Despite significant advancements in therapies, heart failure (HF) remains a major health challenge. Women, who are underrepresented in HF research, are particularly in need of effective treatments. B-vitamins are a promising and cost-effective option for improving cardiac function. Our study aimed to investigate the sex-specific effects of B-vitamin supplementation on HF with reduced ejection fraction in mice. Male and female mice underwent transverse aortic constriction (TAC) to induce pressure overload. Four weeks post-TAC, mice were randomized to receive either a standard or a vitamin B-enriched (VitB) diet. We found that in females, but not in males, VitB 1) extended survival, 2) slowed down the decrease in ejection fraction (EF), and 3) improved left ventricular morphology. The observed benefits in females were associated with evidence of improved cardiac and lung fibrosis and lower inflammation. In contrast, in males, VitB treatment did not reduce cardiac and lung fibrosis, whereas inflammation remained active in the myocardium. Regarding the circulating lipidome, disturbances were normalized in females with a specific enrichment in long-chain and polyunsaturated triglycerides (TGs) in response to VitB. Conversely, in males, lipidomic alterations remained under VitB treatment and were characterized by the accumulation of shorter and saturated TG in the circulation and myocardium. These data reveal a sex-specific response to VitB supplementation in HF in the context of pressure overload and point to a differential lipidomic remodeling that is only favorable in females.NEW & NOTEWORTHY This study explores the sex-specific effects of B-vitamin supplementation on heart failure with reduced ejection fraction in mice subjected to pressure overload. Our study found that B-vitamins improved survival rates, cardiac function, and reduced fibrosis in female mice, with favorable lipidomic remodeling characterized by an increase in polyunsaturated triglycerides. In contrast, male mice exhibited persistent inflammation, fibrosis, and unfavorable lipidome remodeling despite the B-vitamin supplementation. These findings underscore the sex-specific benefits of B-vitamins in heart failure, suggesting their potential therapeutic value for women, who remain underrepresented in cardiovascular research.

Background: Heart failure (HF) is a global health problem requiring more effective therapeutic alternatives. While HF involves disturbances in cardiac metabolism associated with lipidomic remodeling, there is a lack of approaches to specifically target cardiac metabolism. Recently, it has been shown in murine models of HF, that the use of nicotinamide riboside (vitamin B3) alone or the combination of B9 and B12 vitamins, before the development of HF, improved cardiac metabolism and function. Our hypothesis is that the combination of B3, B9 and B12 vitamins, used when HF is declared, will improve lipid metabolism, cardiac function and survival. The aim of this study is to evaluate the curative benefit of a synthetic diet enriched with the combination of these three vitamins (VitB) in a murine model of HF with reduced ejection fraction (EF). Method: Pressure overload was induced by constriction of the transverse aorta (TAC) in male and female mice. After 4 weeks, TAC mice reaching a pressure gradient of 60 mmHg, an increased left ventricle mass >30% and a reduced EF >10%, were randomized to a VitB-enriched diet or not. Results: In females, VitB improved survival and cardiac hypertrophy (-24%, p<0.05) as well as EF (+22%, p<0.01). We also observed a reduction of cardiac fibrosis emphasized by a significant decrease expression of collagen 1a and 3 (-30% and -19% respectively) and hydroxyproline concentration (-32%, p<0.01). No benefit was observed in males in terms of survival, cardiac function and fibrosis. Untargeted mass spectrometry (MS)-based lipidomics on plasmas at 8 weeks of treatment showed a decrease in several individual triglycerides (TG from 43 to 48 %; p<0.05) in TAC females that were normalized by VitB. In contrast, in TAC males, most of the annotated TGs were increased (from ̴35 to 210%; p<0.05), a profile exacerbated upon VitB treatment. MSMS identification of TG side chains revealed a differential profile in terms of fatty acid composition according to sex and treatment. In VitB females, longer and polyunsaturated TGs (53 to 60C; 5 to 12 double bonds) were significantly increased (1.6- to 2.1-fold) while, in VitB males, the increased TGs (1.2- to 5.2-fold) were shorter (24C to 48C) and saturated (no double bonds). Conclusion: Our study pointed out a sexual dimorphism in the response to VitB treatment in HF in favor of females and implying a lipidomic remodeling promoting cardioprotective polyunsaturated TGs. European Research Area Network on Cardiovascular Diseases, Canadian Institutes of Health Research, Fonds de recherche du Québec - Santé. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Our pilot study suggests a sexual dimorphism in the response to BVit treatment in experimental HF. Indeed, the benefit of BVit treatment is only shown in females with a delay in the mortality rate associated with improved cardiac function and normalisation of lipid disturbances. To explore and understand the mechanisms underlying this sexual dimorphism, the lipid profile hypothesis appears as a relevant avenue to explore in the future.

