Ferulic acid promotes osteogenesis of bone marrow-derived mesenchymal stem cells by inhibiting microRNA-340 to induce β-catenin expression through hypoxia.

Osteogenic differentiation is regulated through multiple signaling networks that may include responses to hypoxia. Antioxidant ferulic acid (FA) can promote hypoxia signaling by inducing hypoxic-induced factor (HIF). However, whether FA could affect osteogenesis has not been explored. We examined human bone marrow-derived mesenchymal stem cell (MSC) following FA treatment. The expression of β-catenin was measured, and candidate microRNAs that target β-catenin were studied. The involvement of hypoxia was investigated in miR-340-5p that contains hypoxia response elements (HRE) in the promoter region. Further, the osteogenic potential of FA-treated MSC was assessed by alkaline phosphatase (ALP) activity and alizarin red staining assays. Osteoblast marker gene expressions were also compared between controls and FA-treated cells. FA induced β-catenin expression in MSC. This effect is likely mediated through a derepression of β-catenin 3'-UTR inhibition by miR-340-5p. HIF-1α, which suppressed miR-340-5p promoter activation through HRE motifs, was induced by FA. The induction of β-catenin signaling by FA was consistent with an enhancement in osteogenesis of FA-treated MSC, which could be attenuated by miR-340-5p overexpression. Analysis of the signaling networks induced by FA reveals that hypoxia may promote the osteogenic program in mesenchymal stem cells via a novel microRNA pathway.