Cardiac Remodeling In Heart Failure Research Articles

CNOT6L deadenylase suppresses cardiac remodeling in heart failure through downregulation of tenascin-C mRNA.

Heart failure is rapidly increasing and is a growing burden on human health and economy in the world. The functional role of mRNA regulation in the pathogenesis of heart failure remains to be elucidated. CCR4-NOT complex is a multi-subunit protein complex that deadenylates mRNA, a process of exonuclease-mediated degradation of mRNA poly(A) tail. Here we show the cardiac protective roles of deadenylase subunit CNOT6L against cardiac stress. After 2 weeks of transverse aortic constriction (TAC)-induced pressure overload, expression of CNOT6L deadenylase subunit was significantly upregulated in the mouse hearts. When CNOT6L gene was genetically deleted, the mice exhibited marked decline of left ventricular contractility and enhancement of fibrosis at 2 weeks after TAC. Transcriptome analyses elucidated that CNOT6L targets tenascin-C mRNA, which stimulates tissue fibrosis and inflammation. CNOT6L deletion markedly upregulated tenascin-C expression in cardiac fibroblasts. Poly(A) tail length and luciferase reporter analyses revealed that CNOT6L catalyzes deadenylation of tenascin-C mRNA likely through interaction with the cis-element in its 3'-UTR. Double knockout of tenascin-C and CNOT6L ameliorated cardiac fibrosis and dysfunction in single CNOT6 knockout mice under TAC or chronic infusion of angiotensin II. Thus, CNOT6L deadenylase prevents the progression of heart failure through downregulation of the expression of tenascin-C in cardiac fibroblasts, implicating a potential therapeutic strategy of targeting mRNA deadenylation.

Fibroblast-derived miR-425-5p alleviates cardiac remodelling in heart failure via inhibiting the TGF-β1/Smad signalling.

The pathological activation of cardiac fibroblasts (CFs) plays a crucial role in the development of pressure overload-induced cardiac remodelling and subsequent heart failure (HF). Growing evidence demonstrates that multiple microRNAs (miRNAs) are abnormally expressed in the pathophysiologic process of cardiovascular diseases, with miR-425 recently reported to be potentially involved in HF. In this study, we aimed to investigate the effects of fibroblast-derived miR-425-5p in pressure overload-induced HF and explore the underlying mechanisms. C57BL/6 mice were injected with a recombinant adeno-associated virus specifically designed to overexpress miR-425-5p in CFs, followed by transverse aortic constriction (TAC) surgery. Neonatal mouse CFs (NMCFs) were transfected with miR-425-5p mimics and subsequently stimulated with angiotensin II (Ang II). We found that miR-425-5p levels were significantly downregulated in HF mice and Ang II-treated NMCFs. Notably, fibroblast-specific overexpression of miR-425-5p markedly inhibited the proliferation and differentiation of CFs, thereby alleviating myocardial fibrosis, cardiac hypertrophy and systolic dysfunction. Mechanistically, the cardioprotective actions of miR-425-5p may be achieved by targeting the TGF-β1/Smad signalling. Interestingly, miR-425-5p mimics-treated CFs could also indirectly affect cardiomyocyte hypertrophy in this course. Together, our findings suggest that fibroblast-derived miR-425-5p mitigates TAC-induced HF, highlighting miR-425-5p as a potential diagnostic and therapeutic target for treating HF patients.

Impact of SGLT2 inhibition on markers of reverse cardiac remodelling in heart failure: Systematic review and meta-analysis.

