bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the role of WT1 in Brugada syndrome pathophysiology
Authors: Marsman E M J , Bosada F M , Offerhaus J A , Beekman L , Wilde L M , Casini S , Verkerk A O , Wilde A A M , Boukens B J , Remme C A , Bezzina C R 
Published: October 2024

Abstract

Background
Brugada syndrome (BrS) is a heritable arrhythmic disorder presumably caused by conduction slowing in the right ventricular (RV) outflow tract (RVOT). A recent genome-wide association study found an association between common variants on chromosome 11 near WT1, tagged by the SNP rs72905083, and BrS susceptibility.

Purpose
To study whether WT1 affects cardiac conduction and could therefore represents the underlying association of the chr11 locus with BrS susceptibility.

Methods
We conducted in silico analyses of omics datasets to identify the likely causal gene at the chr11 BrS locus. Next, we conducted electrophysiological studies in heterozygous young adult (4 months old) Wt1-deficient (Wt1+/-) mice and wild-type littermates to explore the effect of Wt1 on cardiac conduction. To study the potential role of Wt1 in the setting of reduced conduction reserve, we compared aged Scn5a haploinsufficient mice (Scn5a+/-;Wt1+/+, 17 months) with littermates haploinsufficient for both Wt1 and Scn5a (Scn5a+/-;Wt1+/-). Optical mapping was performed in Langendorff-perfused hearts, where conduction was further challenged by acute ajmaline administration or by pacing at the effective refractory period (ERP). Transcriptomic analyses were conducted in Wt1+/- and wild-type mice by RNAseq of PCM1-sorted cardiomyocytes.

Results
Analysis of omics datasets uncovered WT1 as the likely causal gene since WT1 was the closest gene to, and in fact overlapped, the BrS-associated region; promoter capture Hi-C data in human tissue showed chromatin contact between the promoter of WT1 and the associated region; and H3K27ac ChIP-seq signals (i.e. enhancer activity) of putative cardiac enhancers located within the associated region were correlated with WT1 transcript abundance across multiple tissues (Z-score = 4.32, p=1.57e-05).
No differences were observed in ECG parameters or optically mapped epicardial conduction between Wt1+/- mice and wild-type littermates. However, comparison of aged Scn5a+/-;Wt1+/- and Scn5a+/-; Wt1+/+ hearts, in the setting of acute ajmaline challenge or pacing at the ERP, showed faster conduction in RV/RVOT in the presence of Wt1 haploinsufficiency (genotype effect: p=0.057 and p=0.041 for RV and RVOT epicardial conduction, respectively, during ajmaline challenge; p=0.034 for RV epicardial conduction during pacing at ERP).
RNAseq of RV/RVOT cardiomyocytes revealed higher Scn5a expression in Wt1+/- vs wild-type (p=0.006).

Conclusion
We identified WT1 as the gene that most likely underlies the effect of the chr11 BrS susceptibility locus. Functional data revealed protective effects of reduced Wt1 expression in the setting of reduced conduction reserve. Transcriptomic data suggest that this occurs through a transcriptional effect on Scn5a expression.
METTL3 drives heart failure by regulating Spp1 and Fos m6A modification in myocardial infarction
Authors: Cheng H , Li L N , Qian J Y , Zou Y Z , Ma J Y , Ge J B 
Published: October 2024

Abstract

Background
While m6A modification has been reported in myocardial infarction (MI), the detailed mechanism by which METTL3 regulates the progression of the disease has not yet been elucidated, and it remains unclear why m6A modification increases after MI.

Purpose
To investigate the role and mechanism of METTL3 in regulating its targets through m6A methylation in MI. The research results will not only add new content to the basic mechanism of myocardial protection but also provide new ideas and new targets for the prevention and treatment of MI.

Methods
Through MeRIP-seq and extensive bioinformatics analysis, the target genes SPP1 and FOS with the most significant m6A modification and differential expression in MI were screened. We successfully constructed heart specific Mettl3 knockout mice (Mettl3CKO) to verify that METTL3 promotes the deterioration of cardiac function after MI. We performed complementary molecular methods to assess protein quantity and interactions to identify mechanisms regulating this response. We manipulated select molecular pathways using both genetic and pharmacological methods to validate these mechanisms.

