Effects of PKC Inhibitor on Osteogenic Differentiation of Stem Cells
Severe resorption of alveolar bone after tooth loss/extraction, makes it difficult to restore the missing teeth with dental implants or prosthodontic approaches. Small-molecule synthetic regulators of differentiation and maturation of osteoblasts and/or osteoclasts have great potential for applications in bone regenerative medicine. Recent reports have shown that protein kinase C (PKC) inhibitor promote osteogenic differentiation. Iso-H-7 is a broad-range PKC inhibitor.
The aim of this study was to investigate the effect of iso-H-7 on the osteogenesis of stem cells in vitro and in vivo.
Mouse bone marrow-derived mesenchymal stem cells (BMSCs) and mouse gingiva-derived induced pluripotent stem cells (iPSCs) were maintained for 28 days in osteogenic induction medium containing iso-H-7. The PKC protein expression in BMSCs and iPSCs was determined by Western blotting. The effects of iso-H-7 on the cell proliferation of BMSCs and iPSCs were evaluated by a WST-1 assay. The expression of osteogenic marker genes and the mineralized matrix formation of BMSCs and iPSCs were evaluated by real-time reverse transcriotion-polymerase chain reaction and Alizarin red S staining, respectively. A collagen graft containing iso-H-7 was transplanted into rat calvarial bone defects, and iso-H-7 was injected into the defects every third day. After 21 days, the bone formation was assessed by histological (HE staining) and micro-CT analyses.
Results: The expression of PKC protein in BMSCs and iPSCs was detected by Western blotting. Iso-H-7 did not affect the cell proliferation and the expression of osteogenic marker genes and extracellular matrix mineralization of the BMSCs and iPSCs were significantly enhanced (P<0.01). After 21 days, histological and micro-CT analyses showed that iso-H-7 had enhanced new bone formation in the calvarial defects by increased the bone mineral content and volume.
Conclusions: These results suggest that iso-H-7 promotes osteogenesis in BMSCs and iPSCs in vitro. Additionally, iso-H-7 may promote new bone formation in vivo.