[The time-dependent changes of phospho-JNK expression during the skin incised wound healing in mice].

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.