中国汉族人群对氧磷酶Q192R基因多态性与冠心病的相关性及危险因素对基因型影响的研究

目的:测定对氧磷酶(PON1)Q192R基因多态性及在人群中的分布,并分析不同基因型与冠心病(CHD)的关系,CHD常见危险因素对基因型亚组的影响。方法:应用聚合酶链反应-限制性片断长度多态性(PCR-RFLP)分析机聚丙稀酰胺凝胶电泳方法检测PON1多态性,等位基因频率计算采用计数法。对所得结果采用t检验、t′检验、或χ2检验进行统计学处理,统计分析用Sars软件。结果:PON1Q192R有QQ、QR、RR三种基因型,正常人的基因型频率分别为0.2000、0.4909、0.3091,Q、R等位基因频率分别为0.4500、0.5500,冠心病组QQ、QR、RR三种基因频率分别为0.2266、0.5313、0.2421,Q、R等位基因频率分别为0.4921、0.5079。吸烟对含R等位基因的基因型QR、RR是冠心病的独立危险因素,在冠心病组和对照组中血糖、血脂、饮酒、血压在各亚组中的影响均无明显相关性。结论:中国汉族人群(潍坊地区)PON1基因多态性和冠心病无关。吸烟可能是含R基因的基因型的人群患冠心病的易感因素。     

IL-4受体基因多态性与儿童过敏性紫癜肾炎的相关分析

目的探讨IL-4受体基因多态性与儿童过敏性紫癜肾炎（HSPN）的关系。方法采用聚合酶链反应-限制性酶切多态性方法检测131例HSPN组患儿和120例健康对照组儿童的IL-4Rα亚单位Q576R位点基因多态性。结果 HSPN组IL-4Rα亚单位QR＋RR基因型和R576等位基因频率均高于对照组（P〈0.05）。结论 IL-4Ra亚单位R576可能是HSPN患儿的危险因子。     

对氧磷酶1与2型糖尿病合并冠心病的关系

目的 :探讨对氧磷酶 -1(PON -1)在2型糖尿病 (T2DM )合并冠心病 (CAD)中的作用。方法 :应用聚合酶链式反应 -限制性片段长度多态性 (PCR -RFLP)方法鉴定天津地区汉族人的PON -1Q/R基因多态性的基因型 ,并测定血清PON -1活性。结果 :单纯T2DM组、单纯CAD组、T2DM合并CAD组和正常对照组PON -1Q/R基因多态性的基因型分布及等位基因频率差别无统计学意义(χ2分别为4 95和5 27,P>0.05)。前3组血清的PON -1活性均显著低于正常对照组(P<0.05) ,其中T2DM合并CAD组血清PON -1活性亦显著低于单纯CAD组和T2DM组(P<0.05)。结论 :PON_1Q/R基因多态性与T2DM并发CAD无相关性 ,而高血压病史和血清PON -1活性降低与T2DM并发CAD有关。提高血清PON -1活性有助于预防T2DM的大血管并发症     

PECAM-1单核苷酸多态性与中国人群冠心病的相关性

目的研究血小板内皮细胞黏附分子-1（PECAM-1）基因第2外显子单核苷酸多态性（SNP）与中国人群冠心病的相关性。方法选择90例冠心病患者及年龄、性别相匹配的115例正常对照组，采用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）方法检测PECAM-1基因型，比较两组基因型及等位基因频率分布。结果冠心病组V／V基因型频率（40．00％）明显高于对照组（23．48％）（P〈0．05）；与对照组相比，冠心病组V等位基因频率（58．89％）明显升高，L等位基因频率（41.11%）明显降低（P〈0．05）；吸烟使V／V基因型者冠心病发病危险度由2．17上升至3．50（P〈0．05）。结论PECAM-1基因第2外显子SNP与中国人群冠心病相关，V／V基因型可能是中国人群冠心病的遗传易患因子。     