Several landmark randomized-controlled trials (RCTs) have demonstrated the efficacy of sodium-glucose co-transport 2 (SGLT2) inhibitors in reducing all-cause mortality, cardiovascular (CV) mortality and heart failure (HF) hospitalizations. Much interest surrounds their mechanism of action and whether they have direct effects on reverse cardiac remodelling. Therefore, we conducted a meta-analysis of placebo controlled RCTs evaluating the impact of SGLT2 inhibition on imaging derived markers of reverse cardiac remodelling in patients with HF. We performed a systematic review and meta-analysis in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) Statement and Cochrane Collaboration. Data interrogation of each major database including PubMed, EMBASE, MEDLINE and Cochrane Library was performed. RCTs evaluating HF patients >18years comparing SGLT2 inhibitor versus placebo-control were included. Outcome measures included left ventricular end-diastolic volume and volume index (LVEDV/LVEDVi), left ventricular end-systolic volume and volume index (LVSDV/LVSDVi), left ventricular ejection fraction (LVEF), left ventricular mass index (LVMi), left atrial volume index (LAVi) and left ventricular global longitudinal strain (LV GLS). Studies with an HF with preserved ejection fraction population were excluded from analysis of parameters, which would be significantly affected by baseline LVEF, such as volumes and LVEF. The mean difference and standard error were extracted from each study and a random effects model used pool the mean difference and standard error across studies. A pre-specified sub-group analysis was performed to stratify results according to imaging modality used (cardiac magnetic resonance imaging and echocardiography). This study is registered on PROSPERO: CRD42023482722. Seven randomized, placebo-controlled trials in patients with HF comprising a total population of 657 patients were included. Overall LVEF of included studies ranged from 29±8.0% to 55.5±4.2%. In studies included in analysis of HFrEF parameters, baseline LVEF ranged from 29±8% to 45.5±12%. Pooled data demonstrated SGLT2 inhibition, compared with placebo control, resulted in significant improvements in mean difference of LVEDV [-11.62ml (95% confidence interval, CI -17.90 to -5.25; z=3.67, P=0.0004)], LVEDVi [-6.08ml (95% CI -9.96 to -2.20; z=3.07; P=0.002)], LVESV [-12.47ml (95% CI -19.12 to -5.82; z=3.68; P=0.0002)], LVESVi [-6.02ml (95% CI -10.34 to -1.70; z=2.73; P=0.006)], LVM [-9.77g (95% CI -17.65 to -1.89; z=2.43; P=0.02)], LVMi (-3.52g [95% CI -7.04 to 0.01; z=1.96; P=0.05)] and LVEF [+2.54mL (95% CI 1.10 to 3.98; z=3.62; P=0.0005)]. No significant difference in GLS (n=327) [+0.42% (95%CI -0.19 to 1.02; P=0.18)] or LAVi [-3.25ml (95% CI -8.20 to 1.69; z=1.29; P=0.20)] was noted. This meta-analysis provides additional data and insight into the effects of SGLT2 inhibition on reverse cardiac remodelling in patients with HF. Compared with placebo control, we found that treatment with a SGLT2 inhibitor produced significant improvements in several markers of reverse cardiac remodelling.

Tipifarnib Reduces Extracellular Vesicles and Protects From Heart Failure.

Heart failure (HF) is one of the leading causes of mortality worldwide. Extracellular vesicles, including small extracellular vesicles or exosomes, and their molecular cargo are known to modulate cell-to-cell communication during multiple cardiac diseases. However, the role of systemic extracellular vesicle biogenesis inhibition in HF models is not well documented and remains unclear. We investigated the role of circulating exosomes during cardiac dysfunction and remodeling in a mouse transverse aortic constriction (TAC) model of HF. Importantly, we investigate the efficacy of tipifarnib, a recently identified exosome biogenesis inhibitor that targets the critical proteins (Rab27a [Ras associated binding protein 27a], nSMase2 [neutral sphingomyelinase 2], and Alix [ALG-2-interacting protein X]) involved in exosome biogenesis for this mouse model of HF. In this study, 10-week-old male mice underwent TAC surgery were randomly assigned to groups with and without tipifarnib treatment (10 mg/kg 3 times/wk) and monitored for 8 weeks, and a comprehensive assessment was conducted through performed echocardiographic, histological, and biochemical studies. TAC significantly elevated circulating plasma exosomes and markedly increased cardiac left ventricular dysfunction, cardiac hypertrophy, and fibrosis. Furthermore, injection of plasma exosomes from TAC mice induced left ventricular dysfunction and cardiomyocyte hypertrophy in uninjured mice without TAC. On the contrary, treatment of tipifarnib in TAC mice reduced circulating exosomes to baseline and remarkably improved left ventricular functions, hypertrophy, and fibrosis. Tipifarnib treatment also drastically altered the miRNA profile of circulating post-TAC exosomes, including miR 331-5p, which was highly downregulated both in TAC circulating exosomes and in TAC cardiac tissue. Mechanistically, miR 331-5p is crucial for inhibiting the fibroblast-to-myofibroblast transition by targeting HOXC8, a critical regulator of fibrosis. Tipifarnib treatment in TAC mice upregulated the expression of miR 331-5p that acts as a potent repressor for one of the fibrotic mechanisms mediated by HOXC8. Our study underscores the pathological role of exosomes in HF and fibrosis in response to pressure overload. Tipifarnib-mediated inhibition of exosome biogenesis and cargo sorting may serve as a viable strategy to prevent progressive cardiac remodeling in HF.

