Quantitative analysis of matrix metalloproteinase-1 gene expression in cultured fibroblasts subjected to centrifugal forces

Mechanical stress caused by orthodontic appliances transmits forces directed towards the periodontal ligament (PDL) and bone causing tooth movement. Forces are initially transmitted to the PDL cells which are embedded in the extracellular matrix. The PDL and bone are mainly composed of collagen type 1. Tooth movement occurs because of the release of enzymes by cells which degrade collagen type 1. Matrix metalloproteinase (MMP) is a family of zinc and calcium-dependent proteases that degrade different types of collagens. Specifically, MMP-1 degrades triple helical fibrillar collagens mainly found in bone. The purpose of the study was to analyze the gene expression of MMP-1 in cultured fibroblasts subjected to orthodontic forces. Fibroblasts were subjected to centrifugal forces converted from orthodontic forces (20, 60, 120 and 200g). Then after, mRNA extraction was done followed by real-time polymerase chain reaction to determine MMP-1 gene expression. Statistical analysis was performed and a p value less than 0.05 was considered significant. MMP-1 gene expression increased when cells were subjected to force treatment. Data analysis showed statistical significant p values between the control and experimental groups and between experimental groups. No expression was noted for the control suggesting that MMP-1 was only expressed when mechanical load was applied. In conclusion, cultured huma fibroblasts expressed MMP-1 gene and the expression is directly proportional to the amount of centrifugal forces. MMP-1 is expressed during the initial stage of orthodontic load application suggesting its prime role in periodontal remodeling processes