Increased Expression of Inactive Rhomboid Protein 2 in Circulating Monocytes after Acute Myocardial Infarction.

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.

Impact of body mass index on worsening of diastolic function and impairment of left atrial strain in the general female urban population: a subanalysis of the Berlin female risk evaluation echocardiography follow-up study.

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/m2, 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/m2 compared with women with a BMI <25 kg/m2 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/m2 (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.

Determinants of myocardial work indices in women.

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.

Remote patient management of heart failure across the ejection fraction spectrum: A pre-specified analysis of the TIM-HF2 trial.

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.

Phasic left atrial strain to predict worsening of diastolic function: Results from the prospective Berlin Female Risk Evaluation follow-up trial.

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.

Gq-Mediated Arrhythmogenic Signaling Promotes Atrial Fibrillation.

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 Gαq/Gα11-family (Gq). Besides pro-fibrotic and pro-inflammatory effects, Gq-mediated signaling induces inositol trisphosphate receptor (IP3R)-mediated intracellular Ca2+ mobilization related to delayed after-depolarisations and AF. However, direct evidence of arrhythmogenic Gq-mediated signaling is absent. METHODS AND RESULTS: To define the role of Gq in AF, transgenic mice with tamoxifen-inducible, cardiomyocyte-specific Gαq/Gα11-deficiency (Gq-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 Gq-KO and control mice. However, inducibility and mean duration of AF episodes were significantly reduced in Gq-KO mice-both before and after vagal stimulation. To explore underlying mechanisms, left atrial cardiomyocytes were isolated from Gq-KO and control mice and electrically stimulated to study Ca2+-mobilization during excitation-contraction coupling using confocal microscopy. Spontaneous arrhythmogenic Ca2+ waves and sarcoplasmic reticulum content-corrected Ca2+ sparks were less frequent in Gq-KO mice. Interestingly, nuclear but not cytosolic Ca2+ transient amplitudes were significantly decreased in Gq-KO mice. CONCLUSION: Gq-signaling promotes arrhythmogenic atrial Ca2+-release and AF in mice. Targeting this pathway, ideally using Gq-selective, biased receptor ligands, may be a promising approach for the treatment and prevention of AF. Importantly, the atrial-specific expression of the Gq-effector IP3R confers atrial selectivity mitigating the risk of life-threatening ventricular pro-arrhythmic effects.

Myocardial Milieu Favors Local Differentiation of Regulatory T Cells.

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 TH17 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.

Serum Starvation Accelerates Intracellular Metabolism in Endothelial Cells.

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 13C-glucose or 13C-glutamine labeling for different time points reached a plateau phase of incorporation after 30 h for 13C-glucose and after 8 h for 13C-glutamine under both experimental conditions. Notably, we observed a faster label incorporation for both 13C-glucose and 13C-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.

Extracellular Matrix Protein-1 as a Mediator of Inflammation-Induced Fibrosis After Myocardial Infarction.

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.

Pregnancy and breast cancer in a patient with complicated Kawasaki Disease, as if one problem was not enough: a case report.

Background: Due to the increasing prevalence of Kawasaki Disease (KD) in adulthood, the number of women considering pregnancy is growing. There are limited data on the course of pregnancy in KD with coronary artery involvement. Case summary: We report on the pregnancy outcome of a 30-year-old woman with KD who was successfully resuscitated for ventricular tachycardia 3 years before. At that time, bypass surgery and later implantable cardioverter-defibrillator implantation were performed because of thrombotically occluded calcified giant coronary aneurysms. The pregnancy course was initially uncomplicated, however, at 31 weeks of gestation, left-sided breast cancer was diagnosed. Weighing maximum therapeutic efficacy against acceptable foetal and maternal cardiotoxic risk, our multidisciplinary team decided on neoadjuvant chemotherapy. The mother and foetus tolerated the therapy well. However, at 36 weeks of gestation, due to HELLP (haemolysis, elevated liver, low platelets) syndrome, a caesarean section had to be performed. The newborn was healthy with good APGAR (appearance, pulse, grimace, activity, respiration) scores. Three weeks after delivery, chemotherapy was restarted and at Week 4 after the caesarean section, the tumour was no more detectable. Discussion: We discuss data on pregnancy and KD and outline that pregnancy can be considered if the clinical condition is good and left ventricular function is preserved. We also address possible therapeutic approaches and care for breast cancer in pregnancy and coexisting cardiovascular disease. The extraordinary importance of interdisciplinary cooperation between different disciplines in such complex clinical disease conditions is emphasized.

