非编码RNA在大气细颗粒物致儿童呼吸系统早期损伤中的作用及机制研究

Ambient fine particulate matter (PM2.5) is a major environmental pollutant and raises significant public health concerns all over the world. Several cohort studies have revealed that exposure to ambient PM2.5 is associated with increased lung injury, morbidity and mortality from respiratory disease in children. Non-coding RNA (ncRNA) is one of key factors regulating the occurrence and progression of several diseases. As the sensitive population to PM2.5, there is still very few studies on the role and mechanism of non-coding RNA on early respiratory injury in children exposed to PM2.5. .In the preliminary study, we found the significant changes on lung injury induced by PM2.5 in children. We are going to expand our study cohort. By systematically evaluating the exposure characteristics of PM2.5 and comparing the baselines from our biological monitoring data, we can determine the main harmful components of PM2.5 in our study. From analysis on high-throughput screening for non-coding RNA, validation of biomarker, to adverse outcome pathway (AOP), we can find the candidate ncRNAs indicating early respiratory injuries for children. Then we analyze the stability and effectiveness of candidate ncRNA in two children’s cohorts, with definitive dose-response relationship between PM2.5 exposure and biomarkers of effect. We also evaluate its sensitivity and specificity in asthma cases. Further, we observe the biological effects of ncRNAs in cell models treated by PM2.5, identify the key non-coding RNA molecule, and elucidate its main mechanisms of action during lung injury. .Combined population study with laboratory study, our project can answer the key issue of early identification on adverse effect on children induced by PM2.5 exposure. The hypothesis was clear and original in our study. Outcomes from our project will give crucial evidences for guiding the risk assessment and prevention of respiratory injury in children caused by PM2.5.

大气细颗粒物（PM2.5）是全球范围内广受关注的主要污染物，流行病学队列研究已经证明PM2.5会导致呼吸系统损伤，显著增加呼吸系统疾病的发病率和死亡率。非编码RNA通过调节靶基因的表达，在疾病发生进展过程中发挥重要的调控作用，并在疾病的早期标志物研究中逐渐受到关注。儿童呼吸系统还没有发育完全，自我防御能力较弱，对颗粒物更加敏感。但是，目前还缺乏非编码RNA在PM2.5致儿童呼吸系统早期损伤的作用和机制研究。本研究在已有人群基础上，发现PM2.5致儿童肺损伤的重要改变。通过扩大研究队列，系统评估PM2.5的暴露特征，确定PM2.5的主要有害组分；结合高通量筛选、验证和毒作用路径分析，在多中心人群中分析候选非编码RNA与暴露和效应标志物间的暴露-反应关系，确定标志物的有效性，评估灵敏度和特异度。在体外细胞模型中观察PM2.5主要有害组分的生物学作用，确定关键的非编码RNA分子，并阐明其在肺损伤中的作用机制。本项目结合人群研究与实验室研究，拟解决儿童PM2.5暴露早期健康效应识别的关键问题。研究具有一定的独创性、主要研究结果将为指导PM2.5致儿童呼吸系统早期损伤的风险评估和预防提供重要依据。

大气细颗粒物（PM2.5）是导致儿童呼吸系统损伤的主要污染物，其中富集多环芳烃、重金属等有害组分。既往研究多关注PM2.5对儿童健康影响的流行病学调查，缺少颗粒物有害组分与儿童早期健康损伤的生物标志物研究。本项目主要以寄宿制学校的学生为观察对象，监测发现PM2.5与苯并[a]芘、锰、镍、砷、镉、铅等组分有很强的相关性，体内血清BPDE加合物和尿金属的负荷水平与儿童暴露特征一致，暴露组血清BPDE加合物是对照组的1.27倍。在淋巴细胞亚群、免疫球蛋白和补体分析中，暴露组补体C3、C4降低，血清BPDE加合物与补体C3、C4有剂量-效应关系。研究发现血液表面活性蛋白等可以作为颗粒物致呼吸损伤的标志物；儿童血清BPDE加合物每升高一个IQR，血清CC16升高8.35%；高暴露组的儿童肺功能明显降低，并与血清肺损伤蛋白有一定的相关性。在非编码RNA分析中，暴露组miR-638水平升高，与血清BPDE加合物存在剂量-效应关系。经中介效应分析，let-7a、miR-146a-5p和miR-155-5p介导了BPDE加合物对儿童IL-6和TLR2的表达水平。在miRNA-200家族中，暴露组miR-200a-3p和miR-429表达升高，血清BPDE加合物每改变一个IQR，miR-429升高12.01%；尿中As、Cd与miR-429有良好的暴露反应关系；miR-200b-3p每增加一个IQR，NOTCH-1表达降低9.72%；并发现氧化应激在尿Cu对miR-200a-3p、miR-429影响的中介作用。长链非编码RNA分析中，颗粒物可致儿童MALAT1、GAS5和LINC00341表达下降，并与血清VEGF等因子有较好的相关性。本项目的研究成果将为儿童呼吸系统疾病的早期标志物识别和风险评估提供主要依据。