Results
Here, we showed that METTL3 exerted methyltransferase activity-dependent functions in gene regulation in MI, and a significant transcription factor HuR assisted the function of METTL3. and demonstrated that METTL3 was critical for the promotion of heart failure after MI. More specifically, METTL3 directly interacted with HuR through its nuclear localization domain in the cell nucleus under normoxia condition. When hypoxia developed, METTL3 separated from HuR and deposited m6A into 5’UTR of Spp1 and Fos mRNA to maintain their stability. In contrast, HuR bound to the ARE domain of 3’UTR of Spp1 and Fos mRNA to take them to the cytosol, maintaining their stability. Moreover, HIF-1α directly interacted with the HRE domain of Mettl3 to promote its transcription, and HuR bound to the ARE domain of 3’UTR of Mettl3 mRNA to maintain its stability to promote following translation.

Conclusions
Collectively, our studies revealed previously unappreciated functions of METTL3 with the help of HuR, and a direct target of HIF-1α under normoxia condition, which together contribute to its essential function in MI, suggesting therapeutic potential for targeting the METTL3/HuR/Spp1(Fos) mRNA axis.Figure1
Fractalkine Inhibition in Acute Myocardial Infarction leads to reduced intramyocardial haemorrhage
Authors: Loh S , Ekinci Y , Bennaceur K , Ogundimu E , Bigirumurame T , Maier R , Jeyalan V , Egred M , Mcdiarmid A , Maredia N , Plein S , Olin T , Richardson G , Austin D , Spyridopoulos I 
Published: October 2024

Abstract

Background
The fractalkine receptor CX3CR1 has been linked to the development of microvascular obstruction (MVO) in ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI). Pre-clinical studies have demonstrated a reduction in infarct size, inflammation and intramyocardial haemorrhage (IMH) with inhibition of CX3CR1.

Purpose
The FRACTAL study is a phase IIa, pilot, randomized, 2-arm parallel group, placebo-controlled, double blinded, multi-centre trial. In addition to assessing the safety and tolerability of the fractalkine inhibitor KAND567 in STEMI patients, a subgroup exploratory analysis was performed. We investigated into the translation of MRI and blood samples characteristics between the two groups.

Methods
Patients with an anterior STEMI who had an occluded proximal to mid left anterior descending (LAD) artery were recruited. These patients had to present within 5 hours of the onset of their chest pain. They were subsequently randomised on a 1:1 basis to receive either KAND567 or placebo. Patients then underwent an MRI at day 3, and subsequently a comparator at 3 months. Additionally, throughout the period of their follow-up, patients would regularly undergo blood sampling to assess multiple parameters.

Results
Of the 71 patients recruited into the study, 29 patients in the KAND567 arm and 28 patients in the placebo arm received both MRIs. The KAND567 arm had shown a similar troponin rise at day 1 compared to placebo (4357 vs 4286). Baseline MRI demonstrated an identical infarct size between both arms. The presence and absence of IMH was then analysed defining IMH+ as presence of IMH and IMH- as IMH absence. The presence of IMH in patients showed a larger infarct size. The infarct size of IMH+ were the same between KAND567 and placebo, which was a similar finding in the IMH- arm too. However, when compared to day 90 MRI demonstrated a numerically smaller infarct size in the KAND567 group with a smaller percentage of IMH. This was consistent with a lower rate of IMH in the KAND567 arm too, when compared between the groups (35.5% vs 55.2%; p=0.15) (see table below). This seemed to be related to the smaller distribution IMH+, as the IMH+ infarcts were much larger in both arms, whilst overall infarct size in IMH subgroup were identical.

Conclusion
KAND567 appears to prevent the transition from IMH- to IMH+, while it doesn’t change infarct size in the respective subgroups of IMH+ or IMH-.MRI Comparator Table
Red blood cell distribution width to albumin ratio as novel prognostic biomarker in cardiovascular disease
Authors: Arba I F , Multazam C C Z , Widiarti W , Siahaan P P , Oktaviono Y H , Setyobudi D , Saputra P B T 
Published: October 2024

Abstract

Background
The red blood cell distribution width-to-albumin ratio (RAR) is a novel, cost-effective, and accessible biomarker for inflammation. Although numerous studies have investigated the relationship between RAR values and mortality in cardiovascular diseases (CVD), the generalizability and robustness of these individual studies' results remain uncertain, underscoring the necessity for a meta-analysis.

Purpose
To explore the pooled association between RAR and all-cause mortality in several CVDs.