血管紧张素原基因M235T多态性与冠心病关系的研究

目的　探讨中国苏皖地区人群血管紧张素原（AgT）基因型的分布及其与冠心病（CHD）的关系。方法　应用突变基因分离聚合酶链（MS-PCR）技术,对106例CHD患者、56例冠状动脉造影正常者以及30名健康献血员AgT基因M235T多态性进行检测。结果　病例组和对照组AgT基因型总体分布无显著差异,而病例组T等位基因频率（0.788）显著高于对照组（0.698）（P＜0.05）。结论　AgT基因M235T多态性中T等位基因是中国苏皖地区人群CHD发病的危险因素之一。     

云南省白族和汉族冠心病患者载脂蛋白E基因多态性研究

目的 探讨云南省确诊的白族和汉族冠心病（CHD）病人载脂蛋白E（ApoE）基因多态性的民族差异。方法 选择云南省确诊的冠心病病人，白族21例和汉族77例（其中80病人通过冠脉造影证实，18例病人有明确的心梗病史）。采用生物化学方法测定其血清血脂，应用聚合酶链反应-限制性片段长度多态性分析法，以Hhal内切酶及聚丙烯酰胺凝胶电泳确定ApoE基因多态性。结果 在白族CHD组和汉族CHD组均以ε3等位基因以及E3，3基因型最常见，两组之间E2／3、E3／3、E3／4基因型的分布未见统计学差异；白族组和汉族组中ε2、ε3、84等位基因频率比较无统计学差异（P〈0．05）；两组中含84等位基因携带者总胆固醇（TC）和低密度脂蛋白胆固醇和（LDL-C）显著高于其他基因型组，（P〈0．01）。结论在云南省白族和汉族人群之间ApoE基因型分布没有明显差异，白族和汉族人群中ε4等位基因是影响血清TC、LDL-C水平的重要遗传因素之一。     

TLR4基因多态性SNP896A〉G、SNP1196C〉T与冠心病的相关性研究

目的探讨吉林地区汉族人群TIJR4基因多态性与与冠心病的关系。方法运用单核苷酸多态性分析技术在328例无亲缘关系的吉林地区汉族人群（正常对照人群172例，冠心病156例）中检测TLR4基因3号外显子的SNP896A〉G、SNP1196C〉T多态性。结果吉林地区汉族人群中TLR4基因多态性SNP1196C〉T的基因型频率和等位基因频率在冠心病组和正常对照组问的分布存在显著性差异（P〈0．05）。结论吉林地区汉族人群TLR4基因多态性位点SNP1196C〉T与冠心病有相关性。     

冠心病患者I型对氧磷酯酶基因192 Gln／Arg多态性的研究

目的：探讨中国北方地区I型对氧磷酯酶（paraoxonase,PON1)基因192 Gln/Arg遗传多态性及其与冠心病发病的关系。方法：应用PCR－RFLP技术，检测49例老年CHD患者和38例对照者的PON1－192Gln/Arg基因多态性，等位基因以A／B表示。结果：各基因组（AA，AB，BB）分布在冠心病组：18.4%,51%,30.6%;对照组：39.5%,47.3%,13.2%。两组比较各基因型分布具有显著性差异（X^2=6.35,P=0.042);B等位基因在冠心病组明显增高（0.56vs.0.370);B等位基因携得（AB型＋B型）与AA型纯合子比较，两组间具有显著性差异（x^2=4.77,P=0.029).B等位基因是中国北方地区冠心病发病的危险因素(OR=2.19,95%CI:1.19-4.05)。结论：PON1基因192Gln/Arg遗传多态性与中国北方地区冠心病发病明显相关。该酶切位点多态性具有明显的种族差异。     

对氧磷酶1基因多态性与氯吡格雷抵抗的相关性研究进展

目的：为抗血小板药物氯吡格雷的临床应用和个体化给药提供参考。方法：检索国内、外最新相关文献,对对氧磷酶1（PON1）基因多态性与氯吡格雷抵抗的相关性的研究进展进行分析、归纳和总结。结果与结论：PON1基因多态性与氯吡格雷抵抗相关性的研究可用于心血管事件的个体预防和发病机制探索。PON1是氯吡格雷生物活化的关键酶,PON1基因Q192R单核苷酸多态性可以调控PON1的活性;且PON1基因多态性可能是氯吡格雷抵抗发生的重要影响因素。由于不同种族人群、不同试验方法及样本量的限制都会干扰两者的相关性,因此应在试验条件允许的情况下适当增加样本量;对不同种族人群的研究要从多方面进行分析,减少环境、生活方式等因素对两者的相关性的干扰。     

