A cocktail of B vitamins with nicotinamide riboside, folate and cobalamin preserves cardiac function and mitochondrial oxidative capacities in a mouse model of heart failure.
Despite a substantial therapeutic arsenal to treat patients affected by heart failure (HF), no treatment specifically targets alterations of cardiac energy metabolism and mitochondrial functions. Yet, these alterations are now well-known and their involvement in HF pathophysiology has been demonstrated for years. Based on the results of previous studies demonstrating the cardiac preventive effects of B vitamins when introduced before inducing cardiac pressure overload in mice, we investigated the efficacy of a diet supplemented with a B vitamin cocktail (B3, B9 and B12 (3VitB)) to restore energy metabolism and improve cardiac function in an animal model of established HF. Heart Failure was induced by transverse aortic constriction (TAC) in male and female C57Bl6N mice and 3VitB treatment was introduced four weeks later in animals meeting criteria of heart failure with restricted ejection fraction. A 20-week survival study showed a significant longer life expectancy in TAC males treated with Vit3B in comparison with TAC males fed with normal diet, and this was associated with a reduction in the over time TAC-induced alterations of ejection fraction, stroke volume, and systolic and diastolic left ventricular diameter. Although, these effects on survival and cardiac function were less clear in females due to their higher resistance to TAC, the Vit3B cocktail was beneficial in females as 8 weeks of treatment improved physical capacities and led to milder cardiomyocyte stress-induced hypertrophy in similar ways to those observed in males. In both sexes, 3VitB treated TAC mice exhibited higher mitochondrial oxidative capacities than TAC mice fed with normal diet. This was at least partly supported by the maintenance of the mitochondrial biogenesis process activation, demonstrated by the higher expression of genes such as Tfam and NRF1 protein level in 3VitB treated TAC groups. Interestingly, our results revealed sex-specificities not only in response to cardiac pressure overload but also in response to 3VitB treatment that acted through different mechanisms that involved AMPK in males and SIRT1 in females. Overall, this study demonstrated the efficacy of 3VitB to preserved cardiac function and energy metabolism in an established HF model, especially in males that are more sensitive to cardiac pressure overload. This confers credit to vitamin supplementations and to metabolic therapy as new strategies in the treatment of HF.