Jagged1 promotes osteoclast differentiation and inhibits proliferation by activating of Notch signaling pathway

Abstract

Objective To study the role of Jadded1 and Notch signaling pathway played in the differentiation and proliferation of osteoclasts derived from human circulating CD14 + monocytes.Methods Peripheral blood CD14 + monocytes were isolated from healthy adult by Ficoll density gradient centrifugation combined with magnetic beads separation.Recombinant protein Jagged1 and γ-Secretase Inhibitor (DAPT) with Jagged1 were added to the culture system of CD14 + monocytes respectively.The mRNA expression of osteoclast markers tartrate-resistant acid phosphatase (TRAP),cathepsin K (CK),calctionin receptor (CTR) and Notch key target genes hairy and enhancer of split-1 (HES-1) and HES-related with YRPW motif-1 (HEY-1) were measured by quantitative real-time quantitative polymerase chain reaction (Real-time PCR).The formation of osteoclast,bone resorption,Notch expression and proliferation of CD14 + monocytes were detected by TRAP staining,scanning electron microscope,and cell counting kit-8 (CCK-8).Results High expression of Jagged1 in bone metastases specimens was observed in contrast of no expression or low expression in adjacent tissues.TRAP,CK,CTR,HES-1 and HEY-1 mRNA expression were significantly higher than the control group and DAPT group in Jadded1 group (P ＜ 0.05).TRAP + cell count,osteolytic area was significantly increased in Jagged1 group when compared with control and DAPT group,and no significant difference observed between the last two groups.Cell proliferation was inhibited in Jagged1 group also (P ＜ 0.05).Conclusion Jagged1 promotes osteoclast differentiation and inhibits proliferation by activating Notch signaling pathway. Key words: Jagged1 ; Osteoclasts ; Notch ; Differentiation ; Proliferation