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Angela Ariza de Schellenberger,1,* Wolfram C Poller,2,* Verena Stangl,2 Ulf Landmesser,3 Eyk Schellenberger1 1Department of Radiology, Charité-Universitätsmedizin Berlin, Germany; 2Department of Interventional Cardiology, Charité-Universitätsmedizin Berlin, Germany; 3Department of Cardiology, Charité- Universitätsmedizin Berlin, Berlin Institute of Health (BIH) and Deutsches Zentrum für Herz-Kreislaufforschung (DZHK), Berlin, Germany *These authors contributed equally to this work Background: Optical coherence tomography (OCT) is an intravascular, high-resolution imaging technique that is used to characterize atherosclerotic plaques. However, the identification of macrophages as important markers of inflammation and plaque vulnerability remains difficult. Here, we investigate whether the uptake of very small iron oxide particles (VSOP) in macrophages, that cluster in phagolysosomes and allow high-quality magnetic resonance imaging (MRI) of atherosclerotic plaques, and uptake of ferumoxytol nanoparticles enhance detection of macrophages by OCT.Materials and methods: RAW 264.7 macrophage cells were incubated with VSOP (1 and 2 mM Fe) that have been clinically tested and ferumoxytol (8.9 mM Fe) that is approved for iron deficiency treatment and currently investigated as an MRI contrast agent. The light scattering of control macrophages, nanoparticle-labeled macrophages (2,000,000 in 500 µL) and nanoparticle suspensions was measured in synchronous wavelength scan mode using a fluorescence spectrophotometer. For OCT analyses, pellets of 8,000,000 non-labeled, VSOP-labeled and ferumoxytol-labeled RAW 264.7 macrophages were imaged and analyzed on an OPTIS™ OCT imaging system.Results: Incubation with 1 and 2 mM VSOP resulted in uptake of 7.1±1.5 and 12±1.5 pg Fe per cell, which increased the backscattering of the macrophages in spectrophotometry 2.5- and 3.6-fold, whereas incubation with 8.9 mM Fe ferumoxytol resulted in uptake of 6.6±2 pg Fe per cell, which increased the backscattering 1.5-fold at 700 nm. In contrast, backscattering of non-clustered nanoparticles in suspension was negligible. Accordingly, OCT imaging could visualize significantly increased backscattering and signal attenuation of nanoparticle-labeled macrophages in comparison with controls.Conclusion: We conclude that VSOP and, to a lesser extent, ferumoxytol increase light scattering and attenuation when taken up by macrophages and can serve as a multimodal imaging probe for MRI and OCT to improve macrophage detection in atherosclerotic plaques by OCT in the future. Keywords: intravascular, inflammation, vulnerability, multimodal imaging, optical coherence tomography, magnetic resonance imaging

Susanne Wagner,1 Jörg Schnorr,1 Antje Ludwig,2 Verena Stangl,2 Monika Ebert,1 Bernd Hamm,1 Matthias Taupitz11Department of Radiology, Section of Experimental Radiology, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, and Campus Benjamin Franklin, Berlin, Germany; 2Department of Cardiology, Section of Experimental Cardiology, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, GermanyObjective: To evaluate the suitability of citrate-coated very small superparamagnetic iron oxide particles (VSOP) as a contrast agent for identifying inflammation in atherosclerotic lesions using magnetic resonance imaging (MRI).Methods and results: VSOP, which have already been evaluated as a blood pool contrast agent for MR angiography in human clinical trials, were investigated in Watanabe heritable hyperlipidemic rabbits to determine to what extent their accumulation in atherosclerotic lesions is a function of macrophage density and other characteristics of progressive atherosclerotic plaques. In advanced atherosclerotic lesions, a significant MRI signal loss was found within 1 hour after intravenous administration of VSOP at the intended clinical dose of 0.05 mmol Fe/kg. Histological examinations confirmed correlations between the loss of MRI signal in the vessel wall and the presence of Prussian blue-stained iron colocalized with macrophages in the plaque cap, but surprisingly also with calcifying microvesicles at the intimomedial interface. Critical electrolyte magnesium chloride concentration in combination with Alcian blue stain indicates that highly sulfated glycosaminoglycans are a major constituent of these calcifying microvesicles, which may serve as the key molecules for binding VSOP due to their highly complexing properties.Conclusion: Calcifying microvesicles and macrophages are the targets for intravenously injected VSOP in atherosclerotic plaques, suggesting that VSOP-enhanced MRI may render clinically relevant information on the composition and inflammatory activity of progressive atherosclerotic lesions at risk of destabilization.Keywords: atherosclerosis, inflammation, magnetic resonance imaging, iron oxide nanoparticles, glycosaminoglycans, calcifying microvesicles

