R432 – Gene Expression of the Remodeling Rat Vocal Fold Wound

Problem The authors investigated the expression of key extracellular matrix genes after vocal fold wounding in a rat model to better understand the reparative mechanisms of tissue repair during the remodeling phase of vocal fold injury. Methods Bilateral vocal fold wounds were created in 30 rats. Injured vocal fold specimens were harvested 1, 3, 7, 14, 28, and 56 days after wounding. 5 unwounded rats were used to establish baseline for polymerase chain reaction (PCR). The authors used real-time PCR to quantify messenger RNA expression of procollagen type I, III, interleukin-1 beta (IL-1 beta), decorin, and hyaluronan synthase (HAS) −1, −2, and −3. Analysis of variance was used to detect main effects for gene expression. Post-hoc tests were used to make comparisons between time points. Results Procollagen type I expression was decreased from baseline on post-injury day 1, 28, and 56. Procollagen type III was decreased on post-injury day 1 and 56, and increased from baseline on post-injury day 14. IL-1 beta expression was increased from baseline on post-injury day 1, 3, and 7. Decorin expression was decreased from baseline on post-injury day 1, 3, 7, and 56. HAS-1 expression was decreased from baseline at all post-injury time points. HAS-2 expression was increased from baseline on post-injury day 3, and decreased from baseline on post-injury day 14, 28, and 56. HAS-3 expression was decreased from baseline on post-injury day 1, 28, and 56. Conclusion Findings provide temporal changes in the expression of key extracellular matrix genes during a remodeling phase of vocal fold injury in a rat wound model. Significance Vocal fold wound models provide a means for investigating tissue reparative processes and molecular mechanisms controlling synthesis and degradation of the vocal fold extracellular matrix. Support Vanderbilt University Medical Center.