维生素D受体基因多态性与铅的肾脏毒性

血铅水平的变化,除了环境等接触因素外,机体的易感性也是铅毒性作用的重要因素,现已发现,在铅负荷、对铅毒性的敏感性等方面均存在着种族差异,提示对铅毒性易感性的不同可能是由于某些遗传因素所致。肾脏在铅代谢、排泄及解毒过程中起着重要的作用,也更易受到损伤。鉴于以上两点,与肾脏有着密切关系的维生素D受体(vitam in D receptor,VDR)基因多态性近年来成为铅毒性作用的研究焦点之一,本文拟就此作一综述。1 VDR与VDR基因多态性1·1 VDR的结构与功能人的VDR是由427个氨基酸组成的酸性蛋白,相对分子质量50 000~60 000,从氨基端到羧…     

ALAD基因多态性对铅的肾脏毒性易感性作用

目的探讨δ-氨基-γ-酮戊酸脱水酶(ALAD)基因多态性是否对铅肾脏毒性易感性产生影响。方法抽取某钢铁企业的142名男性铅接触炉前工作为研究对象,收集基本信息,采集外周静脉血,检测血铅及相关指标、肾功能指标(血清肌酐、肌酐清除率、血尿素氮、和氨基-乙酰-β-葡萄糖苷酶),同时采用实时定量-聚合酶链反应(RT-PCR)进行ALAD基因型测定,估计累积铅暴露,进行ALAD基因多态性与肾脏损害易感性分析。结果 142名铅接触工人中ALAD1-1基因型有120人(84.51%),ALAD1-2基因型有22人(15.49%),未发现ALAD2-2基因型。等位基因ALAD-1和ALAD-2的频率分别为92.25%和7.75%。ALAD1-2基因型组血铅水平和肌酐清除率分别高于ALAD1-1基因型组的个体,差异有统计学意义(均有P<0.05),ALAD1-2基因型组平均血清肌酐低于ALAD1-1基因型组,差异有统计学意义(P<0.05)。低累积铅暴露时,肌酐清除率随着暴露剂量的增加而升高;但高累积铅暴露时,肌酐清除率随着暴露剂量的增加而下降,而且ALAD1-2基因型个体随着暴露剂量的增加下降更为明显。结论在相同铅暴露情况下,ALAD1-2基因引起血铅升高,进而可能影响血清肌酐和肌酐清除率,而这种作用在累积铅暴露达到一定高的阈值时才显示出来,说明ALAD1-2基因多态性会增加铅慢性肾功能损害的易感性风险。     

铅暴露遗传易感性基因研究进展

铅暴露的情况存在于许多企业中,如电子厂、蓄电池厂、冶炼厂、电子垃圾回收厂等。在相同的铅暴露水平上,不同的人群有不同的生物学效应。这在很大程度上取决于人群的遗传易感性。通过铅暴露场所的流行病学调查,运用血尿铅检测、外周血彗星实验、微核实验等方法可以研究铅暴露人群的健康效应与遗传易感性之间的关系,该文介绍了铅遗传易感性基因[δ-氨基-γ-酮戊酸脱水酶(δ-ALAD)基因、维生素D受体基因(VDR)、血色素沉着病基因(HFE)等]与铅暴露的关系,以及铅暴露对发育相关基因(Cbfα1、Brn-3α、Oct-2等)的影响,提出应对铅暴露人群加强易感基因的筛查,保护易感人群健康。     

维生素D受体基因Bsm1多态性与铅暴露儿童的血铅、锌原卟啉和体格发育指标的关系

在 476名严重环境铅暴露儿童中 ,研究了维生素D受体基因Bsm1位点多态性对血铅、锌原卟啉、头围、身高和体重等指标的影响。使用协方差分析校正了年龄、性别、父母文化程度和血铅等影响因素后 ,具有B等位基因儿童的头围明显大于bb基因型个体 (P =0 0 2 ) ;分层分析发现在高血铅组和男性组中Bsm1多态性明显影响头围 (P <0 0 5)。未发现Bsm1位点多态性对血铅、锌原卟啉、身高和体重的明显影响。结果表明 ,VDR基因Bsm1位点的遗传变异可修饰严重铅暴露条件下铅对儿童颅骨发育的影响。     

维生素D受体基因和血色素沉着症缺陷蛋白基因与铅中毒的遗传易感性

铅中毒是危害人类健康的一个严重的公共卫生问题。铅作为一种自然界普遍存在的重金属毒物 ,可造成机体多系统损伤 ,尤其儿童对铅中毒更为敏感。流行病学资料表明 ,在相同的环境铅暴露下个体对铅的毒性反应有明显差异 ,即易感性不同。随着分子生物学技术在环境毒理学方面的应用 ,已证实了一些对环境毒物易感的基因。对铅中毒易感性基因研究较多的是δ 氨基 γ 酮戊酸脱水酶 (ＡＬＡＤ)基因、维生素Ｄ受体 (ＶＤＲ)基因和血色素沉着症 (ＨＦＥ)基因 ,其中已证实ＡＬＡＤ的基因多态性在铅的吸收和生物蓄积方面发挥重要作用[1] 。ＶＤＲ基因调…     

