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Although thioredoxin-interacting protein (TXNIP) is involved in a variety of biologic functions, the contribution of endothelial TXNIP has not been well defined. To investigate the endothelial function of TXNIP, we generated a TXNIP knockout mouse on the Cdh5-cre background (TXNIP fl/fl cdh5 cre ). Control (TXNIP fl/fl ) and TXNIP fl/fl cdh5 cre mice were fed a high protein-low carbohydrate (HP-LC) diet for 3 mo to induce metabolic stress. We found that TXNIP fl/fl and TXNIP fl/fl cdh5 cre mice on an HP-LC diet displayed impaired glucose tolerance and dyslipidemia concretizing the metabolic stress induced. We evaluated the impact of this metabolic stress on mice with reduced endothelial TXNIP expression with regard to arterial structure and function. TXNIP fl/fl cdh5 cre mice on an HP-LC diet exhibited less endothelial dysfunction than littermate mice on an HP-LC diet. These mice were protected from decreased aortic medial cell content, impaired aortic distensibility, and increased plasminogen activator inhibitor 1 secretion. This protective effect came with lower oxidative stress and lower inflammation, with a reduced NLRP3 inflammasome expression, leading to a decrease in cleaved IL-1β. We also show the major role of TXNIP in inflammation with a knockdown model, using a TXNIP-specific, small interfering RNA included in a lipoplex. These findings demonstrate a key role for endothelial TXNIP in arterial impairments induced by metabolic stress, making endothelial TXNIP a potential therapeutic target.-Bedarida, T., Domingues, A., Baron, S., Ferreira, C., Vibert, F., Cottart, C.-H., Paul, J.-L., Escriou, V., Bigey, P., Gaussem, P., Leguillier, T., Nivet-Antoine, V. Reduced endothelial thioredoxin-interacting protein protects arteries from damage induced by metabolic stress in vivo.

Whether approaches to chronically increase VEGF-A in the heart may have beneficial effects and prevent the development of heart failure, in part by improving cardiac perfusion, or whether this increase could have detrimental effects on cardiac performance in the aging heart, has not been tested yet. In this study, a genetic mouse model with a chronic increase in VEGF-A in the heart is shown to have increased cardiac angiogenesis and develop cardiac hypertrophy with enhanced basal cardiac performance with age progression. However, in aged hearts, this increase in VEGF-A was associated with higher expression of fetal cardiac genes and reduced cardiac performance after β-agonistic stress, features consistent with pathologic cardiac hypertrophy. Expression of Nod-like receptor protein (NLRP)-3 was increased in the hearts of the mice, and its genetic inactivation prevented increased fetal cardiac gene expression and partially rescued the impaired cardiac performance after β-agonistic stimulation in aged hearts without reducing cardiac angiogenesis or hypertrophy. Thus, although a chronic increase in cardiac VEGF-A may improve cardiac perfusion, long-term upregulation of VEGF-A leads to reduced cardiac performance under stress, an effect that can be partially inhibited by NLRP3 inactivation. Targeting NLRP3 shifts the VEGF-A-induced cardiac hypertrophy from a pathologic toward a more physiologic hypertrophy.-Marneros, A. G. Effects of chronically increased VEGF-A on the aging heart.