AMPK activation eliminates senescent cells in diabetic wound by inducing NCOA4 mediated ferritinophagy.

Abstract

Diabetic wounds are one of the long-term complications of diabetes, with a disordered microenvironment, diabetic wounds can easily develop into chronic non-healing wounds, which can impose a significant burden on healthcare. In diabetic condition, senescent cells accumulate in the wound area and suppress the wound healing process. AMPK, as a molecule related to metabolism, has a close relationship with aging and diabetes. The purpose of this study was to investigate the effects of AMPK activation on wound healing and explore the underlying mechanisms. AMPK activator A769662 was topically applied in wound models of diabetic mice. Alterations in the wound site were observed and analyzed by immunohistochemistry. The markers related to autophagy and ferritinophagy were analyzed by western blotting and immunofluorescence staining. The role of AMPK activation and ferritinophagy were also analyzed by western blotting. Our results show that AMPK activation improved diabetic wound healing and reduced the accumulation of senescent cells. Intriguingly, we found that AMPK activation-induced ferroptosis is autophagy-dependent. We detected that the level of ferritin had deceased and NCOA4 was markedly increased after AMPK activation treatment. We further investigated that NCOA4-mediated ferritinophagy was involved in ferroptosis triggered by AMPK activation. Most importantly, AMPK activation can reverse the ferroptosis-insensitive of senescent fibroblast cells in diabetic mice wound area and promote wound healing. These results suggest that activating AMPK can promote diabetic wound healing by reversing the ferroptosis-insensitive of senescent fibroblast cells. AMPK may serve as a regulatory factor in senescent cells in the diabetic wound area, therefore AMPK activation can become a promising therapeutic method for diabetic non-healing wounds.