Curcumin stimulate osteoblast differentiation through regulating p300 Histone acetyltransferase

The ability to control the fate of mesenchymal stem cells (MSCs) into osteogenic lineages would be of crucial importance in cell-based therapies and regenerative medicine. Epigenetic mechanisms are known as important modifiers of stem cell differentiation. It has been revealed p300, a Histone acetyltransferase, has positive effects on osteogenesis. Curcumin has a variety of therapeutic properties and regulate epigenetic mechanisms as well. Hence, in the present study, we aim to explore whether curcumin mediates osteoblast differentiation of human bone marrow MSCs (hBMSCs) through regulation of p300 epigenetic factor. MSCs were isolated from human bone marrow and expanded under in vitro condition. Cell viability assay was performed to determine the cytotoxicity of curcumin on hBMSCs. The expression levels of osteogenic-related genes in the absence and presence of curcumin were assessed using qRT-PCR. Additionally, the epigenetic factor, p300 Histone acetyltransferase was assessed in hBMSCs culture after 14 and 21 days. No cytotoxic effect was detected at concentrations of 10 μM and 15 μM of curcumin as evidenced by MTT results. qRT-PCR results demonstrated that curcumin significantly enhanced the expression level of early and late osteogenic markers at both time points in a time/dose-dependent manner. Moreover, the expression level of p300 significantly enhanced in the presence of curcumin compared to control groups. It is concluded that upregulation of p300 marker, which is only occurred in curcumin treated cultures, is attributed to effects of curcumin on osteogenic differentiation of hBMSCs. Therefore, curcumin as a natural compound had ability to act as an epigenetic regulator and stimulate osteoblast differentiation.