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Injectable extracellular matrix (iECM) is a versatile biological material with beneficial properties such as good degradability, promotion of cell survival, immunomodulation, and facilitation of vascular formation. However, intravenous injection of iECM faces challenges like a short retention time in vivo and low concentration at the lesion site. To address these issues, we prepared a composite hydrogel composed of sodium alginate and iECM and administered it via intrapericardial injection, forming a structure akin to cardiac patches within the pericardium. Compared with intramyocardial injection, intrapericardial injection avoids direct myocardial injury and ectopic tumor formation, offering less invasiveness and better biocompatibility. This study demonstrates that the sodium alginate/infusible extracellular matrix (SA/iECM) composite hydrogel can effectively prolong the local retention time of iECM in the heart, enhance electrical conduction between cardiomyocytes, promote angiogenesis at ischemic myocardial sites, inhibit apoptosis in the infarcted region, mitigate left ventricular remodeling postmyocardial infarction (MI), and improve cardiac function after infarction. Precise coordination of cardiomyocyte contraction and relaxation depends on the rhythmic occurrence of calcium-dependent action potentials. Cardiac dysfunction is partially attributed to the disruption of the excitation-contraction coupling (ECC) mechanism, which is associated with prolonged intracellular Ca 2+ transients and alterations in contraction and relaxation Ca 2+ levels. Our results show that the SA/iECM composite hydrogel improves electrical conduction, as evidenced by increased Cx43 expression and enhanced intercellular electrical connectivity. This research establishes that intrapericardial injection of a SA/iECM composite hydrogel is a safe and effective treatment modality, providing a theoretical basis for the use of biomaterials in MI therapy.

Background: Sodium-glucose cotransporter 2 inhibitors (SGLT-2i) are glucose-lowering agents used for the treatment of type 2 diabetes mellitus, which also improve heart failure and decrease the risk of cardiovascular complications. Epicardial adipose tissue (EAT) dysfunction was suggested to contribute to the development of heart failure. We aimed to elucidate a possible role of changes in EAT metabolic and inflammatory profile in the beneficial cardioprotective effects of SGLT-2i in subjects with severe heart failure., Methods: 26 subjects with severe heart failure, with reduced ejection fraction, treated with SGLT-2i versus 26 subjects without treatment, matched for age (54.0 ± 2.1 vs. 55.3 ± 2.1 years, n.s.), body mass index (27.8 ± 0.9 vs. 28.8 ± 1.0 kg/m 2 , n.s.) and left ventricular ejection fraction (20.7 ± 0.5 vs. 23.2 ± 1.7%, n.s.), who were scheduled for heart transplantation or mechanical support implantation, were included in the study. A complex metabolomic and gene expression analysis of EAT obtained during surgery was performed., Results: SGLT-2i ameliorated inflammation, as evidenced by the improved gene expression profile of pro-inflammatory genes in adipose tissue and decreased infiltration of immune cells into EAT. Enrichment of ether lipids with oleic acid noted on metabolomic analysis suggests a reduced disposition to ferroptosis, potentially further contributing to decreased oxidative stress in EAT of SGLT-2i treated subjects., Conclusions: Our results show decreased inflammation in EAT of patients with severe heart failure treated by SGLT-2i, as compared to patients with heart failure without this therapy. Modulation of EAT inflammatory and metabolic status could represent a novel mechanism behind SGLT-2i-associated cardioprotective effects in patients with heart failure., (© 2024. The Author(s).)

Purpose: This study aims to decellularized caprine pericardium tissue with varied non-ionic surfactant and anionic detergent concentrations., Methods: Protocol A consists of 1%, 0.5%, and 0.25% (w/v) sodium dodecyl sulphate (SDS). Protocol B uses 1%, 0.5%, and 0.25% (w/v) Triton X-100. Protocol C comprised 0.5% SDS + 0.5% Triton X-100, 0.5% + 0.25%, and 0.25% SDS + 0.5% Triton X-100., Results: Protocol B left a few countable cells in the pericardium tissue, but treatments A and C removed all cells. DNA quantification also demonstrated that protocol B had the most leftover DNA after decellularization. The pericardium tissue treated with an equal combination of anionic detergent and non-ionic surfactant preserves the matrix. However, changing the anionic detergent-non-ionic surfactant ratio disrupted the microstructure. Protocol A decreased pericardium tissue secant modulus (p < 0.05). Protocol B-treated pericardium tissue matched native tissue secant modulus and ultimate tensile stress. Protocol C strengthened pericardium tissue., Conclusion: The intact extracellular matrix and biomechanical properties like native tissues require optimal chemical doses and combinations., (© 2024. The Author(s) under exclusive licence to Biomedical Engineering Society.)

New Findings: What is the central question of this study? Can the triangular appearance of ventricular action potential, indicating proarrhythmic profile of antiarrhythmic agent, be approximated by specific changes on an electrocardiogram (ECG)? What are the main finding and its importance? The triangulation of the ventricular action potential seen when antiarrhythmic drugs induce a greater lengthening of the late repolarization compared to the initial repolarization in epicardium is closely approximated by a greater prolongation of the T wave upslope relative to the interval between the J point and the start of the T wave (the JT start interval) on the ECG. These findings may improve the power of ECG assessments in predicting the drug-induced arrhythmia resulting from slowed phase 3 repolarization., Abstract: Antiarrhythmic drugs prescribed to treat atrial fibrillation can occasionally precipitate ventricular tachyarrhythmia through a prominent slowing of the phase 3 repolarization. The latter results in the triangular shape of ventricular action potential, indicating high arrhythmic risk. However, clinically, the utility of triangulation assessments for predicting arrhythmia is limited owing to the invasive nature of the ventricular action potential recordings. This study examined whether the triangulation effect can be detected indirectly from electrocardiogram (ECG) analysis. Epicardial monophasic action potentials and the ECG were simultaneously recorded in perfused guinea-pig hearts. With antiarrhythmics (dofetilide, quinidine, procainamide and flecainide), a prolongation of the initial repolarization seen in the action potential recordings was closely approximated by lengthening of the interval between the J point and the start of the T wave (the JT start interval) on the ECG, whereas a prolongation of the late repolarization was paralleled by widening of the T wave upslope. Dofetilide, quinidine and procainamide induced a prominent slowing of the phase 3 repolarization in epicardium, leading to triangulation of the action potential. These effects were accompanied by a greater prolongation of the T wave upslope compared to the JT start interval. Flecainide elicited a proportional prolongation of the initial and the late ventricular repolarization, and therefore failed to induce triangulation, based on analysis of both epicardial action potential and ECG profiles. Collectively, these findings suggest that the ratio between the durations of the T wave upslope and the JT start interval may represent the ECG metric of the ventricular action potential triangulation induced by antiarrhythmic drugs., (© 2022 The Authors. Experimental Physiology © 2022 The Physiological Society.)

Bioprosthetic heart valves (BHV) fabricated from glutaraldehyde-fixed heterograft tissue, such as bovine pericardium (BP), are widely used for treating heart valve disease, a group of disorders that affects millions. Structural valve degeneration (SVD) of BHV due to both calcification and the accumulation of advanced glycation end products (AGE) with associated serum proteins limits durability. We hypothesized that BP modified with poly-2-methyl-2-oxazoline (POZ) to inhibit protein entry would demonstrate reduced accumulation of AGE and serum proteins, mitigating SVD. In vitro studies of POZ-modified BP demonstrated reduced accumulation of serum albumin and AGE. BP-POZ in vitro maintained collagen microarchitecture per two-photon microscopy despite AGE incubation, and in cell culture studies was associated with no change in tumor necrosis factor-α after exposure to AGE and activated macrophages. Comparing POZ and polyethylene glycol (PEG)-modified BP in vitro, BP-POZ was minimally affected by oxidative conditions, whereas BP-PEG was susceptible to oxidative deterioration. In juvenile rat subdermal implants, BP-POZ demonstrated reduced AGE formation and serum albumin infiltration, while calcification was not inhibited. However, BP-POZ rat subdermal implants with ethanol pretreatment demonstrated inhibition of both AGE accumulation and calcification. Ex vivo laminar flow studies with human blood demonstrated BP-POZ enhanced thromboresistance with reduced white blood cell accumulation. We conclude that SVD associated with AGE and serum protein accumulation can be mitigated through POZ functionalization that both enhances biocompatibility and facilitates ethanol pretreatment inhibition of BP calcification., Competing Interests: The authors declare no competing interest., (Copyright © 2022 the Author(s). Published by PNAS.)

