Rat Palatal Seam Distraction Osteogenesis In Proteomics Research

Part One:Histological Investigation of Sutural Distraction Osteogenesis of Midpalatal Suture in RatsObjective:To further examine the process of tissue remodeling during sutural distraction osteogenesis of midpalatal suture.Methods:Male Wistar rats were randomly divided into control,anterior maxillary expansion(AME)and posterior maxillary expansion(PME)groups, monitoring weight everyday.The AME and control rats were euthanized at various intervals over 11 days,and the dissected palates were prepared for histological examination.Results:The AME group began to recover more earlier than the PME group.The structure of the midpalatal sutures in AME group changed little during the first three days.From 5 d, chondrocytes in the inner layer of suture cartilage and osteoblasts at the end of the suture cartilage began to proliferate,and the skeletal matrix increased adjacent to the cartilage in the AME group.Later,osteoblasts proliferate more obviously.Conclusion:The AME treatment is less detriment to rat than the PME treatment.Considering the change of weight and the histological appearance,the rats of 3 d after operation should be introduced for proteomic research.Endochondral ossification in the early period and intramembranous osteogenesis in the later period should contribute more to the bone formation in sutural distraction osteogenesis.Part Two:Proteomic Research of Sutural Distraction Osteogenesis of Mid-palatal Suture in RatsObjective:To clarify the molecular mechanism for tissue remodeling.Methods:Proteins from samples in the ground midpalatal tissues obtained at the third day were subjected to two-dimensional polyacrylamide gel electrophoresis(2-DE)and matrix assisted laser desorption/ionization-time of flight mass spectrometry(MALDI-TOF MS) analysis.Validation of proteins was performed by Western blot analyses.Results:Comparative proteomic analysis showed an increased expression of 22 protein spots present in the ME group.The changes in three proteins closely related to osteogenesis(parathyroid hormone, osteoprotegerin and vimentin)were confirmed by Western blotting.Conclusion:Many proteins are over-expressed in sutural distraction osteogenesis,and they may play important roles in several biological remodeling processes.