Copyright (c) 2024 Juan Liu, Hong Ren, Shuo Zhang, Guiyong Yu
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
The undersigned hereby assign all rights, included but not limited to copyright, for this manuscript to CMB Association upon its submission for consideration to publication on Cellular and Molecular Biology. The rights assigned include, but are not limited to, the sole and exclusive rights to license, sell, subsequently assign, derive, distribute, display and reproduce this manuscript, in whole or in part, in any format, electronic or otherwise, including those in existence at the time this agreement was signed. The authors hereby warrant that they have not granted or assigned, and shall not grant or assign, the aforementioned rights to any other person, firm, organization, or other entity. All rights are automatically restored to authors if this manuscript is not accepted for publication.MiRNA-21 promotes humeral fracture healing by targeting SMAD7 to activate the Wnt/β-catenin pathway
Corresponding Author(s) : Guiyong Yu
Cellular and Molecular Biology,
Vol. 70 No. 7: Forthcoming
Abstract
MiRNAs are crucial regulators of bone regeneration after fractures. MiR-21 has been revealed to contribute to osteogenesis in bone repair, while its function on humeral fracture remains unknown. MiR-21 level in serum or tissues was evaluated using qRT-PCR. Humeral fracture rat models were established and the effects of miR-21 on humeral fracture healing in vivo were explored by the administration of agomiR-21. The impact of miR-21 on the function of osteoblasts in vitro was explored using mouse osteoblastic (MC3T3-E1) cells, with CCK-8 and EdU assays for osteoblast proliferation assessment and Transwell assays for the evaluation of osteoblast migration ability. The osteoblast apoptosis was subject to flow cytometry. The downstream target of miR-21 was predicted based on bioinformatics analysis, and SMAD7 was screened with a conserved binding site to miR-21 across species. Rescue assays were conducted to explore the impact of miR-21/SMAD7 axis on MC3T3-E1 osteoblast function in vitro. ELISA or western blot was adopted to determine the Wnt/β-catenin pathway components. MiR-21 is down-regulated in humeral fracture patients relative to healthy controls, and its level increased over time in the early-stage post-fracture. In the humeral fracture rat models, administration with agomir-21 significantly promoted osteogenesis and improved fracture healing. MiR-21 also improved the proliferative potential, migration and differentiation ability and inhibited the apoptosis of MC3T3-E1 osteoblasts in vitro. MiR-21 bound to SMAD7 and negatively modulated SMAD7 expression. MiR-21 played a pro-osteogenic role by targeting SMAD7 for Wnt/β-catenin activation. In summary, miR-21 promotes bone regeneration post-humeral fracture by targeting SMAD7 for Wnt/β-catenin activation, which possibly offers new therapeutic targets related to fracture healing.
Keywords
Download Citation
Endnote/Zotero/Mendeley (RIS)BibTeX