bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discrimination and calibration are insensitive metrics for comparing the performance of cardiovascular risk prediction models
Authors: Liang J , Jackson R , Wells S , Poppe K 
Published: October 2024

Abstract

Background/Introduction
Accurate cardiovascular disease (CVD) risk prediction models can facilitate the identification and cost-effective treatment of high-risk individuals. Discrimination and calibration are the most commonly recommended metrics for evaluating model performance. However, both are population-level measures, and it remains unclear whether these metrics are sufficiently sensitive to assess the performance of models designed for use with individual patients.

Purpose
Using a real-world dataset, we aimed to compare CVD risk estimates for example individuals (individual-level measures) and discrimination and calibration metrics (population-level measures) from two CVD risk prediction models; one with "age" as the only predictor and one with multiple predictors.

Methods
We constructed a cohort of almost all New Zealanders without CVD or heart failure, alive and aged 30–79 years in 2014, with follow-up linkage to hospitalisations and mortality until 2018 (N = 2,098,359). We derived two sets of sex-specific Cox regression models to predict 5-year CVD risk. The age-only models included "age" as the only predictor, and the full models used nine pre-defined routinely available CVD risk predictors with interaction terms. We calculated and compared individuals’ 5-year CVD risk from the age-only and full models and assessed model performance using Harrell’s C-statistics and calibration plots.

Results
Risk estimates for individuals using the two models showed substantial differences. A 65-year-old woman had predicted 5-year risks of 4.9% with the age-only model but 16.1% with the full model; a 74-year-old man had predicted risks of 15.2% and 9.2%, respectively, with age-only and full models (Figure 1). However, the models had similar discrimination and calibration (Figure 2). Age-only models had good discrimination with C-statistics of 0.773 (95% CI: 0.771–0.775) in women and 0.740 (0.738–0.742) in men, and calibrated well in both sexes. The full models had slightly better discrimination (C-statistics: 0.814 [0.812–0.816] in women and 0.769 [0.767–0.771] in men), and very similar calibration to the age-only models in both sexes.

Conclusions
Age-only models showed good discrimination and were well calibrated, but predicted very different risks in individual case studies compared to models with multiple predictors. This study calls into question the use of discrimination and calibration metrics as the main measures for comparing the performance of different CVD risk prediction models. We recommend that examples of predicted risk for individuals and an assessment of the magnitude and prevalence of cardiovascular predictors should also be considered when comparing the performance of prognostic models.
Identification of cell adhesion molecules for the maturation of engineered heart tissue
Authors: Fujiwara Y , Naka Y , Sasalo M , Imahashi K , Yoshida Y 
Published: October 2024

Abstract

Background
Engineered cardiac tissue (ECT) utilizing human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) is anticipated to function as a translational in vitro model. However, hiPSC-CMs display phenotypes indicative of immaturity, and the structural organization of ECT composed of hiPSC-CMs is insuficient when compared to that of mature adult hearts. Although the mechanisms for hiPSC-CMs maturation have been reported, little is known about the mechanisms regulating the formation of in vitro tissue such as ECT. Cell adhesion molecules play important roles in heart formation in vivo through cell-cell interactions. However, specific cell adhesion molecules responsible for tissue structure formation in in vitro tissue models, such as ECTs, have not been identified. We hypothesize that cell adhesion molecules, which regulate cell-cell attachment, are crucial for in vitro tissue formation.

Purpose
This study aims to identify the key cell adhesion molecules involved in cell-cell interaction and assess the effects of their expression on hiPSC-CMs and EHT functions.

