饮水型砷暴露致广泛性焦虑效应及血浆外泌体特异miRNA的研究

The epidemic situation of arsenic poisoning in Bayannaoer city of Inner Mongolia was serious, due to the geographical and economic conditions, the arsenic level of water was still high after conducting the concentration drop of arsenic, and affected a large amount of people. The arsenic accumulated in the body, and through the blood brain barrier, cause damage of nervous system. Our previous studies have found that in 2663 arseniasis, 1423 cases combined nervous system symptoms. Our team conducted a survey in bayinnaoer city recently, suggested that the rate of the GAD was 28.3% in high arsenic water area, higher than the general population, so the hypothesis is: wheather the GAD is associated with arsenic exposure? Very few studies on this aspect has been reported so far. This project intends to conduct research on this issue with there stages. (1) Patients with GAD as cases, match with non-GAD as a control, measure the arsenic levels in urinary, analysis of the relationship between arsenic exposure and the GAD. (2) Using deep sequencing, detect the miRNA expression differences in plasma exosomes within the high arsenic water exposed the GAD group, the high arsenic water exposed the non-GAD group, non-GAD without high arsenic water exposure group, and find out the specific MicroRNAs, conduct bioinformatics analysis, propose possible mechanism of arsenic exposure to GAD. (3) Conducting animal experiments to verify the exosome specific miRNA in plasma of the GAD caused by arsenic.

内蒙古巴彦淖尔地区地方性砷中毒疫情严重，由于地域和经济条件限制，集中降砷改水后，仍有水源砷浓度严重超标，且受累人数众多。砷在体内蓄积，且可通过血脑屏障，造成神经系统损害。我们前期研究的2663名砷中毒病例中有1423例合并神经系统症状，团队近期于巴彦淖尔市开展的调查提示，高砷水地区群众广泛性焦虑（GAD）患病率28.3%，高于一般人群，由此提出GAD是否与砷暴露有关？目前基于这方面的研究鲜见报道。本项目拟分三个阶段开展研究。（1）GAD患者作为病例组，匹配未患GAD者作为对照组，测量尿砷水平，分析砷暴露与GAD关系；（2）采用高通量测序，检测高砷水暴露GAD组、高砷水暴露非GAD组、非高砷水暴露非GAD组三组人群血浆外泌体miRNA表达谱的差异，找出特异miRNA，进行生物信息学分析，提出砷暴露致GAD可能的机制。（3）动物实验验证砷暴露致GAD的血浆外泌体特异miRNA。

砷在体内蓄积，且可通过血脑屏障，造成神经系统损害。我们前期于巴彦淖尔市开展的调查提示，高砷水地区群众广泛性焦虑（GAD）患病率高于一般人群，由此提出GAD是否与砷暴露有关？我们首先开展了人群研究，发现饮用水中砷含量超标的人群易患轻度GAD、砷中毒者患GAD的风险高、砷相关的神经系统症状与GAD有关系。接下来我们采用高砷（100μg/L）、中砷（50μg/L）水喂养大鼠，检测到了染毒组大鼠的GAD样行为，并且与水砷浓度存在剂量-反应关系，通过对血浆外泌体微小RNA（microRNA, miR）进行测序，显示miR-218a-5p、miR-676、miR-9a-5p、miR-149-5P等在高砷组高表达，采用实时荧光定量PCR进行了验证，结果显示miR-218a-5p、miR-676在两组差异具有统计学意义。为了明确这些miRNAs与GAD的关系，我们采用不确定空瓶刺激建立了广泛性焦虑模型，筛选出了差异miRNAs，与高砷引起表达升高的miRNAs取交集，通过PCR验证，发现miR-218a-5p、miR-676是共同差异的miRNAs。通过生物信息学预测我们发现他们可能通过调NF-kappa B信号通路、PI3K-Akt信号通路、mTOR等信号通路，通过调控炎症、细胞凋亡等参与GAD的发生。总而言之，我们的研究揭示砷暴露增加GAD的风险，应及时采取措施进行预防和干预。外泌体miR-218a-5p、miR-676可能是砷作用的关键分子，进一步对其作用机制进行深入研究，可能为GAD的预防提供科学依据。