Chronic heart failure with reduced EF: A decade of major pharmacological innovations

The effect of high-fiber diet based on gut microbiota in patients with chronic heart failure

This research explored the effect of a high-fiber diet based on gut microbiota on patients with chronic heart failure (HF). Patients with chronic HF, who had undergone a dietary survey indicating a daily dietary fiber intake of less than 15 g/day, were divided into the control and study groups (n = 50). In addition to conventional heart failure treatment, the study group received dietary guidance, while the control group did not receive any dietary guidance and maintained their usual low-fiber dietary habits. After 1 yr intervention, the daily dietary fiber intake, abundance of gut microbiota, plasma trimethylamine N-oxide (TMAO), albumin (ALB), prealbumin (PA), transferrin (TF), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), left ventricular ejection fraction (LVEF), left ventricular end-diastolic index (LVEDVI), and left ventricular end-systolic volume index (LVESVI), Barthel index (BI), and 6 min walking distance (6 MWD) were compared. After the intervention, in both groups, the daily dietary fiber intake increased and the abundance of Firmicutes, Proteobacteria, Actinobacteria, and Fusobacteria decreased and that of Bacteroides increased; the plasma TMAO decreased; serum ALB, PA, and TF levels increased; serum CRP, TNF-α, IL-6, and IL-8 levels decreased, and the change was greater in the study group; LVEF elevated, LVEDVI and LVESVI reduced, and the differences between both groups were not significant; BI and 6 MWD elevated, and the study group was higher than the control group. High-fiber diet positively regulates the composition of gut microbiota, nutritional status, and microinflammatory level in patients with chronic HF, thereby improving patients' quality of life.NEW & NOTEWORTHY Traditional heart failure (HF) treatment primarily focuses on medications and surgery, whereas this study explores the improvement effects of a diet high in dietary fiber on patients with chronic HF from the perspective of gut microbiota, providing a new perspective for HF treatment.

VPO1 Promotes Programmed Necrosis of Cardiomyocytes in Rats with Chronic Heart Failure by Upregulating CYLD

BACKGROUND

Chronic heart failure (CHF) is a serious cardiovascular condition. Vascular peroxidase 1 (VPO1) is associated with various cardiovascular diseases, yet its role in CHF remains unclear. This research aims to explore the involvement of VPO1 in CHF.

METHODS

CHF was induced in rats using adriamycin, and the expression levels of VPO1 and cylindromatosis (CYLD) were assessed. In parallel, the effects of VPO1 on programmed necrosis in H9c2 cells were evaluated through cell viability assays, lactate dehydrogenase (LDH) level measurements, and analysis of receptor-interacting protein kinase 1/receptor-interacting protein kinase 3/mixed lineage kinase domain-like protein (RIPK1/RIPK3/MLKL) pathway-related proteins. The impact of CYLD on RIPK1 protein stability and ubiquitination was also investigated, along with the interaction between VPO1 and CYLD. Additionally, cardiac structure and function were assessed using echocardiography, Hematoxylin-eosin (HE) staining, Masson staining, and measurements of myocardial injury-related factors, including N-terminal prohormone of brain natriuretic peptide (NT-proBNP), Aspartate aminotransferase (AST), LDH, and creatine kinase-myocardial band (CK-MB).

RESULTS

VPO1 expression was upregulated in CHF rats and in H9c2 cells treated with adriamycin. In cellular experiments, VPO1 knockdown improved cell viability, inhibited necrosis and the expression of proteins associated with the RIPK1/RIPK3/MLKL pathway. Mechanistically, VPO1 promoted cardiomyocyte programmed necrosis by interacting with the deubiquitinating enzyme CYLD, which enhanced RIPK1 ubiquitination and degradation, leading to activation of the RIPK1/RIPK3/MLKL signaling pathway. At animal level, overexpression of CYLD counteracted the cardiac failure, cardiac hypertrophy, myocardial injury, myocardial fibrosis, and tissue necrosis caused by VPO1 knockdown.

CONCLUSIONS

VPO1 exacerbates cardiomyocyte programmed necrosis in CHF rats by upregulating CYLD, which activates the RIPK1/RIPK3/MLKL signaling pathway. Thus, VPO1 may represent a potential therapeutic target for CHF.