三磷酸腺苷结合盒转运子A1启动子区及7外显子基因突变与合并糖尿病的冠心病关联研究

目的首次研究汉族人群冠心病合并糖尿病与三磷酸腺苷结合盒转运子A1（ABCA1）基因启动子区-565C／T及7外显子R219K基因多态性关联分析。方法应用连接酶检测反应法对172例合并糖尿病冠心病患者及393例对照组测试-565C／T及R219K基因型。结果合并糖尿病冠心病患者-565C／T位点CC、CT及TT基因型频率分别为0．360（n=63）,0．482（n=83）,0．157（n=27）,与对照相比,TT基因型及T等位基因频率分别为0．157vs0．163,0．398vs0．409（均P〉0．05）。R219K位点AA＋AG基因型合并糖尿病的冠心病组与对照组分别为0．65vs0．73,P=0．079。关联分析显示,AA基因型系冠心病保护性因素,[OR=0．428（95％C10．227—0．603）,P=0．009]。结论ABCA1基因-565C／T位点T等位基因与合并糖尿病的冠心病无关联,R219K的A等位基因在合并糖尿病的冠心病组频率较低,提示A等位基因系冠心病保护性因子。     

Frequency of paraoxonase 192/55 polymorphism in an Iranian population

Paraoxonase (PON1) is a serum enzyme that plays an important role in prevention of atherosclerosis and also protects against organophosphate-induced neurotoxicity. PON1 displays a high variability in human populations. In this study, PON1-192 and -55 polymorphisms and correlation to serum PON1 activity were investigated in 132 healthy Iranian individuals from Isfahan province. The genotype frequencies for PON1-192 were approximately 48% (QQ), 42.% (QR), and 10% (RR) and for PON1-55 17% (MM), 48% (ML), and 35% (LL). Thus, the frequencies of alleles R and L were 0.31 and 0.59, respectively. PON1 activity toward paraoxon was markedly affected in both polymorphic populations in the following order QQ < QR < RR genotype for PON1-192 and MM < ML < LL genotype for PON1-55. Neither polymorphism significantly affected PON1 activity toward phenylacetate. The RR/LL individuals had the highest PON1 activity and QQ/MM individuals the least. The QR/ML haplotype was the most frequent seen in Iranians, and the RR/MM and QR/MM haplotypes were absent in this population. In conclusion, the frequencies of PON1-192 and -55 polymorphisms in this Iranian population were different from those seen in other Asian populations from Japan and China but similar to those for European Caucasians.     

Effect of statin therapy on plasma high-density lipoprotein-cholesterol levels is modified by paraoxonase 1 in Chinese patients with coronary heart disease

1. We sought to determine the effects of Q192R polymorphism of paraoxonase 1 (PON1) gene on plasma high-density lipoprotein-cholesterol (HDL-C) levels and the response to statin therapy in Chinese patients with coronary heart disease (CHD). 2. Two hundred and thirty-six patients with CHD were treated with simvastatin 20 mg/day. Fasting serum lipids were determined before and after 12 weeks of treatment. 3. No significant differences were detected among the PON1 Q192R polymorphism with respect to plasma lipids. In addition, the effects of simvastatin to increase HDL-C levels were significantly greater in patients with the RR genotype compared with patients with the QR or RR genotypes (P < 0.05). 4. We conclude that the Q192R polymorphism of PON1 significantly modulates the HDL-C response to simvastatin in Chinese patients with CHD.     

