Time–dependent variation in expression patterns of Lysyl Oxidase, Type I Collagen and tropoelastin mRNA in response to orthodontic force application

Abstract

ObjectiveOrthodontic tooth movement is characterized by reorganization of collagen and elastin fibers. Lysyl oxidase (LOX), the copper containing amine oxidase is involved in the post translational stabilization of these fibers. The objective of this study was to quantitatively evaluate mRNA expression of lysyl oxidase, type I collagen (COL I) and tropoelastin and find out time dependent correlation in expression of lysyl oxidase mRNA with Type I collagen or tropoelastin messenger RNA (mRNA). DesignStudy evaluated 12 samples grouped into 4, Group A (control), experimental groups B, C and D collected after 7, 14, 28 days of force application respectively. mRNA expression was assessed using qRT-PCR. ResultsThe mRNA expression of Type I Collagen increased 15, 39, 20-fold, lysl oxidase increased 16, 27, 14-fold and tropoelastin decreased 8, 5, 13-fold in groups B, C and D when compared to control. The results were found to be statistically significant when one-way analysis of variance (ANOVA) and post hoc test was performed. Tropoelastin mRNA showed negative correlation with that of lysl oxidase (r2= -0.74) and COL1 (r2= -0.42). ConclusionsForce application resulted in time-dependent variation in expression of type I collagen, lysl oxidase and tropoelastin mRNA. Type I Collagen and lysl oxidase mRNA expression peaked in samples collected after 14 days of force application, while decreased expression pattern for tropoelastin mRNA was observed.