Changes of Resolvin D1 and Its Polarization Effect on Macrophages in Mandibular Distraction Osteogenesis Promoted by Parathyroid Hormone Administration
Objective:To study the changes of Resolvin D1(RvD1)and its effect on macrophage polarization dur-ing mandibular distraction osteogenesis promoted by parathyroid hormone(PTH).Methods:The mandibular dis-traction osteogenesis model was established in 48 rabbits and the rabbits were randomly divided into two groups.The experimental group was injected with PTH 20 μg/kg intermittently after operation,while the control group was injected with normal saline.Samples were taken on the 3rd,5th,and 7th day of distraction,respectively,and the new bone tissue in the distraction area was observed by hematoxylin-eosin(HE)staining.LC-MS/MS was used to detect the content of RvD1 in the new bone tissue in the distraction zone.qPCR was used to detect the mRNA level of iNOS and Arg1 in new bone tissue.RAW264.7 cells were cultured and treated with LPS,RvD1,and LPS+RvD1,respectively.The expression level of macrophage polarization markers was detected by qPCR and flow cy-tometry.Results:HE staining and gross specimen observation showed that the new bone formation in the distraction zone of the experimental group was better than that of the control group.The content of RvD1 in the experi-mental group was significantly higher than that in the control group(P＜0.01).qPCR results showed that PTH signifi-cantly increased the expression level of M2-type polarization marker Arg1 gene in macrophages,and decreased the expression level of M1-type polarization marker iNOS(P＜0.01).In vitro,the expression level of Arg1 mRNA of M2-type polarization marker was up-regulated after RvD1 treatment,while the expression of iNOS mRNA of M1-type polarization marker was down-regulated(P＜0.01).The results of flow cytometry showed that the LPS-in-duced increase in CD86 expression was significantly reduced and CD206 expression was significantly elevated after treatment of cells with RvD1.Conclusion:Intermittent injection of PTH can increase the content of RvD1 in rabbit mandibular distraction osteogenesis.RvD1 can polarize macrophages to M2,thus exerting anti-inflammatory effects.
万方数据
维普
