bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of periodontitis and oral microbiome dysbiosis in a mouse model with heart failure with preserved ejection fraction results in worsening hypertension and diastolic dysfunction
Authors: Da'na S , Abedat S , Nachman D , Rokach Y , Qadan A , Karram S , Tzach-Nahman R , Beeri R , Amir O , Houri-Haddad Y , Asleh R 
Published: October 2022

Abstract

Introduction
Heart Failure with Preserved Ejection Fraction (HFpEF) is characterized by increased inflammation and disruption of the nitric oxide (NO) pathway. Oral microbiota has an essential role in the generation of a large portion of the NO bioavailability pool in the human body. Periodontitis (PD) is a common inflammatory condition that contributes to the development of chronic low-grade inflammation, oral microbiota dysbiosis, and dysregulation of the NO hemostasis.

Purpose
In this study, we sought to investigate the direct effect of PD induction on HFpEF manifestation in a mouse model.

Methods
HFpEF was induced in 11-week-old C57/black male mice by high-fat diet and inhibition of NO synthase using L-NAME (Nω-nitro-l-arginine-methyl-ester) (a “2-hit-model”) for 10 weeks. PD was induced by oral infection with P. gingivalis. Diastolic function of the left ventricle (LV) was assessed by high-frequency echocardiography. Blood pressure (BP) was measured using CODA non-invasive tail-cuff system.

Results
Induction of PD resulted in a significantly impaired diastolic function demonstrated by more pronounced decrease in e' and increase in E/e' ratio compared to HFpEF without PD or control mice (E/e': 39.7±2.6 vs. 30.1±1.9 vs. 24.3±2.1 for PD-HFpEF [n=15], HFpEF [n=15], and controls [n=10], respectively, p&lt;0.001). While LV ejection fraction (EF) was similar, global longitudinal strain (GLS) was decreased in the HFpEF group and further decreased in the PD-HFpEF group compared to controls (p&lt;0.001). BP was elevated in the HFpEF mice and PD induction resulted in a more remarkable increase in BP (systolic BP: 124.7±3.3 vs. 112.7±3.8 vs. 94.8±2.2 mmHg, respectively, p&lt;0.001).

Conclusions
Induction of PD in a mouse model with HFpEF results in a more pronounced BP elevation and diastolic dysfunction compared to HFpEF without PD. Extensive molecular experiments are ongoing to explore the mechanisms responsible for the increased HFpEF severity in the setting of PD.

Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): Israel Science Foundation
Human, mouse scRNA-seq and flow cytometry data in ischemic heart failure models predict immune cell activation signatures with altered endothelial cell cross talk
Authors: Merten M , Rasper T , Cremer S , Schuhmacher B , Tombor L , Zeiher A M , Hoffmann J , Abplanalp W T , Dimmeler S 
Published: October 2022

Abstract

Chronic ischemic Heart Failure (HF) with reduced ejection fraction is marked by adverse remodelling and sustained inflammation. The effects of monocytes and T cells in early state immune responses after myocardial infarction are known, to date their role in progression and maintenance of chronic HF remains elusive.
Single cell RNA sequencing of peripheral immune cells from healthy and HF donors revealed a significant increase of the antigen presentation (i.e. HLA-DRB5) and co-stimulatory molecules (i.e. ICAM-1) on monocytes, while the elevation of the T effector memory population in HF patients shows enhanced T cell activation. Subsequent flow cytometry validation in 55 healthy and 110 HF patients confirmed that HF derived monocytes have elevated levels of HLA-DRB5 predicts increased ICAM-1 and TREM-1 (p&lt;0.0001 for both), indicating enhanced T cell activation capacity. In addition, the activated fraction of both CD4+ and CD8+ T cells, including central memory, effector memory and TEMRA cells, is significantly enriched in the HF patients (p&lt;0.0001 for both) with reduction of the naïve T cells. T cell receptor (TCR) sequencing of age matched healthy and HF donors showed an increase in the relative TCR clonality in HF patients, indicating an expansion of the circulating T cells.
ScRNA-seq murine myocardial infarction (MI) time course data (day (d) 0/1/3/7/14/28/48 post-MI), found a progressive increase in Th17 cells and activated CD8+ T cells in the cardiac tissue at d48 (2.8x-, and 2.7x-fold, respectively) relative to d0. The T cell imbalance was marked by loss of immunosuppressive markers such as Lef1 (p=2e-30) in T cell clusters primarily populated by d48 relative to d0.
Mechanistically the downstream effects of the immune cell activation were analysed in the serum of HF patients, where increased levels of sICAM-1, IL-6 and TNFRI levels (1.75x-, 5.30x-, 2.63x-fold, respectively) could be detected. Furthermore, treatment of endothelial cells with the conditioning media from HF-immune cells induced capability to adhere with monocytes in a co-culture system but also decreased the checkpoint inhibitor molecule PD-L1, a known blocker of autoreactive T cells.
These data link HF with enhanced monocyte and T cell activation as well as T cell clonal expansion, along with increased T cell numbers in mouse hearts post-MI. These data suggest HF is may drive impaired resolution of inflammation in cardiac tissue and facilitate adverse remodelling and cardiac damage. Further studies will assess the specific role of chronic monocyte and T cell activation in the progression of heart failure.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): DFG -Deutsche ForschungsgemeinschaftDZHK -Deutsches Zentrum für Herzkreislauferkrankungen
Desmoglein 2 mutant mice reproduce arrhythmogenic right ventricular cardiomyopathy patients' phenotype
Authors: Zankov D , Ohno S 
Published: October 2022

