Zoledronic acid epigenetically alleviates high-glucose-suppressed osteogenic differentiation of MC3T3-E1 cells.

Abstract

Due to the impact of excessive glucose on osteogenic differentiation, diabetic osteopathy frequently results in skeletal fragility, osteoporosis, and bone pain. Zoledronic acid, a bisphosphonate (BP) that effectively inhibits osteoclastic bone resorption is given yearly to improve bone mineral density (BMD) in patients with osteoporosis. However, the detailed molecular mechanisms remained unclear. This study investigates the possible pathways by which zoledronic acid regulates osteogenesis when blood glucose levels are high. MC3T3-E1 cells were treated with one mM zoledronic acid or not in a standard or high glucose culture medium. A quantitative polymerase chain reaction (qPCR) assay was utilized to assess the expression of the target candidate genes, including RUNX2, MALAT1, miR-133, miR-20a, and miR-204. In a high-glucose condition, zoledronic acid treatment significantly lowered MALAT1 (p < 0.0001) and miR-20a (p < 0.0001) expression. Conversely, in a high-glucose condition, RUNX2, miR-133, and miR-204 expressions were found to be significantly increased in the zoledronic acid treatment group as compared to no treatment (all p < 0.0001). In conclusion, under a high-glucose environment, zoledronic acid can modulate the expression of the RUNX2 transcription factor through epigenetic regulation.