Mitochondrial Dysfunction in Endothelial Cells Drives Greater Vascular Impairment in Females with Diabetes-Associated Peripheral Artery Disease

Background: Women with peripheral artery disease (PAD) experience poorer clinical outcomes than men, particularly in the setting of diabetes. However, the mechanistic basis for these sex-specific disparities remains unclear. Methods: Here, we investigated endothelial cell (EC) function(s) in diabetes-associated PAD, with a focus on sex differences. Limb tissues from patients with diabetes and chronic limb-threatening ischemia (CLTI) undergoing amputation and a diabetes mouse model of hindlimb ischemia (HLI) were assessed for vasodilatory capacity, angiogenesis, oxidative stress and changes to expression of mitochondrial complex genes. ECs exposed to a diabetic environment in vitro were assessed for mitochondrial function. The therapeutic potential of the mitochondrial-targeted antioxidant MitoQ was investigated. Results: ECs from females with diabetes-associated PAD have altered responses compared to males. Specifically, limb vessels and skeletal muscle from females exhibit reduced arterial relaxation, angiogenesis and increased oxidative stress in response to HLI in mice, and in tissues from patients. Single-cell RNA sequencing of murine limbs revealed marked suppression of EC mitochondrial complex genes in females with diabetes. Female human ECs exposed to high glucose had reduced respiration, reduced expression of mitochondrial genes and increased oxidative stress. Remarkably, MitoQ restored arterial relaxation and the angiogenic response in female diabetes-associated PAD. Conclusion: Our findings uncover a striking sex-specific vulnerability in microvascular and EC health in diabetes-associated PAD, oxidative stress and mitochondrial dysfunction. These results highlight the need for sex-specific therapeutic strategies in diabetic PAD, which might include mitochondrial targeted antioxidant strategies.