COMT基因多态性、血浆蛋白组学与高氟地区儿童智力关系的研究

发布时间：2018-06-09 01:55

本文选题：氟 + 儿童智力水平　；参考：《华中科技大学》2012年硕士论文

【摘要】：氟在环境中广泛存在，人体的暴露途径主要是通过接触食物、水及含氟的牙膏等产品。另外，工业污染和燃煤污染也已成为中国地区氟暴露的主要来源。长期摄入过量氟可引起严重的公共卫生问题即氟中毒（fluorosis）。氟中毒在全球均有发生，且影响达数百万人。氟除对牙齿和骨骼产生毒性效应外，还具有神经毒性。Roholm等发现氟对小鼠中枢神经系统具有毒性作用，使其脊髓神经纤维和小脑的外颗粒层细胞显著减少，神经元凋亡明显增加。而且，氟可导致胎鼠神经元密度和未分化神经元数目发生改变。有研究报道，氟对大鼠行为产生不良效应的严重程度与血清及大脑特定区域中氟离子浓度直接相关。人群流行病学调查表明，生活在氟中毒地区儿童的学习记忆能力和智力水平明显低于生活在正常地区的儿童。某一地区饮水中氟含量在一定时间内是长期不变的。氟一旦被吸收进入血液，容易分布全身。在儿童，大约80-90%氟被保留在体内，其余主要经肾脏排出体外，即氟在24h内由尿排出摄氟量的50-92%。故血清氟浓度和尿氟浓度在一定程度上可作为人体内氟蓄积水平的参考指标。本次调查中，我们利用中国农村联合瑞文测验（CRT-RC）测试儿童智力水平（IQ），氟离子选择电极法测定饮用水、儿童血清和尿液中氟浓度，并探讨血清氟和尿氟浓度与儿童IQ之间的关系。额叶前皮质的多巴胺能调节个体的认知过程、学习记忆能力和控制执行能力。儿茶酚氧甲基移位酶（COMT）是影响多巴胺能神经递质代谢的关键酶，可调节额叶前皮质内至少60%的多巴胺的降解。故个体COMT的活性变化可影响机体多巴胺的代谢过程，从而影响个体的认知、学习过程。COMT基因在第158个密码子存在一个G/A突变，使其编码的氨基酸由缬氨酸（val）变成蛋氨酸（met），同时该酶也变成不耐热的低活性形式。Egan等研究发现COMT基因多态性与儿童认知能力之间具有相关性，但COMT基因多态性与氟中毒地区儿童认知能力的关系目前尚未见报道。有研究显示，甲状腺激素水平可作为检测儿童智力低下的敏感指标。蛋白质作为生命功能的直接执行者，它比基因更能直接的反映生理过程及其变化。因此，我们利用蛋白质组学方法研究氟中毒发生发展过程中某些蛋白或多肽水平的变化，寻找差异表达蛋白，为寻找氟中毒儿童早期生物标志物提供一定依据。第一部分饮水高氟对儿童智力的影响目的：探讨高氟地区儿童血清氟、尿氟和甲状腺激素水平与儿童智力水平的关系。方法：收集儿童饮用水样、尿样和血液样本。利用氟离子选择电极法，放射免疫检测试剂盒和中国农村联合版瑞文测试（CRT-RC）测定饮水氟、儿童尿氟及血清氟浓度、血清甲状腺激素及儿童智力水平。结果：高氟组和对照组儿童之间的饮水氟、尿氟、血清氟浓度、血清TSH水平和IQ得分均存在显著性差异（P 0.05）。Spearman分析显示尿氟、血清氟浓度与儿童IQ得分之间存在负相关关系（rs=-0.206, P 0.01; rs=-0.187, P 0.05）。结论：长期摄入过量氟可影响儿童智力水平。第二部分COMT基因多态性与儿童智力的关系目的：探讨COMTval158met多态性与儿童智力水平的关系。方法：利用限制性片段长度多态性聚合酶链反应（PCR-RFLP）辨别COMT基因多态性与儿童智力水平之间的关系。结果：携带val/val基因型儿童的IQ得分明显高于携带met/val、met/met基因型儿童的水平（P 0.001）。结论：val/val的基因型表达可能对儿童的智力发展有保护作用。第三部分高氟暴露儿童血浆蛋白组学研究目的：检测高氟暴露儿童血浆蛋白表达谱的改变以及相关蛋白的鉴定。方法：高氟组10名儿童，对照组10名儿童。利用2-DE和Autoflex speed MALDI-TOF-TOF技术对两组儿童血浆蛋白进行分离鉴定。结果：与对照组相比，在高氟组发现7个表达不同的蛋白点，经质谱共鉴定出5种表达上调的蛋白，，包括补体CIs亚单位前体、α-1-B糖蛋白、血红素结合蛋白、载脂蛋白E前体以及免疫球蛋白轻链变异区域。结论：氟中毒儿童血浆蛋白表达谱发生改变，为寻找氟中毒儿童的早期生物标志物提供了一定基础。
[Abstract]:In addition , industrial pollution and coal pollution have become the main source of fluoride exposure in China . In addition , industrial pollution and coal pollution have become the main source of fluoride exposure in China .