Methods and Results
We developed a cell attachment assay to evaluate the attachment ability of hiPCS-CMs and discovered that hiPSC-CMs produced via embryoid body method (EB-hiPSC-CMs) exhibited a higher attachment ability than those produced by monolayer method (Mono-hiPSC-CMs). Further analysis revealed no significant difference in anoikis sensitivity between EB-hiPSC-CMs and Mono-hiPSC-CMs, suggesting that the observed difference in attachment ability were due to differencies in cell adhesion efficiency between hiPSC-CMs generated by two methods. Moreover, RNA-seq analysis identified nine cell adhesion molecule genes that were highly expressed in EB-hiPSC-CMs. We identified the cell adhesion molecules responsible for the attachment ability of hiPSC-CMs by knockdown and over-expression experiments. Moreover, over-expression experiments using adeno-associated virus (AAV) demonstrate that hiPSC-CMs with overexpression of a cell adhesion molecule improved calcium handling and increased propagation speed, and ECTs with overexpression of a cell adhesion molecule showed enhanced sarcomere alignment and sarcomere length compared to controls.

Conclusion(s)
We observed differences in attachment ability between hiPSC-CMs generated by two differentiation methods. Transcriptome analysis of these hiPSC-CMs identified key cell adhesion molecules that regulate cell-cell attachment ability of hiPSC-CMs. Furthermore, increment of attachment ability of hiPSC-CMs by overexpression of a cell adhesion molecule enhanced hiPSC-CMs and ECT functions.
SMAD3 silencing induces Epithelial-to-Mesenchymal Transition (EMT) towards cardiac pericyte progenitors with proangiogenic potential in hiPSC-derived epicardial cells
Authors: Miyoshi Y , Lecena-Cacace A , Yoshida Y 
Published: October 2024

Abstract

Background
The epicardium is only a single mesothelial layer and "quiescent" in the adult heart. However, once the heart is injured, the epicardium reactivates and acts as a key for cardiac regeneration through epithelium-to-mesenchymal transition (EMT). While the canonical TGF-β-SMAD pathway plays a central role in regulating EMT, SMAD3 functions independent of this pathway in epicardium remain unknown.

Purpose
The purpose of this study is to investigate the effects of SMAD3 downregulation on EMT in epicardial cells.

Methods
First, we differentiated human iPSC-derived epicardial cells (EPI cells) by mimicking the process of cardiac mesoderm development. Next, siRNA targeting SMAD3 was transfected into EPI cells to silence SMAD3. We performed qRT-PCR, western blotting, immunocytochemistry, flow cytometry, transcriptional analysis, endothelial tube formation assay, and paracrine experiments using FUCCI (fluorescent ubiquitination-based cell cycle indicator) system to evaluate the phenotype of EPI cells with silenced SMAD3.

Results
We found that SMAD3 silencing in EPI cells resulted in loss of epicardial identity and upregulation of multiple EMT markers. Additionally, NG2 and ENG (CD105), both cardiac pericyte markers, were highly expressed in SMAD3-silenced EPI cells. RNA-sequence also revealed that SMAD3 silencing in EPI cells induced EMT facilitated towards cardiac pericyte progenitors with proangiogenic potential. In endothelial tube formation assay, SMAD3-silenced EPI cells demonstrated enhanced tube formation compared to the control (1.48-fold increase in the number of junctions, n=3; p&lt;0.0001), which indicated their angiogenic potential. At last, we revealed the paracrine effect of SMAD3-silenced EPI cells to enhance the proliferative reactivation in iPSC-derived cardiomyocytes by showing upregulation in CDK6/CCND1 axis and FUCCI-green.

Conclusion
Our findings demonstrate a new role of SMAD3 biology in the human epicardium, specifically in the generation of cardiac pericyte progenitor cells that contribute to better responses in angiogenesis of the heart microvasculature enabling the possibility to continue exploiting epicardial biology for effective cardiac regeneration.
The BET protein inhibitor apabetalone (RVX-208) prevents doxorubicin-induced endothelial senescence
Authors: Mohammed S A , Telesca M , Gorica E , Panteloglou G , Mongelli A , Ruschitzka F , Costantino S , Paneni F 
Published: October 2024

Abstract

Background
Accumulation of senescent endothelial cells (ECs) plays a pivotal role in cardiometabolic disorders and lifespan reduction(1). Yet, only a few senolytics are known to date, partly due to the poor grasp of the molecular mechanisms that control the senescence survival programme. Bromo-and extraterminal domain (BET) proteins, known epigenetic reader proteins, recognize acetylated histone tails and regulate gene transcription. RVX-208, an FDA-approved BET inhibitor, has shown to modulate transcriptional programs involved in inflammation, cancer, and renal disease(2). Yet, its potential role in EC senescence and cardio-oncology remains elusive.