Background: Decreased levels of circulating bone marrow-derived progenitor cells have been associated with risk factors and cardiovascular diseases. Smoking is the most important modifiable risk factor for atherosclerosis in young women. The aim of this pilot study was to assess in healthy premenopausal women without other risk factors for cardiovascular disease the influence of nicotine abuse on the number of circulating progenitor cells in relation to endothelial function.Methods: The number of endothelial progenitor cells, measured as colony-forming units in a cell-culture assay (EPC-CFU) and the number of circulating CD34 + and CD34 + /CD133 + cells, measured by flow cytometry, was estimated in 32 women at the menstrual phase of the menstrual cycle. In addition, flow-mediated dilation (FMD) was assessed as a marker for vascular function. In a subgroup of these women (n = 20), progenitor cells were also investigated at the mid-follicular and luteal phases of the menstrual cycle.Results: Compared to non-smokers, the abundance of circulating CD34 + cells was significantly lower in smoking women in the menstrual, mid-luteal, and mid-follicular phases of the menstrual cycle. The number of CD34 + progenitor cells was revealed to have significant positive correlation with FMD in young healthy women, whereas CD34 + /CD133 + progenitor cells and EPC-CFU showed no significant correlation.Conclusion: The number of CD34 + progenitor cells positively correlates with FMD in young healthy women and is decreased by smoking. [ABSTRACT FROM AUTHOR]

An abstract of the article "Role of the Ubiquitin-Proteasome System in the Development of Myocardial Hypertrophy," by K. Stangl and colleagues is presented.

Recent clinical studies comparing accelerated versus bolus administration of alteplase tissue plasminogen activator (t-PA) suggest similar thrombolytic efficacy, but reveal higher bleeding complications among older patients during the double-bolus regimen. The objective of the present study was to characterize the hemostatic profile of t-PA administered as double-bolus doses of 50 mg, at intervals of 30 minutes. Among 50 patients with acute myocardial infarction treated by double-bolus t-PA thrombolysis, coagulation and fibrinolysis parameters, as well as t-PA levels, were monitored. Monitored t-PA levels peaked at 5 and 35 minutes and were detectable within the therapeutic range even after 90 minutes. Marked systemic fibrinolytic activation was indicated by 75% depletion of both plasminogen and fibrinogen, as well as by 19-fold and 300-fold increases of fibrin degradation and fibrinogen degradation products. Plasminogen-activator inhibitor activity was completely suppressed. Pronounced procoagulant activation was reflected by a 3.4-fold increase of both factor XIIa and prothrombin fragment 1+2, and by a threefold increase of thrombin-antithrombin complex. Independent of t-PA weight dosage, fibrinolytic activation was more pronounced among older patients (> or = 63 years). We conclude that t-PA after bolus administration has a long half-life. Double-bolus regimen leads to a long-lasting systemic fibrinolytic state, which is even more remarkable among older patients--a fact that may explain the higher bleeding complications reported for this age group. [ABSTRACT FROM AUTHOR]

Background: Interventional valve implantation into the inferior vena cava (CAVI) lowers venous congestion in patients with tricuspid regurgitation (TR). We evaluated the impact of a reduction of abdominal venous congestion following CAVI on circulating immune cells and inflammatory mediators., Methods: Patients with severe TR were randomized to optimal medical therapy (OMT) + CAVI (n = 8) or OMT (n = 10). In the OMT + CAVI group, an Edwards Sapien XT valve was implanted into the inferior vena cava. Immune cells and inflammatory mediators were measured in the peripheral blood at baseline and three-month follow-up., Results: Leukocytes, monocytes, basophils, eosinophils, neutrophils, lymphocytes, B, T and natural killer cells and inflammatory markers (C-reactive protein, interferon-gamma, interleukin-2, -4, -5, -10, and tumor necrosis factor-alpha) did not change substantially between baseline and three-month follow-up within the OMT + CAVI and OMT group., Conclusion: The present data suggest that reduction of venous congestion following OMT + CAVI may not lead to substantial changes in systemic inflammation within a short-term follow-up., Clinical Trial Registration: NCT02387697., (© 2024. The Author(s).)

