Cuproptosis, a potential target for the therapy of diabetic critical limb ischemia

Diabetic patients are considered as the high risk population to develop critical limb ischemia (CLI), a peripheral vascular disease (PVD) resulted from atherosclerosis. Cuproptosis is a novel copper-dependent cell death that has shown the regulatory role in diabetes, while its effect on diabetic CLI has not been explored yet. In this study, Diabetic CLI mice was induced by femoral artery ligation (FAL) on diabetic mice. Endothelial injury in diabetic CLI was mimicked in human microvascular endothelial cells (HMEC-1) via the induction with high glucose (HG) and nutrient deprivation (ND). Besides, copper chelator Ammonium Tetrathiomolybdate (TM), which has shown the anti-cuproptosis property, was administrated to explore its potential effects on diabetic CLI mice and HG/ND-induced HMEC-1 cells. Strikingly, obvious cuproptosis was found in the gastrocnemius muscles of diabetic CLI mice and HG/ND-induced HMEC-1 cells, as evidenced by the copper overload and dysregulated cuproptosis-related proteins (such as Fe-S cluster proteins, copper exporter ATP7A, and copper importer SLC31A1). More importantly, TM protected against the hindlimb ischemic damages in diabetic CLI mice and alleviated cuproptosis-associated cell deaths in HG/ND-induced HMEC-1 cells. In summary, this study indicates the involvements of cuproptosis in diabetic CLI, and provides novel insights into copper chelator TM on diabetic CLI therapy.