Importance of Housekeeping Gene Optimization for the Analysis of mRNA Expression During Wound Healing in a Third-Degree Burn Injury Model

Wound healing evaluation methods in a third-degree burn injury model are categorized as histological (re-epithelialization and granulation tissue formation) and molecular (quantitative polymerase chain reaction). In general, mRNA expression is normalized to those of the housekeeping gene. Although the housekeeping gene expression is generally stable, it has been reported that the stability of these genes depends on the wound healing process and treatment method. In this study, we identified the most stable housekeeping gene (TATA-binding protein) for studying gene expression in a third-degree burn injury model, in which wound healing was promoted by grafting human amnion-derived mesenchymal cells. We investigated the wound healing effect of human amnion-derived mesenchymal cells in the injury model. The formation of granulation tissue, the differentiation from fibroblasts to myofibroblasts, and functional vascular structure were promoted in the full-thickness skin excision site by treatment with these cells. The expression of angiogenic, pro-inflammatory and anti-inflammatory related mRNA was measured and normalized to that of the housekeeping gene, showing that treatment with the cells promoted the infiltration of endothelial cells and differentiation of M1 and M2 macrophages. In conclusion, wound healing in a third-degree burn injury model can be accurately analyzed using the optimized housekeeping gene.