Calcitonin gene-related peptide induces IL-6 expression in RAW264.7 macrophages mediated by mmu_circRNA_007893

Several circular RNAs (circRNAs) may have role important roles in biological processes, however, there is limited knowledge of circRNAs and their potential functions in RAW264.7 macrophages. The present study aimed to examine the expression of circRNAs and explore their effects on interleukin-6 (IL-6) expression induced by calcitonin gene-related peptide (CGRP) in RAW264.7 macrophages. To identify circRNAs, the circRNA expression was measured in macrophages with or without CGRP stimulation. The interaction between circRNAs and microRNAs (miRs) were then identified using bioinformatic software and networks. In the current study, it was demonstrated that CGRP increased the expression of IL-6 mRNA in a dose- and time-dependent manner. Furthermore, mmu_circRNA_007893 was significantly increased in the CGRP-stimulated macrophages. Silencing of mmu_circRNA_007893, IL-6 mRNA expression was significantly decreased, whereas mmu-miR-485-5p expression was markedly increased. Furthermore, when overexpression of mmu-miR-485-5p, IL-6 mRNA was markedly decreased. The results demonstrated that CGRP-induced IL-6 mRNA expression was mediated by mmu_circRNA_007893, and mmu_circRNA_007893 functioned as an endogenous mmu-miR-485-5p sponge as part of induction of IL-6 mRNA expression.