Purpose
Our study aims to investigate whether pharmacological modulation of BET proteins by RVX-208 can mitigate doxorubicin-induced endothelial senescence.

Methods
Human aortic endothelial cells (HAECs) were exposed to different concentrations of Doxo (50nM-500nM) for 48 hours. Cell morphology changes, cell cycle arrest, senescence associated secreted phenotype (SASP) release, upregulation of SA-b gal activity, DNA damage response (gH2AX) and expression of p21, p16 and p53 were used as molecular markers of cellular senescence. Conditioned media was collected from Doxo-treated ECs and processed for molecular analyses or used for treatment of healthy, non-senescent ECs. To test whether RVX-208 exerts any senolytic or senomorphic effect, HAECs were treated with Doxo (100 nM) in presence or absence of RVX-208 (5mM-20mM) for 48 hrs. RNA-seq and proteomic profiling were performed in vehicle and Doxo-treated ECs.

Results
Doxo-treated ECs showed a dose-dependent increase in senescence markers (p16, p21 and p53) and DNA-damage response (gH2AX). FACS analysis revealed an accumulation of cells in G2/M phase in Doxo-treated ECs (100 nM). Of interest, treatment with RVX-208 (15mM) prevented the upregulation of senescent markers (p16, p21 and p53) while rescuing alterations in cell morphology and reducing the number of SA-b gal positive cells. RVX-208 prevented Doxo-induced upregulation of genes involved in inflammation, oxidative stress and mitochondrial dysfunction as shown by RNA-seq and proteomic analysis. Conditioned media from Doxo-treated ECs showed an enrichment of SASP-associated markers (IL6, CCL2, IL8, TIMP2 and PDGF-b) as shown by dot-blot arrays. Exposure of healthy ECs to conditioned media from senescent ECs recapitulated aging features. Notably, RVX-208 blunted the release of SASP markers (IL6, CCL2 and IL8) from Doxo-treated ECs. Mechanistically, we found enhanced BET protein occupancy (BRD4) with concomitant enrichment of activating chromatin marks (H3K27Ac and H3K4me) on the promoter of senescence genes COL1A2, CDKN1C and SESN3.

Conclusion
Targeting BET proteins with RVX-208 may offer a promising therapeutic strategy to prevent endothelial aging in cancer patients undergoing cardiotoxic therapies.
Exome sequencing identifies a novel FBN1 variant in a Chinese family with Marfan syndrome that includes aberrant right subclavian artery
Authors: Huang S , Lei L M , Zhang R Y 
Published: October 2024

Abstract

Background
Marfan syndrome (MFS) is an inherited autosomal dominant disorder that affects connective tissue with an incidence of about 1 in 5,000 to 10,000 people. Ninety percent of MFS is caused by mutations in the fibrillin-1 (fbn1) gene. We recruited a family with MFS phenotype in South China and identified a novel variant in fbn1 by whole exome sequencing (WES). The zebrafish share high genetic similarity to humans. This study aimed to generate this novel mutation in the fbn1 gene of zebrafish using the CRISPR/Cas9 technology and researched whether this variant is pathogenic.