Plasmalogens belong to a subclass of phospholipids called ether lipids. The peroxisome synthesize these lipids and involve the limiting AGPS enzyme. In addition, mutations in the Agps gene are associated with cardiac manifestations. We hypothesized that decreased plasmalogens in cells negatively affect mitochondrial function and cell survival. We aimed to evaluate the metabolic and functional consequences of plasmalogens deficiency in a cardiomyoblastic cell line (H9c2 cells) modified using a CRISPR-Cas9 strategy targeting the Agps gene. We characterized this cell line using qPCR and immunoblotting to explore the influence on markers related to mitochondrial function [biogenesis, fatty acid metabolism (FA)], endoplasmic reticulum (ER) stress and apoptosis. AGPS reduction was validated at the gene (−58%) and protein (−78%) level, and is associated with decreased plasmalogens (−76%) that we analysed using mass spectrometry. This deficiency leaded to mitochondrial perturbations as revealed by changes on the expression of genes involved in biogenesis: Pgc-1α and ß (−27%; −61%), dynamics: Opa1 and Mff (−15%) as well as in the use of FA: Cd36 and Cpt1 (−52%; −51%) and in the oxidation of FA: Vlcad and Lcad (−22%; −13%). Consistently, using mass spectrometry, we observed decreased acylcarnitines (̴75%) used as markers of mitochondrial FA metabolism. This is accompanied with signs of increased ER stress and apoptosis as suggested by the increase in Chop gene expression (+31%) and the decreased uncleaved form of the Caspase-3 protein (−32%), respectively. Finally, we were able to normalize the levels of plasmalogen in our cells using alkylglycerols. Collectively, these results demonstrate that lowering plasmalogens affects mitochondrial function and cell stress in H9c2 cells. The normalisation of plasmalogens using alkylglycerols is encouraging to further characterize their metabolic and functional benefits.

Defects in fatty acid (FA) utilization have been well described in group 1 pulmonary hypertension (PH) and in heart failure (HF), yet poorly studied in group 2 PH. This study was to assess whether the metabolomic profile of patients with pulmonary hypertension (PH) due HF, classified as group 2 PH, differs from those without PH. We conducted a proof-of-principle cross-sectional analysis of 60 patients with chronic HF with reduced ejection fraction and 72 healthy controls in which the circulating level of 71 energy-related metabolites was measured using various methods. Echocardiography was used to classify HF patients as noPH-HF (n = 27; mean pulmonary artery pressure [mPAP] 21 mmHg) and PH-HF (n = 33; mPAP 35 mmHg). The profile of circulating metabolites among groups was compared using principal component analysis (PCA), analysis of covariance (ANCOVA), and Pearson’s correlation tests. Patients with noPH-HF and PH-HF were aged 64 ± 11 and 68 ± 10 years, respectively, with baseline left ventricular ejection fractions of 27 ± 7% and 26 ± 7%. Principal component analysis segregated groups, more markedly for PH-HF, with long-chain acylcarnitines, acetylcarnitine, and monounsaturated FA carrying the highest loading scores. After adjustment for age, sex, kidney function, insulin resistance, and N-terminal pro-brain natriuretic peptide (NT-proBNP), 5/15 and 8/15 lipid-related metabolite levels were significantly different from controls in noPH-HF and PH-HF subjects, respectively. All metabolites for which circulating levels interacted between group and NT-proBNP significantly correlated with NT-proBNP in HF-PH, but none with HF-noPH. FA-related metabolites were differently affected in HF with or without PH, and may convey adverse outcomes given their distinct correlation with NT-proBNP in the setting of PH.