Background: This study reports the long-term outcomes using glutaraldehyde-treated cryopreserved homograft pericardium (CPH) in neonates, infants, children, and young adults undergoing congenital cardiac surgery., Methods: A retrospective review was performed of all patients at a single institution (Rady Children's Hospital, San Diego, CA) who had undergone surgical implantation with CPH between 2006 and 2016. The study identified 134 consecutive patients who underwent implantation of a total of 276 patches. The baseline demographic characteristics, primary cardiac diagnosis, surgical characteristics, operative reports, and postoperative catheterization and reoperation reports were analyzed. The use of CPH was categorized by specific anatomic insertion site., Results: The median age at patch implantation was 1.47 years (range, 1 day to 31.6 years). The numbers and locations of patch use were 124 for pulmonary arterial repair, 57 for repair of the aorta, 49 for septal repair, and 43 at other sites. At a median follow-up of 5.29 years, 9 patients had died (6.7%), but none of those deaths were related to CPH. Twelve patients (8.96%) underwent reoperations, and 18 patients (13.4%) underwent catheter interventions at sites of CPH implantation. The 10-year freedom from patch-induced reoperation and catheter intervention rates were 88.5% and 86.9%, respectively. Overall patch failure-free survival was 85.8% and 79.0% at 5 and 10 years, respectively., Conclusions: The use of CPH patch in the surgical correction of congenital heart disease is effective and durable, as evidenced by the low reintervention rates. These results are comparable to the early and midterm outcomes of other similarly used surgical patches., (Copyright © 2022 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Triphenyl phosphate (TPHP) is an organophosphate ester-based plasticizer and flame retardant. The objective of this study was to identify the potential role of epidermal ionocytes in mediating TPHP-induced pericardial edema within zebrafish embryos. Exposure to TPHP from 24 to 72 h post fertilization (hpf) resulted in a significant increase in pericardial edema and the number of ionocytes at 72 hpf relative to time-matched embryos treated with vehicle. In addition, co-exposure of embryos to mannitol (an osmotic diuretic) blocked TPHP-induced pericardial edema and effects on ionocyte abundance. However, knockdown of ATPase1a1.4 - an abundant Na + /K + -ATPase localized to epidermal ionocytes - mitigated TPHP-induced effects on ionocyte abundance but not pericardial edema, whereas co-exposure of embryos to ouabain - a Na + /K + -ATPase inhibitor - enhanced TPHP-induced pericardial edema but not ionocyte abundance. Overall, our findings suggest that TPHP may have multiple mechanisms of toxicity leading to an increase in ionocyte abundance and pericardial edema within developing zebrafish embryos., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Improved understanding of the interconnectedness of structural remodeling processes in atrial fibrillation (AF) in patients could identify targets for future therapies., Methods: We present transcriptome sequencing of atrial tissues of patients without AF, with paroxysmal AF, and persistent AF (total n = 64). RNA expression levels were validated in the same and an independent cohort with qPCR. Biological processes were assessed with histological and immunohistochemical analyses., Results: In AF patients, epicardial cell gene expression decreased, contrasting with an upregulation of epithelial-to-mesenchymal transition (EMT) and mesenchymal cell gene expression. Immunohistochemistry demonstrated thickening of the epicardium and an increased proportion of (myo)fibroblast-like cells in the myocardium, supporting enhanced EMT in AF. We furthermore report an upregulation of endothelial cell proliferation, angiogenesis, and endothelial signaling. EMT and endothelial cell proliferation concurred with increased interstitial (myo)fibroblast-like cells and extracellular matrix gene expression including enhanced tenascin-C, thrombospondins, biglycan, and versican. Morphological analyses discovered increased and redistributed glycosaminoglycans and collagens in the atria of AF patients. Signaling pathways, including cell-matrix interactions, PI3K-AKT, and Notch signaling that could regulate mesenchymal cell activation, were upregulated., Conclusion: Our results suggest that EMT and endothelial cell proliferation work in concert and characterize the (myo)fibroblast recruitment and ECM remodeling of AF. These processes could guide future research toward the discovery of targets for AF therapy., (© 2021 The Authors. Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

Diabetes mellitus (DM) is a chronic and complex metabolic disorder and also an important cause of cardiovascular (CV) disease (CVD). Patients with type 2 DM (T2DM) and obesity show a greater propensity for visceral fat deposition (and excessive fat deposits elsewhere) and the link between adiposity and CVD risk is greater for visceral than for subcutaneous (SC) adipose tissue (AT). There is growing evidence that epicardial AT (EAT) and pericardial AT (PAT) play a role in the development of DM-related atherosclerosis, atrial fibrillation (AF), myocardial dysfunction, and heart failure (HF). In this review, we will highlight the importance of PAT and EAT in patients with DM. We also consider therapeutic interventions that could have a beneficial effect in terms of reducing the amount of AT and thus CV risk. EAT is biologically active and a likely determinant of CV morbidity and mortality in patients with DM, given its anatomical characteristics and proinflammatory secretory pattern. Consequently, modification of EAT/PAT may become a therapeutic target to reduce the CV burden. In patients with DM, a low calorie diet, exercise, antidiabetics and statins may change the quantity of EAT, PAT or both, alter the secretory pattern of EAT, improve the metabolic profile, and reduce inflammation. However, well-designed studies are needed to clearly define CV benefits and a therapeutic approach to EAT/PAT in patients with DM.

Purpose: The aim of this study was to analyze the effects of 10-minute (standard term) versus 20-minute treatment with glutaraldehyde (GA) on mechanical stability and physical strength of human pericardium in the setting of the OZAKI procedure., Methods: Leftover pericardium (6 patients) was bisected directly after the operation, and one-half was further fixed for 10 additional minutes. Uniaxial tensile tests were performed and ultimate tensile strength (UTS), ultimate tensile strain (uts), and collagen elastic modulus were evaluated., Results: Both treatments resulted in similar values of uniaxial stretching-generated elongations at rupture (10 minutes 25 ± 7 % vs. 20 minutes: 22 ± 5 %; p = 0.05), UTS (5.16 ± 2 MPa vs. 6.54 ± 3 MPa; p = 0.59), and collagen fiber stiffness (elastic modulus: 31.80 ± 15.05 MPa vs. 37.35 ± 15.78 MPa; p = 0.25)., Conclusion: Prolongation of the fixation time of autologous pericardium has no significant effect on its mechanical stability; thus, extending the intraoperative treatment cannot be recommended.

(1) Sodium-glucose cotransporter-2 inhibitors (SGLT2-i) reduce adipose tissue and cardiovascular events in patients with type 2 diabetes (T2D). Accumulation of epicardial adipose tissue (EAT) is associated with increased cardio-metabolic risks and obstructive coronary disease events in patients with T2D. (2) We performed a systematic review and meta-analysis of SGLT2-i therapy on T2D patients, reporting data on changes in EAT after searching the PubMed/MEDLINE, Embase, Science Direct, Scopus, Google Scholar, and Cochrane databases. A random effects or fixed effects model meta-analysis was then applied. (3) Results: A total of three studies ( n = 64 patients with SGLT2-i, n = 62 with standard therapy) were included in the final analysis. SGLT2 inhibitors reduced EAT (SMD: -0.82 (-1.49; -0.15); p < 0.0001). An exploratory analysis showed that HbA1c was significantly reduced with SGLT2-i use, while body mass index was not significantly reduced with this drug. (4) Conclusions: This meta-analysis suggests that the amount of EAT is significantly reduced in T2D patients with SGLT2-i treatment.

