The regulatory roles of miR-26a in the development of fracture and osteoblasts.

Abstract

BackgroundMicroRNAs (miRNAs) play a vital role in the bone development and bone regeneration. In this study, we investigated the effects of miR-26a in osteoblasts and fractures.MethodsHuman osteoblasts were cultured and used for analysis. To identify differential miRNAs in blood samples from patients with fractures and healthy controls, quantitative real-time polymerase chain reaction (qRT-PCR) analysis was performed. Human osteoblasts were transfected with miR-26a mimics, miR-26a inhibitor, or their corresponding negative controls (NCs), respectively. MTT assay was performed to identify the effects of miR-26a on the cell viability of osteoblasts. EdU staining was applied to detect the proliferation of osteoblasts. Trypan blue staining was utilized to analyze the effects of miR-26a on the cell death of osteoblasts. Terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) staining was used to detect apoptotic osteoblasts. Alizarin red S (ARS) staining and qRT-PCR analysis were utilized to measure the mineralized nodule formation to evaluate the bone formation of osteoblasts. Dual luciferase reporter assay and western blot analysis were performed to detect the relationship between miR-26a and its target gene.ResultsThe results of qRT-PCR analysis identified miR-26a as our miRNA of interest and indicated that miR-26a was significantly decreased in patients with fractures. Overexpression of miR-26a significantly increased the cell viability and proliferation of osteoblasts. An increase in miR-26a reduced the cell death and apoptosis of osteoblasts, and promoted the osteoblastic activity and mineralized nodule formation. Dual luciferase reporter assay, qRT-PCR and western blot analysis showed that miR-26a could negatively regulate the expression of phosphatase and tensin homolog (PTEN).ConclusionsMiR-26a promoted new bone regeneration via regulating the functions of osteoblasts by targeting its target gene PTEN. Therefore, we propose that targeting miR-26a may be a novel therapeutic method for bone regeneration and treating fractures.