Increased TNF-α levels following acute myocardial infarction (AMI) contribute to impaired recovery of myocardial function. Interaction of inactive rhomboid protein 2 (iRhom2) with TNF-α converting enzyme (TACE) is required for TNF-α shedding from immune cells. We hypothesized that iRhom2 expression increases in circulating monocytes following AMI. Transcript levels of iRhom2, TACE and TNF-α were evaluated by quantitative real-time PCR in isolated monocytes of 50 AMI patients at admission (d1) and 3 days (d3) after. We observed a significant increase in levels of iRhom2 mRNA expression in monocytes between d1-3, while TNF-α and TACE mRNA expression remained unchanged. At d3, iRhom2 mRNA expression positively correlated with levels of intermediate monocytes or serum TNF-α, and negatively with LV systolic function. iRhom2 may contribute to regulation of post-infarction inflammation and is associated with LV dysfunction following AMI. iRhom2 modulation should be evaluated as a potential therapeutic strategy to attenuate cardiac remodeling following AMI., (© 2024. The Author(s).)

Objective: By incorporating myocardial deformation and afterload, novel echocardiographic myocardial work indices appear to be advantageous compared to load-dependent left ventricular (LV) deformation analyses. As such, these indices may provide a more accurate and, above all, load-independent estimation of LV function in patients with chronically increased afterload. To date however, data on the relation of these indices to clinical and conventional echocardiographic parameters are scarce., Purpose: Our aim was to evaluate the relationship between myocardial work indices and age, body mass index (BMI), NTproBNP, the clinical history of arterial hypertension and diastolic dysfunction as well as selected conventional echocardiographic parameters in women., Methods: We analyzed echocardiographic data of women included in the Berlin Female Risk Evaluation (BEFRI) trial. Global Work Index (GWI), Global Constructive Work (GCW), Global Wasted Work (GWW) and Global Work Efficiency (GWE) were calculated using commercially available software based on noninvasive pressure-strain loops. The impact of selected clinical and echocardiographic characteristics on myocardial work parameters was investigated by uni- and multivariate regression analyses., Results: A total of 224 women were included in the final analysis. 155 of them were normotensive and 69 had a history of arterial hypertension. Diastolic dysfunction was more prevalent in subjects with arterial hypertension. Study participants with arterial hypertension showed higher GWI and GCW whereas GWW and GWE did not significantly differ between groups. GCW and GWW were lower and GWE higher in the presence of normal diastolic function. In multivariate regression analyses, arterial hypertension, LV GLS, and interventricular septal thickness were significantly associated with GWI. GCW showed significant associations with the clinical history of arterial hypertension, LV GLS, age and IVRT. Similarly, LV GLS, IVRT and mitral inflow E wave deceleration time were identified to be significant determinants of GWW and GWE., Conclusion: Our data confirm that, in a randomly selected sample of the general urban female population, myocardial work parameters are predominantly determined by LV GLS. In addition, the presence of arterial hypertension was identified to be a significant determinant of GWI and GCW, but not for GWW and GWE. Finally, a prolonged LV relaxation time was significantly associated with GWW and GWE, suggesting more wasted myocardial work and lower GWE values with increasing LV relaxation time., (© 2023 Wiley Periodicals LLC.)