Abstract: Epicardial adipose tissue (EAT) dysfunction mediates chronic inflammation by regulating inflammation-related adipokines and cytokines, and it further promotes coronary artery disease (CAD) development. CD40L/CD40 is involved in multiple inflammatory pathways that contribute to various pathophysiological processes. However, the function of CD40L/CD40 in the expression and production of adipokines and cytokines in epicardial adipocytes remains unclear. The purpose of the present study was to explore the role and underlying mechanisms of CD40L/CD40 in adipokine and cytokine expression and production. We isolated adipocytes from EAT tissues of CAD and non-CAD patients. We noticed that CD40 was dramatically increased in EAT tissues of CAD patients. Loss-of-function and gain-of-function studies were performed. The results showed that CD40 silencing reduced recombinant CD40 ligand (rCD40L)-induced upregulation of plasminogen activator inhibitor-1, leptin, interleukin-6, and monocyte chemotactic protein-1 messenger RNA levels and secretion. Overexpression of CD40 displayed the opposite results. In addition, rCD40L triggered mixed lineage leukemia protein-1 (MLL1) expression both in messenger RNA and protein levels. CD40 depletion apparently blocked MLL1 expression, whereas gain of function of CD40 resulted in augmentation of MLL1 levels. Interestingly, chromatin immunoprecipitation-quantitative real-time polymerase chain reaction analysis revealed that CD40 elimination dampened histone H3 lysine 4 trimethylation enrichment at plasminogen activator inhibitor-1, leptin, interleukin-6, and monocyte chemotactic protein-1 promoter regions in the presence of rCD40L. The reverse pattern was observed upon ectopic expression of CD40. Most important, MLL1 silencing effectively reversed the promotive effects of CD40 on adipokine and cytokine secretion. Taken together, our findings suggest that CD40L/CD40 regulates adipokine and cytokine expression by H3 lysine 4 trimethylation modification in adipocytes., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Over the years, several devices have been created (and the development of many others is currently in progress) to be in permanent contact with blood: mechanical circulatory supports represent an example thereof. The hemocompatibility of these devices largely depends on the chemical composition of blood-contacting components. In the present work, an innovative material (hybrid membrane) is proposed to fabricate the inner surfaces of a pulsatile ventricular chamber: it has been obtained by coupling a synthetic polymer (e.g., commercial polycarbonate urethane) with decellularized porcine pericardium. The hemocompatibility of the innovative material has been preliminarily assessed by measuring its capacity to promote thrombin generation and induce platelet activation. Our results demonstrated the blood compatibility of the proposed hybrid membrane., (© 2021. The Author(s).)

The epicardium plays an important role in cardiomyogenesis during development, while it becomes quiescent in adult heart during homeostasis. This study investigates the efficiency of thymosin β4 (Tβ4) release with RPRHQGVM conjugated to the C-terminus of RADA16-I (RADA-RPR), the functionalized self-assembling peptide (SAP), to activate the epicardium and repairing the infarcted myocardium. Methods: The functionalized SAP was constituted with self-assembling motif, Tβ4-binding site, and cell adhesive ligand. Myocardial infarction (MI) models of the transgenic mice were established by ligation of the left anterior descending coronary artery. At one week after intramyocardial injection of Tβ4-conjugated SAP, the activation of the epicardium was assessed. At four weeks after implantation, the migration and differentiation of epicardium-derived cells (EPDCs) as well as angiogenesis, lymphangiogenesis and myocardial regeneration were examined. Results: We found that the designer RADA-RPR bound Tβ4 and adhered to EPDCs and that Tβ4 released from the functionalized SAP could effectively activate the epicardium and induce EPDCs to differentiate towards cardiovascular cells as well as lymphatic endothelial cells. Moreover, SAP-released Tβ4 (SAP-Tβ4) promoted proliferation of cardiomyocytes. Furthermore, angiogenesis, lymphangiogenesis and myocardial regeneration were enhanced in the MI models at 4 weeks after delivery of SAP-Tβ4 along with attenuation of adverse myocardial remodeling and significantly improved cardiac function. Conclusions: These results demonstrate that sustained release of Tβ4 from the functionalized SAP can activate the epicardium and effectively enhance the repair of infarcted myocardium. We believe the delivery of SAP-Tβ4 may be a promising strategy for MI therapy., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The environmental effects of additives have attracted increasing attention. Sodium dehydroacetate (DHA-S), as an approved preservative, is widely added in processed foods, cosmetics and personal care products. However, DHA-S has been recently reported to induce hemorrhage and coagulation aberration in rats. Yet little is known about the ecotoxicological effect and underlying mechanisms of DHA-S. Here, we utilized the advantage of zebrafish model to evaluate such effects. DHA-S induced cerebral hemorrhage, mandibular dysplasia and pericardial edema in zebrafish after 24 h exposure (48-72 hpf) at 50 mg/L. We also observed the defective heart looping and apoptosis in DHA-S-treated zebrafish through o-dianisidine and acridine orange staining. Meanwhile, DHA-S induced the deficiency of Ca 2+ and vitamin D3 in zebrafish. We further demonstrated that DHA-S stimulated Ca 2+ influx resulting in Ca 2+ -dependent mitochondrial damage in cardiomyocytes. Additionally, DHA-S inhibited glucose uptake and repressed the biosynthesis of amino acids. Finally, we identified that sodium bicarbonate could rescue zebrafish from DHA-S induced cardiovascular toxicity. Altogether, our results suggest that DHA-S is a potential risk for cardiovascular system., (Copyright © 2020. Published by Elsevier Inc.)

Abstract: Embryonic epicardial cells make an important contribution to cardiac development. However, their proliferation mechanism is still unclear. Epicardial cells from E12.5 fetal hearts were used in our study. Agrin was used to treat these cells. The expression of Aurora B, Ki67, and pH3 was measured by quantitative reverse transcription-polymerase chain reaction and immunofluorescence. The proportion of cells in G1/S/G2 phase was determined by flow cytometry. The results showed that agrin significantly increased the expression of ki67, pH3, and Aurora B in epicardial cells. Flow cytometry results showed that agrin significantly increased the proportion of epicardial cells in S phase. However, blocking yes-associated protein significantly downregulated the levels of ki67, pH3, and Aurora B and the proportion of epicardial cells in S phase. Thus, our results suggest that agrin may promote the proliferation of epicardial cells by regulating the yes-associated protein activity. This may be useful in exploring heart development mechanisms and preventing congenital heart disease., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Due to its pronounced regenerative capacity, the zebrafish heart represents an advantageous model system for exploring the cellular and molecular mechanisms of cardiac regeneration. Upon injury, the epicardium, the outermost mesothelial tissue layer of vertebrate hearts, serves dual purposes in the regenerating heart as both a signaling center and a source for crucial cell types. Traditional in vivo genetic approaches to study heart regeneration can be time consuming and are not applicable to large-scale approaches and live surveillance of cellular behaviors. Here, we demonstrate ex vivo methods to culture, maintain, and study the regenerative responses of epicardial tissue in excised zebrafish hearts. Epicardial cell proliferation and migration are monitored in real time after uninjured or injured hearts are excised, washed, and cultured for up to 30 days. In addition to these techniques, we describe ex vivo genetic ablation of the epicardium, cell proliferation assays, partial ventricular explant culturing, and chemical screening.

