Notch信号促进核因子κB受体活化因子配体诱导的破骨细胞分化的体外研究

Notch signaling promotes receptor activator of nuclear factor kappa B ligand-induced ostoclastogenesis of RAW264.7 cells in vitro

目的探讨Notch信号抑制对核因子κB受体活化因子配体(RANKL)诱导的小鼠RAW264.7细胞向破骨细胞分化的影响。方法建立RANKL诱导的小鼠RAW264.7细胞体外分化模型,实时定量聚合酶链反应(real-time PCR)检测Notch信号成分(Notch1、Notch2、Delta1、Jagged1)、下游靶基因Hes1以及破骨细胞标志基因抗酒石酸酸性磷酸酶(TRAP)和Cathepsin K在诱导前后mRNA的表达。在诱导体系中加入不同浓度的γ分泌酶抑制剂(GSI),抑制Notch受体的表达,TRAP染色检测破骨细胞分化的变化情况。结果 50 ng·m L-1 RANKL诱导小鼠RAW264.7细胞3 d,Notch1、Notch2、Delta1、Jagged1及Hes1的mRNA表达均有不同程度的提高,其中以Notch2、Jagged1增高最明显;破骨细胞标志基因表达显著增高。在RANKL诱导的同时加入不同浓度GSI,抑制Notch的表达,可致Notch下游靶基因Hes1表达下降,同时TRAP阳性细胞计数显著减少,且呈剂量依赖性。结论 Notch信号可促进RANKL诱导的RAW264.7细胞向破骨细胞分化。

Objective This study aims to explore the effect of Notch signaling depression on the receptor activator of nuclear factor kappa B ligand （RANKL）-induced osteoclastogenesis of RAW264.7 cells. Methods Mice RAW264.7 cells were cultured and differentiated into osteoclasts with the induction of RANKL. The expressions of Notchl, Notch2, Deltal, Jaggedl, Hesl, tartrate-resistant acid phosphatase （TRAP）, and Cathepsin K genes during osteoclastogenesis were analyzed using real-time polymerase chain reaction. Osteoclast formation was analyzed using TRAP assay with suppression of Notch receptors by a selective γ-secretase inhibitor （GSI）. Results Notchl, Notch2, Deltal, Jaggedl, and Hesl expressions in RAW264.7 cells were upregulated following 50 ng·mL^-1 RANKL stimulation for 3 d, concomitant with the expression of the osteoclast differentiation markers TRAP and Cathepsin K. Notch2 and Jaggedl had the most remarkable increase in the Notch family members. GSI inhibited RANKL-induced osteoclastogenesis of RAW264.7 cells and Hesl expression dose- dependently. Conclusion Notch signaling activation may promote RANKL-induced osteoclastogenesis of RAW264.7 cells.