Relationship between human paraoxonase-1 activity and PON1 polymorphisms in Mexican workers exposed to organophosphate pesticides

Paraoxonase-1 (PON1) is a serum enzyme which catalyzes the hydrolysis of organophosphate pesticides. In this study we conducted a cross-sectional study and reported on the distribution of three common genetic polymorphisms of the PON1 gene in a population of floriculture workers from Mexico as well as the association between those polymorphisms and other predictors with serum PON1 activity on paraoxon, diazoxon and phenylacetate. The genotype frequencies at position PON1₅₅ were 89% (LL), 10% (LM) and 0.6% (MM), at position PON1₁₉₂ they were 16% (QQ), 47% (QR) and 37% (RR), and 26% (TT), 42% (TC) and 32% (CC) at position PON1_−108. Thus, the frequencies of alleles L, Q and T were 0.94, 0.40 and 0.47, respectively. The PON1₅₅ polymorphism had no significant effect on serum PON1 activity on any substrate. We found a significant association between the PON1₁₉₂ polymorphism and PON1 activity towards paraoxon and diazoxon, which increased in genotypes as follows: 192RR > 192QR > 192QQ for paraoxonase activity and, inversely, 192QQ > 192QR > 192RR for diazoxonase activity. The PON1₋₁₀₈ polymorphism also had a significant effect on PON1 activity level towards paraoxon in the following order among the genotype groups: −108CC > −108TC > −108TT. Serum PON1 activity towards diazoxon was not associated with the PON1₋₁₀₈ polymorphism but it was influenced by the intensity exposure to pesticides at the floriculture industry and the years of the occupational exposure to pesticides. No polymorphism significantly influenced serum PON1 activity on phenylacetate.     

Novel paraoxonase (PON1) nonsense and missense mutations predicted by functional genomic assay of PON1 status

Paraoxonase (PON1) has been termed an environmental response enzyme for its function in the detoxification of organophosphate pesticides, nerve agents and pharmaceuticals such as glucocorticoids and statins, as well as its cardioprotective role in breaking down oxidized LDL. PON1(192) genotype can be predicted with high accuracy from an examination of the two-dimensional plot of paraoxon and diazoxon hydrolysis rates [ 1]. Individuals for whom this functional genomic assay failed to predict PON1(192) genotype, or who had a low PON activity relative to others with the same genotype, were predicted to have genetic alterations that explained the inconsistency. Sequencing of the PON1 region of 23 Caucasian individuals detected a nonsense mutation changing amino acid 194 from a Trp to a stop codon (PON1(Trp194stop)). It was predicted that subjects who genotyped as PON1(192QR) but phenotyped as PON1(192QQ) or PON1(192RR) might carry the protein truncation mutation for which the defective product failed to be detected by the phenotyping assay. Screening of the five discordant subjects resulted in the detection of a single Caucasian carrying the stop codon, and determined its phasing on the PON1(192R) allele. Sequencing confirmed the change and revealed an additional subject with a likely deletion of the 5' end of the PON1 gene. Additional sequencing of 25 subjects with low PON1 activities identified two additional previously undescribed PON1 mutations, which may affect PON1 function: PON1(Pro90Leu) associated with the PON1(192Q) allele and PON1(Asp124missplice) associated with the PON1(192R) allele.     

PON1Q192R genetic polymorphism modifies organophosphorous pesticide effects on semen quality and DNA integrity in agricultural workers from southern Mexico

Pesticide exposure, including organophosphorous (OP) insecticides, has been associated with poor semen quality, and paraoxonase (PON1), an enzyme involved in OP deactivation, may have a role on their susceptibility, due to PON1 polymorphisms. Our objective was to evaluate the role of PON1Q192R polymorphism on the susceptibility to OP toxicity on semen quality and DNA integrity in agricultural workers. A cross-sectional study was conducted in farmers with Mayan ascendancy from southeastern Mexico chronically exposed to pesticides; mostly OP. Fifty four agricultural workers (18-55 years old) were included, who provided semen and blood samples. Semen quality was evaluated according to WHO, sperm DNA damage by in situ-nick translation (NT-positive cells), PON1Q192R polymorphism by real-time PCR and serum PON1 activity by using phenylacetate and paraoxon. Two OP exposure indexes were created: at the month of sampling and during 3 months before sampling, representing the exposure to spermatids-spermatozoa and to cells at one spermatogenic cycle, respectively. PON1 192R and 192Q allele frequencies were 0.54 and 0.46, respectively. Significant associations were found between OP exposure at the month of sampling and NT-positive cells and sperm viability in homozygote 192RR subjects, and dose-effect relationships were observed between OP exposure during 3 months before sampling and sperm quality parameters and NT-positive cells in homozygote 192RR farmers. This suggests that cells at all stages of spermatogenesis are target of OP, and that there exists an interaction between OP exposure and PON1Q192R polymorphism on these effects; farmers featuring the 192RR genotype were more susceptible to develop reproductive toxic effects by OP exposure.     