Background: The association of body mass index (BMI) with diastolic dysfunction (DD) is well described in the literature. However, there is conflicting evidence and long-term follow-up data regarding effects of BMI on preclinical DD and left atrial (LA) function are scarce, highlighting the importance of early detection tools, such as myocardial strain., Purpose: The aim of our study was to prospectively analyze the impact of clinical and demographic parameters, especially of BMI, on worsening of diastolic function and left atrial strain (LAS) in an urban population of women with a low prevalence of cardiovascular risk factors., Methods and Results: An extensive clinical and echocardiographic assessment comprising the analysis of phasic LAS using two-dimensional speckle-tracking echocardiography (2D STE) was performed in 258 participants of the Berlin Female Risk Evaluation (BEFRI) trial between October 2019 and December 2020 after a mean follow-up period of 6.8 years. We compared clinical and echocardiographic parameters stratifying women by BMI < or ≥25 kg/m 2 , and we analyzed the impact of demographic characteristics on the worsening of DD and LA mechanics in the longer-term follow-up using univariate and multivariate regression analyses. 248 women were suitable for echocardiographic analysis of LAS using 2D STE. After a mean follow-up time of 6.8 years, LA reservoir strain (LASr) and LA conduit strain (LAScd) were significantly reduced in participants with a BMI ≥25 kg/m 2 compared with women with a BMI <25 kg/m 2 at baseline (30 ± 8% vs. 38 ± 9%, p  < 0.0001; -14 ± 7% vs. -22 ± 8%, p  < 0.0001). 28% of the overweighted women presented a deterioration of diastolic function at the time of follow-up in contrast with only 7% of the group with a BMI <25 kg/m 2 ( p  < 0.0001). BMI remained significantly associated with LAS reductions after adjustment for other risk factors in multivariate regression analyses., Conclusion: Overweight and obesity are related to impaired LAS and to a worsening of diastolic function after a long-term follow-up in a cohort of randomly selected women., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Romero Dorta, Wolf, Hübscher, Blaschke-Waluga, Seeland, Crayen, Bischoff, Mattig, Dreger, Stangl, Regitz-Zagrosek, Landmesser, Knebel, Stangl and Brand.)

