ATF3 mRNA, but not BTG2, as a possible marker for vital reaction of skin contusion.

The detection of vitality of wounds, especially when the wounds are inflicted very close to the time of death, is one of the most challenging issues in forensic pathology. This study investigated expression levels of ATF3 and BTG2 in mouse and human skin wounds. Protein levels examined by western blot showed that there was no significant change in ATF3 and BTG2 between wounded and intact skins. However, mRNA levels demonstrated higher expression of ATF3 and BTG2 in ante-mortem contused mouse skins, compared with the intact and postmortem contused skins. Increased ATF3 and BTG2 in the level of mRNA could also be detected until 96h and 48h after death, respectively. Human wounded skin samples from forensic autopsy cases were also examined. Increased ATF3 mRNA levels were detected until 48h after autopsy in 5 of 6 cases. However, no differences were observed between wounded and intact skins for BTG2. These findings suggest that the detection of mRNA levels of ATF3, but not BTG2, can be considered as a potential marker for vital reaction of skin contusion. Postmortem human samples should be used in order to validate the availability of markers screened by animal experiment.