Paraoxonase 1 mutations in a Turkish population.

Human serum paraoxonase 1 (PON1) catalyzes the hydrolysis of certain organophosphate pesticides and nerve gases and so may alter significantly an individual's susceptibility to the toxicity of these chemicals. Moreover, PON1 hydrolyzes lipid peroxides complexed to low density lipoproteins (LDL) and therefore it was suggested that PON1 may be one of the genes that is involved in the pathogenesis of cardiovascular diseases. Its activity shows interindividual and interethnic variability. At least two mutation sites, namely Gln192Arg (Q/R) and Leu55Met (L/M) were reported responsible for the variations in enzyme activity. The aim of the present study was to determine the frequency of these mutations in Turks and compare the results with other European and Oriental populations. A total of 381 unrelated Turkish individuals were genotyped for Gln192Arg and Leu55Met polymorphisms by PCR-RFLP using AlwI and NlaIII, respectively. Genotype distribution was QQ = 0.49, QR = 0.40, RR = 0.11, and LL = 0.52, LM = 0.39, MM = 0.09. Thus frequencies of high activity alleles R (Arg) and L (Leu) were found as 0.31 and 0.72, respectively. The frequency of these alleles was slightly higher in Turkish subjects than other Caucasian populations but much lower compared to Oriental populations.     

Paraoxonase 1 (PON1) status and substrate hydrolysis

Paraoxonase 1 (PON1) hydrolyzes a number of organophosphorus (OP) compounds including insecticides and nerve agents. The in vivo efficacy of PON1 to protect against a specific OP exposure depends on the catalytic efficiency of hydrolysis. The Q192R polymorphism affects the catalytic efficiency of hydrolysis of some substrates and not others. While PON1_R192 hydrolyzes paraoxon approximately 9-times as efficiently as PON1_Q192, the efficiency is insufficient to provide in vivo protection against paraoxon/parathion exposure. The two PON1₁₉₂ alloforms have nearly equivalent but higher catalytic efficiencies for hydrolyzing diazoxon (DZO) and provide equivalent in vivo protection against DZO exposures. On the other hand, PON1_R192 is significantly more efficient in hydrolyzing chlorpyrifos oxon (CPO) than PON1_Q192 and provides better protection against CPO exposure. Thus, for some exposures it is only the level of plasma PON1 that is important, whereas for others it is both plasma level and the PON1₁₉₂ alloform(s) present in plasma that are important. In no case is the plasma level of PON1 unimportant, provided that the catalytic efficiency is sufficient to protect against the exposure. Two-substrate enzyme assay/analysis protocols that reveal both PON1 plasma levels and PON1₁₉₂ phenotype (QQ; QR; RR) are designed to optimize the separation of PON1₁₉₂ phenotypes; however, they have not been optimized for evaluating in vivo rates of OP detoxication. This study describes the adaptation of a non-OP, two-substrate determination of PON1 status to the conversion of the PON1 status data to physiologically relevant rates of DZO and CPO detoxication. Conversion factors were generated for rates of hydrolysis of different substrates.     

