Abstract: Objective · To investigate the effect of KR-12 analog, KR-12-a5, on osteogenic differentiation of human bone marrow mesenchymal stem cells (HBMSCs). Methods · Osteogenic differentiation-related experiments were performed using HBMSCs. KR-12-a5 was used as additional stimulation under osteogenesis inducing environment.alkaline phosphatase (ALP) staining assay, ALP quantitative assay, alizarin red staining and elution quantitative analysis, and real-time quantitative polymerase chain reaction (RT-qPCR), the effect of KR-12-a5 on osteogenic differentiation of HBMSCs was verified. Results · As the concentration of KR-12-a5 increased, the staining intensity of ALP and alizarin red also increased. The strongest staining effect was exhibited at the highest concentration (50 μg/mL) of KR-12-a5. Quantitative tests showed similar results. After 3 days of stimulation with KR-12-a5, the mRNA level of RUNX2 increased in a dose-dependent manner. On the 7th day, the levels of ALP, COL1A1, BSP and BMP2 in the KR-12-a5-treated group showed significant changes. On the 14th day, OSX, OCN and OPN levels increased significantly. Conclusion · KR-12-a5 promoted the osteogenic differentiation of HBMSCs in a dose-dependent manner.

Key words: KR-12-a5, antimicrobial peptides (AMPs), osteogenic differentiation, human bonemarrowmesenchymal stemcells(HBMSCs)