Schlafen5, regulated by the AP-1 family transcription factor c-Fos, affects diabetic wound healing through modulating PI3K/Akt/NRF2 axis.

Abstract

Diabetic ulcers (DUs) present significant physical and psychological challenges to patients, while placing a significant economic burden on healthcare systems. Promoting the blood vessel regeneration is critical for ensuring the delivery of essential nutrients and oxygen to the injured area, thereby supporting the healing process. To gain insight into the complex molecular mechanisms that drive DUs healing, we performed a comprehensive analysis of single-cell transcriptomic data from healing and non-healing DU states. This analysis revealed a key role of Schlafen5 (SLFN5) signal in modulating key healing processes. SLFN5, a protein known to regulate cellular processes like migration, invasion, inflammation, and cell death, emerged as an important player. Yet, although it is prominent, the specific function of SLFN5 in diabetic skin wounds remained unclear. Our study discovered a marked elevation of SLFN5 levels in endothelial cells within DUs and its suppression notably mitigates the oxidative stress and endoplasmic reticulum stress (ERS)-mediated cell death pathways, including pyroptosis and apoptosis. This finding implies that excessive SLFN5 activity might obstruct wound closure by intensifying cellular stress reactions. Upon further investigation, we found that the antioxidant and cytoprotective effects were mediated through enhanced NRF2 activity, facilitated by the PI3K/Akt signaling pathway. Moreover, our investigation identified that c-Fos as a pivotal transcription factor governing SLFN5 transcription during the development of DUs, offering valuable insights into the regulation of SLFN5 expression. In diabetic mice model, SLFN5 knockdown accelerating wound healing, which was intervened by PI3K/Akt inhibitor. These results hold significant therapeutic potential, indicating that targeting SLFN5 may represent a novel and effective strategy for improving wound healing outcomes in patients with DUs.