The decline of the Bombus population is closely related to the presence of environmental pollutants. Among these pollutants, trace metals represent a major concern, which includes mercury, a known genotoxic substance. The induction of genotoxicity may be demonstrated by the comet assay (a.k.a. single-cell gel electrophoresis), a simple and sensitive method for DNA damage estimating. The current work provided, for the first time, a protocol of comet assay for Bombus atratus using mercury as a standard chemical at safe concentrations according to the Environment National Council of Brazil, and the World Health Organization. Bees were collected and divided into three groups (n = 11 each), in which the exposed groups received a 0.2 ppb or a 1 ppb of mercury solution, and the control group received water. The bioassay was performed for 48 h at controlled temperature and humidity conditions, according to the OECD guideline toxicological test method for B. terrestris. The samples were stained with different dyes to observe the efficacy of each one. Variations of parameters in methodology, such as concentration and time of exposure to lysis solution as well as the electrophoretic process, allowed the observation of comets at different levels. DAPI and acridine orange presented an unstable fluorescence, and silver nitrate dye was more effective. Therefore, the comet assay was shown to be an effective method to evaluate genotoxic effects in bees. The obtained results may be helpful for the establishment of a suitable protocol for future genotoxicity assessment in neotropical bees using different doses of xenobiotics., Competing Interests: Declaration of competing interest 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., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Aim: Epicardial adipose tissue (EAT) may be associated with arrhythmogenesis. P-wave indices such as P-wave dispersion and P-wave variation indicated a slowed conduction velocity within the atria. This study investigated the effect of dapagliflozin on EAT volume and P-wave indices., Methods: In the present ad hoc analysis, 35 patients with type 2 diabetes mellitus and coronary artery disease were classified into dapagliflozin group (n=18) and conventional treatment group (n=17). At baseline, EAT volume, HbA1c and plasma level of tumor necrotic factor-α (TNF-α) levels, echocardiography, and 12-lead electrocardiogram (ECG) were performed. EAT volume was measured using computed tomography. Using 12-lead ECG, P-wave indices were measured., Results: At baseline, EAT volumes in the dapagliflozin and conventional treatment groups were 113±20 and 110±27 cm 3 , respectively. Not only HbA1c and plasma level of TNF-α but also echocardiography findings including left atrial dimension and P-wave indices were comparable between the two groups. After 6 months, plasma level of TNF-α as well as EAT volume significantly decreased in the dapagliflozin group only. P-wave dispersion and P-wave variation significantly decreased in the dapagliflozin group only (-9.2±8.7 vs. 5.9±19.9 ms, p=0.01; -3.5±3.5 vs. 1.7±5.9 ms, p=0.01). The change in P-wave dispersion correlated with changes in EAT volume and plasma level of TNF-α. In multivariate analysis, the change in EAT volume was an independent determinant of the change in P-wave dispersion., Conclusion: Dapagliflozin reduced plasma level of TNF-α, EAT volume, and P-wave indices, such as P-wave dispersion. The changes in P-wave indices were especially associated with changes in EAT volume.The number and date of registration: UMIN000035660, 24/Jan/2019.

A series of novel synthetic substituted benzo[d]oxazole-based derivatives ( 5a - 5v ) exerted neuroprotective effects on β-amyloid (Aβ)-induced PC12 cells as a potential approach for the treatment of Alzheimer's disease (AD). In vitro studies show that most of the synthesized compounds were potent in reducing the neurotoxicity of Aβ 25-35 -induced PC12 cells at 5 μg/mL. We found that compound 5c was non-neurotoxic at 30 μg/mL and significantly increased the viability of Aβ 25-35 -induced PC12 cells at 1.25, 2.5 and 5 μg/mL. Western blot analysis showed that compound 5c promoted the phosphorylation of Akt and glycogen synthase kinase (GSK-3β) and decreased the expression of nuclear factor-κB (NF-κB) in Aβ 25-35 -induced PC12 cells. In addition, our findings demonstrated that compound 5c protected PC12 cells from Aβ 25-35 -induced apoptosis and reduced the hyperphosphorylation of tau protein, and decreased the expression of receptor for AGE (RAGE), β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), inducible nitric oxide synthase (iNOS) and Bcl-2-associated X protein/B-cell lymphoma 2 (Bax/Bcl-2) via Akt/GSK-3β/NF-κB signaling pathway. In vivo studies suggest that compound 5c shows less toxicity than donepezil in the heart and nervous system of zebrafish.

Recent studies have correlated dysregulated miRNA expression with diseased hearts. With the aim of developing an easily manipulated experimental model, phenylephrine (PE) was added to cultured zebrafish hearts to study the expression of miR1 and miR133a by qRT-PCR. Both miRs were downregulated, with greater downregulation leading to higher hypertrophy. The involvement of this miRs was confirmed by the in-vivo inoculation of complementary sequences (AmiR1 and AmiR133a). HSP70 (involved in transporting proteins and in anti-apoptosis processes) was increased in both treatments. Hyperplasia was observed in the epicardium based on WT1 expression (embryonic epicardial cell marker) in both the PE treatment and AmiR133a treatment. The treatment with AmiR1 showed only cardiomyocyte hypertrophy. This ex-vivo model revealed that miR1 and miR133a play a key role in activating early processes leading to myocardium hypertrophy and epicardium hyperplasia and confirmed the expected similarities with hypertrophic disease that occurs in humans., Competing Interests: Declaration of competing interest 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., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The objective of this study was to evaluate the effect of chemical treatment with glutamic acid to avoid calcification of biological cardiac valves. The bovine pericardium (BP) tissues were fixed with 0.5% glutaraldehyde (BP/GA), followed by treatment with glutamic acid (BP/GA + Glu) for neutralization of the free aldehyde groups. Microscopic analysis showed that the wavy structure of collagen fibrils was preserved, but changes in elastin's integrity occurred. However, the treatment did not promote undesirable changes in the thermal and mechanical properties of the modified BPs. These samples were systematically studied in rat subcutaneous tissue: control (BP/GA) and anticalcificant (BP/GA + Glu). After 60 days, both groups induced similar inflammatory reactions. In terms of calcification, BP/GA + Glu remained more stable with a lower index (3.1 ± 0.2 μg Ca 2+ /mg dry tissue), whereas for BP/GA it was 5.7 ± 1.3 μg Ca 2+ /mg dry tissue. Bioprostheses made from BP/GA + Glu were implanted in the pulmonary position in sheep, and in vivo echocardiographic analyses revealed maintenance of valvar function after 180 days, with low gradients and minimal valve insufficiency. The explanted tissues of the BP/GA + Glu group had a lower average calcium content 3.8 ± 3.0 μg Ca 2+ /mg dry tissue. The results indicated high anticalcification efficiency of BP/GA + Glu in both subcutaneous implant in rats and in the experimental sheep model, which is an advantage that should encourage the industrial application of these materials for the manufacture of bioprostheses., (© 2020 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Toxicological effects of butylparaben (BuP) and ethylparaben (EtP) on zebrafish (Danio rerio) early-life stages are not well established. The present study evaluated, using zebrafish embryos and larvae, the toxicity of BuP and EtP through benchmark dose (BMD) approach. BuP was more toxic than EtP to zebrafish larvae. In fact, Lethal Concentration 50 (LC50) values at 96 h post-fertilization (hpf) for BuP and EtP were 2.34 mg/L and 20.86 mg/L, respectively. Indeed, BMD confidence interval (lower bound (BMDL) - upper bound (BMDU) was 0.91-1.92 mg/L for BuP and 10.8-17.4 mg/L for EtP. Zebrafish embryos exposed to 1 mg/L, 2.5 mg/L of BuP and 5 mg/L, 10 mg/L, 20 mg/L, 30 mg/L of EtP showed several developmental abnormalities and teratological effects compared to negative control. Exposed zebrafish developed reduced heartbeat, reduction in blood circulation, blood stasis, pericardial edema, deformed notochord and misshaped yolk sac. Embryos exposed to the highest concentrations of the chemicals (2.5 mg/L of BuP, 10 mg/L, 20 mg/L and 30 mg/L of EtP) showed the developmental abnormalities at 48 hpf while those treated with 1 mg/L of BuP and 10 mg/L of EtP reported behavioral changes at 72 hpf, including trembling of head, pectoral fins and spinal cord. This research identified the lethal and sublethal effects of BuP and EtP in zebrafish early-life stages and could be helpful to elucidate the developmental pathways of toxicity of parabens., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this study, the effects of doping of CQDs with alternative functional groups (dopants) were evaluated through embryonic development of zebrafish (Danio rerio). The CQDs were synthesized using simple and low-cost sources: Non-doped (citric acid was used as the carbon source), nitrogen-doped (N-doped) and nitrogen, sulfur-co-doped (N,S-doped). The CQDs induced significant toxicity to zebrafish (>150 μg/mL) and the toxic effects were dose-dependent. The N,S-doped CQDs were the most toxic (LD50 = 149.92 μg/mL), followed by the N-doped CQDs (LD50 = 399.95 μg/mL) while the non-doped CQDs were the least toxic (LD50 = 548.48 μg/mL) of the three. The growth rate (GR) was affected following the toxicity pattern (GR NS-doped N-doped non-doped blanc ), which, in turn, greatly depends on the type of dopant. Morphological malformations, such as pericardial edema, yolk sac edema, tail and spinal curvature were observed to zebrafish embryos as the toxicity, concentration and exposure time to the nanomaterial increased. Behavioral analysis showed that locomotor activity increases as the toxicity of the nanomaterial rises. The differences in toxicity, growth rate and malfunctions of CQDs were attributed to their doping with different heteroatoms. The N,S-doped CQDs, unequivocally, exhibited the most pronounced effects., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Decellularization involves removal of cellular material from tissue which results in a scaffold material consisting of only the extra cellular matrix (ECM). The effect of each individual decellularizing detergent on the final ECM scaffold and how that may differ from the combined use of these detergents is currently a gap in decellularization methodologies. This study evaluates the hypothesis that a synergistic effect exists when commonly used decellularization detergents are combined. This was evaluated with regard to decellularization efficiency, tissue strength, and collagen structure. Bovine pericardium was decellularized using a combination of 0.5% sodium dodecyl sulfate (SDS), 1% sodium deoxycholate (SDC) and 1% TritonX-100, and compared to the use of each detergent individually. The combined detergent decellularization protocol showed effective decellularization (p = .004), with minimal effects on tissue strength (p = .21) and structure (p = .21). Use of detergents individually, resulted in detrimental effects on tissue structure and integrity or ineffective decellularization. This study shows a synergistic relationship between SDS, SDC and TritonX-100 when combined at specific concentrations. The use of detergents in combination instead of individually appears to be superior, as it results in less ECM damage and improved decellularization effectivity., (© 2020 Wiley Periodicals, Inc.)

