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Circular RNAs (circRNAs) are a class of non‑coding RNAs that exhibit important regulatory roles in various biological processes. However, the role of circRNAs and their potential role in osteoblast differentiation and mineralization is unclear. The aim of the present study was to investigate the expression of mmu_circ_003795 and its effect on collagen type XV α 1 chain (COL15A1). First, it was identified that the expression levels of mmu_circ_003795 and osteopontin (OPN) were upregulated in the induced cells. Silencing of mmu_circ_003795 reduced the gene and protein levels of COL15A1 and OPN, whereas the expression level of mmu‑microRNA (miR)‑1249‑5p was upregulated. In addition, after 7 or 14 days of induction, alkaline phosphatase and Alizarin Red‑S staining were decreased in the mmu_circRNA_003795 inhibitory group compared with the negative control group. In conclusion, mmu_circ_003795 may regulate osteoblast differentiation and mineralization in MC3T3‑E1 and MDPC23 cells via mmu‑miR‑1249‑5p by targeting COL15A1.

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.