Enamel matrix derivative expedites osteogenic differentiation of BMSCs via Wnt/ß-catenin pathway in high glucose microenvironment.

INTRODUCTION: The influence of enamel matrix derivative (EMD) on proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was explored in high glucose (HG) microenvironment with interaction of Wnt/ß-catenin pathway. MATERIALS AND METHODS: Extraction of BMSCs from Sprague-Dawley rats, culture, and identification were manifested. The cells were treated with different concentration of EMD in HG to figure out the most available concentration for proliferation and osteogenic differentiation. Then, observation of cell growth curve and cell cycle changes, and detection of Osterix, runt-related transcription factor 2 (Runx2), COL-I, early osteogenic indexes, Calcium salt deposition, and ß-catenin protein in Wnt/ß-catenin pathway were assured. After adding Wnt/ß-catenin pathway inhibitor (XAV-939) in the cells with osteogenesis induction, detection of binding of ß-catenin to Osterix was clarified. RESULTS: Via identification BMSCs cultured in vitro was qualified. Different concentrations of EMD could accelerate cell proliferation in HG and osteogenesis induction, and 75 µg/mL EMD had the best effect. The HG augmented BMSCs proliferation and the propidium iodide index of flow cytometry cycle was elevated in HG, which were strengthened via the EMD. After BMSCs' osteogenesis induction, Osterix, Runx2, CoL-1, early osteogenic indexes, and calcium salt deposition were reduced, but elevated via EMD. ß-Catenin was the lowest in the HG, but elevated after EMD. After addition of XAV-939, reduction of ß-catenin and the downstream (Osterix and Runx2) were manifested. Detection of binding protein bands was in ß-catenin and Osterix of the HG after EMD treatment. CONCLUSION: EMD may facilitate the osteogenic differentiation of BMSCs via activating the Wnt/ß-catenin pathway in HG.

miR-153-3p inhibits osteogenic differentiation of BMSCs by down-regulating the expression of RUNX2 in a high glucose environment.

To study the effect of miR-153-3p on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in a high glucose environment and its potential mechanism. The results showed that high glucose inhibited the osteogenic differentiation of BMSCs, and the expression of miR-153-3p increased during osteogenic differentiation. Further experiments found that in BMSCs induced by high glucose, overexpression of miR-153-3p inhibited the osteogenic differentiation of BMSCs, and the expressions of osteogenesis-related genes bone sialoprotein, Collagen I and alkaline phosphatase were down-regulated, while silencing of miR-153-3p alleviated the inhibition effect. The dual-luciferase reporter gene assay confirmed that the 3'-untranslated region (3'-UTR) of runt related transcription factor 2 (RUNX2) had a targeted binding site with miR-153-3p and a negative regulatory effect. Molecular studies further confirmed that miR-153-3p inhibited the osteogenic differentiation of BMSCs by targeting the 3'-UTR of RUNX2. In conclusion, our study found that as one key regulator of high glucose affecting the osteogenic differentiation of BMSCs, miR-153-3p may play a negative regulatory role by inhibiting the expression of RUNX2.