Background and Aims: The association between inflammation and atherosclerosis has been well described in the literature. There is now mounting evidence in support of adipose tissue as a reservoir for inflammatory markers. Epicardial adipose tissue (EAT) has been shown to associate with coronary atherosclerosis and found to be a predictor of future adverse cardiovascular events. This study, VIA-EAT, assesses the change in epicardial fat volume (EFV) after treatment with an investigational anti-inflammatory agent (VIA-2291) in a cohort of post-acute coronary syndrome (ACS) patients., Methods: This study is derived from a post-hoc analysis of a previously conducted randomized clinical trial (NCT00358826). Patients were recruited for a prospective, double-blind, multi-center randomized trial of a 5-lipooxygenase inhibitor or placebo in a 3:1 randomization, including doses of placebo, and 25 mg, 50 mg and 100 mg of active treatment. Cardiac computed tomography was performed at baseline and at 24 weeks after treatment with VIA-2291. EAT and pericardial adipose tissue (PAT) were measured using previously published methodology. A Pearson correlation test was used to determine the relationship between change in epicardial fat and change in plaque composition., Results: We analyzed 54 pre- and post-treatment scans. There were no major differences between traditional cardiovascular risk factors among the 4 randomized study arms. There was a significant decrease in EAT and PAT in patients in the treatment arms vs. placebo, -3.0 ± 8.2mm3 and -3.9 ± 10.9mm3 vs. 1.7 ± 7.5mm3 and 1.4 ± 10.7mm3 (p = 0.001), respectively. The changes in EAT and PAT were more pronounced in patients taking 100 mg of the drug vs. placebo: 4.2 ± 9.6mm3, -7.6 ± 8.5mm3, p = 0.0001, respectively. In a subgroup analysis, reduction in epicardial fat volume correlated with reduction in total atherosclerotic plaque volume across all VIA treatment groups, r = 0.52 (p = 0.004)., Conclusions: After adjustment for traditional cardiovascular risk factors including age, gender, body mass index, dyslipidemia and smoking, VIA-2291 decreases EAT and PAT in individuals with recent ACS. Treatment with the drug also appears to alter plaque volume and composition., Competing Interests: Declaration of competing interest Dr. Budoff received funding from Tallikut Pharmaceuticals. Dr. Almeida and Dr. Ram report no conflicts with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript., (Copyright © 2020 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Nitrate esters have been used in clinical practice for more than one century for the treatment of angina. Their clinical effectiveness is due to vasodilator activity in arteries through a method of delivering nitric oxide or a nitric oxide-like compound. Recently, an increasing numbers of functions of this molecule in biology and pathophysiology have been discovered. Macrophage polarization shift in epicardial adipose tissue (EAT) has been demonstrated to be correlated with the severity of coronary artery disease (CAD). In this study, we aimed to investigate whether nitrate esters could improve coronary atherosclerosis through inhibition of macrophage polarization shift in EAT. A case-control study enrolled 48 subjects in 2 groups: CAD patients with or without nitrate esters treatment. Infiltration of M1/M2 macrophages and the expressions of pro-inflammatory and anti-inflammatory cytokines in EAT and subcutaneous white adipose tissue were investigated by immunohistochemical stain among subjects undergoing coronary artery bypass graft surgery. The expression levels of metabolic genes were investigated by real-time reverse transcription-polymerase chain reaction (RT-PCR). We found that nitrate ester treatment significantly inhibited NF-кB activity and decreased macrophage infiltration and M1/M2 macrophage ratio in EAT in patients with CAD. The expressions of pro-inflammatory cytokines were significantly decreased, along with significantly elevated expressions of anti-inflammatory cytokines in CAD patients with nitrate ester treatment, corresponding EAT dysfunction was ameliorated and the severity of patients with CAD (Gensini score) was significantly decreased. The protective effects on macrophage polarization and EAT function through NF-кB activity inhibition suggested a potential mechanism of nitrate esters in alleviating the severity of CAD.

