摘要目的:探索碳黑纳米颗粒（CBNPs）对人支气管上皮细胞（16HBE细胞）的毒性效应，并根据全转录组高通量测序对差异表达的环状RNA进行筛选与鉴定，为CBNPs暴露的生物标志物研发与其在表观遗传毒理学的应用提供依据。方法:于2020年6月，用20、40和80 μg/ml浓度的CBNPs对16 HBE细胞进行染毒处理，以不加任何干预的16HBE细胞作为对照组，通过CCK8与乳酸脱氢酶（LDH）实验检测CBNPs细胞毒性。实时荧光定量PCR（qRT-PCR）及ELISA法检测各浓度CBNPs染毒72 h后白细胞介素-6（IL-6）和白细胞介素-8（IL-8）mRNA及蛋白水平改变，Western blot检测核因子-κB（NF-κB）相关炎性蛋白[Toll样受体4（TLR4）、磷酸化核因子-κB（P-NF-κB）、凋亡相关斑点样蛋白（ASC）和天冬氨酸蛋白水解酶1（Caspase-1）]的表达水平；根据高通量测序结果筛选并通过qRT-PCR鉴定差异表达的circRNA，选择稳定差异表达且与NF-κB通路关联性最强的circRNA进行环状性能鉴定。结果:与对照组比较，40、80 μg/ml CBNPs暴露72 h后16HBE细胞细胞活力明显下降，20、40、80 μg/ml CBNPs暴露72 h后16HBE细胞LDH释放量明显上升（ P<0.05）。与对照组比较，不同浓度CBNPs暴露72 h后16HBE细胞IL-6、IL-8 mRNA表达水平均增加，IL-6、IL-8蛋白水平均增高，TLR4、P-NF-κB、ASC、Caspase-1蛋白水平均明显上调，差异均有统计学意义（ P<0.05）。与对照组比较，共有492个差异性表达的环状RNA（|log 2 FC|>1），在验证出的5个差异表达（ P<0.05）的环状RNA中，选择circ_002642作为后续环状RNA研究对象，80 μg/ml CBNPs暴露72 h后16HB细胞的circ_002642明显高表达（ P<0.05）。 结论:CBNPs可引起16HBE细胞炎症反应并诱导炎症反应环状RNA的差异性表达。

abstractsObjective:To explore the toxic effect of carbon black nanoparticles on human bronchial epithelial cells, and identify the differentially expressed circular RNA based on the full transcriptome high-throughput sequencing, so as to provide evidence for the development of biomarkers exposed to carbon black nanoparticles and their application on epigenetic toxicology.Methods:In June 2020, 16 HBE cells were treated with carbon black nanoparticles at concentrations of 20, 40 and 80 μg/ml, and 16 HBE cells without any intervention were used as the control group. The cytotoxicity of carbon black nanoparticles was detected by CCK8 and LDH experiments. Real-time quantitative fluorescent PCR (qRT-PCR) and ELISA were used to detect the changes of interleukin-6 (IL-6) and interleukin-8 (IL-6, IL-8) mRNA and protein levels of carbon black nanoparticles with concentration gradient after 72 h exposure. Western blot analysis was conducted to detect the expression levels of toll-like receptor 4 (TLR4), phosphorylated nuclear factor-κB (P-NF-κB), apoptosis-related speckled protein (ASC) and Caspase-1 associated with nuclear factor-κB. According to high-throughput sequencing results, differentially expressed Circrnas were screened and identified by qRT-PCR, and those with stable differentially expressed circrnas and the strongest association with the NF-κB pathway were selected for ring performance identification.Results:After being exposed to carbon black nanoparticles for 72 h, the activity of 16HBE cells decreased significantly ( P<0.05), and the release of lactate dehydrogenase increased significantly ( P<0.05). Compared with control group, mRNA expression levels of IL-6 and IL-8, protein levels of IL-6 and IL-8 were increased, and protein levels of TLR4, p-NF-κB, ASC and Caspase-1 were significantly up-regulated in 16 HBE cells of different concentrations, with statistical significance ( P<0.05). Compared with the control group, a total of 492 differentially expressed circular Rnas (|log2 FC|>1) were detected. Among the 5 differentially expressed ( P<0.05) circular Rnas, circ_002642 was selected as the object of subsequent research on circular Rnas, affter 72 hours of exposure to 80 μg/ml CBNPs, 16HBE cells showed signlficantly higher expression of circ_002642 ( P<0.05) . Conclusion:Carbon black nanoparticles can induce differentially expressed circular RNAs associated with inflammatory response in human bronchial epithelial cells.