Metabolic syndrome-associated murine aortic wall stiffening is associated with premature elastic fibers aging
Résumé
Type 2 diabetes (T2D) constitutes a major public health problem, and despite prevention efforts, this pandemic disease is 'one of the deadliest diseases in the world. In 2022, 6.7 million T2D patients died prematurely from vascular complications. Indeed, diabetes increases the risk of myocardial infarction or stroke eightfold. The identification of the molecular actors involved in the occurrence of cardiovascular complications and their prevention are therefore major axes. Our hypothesis is that factors brought into play during physiological aging appear prematurely with diabetes progression. Our study focused on the aging of the extracellular matrix (ECM), a major element in the maintenance of vascular homeostasis. We characterized the morphological and functional aspects of aorta, with a focus on the collagen and elastic fibers of diabetic mice aged from 6 months to non-diabetic mice aged 6 months and 20 months. The comparison with the two non-diabetic models (young and old) highlighted an exacerbated activity of proteases, which could explain a disturbance in the collagen accumulation and an excessive degradation of elastic fibers. Moreover, the generation of circulating elastin-derived peptides reflects premature aging of the ECM. These extracellular elements contribute to the appearance of vascular rigidity, often the origin of pathologies such as hypertension and atherosclerosis. In conclusion, we show that diabetic mice aged 6 months present the same characteristics of ECM wear as those observed in mice aged 20 months. This accelerated aortic wall remodeling could then explain the early onset of cardiovascular diseases and, therefore, the premature death of DT2 patients.