δ-氨基-γ-酮戊酸脱水酶和维生素D受体基因多态性与铅肾毒性易感性的相关研究

目的探讨δ-氨基-γ-酮戊酸脱水酶(ALAD)和维生素D受体(VDR)基因多态性以及基因-基因、基因-环境之间的联合作用对铅肾毒性的作用。方法选择233名铅作业工人,根据工人接触铅水平是否超过职业接触限值将其分为两组,分别测定血铅、尿N-乙酰-β-D-氨基葡萄糖苷酶(NAG)、尿β2-微球蛋白(β2-MG)和尿肌酐,全血提取DAN基因组,多聚酶链反应-限制性片段长度多态性(PCR-RFLP)法分析ALAD和VDR基因多态性。结果超职业限值组,ALAD1-2/2-2基因型和ALAD1-1基因型工人尿NAG的浓度分别为(2.12±0.07)U/mmol Cr和(1.73±0.03)U/mmol Cr,差异具有显著性P<0.05;VDR-Bb基因型的工人尿β2-MG浓度[(20.94±0.12)μg/mmol Cr]高于携带VDR-bb基因型工人的尿β2-MG浓度[(15.28±0.09)μg/mmol Cr](P=0.01)。多因素Logistic回归分析发现,铅接触、高血铅等环境因素以及环境-基因的联合作用都是铅作业工人肾损害的危险因素,接铅水平、血铅水平、ALAD基因型和接铅水平的联合作用引起尿NAG异常的OR值分别为6.85(2.51～10.87)、2.41(1.70～3.41)、3.01(1.10～8.19)。结论在高铅浓度接触下ALAD和VDR基因型与铅肾毒性有关,ALAD-2等位基因和高铅接触是加重铅肾毒性的危险因素。     

辽宁地区汉族人群多巴胺D2受体基因启动子区-241A/G的多态性研究

目的探讨辽宁地区汉族人群多巴胺D2受体(dopamine D2 receptor,DRD2)基因启动子区-241A/G多态性位点的基因型及等位基因的频率分布。方法用等位基因特异性扩增技术对101名辽宁地区汉族人的DRD2基因启动子区-241A/G多态性进行了检测,并与其他人群做比较。结果 (1)DRD2基因启动子区-241A/G的等位基因频率分别为49%和51%,均符合Hardy-Weinberg平衡定律。(2)中国人群与其他人群基因多态性分布频率对照研究发现,DRD2基因启动子区-241A/G多态性分布存在显著性差异。结论 DRD2基因启动子区-241A/G多态性分布具有种族差异。     

重度铅污染地区儿童铅中毒的分子流行病学研究

目的：研究高暴露于铅的条件下，δ－氨基乙酰丙酸脱水酶（ALAD）和维生素D体（VDR）基因多态性对儿童铅中毒易感性的影响。方法：分析了469名严重铅暴露儿童ALAD和VDR基因多态性，血铅、锌原卟啉（ZPP）、头围、身高和体重等指标。结果：具有ALADS等位基因个体，血中ZPP水平高于不含该等位基因的个体（P＝0．017）；携带VDR B等位基因个体的头围大于仅携带b等位基因者（51.19cm和50.75cm）（P＝0．028）。结论：在高水平铅暴露儿童中，ALAD多态性可影响铅的血液毒性效应。VDR基因的遗传变异改变铅对儿童颅骨发育的作用程度。ALAD和VDR基因多态性是影响严重铅暴露条件下儿童铅中毒易感性的分子遗传学因素。     

VDR基因多态性与常见儿童疾病的研究进展

维生素D(vitamin D,VD)也被称为骨化醇,是一种脂溶性固醇类衍生物,属于类固醇激素。维生素D受体（vitamin D receptor,VDR）是一种亲核蛋白,是介导VD的活性代谢产物1,25(OH)D发挥生物效应的核内生物大分子,在调节机体钙磷代谢、组织细胞损伤修复、氧化应激、炎症反应、免疫系统的调节和其他生物过程中发挥着重要作用。近年来,VDR基因的单核苷酸多态性（single nucleotide polymorphism,SNPs）与疾病之间的关联成为热门话题,本文回顾了VDR基因多态性与常见儿童疾病的相关性,对现有的研究结果作一综述。     