Variability of the paraoxonase gene (PON1) in Euro- and Afro-Brazilians

The human high-density lipoprotein-associated paraoxonase (EC 3.1.1.2; PON1) plays a role in the hydrolysis of organophosphorus compounds and against the oxidative damage of low-density lipoprotein. In the present study, variants of PON1 (55 and 192) were investigated by PCR-RFLP and PCR-SSCA in Euro- (N = 101) and Afro-Brazilians (N = 70). The PON1*55 and PON1*192 allele frequencies were significantly different in these ethnic groups (p < 0.05 and p < 0.001, respectively). The genotype frequencies for PON1*55 (LL, LM, and MM) in Euro- and Afro-Brazilians were 33, 56, and 11% and 47, 49, and 4%, respectively. The genotype frequencies for PON1*192 were significantly different in Euro- and Afro-Brazilians (QQ, QR, RR: 48, 42, and 10% and 21, 52, and 27%, respectively; p < 0.001). The haplotype frequency distributions were also significantly different in Euro- (LQ = 30.20%; LR = 30.69%; and MQ = 39.11%) and Afro-Brazilians (LQ = 24.97%; LR = 46.46%; MQ = 22.18%; and MR = 6.39%; p < 0.001). Linkage disequilibrium (D) in relation to the maximum expected value was higher in Euro- (100%) than in Afro-Brazilians (58%). We suggest that the high linkage disequilibrium in Caucasians and Asians characterized by the absence or very low frequency of the MR haplotype is mainly due to genetic drift and possibly also to natural selection favoring the PON1*192Q allele or a variant in linkage disequilibrium with it. This seems to be the first study on the PON1 variability at the DNA level in South American samples and one of the few studies on individuals of mixed African origin.     

CYP2C19 and PON1 polymorphisms regulating clopidogrel bioactivation in Chinese, Malay and Indian subjects

AIM, MATERIALS & METHODS: We investigated the functional significance of CYP2C19*2, *3, *17 and PON1 Q192R SNPs in 89 consecutive Asian patients on clopidogrel treatment and the prevalence of functionally significant polymorphisms among 300 Chinese, Malays and Asian Indians. RESULTS: Both CYP2C19 loss-of-function alleles (*2 or *3) were associated with higher platelet reactivity while the CYP2C19 gain-of-function allele (*17) had lower platelet reactivity. For PON1, the median PRI was not significantly different between the QQ, QR and RR groups. The allele frequencies of CYP2C19*2, CYP2C19*3 and CYP2C19*17 were 0.280, 0.065 and 0.010 (rare) for Chinese, 0.310, 0.050 and 0.025 for Malays, and 0.375, 0.010 (rare) and 0.165 for Indians, respectively. CONCLUSION: Our data suggest that genotyping studies to investigate clopidogrel response should include CYP2C19*2 and *3 but not *17 polymorphisms in Chinese, and CYP2C19*2 and *17 polymorphisms but not *3 in Indians. All three polymorphisms should preferably be genotyped in Malays.     

Association of polymorphisms in low-density lipoprotein receptor-related protein 5 gene with bone mineral density in postmenopausal Chinese women

AIM: To investigate the possible association of Q89R, N740N and A1330V polymorphisms in low-density lipoprotein receptor-related protein 5 (LRP5) gene with bone mineral density (BMD) in postmenopausal Chinese women. METHODS: Q89R, N740N and A1330V genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 647 unrelated healthy postmenopausal Han Chinese women aged 43-76 years in Shanghai. BMD at lumbar spine 1-4 and the left proximal femur including the femoral neck, trochanter and Ward's triangle were measured by dual-energy X-ray absorptionmetry in all subjects. RESULTS: The distribution of the Q89R, N740N and A1330V genotypes in this population was as follows: QQ 80.5%, QR 18.7%, and RR 0.8%; TT 66.9%, TC 31.1%, and CC 2.0%; AA 68.0%, AV 29.7%, and VV 2.3%. The frequencies of the Q89R, N740N and A1330V genotypes and alleles did not deviate from the Hardy-Weinberg equilibrium. We found that the Q89R and A1330V polymorphisms were in linkage disequilibrium in our population (kappa2=13.50, P<0.01). Both before and after adjusting for age, years since menopause, height, and weight, the Q89R or N740N genotypes were significantly associated with BMD at the femoral neck (P<0.05). Subjects with the Q89R QQ genotype or the N740N TT genotype had a significantly higher BMD at the femoral neck, compared with those with the QR/RR or TC/CC genotypes, respectively. No significant association was found between A1330V polymorphism and BMD at any site. CONCLUSION: Our findings suggest that the LRP5 gene is a candidate for the genetic determination of BMD in postmenopausal Chinese women.