title: Effects of continuous and interrupted forces on gene transcription in periodontal ligament cells in vitro.
abstract: The biological mechanisms of tooth movement are based on the response of periodontal tissues to mechanical forces. The final result of these responses is remodeling of the extracellular matrix. Tissue reactions may vary depending upon the type, magnitude and duration of the applied forces. The purpose of the present study was to analyze the effects of centrifugal force on the transcription of collagen type-I (Col-I), matrix metalloproteinase-1 (MMP-1), and tissue inhibitor of metalloproteinase- 1 (TIMP-1) genes in human periodontal ligament (PDL) fibroblasts. Human fibroblasts obtained from the PDL were cultured and subjected to centrifugal forces (36.3 g/cm(2)) for 30, 60 and 90 min continuously. This was also carried out interruptedly, three times for 30 min and six times for 15 min. The mRNAs encoding for Col-I, MMP-1, and TIMP-1 were quantified using RT-PCR. The mRNA levels of Col-I and MMP-1 were increased when continuous force was applied for 30 min and 60 min respectively. The interrupted force had almost no effect on Col-I, MMP-1 and TIMP-1 genes. These results indicate that continuous forces may have a greater effect in inducing gene expression during the remodeling process of PDL compared to interrupted forces with short rest periods.
authors.affiliation: Dental Research Center, Faculty of Dentistry, Tehran University of Medical Sciences, Iran.
authors.forename: Ninette
authors.initials: N
authors.lastname: Hacopian
authors.forename: Tahereh Hosseinzadeh
authors.initials: TH
authors.lastname: Nik
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Ghahremani
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Rahimi
authors.forename: Seyed Nasser
authors.initials: SN
authors.lastname: Ostad
mesh_terms: D002478:Cells, Cultured; D002498:Centrifugation; D024042:Collagen Type I / Q000235:genetics*; D005347:Fibroblasts / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D020781:Matrix Metalloproteinase 1 / Q000235:genetics*; D040542:Mechanotransduction, Cellular; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical; D013997:Time Factors; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D024042:Collagen Type I; D012333:RNA, Messenger; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1