A time-course analysis of mRNA expression during injury healing in human dermal injuries.

The determination of dermal injury age is important in forensic practice. It helps answer questions that are important to an investigation such as the timing of the injury and incident, the order of infliction (where there is more than one injury), the survival time after injury (post-infliction interval) and the relation of the injury to the incident. Despite the importance of injury age determination, there currently exists no reliable method to estimate dermal injury age. In this study, the expression of the following 14 mRNAs was studied in human dermal injuries and their usefulness in the estimation of human dermal injury age was evaluated: dual specificity phosphate 1 (DUSP1), interleukin 7 (IL7), vascular cell adhesion molecule 1, tenascin C, cluster of differentiation 14, interleukin 6, tumour necrosis factor alpha (TNFα), interleukin 1beta (IL1β), chymase 1 (CMA1), collagen type III alpha I, interleukin 2, collagen type I alpha I, collagen type I alpha II and vascular endothelial growth factor A (VEGFA). DUSP1, IL7, TNFα and VEGFA showed an initial decrease in expression during the early stages followed by an increase in expression towards the middle and late phases. IL1β and CMA1 expression was limited to specific time points. The remaining markers either showed inconsistent expression or were undetected in our samples. The expression patterns of the detected markers suggest they have potential to predict injury age, especially during the initial stages of injury healing, if used in combination with one another.