Cardiovascular Research (2021) 117, 2161–2174 REVIEW doi:10.1093/cvr/cvab200 Progress in cardiac research: from rebooting Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 cardiac regeneration to a complete cell atlas of the heart Sean M. Davidson 1*†, Teresa Padró 2,3†, Sveva Bollini4, Gemma Vilahur2,3, Dirk J. Duncker 5, Paul C. Evans6, Tomasz Guzik7,8, Imo E. Hoefer 9, Johannes Waltenberger 10, Johann Wojta 11, and Christian Weber 12,13 1 The Hatter Cardiovascular Institute, University College London, 67 Chenies Mews, London WC1E 6HX, UK; 2Cardiovascular Program ICCC, Institut de Recerca de l’Hospital Santa Creu i Sant Pau-IIB Sant Pau, Barcelona, Spain; 3CIBER Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III (ISCIII), Madrid, Spain; 4Department of Experimental Medicine (DIMES), University of Genova, Genova, Italy; 5Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus University Medical Center, Rotterdam, The Netherlands; 6Department of Infection, Immunity and Cardiovascular Disease and Insigneo Institute, University of Sheffield, Sheffield, UK; 7British Heart Foundation Centre for Cardiovascular Research, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK; 8Department of Medicine, Jagiellonian University, Collegium Medicum, Krakow, Poland; 9Central Diagnostic Laboratory, University Medical Center Utrecht, Utrecht, The Netherlands; 10Department of Cardiovascular Medicine, Medical Faculty, University of Muenster, Muenster, Germany; 11Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria; 12Institute for Cardiovascular Prevention (IPEK), LMU Munich, DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, and Munich Cluster for Systems Neurology (SyNergy), Munich, Germany; 13Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands Received 23 March 2021; revised 10 May 2021; editorial decision 4 June 2021; accepted 10 June 2021; online publish-ahead-of-print 11 June 2021 This paper was handled by consulting editor Elizabeth Murphy. Abstract We review some of the important discoveries and advances made in basic and translational cardiac research in 2020. For example, in the field of myocardial infarction (MI), new aspects of autophagy and the importance of eosi- nophils were described. Novel approaches, such as a glycocalyx mimetic, were used to improve cardiac recovery following MI. The strategy of 3D bio-printing was shown to allow the fabrication of a chambered cardiac organoid. The benefit of combining tissue engineering with paracrine therapy to heal injured myocardium is discussed. We highlight the importance of cell-to-cell communication, in particular, the relevance of extracellular vesicles, such as exosomes, which transport proteins, lipids, non-coding RNAs, and mRNAs and actively contribute to angiogenesis and myocardial regeneration. In this rapidly growing field, new strategies were developed to stimulate the release of reparative exosomes in ischaemic myocardium. Single-cell sequencing technology is causing a revolution in the study of transcriptional expression at cellular resolution, revealing unanticipated heterogeneity within cardiomyo- cytes, pericytes and fibroblasts, and revealing a unique subpopulation of cardiac fibroblasts. Several studies demon- strated that exosome- and non-coding RNA-mediated approaches can enhance human induced pluripotent stem cell (iPSC) viability and differentiation into mature cardiomyocytes. Important details of the mitochondrial Ca2þ uni- porter and its relevance were elucidated. Novel aspects of cancer therapeutic-induced cardiotoxicity were de- scribed, such as the novel circular RNA circITCH, which may lead to novel treatments. Finally, we provide some insights into the effects of SARS-CoV-2 on the heart. † The first two authors contributed equally to the study. * Corresponding author. Tel: þ44 2034479894, E-mail: s.davidson@ucl.ac.uk C The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology. V This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. 2162 S.M. Davidson et al. Graphical Abstract Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 ................................................................................................................................................................... Keywords Cardiac • Myocardial infarction • Myocardial injury • Heart failure • Non-coding RNA • Cardiomyocyte division • Induce pluripotent stem cells • Cardiotoxicity • Single-cell RNA sequencing s • COVID-19 1. Introduction The year 2020 was unique in modern history, temporarily affecting normal research activities worldwide, as well as affecting much of normal life. Nevertheless, cardiovascular research continued unabated, and output even increased. Incredibly, the number of publications in PubMed containing the keyword ‘cardiac’ actually increased by 14%, from 86 498 in 2019 to 98 683 in 2020. Here, we highlight some of the major advan- ces that were made in basic and translational cardiac research—and mechanistic studies that we believe may have the greatest impact on the development of future therapeutics and bio-analytics for cardiovascular disease (Figure 1). It is, by its nature, a subjective selection, and some important advances may have been overlooked, but it represents a snapshot of some of what the authors believe were research highlights in 2020. 