Myofibroblast Gene Expression Profile after Tooth Extraction in the Rabbit

Abstract

After tooth extraction, the alveolar bone tends to shrink in volume, especially on the vestibular side. The role of myofibroblasts in bone remodeling has not been sufficiently investigated. The aim of the present study was to explore the gene expression related to myofibroblasts presence and activity during a 90-day healing period after tooth extraction. The study included 36 rabbits, and a single tooth extraction was performed on each rabbit. The extractive sockets were randomly distributed to natural healing or to scarification of the wound. The sacrifices were staggered in such a manner that animals contributed with sockets representing 2, 7, 15, 30, 60, and 90 days of healing. Nanostring technology was used to evaluate the expression of a wide panel consisting in 148 genes related to the activation, induction, and suppression of myofibroblasts, socket microenvironment, and autophagy. We found that the expression profile of this custom panel was time-related. The post-extractive socket was subjected to significant gene expression changes after 15 days: the genes involved in the induction of myofibroblasts were up-regulated in the first 15-day period and down-regulated during the rest of the follow-up. The study suggested that myofibroblasts play a major role in the immediate 15-day period following tooth extraction.

Keywords: alveolar bone; fibroblasts; gene expression; wound healing.

Figure 1

Hematoxylin and eosin stained histological sections of representative sockets at 2 (T1), 7 (T2), 15 (T3), 30 (T4), 60 (T5), and 90 (T6) days post-extraction. For each group, 4 × and 10 × magnifications are reported.

Figure 2

Unsupervised hierarchical clustering analysis of post-extractive sockets using the 148 genes of the custom panel. The two main clusters are indicated with numbers 1 and 2.

Figure 3

Hierarchical clustering analysis of post-extractive socket samples using the 74 differentially expressed genes from the custom panel. The two main clusters are indicated with the numbers 1 and 2. The columns represent the samples, and the lines represent the genes. Red color indicates high gene expression levels; green color indicates low gene expression levels.