维生素D受体基因多态性及维生素D水平与神经发育障碍关系的研究进展

维生素D及其受体在人体不同区域有广泛表达，后者介导活性维生素D的所有分子功能，其基因多态性已被证实与多种发育障碍类疾病易感性相关。现对维生素D受体基因多态性及维生素D水平与神经发育障碍关系的研究进行综述，以期为患儿临床早期预防、干预和治疗提供理论参考。     

维生素D受体基因(VDR)多态性与儿童铅中毒易感性的研究

目的:观察维生素D受体(VDR)基因rs731236、rs1544410及rs7975232在深圳市儿童血铅≥60μg/L样本组和低铅对照组之间的分布,揭示VDR基因多态性与儿童铅中毒易感的相关性。方法:在6个月～6岁儿童中筛选出75例样本组(血铅≥60μg/L均值(X=82.24μg/L)和80例对照组(血铅均值X=19.90μg/L)的样本,用PCR方法对VDR基因rs731236、rs1544410及rs7975232进行扩增,采用基质辅助激光解吸电离飞行时间质谱分析法(MALDI-TOF-MS)鉴定其基因型,比较各基因型在两组间的分布,寻找其与儿童血铅值的关系。结果:VDR基因rs731236中的基因型TT在样本组与对照组的分布频率差异有统计学意义(P<0.05),rs1544410中的GG在样本组与对照组的分布频率差异有统计学意义(P<0.01),rs7975232多态性在样本组与对照组的分布频率差异无统计学意义(P>0.05)。结论:VDR基因rs731236中的TT和rs1544410中的GG基因型可能增加儿童铅中毒的危险性;作为铅中毒的易感基因筛查值得进一步探讨。     

Investigations of vitamin D receptor polymorphism affecting workers' susceptibility to lead

Gene polymorphism is an important factor that affects human susceptibility to toxins. For example, previous studies suggested that the ALAD genotype is an important factor affecting workers' susceptibility to lead toxic effects, including hemopoietic and nervous system. But we have had few researches in Taiwan, though there are thousands of workers involved in lead-related industries. On the other hand, although it is well known that lead deposits in the bone mineral component and interacts with calcium, vitamin D receptor may therefore be an important factor in the metabolism of lead. Some studies suggested that different vitamin D receptor genotypes have various kinds of receptor activity. The goal of this study was to investigate the polymorphism affecting workers' susceptibility to lead. Three allelic variants of the VDR gene were defined by means of the polymerase chain reaction (PCR) and three restriction enzymes (ApaI, BsmI, and TaqI). We determined the relationships of different VDR genotypes (AA, Aa, aa, BB, Bb, bb, TT, Tt, and tt) to blood lead and the index of cumulative blood lead levels (ICL). Altogether we analyzed 544 workers' VDR genotypes (BsmI, TaqI, and ApaI) and compared to their blood lead levels and ICL in the VDR genotypes. The results showed that workers had higher blood lead levels and ICL in the Apa I- aa genotypes, but this is not statistically significant when adjusted for potential confounding factors. Other characteristics, such as exposure status, smoking and alcohol drinking, were significantly associated with ICL and time-weighted ICL. Regression analyses suggested that exposure status and personal habits (smoking and alcohol drinking) are still the major effects on blood lead parameters for lead workers rather than genotypes. In conclusion, VDR genotypes did not significantly affect the long term blood lead parameters after adjustment for all factors, but industrial hygiene improvement, including engineering control and health education, are the most important ways to protect workers' health.     

Vitamin D receptor Fok1 polymorphism and blood lead concentration in children

Variation in blood lead concentration is caused by a complex interaction of environmental, social, nutritional, and genetic factors. We evaluated the association between blood lead concentration and a vitamin D receptor (VDR) gene polymorphism. Environmental samples and blood were analyzed for lead, nutritional and behavioral factors were assessed, and VDR -Fok1 genotype was determined in 245 children. We found a significant interaction between floor dust lead and genotype on blood lead concentration. For every 1 microg/ft(2) increase in floor dust, children with VDR -FF genotype had a 1.1% increase in blood lead [95% confidence interval (CI), 0.69-1.5], VDR -Ff, 0.53% increase (95% CI, 0.1-0.92), and VDR -ff, 3.8% increase (95% CI, 1.2-6.3); however, at floor dust levels < 10 microg/ft(2), children with VDR -ff had the lowest blood lead concentrations. These data suggest that VDR -Fok1 is an effect modifier of the relationship of floor dust lead exposure and blood lead concentration.     

