Fig. 7.

The combined use of Tideglusib and EGF accelerates wound healing in aged skin. We generated 10 mm full-thickness cutaneous wounds on the backs of 23 M rats, and animals were randomly divided into four groups that received a total 200 μL drug (PBS, 20 μM Tideglusib, 10 μg/mL EGF, or combined use of Tideglusib and EGF) sprayed evenly on the wound everyday post wounding. The blue fenestrated sheet has a diameter of 12 mm and is used as a reference. N = 6. *P < 0.05 and **P < 0.01 were used to indicate the difference between the control group and the other groups. #P < 0.05, ##P < 0.01 were used to indicate the difference between the combination therapy group and the other groups. a Gross view of wounds with different treatments post-wounding. b 1 mm epidermis samples from the wound margin of 23 M SD rats were analyzed by Western Blot. N = 6. c Schematics depict the re-epithelialization process in young and aged animals. Owing to the decreased expression of EGFR, self-secreted or externally administered EGF could not effectively bind to its membrane receptor EGFR and thus cannot effectively induce sufficient phosphorylation of EGFR. Therefore, aged skin exhibits reduced PI3K/Akt pathway activity, lower proliferation capacity and higher levels of apoptosis. While wounds of young animals heal, the process is delayed in aged skin and could not be effectively restored by EGF