Mitochondria-targeted hydrogen sulfide donor reduces atherogenesis by reprogramming macrophages and increasing UCP1 expression in vascular smooth muscle cells

Abstract Aims Atherosclerosis is a leading cause of morbidity and mortality in the Western countries. A growing body of evidence points to the role of mitochondrial dysfunction in the pathogenesis of atherosclerosis. Recently, it has been shown that mitochondrial hydrogen sulfide (H 2 S) can complement the bioenergetic role of Krebs cycle leading to improved mitochondrial function. However, controlled, direct delivery of H 2 S to mitochondria was not investigated as a therapeutic strategy in atherosclerosis. Therefore, the aim of our study was to comprehensively evaluate the influence of prolonged treatment with mitochondrial H 2 S donor AP39 on the development of atherosclerotic lesions in apolipoprotein E knockout (apoE -/- ) mice. Results Our results indicated that AP39 reduced atherosclerosis in apoE -/- mice and stabilized atherosclerotic lesions through decreased total macrophage content and increased collagen depositions. Moreover, AP39 reprogrammed macrophages from proinflammatory M1 to anti-inflammatory M2 in atherosclerotic lesions. It also upregulated pathways related to mitochondrial function, such as cellular respiration, fatty acid β-oxidation and thermogenesis while downregulated pathways associated with immune system, platelet aggregation and complement and coagulation cascades in the aorta. Furthermore, treatment with AP39 increased the expression of mitochondrial brown fat uncoupling protein 1 (UCP1) in vascular smooth muscle cells (VSMCs) in atherosclerotic lesions and upregulated mRNA expression of other thermogenesis-related genes in the aorta but not perivascular adipose tissue (PVAT) of apoE -/- mice. Finally, AP39 treatment decreased markers of activated endothelium and increased endothelial nitric oxide synthase (eNOS) expression and activation. Conclusions Taken together, mitochondrial H 2 S donor AP39 could provide potentially a novel therapeutic approach to the treatment/prevention of atherosclerosis.