Methods
A three-generation consanguineous family was recruited in this study, which was visited and interviewed for the clinical data and family history. Peripheral blood samples were collected from family members for DNA isolation and WES. The 3D structure of the protein was predicted by Alphafold. CRISPR/Cas9 was applied to generate an fbn1 nonsense mutation (fbn1+/−) in zebrafish. Morphological abnormalities were assessed in F2 fbn1+/− zebrafish by comparing with the wild-type (WT) controls at different development stages.

Results
Our study recruited a family with MFS phenotype in South China and identified a novel variant [NM_000138.5; c.7764C&gt;G: p.(Y2588*)] in fbn1. Through Sanger sequencing, we found that family members Ⅲ-1 (son) and Ⅲ-2 (daughter) had the fbn1 variant segregated with MFS in the family. The p.Y2588* mutation resulted in the absence of 283 amino acids, thereby leading to the deficiency of 17 β-folded structures, 4 α-helix structures, and various loop structures. Compared with WT zebrafish, F2 fbn1+/− zebrafish exhibited aortic arches bleeding, abnormal angiogenesis, decreased cardiac volume, cardiac function defects, curly tail, and cartilage malformations.

Conclusion
A novel variant [NM_000138.5; c.7764C&gt;G: p.(Y2588*)] was identified in fbn1 gene, which has not been reported in previous literature. The variant caused loss of function through premature protein truncation or nonsense-mediated mRNA decay. In zebrafish, we identified functional evidence of the detected nonsense mutation, which aligns with the clinical significance, suggesting a pathogenic variant of fbn1. Zebrafish as a novel, efficient tool to allow for the quick classification of unknown variants in fbn1 and improve the clinical diagnosis and treatment of MFS. It has brought the implementation of personal and precision medicine in the clinic within reach and made it possible to find patient-specific treatments.Marfanoid symptoms of the patient.Phenotypic Spectrum of fbn1+/− Zebrafish
Transcriptome-wide association study discovers functional long non-coding RNAs in coronary artery disease
Authors: Li S , Li L , Diagel A , Chen Z , Schunkert H 
Published: October 2024

Abstract

Genetically regulated long non-coding RNAs (lncRNAs) in coronary artery disease (CAD) have not been investigated. To discover CAD-relevant lncRNAs, we performed the transcriptome-wide association study (TWAS) using a subset genomic data of CARDIoGRAMplusC4D Consortium and transcriptomic data of nine CAD-relevant tissue types from Genotyped Tissue Expression (GTEx) and Stockholm-Tartu Atherosclerosis Reverse Network Engineering Task (STARNET) projects. We identified 20 lncRNAs associated with CAD in a tissue-specific fashion. The eQTL-GWAS colocalization analysis associated 15 lncRNAs with cardiometabolic traits which could bridge the lncRNA to CAD risk. The co-expression analysis identified co-expressed protein-coding genes of 16 lncRNAs and suggested their involved biological pathways. Four antisense lncRNAs from the same locus, CDH13-AS2, CDH13-AS1, CEDORA, and CTD-3253I12.1, not only shared cardiometabolic traits but also exclusively co-expressed with the host gene, CDH13. Our biological experiments using dRfxCas13d-based RNA immunoprecipitation, CRISPR/Cas9 gene knockdown, and dCas9-VP64-based transcriptional activation in endothelial cells, elucidated CDH13-AS2 as a stabilizer of CDH13 mRNA and suggested therapeutic potential of CDH13-AS2 overexpression.
Combined class I and class III antiarrhythmic effects of sotagliflozin - insights from heterologous expressions systems and atrial cardiomyocytes
Authors: Weirauch L W , Stelzle M S , Paasche A P , Prueser M P , Kraft M K , Wiedmann F W , Zaradzki M Z , Soethoff J S , Arif R A , Karck M K , Frey N F , Schmidt C 
Published: October 2024

Abstract

Background
The demand for more effective treatment options for atrial fibrillation (AF), the most common sustained arrhythmia, is driven by its direct impact on morbidity and mortality. Current therapies, such as antiarrhythmic drugs and catheter ablation, are limited by suboptimal efficacy and adverse effects or periinterventional complications. Therefore, safe and effective treatment of AF remains a major unmet clinical need. Sodium-glucose cotransporter (SGLT) inhibitors have shown promise in reducing the incidence of AF in large cardiovascular endpoint trials. However, the exact mechanisms of action remain unclear. While only two SGLT2 inhibitors are approved and clinically used in Europe, sotagliflozin, which inhibits both SGLT1 and SGLT2, might also have potential for the treatment of AF.