ROLE OF STATINS ON CARDIAC REMODELING IN HEART FAILURE: A SYSTEMATIC REVIEW

Heart Failure is a chronic condition in which the heart doesnt pump blood as well as it should it is a major cause of morbidity and mortalityglobally.Heart failure is the pathophysiologic state in which the heart, via an abnormality of cardiac function (detectable or not), fails to pump blood at a rate commensurate with the requirements of the metabolizing tissues or is able to do so only with an elevated diastolic filling pressure. As recent studies describe Statins to have a beneficial role in preventing Cardiac remodeling in Heart Failure, this systematic review aims to explore the use of Statins as a potential therapy in patients with Heart Failure. This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)2020 guidelines. The search was conducted using PubMed, PubMed Central, Google Scholar in July 2023. The inclusion criteria were set to free full-text articles published within 5 years, human studies, literature reviews, systematic reviews, meta -analyses, observational studies, RCTs, studies investigating adult samples, and the English language. Exclusion criteria included animal studies, posters, editorials. The primary search yielded18,166 studies, which were screened and subsequently assessed through quality appraisal tools respective to each study. The result of this review demonstrated that statins prevent cardiac remodeling in heart failure. In the end, both randomized and nonrandomized clinical trails are necessary for more conclusive findings.

Fibroblast-localized lncRNA CFIRL promotes cardiac fibrosis and dysfunction in dilated cardiomyopathy.

CFIRL is a long noncoding RNA (lncRNA), we previously identified as the most significantly upregulated lncRNA in the failing hearts of patients with dilated cardiomyopathy (DCM). In this study, we determined the function of CFIRL and its role in DCM. Real-time polymerase chain reaction and in situ hybridization assays revealed that CFIRL was primarily localized in the nucleus of cardiac fibroblasts and robustly increased in failing hearts. Global knockdown or fibroblast-specific knockout of CFIRL attenuated transverse aortic constriction (TAC)-induced cardiac dysfunction and fibrosis in vivo. Overexpression of CFIRL in vitro promoted fibroblast proliferation and aggravated angiotensin II-induced differentiation to myofibroblasts. CFIRL knockdown attenuated these effects. Mechanistically, RNA pull-down assay and gene expression profiling revealed that CFIRL recruited ENO1, a newly identified noncanonical transcriptional factor, to activate IL-6 transcription. IL-6 exerted a paracrine effect on cardiomyocytes to promote cardiac hypertrophy, which can be prevented by CFIRL knockdown. These findings uncover the critical role of CFIRL, a fibroblast-associated lncRNA, in heart failure by facilitating crosstalk between fibroblasts and cardiomyocytes. CFIRL knockdown might be a potent strategy to prevent cardiac remodeling in heart failure, particularly in DCM.

Neutrophils are indispensable for adverse cardiac remodeling in heart failure

Persistent immune activation contributes significantly to left ventricular (LV) dysfunction and adverse remodeling in heart failure (HF). In contrast to their well-known essential role in acute myocardial infarction (MI) as first responders that clear dead cells and facilitate subsequent reparative macrophage polarization, the role of neutrophils in the pathobiology of chronic ischemic HF is poorly defined. To determine the importance of neutrophils in the progression of ischemic cardiomyopathy, we measured their production, levels, and activation in a mouse model of chronic HF 8 weeks after permanent coronary artery ligation and large MI. In HF mice, neutrophils were more abundant both locally in failing myocardium (more in the border zone) and systemically in the blood, spleen, and bone marrow, together with increased BM granulopoiesis. There were heightened stimuli for neutrophil recruitment and trafficking in HF, with increased myocardial expression of the neutrophil chemoattract chemokines CXCL1 and CXCL5, and increased neutrophil chemotactic factors in the circulation. HF neutrophil NETotic activity was increased in vitro with coordinate increases in circulating neutrophil extracellular traps (NETs) in vivo. Neutrophil depletion with either antibody-based or genetic approaches abrogated the progression of LV remodeling and fibrosis at both intermediate and late stages of HF. Moreover, analogous to murine HF, the plasma milieu in human acute decompensated HF strongly promoted neutrophil trafficking. Collectively, these results support a key tissue-injurious role for neutrophils and their associated cytotoxic products in ischemic cardiomyopathy and suggest that neutrophils are potential targets for therapeutic immunomodulation in this disease.

The effect of sodium-glucose cotransporter 2 inhibitors on left cardiac remodelling in heart failure with reduced ejection fraction: Systematic review and meta-analysis.

