Proteomic Analysis of Orthodontic Force-induced Plasma from Patients

Objectives: Orthodontic teeth movement (OTM) was considered as an aseptic inflammatory process locally. Recently, our published work indicted that orthodontic force induces systemic inflammatory monocyte responses in the rat OTM model. However, little is known about systemic proteomic changes during orthodontic treatment in patients. In this study, we employed a strategy of LC-MS/MS using tandem mass tag (TMT) labeling to explore systemic protein alteration due to regional orthodontic stimulation in patients.
Methods: Peripheral blood plasma was collected from 10 healthy orthodontic patients (Female: male=1:1, aged 20~30 years old) parallel with 7 healthy volunteers (Female: male=4:3, aged 20~30 years old) at serial time intervals after OTM. Sample collection followed the Ethical Guidelines of Peking University (PKUSSIRB-201311103). All plasma samples were undergone further proteomic analysis of LC-MS/MS using tandem mass tag (TMT) labeling, gene ontology analysis (GO), protein interaction network analysis (STRING), and pathway analysis (KEGG).
Results: 295 proteins were identified in total. 16 proteins were found differentially altered in 24 hours only in plasma from orthodontic patients. With protein interaction network construction (STRING) and pathway analysis (KEGG), proteins were found strongly interacted in acute inflammatory process including complement cascade, phagosome, and important hypoxia pathway of Hif-signaling. With a further protein function (GO, gene ontology) analysis, 16 proteins were annotated mainly during biological process including acute immune responses and enriched in vesicle-related cellular component form. Among 16 force-induced proteins, Galectin-3 binding protein, ligand of Galectin-3 which was previous reported as monocyte chemo-attractant, increased significantly after force-induction after 8 hours.
Conclusions: Our work indicated, for the first time, regional orthodontic force aroused systemic proteomic changes in orthodontic patients’ plasma. Furthermore, increasing force-induced plasma Galectin-3 binding protein level partly confirmed our previous animal model of systemic inflammatory monocyte responses after orthodontic force induction.