Abstract

Background
Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is inherited cardiac disease with unresolved treatment. ARVC is progressive and leads to lethal arrhythmias and terminal heart failure. Most often encountered ARVC mutations are in desmosomal genes [1].

Purpose
We aimed to generate transgenic mice with exact copy of genetic defects found in Japanese cohort of ARVC patients, describe the phenotype, and identify target for curative therapy.

Methods
CRISPR/Cas9 genome editing was used to generate knock-in mice with the two most common point mutations in Japanese ARVC patients: DSG2 292R&gt;C and 494D&gt;A [2] (mouse equivalent positions are 297R and 499D, respectively). To analyze the phenotype of mice we used imaging techniques - cardiac echography and MRI as well as telemetry, treadmill, immunohistochemistry, confocal microscopy, histology, Western blot.

Results
In vivo observations of transgenic mice demonstrated inequalities in phenotypical presentation between the two mutations. Some of 297C mice (both hetero- and homozygous) died suddenly, starting from the age of 9 weeks, in contrast to surviving all 499A carriers. Dissection of suddenly died mice reveals enlarged cardiac cavities, mainly in the right heart. In addition, 297C homozygous hearts present with pale zones scattered all over the heart. Paraffin sections from this hearts stained with hematoxilin/eosin and Masson's trichrome show myocardial areas with absent myocytes, collagen accumulation and calcifications. With exception of homozygous 297C mice, spontaneous development of cardiac phenotype in Dsg2 knock-in mice starts after 25th weeks of age. Both mutant mice gradually developed cardiac dysfunction (echography and MRI, Fig. 1) and echographically visible left ventricular wall infiltrations. Heterozygous 297C mutation produces more severe phenotype that develops earlier. Similar to human ARVC, the degree of cardiac damage vary significantly. It is known from the human ARVC that physical activity aggravates the ARVC phenotype and may cause sudden cardiac death. To evaluate the effect of physical stress on the phenotype of Dsg2 knock-in mice we subjected 11 weeks old animals on treadmill exercise. Training for 8 weeks provoked development of heart failure in both 297C and 499A mutant mice, significantly earlier than natural progress of the phenotype. No mouse died suddenly. Telemetry experiment demonstrated electrical instability in 297C homozygous hearts showing conduction and rhythm abnormalities (Fig. 2). Apoptosis was detected in both mutant mice by TUNEL staining and confocal microscopy. Dsg2 protein expression was not affected by the mutations.

Conclusion
We generated mouse model of ARVC that reproduces exact genetic defect of the human disease. There are significant similarities between our model and ARVC patients' phenotype.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japanese KAKENHI funding
Divergent electrophysiologic safety profile of dapagliflozin and empagliflozin in a whole-heart model
Authors: Frommeyer G , Uphoff J , Wolfes J , Eckardt L , Ellermann C 
Published: October 2022

Abstract

Background
The SGLT2-inhibitors dapagliflozin and empagliflozin have emerged as standard therapy for the treatment of heart failure with reduced ejection fraction. However, experimental data on the electrophysiologic safety is sparse.

Purpose
Aim of this study was to characterize the safety profile of the SGLT2 inhibitors dapagliflozin and empagliflozin in a sensitive whole-heart model.