Methods
A systematic search for eligible studies was conducted across scientific databases, including Scopus, Web of Science, PubMed, and ProQuest, up to February 1, 2024. Mortality hazard ratios (HRs) for the highest versus lowest RAR categories were pooled using the Generic Inverse Variance method. A dose-response meta-analysis was performed using generalized least-squares regression to estimate trends of HRs across dose categories. Publication bias was assessed by inspecting funnel plots and performing Egger's test. Subgroup analyses were based on the underlying CVDs. Statistical analyses were executed in RStudio software, with the significance threshold set at p &lt; 0.05.

Results
This systematic review and meta-analysis reviewed 16 high-quality studies published between 2021 and 2024 with 30,933 participants. The underlying diseases in the included studies were Acute Myocardial Infarction (AMI), Heart Failure (HF), Atrial Fibrillation (AF), aortic valvular disease, stroke and pulmonary embolism. The lowest quartile range for RAR was 0.80–1.20 ml/g, while the highest quartile ranged from 6.09 to 15.45 ml/g. Pooled results with a random-effect model showed that patients with higher RAR had significantly increased risk of all-cause mortality (HR 1.88, 95%CI 1.59–2.23, p&lt;0.0001, I² = 91%). Non-linearity was observed in the dose-response relationship; thus, it was primarily illustrated using the restricted cubic spline model, with the linear model provided for comparison. A 1 ml/g increase in RAR corresponded to a 27% rise in the predicted HR for all-cause mortality (HR 1.27, 95%CI 1.16–1.39; p &lt; 0.0001). Subgroup analyses based on the primary CVD diagnoses in the included studies confirmed a significant association between RAR values and all-cause mortality across all subgroups (AMI: HR 2.43, 95%CI 1.52–3.87, I² = 45%; HF: HR 1.78, 95%CI 1.13–2.81, I² = 94%; Stroke: HR 1.58, 95%CI 0.94–2.67, I² = 90%; Other CVD: HR 1.97, 95%CI 1.34–2.89, I² = 57%; p for interaction 0.24).

Conclusion
This is the first meta-analysis demonstrating the positive dose-response association between RAR values and all-cause mortality in CVD. Thus, RAR may be considered as a simple and practical prognostic biomarker in CVD.Forest plot based on CVD diagnosisDose-response RAR value to HR
LCZ696 (sacubitril/valsartan) alleviates residual cardiac remodeling of large ventricular aneurysms after surgical ventricular reconstruction by mediating circMap4k2/LIN28A/PDK1 pathway
Authors: Yan J , Tan N 
Published: October 2024

Abstract

Introduction
The treatment of refractory heart failure (HF) with large ventricular aneurysms (LVA) faces difficulties and requires effective therapy. Surgical ventricular reconstruction (SVR) is used to reverse cardiac remodeling for these patients, however, residual remodeling and dysfunction after SVR limits the improvement of HF. Recently, we reported that circMap4k2 promoted cardiac regeneration in the plication zone and attenuated residual remodeling after SVR. LCZ696 (sacubitril/valsartan) can reduce cardiac remodeling in early HF, while efficacy is poor in refractory HF with severe remodeling. It is unclear whether LCZ696 could improve residual remodeling and regulate circMap4k2 after SVR attenuates partial cardiac remodeling.

Purpose
We aimed to explore whether LCZ696 would reverse residual remodeling after SVR and related mechanisms.

Methods
Adult Male C57BL/6 mice were subjected to myocardial infarction (MI) or sham surgery. Four weeks later, MI mice with a LVA underwent SVR or a second open-chest operation and were randomized to LCZ696 or vehicle for four-week. Echocardiography and histological analysis were used to evaluate heart function, cardiac remodeling, and myocardial regeneration. Bioinformatics analysis, molecular docking analysis, RNA immunoprecipitation (RIP) and RNA pulldown were used to explore the underlying mechanisms.

Results
Compared with vehicle-treated SVR and LCZ696-treated non-SVR mice, LCZ696-treated SVR mice had significantly smaller left ventricular volume, better ejection fraction, lower heart-to-body weight ratio, less myocardial fibrosis and more positive staining of Ki-67, phospho-histone H3, and Aurora B in the plication zone. LCZ696 up-regulated the cardiac expression of circMap4k2 in SVR mice. Silencing of circMap4k2 markedly blocked the curative effects of LCZ696 on SVR mice, while overexpression of circMap4k2 enhanced these effects. We predicted 22 proteins that may bind to circMap4k2, among which lin-28 homolog A (LIN28A) had the highest binding potential, and confirmed the combination between circMap4k2 and LIN28A. Mechanistically, LCZ696-induced circMap4k2 bound to LIN28A, increased downstream pyruvate dehydrogenase kinase 1 (PDK1) expression, which activated glycolysis in injured myocardium and ultimately promoted cardiomyocyte proliferation.