Atheroprone fluid shear stress-regulated ALK1-Endoglin-SMAD signaling originates from early endosomes.

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.

Cardiac relapse of extranodal NK/T-cell lymphoma manifesting as incessant ventricular tachycardia: a case report.

Background: Cardiac tumours are rare but affected patients may present with symptoms mimicking other cardiac diseases. The most frequent symptoms include heart failure, arrhythmias, or embolic phenomena. Case summary: A 39-year-old man with a history of extranodal NK/T-cell lymphoma of the nasal type (ENKTL-NT) in clinical remission presented at our department with incessant ventricular tachycardia. The arrhythmia could only be controlled with a combination of intravenously administered beta-blockers, ajmaline, and amiodarone. Diagnostic workup excluded ischaemia, but imaging revealed a tumour located in the apex of the left ventricle. Endomyocardial biopsy confirmed the diagnosis of cardiac relapse of ENKTL-NT. Upon chemotherapy no further arrhythmias developed. Discussion: Many malignancies can metastasize into the heart. Multimodal imaging including echocardiography, cardiac magnetic resonance imaging, and a positron-emission tomography computed tomography paved the way to the diagnosis that was finally established by endomyocardial biopsy. In the present case, a cardiac metastasis from an ENKTL-NT presented with incessant ventricular tachycardia.

Resilience and Protection of Health Care and Research Laboratory Workers During the SARS-CoV-2 Pandemic: Analysis and Case Study From an Austrian High Security Laboratory.

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.

Serum starvation induces sexual dimorphisms in secreted proteins of human umbilical vein endothelial cells (HUVECs) from twin pairs.

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.

Small molecule STING inhibition improves myocardial infarction remodeling.

AIMS: Myocardial infarction (MI) is a major global cause of death. Massive cell death leads to inflammation, which is necessary for ensuing wound healing. Extensive inflammation, however, promotes infarct expansion and adverse remodeling. The DNA sensing receptor cyclic GMP-AMP synthase and its downstream signaling effector stimulator of interferon genes (cGAS-STING) is central in innate immune reactions in infections or autoimmunity. Cytosolic double-strand DNA activates the pathway and down-stream inflammatory responses. Recent papers demonstrated that this pathway is also active following MI and that its genetic targeting improves outcome. Thus, we investigated if pharmacologic pathway inhibition is protective after MI in order to test its translational potential. MAIN METHODS: We investigated novel and selective small-molecule STING inhibitors that inhibit STING palmitoylation and multimerization and thereby downstream pathway activation in a preclinical murine MI model. We assessed structural and functional cardiac remodeling, infarct expansion and fibrosis, as well as cardiomyocyte hypertrophy and the expression of inflammatory genes. KEY FINDINGS: Pharmacologic STING inhibition did not reduce mortality due to myocardial rupture in non-reperfused MI. Infarct size at day one was comparable. However, three weeks of pharmacologic STING inhibition after reperfused MI decreased infarct expansion and scarring, increased left ventricular systolic function to levels approaching normal values, and reduced myocardial hypertrophy. SIGNIFICANCE: Selective small-molecule STING inhibition after myocardial infarction has the potential to improve wound healing responses and pathological remodeling and thereby attenuate the development of ischemic heart failure.

Deficiency of inactive rhomboid protein 2 (iRhom2) attenuates diet-induced hyperlipidaemia and early atherogenesis.

