Small Molecule Nitazoxanide Inhibits Osteogenic Differentiation and Promotes Adipogenic Differentiation of Bone Marrow Mesenchymal Stem Cells.

OBJECTIVE: To investigate the potential effect of small molecule nitazoxanide (NTZ) on the osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). METHODS: Cell counting Kit-8 assay was used to examine the effect of NTZ on proliferation of BMSCs. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis were used to measure the expression of osteogenic and adipogenic marker gene. Alkaline phosphatase (ALP) staining and activity assay and Alizarin Red S (ARS) staining were used to investigate the effect of NTZ on osteogenesis. Oil red O (ORO) staining assay was used to assess the impact of NTZ on adipogenesis. RESULTS: NTZ significantly suppressed the osteogenic differentiation but promoted the adipogenic differentiation of BMSCs. Mechanistically, NTZ regulated osteogenic/adipogenic differentiation of BMSCs by inhibiting the Wnt/ß-catenin signalling pathway. The addition of Wnt/ß-catenin signalling pathway activator, lithium chloride, could reverse the effect of NTZ on BMSCs. CONCLUSION: NTZ affected osteogenic and adipogenic differentiation of BMSCs with the involvement of Wnt/ß-catenin signalling pathway. This finding expanded the understanding of NTZ pharmacology and indicated that NTZ might have an adverse effect on bone homeostasis.

The effect of simvastatin on chemotactic capability of SDF-1α and the promotion of bone regeneration.

The purpose of this study was to investigate the cooperative effects of simvastatin (SIM) and stromal cell-derived factor-1α (SDF-1α) on the osteogenic and migration capabilities of mesenchymal stem cells (MSCs), and construct a cell-free bone tissue engineering system comprising SIM, SDF-1α and scaffold. We found that 0.2 µm SIM significantly increased alkaline phosphatase activity (P < 0.05) of mouse bone marrow MSCs with no inhibition of cell proliferation, and enhanced the chemotactic capability of SDF-1α (P < 0.05). Next, we constructed a novel cell-free bone tissue engineering system using PLGA loaded with SIM and SDF-1α, and applied it in critical-sized calvarial defects in mice. New bone formation in the defect was evaluated by micro-CT, HE staining and immunohistochemistry. The results showed that PLGA loaded with SIM and SDF-1α promoted bone regeneration significantly more than controls. We investigated possible mechanisms, and showed that SDF-1α combined with SIM increased MSC migration and homing in vivo, promoted angiogenesis and enhanced the expression of BMP-2 in newly-formed bone tissue. In conclusion, SIM enhanced the chemotactic capability of SDF-1α and the cell-free bone tissue engineering system composed of SIM, SDF-1α and scaffold promoted bone regeneration in mouse critical-sized calvarial defects.