MiR-486-3p promotes osteogenic differentiation of BMSCs by targeting CTNNBIP1 and activating Wnt/β-catenin pathway

Abstract Background Dysfunction in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) leads to bone loss/osteoporosis. CTNNBIP1 (Catenin beta interacting protein 1) is an inhibitor of Wnt/β-catenin signaling, whose role in osteogenesis remains elusive. This study aims to reveal the effects of miR-486-3p/CTNNBIP1 in osteogenesis. Methods Bone marrow samples from control and osteoporosis patients were collected and ovariectomy was performed on mice and levels of CTNNBIP1 and miR-486-3p levels were assessed. Dual-luciferase reporter assay was used to confirm their interactions. MiR-486-3p mimics/inhibitor or CTNNBIP1 overexpression lentivirus were transfected in human BMSCs (hBMSCs) and then osteogenic assay was performed. Alizarin red S (ARS) and Alkaline phosphatase (ALP) intensity with osteogenic gene expression including Runx2, Alp, Bglap and OCN was measured. Key proteins in Wnt/β-catenin pathway including active β-catenin, Bcl-2 and Cyclin D1 were assessed. Results CTNNBIP1, an inhibitor of Wnt/β-catenin signaling was upregulated while miR-486-3p was downregulated in ovariectomized (OVX) mice. CTNNBIP1 was confirmed as a target of miR-486-3p. MiR-486-3p overexpression promoted but miR-486-3p knockdown suppressed osteogenic differentiation and Wnt/β-catenin pathway. Rescue experiments further elucidated that the negative effects of CTNNBIP1 overexpression on osteoblastic differentiation and canonical Wnt signaling could be reversed by miR-486-3p mimics. Conclusion This study demonstrated that miR-486-3p sponges CTNNBIP1 thus activating Wnt/β-catenin signaling pathway to promote osteogenesis of BMSCs.