In this study , the concentration of fluorine and fluoride in drinking water , serum and urine of children were measured by using Chinese rural joint Swedish test ( CRT - RC ) , and the relationship between serum fluorine and urine fluoride concentration and IQ was discussed .

There is a G / A mutation at codon 158 of the COMT gene , which can affect the cognitive and learning process of the individual . The COMT gene has a correlation between the polymorphism of COMT gene and the cognitive ability of children .

It is shown that thyroid hormone level can be used as a sensitive index to detect children ' s mental retardation . Protein as the direct executor of the function of life reflects the physiological process and its changes more directly than the gene . Therefore , we study the changes of some proteins or polypeptide levels in the course of development of fluorosis by using the proteomic method , find out the differential expression protein , and provide some basis for finding the early biomarkers of fluorosis children .

The Effect of Drinking High Fluorine on the Intelligence of Children in Part I

Objective : To investigate the relationship between serum fluorine , urinary fluoride and thyroid hormone levels in children with high fluorine content and children ' s intelligence level .

Methods : Children ' s drinking water samples , urine samples and blood samples were collected . Use of fluoride ion selective electrode method , radioimmunoassay kit and Chinese rural joint version of Swedish test ( CRT - RC ) were used to determine the levels of fluoride in drinking water , urine fluoride of children and serum fluorine concentration , serum thyroid hormones and children ' s intelligence .

Results : The levels of fluoride , fluoride , serum fluorine , serum TSH and IQ scores between high fluoride group and control group were significantly different ( P 0.05 ) . The results showed that there was a negative correlation between urinary fluoride , serum fluorine concentration and IQ scores in children ( rs = - 0.206 , P 0.01 ; rs = - 0.187 , P 0.05 ) .

Conclusion : Long - term intake of excess fluoride can affect children ' s intelligence level .

The Relationship between the Polymorphism of the Second Part COMT Gene and the Intelligence of Children

Objective : To investigate the relationship between the polymorphism of COMTval158 met and the level of intelligence of children .

Methods : Using restriction fragment length polymorphism polymerase chain reaction ( PCR - RFLP ) to identify the relationship between COMT gene polymorphism and intelligence level of children .

Results : The IQ scores of children with val / val genotype were significantly higher than those with met / val and met / met genotypes ( P 0.001 ) .

Conclusion : The genotype expression of val / val may play a protective role in the intelligence development of children .

Study on Plasma Proteomics of the Third Part of High Fluorine Exposure Children

Objective : To detect the changes of plasma protein expression profile and the identification of related proteins in children exposed to high fluorine exposure .

Methods : 10 children in high fluorine group and 10 children in control group were separated and identified by 2 - DE and Autoflex speed MALDI - TOF - TOF technique .

Results : Compared with the control group , 7 expressed different protein spots were found in the high fluoride group . Five of the up - regulated proteins were identified by mass spectrometry , including complement , subunit precursor , 伪 - 1 - B glycoprotein , heme binding protein , apolipoprotein E precursor and immunoglobulin light chain variable region .

Conclusion : The expression profile of plasma protein in children with fluorosis is changed , which provides a basis for finding the early biomarkers of fluorosis children .
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R599.1

【参考文献】