Aims: The benefit of non-invasive remote patient management (RPM) for patients with heart failure (HF) has been demonstrated. We evaluated the effect of left ventricular ejection fraction (LVEF) on treatment outcomes in the TIM-HF2 (Telemedical Interventional Management in Heart Failure II; NCT01878630) randomized trial., Methods and Results: TIM-HF2 was a prospective, randomized, multicentre trial investigating the effect of a structured RPM intervention versus usual care in patients who had been hospitalized for HF within 12 months before randomization. The primary endpoint was the percentage of days lost due to all-cause death or unplanned cardiovascular hospitalization. Key secondary endpoints were all-cause and cardiovascular mortality. Outcomes were assessed by LVEF in guideline-defined subgroups of ≤40% (HF with reduced EF [HFrEF]), 41-49% (HF with mildly reduced EF [HFmrEF]), and ≥50% (HF with preserved EF [HFpEF]). Out of 1538 participants, 818 (53%) had HFrEF, 224 (15%) had HFmrEF, and 496 (32%) had HFpEF. Within each LVEF subgroup, the primary endpoint was lower in the treatment group, i.e. the incidence rate ratio [IRR] remained below 1.0. Comparing intervention and control group, the percentage of days lost was 5.4% versus 7.6% for HFrEF (IRR 0.72, 95% confidence interval [CI] 0.54-0.97), 3.3% versus 5.9% for HFmrEF (IRR 0.85, 95% CI 0.48-1.50) and 4.7% versus 5.4% for HFpEF (IRR 0.93, 95% CI 0.64-1.36). No interaction between LVEF and the randomized group became apparent. All-cause and cardiovascular mortality were also reduced by RPM in each subgroup with hazard ratios <1.0 across the LVEF spectrum for both endpoints., Conclusion: In the clinical set-up deployed in the TIM-HF2 trial, RPM appeared effective irrespective of the LVEF-based HF phenotype., (© 2023 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Irreversible fibrosis is a hallmark of myocardial infarction (MI) and heart failure. Extracellular matrix protein-1 (ECM-1) is up-regulated in these hearts, localized to fibrotic, inflammatory, and perivascular areas. ECM-1 originates predominantly from fibroblasts, macrophages, and pericytes/vascular cells in uninjured human and mouse hearts, and from M1 and M2 macrophages and myofibroblasts after MI. ECM-1 stimulates fibroblast-to-myofibroblast transition, up-regulates key fibrotic and inflammatory pathways, and inhibits cardiac fibroblast migration. ECM-1 binds HuCFb cell surface receptor LRP1, and LRP1 inhibition blocks ECM-1 from stimulating fibroblast-to-myofibroblast transition, confirming a novel ECM-1-LRP1 fibrotic signaling axis. ECM-1 may represent a novel mechanism facilitating inflammation-fibrosis crosstalk., Competing Interests: This work was supported by the Austrian Society of Cardiology, ERA-CVD, and Austrian Science Fund AIR-MI consortium (I 4168-B to Dr Rainer); John Hunter Charitable Trust (G1800510 to Dr Boyle); Hunter Medical Research Institute and Emlyn and Jennie Thomas Postgraduate Medical Research Scholarship (G2100164 and G1800696 to Dr Boyle); Australian Commonwealth funded Research Training Program stipend (to Drs Hardy and Mabotuwana); Medical University of Graz Doctoral School of Translational Molecular and Cellular Biosciences [to Drs Hardy and Mabotuwana] and Doctoral School of Molecular Medicine [to Dr Rech]; Austrian Society of Cardiology (to Dr Hardy); National Health and Medical Research Council (NHMRC) (2000615 and 1074386 to Dr Harvey, 1079187 and 1175134 to Dr Hansbro, and 1156898 and 20000483 to Dr Starkey); NHMRC Senior Principal Research Fellowship (1118576 to Dr Harvey); Stem Cells Australia (SR110001002 to Dr Harvey); the Victor Chang Cardiac Research Institute, Australia [to Dr Harvey]; the University of Technology Sydney, Australia [to Dr Hansbro]; Monash University, Australia (to Dr Starkey); Australian Research Council (DE170100226 to Dr Starkey); Foundation Leducq (15CVD03 and 13CVD01 to Dr Harvey); Austrian Science fund (KLI645, W1226, and F73 to Dr Birner-Gruenberger); Interdisciplinary Centre for Clinical Research, University Hospital Würzburg (E-353 to Dr Cochain, E-354 to Dr Campos Ramos); the German Research Foundation [471705758 and 458539578 to Dr Cochain, DFG SFB1525 project no. 453989101 to Drs Cochain and Campos Ramos, and 411619907 to Dr Campos Ramos]; and the European Research Area Network-Cardiovascular Diseases/German Federal Ministry of Education and Research (01KL1902 to Dr Campos Ramos). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.PerspectivesCOMPETENCY IN MEDICAL KNOWLEDGE: Fibrosis is a key factor in heart disease that impedes cardiac function and prognosis. Yet, no therapies specifically target profibrotic signaling in the heart, and once established, fibrotic remodeling is largely irreversible. Inflammation-fibrosis crosstalk, whereby ECM remodeling and fibrotic tissue deposition is tightly connected to inflammation and vice versa, is now thought to be critical in orchestrating wound healing and cardiac scarring. It is suggested that this is why unidirectional therapies targeting fibrosis or inflammation alone have failed to substantially reduce the mortality associated with cardiac diseases. Here, we represent ECM-1 as a potential novel mediator of inflammation-induced fibrotic signaling in the heart and confirm its regulation in human heart failure. TRANSLATIONAL OUTLOOK: ECM-1 may serve as an attractive future treatment target to prevent excessive and detrimental fibrosis. Because fibrosis and scarring is a universal response to injury in many organs, this has potential implications beyond heart disease., (© 2023 The Authors.)