Major shifts in human lifestyle and dietary habits toward sedentary behavior and refined food intake triggered steep increase in the incidence of metabolic disorders including obesity and Type 2 diabetes. Patients with metabolic disease are at a high risk of cardiovascular complications ranging from microvascular dysfunction to cardiometabolic syndromes including heart failure. Despite significant advances in the standards of care for obese and diabetic patients, current therapeutic approaches are not always successful in averting the accompanying cardiovascular deterioration. There is a strong relationship between adipose inflammation seen in metabolic disorders and detrimental changes in cardiovascular structure and function. The particular importance of epicardial and perivascular adipose pools emerged as main modulators of the physiology or pathology of heart and blood vessels. Here, we review the peculiarities of these two fat depots in terms of their origin, function, and pathological changes during metabolic deterioration. We highlight the rationale for pharmacological targeting of the perivascular and epicardial adipose tissue or associated signaling pathways as potential disease modifying approaches in cardiometabolic syndromes., (© 2020 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Introduction: High beat-to-beat morphological variation (divergence) on the ventricular electrogram during programmed ventricular stimulation (PVS) is associated with increased risk of ventricular fibrillation (VF), with unclear mechanisms. We hypothesized that ventricular divergence is associated with epicardial wavebreaks during PVS, and that it predicts VF occurrence., Method and Results: Langendorff-perfused rabbit hearts (n = 10) underwent 30-min therapeutic hypothermia (TH, 30°C), followed by a 20-min treatment with rotigaptide (300 nM), a gap junction modifier. VF inducibility was tested using burst ventricular pacing at the shortest pacing cycle length achieving 1:1 ventricular capture. Pseudo-ECG (p-ECG) and epicardial activation maps were simultaneously recorded for divergence and wavebreaks analysis, respectively. A total of 112 optical and p-ECG recordings (62 at TH, 50 at TH treated with rotigaptide) were analyzed. Adding rotigaptide reduced ventricular divergence, from 0.13±0.10 at TH to 0.09±0.07 (p = 0.018). Similarly, rotigaptide reduced the number of epicardial wavebreaks, from 0.59±0.73 at TH to 0.30±0.49 (p = 0.036). VF inducibility decreased, from 48±31% at TH to 22±32% after rotigaptide infusion (p = 0.032). Linear regression models showed that ventricular divergence correlated with epicardial wavebreaks during TH (p<0.001)., Conclusion: Ventricular divergence correlated with, and might be predictive of epicardial wavebreaks during PVS at TH. Rotigaptide decreased both the ventricular divergence and epicardial wavebreaks, and reduced the probability of pacing-induced VF during TH., Competing Interests: Zealand Pharma A/S provided support in the form of salaries for author [BDL] and rotigaptide. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Objective: The aim of the study was to investigate the risk of subclinical atherosclerosis independent from obesity and high blood lipid levels in pediatric patients with idiopathic epilepsy receiving valproic acid or levetiracetam monotherapy by evaluating carotid intima-media thickness (CIMT) and Epicardial adipose tissue thickness (EATT)., Methods: A total of 75 patients (38 males, 37 females; mean age 127.2 ± 37.9 months) with epilepsy receiving either valproic acid or levetiracetam monotherapy for more than 12 months (Epilepsy Group) and 75 sex, age, body mass index (BMI) matched healthy children (40 males, 35 females; mean age 133.8 ± 38.7 months) (Control Group) were included in the study. The mean duration of therapy was 27.6 ± 10.5 months. Serum lipid levels (total cholesterol, triglycerides, low density lipoprotein, high density lipoprotein) and CIMT-EATT of the patients and controls were assessed. Also, epilepsy group were divided according to antiepileptic drugs (valproic acid group and levetiracetam group)., Results: The CIMT was determined as 0.6 ± 0.08 mm in epilepsy group and 0.49 ± 0.15 mm in control group (p < 0.001). The EATT was measured as 5.96 ± 0.8 mm in epilepsy group and 3.7 ± 0.5 mm in control group (p < 0.001). Of epileptic patients, 45 were using valproic acid monotherapy and 30 were on levetiracetam monotherapy. There was no significant difference in terms of CIMT between valproic acid and levetiracetam groups (0.61 ± 0.09 mm vs. 0.57 ± 0.07 mm; p = 0.07). EATT measurements were significantly higher in valproic acid group compared to levetiracetam group (6.14 ± 0.8 mm vs. 5.7 ± 0.7 mm; p = 0.02). CIMT and EATT values were not associated with the dosage and duration of each antiepileptic drug., Conclusion: Non-obese children with epilepsy receiving valproic acid or levetiracetam monotherapy might have an increased risk for developing subclinical atherosclerosis despite normal lipid levels. The effect of valproic acid was more evident especially on EATT., (Copyright © 2019 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

To uncover the genetic basis of anthracycline-induced cardiotoxicity (AIC), we recently established a genetic suppressor screening strategy in zebrafish. Here, we report the molecular and cellular nature of GBT0419 , a salutary modifier mutant that affects retinoid x receptor alpha a (rxraa) . We showed that endothelial, but not myocardial or epicardial, RXRA activation confers AIC protection. We then identified isotretinoin and bexarotene, two FDA-approved RXRA agonists, which exert cardioprotective effects. The therapeutic effects of these drugs only occur when administered during early, but not late, phase of AIC or as pretreatment. Mechanistically, these spatially- and temporally-predominant benefits of RXRA activation can be ascribed to repair of damaged endothelial cell-barrier via regulating tight-junction protein Zonula occludens-1. Together, our study provides the first in vivo genetic evidence supporting RXRA as the therapeutic target for AIC, and uncovers a previously unrecognized spatiotemporally-predominant mechanism that shall inform future translational efforts., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

The reconstruction of the aortic valve using glutaraldehyde-treated autologous pericardium is known as "aortic valve neo-cuspidization" (AVNeo). In-body tissue architecture (iBTA), a cell-free, in vivo tissue-engineering technology that can form autologous implantable tissues of the desired shape by subcutaneous embedding specially designed molds, was used to prepare sheet-like collagenous tissues called "Biosheets". Cylindrical molds with several line slits arranged in an alternating (n = 30) or parallel (n = 36) pattern were subcutaneously embedded in goats (n = 12) for 2 or 3 months. The tubular tissues formed in the molds were dried and then cut in the longitudinal direction, thus obtaining Biosheets (5 × 7 cm). The success rate was 97.6% when using the alternating-pattern molds and 97.2% for the parallel molds. Thickness mapping of the Biosheets showed that their entire surface, except for the line-projection portions, was smooth without any defects. The average wall thickness could be controlled over a range of ca. 0.2-0.5 mm by changing the size of the gap (0.75-1.5 mm) in the molds. The alternating slit-patterned Biosheets were found to be almost isotropic in their mechanical properties (ultimate tensile strength, fracture strain, and Young's modulus). Although the composition of the Biosheet wall was heterogeneous in terms of its density (which varied with the thickness), the breaking strength of all the alternating-patterned Biosheets increased almost linearly with the thickness within the range of the thickness of clinically used glutaraldehyde-treated pericardium as a control, and was larger than that of human aortic valve leaflets. Therefore, the alternating-patterned Biosheets have potential for use in an alternative aortic leaflet material in AVNeo., (Copyright © 2019. Published by Elsevier Ltd.)