The therapeutic mechanism of sodium-glucose cotransporter 2 inhibitors (SGLT2i) on left cardiac remodelling in patients with heart failure with reduced ejection fraction (HFrEF) is not well-established. This study meta-analysed the impact of SGLT2i on left cardiac structure and function in patients with HFrEF. Online databases were queried up to April 2023 for trials reporting indicators of left cardiac structure and function in patients with HFrEF treated with SGLT2i. Data from studies were pooled using a random-effects model to derive weighted mean differences (WMDs) and 95% confidence intervals (CIs). Six trials were included (n = 555). Compared with control, SGLT2i significantly improved left ventricular end-diastolic volume (LVEDV; WMD: -17.07 ml [-23.84, -10.31]; p < 0.001), LVEDV index (WMD: -5.62 ml/m2 [-10.28, -0.97]; p = 0.02), left ventricular end-systolic volume (LVESV; WMD: -15.63 ml [-26.15, -5.12]; p = 0.004), LVESV index (WMD: -6.90 ml/m2 [-10.68, -3.11]; p = 0.001), left ventricular ejection fraction (WMD: 2.71% [0.70, 4.72]; p = 0.008), and left atrial volume index (WMD: -2.19 ml/m2 [-4.26, -0.11]; p = 0.04) in patients with HFrEF. SGLT2i use was associated with a non-significant trend towards a reduction in left ventricular mass index (WMD: -6.25 g/m2 [-12.79, 0.28]; p = 0.06). No significant impact on left ventricular global longitudinal strain was noted (WMD: 0.21% [-0.25, 0.67]; p = 0.38). Sodium-glucose cotransporter 2 inhibitors improve cardiac structure and function in patients with HFrEF.

Abstract 13395: Dapagliflozin Reduces Myocardial Sodium Content and Correlates With Reverse Cardiac Remodeling in Nondiabetic Patients With Heart Failure and Preserved Ejection Fraction (Dapa-Sodium)

Introduction: Myocardial sodium overload is a major determinant of adverse cardiac remodeling in heart failure (HF). Sodium tissue content by 23Na magnetic resonance imaging (23Na-MRI) has been validated in human studies. SGLT-2 inhibition blocks sodium reabsorption in renal proximal tubular cells with remarkable cardiovascular outcomes in HF due to mechanisms not yet fully understood. Hypothesis: SGLT-2 inhibition will decrease myocardial sodium content and it will correlate with reverse remodeling in HFpEF. Aim: To determine whether Dapagliflozin leads to decreased myocardial sodium content and reverses pathological hypertrophy in HFpEF. Methods: Prospective, single-center, open-label study of sixty nondiabetic outpatients with HFpEF underwent baseline 23Na-MRI and initiated with dapagliflozin 10 mg once daily according to GDMT. Absolute changes in myocardium relative sodium signal intensity (rSSI) and left ventricular mass index (LVMi) were analyzed from baseline and at 3-month follow-up with 23Na-MRI. Results: All patients exhibited significantly high baseline myocardium rSSI [0.32 (0.28, 0.34)]; 66% above median [0.24 (0.20, 0.27), P = 0.004], decreasing -30% to [0.27 (0.22, 0.30), P&lt;0.001] at 3 months with Dapagliflozin therapy. These changes were correlated with a significant reduction in LVMi of -13 g/m 2 [from 84 g/m 2 (72, 120) to 71 g/m 2 (63, 95), P&lt;0.001]. Conclusions: Dapagliflozin reduces myocardial sodium content and reverses pathological hypertrophy in patients with HFpEF. These findings suggest that SGLT-2 inhibition acts directly on cardiomyocytes and explains the cardioprotective effects demonstrated though large randomized trials.

Abstract 15096: miR-132 Inhibition Shows Anti-Hypertrophic Effects in Preclinical Heart Failure Models and in Exploratory Pharmacodynamic Parameters of a First-in-Human Phase 1b Clinical Trial

Introduction: Cardiac expression levels of miR-132 are elevated in patients with heart failure (HF) and have been associated and provoke pathological cardiac hypertrophy. To inhibit these cardiac remodeling processes and restore normal cardiac function, we developed the synthetic antisense oligonucleotide inhibitor CDR132L targeting miR-132. Anti-hypertrophic effects of miR-132 inhibition have been shown previously in cell culture models and a mouse model of pressure overload-induced HF. Methods and Results: MiR-132 inhibition with CDR132L was now tested in a mouse model of pressure overload induced HF induced by transverse aortic constriction (TAC) and in three different porcine HF models to further confirm the translatability of therapeutic effects. The first pig model was an early post-myocardial infarction (MI). Pigs were treated with CDR132L by intravenous (IV) or intracoronary (IC) infusion on day 3 and day 28 and analyzed on day 56 post-MI. As a second model, chronic post-MI HF pigs received monthly IV treatments over 3 or 5 months starting from month 1 post-MI. Third, percutaneous aortic constriction was induced in pigs by reduction stent implantation and CDR132L was administered IC on day 0 and day 28 followed by analysis on day 56. Hypertrophy was determined by cell size measurements in wheat germ agglutinin (WGA) stained cardiac sections and was significantly decreased between 15% and 29% in CDR132L-treated groups with sufficient dose levels compared to placebo-treatment independent from the large animal model and dosing regimen. Furthermore, TAC mice treated with CDR132L showed a significant decrease in left ventricular mass by 14 % compared to placebo. In line with these data, the cardiac remodeling marker lipocalin-2 (NGAL) was reduced in plasma of chronic HF patients assessed in a first-in-human phase 1b clinical to test safety, efficacy, and also exploratory pharmacodynamics of CDR132L (NCT04045405). Conclusions: Our results confirm beneficial effects of CDR132L treatment on pathological cardiac remodeling in HF.

