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

Background: Dysfunction in the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) leads to bone loss/osteoporosis. The catenin beta interacting protein 1 (CTNNBIP1) is an inhibitor of Wnt/beta-catenin signaling, whose role in osteogenesis remains elusive. This study aimed to reveal the effects of miR-486-3p/CTNNBIP1 in osteogenesis. Methods: Bone marrow samples from healthy individuals and osteoporosis patients and mice with sham or ovariectomy (OVX) surgeries were collected. Levels of CTNNBIP1 and miR-486-3p were assessed. A dual-luciferase reporter assay was used to confirm the interactions between CTNNBIP1 and miR-486-3p. MiR-486-3p mimics/inhibitor or CTNNBIP1 overexpression lentiviruses were transfected to human BMSCs (hBMSCs) and an osteogenic assay was performed. Alizarin red S (ARS) and Alkaline phosphatase (ALP) intensity and expression of osteogenic genes Runx2, Alp, Cola1 and Bglap were measured. Key proteins in the Wnt/beta-catenin pathway including active beta-catenin, Bcl-2, and Cyclin D1 were assessed. Results: CTNNBIP1 was upregulated while miR-486-3p was downregulated in osteoporosis patients and OVX mice. CTNNBIP1 was confirmed as a target of miR-486-3p. MiR-486-3p overexpression promoted, while miR-486-3p knockdown suppressed, osteogenic differentiation and Wnt/beta-catenin signaling. Rescue experiments confirmed the negative effects of CTNNBIP1 overexpression on osteoblastic differentiation and that miR-486-3p mimics could reverse canonical Wnt signaling. Conclusion: This study demonstrated that miR-486-3p targets CTNNBIP1, thus activating the Wnt/beta-catenin signaling pathway to promote osteogenesis of BMSCs. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

Dysfunction in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is regulated by miR-486-3p/CTNNBIP1 axis, where miR-486-3p promotes osteogenesis through activating the Wnt/beta-catenin signaling pathway, while overexpression of CTNNBIP1 inhibits osteogenic differentiation.