miRNA靶基因（ALAD和PON1）SNPs与职业性铅中毒发生机制的研究

Lead poisoning, as a one of concern for social problems, has a high incidence rate in Chinese occupational population. Previous studies have shown that miRNA plays important roles in the mechanism of lead poisoning; however, no report about miRNA SNPs has been found today. Based on the previous study, we found that some SNPs in 3’-UTR of ALAD and PON1 gene might change the binding of miRNA, sequentially influence the development of lead poisoning, and these two genes were involved in the process of lead poisoning. In this subject, we will first to genotyping the SNPs in 3’-UTR of ALAD and PON1 gene in 1000 lead exposure people; secondly, report gene and miRNA cotransfected experiments will be taken to clarify the role of SNPs in 3’-UTR in the process of lead poisoning; lastly, we will go back to the population to detect the urine ALA, serum PON1, mRNA level of ALAD and PON1, and protein level of ALAD among all kinds of genotype, and this can further verify the function of SNPs in 3’-UTR. In conclusion, this subject will combine the population study and the laboratory investigations. This will help to systemically understand the distribution of miRNA target gene SNPs in Chinese occupational lead poisoning populaton. This subject will be benefit to find the molecular mechanism of lead poisoning from a new light, and to get the biomarkers which are more suitable for Chinese lead poisoning population. The findings will offer important references for the prevention and treatment of lead poisoning.

铅中毒，作为一个备受关注的社会问题之一，在中国职业人群中的发生率一直居高不下。研究显示miRNA在铅中毒的机制中起重要作用，但目前尚无SNPs方面的报道。基于前期的研究结果，铅中毒相关基因ALAD和PON1基因3’-UTR SNPs可影响miRNA结合，从而影响铅中毒发生。本课题中，我们拟在对1000名铅暴露人群ALAD和PON1基因3’-UTR SNPs分型的基础上，进行报告基因与miRNA共转染实验；同时检测人群中不同基因型个体尿ALA和血清PON1水平以及白细胞中ALAD、PON1基因mRNA和蛋白水平，阐明3’-UTR SNPs在铅中毒发生过程中的作用。本课题结合人群研究和实验室研究，可系统地了解中国职业性铅暴露人群miRNA靶基因SNPs的分布情况，并从一个新的角度对铅中毒发生的分子机制进行深入研究，获得适合中国铅中毒人群的生物标志物；同时能够对铅中毒的预防和治疗提供重要参考。

职业和环境中的铅暴露已经成为全世界关注的问题。随着经济的发展，与环境中铅暴露相关的健康风险不断增加。铅中毒在中国职业人群中的发生率一直居高不下。人们对铅毒性的研究已经有几百年的历史，但如何从分子水平对铅中毒进行预防和诊治，还没有一个较好的靶标。研究显示miRNA 在铅中毒的机制中起重要作用，但目前尚无相关的报道。本研究利用生物信息学工具查找了ALAD基因3’UTR区可能的多态性位点，并在人群中验证了这些SNPs与铅中毒发生风险的关系。随后在细胞模型中运用报告基因、RT-PCR、Westen blo等实验对这些SNPs与miRNA的关系进行了深入分析。本研究在病例-对照中发现rs8187098 C等位基因型可以显著降低铅中毒发生危险性；进一步研究发现rs818708 T＞C变异能减弱miR-545-5p 与 ALAD基因3’UTR区结能力，最终能够增加ALAD的表达水平，而这也将改变铅中毒发生的风险。本研究从miRNA 靶基因结合区域SNPs 这一全新的角度入手，在人群分子流行病学病例-对照的基础上，提出假设：ALAD基因3’-UTR 区SNPs 可影响miRNA 结合，从而改变基因mRNA 或蛋白表达水平。本研究从人群出发，结合细胞水平实验，最后回到人群深入分析，全面科学的对我们的假设进行论证，为铅中毒机制的研究提供了新的生物标志物，也为铅中毒的预防和治疗提供重要参考。