Methods
26 rabbit hearts of New Zealand white rabbits were excised and mounted to a Langendorff-apparatus. Hearts were divided up into two groups. The first group (n=12) was perfused with dapagliflozin in ascending concentrations (3, 5 and 10 μM). Further 14 hearts were treated with empagliflozin (1, 3 and 5 μM). Ventricular vulnerability was assessed by a predefined pacing protocol consisting of premature extra stimuli and burst stimulation.

Results
Dapagliflozin led to a significant reduction of the QT interval (3 μM: −27 ms, p&lt;0.01; 5 μM: −47 ms, p&lt;0.01; 10 μM: - 42 ms, p&lt;0.01), action potential duration (APD90; 3 μM: −21 ms, p&lt;0.01; 5 μM: −37 ms, p&lt;0.01; 10 μM: −24 ms, p&lt;0.01) and effective refractory periods (ERP; 3 μM: −34 ms, p&lt;0.01.; 5 μM: −49 ms, p&lt;0.01; 10 μM: −52 ms, p&lt;0.01). Spatial dispersion of repolarization was not increased after dapagliflozin treatment (3 μM: −4 ms, p=ns; 5 μM: −4 ms, p&lt;0.05; 10 μM: −8 ms, p=ns). Empagliflozin also led to a pronounced abbreviation of cardiac repolarization duration (QT: 1 μM: −28 ms, p&lt;0.01.; 3 μM: −47 ms, p&lt;0.01; 5 μM: −69 ms, p&lt;0.01; APD90: 1 μM: −27 ms, p&lt;0.01; 3 μM: −46 ms, p&lt;0.01; 5 μM: −51 ms, p&lt;0.01) and ERP (1 μM: −28 ms, p&lt;0.05; 3 μM: −40 ms, p&lt;0.01; 5 μM: −56 ms, p&lt;0.01). In contrast to dapagliflozin, empagliflozin amplified spatial dispersion of repolarization (1 μM: −3 ms, p=ns.; 3 μM: +4 ms, p&lt;0.05; 5 μM: +9 ms, p=ns). Dapagliflozin infusion did not provoke more ventricular arrhythmias (VA) compared to baseline conditions (baseline: 2 episodes; 3 μM: 6 episodes, p=ns.; 5 μM: 11 episodes, p=ns; 10 μM: 18 episodes, p=ns). In contrast, empagliflozin treatment significantly increased the occurrence of VA (baseline: 4 episodes; 1 μM: 12 episodes, p&lt;0.05.; 3 μM: 8 episodes, p=ns; 5 μM: 29 episodes, p&lt;0.05). Of note, none of the drugs provoked arrhythmias of the torsade de pointes type after lowering the potassium concentration.

Conclusion
The SGLT2 inhibitors dapagliflozin and empagliflozin shorten cardiac repolarization and effective refractory periods. While spatial dispersion remains stable after administration of dapagliflozin, empagliflozin amplifies spatial dispersion of repolarization. As a result, significantly more ventricular arrhythmias were inducible after empagliflozin treatment.

Funding Acknowledgement
Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Hans and Gertie Fischer-Foundation (to C.E.)
Disease-associated calmodulin mutations disrupt L-type Ca2+ channel (Cav1.2) activity and CaMKIIdelta phosphorylation in long QT syndrome
Authors: Helassa N , Prakash O , Gupta N , McCormick L F , Antonyuk S , Dart C 
Published: October 2022

Abstract

Introduction
Long QT Syndrome (LQTS) is a major inherited arrhythmia syndrome that can cause sudden cardiac death. Using genome sequencing in human patients, mutations in the ubiquitous calcium (Ca2+) sensor protein calmodulin (CaM) have been associated to LQTS. CaM is an ion channel regulator and can modulate the activity of the voltage-gated calcium channel (Cav1.2) and Ca2+/CaM-dependent protein kinase II (CaMKIIδ), involved in cardiac muscle contraction. However the molecular mechanism by which CaM mutations contribute to irregular heartbeats remains unclear.

Methods
Interaction of CaM proteins with Cav1.2 and CaMKIId synthetic peptides (Cav1.2-NSCaTE51–68, Cav1.2-IQ1665–1685, Cav1.2-C1627–1652, CaMKIIδ294–315,) was investigated using Isothermal Titration Calorimetry (ITC) and X-ray crystallography. Whole-cell patch clamp electrophysiology was used to determine the effect of CaM mutations on L-type Ca2+ currents and Ca2+-dependent inactivation (CDI). CaMKIIδ phosphorylation activity was determined by western blot and fluorescence kinase assay.

