Basic Research of Mechanical Stimulation/Iron on the Regulation of Osteoblast Activity to Promote Bone Healing
Objective:To investigate the potential mechanism of mechanical stimulation/iron in promoting bone healing by mediating osteoblast activity through the COX2/PGE2 pathway in vitro and in vivo.Methods:18 male Balb/c mice with 10-week-old were randomly divided into normal group,model group and MS+iron group.The animal model of tibial fracture was prepared.The concentrations of C-terminal cross-linked peptide(CTx)and osteocalcin(OC)of type Ⅰ collagen were detected by enzyme-linked immunosorbent assay(ELISA).Osteoblasts in model group were cultured,and Western Blot was used to detect the expression of related proteins in osteoblasts.The total amount of COX2 protein in the nuclear mem-brane of osteoblasts was detected by immunofluorescence.The effects of iron on COX2/PGE2 pathway and apoptosis of osteoblasts were analyzed by flow cytometry.Results:Compared with model group,the fracture line of MS+iron group was blurred,the content of CTx in serum was decreased and the content of OC was increased,and the levels of bone gla-protein(BGP),alkaline phosphatase(ALP)and COI1 were increased.Iron can increase the content of CTx and decrease the content of OC in osteoblasts.The protein levels of BGP,ALP and COI1 in model group were significantly higher than those in normal group and high/low iron group.Iron activated the COX2/PGE2 pathway of osteoblasts,and the high iron group can significantly increase the protein levels of COX2,PGEX and PGE2.The fluorescence intensity of COX2 on the nuclear membrane of osteoblasts was significantly increased compared with that in the low iron group and the control group.The apoptosis rate of osteoblast could be significantly decreased by up-regulating poly(ADP-ribose)polymerase(PARP)and Bax levels and down-regulating Bcl2 levels in high iron group,while the levels of COX2,PGE2,ALP and COI1 in high iron group were significantly increased.Conclu-sion:Mechanical stimulation/iron can promote bone healing through osteoblast activity mediated by COX2/PGE2 pathway in vitro and in vivo,which expands the application of mechanical stimulation/iron in bone healing.
mechanical stimulationironosteoblastsignal pathbone union
万方数据
维普