AIMS: Atherosclerosis is a chronic inflammatory disease of the arterial vessel wall and anti-inflammatory treatment strategies are currently pursued to lower cardiovascular disease burden. Modulation of recently discovered inactive rhomboid protein 2 (iRhom2) attenuates shedding of tumour necrosis factor-alpha (TNF-α) selectively from immune cells. The present study aims at investigating the impact of iRhom2 deficiency on the development of atherosclerosis. METHODS AND RESULTS: Low-density lipoprotein receptor (LDLR)-deficient mice with additional deficiency of iRhom2 (LDLR-/-iRhom2-/-) and control (LDLR-/-) mice were fed a Western-type diet (WD) for 8 or 20 weeks to induce early or advanced atherosclerosis. Deficiency of iRhom2 resulted in a significant decrease in the size of early atherosclerotic plaques as determined in aortic root cross-sections. LDLR-/-iRhom2-/- mice exhibited significantly lower serum levels of TNF-α and lower circulating and hepatic levels of cholesterol and triglycerides compared to LDLR-/- mice at 8 weeks of WD. Analyses of hepatic bile acid concentration and gene expression at 8 weeks of WD revealed that iRhom2 deficiency prevented WD-induced repression of hepatic bile acid synthesis in LDLR-/- mice. In contrast, at 20 weeks of WD, plaque size, plaque composition, and serum levels of TNF-α or cholesterol were not different between genotypes. CONCLUSION: Modulation of inflammation by iRhom2 deficiency attenuated diet-induced hyperlipidaemia and early atherogenesis in LDLR-/- mice. iRhom2 deficiency did not affect diet-induced plaque burden and composition in advanced atherosclerosis in LDLR-/- mice.

Renal and hepatic function of patients with severe tricuspid regurgitation undergoing inferior caval valve implantation.

Due to progressive abdominal-venous congestion severe tricuspid regurgitation (TR) is a common cause of cardiorenal and cardiohepatic syndrome. We initiated the TRICAVAL study to compare interventional valve implantation into the inferior vena cava (CAVI) versus optimal medical therapy (OMT) in severe TR. In the present subanalysis, we aimed to evaluate the effects of CAVI on clinical signs of congestion, renal and hepatic function. TRICAVAL was an investigator-initiated, randomized trial. Twenty-eight patients with severe TR were randomized to OMT or CAVI using an Edwards Sapien XT valve. Probands who completed the 3-month follow-up (CAVI [n = 8], OMT [n = 10]) were evaluated by medical history, clinical examination, and laboratory testing at baseline, 3 and 12 months. After 3 months, the CAVI group exhibited a significant reduction of body weight (from 80.7 [69.0-87.7] kg to 75.5 [63.8-84.6] kg, p < 0.05) and abdominal circumference (from 101.5 ± 13.8 cm to 96.3 ± 15.4 cm, p ≤ 0.01) and a trend to lower doses of diuretics compared to OMT. Renal and hepatic function parameters did not change significantly. Within a short-term follow-up, CAVI led to an improvement of clinical signs of venous congestion and a non-significant reduction of diuretic doses compared to OMT.

Immuno-Electron and Confocal Laser Scanning Microscopy of the Glycocalyx.

The glycocalyx (GCX), a pericellular carbohydrate rich hydrogel, forms a selective barrier that shields the cellular membrane, provides mechanical support, and regulates the transport and diffusion of molecules. The GCX is a fragile structure, making it difficult to study by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Sample preparation by conventional chemical fixation destroys the GCX, giving a false impression of its organization. An additional challenge is to process the GCX in a way that preserves its morphology and enhanced antigenicity to study its cell-specific composition. The aim of this study was to provide a protocol to preserve both antigen accessibility and the unique morphology of the GCX. We established a combined high pressure freezing (HPF), osmium-free freeze substitution (FS), rehydration, and pre-embedding immunogold labeling method for TEM. Our results showed specific immunogold labeling of GCX components expressed in human monocytic THP-1 cells, hyaluronic acid receptor (CD44) and chondroitin sulfate (CS), and maintained a well-preserved GCX morphology. We adapted the protocol for antigen localization by CLSM and confirmed the specific distribution pattern of GCX components. The presented combination of HPF, FS, rehydration, and immunolabeling for both TEM and CLSM offers the possibility for analyzing the morphology and composition of the unique GCX structure.