Defective NCOA4-dependent ferroptosis in senescent fibroblasts retards diabetic wound healing

Cellular senescence describes a state of permanent proliferative arrest in cells. Studies have demonstrated that diabetes promotes the pathological accumulation of senescent cells, which in turn impairs cell movement and proliferation. Historically, senescence has been perceived to be a detrimental consequence of chronic wound healing. However, the underlying mechanism that causes senescent cells to remain in diabetic wounds is yet to be elucidated. Ferroptosis and ferritinophagy observed in diabetes are due to iron metabolism disorders, which are directly associated with the initiation and progression of diabetes. Herein, we reveal that senescent fibroblasts in diabetic wounds are resistant to ferroptosis and that impaired ferritinophagy may be a contributing cause. Further, the expression of NCOA4, a key factor that influences ferritinophagy, is decreased in both diabetic wound tissue and high glucose-induced senescent fibroblasts. Moreover, NCOA4 overexpression could render senescent fibroblasts more vulnerable to ferroptosis. A faster wound healing process was also linked to the induction of ferroptosis. Thus, resistance to ferroptosis impedes the removal of senescent fibroblasts; promoting ferritinophagy could reverse this process, which may have significant implications for the management of diabetic wounds.