Project description:Heart failure affects 2–3% of adult Western population. Prevalence of heart failure with preserved left ventricular (LV) ejection fraction (HFpEF) increases. Studies suggest HFpEF patients to have altered myocardial structure and functional changes such as incomplete relaxation and increased cardiac stiffness. We hypothesised that patients undergoing elective coronary bypass surgery (CABG) with HFpEF characteristics will show distinctive gene expression compared to patients with normal LV physiology. Myocardial biopsies for mRNA expression analysis were obtained from sixteen patients with LV ejection fraction ≥ 45%. Five out of 16 patients (31%) had echocardiographic characteristics and increased NTproBNP levels indicative of HFpEF and this group was used as HFpEF proxy, while 11 patients had Normal LV physiology. Utilising principal component analysis, the gene expression data clustered into two groups, corresponding to HFpEF proxy and Normal physiology, and 743 differentially expressed genes were identified. The associated top biological functions were cardiac muscle contraction, oxidative phosphorylation, cellular remodelling and matrix organisation. Our results also indicate that upstream regulatory events, including inhibition of transcription factors STAT4, SRF and TP53, and activation of transcription repressors HEY2 and KDM5A, could provide explanatory mechanisms to observed gene expression differences and ultimately cardiac dysfunction in the HFpEF proxy group. <br> Sequencing data from clinical patients fall under GDPR regulations of sharing of personal data and will be made available through EGA-SE.
Project description:Background: Heart failure with preserved ejection fraction (HFpEF) constitutes more than half of all heart failure but has few effective therapies. Recent human myocardial transcriptomics and metabolomics have revealed major differences between HFpEF, HF with reduced EF (HFrEF), and controls. How this translates at the protein level is currently unknown. Methods: Myocardial tissue from patients with HFpEF and non-failing donor controls was analyzed by data-dependent (DDA, n=10 HFpEF, n=9 controls) and data-independent (DIA, n=44 HFpEF, n=5 controls) mass spectrometry-based proteomics. Previously reported myocardial proteomic data from end-stage HFrEF and controls were also used. Differential protein expression analysis, machine learning and pathway enrichment were integrated with clinical characteristics and myocardial transcriptomics. Results: DDA-MS proteomics identified 88 significantly upregulated and 248 down-regulated proteins in HFpEF vs controls, out of 1996 identified proteins. Principal component analysis of DDA-MS proteomics found HFpEF was separated into 2 sub-groups: one being similar to controls the other quite disparate. Top proteins contributing to the separation of HFpEF subgroups were enriched in actin/myosin binding, regulation of DNA replication/repair, transcription, and translation. Downregulated proteins in HFpEF vs controls were enriched in pathways related to ribosome structure, transmembrane transporters, metabolic enzymes, and oxidative phosphorylation (OxPhos) proteins. Enriched pathways for proteins upregulated in HFpEF related to actin and phospholipid binding, growth factor signaling, kinase regulation, and glycolysis. Ingenuity pathway analysis predicted downregulation of protein translation, mitochondrial function, and glucose and fat metabolism in HFpEF. OxPhos gene (increased) versus protein (decreased) expression was discordant in HFpEF. The second DIA proteomic analysis also yielded two HFpEF sub-groups; the one most different from controls also having reduced OxPhos and protein translation pathways. A higher proportion of these patients also had severe obesity. Conclusions: Integrative proteomics, transcriptomics, and pathway analysis supports a translational defect particularly involving mitochondrial, ribosomal and protein translation proteins in HFpEF. Patients with more distinct proteomic signatures from control were more often very obese. The results support therapeutic efforts targeting metabolism, mitochondrial function, and protein translation in this subgroup.
Project description:In this study, we compared the expression profiles of circulating miRNAs in blood samples from controls and patients with heart ailment. Subject with no past history of heart failure/disease are considered as controls. The patients were classified according to the percentage of left ventricular ejection fraction. Patients were grouped as heart failure with reduced (hfREF) and preserved (hfPEF) left ventricular ejection fraction. Employing miRNA microarray, we identified 'signature miRNAs' in peripheral blood samples that distinguished Heart failure from the non-heart failure controls, as well as those of hfREF and hfPEF groups.
Project description:Heart failure (HF) impacts 2-3% of adults in the West, with prevalence rising with age. This condition, leading to high mortality and morbidity, increasingly involves HF with preserved left ventricular (LV) ejection fraction (HFpEF) in the aging population, having a similar stable prognosis as HF with reduced LVEF (HFrEF). However, HFpEF lacks many evidence-based therapies, partly due to its distinct pathophysiology compared to HFrEF. Molecularly, heart failure shows distinct gene expression changes, indicative of varying diseases. Prior research, including our early report from the CABG-PREFERS study, shows gene expression differences in HFpEF and normal hearts, although studies are limited. Both HFpEF and HFrEF patients exhibit altered LV myocardial structure and function, often affecting the right ventricle (RV) secondarily. In the CABG-PREFERS sub-study, part of the PREFERS programme, we classified patients by LVEF, structural abnormalities, diastolic dysfunction, and NT-proBNP levels into HFpEF physiology, HFrEF physiology, and normal LV function groups. Our hypothesis suggests gene expression and transcriptomic variations between LV and RV, and between HFpEF, HFrEF, and normal LV function, providing insights into different HF phenotypes and guiding future therapies.
