Hsa_circ_0008668 regulates osteoblast and osteoclast differentiation by targeting miR-140-3p

Objectives As China’s population ages, a dramatic rise in osteoporotic fracture incidence is expected to happen. The current study was designed to determine the expression level and the cellular function of hsa_circ_0008668 during osteoblast and osteoclast differentiation. Methods The GSE159121 and GSE161361 datasets were downloaded and analyzed. Serum samples from patients with osteoporotic fractures were collected to determine the hsa_circ_0008668 levels. The effects of hsa_circ_0008668 on the levels of respective differentiation markers of osteoblasts and osteoclasts were examined by in vitro experiments. Downstream targets of hsa_circ_0008668 were predicted and validated by rescue experiments. Results GSE159121 and GSE161361 datasets identified hsa_circ_0008668 as a downregulated circRNA in cases of osteoporotic fracture. Overexpression of hsa_circ_0008668 in osteoclasts was found to inhibit cell osteoclastic marker levels, while the knockdown of hsa_circ_0008668 in osteoblasts was found to inhibit the expression of osteogenic markers. miR-140-3p was a target of hsa_circ_0008668 and rescued the functions of hsa_circ_0008668 on osteoblast and osteoclast differentiation. Conclusions Hsa_circ_0008668 may be a regulator of osteoblast and osteoclast differentiation by targeting miR-140-3p.