Purpose
This study aims to elucidate the effects of sotagliflozin on cardiac action potential formation. This understanding could optimise its clinical use, identify new targets for the treatment of atrial fibrillation and ultimately improve the quality of life of patients suffering from AF.

Methods
The effects of sotagliflozin on cardiac ionic currents were assessed using two-electrode voltage clamp measurements of several sodium and potassium channels heterologously expressed in Xenopus laevis oocytes. Subsequently, ascending concentrations of sotagliflozin were administered to isolated human atrial cardiomyocytes during patch-clamp measurements to investigate its effect on atrial action potential morphology.

Results
At a concentration of 100 µM, sotagliflozin showed significant inhibitory effects on three out of ten ion channels tested: NaV1.5 sodium channel current was reduced by 22,3 % %, hERG and KV4.3 potassium currents were reduced by 30,4 % and 22,5 % respectively. Patch-clamp experiments, performed on isolated human atrial cardiomyocytes showed a dose-dependent reduction in upstroke velocity and action potential amplitude by 20,8 % and 13,8 % at a concentration of 20 µM, reflecting class-I-antiarrhythmic effects. Furthermore, a prolongation of AP duration measured at 50 % (APD50) and 90 % (APD90) of repolarization by 57,7 % and 27,9 % at a sotagliflozin concentration of 20 µM was noted, implying additional class-III-antiarrhythmic action.

Conclusions
Sotagliflozin exerts direct inhibitory effects on heterologously expressed NaV1.5, hERG and KV4.3 channels, resulting in a reduction in upstroke velocity and action potential amplitude, as well as a prolongation of APD50 and APD90 levels in isolated human atrial cardiomyocytes. These results extend the pharmacological profile of sotagliflozin and suggest a potential role for the clinical use of combined SGLT1/SGLT2 inhibitors in the treatment of AF.
Dual inhibition of SGLT 1 and 2 alleviates intracellular sodium overload in uraemic cardiomyopathy
Authors: Young M , Miller J J J J , Shattock M J , Eykyn T R , Cullen F , Yaqoob M M , Aksentijevic D 
Published: October 2024

Abstract

Background
Chronic kidney disease (CKD) is a leading cause of mortality with the risk of developing cardiovascular disease higher than progression to kidney failure. The aetiology of uraemic cardiomyopathy is multifactorial and includes metabolic derangement. It was previously shown that elevated intracellular sodium (Nai) is causally linked to cardiac metabolic impairment and that targeting sodium homeostasis can reprogramme cardiac metabolism. Dual inhibition of sodium-glucose co-transporters (SGLT) 1 and 2 is an emerging therapy for CKD, however the impact on intracellular sodium and cardiac metabolism is yet to be elucidated.

Purpose
This study aimed to assess whether dual SGLT1/2 inhibitor sotagliflozin impacts cardiometabolic phenotype in CKD.

Methods
CKD was surgically induced by 5/6 nephrectomy in Wistar rats (n=46) for a period of 4 weeks, with chronic sotagliflozin treatment (5mg/kg) given for the last 3 weeks. Upon termination, hearts were Langendorff-perfused and studied using 31P and 23Na NMR spectroscopy (Sham n=7, CKD n=6, CKD+sotagliflozin n=5). To assess the cardiac-specific effect of the drug, acute sotagliflozin treatment (30mM) was delivered in the Langendorff perfusate to an additional group of CKD hearts (n=5). Furthermore, the effect of chronic sotagliflozin treatment on in vivo cardiac function (echocardiography n=23) and metabolic profile (1H NMR spectroscopy n=15) was assessed.