Project description:Left ventricular (LV) diastolic dysfunction is a hallmark of Heart Failure with preserved Ejection Fraction (HFpEF), an escalating global health challenge. We demonstrated selective depletion of the oxidized form of nicotinamide adenine dinucleotide (NAD+) and the rate-limiting enzyme of the NAD+ biosynthetic salvage pathway, nicotinamide phosphoribosyltransferase (NAMPT), in human myocardium with LV diastolic dysfunction. We showed that NAD+ can be replenished in human myocardium with diastolic impairment ex vivo, despite reduced NAMPT expression. In a murine model of HFpEF [a combination exposure to high-fat diet (HFD) and L-NG-Nitro arginine methyl ester (L-NAME)], we compared the benefits of NAD+ precursor supplementation versus dietary intervention. We tested NAD+ repletion by nicotinamide riboside (NR) supplementation using two clinically-relevant strategies: 1) Prophylactic NR repletion before HFpEF onset, and 2) Therapeutic NR repletion after the development of HFpEF. We found that dietary intervention (replacement of HFD and L-NAME with healthy diet) restored myocardial insulin-dependent glucose uptake and glycolysis but did not rescue HFpEF. In contrast, both NAD+ repletion strategies prevented or rescued HFpEF, respectively, plausibly due to restoration of myocardial iron homeostasis, recoupling of glycolysis to the TCA cycle, and upregulation of antioxidant defense.
Project description:In this study the authors used systems biology to define progressive changes in metabolism and transcription in a large animal model of heart failure with preserved ejection fraction (HFpEF). Transcriptomic analysis of cardiac tissue, 1 month post-banding, revealed loss of electron transport chain components, and this was supported by changes in metabolism and mitochondrial function, altogether signifying alterations in oxidative metabolism. Established HFpEF, 4 months post-banding, resulted in changes in intermediary metabolism with normalized mitochondrial function. Mitochondrial dysfunction and energetic deficiencies were noted in skeletal muscle at early and late phases of disease, suggesting cardiac-derived signaling contributes to peripheral tissue maladaptation in HFpEF. Collectively, these results provide insights into the cellular biology underlying HFpEF progression.
Project description:Immune cell activation in heart failure is poorly understood. We profiled circulating leukocytes in humans with heart failure with preserved ejection fraction and non heart failure controls to identify novel changes associated with HFpEF diagnosis
Project description:Although the prevalence of heart failure with preserved ejection fraction (HFpEF) is increasing, evidence-based therapies for HFpEF are rare, likely due to an incomplete understanding of this disease. This study sought to identify the cardiac-specific features of protein and phosphoprotein in a murine model of HFpEF using mass spectrometry. HFpEF mice developed moderate hypertension, left ventricle (LV) hypertrophy, lung congestion and diastolic dysfunction. Proteomics analysis of the LV tissue showed that 897 proteins were differentially expressed between HFpEF and Sham mice. We observed abundant changes in sarcomeric proteins, mitochondrial-related proteins, and NAD-dependent protein deacetylase sirtuin-3 (SIRT3). Upregulated pathways by GSEA analysis were related to immune modulation and muscle contraction, while downregulated pathways were predominantly related mitochondrial metabolism. Western blot analysis validated SIRT3 downregulated cardiac expression in HFpEF. Phosphoproteomics analysis showed that 72 phosphopeptides were differentially regulated between HFpEF and sham LV. Aberrant phosphorylation patterns mostly occurred in sarcomere proteins and nuclear-localized proteins associated with contractile dysfunction and cardiac hypertrophy. Seven aberrant phospho-sites were observed at the z disk binding region of titin. While total titin cardiac expression remained unaltered, its stiffer N2B isoform was significantly increased in HFpEF. Thus, these results show profound changes in proteins related to mitochondrial metabolism and function and the cardiac contractile apparatus in HFpEF. We propose that SIRT3 plays a key role and may be a target for drug development in HFpEF.
Project description:Patients with heart failure with preserved ejection fraction (HFpEF) often have an unfavorable cardiometabolic profile, and obesity-related HFpEF has become a well-recognized HFpEF sub-phenotype. Targeting this unfavorable cardiometabolic profile may therefore represent a rational treatment strategy. The glucagon-like peptide-1 receptor agonist (GLP1-RA) semaglutide has been shown to induce significant weight loss and to improve cardiovascular outcomes. In this study, we investigated the cardiometabolic effects of semaglutide in a representative mouse model of HFpEF and compared it to the effects of weight loss by caloric restriction.