Background and Aims: Dapagliflozin, a sodium-glucose co-transporter 2 inhibitor, improves glucose uptake by epicardial adipose tissue (EAT). However, its metabolism might raise the lactate production and acidosis under hypoxia conditions, i.e. coronary artery disease (CAD), or lipogenesis and, in consequence, expand adipose tissue. Since lactate secreted by adipose tissue is correlated with tissue stress and inflammation, our aim was to study glucose metabolism by epicardial fat in CAD and its regulation by dapagliflozin., Methods: Paired EAT and subcutaneous adipose tissue (SAT) biopsies from 49 patients who underwent open-heart surgery were cultured and split into three equal pieces, some treated with and others without dapagliflozin at 10 or 100 μM for 6 h. Anaerobic glucose metabolites were measured in supernatants of fat pads, and acidosis on adipogenesis-induced primary culture cells was analysed by colorimetric or fluorescence assays. Gene expression levels were assessed by real-time polymerase chain reaction., Results: Our results showed that dapagliflozin reduced the released lactate and acidosis in epicardial fat (p < 0.05) without changes in lipid storage-involved genes. In addition, this drug induced gene expression levels of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α), a mitochondrial biogenesis-involved gene in both EAT and SAT (p < 0.05). After splitting the population regarding the presence of CAD, we observed higher lactate production in EAT from these patients (2.46 [1.75-3.47] mM), which was reduced after treatment with dapagliflozin 100 μM (1.99 [1.08-2.99] mM, p < 0.01)., Conclusions: Dapagliflozin improved glucose metabolism without lipogenesis-involved gene regulation or lactate production, mainly in patients with CAD. These results suggest an improvement of glucose oxidation metabolism that can contribute to cardiovascular benefits., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Our understanding of reflex regulation of veins lags behind that of the arterial system. While the cardiac sympathetic afferent reflex (CSAR) exerts control over sympathetic outflow, its effect on venous tone is not known. We tested the hypothesis that activation of pericardial bradykinin sensitive afferents elicits systemic venoconstriction. Male and female Sprague Dawley rats were chronically instrumented for measurement of arterial pressure and mean circulatory filling pressure, an index of venous tone, and with an indwelling pericardial catheter. Mean arterial pressure, heart rate and mean circulatory filling pressure responses were assessed in conscious rats in response to graded pericardial injections of bradykinin (1.5-20 μg/kg) before and after ganglionic blockade, and to intravenous norepinephrine (0.05-0.8 μg/kg). Bradykinin B2 receptor was assessed by Western blot. Pericardial bradykinin injections caused graded increases in mean arterial pressure, heart rate and mean circulatory filling pressure. These responses were markedly attenuated after autonomic blockade. The increments in mean circulatory filling pressure were attenuated in female rats. There were no differences in the venoconstrictor responses to norepinephrine or ventricular bradykinin receptor expression between male and females. We interpret these findings to indicate that activation of bradykinin sensitive pericardial afferents elicits a sexually dimorphic, autonomically mediated systemic venoconstrictor response. Differences in venous smooth muscle responses to norepinephrine or ventricular bradykinin receptor expression do not account for the sexual dimorphism. We conclude that systemic venoconstriction contributes to the overall hemodynamic response to activation of the cardiac sympathetic afferent reflex and that this effect is sexually dimorphic., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In vitro human ether-à-go-go related gene (hERG) inhibition assay alone might provide insufficient information to discriminate "safe" from "dangerous" drugs. Here, effects of multichannel inhibition on cardiac electrophysiology were investigated using a family of cardiac cell models (Purkinje (P), endocardial (Endo), mid-myocardial (M) and epicardial (Epi)). We found that: (1) QT prolongation alone might not necessarily lead to early afterdepolarization (EAD) events, and it might be insufficient to predict arrhythmogenic liability; (2) the occurrence and onset of EAD events could be a candidate biomarker of drug-induced arrhythmogenicity; (3) M cells are more vulnerable to drug-induced arrhythmias, and can develop early afterdepolarization (EAD) at slower pacing rates; (4) the application of quinidine can cause EADs in all cell types, while I NaL is the major depolarizing current during the generation of drug-induced EAD in P cells, I CaL is mostly responsible in other cell types; (5) drug-induced action potential (AP) alternans with beat-to-beat variations occur at high pacing rates in P cells. These results suggested that quantitative profiling of transmural and rate-dependent properties can be essential to evaluate drug-induced arrhythmogenic risks, and may provide mechanistic insights into drug-induced arrhythmias.

Heart failure with a preserved ejection fraction (HFpEF) and heart failure with a reduced ejection fraction (HFrEF) have distinctive pathophysiologies, and thus, therapeutic approaches to the 2 disorders should differ. Neurohormonal activation drives the progression of HFrEF, and neurohormonal antagonists are highly effective in HFrEF, but not in HFpEF. Conversely, a broad range of chronic systemic inflammatory or metabolic disorders cause an expansion and inflammation of epicardial adipose tissue; the secretion of adipocytokines may lead to microvascular dysfunction and fibrosis of the underlying myocardium, which (if the left atrium is affected) may lead to atrial fibrillation (AF) and (if the left ventricle is affected) may lead to HFpEF. Anti-inflammatory drugs (such as statins and anticytokine agents) can ameliorate epicardial adipose tissue dysfunction. Statins appear to ameliorate the development of atrial myopathy (both experimentally and clinically), and in randomized controlled trials, they reduce the incidence of new-onset and recurrent AF and decrease the risk of heart failure with the features of HFpEF; yet, they have no benefits in HFrEF. Similarly, anticytokine agents appear to prevent heart failure in patients with or prone to HFpEF, but adversely affect HFrEF. Several antihyperglycemic agents also reduce epicardial fat mass and inflammation, but this benefit may be offset by additional actions to cause sodium retention and neurohormonal activation. Thiazolidinediones have favorable effects on experimental AF and HFpEF, but their antinatriuretic actions negate these benefits, and they worsen the clinical course of HFrEF. Glucagon-like peptide-1 receptor agonists also ameliorate AF and HFpEF in laboratory models, but their positive inotropic and chronotropic effects may be deleterious in HFrEF. By contrast, metformin and sodium-glucose cotransporter 2 inhibitors alleviate epicardial adipose tissue dysfunction and may reduce the risk of AF and HFpEF; yet, they may have additional actions to promote cardiomyocyte survival that are useful in HFrEF. The concordance of the benefits of anti-inflammatory and antihyperglycemic drugs on AF and HFpEF (but not on HFrEF) supports the paradigm that epicardial adipose tissue is a central pathogenetic mechanism and therapeutic target for both AF and HFpEF in patients with chronic systemic inflammatory or metabolic diseases., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose of Review: Cancer therapeutics have seen tremendous growth in the last decade and have been effective in the treatment of several cancer types. However, with advanced therapies like kinase inhibitors and immunotherapies, there have been unintended consequences of cardiotoxicities. While traditional chemotherapy and radiation-induced cardiotoxicity have been well studied, further research is needed to understand the adverse effects of newer regimens., Recent Findings: Both immune-mediated and non-immune-medicated cytotoxicity have been noted with targeted therapies such as tyrosine kinase inhibitors and immune checkpoint inhibitors. In this manuscript, we describe the pericardial syndromes associated with cancer therapies and propose management strategies. Pericardial effusion and pericarditis are common presentations in cancer patients and often difficult to diagnose. Concomitant myocarditis may also present with pericardial toxicity, especially with immunotherapies. In addition to proper history and physical, additional testing such as cardiovascular imaging and tissue histology need to be obtained as appropriate. Holding the offending oncology drug, and institution of anti-inflammatory medications, and immunosuppressants such as steroids are indicated. A high index of suspicion, use of standardized definitions, and comprehensive evaluation are needed for early identification, appropriate treatment, and better outcomes for patients with cancer treatment-associated pericardial disease. Further research is needed to understand the pathophysiology and to evaluate how the management of pericardial conditions in these patients differ from traditional management and also evaluate new therapies.