Results
CKD animals were characterized by significant renal dysfunction (2-fold increase in urea and creatinine vs sham, p&lt;0.05), and HFpEF (EF(%) sham 82±2 vs CKD 80±1 p&gt;0.05; diastolic dysfunction (E/A) sham 1.39±0.03 vs CKD 1.11±0.01, p=0.0018). Myocardial Nai was significantly elevated in CKD animals compared to sham controls (TQF 23Na 3.04±0.18 vs 2.01±0.32 arb units, p=0.03). Chronic sotagliflozin treatment didn’t impact renal or cardiac dysfunction. Neither chronic nor acute drug treatment impacted baseline CKD cardiac energetics (PCr/ATP sham 1.53±0.22, CKD 1.25±0.13, chronic 1.16±0.14, acute 1.18±0.13, p&gt;0.05; ΔGATP (kJ/mol) sham -64±4, CKD -66±8, chronic -56±1, acute -59±3, p&gt;0.05). However, both chronic and acute sotagliflozin treatment normalised the increased myocardial Nai (TQF 23Na chronic 2.17±0.12, acute 2.23±0.14 arb units, p&gt;0.05 vs sham). Chronic drug dosing altered the systemic metabolic profile of CKD animals reducing the levels of circulating triglycerides and FFA (p&lt;0.05) as well as altering metabolomic profile of liver, muscle and kidneys.

Conclusion(s)
We have shown that uraemic cardiomyopathy is characterised by HFpEF, elevated myocardial Nai and altered systemic metabolic profile. Both chronic and acute treatment with dual SGLT1/2 inhibitor sotagliflozin normalised myocardial Nai. The alleviation of Nai load could lead to improved cardiometabolic outcomes in CKD.
Reward system activation improves recovery from acute myocardial infarction
Authors: Haykin H , Haykin H , Avishai E A , Krot M K , Ghiringhelli M G , Debby-Azulay H D , Rolls A R , Gepstein L G 
Published: October 2024

Abstract

Introduction
Psychological processes play a crucial role in the recovery from acute myocardial infarction (AMI), yet the underlying mechanisms of these effects remain elusive. Here, we focused on the reward system, which mediates positively valenced emotions, motivation, and expectation and is based mainly on dopaminergic neurotransmission from the ventral tegmental area (VTA).

Purpose
The study examines the impact of activating dopaminergic neurons in the VTA following AMI in mice, aiming to understand the extent and mechanisms through which motivational brain network contribute to cardiac recovery process.

Methods
We used Designer Receptor Exclusively Activated by Designer Drugs (DREADDs) to target neuronal activity. We performed an AMI model and assessed cardiac function using cardiac magnetic resonance (CMR). We used histology, immunohistochemistry, proteomic analysis, ELISA, reverse transcription-PCR, endothelial tube formation assay, and pseudorabies-virus neuronal tracing to investigate the mechanism.

Results
Chemogenetic activation of dopaminergic neurons in the VTA significantly modified the remodeling processes by reducing scar tissue (Fig. 1a) and increased vascularization (Fig. 1b) 15 days following AMI, leading to improved left-ventricular performance compared to control (Fig. 1c). These effects were mediated through several physiological mechanisms, including alterations in immune activity, and reduced adrenergic inputs to the liver. We further demonstrate an anatomical connection between the VTA and the liver that follows AMI manifested by altered transcription of complement component 3 (C3). We established the essential role of C3 in endothelial tube formation in vitro and its necessity in the beneficial effects of VTA activation on the recovery from AMI in vivo (Fig.2).

Conclusion
These findings establish a causal connection between a motivational brain network and recovery from AMI, introducing potential new therapeutic avenues for intervention.Effects of VTA activation on cardiac recMechanism of VTA effects