长链非编码RNA在调控二甲基甲酰胺诱导肝脏毒性中的作用及其机制

Occupational toxic hepatopathy induced by dimethylformamide (DMF) exposure causes adverse health effects on occupational workers in China. The key for disease prevention is to understand the mechanism of poisoning and seek early biomarkers. Long non-coding RNA (lncRNA) belongs to the non-coding RNA family, our previous study found that non-coding RNA is involved in the process of liver injury mediated by some chemicals and can be more sensitive than transaminase to reflect chemicals-induced hepatic damage. However, whether lncRNA can influence the DMF-induced liver toxicity are still unknown. The approach of the dynamic inhalation was applied to establish a mice liver injury model with DMF exposure in this project. Analysis of DMF metabolism, high throughput sequencing and assays of toxic effect biomarkers will be employed to investigate the dynamic change models of lncRNA profiling from DMF exposure to the appearance of hepatic toxicity, and bioinformatics will be used to screen the candidate lncRNAs which are correlated with the DMF exposure or reflect the early toxic effects caused by DMF. With the application of in vitro hepatic cell models, the key molecular targets and toxic pathway regulated by candidate lncRNAs are identified to explore the role of lncRNA in the occurrence of DMF poisoning. Furthermore, the potential of prediction and early diagnosis of DMF-induced liver injury by these lncRNAs will be validated in occupational population who exposed to DMF. This project will help us to understand the feasibility of the lncRNA as an important effect biomarker applied in the risk assessment of DMF exposure.

二甲基甲酰胺（DMF）引起的职业性肝中毒严重危害我国职业工人健康。阐明中毒机制和寻找与DMF中毒相关的早期生物标志对疾病防控至关重要。长链非编码RNA（lncRNA）是ncRNA中的一类，课题组前期研究发现ncRNA介导了某些化学物的肝损伤效应，较转氨酶更灵敏的反映其肝毒性。然而，lncRNA是否参与调控DMF的肝脏毒性则还未见阐述。本项目拟采用动式吸入染毒法，建立DMF暴露小鼠肝损伤模型，通过代谢物分析、高通量测序、毒效应指标检测等手段了解从DMF暴露到出现肝毒效应过程中lncRNA的动态变化并筛查与DMF暴露关联且能早期反映其肝毒性的lncRNA。应用肝细胞模型明确lncRNA作用的关键靶点和毒性通路，揭示其在DMF诱导肝损伤中的分子机制。在职业人群中验证lncRNA作为DMF诱导肝损伤早期生物标志的潜能。本研究结果将揭示lncRNA作为重要生物效应标志应用于DMF危险度评价的可行性。

二甲基甲酰胺（N,N-Dimethylformamide，DMF）是一种广泛应用于工业生产的有机溶剂。DMF对人体毒性最明显的是肝脏毒性，但是DMF对肝脏损伤的作用机制研究尚未明确。本研究才用高通量测序技术探究了非编码RNA在DMF致肝脏毒性中发挥的作用。结果发现：1. DMF暴露能促进ERK蛋白的活化，使维甲酸受体RXRα在胞内堆积而抑制抗氧化相关的核受体因子F2 (NRF2)的转录活性，从而加剧DMF诱导的氧化损伤。2. DMF暴露能诱导肝细胞出现剂量依赖性的凋亡，其机制与其促进微小RNA（miR-192-5p）表达升高，从而抑制抗凋亡相关基因NOB1的表达有关。3.此外，我们的研究还发现 DMF暴露能诱导肝脏细胞中长链非编码RNA（SNHG12）的表达下调，SNHG12通过has-miR-218-5p/PRKCE信号轴参与了调控DMF诱导的肝脏细胞凋亡过程。并且，我们在DMF暴露工人血清外泌体中也检测到SNHG12表达下调，提示SNHG12可以作为新的效应生物标志物用于DMF的生物监测。4. DMF暴露能诱导肝脏细胞中环状RNA（hsa_circ_0005915）的表达上调，hsa_circ_0005915可以促进NRF2的降解，抑制NRF2的转录活性，从而加剧DMF诱导肝细胞氧化损伤。研究结果阐明了DMF致肝脏损伤的调控机制，为将非编码RNAs作为早期生物标志物应用于DMF暴露的生物监测和危险度评价提供了初步的实验证据。课题剩余经费将继续用于本项目研究后续支出。