Conclusions
LCZ696 improves cardiac metabolism and increases cardiac regeneration in the plication zone by mediating circMap4k2/LIN28A/PDK1 pathway, thereby attenuating residual remodeling and restoring heart function after SVR.
RBM20 promotes doxorubicin-induced cardiotoxicity by Atp6v0a1 alternative splicing
Authors: Qiu Z , Sun Z , Wang Z , Wu Y , Li Z , Fan Y , Yang W , Chen Y , Hua S , Jin W 
Published: October 2024

Abstract
Background & Objective: Doxorubicin (dox), an effective chemotherapy drug, is extremely limited in clinical practice by its lethal cardiotoxicity. Whereas dysregulation of splice-regulatory networks has been reported in cardiomyopathies, the role of RNA binding motif protein 20 (RBM20), an adaptive splice regulator, in doxorubicin-induced cardiotoxicity (DIC) remained to be elucidated.

Purpose
Here we aimed to show the role of RBM20 in DIC and elucidate the relationship between alternative splicing and lysosome acidification impairment.

Method
Mice were treated with intraperitoneal injection of cumulative 20mg/kg doxorubicin with four equal injections over a period of 2 weeks to induce DIC. The contribution of RBM20 in cardiotoxicity was evaluated in conditional cardiomyocyte-specific RBM20 overexpression (RBM20tg/+/Myh6-CreERT) mice. The regulatory factor of RBM20 was determined through luciferase assay and chromatin immunoprecipitation in vitro. Autophagic flux was evaluated by transmission electron microscope in RBM20tg/+/Myh6-CreERT mice and by lysotracker and a tandem fluorescence RFP-GFP-LC3 reporter system in RBM20 overexpressed or knockdown cardiomyocyte. RBM20-dependent splicing events were identified by rMATS 3.2.5 on the RNA-sequencing data.

Results
In the DIC human myocardium and murine model, we observed significant elevation of RBM20 in cardiomyocytes. Cardiomyocyte-specific RBM20 overexpression resulted in severe cardiac dysfunction reflected by dilated ventricles, declined left ventricular ejection fraction, increased chamber stiffness and lower survival rate. After screening for potential upstream transcription factors, c-Jun was identified to bind and upregulate RBM20 directly. The inhibition of c-Jun by SR 11302 could partially mitigate DIC in vitro. Mechanistically, RBM20 was positively related with autophagic flux blockade and impaired lysosome acidification by shifting Atp6v0a1, the a1-subunit of the V0 domain of vacuolar H+-ATPases, toward an exon 6-7 exclusion isoform without altering total transcript levels. By restoring exon 6-7-containing ATP6V0a1 level, we were able to reduce DIC by restoring normal autophagic flux.

Conclusion
Overall, our study reveals that elevation of RBM20 disturbed lysosome acidification in doxorubicin induced cardiotoxicity via the alternative splicing of Atp6v0a1, leading to heart failure.JUN-Rbm20 upregulattion promoted DICRBM20 alternative spliced atp6v0a1
The contribution of iron metabolism to heart failure: a haematological and biochemical perspective
Authors: Menezes Falcao L , Matias A , Santos M , Aguiar L , Barbosa M , Melicio A , Faustino P , Bicho M , Inacio A 
Published: October 2024

Abstract

Introduction
Heart failure (HF) can be influenced by diverse modulators, such as genes involved in iron metabolism - HFE, SLC40A1 and TMPRSS6, and haematological and biochemical parameters - serum iron, ferritin, transferrin saturation, mean corpuscular volume (MCV) and Red Cell Distribution Width (RDW).

Objectives
To investigate the association of genetic variants in the HFE gene [C282Y (rs1800562) and H63D (rs1799945)], SLC40A1 (rs1439816 and rs2304704) and TMPRSS6 (rs855791) with haematological parameters and biochemical biomarkers of iron metabolism in HF and in its various forms of presentation [preserved Ejection Fraction-HFpEF and non-preserved Ejection Fraction-HFnpEF (middly reduced + reduced)], in each sex.

Methods
301 individuals with HF were studied (141 men and 160 women), with a median age of 80 years (min=31 and max=99) and a median body mass index (BMI) of 25.90 kg/m2 (min=16.50 and max=47.30). Multiplex PCR-ARMS technique was used to analyze the HFE gene variants (C282Y and H63D) and Endpoint Genotyping was used for the remaining variants. Statistical analysis was carried out using SPSS software, version 28.0, with a statistical significance level of p&lt;0.05.