Cardiac Autoantibodies Against Cardiac Troponin I in Post-Myocardial Infarction Heart Failure: Evaluation in a Novel Murine Model and Applications in Therapeutics.

Cardiac autoantibodies (cAAbs) are involved in the progression of adverse cardiac remodeling in heart failure (HF). However, our understanding of cAAbs in HF is limited owing to the absence of relevant animal models. Herein, we aimed to establish and characterize a murine model of cAAb-positive HF after myocardial infarction (MI), thereby facilitating the development of therapeutics targeting cAAbs in post-MI HF. MI was induced in BALB/c mice. Plasma cAAbs were evaluated using modified Western blot-based methods. Prognosis, cardiac function, inflammation, and fibrosis were compared between cAAb-positive and cAAb-negative MI mice. Rapamycin was used to inhibit cAAb production. Common cAAbs in BALB/c MI mice targeted cTnI (cardiac troponin I). Herein, 71% (24/34) and 44% (12/27) of the male and female MI mice, respectively, were positive for cAAbs against cTnI (cTnIAAb). Germinal centers were formed in the spleens and mediastinal lymph nodes of cTnIAAb-positive MI mice. cTnIAAb-positive MI mice showed progressive cardiac remodeling with a worse prognosis (P=0.014, by log-rank test), which was accompanied by cardiac inflammation, compared with that in cTnIAAb-negative MI mice. Rapamycin treatment during the first 7 days after MI suppressed cTnIAAb production (cTnIAAb positivity, 59% [29/49] and 7% [2/28] in MI mice treated with vehicle and rapamycin, respectively; P<0.001, by Pearson χ2 test), consequently improving the survival and ameliorating cardiac inflammation, cardiac remodeling, and HF in MI mice. The present post-MI HF model may accelerate our understanding of cTnIAAb and support the development of therapeutics against cTnIAAbs in post-MI HF.

Effect of Angiotensin Receptor-Neprilysin Inhibitor on Cardiac Remodeling in Heart Failure with Reduced Ejection Fraction in Kuwait

Abstract Background: Heart failure with reduced ejection fraction (HFrEF) is a growing concern in the Middle East and worldwide, despite advances in treatment. The introduction of angiotensin receptor-neprilysin inhibitor (ARNI) has shown promise in managing HFrEF by inhibiting the renin–angiotensin–aldosterone system. However, its effects on cardiac remodeling and outcomes in the Middle East are poorly understood. Objectives: To determine the effectiveness and safety of ARNI in improving outcomes for HFrEF patients in Kuwait. Methods: This observational study, conducted at Al Dabbous Cardiac Center in Kuwait, included 114 adult HFrEF patients treated with ARNI for 6 months. Data on patient characteristics, echocardiographic measurements, and clinical parameters were collected before and after treatment. Statistical analysis was performed using paired t-tests and nonparametric sign tests. Results: Following ARNI treatment, significant improvements were observed in left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), right ventricular systolic pressure (RVSP), and New York Heart Association Functional Classification. LVEF increased from 29.54% to 32.22% (P &lt; 0.001). LVEDD and RVSP decreased significantly (P &lt; 0.001, P = 0.016, respectively), while systolic blood pressure decreased (P = 0.002). The study showed no significant changes in weight or potassium levels. Adverse effects were minimal. Conclusions: This study contributes to the growing body of evidence supporting ARNI’s effectiveness in improving outcomes for HFrEF patients, particularly in a Middle Eastern population. ARNI treatment resulted in significant improvements in cardiac remodeling and clinical parameters, emphasizing its potential as a valuable therapeutic option for HFrEF patients. Additional research is essential to optimize ARNI’s use and enhance patient outcomes.

Dectin-1 Acts as a Non-Classical Receptor of Ang II to Induce Cardiac Remodeling.