Background: In the past years, several studies investigated how distinct immune cell subsets affects post-myocardial infarction repair. However, whether and how the tissue environment controls these local immune responses has remained poorly understood. We sought to investigate how antigen-specific T-helper cells differentiate under myocardial milieu's influence., Methods: We used a transgenic T cell receptor (TCR-M) model and major histocompatibility complex-II tetramers, both myosin-specific, combined with single-cell transcriptomics (single-cell RNA sequencing [scRNA-seq]) and functional phenotyping to elucidate how the antigen-specific CD4 + T cells differentiate in the murine infarcted myocardium and influence tissue repair. Additionally, we transferred proinflammatory versus regulatory predifferentiated TCR-M-cells to dissect how they specially contribute to post-myocardial infarction inflammation., Results: Flow cytometry and scRNA-/TCR-seq analyses revealed that transferred TCR-M cells acquired an induced regulatory phenotype (induced regulatory T cell) in the infarcted myocardium and blunted local inflammation. Myocardial TCR-M cells differentiated into 2 main lineages enriched with either cell activation and profibrotic transcripts (eg, Tgfb1 ) or suppressor immune checkpoints (eg, Pdcd1 ), which we also found in human myocardial tissue. These cells produced high levels of LAP (latency-associated peptide) and inhibited IL-17 (interleukin-17) responses. Endogenous myosin-specific T-helper cells, identified using genetically barcoded tetramers, also accumulated in infarcted hearts and exhibited a regulatory phenotype. Notably, TCR-M cells that were predifferentiated toward a regulatory phenotype in vitro maintained stable in vivo FOXP3 (Forkhead box P3) expression and anti-inflammatory activity whereas T H 17 partially converted toward a regulatory phenotype in the injured myocardium. Overall, the myosin-specific Tregs dampened post-myocardial infarction inflammation, suppressed neighboring T cells, and were associated with improved cardiac function., Conclusions: These findings provide novel evidence that the heart and its draining lymph nodes actively shape local immune responses by promoting the differentiation of antigen-specific Tregs poised with suppressive function.

Purpose: The predictive value of maximum left atrial volume index (LAVI), phasic left atrial strain (LAS) and other standard echocardiographic parameters assessing left ventricular (LV) diastolic function to discriminate a future worsening of diastolic function (DD) in patients at risk is unclear. We aimed to prospectively assess and compare the clinical impact of these parameters in a randomly selected study sample of the general urban female population., Methods and Results: A comprehensive clinical and echocardiographic evaluation was performed in 256 participants of the Berlin Female Risk Evaluation (BEFRI) trial after a mean follow up time of 6.8 years. After an assessment of participants' current DD status, the predictive impact of an impaired LAS on the course of DD was assessed and compared with LAVI and other DD parameters using receiver operating characteristic (ROC) curve and multivariate logistic regression analyses. Subjects with no DD (DD0) who showed a decline of diastolic function by the time of follow-up showed a reduced LA reservoir (LASr) and conduit strain (LAScd) compared to subjects who remained in the healthy range (LASr 28.0% ± 7.0 vs. 41.9% ± 8.5; LAScd -13.2% ± 5.1 vs. -25.4% ± 9.1; p  < 0.001). With an area under the curve (AUC) of 0.88 (95%CI 0.82-0.94) and 0.84 (95%CI 0.79-0.89), LASr and LAScd exhibited the highest discriminative value in predicting worsening of diastolic function, whereas LAVI was only of limited prognostic value [AUC 0.63 (95%CI 0.54-0.73)]. In logistic regression analyses, LAS remained a significant predictor for a decline of diastolic function after controlling for clinical and standard echocardiographic DD parameters, indicating its incremental predictive value., Conclusion: The analysis of phasic LAS may be useful to predict worsening of LV diastolic function in DD0 patients at risk for a future DD development.GRAPHICAL ABSTRACT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Brand, Romero Dorta, Wolf, Blaschke-Waluga, Seeland, Crayen, Bischoff, Mattig, Dreger, Stangl, Regitz-Zagrosek, Landmesser, Knebel and Stangl.)