Results
The presence of indicators of iron deficiency anaemia was verified in the haematological and biochemical parameters in our population of HF. Significant differences were found in serum iron values in the presence of the mutant allele for the three genes studied: 1)in the H63D (p=0.006) for females, and more particularly in females with HFnpEF (p=0.020); 2) in the rs1439816 for males (p=0.035) and more particularly in males with HFpEF (p=0.036); and 3) in the rs855791 for males (p=0.018). As for ferritin, significant differences were found in the presence of the mutant allele for the rs2304704 (p=0.001) in females. For transferrin saturation, significant differences were found in the presence of the mutant allele for the three genes studied: 1) in the H63D (p=0.013) for females, more specifically in females with HFpEF (p=0.043); 2) in the rs1439816 in males (p=0.037); and 3) in the rs855791 in females (p=0.034), particularly in females with HFpEF (p=0.023), and in males (p=0.032), particularly in males with HFpEF (p=0.037). Analyzing the MCV, there were statistically significant differences in the presence of the mutant allele for the rs2304704 (p=0.012) in females, particularly in those with HFpEF (p&lt;0.001). Regarding RDW, significant differences were found in the presence of the mutant allele of the C282Y polymorphism in females with HFpEF (p=0.048).

Conclusion
Ferropenic anaemia highly prevalent in this population with HF. All the genes analyzed contribute to the modulation of the analyzed parameters/biomarkers, however, the SLC40A1 gene showed greater modulating capacity. Genetic modulation was more relevant in HFpEF women, suggesting that this sex is the most susceptible to genetic modulation.
Stress memory of heart failure in hematopoietic niche promotes recurrence via adipocytic skewing of mesenchymal stromal cells
Authors: Goto K , Nakayama Y , Manabe I , Komuro I , Fujiu K , Takeda N 
Published: October 2024

Abstract

Background
Heart failure (HF) is marked by recurrent acute decompensations, which poses significant treatment challenges in advanced stages. Our preceding work demonstrated that hematopoietic stem cells (HSCs) from HF-experienced mice induce cardiac fibrosis and dysfunction when transplanted, as a result of epigenetic alterations favoring myeloid hematopoiesis and impeding the differentiation of monocytes into cardiac mature macrophages. These findings hint at epigenetic modifications in HSCs as potential drivers of HF recurrence, suggesting their manipulation as a novel therapeutic strategy. However, the exact mechanisms by which HF-associated stress leads to these epigenetic changes remain unclear. Given the crucial role of bone marrow mesenchymal stromal cells (MSCs) in maintaining HSC stemness, this study explores the impact of cardiac stress on MSC function and its subsequent effect on HSCs.

Purpose
This study aims to elucidate the mechanisms behind the phenotypic changes in HSCs and to identify novel therapeutic targets to mitigate HF recurrence by investigating the role of MSCs in the hematopoietic niche under cardiac stress.

Methods & Results
Initially, we examined MSC phenotypic changes during HF using bulk and single-cell RNA sequencing. Results from transverse aortic constriction (TAC) model mice revealed a shift towards adipocyte differentiation under cardiac stress. Histological analyses confirmed an increase in adipocytes in TAC mice compared to controls, suggesting a stress-induced predisposition of MSCs towards adipocytic lineage commitment. This trend was further supported by ex vivo models using MSCs isolated from TAC mice. Notably, the proportion of adipocyte lineage-specific MSCs correlated with cardiac dysfunction severity.
Subsequently, we assessed the impact of HF-conditioned MSCs on HF development by transplanting healthy HSCs with MSCs from control or TAC mice. Mice receiving HF-conditioned MSCs developed HF, evidenced by reduced ejection fraction and cardiac fibrosis. In these mice, a notable increase in HSC proliferation and a relative increase of myeloid cells within the peripheral blood were observed, along with an increase in proinflammatory cardiac macrophages. These findings suggest HF induces a "stress memory" in bone marrow MSCs.
To test the potential of inhibiting adipocyte differentiation of MSCs in erasing this stress memory, we administered MSC phenotype-modulating agents to TAC mice, resulting in improved cardiac function and the disappearance of adipocytes from the bone marrow.

Conclusions
This study sheds light on how cardiac stress affects the bone marrow niche, leading to adipocytic skewing of MSCs and subsequent alterations in HSCs, thereby exacerbating cardiac dysfunction. The potential of targeting bone marrow niche components in HF treatment is highlighted.