目的 ·验证抗菌肽 KR-12的类似物 KR-12-a5对人骨髓间充质干细胞（human bone marrow mesenchymal stem cells，HBMSCs）成骨分化功能的影响。方法 ·使用 HBMSCs进行成骨分化相关实验，使用 KR-12-a5作为成骨诱导条件下的附加刺激，并通过碱性磷酸酶（alkaline phosphatase，ALP）染色实验、ALP定量实验、茜素红染色和洗脱定量分析以及成骨相关基因实时荧光定量 PCR检测，验证 KR-12-a5对 HBMSCs成骨分化功能的影响。结果 ·随着 KR-12-a5刺激浓度的增加， ALP和茜素红的染色强度也随之增加；在最高浓度（ 50 μg/mL）的 KR-12-a5刺激下显示了最强的染色效果，定量测试也显示出类似的结果。在 KR-12-a5刺激 3 d后，RUNX2的 mRNA水平以药物浓度依赖的方式增加；在第 7日，KR-12-a5处理组中的 ALP、COL1A1、BSP和 BMP2的表达水平表现出明显的变化；到第 14日，OSX、OCN和 OPN水平显著增加。结论 · KR-12-a5能以药物浓度依赖的方式促进 HBMSCs的成骨分化功能。

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.