Abstract: Objective To investigate the changes of phospho-JNK(p-JNK) during the incised wound healing of the skin in mice and to explore the rule of the time-dependent change of p-JNK in wound age determination.Methods The changes of p-JNK expression in incised skin wound were detected by immunohistochemistry and Western blot.Results There was a minimal baseline staining of p-JNK in control mouse skin.Changes of p-JNK expression were mainly detectable in neutrophils in the wound specimens from 3 hours to 12 hours after injury.Afterwards,the p-JNK positive cells were mostly mononuclear cells and fibroblasts between post-injury day 1 and day 5,whereas the p-JNK positive cells were mostly fibroblasts between post-injury day 7 and day 14.Morphometrically,the ratio of the p-JNK positive cells to the total increased gradually in the wound specimens from 3 hours to day 1,and maximized at day 1 with a slight decrease from post-injury day 3 to day 5.The ratio showed a second peak in the specimens of day 7,and then decreased gradually from post-injury day 10 to day 14.The changes of p-JNK expression were observed throughout the wound healing stages by Western blot as well,with a peak expression occurring between 12 hour and day 3 after injury.Conclusion p-JNK may play a pivotal role in inducing apoptosis of neutrophils,mononuclear cells,and fibroblasts during skin wound healing and meanwhile,p-JNK may be a potentially useful marker for wound age determination.

Key words: forensic pathology, wounds and injures, wound healing, JNK mitogen-activated kinases, wound age determination