Cardiac remodeling in heart failure involves macrophage-mediated immune responses. Recent studies have shown that a PRR (pattern recognition receptor) called dectin-1, expressed on macrophages, mediates proinflammatory responses. Whether dectin-1 plays a role in pathological cardiac remodeling is unknown. Here, we identified a potential role of dectin-1 in this disease. To model aberrant cardiac remodeling, we utilized mouse models of chronic Ang II (angiotensin II) infusion. In this model, we assessed the potential role of dectin-1 through using D1KO (dectin-1 knockout) mice and bone marrow transplantation chimeric mice. We then used cellular and molecular assays to discover the underlying mechanisms of dectin-1 function. We found that macrophage dectin-1 is elevated in mouse heart tissues following chronic Ang II administration. D1KO mice were significantly protected against Ang II-induced cardiac dysfunction, hypertrophy, fibrosis, inflammatory responses, and macrophage infiltration. Further bone marrow transplantation studies showed that dectin-1 deficiency in bone marrow-derived cells prevented Ang II-induced cardiac inflammation and dysfunction. Through detailed molecular studies, we show that Ang II binds directly to dectin-1, causing dectin-1 homodimerization and activating the downstream Syk (spleen tyrosine kinase)/NF-κB (nuclear factor kappa B) signaling pathway to induce expression of inflammatory and chemoattractant factors. Mutagenesis studies identified R184 in the C-type lectin domain to interact with Ang II. Blocking dectin-1 in macrophages suppresses Ang II-induced inflammatory mediators and subsequent intercellular cross talk with cardiomyocytes and fibroblasts. Our study has discovered dectin-1 as a new nonclassical receptor of Ang II and a key player in cardiac remolding and dysfunction. These studies suggest that dectin-1 may be a new target for treating hypertension-related heart failure.

Vericiguat reduces electrical and structural remodeling in a rabbit model of atrial fibrillation.

Purpose: The molecular etiology of atrial fibrillation (AF) and its treatment are poorly understood. AF involves both electrical and structural features. Vericiguat can ameliorate cardiac remodeling in heart failure. The effects of vericiguat on AF, however, are unclear. Here, the actions of vericiguat on atrial structural and electrical remodeling in AF and its possible mechanisms were investigated. Methods and Results: Thirty-six rabbits were randomly allocated to four groups, namely, sham, RAP (pacing with 600 beats/min over three weeks), vericiguat-treated (three weeks' pacing plus daily oral dose of 1.5 mg/kg of vericiguat), and vericiguat-treated only. HL-1 cells received rapid pacing with or without vericiguat. Parameters including electrophysiology, echocardiography, histology, Ca2+ levels, and ICaL density, as well as levels of TRPC6, CaN, NFAT4, p-NFAT4, Cav1.2, collagen I, collagen III, and ST2 were measured. Significant changes of above proteins expression level, circulating biochemical indices, Ca2+ concentrations, and ICaL density in both animals and cell models, these effects were significantly restored by vericiguat. Vericiguat also reversed the enlarged atrium and significantly reduced myocardial fibrosis, together with preventing reduced atrial effective refractory periods (AERPs) and AF induction rate. Conclusion: Vericiguat thus ameliorated AF-associated structural and electrical remodeling. These findings suggest the potential of vericiguat for treating AF.

Evaluation of therapeutic strategies targeting BCAA catabolism using a systems pharmacology model.

Background: Abnormal branched-chained amino acids (BCAA) accumulation in cardiomyocytes is associated with cardiac remodeling in heart failure. Administration of branched-chain α-keto acid dehydrogenase (BCKD) kinase inhibitor BT2 has been shown to reduce cardiac BCAA levels and demonstrated positive effects on cardiac function in a preclinical setting. The current study is focused on evaluating the impact of BT2 on the systemic and cardiac levels of BCAA and their metabolites as well as activities of BCAA catabolic enzymes using a quantitative systems pharmacology model. Methods: The model is composed of an ordinary differential equation system characterizing BCAA consumption with food, disposal in the proteins, reversible branched-chain-amino-acid aminotransferase (BCAT)-mediated transamination to branched-chain keto-acids (BCKA), followed by BCKD-mediated oxidation. Activity of BCKD is regulated by the balance of BCKDK and protein phosphatase 2Cm (PP2Cm) activities, affected by BT2 treatment. Cardiac BCAA levels are assumed to directly affect left ventricular ejection fraction (LVEF). Biochemical characteristics of the enzymes are taken from the public domains, while plasma and cardiac BCAA and BCKA levels in BT2 treated mice are used to inform the model parameters. Results: The model provides adequate reproduction of the experimental data and predicts synchronous BCAA responses in the systemic and cardiac space, dictated by rapid BCAA equilibration between the tissues. The model-based simulations indicate maximum possible effect of BT2 treatment on BCAA reduction to be 40% corresponding to 12% increase in LVEF. Model sensitivity analysis demonstrates strong impact of BCKDK and PP2Cm activities as well as total BCKD and co-substrate levels (glutamate, ketoglutarate and ATP) on BCAA and BCKA levels. Conclusion: Model based simulations confirms using of plasma measurements as a marker of cardiac BCAA changes under BCKDK inhibition. The proposed model can be used for optimization of preclinical study design for novel compounds targeting BCAA catabolism.

