[Differential on N6-methyladenosine modification of circRNA in early inflammation of silicosis]

Objective: To explore the difference of methylation of circRNA related m6A in early inflammation of silicosis and to elucidate the underlying molecular mechanism of circRNA involved in the process of silicosis. Methods: The activation markers of macrophages were detected by Western blotting (WB) in THP-1-derived macrophages. The cell viability was detected with CCK8, by which the stimulation concentration and time of silica were determined. The methylation of total RNA was determined by colorimetry, and the expression of RNA m6A methylase, demethylase and reading protein were detected by Western blotting in mouse model of silicosis. The differential expression of m6A modified circRNA in lung tissues form silicosis and control mice was obtained through Arraystar m6A circRNA epigenetic transcriptome Chip and verified by RT-PCR. Results: The concentration of SiO(2) at 50 μg/cm(2) had the most significant effect on the activation markers and activity of macrophages. Compared with the control group, SiO(2) increased the total RNA m6A level of macrophages, and there were significant differences in the expression of methylase METTL3 and reading protein YTDHF3. High throughput sequencing analysis showed that compared with the control group, the methylation levels of 132 circRNA m6A in the lung of silicosis model mice were increased, while the methylation levels of 296 circRNA m6A were decreased, and then the target circSLC2A13 was screened based on the basic expression. Further verification showed that SiO(2) significantly increased the expression of circSLC2A13 and m6A modification in macrophages. Conclusion: The methylation of circRNA m6A is involved in the activation of macrophages in early inflammation of silicosis.