Background: Atrial fibrillation (AF) is promoted by various stimuli like angiotensin II, endothelin-1, epinephrine/norepinephrine, vagal activation, or mechanical stress, all of which activate receptors coupled to G-proteins of the Gα q /Gα 11 -family (G q ). Besides pro-fibrotic and pro-inflammatory effects, G q -mediated signaling induces inositol trisphosphate receptor (IP 3 R)-mediated intracellular Ca 2+ mobilization related to delayed after-depolarisations and AF. However, direct evidence of arrhythmogenic G q -mediated signaling is absent., Methods and Results: To define the role of G q in AF, transgenic mice with tamoxifen-inducible, cardiomyocyte-specific Gα q /Gα 11 -deficiency (G q -KO) were created and exposed to intracardiac electrophysiological studies. Baseline electrophysiological properties, including heart rate, sinus node recovery time, and atrial as well as AV nodal effective refractory periods, were comparable in G q -KO and control mice. However, inducibility and mean duration of AF episodes were significantly reduced in G q -KO mice-both before and after vagal stimulation. To explore underlying mechanisms, left atrial cardiomyocytes were isolated from G q -KO and control mice and electrically stimulated to study Ca 2+ -mobilization during excitation-contraction coupling using confocal microscopy. Spontaneous arrhythmogenic Ca 2+ waves and sarcoplasmic reticulum content-corrected Ca 2+ sparks were less frequent in G q -KO mice. Interestingly, nuclear but not cytosolic Ca 2+ transient amplitudes were significantly decreased in G q -KO mice., Conclusion: G q -signaling promotes arrhythmogenic atrial Ca 2+ -release and AF in mice. Targeting this pathway, ideally using G q -selective, biased receptor ligands, may be a promising approach for the treatment and prevention of AF. Importantly, the atrial-specific expression of the G q -effector IP 3 R confers atrial selectivity mitigating the risk of life-threatening ventricular pro-arrhythmic effects.

Periods of low energy supply are challenging conditions for organisms and cells during fasting or famine. Although changes in nutrient levels in the blood are first sensed by endothelial cells, studies on their metabolic adaptations to diminished energy supply are lacking. We analyzed the dynamic metabolic activity of human umbilical vein endothelial cells (HUVECs) in basal conditions and after serum starvation. Metabolites of glycolysis, the tricarboxylic acid (TCA) cycle, and the glycerol pathway showed lower levels after serum starvation, whereas amino acids had increased levels. A metabolic flux analysis with 13 C-glucose or 13 C-glutamine labeling for different time points reached a plateau phase of incorporation after 30 h for 13 C-glucose and after 8 h for 13 C-glutamine under both experimental conditions. Notably, we observed a faster label incorporation for both 13 C-glucose and 13 C-glutamine after serum starvation. In the linear range of label incorporation after 3 h, we found a significantly faster incorporation of central carbon metabolites after serum starvation compared to the basal state. These findings may indicate that endothelial cells develop increased metabolic activity to cope with energy deficiency. Physiologically, it can be a prerequisite for endothelial cells to form new blood vessels under unfavorable conditions during the process of angiogenesis in vivo.

Background: Fluid shear stress enhances endothelial SMAD1/5 signaling via the BMP9-bound ALK1 receptor complex supported by the co-receptor Endoglin. While moderate SMAD1/5 activation is required to maintain endothelial quiescence, excessive SMAD1/5 signaling promotes endothelial dysfunction. Increased BMP signaling participates in endothelial-to-mesenchymal transition and inflammation culminating in vascular diseases such as atherosclerosis. While the function of Endoglin has so far been described under picomolar concentrations of BMP9 and short-term shear application, we investigated Endoglin under physiological BMP9 and long-term pathophysiological shear conditions., Results: We report here that knock-down of Endoglin leads to exacerbated SMAD1/5 phosphorylation and atheroprone gene expression profile in HUVECs sheared for 24 h. Making use of the ligand-trap ALK1-Fc, we furthermore show that this increase is dependent on BMP9/10. Mechanistically, we reveal that long-term exposure of ECs to low laminar shear stress leads to enhanced Endoglin expression and endocytosis of Endoglin in Caveolin-1-positive early endosomes. In these endosomes, we could localize the ALK1-Endoglin complex, labeled BMP9 as well as SMAD1, highlighting Caveolin-1 vesicles as a SMAD signaling compartment in cells exposed to low atheroprone laminar shear stress., Conclusions: We identified Endoglin to be essential in preventing excessive activation of SMAD1/5 under physiological flow conditions and Caveolin-1-positive early endosomes as a new flow-regulated signaling compartment for BMP9-ALK1-Endoglin signaling axis in atheroprone flow conditions., (© 2022. The Author(s).)