Role of m6A Methylation in the Occurrence and Development of Heart Failure.

N6-methyladenosine (m6A) RNA methylation is one of the most common epigenetic modifications in RNA nucleotides. It is known that m6A methylation is involved in regulation, including gene expression, homeostasis, mRNA stability and other biological processes, affecting metabolism and a variety of biochemical regulation processes, and affecting the occurrence and development of a variety of diseases. Cardiovascular disease has high morbidity, disability rate and mortality in the world, of which heart failure is the final stage. Deeper understanding of the potential molecular mechanism of heart failure and exploring more effective treatment strategies will bring good news to the sick population. At present, m6A methylation is the latest research direction, which reveals some potential links between epigenetics and pathogenesis of heart failure. And m6A methylation will bring new directions and ideas for the prevention, diagnosis and treatment of heart failure. The purpose of this paper is to review the physiological and pathological mechanisms of m6A methylation that may be involved in cardiac remodeling in heart failure, so as to explain the possible role of m6A methylation in the occurrence and development of heart failure. And we hope to help m6A methylation obtain more in-depth research in the occurrence and development of heart failure.

Cardiac Remodeling in Heart Failure: Role of Pyroptosis and Its Therapeutic Implications.

Pyroptosis is a kind of programmed cell death closely related to inflammation. The pathways that mediate pyroptosis can be divided into the Caspase-1-dependent canonical pathway and the Caspase4/5/11-dependent non-canonical pathway. The most significant difference from other cell death is that pyroptosis rapidly causes rupture of the plasma membrane, cell expansion, dissolution and rupture of the cell membrane, the release of cell contents and a large number of inflammatory factors, and send pro-inflammatory signals to adjacent cells, recruit inflammatory cells and induce inflammatory responses. Cardiac remodeling is the basic mechanism of heart failure (HF) and the core of pathophysiological research on the underlying mechanism. A large number of studies have shown that pyroptosis can cause cardiac fibrosis, cardiac hypertrophy, cardiomyocytes death, myocardial dysfunction, excessive inflammation, and cardiac remodeling. Therefore, targeting pyroptosis has a good prospect in improving cardiac remodeling in HF. In this review, the basic molecular mechanism of pyroptosis is summarized, the relationship between pyroptosis and cardiac remodeling in HF is analyzed in-depth, and the potential therapy of targeting pyroptosis to improve adverse cardiac remodeling in HF is discussed, providing some ideas for improving the study of adverse cardiac remodeling in HF.

Reduction of extracellular volume and reverse cardiac remodeling during sacubitril/valsartan therapy assessed by cardiac magnetic resonance in patients with heart failure (REMODELING CMR-HF)

Abstract Funding Acknowledgements Type of funding sources: None. OnBehalf REMODELING HF Background/Introduction: Extracellular volume (ECV) expansion is a major determinant of cardiac remodeling in heart failure. Cardiac magnetic resonance (CMR) T1 mapping has been developed as a noninvasive technique to estimate ECV. Purpose The objective of this study is to assess the response to Sacubitril/Valsartan by measuring changes in myocardial ECV and their association with reverse cardiac remodeling in patients with heart failure with reduced ejection fraction (HFrEF). Methods Prospective, single-center, open-label study of two hundred-four HFrEF patients underwent CMR T1 mapping using the modified Look-Locker inversion recovery (MOLLI) sequence for ECV calculation, and initiated with sacubitril-valsartan treatment according to Guideline-Directed Medical Therapy. Absolute change in myocardial ECV, serum levels of procollagen type I amino-terminal peptide (PINP) and procollagen type III amino-terminal peptide (PIIINP), left ventricular end-diastolic volume index, left ventricular end-systolic volume index and left ventricle ejection fraction (LVEF) were analyzed from baseline to 12-month follow-up. Results Baseline MOLLI-ECV was 48.2% ± 2.4 in 106 patients with ischemic cardiomyopathy (ICM) and 38.7% ± 2.7 in 98 with idiopathic dilated cardiomyopathy (DCM), decreasing to 34% ± 2.4 for ICM and 29.5% ± 2.7 for DCM (P &amp;lt; 0.001), at 12 months with sacubitril-valsartan therapy. These changes were correlated with a reduction of -36 μg/L for PINP (CI 95% 78-93, P &amp;lt; 0.001), and -3.0 μg/L for PIIINP (CI 95% 73-91, P &amp;lt; 0.001), -20 ml/m² in left ventricle end-diastolic and -18 ml/m² in end-systolic volumes, and an improvement in LVEF from 29% to 36% in both groups (P &amp;lt; 0.001). Conclusions For the first time, we observe that changes in extracellular volume induced by sacubitril-valsartan therapy are related to reverse cardiac remodeling in patients with in HFrEF. These findings suggest that there may be an opportunity to decrease adverse remodeling with the use of a CMR-guided therapeutic approach aimed at decreasing fibrogenic activity and modulate the remodeling process.

