Up-regulation of multiple proteins and biological processes during maxillary expansion in rats

Junqing Ma,Weibing Zhang,Lin Wang,Roger J Smales,Yunxia Wu,You Huang,Yongchu Pan

doi:10.1186/1471-2474-9-37

Junqing Ma, Weibing Zhang + Show 5 more

Open Access

https://doi.org/10.1186/1471-2474-9-37

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Abstract

BackgroundMaxillary expansion (ME) is a common practice in orthodontics that aims to increase the constricted maxillary arch width. Relapse often occurs, however, and better treatment strategies are needed. In order to develop a more effective method, this study was designed to further examine the process of tissue remodeling during ME, to identify the changes in expression of several proteins of interest, and to clarify the molecular mechanism responsible for tissue remodeling.MethodsMale Wistar rats were randomly divided into control and ME groups. The rats were euthanized at various intervals over 11 days, and the dissected palates were prepared for histological examination. The structure of the midpalatal sutures changed little during the first three days. Proteins from samples in the ground midpalatal tissues obtained on 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 protein expression was performed by Western blot analyses.ResultsFrom day 5, 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 later adjacent to the cartilage in the ME group. Comparative proteomic analysis showed increases in 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.ConclusionMany proteins are over-expressed during ME, and they may play an important role in the remodeling process.

Highlights

Maxillary expansion (ME) is a common practice in orthodontics that aims to increase the constricted maxillary arch width
Effect of ME on body weight Compared with the control group, the body weights of the rats in the ME group decreased during the first two days after operation and started recovering on the third day (Figure 1)
When stress is loaded onto the midpalatal suture, the mechanical force is transformed into a biological signal that results in a series of biological events, such as chondrocyte hypertrophy, angiogenesis, cartilage and other tissue resorption, skeletal matrix formation, and matrix calcification

Summary

Introduction

Maxillary expansion (ME) is a common practice in orthodontics that aims to increase the constricted maxillary arch width. In order to develop a more effective method, this study was designed to further examine the process of tissue remodeling during ME, to identify the changes in expression of several proteins of interest, and to clarify the molecular mechanism responsible for tissue remodeling. Maxillary expansion (ME), or palatal expansion, is a common practice in orthodontics that aims to increase constricted maxillary arch width. Several studies in rats and other animals have been undertaken to explore the mechanism of tissue remodeling in order to improve the efficacy of ME. Previous studies have been limited to investigating one or a few proteins, but the complex biological mechanism of ME necessitates the use of a global proteomic analysis to improve the understanding of the process in greater detail

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