title: Expression of MMP-2 and TIMP-1 during rapid maxillary expansion in rats.
abstract: OBJECTIVE
  The aim of this study was to investigate the expression of MMP-2 and TIMP-1 during midpalatal suture expansion in rats.
  
  
  METHODS
  72 male Wistar rats were randomly divided into 2 groups: the experimental group and the control group. In the experimental group, opening loops were applied across the midpalatal suture with an initial force of 50g, whereas in the control group, rats were subjected to sham installation of opening loops without activation. On day 1, 4, 7 and 14, nine rats from each group were sacrificed, and the maxillae were dissected and prepared for Immunohistochemistry (IHC) and RT- PCR examination of MMP-2 and TIMP-1 expression.
  
  
  RESULTS
  The results of IHC and Real Time PCR revealed that both protein and mRNA expression of MMP-2 and TIMP-1 were significantly increased after midpalatal expansion, and the ratio of MMP-2/TIMP-1 was also significantly enhanced.
  
  
  CONCLUSIONS
  The data suggested that MMP-2 and TIMP-1 might play an important role during the mid-palatal suture remodeling process of maxillary expansion.
authors.affiliation: The State Key Laboratory of Oral Diseases and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Chen
authors.affiliation: Stomatological Department, Yan'an Hospital of Kunming City, Kunming, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Orthodontics and Institute of Dental Research, Beijing Stomatological Hospital and School of Stomatology, Capital Medical University, Beijing, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Li
authors.affiliation: Orthodontic Department, Ningbo Dental Hospital, Ningbo City, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Orthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, China.
authors.forename: Guifeng
authors.initials: G
authors.lastname: Li
authors.affiliation: The State Key Laboratory of Oral Diseases and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China. Electronic address: shujuannzou@aliyun.com.
authors.forename: Shujuan
authors.initials: S
authors.lastname: Zou
authors.affiliation: Department of Orthodontics, UQ Oral Health Centre, University of Queensland, Herston, QLD, Australia.
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Ye
mesh_terms: D000818:Animals; D016723:Bone Remodeling; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D008437:Maxilla / Q000378:metabolism*; D010155:Palatal Expansion Technique; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D013718:Tensile Strength; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D020778:Matrix Metalloproteinase 2
keywords: Bone remodeling; Matrix metalloproteinase; Midpalatal suture; Tensile force; Tissue inhibitors of metalloproteinase