Results
Binding affinity of CaMKIId and Cav1.2 peptides to the LQTS-associated CaM variants was significantly reduced, up to 7-fold. Interestingly, the Cav1.2-IQ1665–1685 peptide showed a stronger binding, up to 2-fold, towards LQTS-CaM mutants. Crystal structures of Ca2+-CaM:CaMKIId294–315 showed structural alterations induced by LQTS associated mutations. In addition, we demonstrated that CaMKIIδ autophosphorylation and kinase activity can be significantly reduced by LQTS-associated CaM mutants. Electrophysiological examination of Cav1.2 function revealed that CaM mutations significantly impaired channel CDI, without affecting the voltage dependence of activation and inactivation.

Conclusions
These data demonstrate a strong correlation between LQTS-associated CaM mutations and Cav1.2 activity. We provide molecular insights into the diverse factors contributing to CaM-mediated arrhythmias.

Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Intermediate Basic Science Research Fellowship
Therapeutic potential of wild type TMEM43 overexpression in a mouse model of arrhythmogenic cardiomyopathy type 5
Authors: Lalaguna L , Lopez-Olaneta M , Villalba-Orero M , Rey-Martin A , Garcia-Pavia P , Lara-Pezzi E 
Published: October 2022

Abstract

Background and purpose
Arrhythmogenic cardiomyopathy type 5 (ACM5) is the most severe subtype of arrhythmogenic cardiomyopathy, caused by a point mutation in TMEM43 (p.S358L). Pathologically, the disease is characterised by dilation of the cardiac chambers and fibro-fatty replacement of the myocardium, which results in heart failure and sudden cardiac death. The function of TMEM43 and the molecular mechanism underlying ACM5 are very poorly understood, precluding the development of effective therapeutic options.
We have previously observed the interaction between the wild-type (WT) and pS358L forms of TMEM43, suggesting that WT-TMEM43 could quench the detrimental effects of the mutant protein by forming a heterodimer. Therefore, we propose that the overexpression of WT-TMEM43 could be beneficial for ACM5 progression.

Methods and results
Using our transgenic mouse models overexpressing either WT- or pS358L-TMEM43, we have generated a double transgenic mouse overexpressing both forms of the protein. The functional effects were analysed by echocardiography and electrocardiography at 5, 16 and 24 weeks of age. The lifespan of double transgenic (DT) mice increased by 10 weeks compared to mice overexpressing the mutant TMEM43 (p&lt;0.0001). Echocardiography results show an improved systolic function of both ventricles, as observed by an increased left ventricular ejection fraction (LVEF, p&lt;0.001) and tricuspid annular plane systolic excursion (TAPSE, p&lt;0.01), which is already evident at 16 weeks of age. This is accompanied by an improvement in cardiac conduction, with a reduced p wave duration (p&lt;0.001) and QRS duration (p&lt;0.001) and increased QRS amplitude (p&lt;0.0001) in DT mice compared to the mutant mice. In addition, histological analysis of heart samples shows a reduced fibrotic content in the myocardium of DT mice at 24 weeks of age (p&lt;0.0001). Furthermore, the delayed raise in serum cardiac troponin I levels suggests cardiomyocyte necrosis is also delayed in the therapeutic mouse model.

Conclusion
Overall, this data provides evidence that an overexpression of WT-TMEM43 delays the onset of ACM5 phenotype and could potentially be a novel therapeutic approach for ACM5.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Spanish Ministry of Science and Innovation
Association between inflammation and left ventricular thrombus formation following ST-elevation myocardial infarction
Authors: Holzknecht M , Lechner I , Reindl M , Tiller C , Fink P , Mayr A , Klug G , Bauer A , Reinstadler S J , Metzler B 
Published: October 2022

Abstract

Background
Current evidence suggests a link between the inflammatory state and left ventricular thrombus (LVT) formation following ST-elevation myocardial infarction (STEMI). However, a comprehensive study investigating the association between inflammatory biomarkers and LVT diagnosed by cardiac magnetic resonance (CMR) is lacking.

Purpose
The present study aimed to investigate the association of biochemical markers of inflammation with LVT as assessed by CMR imaging among patients with STEMI.

Methods
We studied 309 patients with acute STEMI treated with primary percutaneous coronary intervention (pPCI) from the prospective MARINA-STEMI cohort study. Concentrations of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), white blood cell count (WBCc), fibrinogen and D-dimer were measured two days after STEMI. Infarct characteristics and presence of LVT were assessed with the use of contrast-enhanced CMR at a median of 4 (interquartile range [IQR] 3–5) days after pPCI.