Association Between Angiotensin Receptor-Neprilysin Inhibition, Cardiovascular Biomarkers, and Cardiac Remodeling in Heart Failure With Reduced Ejection Fraction.

Sacubitril/valsartan (S/V) treatment is associated with reverse cardiac remodeling and reductions in biomarkers reflecting ventricular wall stress and myocardial injury, such as NT-proBNP (N-terminal pro-B-type natriuretic peptide), hs-cTnT (high-sensitivity cardiac troponin T), and soluble suppressor of tumorigenicity 2 (sST2). How longitudinal changes in these biomarkers analyzed collectively are associated with cardiac remodeling in patients with heart failure with reduced ejection fraction treated with S/V is uncertain. In a prospective study of S/V in patients with heart failure with reduced ejection fraction, this prespecified exploratory analysis included patients with serially collected biomarkers and echocardiographic measures of cardiac remodeling through 12 months of treatment. A multivariate latent growth curve model assessed associations between simultaneous changes in biomarkers and left ventricular ejection fraction and left atrial volume index. Seven hundred fifteen out of 794 total study participants were included (mean age 65 years, 73% male). Mean baseline left ventricular ejection fraction and left atrial volume index were 29% and 40 mL/m2, respectively. Adjusted geometric mean baseline concentrations for biomarkers included NT-proBNP of 649 pg/mL, hs-cTnT of 15.9 ng/L, and sST2 of 24.7 ng/mL. Following initiation of S/V, circulating concentrations of NT-proBNP, hs-cTnT, and sST2 significantly decreased within 30 days and remained significantly different than baseline at all subsequent timepoints. From baseline to month 12, decreases in adjusted biomarker concentrations averaged -27.9% (95% CI, -35.1% to -20.7%; P<0.001) for NT-proBNP; -6.7% (95% CI, -8.8% to -4.7%; P<0.001) for hs-cTnT; and -1.6% (95% CI, -2.9% to -0.4%; P<0.001) for sST2. NT-proBNP concentrations were predictive of later changes in hs-cTnT. The magnitude of reductions in NT-proBNP and hs-cTnT concentrations associated with improvements in left ventricular ejection fraction and left atrial volume index. There was no association between changes in sST2 and changes in other measures. Following initiation of S/V, NT-proBNP, hs-cTnT, and sST2 concentrations decreased significantly. Longitudinal changes in NT-proBNP and hs-cTnT together associated with left atrial and left ventricular reverse remodeling. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02887183.

ATPase Inhibitory Factor-1 Disrupts Mitochondrial Ca2+ Handling and Promotes Pathological Cardiac Hypertrophy through CaMKIIδ.

ATPase inhibitory factor-1 (IF1) preserves cellular ATP under conditions of respiratory collapse, yet the function of IF1 under normal respiring conditions is unresolved. We tested the hypothesis that IF1 promotes mitochondrial dysfunction and pathological cardiomyocyte hypertrophy in the context of heart failure (HF). Methods and results: Cardiac expression of IF1 was increased in mice and in humans with HF, downstream of neurohumoral signaling pathways and in patterns that resembled the fetal-like gene program. Adenoviral expression of wild-type IF1 in primary cardiomyocytes resulted in pathological hypertrophy and metabolic remodeling as evidenced by enhanced mitochondrial oxidative stress, reduced mitochondrial respiratory capacity, and the augmentation of extramitochondrial glycolysis. Similar perturbations were observed with an IF1 mutant incapable of binding to ATP synthase (E55A mutation), an indication that these effects occurred independent of binding to ATP synthase. Instead, IF1 promoted mitochondrial fragmentation and compromised mitochondrial Ca2+ handling, which resulted in sarcoplasmic reticulum Ca2+ overloading. The effects of IF1 on Ca2+ handling were associated with the cytosolic activation of calcium–calmodulin kinase II (CaMKII) and inhibition of CaMKII or co-expression of catalytically dead CaMKIIδC was sufficient to prevent IF1 induced pathological hypertrophy. Conclusions: IF1 represents a novel member of the fetal-like gene program that contributes to mitochondrial dysfunction and pathological cardiac remodeling in HF. Furthermore, we present evidence for a novel, ATP-synthase-independent, role for IF1 in mitochondrial Ca2+ handling and mitochondrial-to-nuclear crosstalk involving CaMKII.