The SARS-CoV-2 pandemic has highlighted the interdependency of healthcare systems and research organizations on manufacturers and suppliers of personnel protective equipment (PPE) and the need for well-trained personnel who can react quickly to changing working conditions. Reports on challenges faced by research laboratory workers (RLWs) are rare in contrast to the lived experience of hospital health care workers. We report on experiences gained by RLWs (e.g., molecular scientists, pathologists, autopsy assistants) who significantly contributed to combating the pandemic under particularly challenging conditions due to increased workload, sickness and interrupted PPE supply chains. RLWs perform a broad spectrum of work with SARS-CoV-2 such as autopsies, establishment of virus cultures and infection models, development and verification of diagnostics, performance of virus inactivation assays to investigate various antiviral agents including vaccines and evaluation of decontamination technologies in high containment biological laboratories (HCBL). Performance of autopsies and laboratory work increased substantially during the pandemic and thus led to highly demanding working conditions with working shifts of more than eight hours working in PPE that stressed individual limits and also the ergonomic and safety limits of PPE. We provide detailed insights into the challenges of the stressful daily laboratory routine since the pandemic began, lessons learned, and suggest solutions for better safety based on a case study of a newly established HCBL (i.e., BSL-3 laboratory) designed for autopsies and research laboratory work. Reduced personal risk, increased resilience, and stress resistance can be achieved by improved PPE components, better training, redundant safety measures, inculcating a culture of safety, and excellent teamwork., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Loibner, Barach, Wolfgruber, Langner, Stangl, Rieger, Föderl-Höbenreich, Hardt, Kicker, Groiss, Zacharias, Wurm, Gorkiewicz, Regitnig and Zatloukal.)

Background: Patients scheduled for coronary angiography may feel insufficiently informed about the planned procedure. We aimed to evaluate the patient-rated quality of the Informed Consent (IC) process and to investigate the efficacy of medical graphics to assist and improve the IC procedure., Methods: A graphic-based information broschure illustrating central steps of the procedure was created in collaboration with scientific illustrators. In a randomized, controlled, prospective trial, 121 patients undergoing coronary angiography/PCI were randomized to a group obtaining the usual IC (Control group) or to a group that additionally obtained a graphic-based IC (Comic group). The perceived quality of the IC was compared between groups using single items of the Client Satisfaction Questionnaire-8 and self-designed single items., Results: Only 67.8% of patients stated to have completely read the standard written IC sheet. The quality of the IC was perceived to be very good in 45.0% of patients in the Comic group compared to 24.6% in the Control group ( p =.023 ). 57.4% of the Control group compared to 76.7% of the Comic group stated that all of their questions were satisfactorily adressed ( p =.015). 43.3% of the Comic group, in contrast to only 18.0% of the Control group, declared to feel "very satisfied" with the obtained IC procedure ( p =.002 ). The acceptance of this new IC approach was very high: no patient expressed feelings of not being taken seriously when reading medical graphics., Conclusions: Our data confirm pronounced limitations of the usual IC practice. The use of medical graphics positively impacts on patient-evaluated endpoints and may significantly improve the IC procedure., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors. Published by Elsevier B.V.)

There is growing evidence for sex and gender differences in the clinical manifestation and outcomes of human diseases. Human primary endothelial cells represent a useful cardiovascular model to study sexual dimorphisms at the cellular level. Here, we analyzed sexual dimorphisms of the secretome after serum starvation using human umbilical vein endothelial cells (HUVECs) from twin pairs of the opposite sex to minimize the impact of varying genetic background. HUVECs were starved for 5 and 16 h, respectively, and proteins of the cell culture supernatants were analyzed by tandem mass spectrometry. Altogether, 960 extracellular proteins were identified of which 683 were amendable to stringent quantification. Significant alterations were observed for 455 proteins between long-term and short-term starvation and the majority were similar in both sexes. Only 5 proteins showed significant sex-specific regulation between long-versus short-term starvation. Furthermore, 19 unique proteins with significant sexual dimorphisms at the same time points of serum starvation were observed. A larger number of proteins, for example tissue factor inhibitor 2 (TFPI2), displayed higher levels in the supernatants of females compared to male cells after long term serum starvation that might point to higher adaptation capacity of female cells. The overall results demonstrate that male and female cells differ in their secretome., (© 2022 The Authors. Proteomics published by Wiley-VCH GmbH.)