Results
In total, 309 STEMI patients (18% female) with a median age of 57 (IQR 52–65) years were included. An LVT was observed in 8% (n=24) of the overall cohort and in 15% of patients with an anterior STEMI. Hs-CRP (OR: 2.16, 95% CI: 1.54–3.02, p&lt;0.001), IL-6 (OR: 2.38, 95% CI: 1.48–3.81, p&lt;0.001) and fibrinogen levels (OR: 2.05, 95% CI: 1.40–3.00, p&lt;0.001) were significantly associated with presence of LVT. Among all assessed inflammatory biomarkers, only hs-CRP was independently associated with LVT after adjustment for markers of inflammation and CMR parameters (OR: 1.77, 95% CI: 1.21–2.59, p=0.004).

Conclusion
In patients with STEMI treated with pPCI, inflammatory markers (hs-CRP, IL-6 and fibrinogen) are associated with the presence of LVT. However, only hs-CRP was independently associated with the occurrence of LVT, highlighting the key role of CRP as clinical risk marker for LVT formation in STEMI patients treated with pPCI.

Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): Austrian Science Fund (FWF)Austrian Society of Cardiology
Pathogenic variants damage cell compositions and single cell transcription in cardiomyopathies
Authors: Reichart D , Lindberg E L , Maatz H , Miranda A , Viveiros A , Shvetsov N , Lee M , Kanemaru K , Milting H , Noseda M , Oudit G , Heinig M , Seidman J G , Huebner N , Seidman C E 
Published: October 2022

Abstract

Pathogenic variants in genes that cause dilated (DCM) and arrhythmogenic cardiomyopathies (ACM) convey high risks for the development of heart failure (HF) through unknown mechanisms. Using single nucleus RNA sequencing (snRNAseq), we characterized the transcriptome of 880,000 nuclei from 18 control and 61 failing, non-ischemic human hearts with pathogenic variants in DCM and ACM genes or idiopathic disease. We performed genotype-stratified analyses of the ventricular cell lineages and transcriptional states. The resultant DCM and ACM ventricular cell atlas demonstrated distinct right and left ventricular responses, highlighting genotype-associated pathways, intercellular interactions, and differential gene expression at single cell resolution. Together these data illuminate both shared and distinct cellular and molecular architectures of human HF and suggest novel candidate therapeutic targets.

Funding Acknowledgement
Type of funding sources: Other. Main funding source(s): Chan Zuckerberg FoundationLeducq Foundation
DNA damage induced by radiation exposure from cardiac catheterization – an analysis in patients and operators
Authors: Ishida T , Jin Y , Yaegashi D , Ishida M , Sakai C , Yamaki T , Nakazato K , Tashiro S , Takeishi Y 
Published: October 2022

Abstract

Background
The biological effects of low-dose radiation from cardiac imaging or intervention remain largely unknown. This study aimed to evaluate the effects of ionized radiation from cardiac catheterization on genomic DNA integrity and inflammatory cytokines in patients and operators.

Methods
Peripheral mononuclear cells (MNCs) were isolated from patients (n=52) and operators (n=35) before and after coronary angiography and/or percutaneous coronary intervention. Expression of gammaH2AX, a marker for DNA double-strand breaks, was measured by immunofluorescence. Dicentric chromosomes (DICs), a form of chromosome aberrations, were assayed using a fluorescent in situ hybridization technique.

Results
In the patient MNCs, the numbers of gammaH2AX foci and DICs increased after cardiac catheterization by 101±75% and 28±99%, respectively (P&lt;0.05 for both). The mRNA expressions of interleukin (IL)-1α, IL-1β, leukemia inhibitory factor (LIF) and caspase-1 were significantly increased by radiation exposure from cardiac catheterization. The increase in IL-1β was significantly correlated with that of gammaH2AX, but not with dose area product. In the operators, neither gammaH2AX foci nor DICs level was changed, but IL-1β mRNA was significantly increased. Protein expression of IkappaBα was significantly decreased in both groups.

Conclusions
DNA damage was increased in the MNCs of patients, but not of operators, who underwent cardiac catheterization. Inflammatory cytokines were increased both in the patients and operators, presumably through activation of NF-kappaB. Further efforts to reduce radiation exposure from cardiac catheterization are necessary both for patients and operators.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grants-in-Aid for Scientific Research (KAKENHI)