Collagen fibrils serve as the major template for mineral deposits in both biologically derived and engineered tissues. In recent years certain non-collagenous proteins have been elucidated as important players in differentially modulating intra vs. extra-fibrillar mineralization of collagen. We and others have previously shown that the expression of the collagen receptor, discoidin domain receptor 2 (DDR2) positively correlates with matrix mineralization. The objective of this study was to examine if the ectodomain (ECD) of DDR2 modulates intra versus extra-fibrillar mineralization of collagen independent of cell-signaling. For this purpose, a decellularized collagenous substrate, namely glutaraldehyde fixed porcine pericardium (GFPP) was subjected to biomimetic mineralization protocols. GFPP was incubated in modified simulated body fluid (mSBF) or polymer-induced liquid precursor (PILP) solutions in the presence of recombinant DDR2 ECD (DDR2-Fc) to mediate extra or intra-fibrillar mineralization of collagen. Thermogravimetric analysis revealed that DDR2-Fc increased mineral content in GFPP calcified in mSBF while no significant differences were observed in PILP mediated mineralization. Electron microscopy approaches were used to evaluate the quality and quantity mineral deposits. An increase in the matrix to mineral ratio, frequency of particles and size of mineral deposits was observed in the presence of DDR2-Fc in mSBF. Von Kossa staining and immunohistochemistry analysis of adjacent sections indicated that DDR2-Fc bound to both the matrix and mineral phase of GFPP. Further, DDR2-Fc was found to bind to hydroxyapatite (HAP) particles and enhance the nucleation of mineral deposits in mSBF solutions independent of collagen. Taken together, our results elucidate DDR2 ECD as a novel player in the modulation of extra-fibrillar mineralization of collagen., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The epicardium plays a crucial role in embryonic heart development and adult heart repair; however, the molecular events underlying its maturation remain unknown. Wt1 , one of the main markers of the embryonic epicardium, is essential for epicardial development and function. Here, we analyse the transcriptomic profile of epicardial-enriched cells at different stages of development and from control and epicardial-specific Wt1 knockout ( Wt1KO ) mice. Transcriptomic and cell morphology analyses of epicardial cells from epicardial-specific Wt1KO mice revealed a defect in the maturation process of the mutant epicardium, including sustained upregulation of Bmp4 expression and the inability of mutant epicardial cells to transition into a mature squamous phenotype. We identified Bmp4 as a transcriptional target of Wt1, thus providing a molecular basis for the retention of the cuboidal cell shape observed in the Wt1KO epicardium. Accordingly, inhibition of the Bmp4 signalling pathway both ex vivo and in vivo rescued the cuboidal phenotype of the mutant epicardium. Our findings indicate the importance of the cuboidal-to-squamous transition in epicardial maturation, a process regulated by Wt1., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2019. Published by The Company of Biologists Ltd.)

Blood glucose supplies energy to cells and is critical for the human brain. Glycation of collagen, the nonenzymatic formation of glucose-bridges, relates to diseases of aging populations and diabetics. This chemical reaction, together with its biomechanical effects, has been well studied employing animal models. However, the direct impact of glycation on collagen nano-structure is largely overlooked, and there is a lack of ex vivo model systems. Here, we present the impact of glucose on collagen nanostructure in a model system based on abundantly available connective tissue of farm animals. By combining ex vivo small and wide-angle X-ray scattering (SAXS/WAXS) imaging, we characterize intra- and inter-molecular parameters of collagen in decellularized bovine pericardium with picometer precision. We observe three distinct regimes according to glucose concentration. Such a study opens new avenues for inspecting the effects of diabetes mellitus on connective tissues and the influence of therapies on the resulting secondary disorders., (© 2019 The Authors. Journal of Biophotonics published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Cortisol administration during late gestation in ewes, modeling maternal stress, resulted in transcriptomic changes suggesting altered maturation and metabolic changes to the offspring heart. This study investigates the effects of cortisol on epicardial adipose tissue (EAT), a visceral fat pad associated with adverse cardiovascular conditions in adults. Pregnant ewes were treated with either 1 mg·kg -1 ·day -1 cortisol from 115 days gestation to term and EAT collected from term fetuses (control: n = 8, maternal cortisol 1 mg·kg -1 ·day -1 : n = 6). To compare the effects of cortisol to the normal maturation in EAT, we also modeled the normal changes in gene expression in EAT at the transition from in utero to postnatal life using the EAT from control fetuses and from two-week-old lambs (control: n = 7). Transcriptomic modeling was used to identify pathways altered by maternal cortisol overexposure. Transcriptomic modeling confirmed the brown fat phenotype of EAT at term and a transition toward white fat at 2 wk of age in EAT of control fetuses/lambs and highlighted a role of immune responses, including complement coagulation, and serotonin in this transition. Maternal cortisol (1 mg·kg -1 ·day -1 ) increased the lipid peroxidation product 4-hydroxynonenal in EAT of term fetuses but did not affect the number of activated macrophages or size of the lipid droplets in the depot; transcriptomics suggested an earlier metabolic maturation of EAT via, in part, increased immune responses.

Torsades de pointes is a serious side effect of many drugs that can trigger sudden cardiac death, even in patients with structurally normal hearts. Torsadogenic risk has traditionally been correlated with the blockage of a specific potassium channel and a prolonged recovery period in the electrocardiogram. However, the precise mechanisms by which single channel block translates into heart rhythm disorders remain incompletely understood. Here we establish a multiscale exposure-response simulator that converts block-concentration characteristics from single cell recordings into three-dimensional excitation profiles and electrocardiograms to rapidly assess torsadogenic risk. For the drug dofetilide, we characterize the QT interval and heart rate at different drug concentrations and identify the critical concentration at the onset of torsades de pointes: For dofetilide concentrations of 2x, 3x, and 4x, as multiples of the free plasma concentration C max  = 2.1 nM, the QT interval increased by +62.0%, +71.2%, and +82.3% compared to baseline, and the heart rate changed by -21.7%, -23.3%, and +88.3%. The last number indicates that, at the critical concentration of 4x, the heart spontaneously developed an episode of a torsades-like arrhythmia. Strikingly, this critical drug concentration is higher than the concentration estimated from early afterdepolarizations in single cells and lower than in one-dimensional cable models. Our results highlight the importance of whole heart modeling and explain, at least in part, why current regulatory paradigms often fail to accurately quantify the pro-arrhythmic potential of a drug. Our exposure-response simulator could provide a more mechanistic assessment of pro-arrhythmic risk and help establish science-based guidelines to reduce rhythm disorders, design safer drugs, and accelerate drug development., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Clinical Features: Cardiotoxicity is a rare but serious side effect of clozapine. We present a case of a psychiatric patient on chronic clozapine 75 mg daily, who presented with congestive heart failure secondary to the cardiotoxic effects of the psychiatric medication., Therapeutic Challenge: Conventional heart failure treatment failed to improve symptoms., Solution: A course of 40 mg of intravenous immunoglobulin and 125 mg of steroids was implemented, after which the patient made a full recovery. We hope to raise awareness of concurrent clozapine-induced pericarditis and myocarditis and propose a role of intravenous immunoglobulin and steroids in the treatment of drug-induced cardiomyopathy.

Propiconazole is a triazole fungicide used in agriculture. Via run-off, it can enter the aquatic environment, and can adversely affect organisms. However, data are scarce on how propiconazole may affect early developmental life stages of fish. The objectives of this study were to evaluate the potential sub-lethal effects of propiconazole during zebrafish development. Wildtype zebrafish (ABTu strain) embryos and larvae were exposed to propiconazole (0.1-100 μM) for up to 150 hours post fertilization (hpf) depending upon the endpoint measured. Propiconazole decreased survival and induced hypopigmentation in fish at 100 μM compared to the water and solvent controls. Pericardial edema was also noted in embryos and larvae (beginning at 2-3 dpf) exposed to 100 μM propiconazole. To visualize the effects of propiconazole on the circulatory system in more detail, we exposed transgenic zebrafish (globin-LCR:eGFP) to the fungicide. Hematopoietic changes were observed within 48 h of exposure to 100 μM, and localization of blood cells in the cardic region became diffuse, indicating pooling of blood in the pericardial region. We measured oxidative respiration in embryos as sufficient ATP is needed for development. Exposure to 100 μM propiconazole (~6-30 hpf) reduced basal respiration (~50%), oligomycin-induced ATP linked respiration (~70%), proton leak (~30%), and non-mitochondrial respiration (~50%), indicating compromised mitochondrial bioenergetics. A Visual Motor Response (VMR) test was used to measure dark photokinesis behavior in larval fish exposed to propiconazole for a 6-day period. Larval fish exposed to the highest concentration in the assay (10 μM) showed evidence of hypoactivity. This study demonstrates that propiconazole can induce hypopigmentation in zebrafish, disrupt mitochondrial bioenergetics, and can alter locomotor activity. However, these sub-lethal responses were observed at concentrations above what is typically detected in the environment., (Copyright © 2019 Elsevier Inc. All rights reserved.)