in the Italian population.     

Lack of association between rs597668 polymorphism near EXOC3L2 and late-onset Alzheimer's disease in Han Chinese

Recently, an international genome-wide association study (GWAS) additionally found rs597668 near EXOC3L2/BLOC1S3/MARK4 was a new genome-wide significance locus associated with late-onset Alzheimer's disease (LOAD) in Caucasians. Follow-up replication studies were conducted almost exclusively in Caucasians, and the effects of the risk locus in other populations are as yet unknown. This study investigated the GWAS-associated locus near EXOC3L2 in 1205 unrelated Northern Han Chinese subjects comprising 598 LOAD patients and 607 healthy controls matched for gender and age. The results showed no significant differences in the genotypic or allelic distributions of rs597668 polymorphism between LOAD cases and healthy controls (genotype: P = 0.653; allele: P = 0.603), even after stratification for apolipoprotein E (APOE) ?4 status and statistical adjustment for age, gender and APOE ?4 status. This study suggests that the rs597668 polymorphism near EXOC3L2 may not play a major role in the susceptibility to LOAD in the Northern Han Chinese population.     

Lack of genetic association between PPARG gene polymorphisms and Finnish late-onset Alzheimer's disease

Single nucleotide polymorphisms (SNPs) in diabetes related peroxisome proliferator-activated receptor gamma (PPARG) gene were investigated with a case-control approach. To examine the genetic association of this gene with Alzheimer's disease (AD) risk, we used the TaqMan technique to genotype eight SNP sites for PPARG gene, in 538 Finnish AD cases and 672 controls and conducted a single allele and genotypic distribution comparison as well as estimated haplotype frequencies between cases and controls. No significant differences in AD risk were found in single SNP and haplotype analyses for PPARG gene between the study groups. We conclude that PPARG gene does not play a major role in the genetic predisposition to AD in the Finnish population.