Objective: We aimed at detecting the expression of long non-coding ribonucleic acid (lncRNA) maternally expressed 3 (MEG3) in the serum of fracture patients, and at investigating its impacts on the proliferation and differentiation of osteoblasts and the specific molecular mechanism of action.
Patients and methods: The serum samples of 48 fracture patients diagnosed in our hospital (Fracture group) and 30 healthy people receiving physical examination (Health group) were collected. The expression level of serum lncRNA MEG3 in Fracture group and Health group was measured via reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, a small interfering RNA (siRNA) was applied to construct mouse osteoblast cell line MC3T3-E1 with a stable knockout of MEG3. The growth status of the cell was observed, and the impacts of MEG3 knockout on the osteoblast proliferation were determined using cell counting kit-8 (CCK-8), a proliferation activity detection kit. Meanwhile, 5-ethynyl-2'-deoxyuridine (EdU) staining was applied to detect the proportion of EdU positive cells in the osteoblasts in Control group and MEG3 knockout group (MEG3 siRNA group). In addition, RT-PCR was performed to measure the messenger RNA (mRNA) levels of differentiation-related genes. Finally, RT-PCR and Western blotting assay were adopted to analyze the expression of the Wnt/β-catenin signaling pathway.
Results: The expression of serum lncRNA MEG3 in fracture patients was increased markedly (p<0.05). Results of in-vitro cell experiment indicated that intervention with MEG3 siRNA could obviously promote the proliferation and differentiation of osteoblast cell line MC3T3-E1. The results of RT-PCR and Western blotting assay revealed that the role of MEG3 in promoting differentiation and proliferation might be mediated by the activation of the Wnt/β-catenin signaling pathway in osteoblasts.
Conclusions: LncRNA MEG3 can promote the proliferation and differentiation of osteoblasts by activating the Wnt/β-catenin signaling pathway, so it is expected to become a new target for accelerating the fracture healing.