维生素D受体基因多态性与血铅水平的Meta分析

[目的]系统研究维生素D受体基因多态性与血铅水平的关系。[方法]通过数据库检索1990～2007年国内外生物医学期刊发表的有关铅与VDR基因多态性关联性研究的相关文献,用Meta分析软件Revman4.2进行分析。[结果]VDR-Bb/BB基因型的血铅水平高于VDR-bb基因型的血铅水平,有统计学意义(Z=2.66,P=0.008)。[结论]VDR基因型可能是导致铅易感的因素之一。     

Amyotrophic lateral sclerosis,lead, and genetic susceptibility: polymorphisms in the delta-aminolevulinic acid dehydratase and vitamin D receptor genes

Previous studies have suggested that lead exposure may be associated with increased risk of amyotrophic lateral sclerosis (ALS). Polymorphisms in the genes for delta-aminolevulinic acid dehydratase (ALAD) and the vitamin D receptor (VDR) may affect susceptibility to lead exposure. We used data from a case-control study conducted in New England from 1993 to 1996 to evaluate the relationship of ALS to polymorphisms in ALAD and VDR and the effect of these polymorphisms on the association of ALS with lead exposure. The ALAD 2 allele (177G to C; K59N) was associated with decreased lead levels in both patella and tibia, although not in blood, and with an imprecise increase in ALS risk [odds ratio (OR) = 1.9; 95% confidence interval (95% CI), 0.60-6.3]. We found a previously unreported polymorphism in ALAD at an Msp1 site in intron 2 (IVS2+299G>A) that was associated with decreased bone lead levels and with an imprecise decrease in ALS risk (OR = 0.35; 95% CI, 0.10-1.2). The VDR B allele was not associated with lead levels or ALS risk. Our ability to observe effects of genotype on associations of ALS with occupational exposure to lead or with blood or bone lead levels was limited. These findings suggest that genetic susceptibility conferred by polymorphisms in ALAD may affect ALS risk, possibly through a mechanism related to internal lead exposure.     

维生素D受体基因与骨量的关系

近年来对维生素D受体(VDR)基因和骨量关系的研究颇有争议。有许多研究认为维生素D受体基因多态性与骨量有关联。但还有一部分研究未能证实VDR基因多态性与骨量的关联。本文就VDR基因与钙吸收、骨量、药物治疗的关系和VDR基因的协同作用以及与其它基因、环境因素的交互作用对骨量影响的研究进展进行了综述。     

孕妇铅镉锰暴露及金属硫蛋白基因多态性与新生儿出生缺陷的关系

目的 探讨铅镉锰暴露及金属硫蛋白基因多态性与新生儿出生缺陷的关系，为出生缺陷的防治以及制定干预措施提供参考依据。方法 本研究采用巢式病例对照研究方法，从广西壮族人群出生队列中选取广西壮族人群聚居的平果、田东、德保、靖西、隆安等县的人民医院及妇幼保健院2015年9月 - 2018年4月期间纳入队列的孕妇作为研究对象。随访收集一般人口学资料、孕期产检资料、出生结局资料等。采用原子吸收分光光度计（石墨炉法）测定孕妇血浆中铅、镉、锰的含量，采用PCR - RFLP法检测金属硫蛋白基因单核苷酸多态性位点。采用多因素logistic回归模型分析孕妇血浆中铅、镉、锰暴露与金属硫蛋白基因多态性与出生缺陷的关系。结果 多因素logistic回归分析显示:孕妇血镉值升高（OR = 1.93,95%CI:1.11～3.36，P＜0.05）、血锰值升高（OR = 1.22,95%CI:1.12～1.34，P＜0.01）、携带MT - 2A rs10636位点突变型基因型（OR = 3.96,95%CI:1.02～15.39，P＜0.05）是出生缺陷发生的危险因素。金属暴露 - 基因多态性交互作用分析结果显示，孕妇锰暴露与MT - 2A rs10636在出生缺陷发生中存在交互作用。结论 镉、锰高暴露、携带MT - 2A rs10636位点突变型基因型可能是出生缺陷发生的危险因素。     

Influence of the delta-aminolevulinic acid dehydratase (ALAD) polymorphism on biomarkers of lead exposure in Turkish storage battery manufacturing workers

BACKGROUND: The relationship between delta-aminolevulinic acid dehydratase polymorphism (ALAD) and biomarkers of exposure was investigated in Turkish lead workers in this study. METHODS: Seventy two male lead battery manufacturing workers were selected for the study. Blood lead (BPb) and urinary lead (UPb) concentrations were determined by atomic absorption spectrometry. Erythrocyte ALAD activity and urinary 5-aminolevulinic acid (UALA) were measured spectrophotometrically. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to determine the genotype of the ALAD gene. RESULTS: In total, 51 workers (70.8%) had the ALAD 1-1 genotype, whereas 21 workers (29.2%) had the ALAD 1-2 genotype. No significant relationships were found between the two genotypes and BPb, UPb, and ALAD activity. ALAD1 homozygotes showed significantly higher levels of UALA in comparison with those ALAD2 carriers. CONCLUSIONS: ALAD 1-1 individuals might be an increased risk compared to ALAD2 carriers to disturbance in heme biosynthetic pathway in high lead exposure.