2. Myocardial infarction, ischaemia/ reperfusion injury, and heart failure, Figure 1 The top cardiac-related phrases appearing in the titles of a trilogy Cardiovascular Research articles published in 2020, with the size of the font indicating the phrase’s frequency. Ischemia and reperfusion (IR) injury is an unavoidable deleterious effect that determines the final infarct size after successful revascularization following myocardial infarction (MI). There is currently no effective .. therapy for reducing cardiac damage in the setting of MI. The year 2020 .. in cardiac-restricted TXNIP-knock out mice with experiments in has brought relevant data to improve our understanding of the patho- .. primary cultures of cardiomyocytes, the authors demonstrated that .. physiological mechanisms behind IR and has identified new potential .. TXNIP (a pro-oxidative molecule) inhibits autophagosome clearance therapeutic targets to limit infarct size and the consequent adverse .. via a reactive oxygen species (ROS)-mediated mechanism; however, it .. cardiac remodelling. .. upregulates autophagosome formation by upregulating Redd1 (mTOR Gao et al.1 propose a novel signalling pathway, TXNIP (thioredoxin- .. inhibitor), leading to exacerbated autophagy after reperfusion and .. interacting protein)/Redd that contributes to IR injury by promoting ex- .. consequent cardiomyocyte death.1 The study by Liu et al.2 sheds new cessive autophagy during reperfusion. In particular, by combining studies .. light on the role of eosinophils in acute MI. Through a series of Cardiac research in 2020 2163 .. mechanistic studies and transgenic mice, the authors provide evidence .. oxygenase-1) expression and reduction in ROS production, overall sup- that eosinophils, by producing IL-4 and cationic protein mEar1, mitigate .. porting the use of PPIs to alleviate cardiac adverse remodelling.8 .. cardiomyocyte death, fibroblast activation, and neutrophil adhesion, ulti- .. One crucial outstanding question is why it has not yet been possible mately improving cardiac function. The work establishes a cardioprotec- .. to translate cardioprotection to the clinic. This question was addressed .. tive role of eosinophils against post-IR injury supporting the hypothesis .. in a position paper of the Working Group on Cellular Biology of the that an increase of circulating and cardiac eosinophils represents a com- .. Heart, which provides important recommendations to improve transla- .. .. tional research in sex-specific effects of comorbidities and risk factors in Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 pensatory mechanism to repair the ischemic heart. Regarding novel approaches and opportunities for cardioprotection, .. ischaemic heart disease.9 Furthermore, Schreckenberg et al. proposed .. the Panitch lab proposed a new therapeutic approach to limit IR injury .. that there may be a mix of responders and non-responders to cardio- by interfering with leukocyte recruitment and attachment at the site of .. protective interventions, and they identified the mitochondrial transcrip- .. injury.3 The authors designed a novel selectin-targeting glycocalyx mi- .. tome as potentially involved.10 .. metic (named DL-IkL) that targets a glycocalyx component of the dam- .. aged endothelium and reduces the availability of endothelial adhesion .. .. 3. Rebooting cardiac regeneration molecules (mainly selectins) interfering with neutrophil binding to the in- .. .. flamed vessel wall. Administration of this new compound at reperfusion .. by cardiomyocyte renewal and and 24 h thereafter to mice with a MI reduced neutrophil and macro- .. phage accumulation, tissue fibrosis and cardiac damage, and improved .. tissue engineering strategies .. cardiac function.3 Other novel therapeutic approaches to limit cardiac .. Since the first report in 2011, describing transient mammalian neonatal damage and lessen adverse cardiac remodelling have also been pro- .. .. heart myocardial renewal by means of resident cardiomyocyte de- posed. By means of cardiac magnetic imaging analyses in a pig model of .. differentiation and proliferation,11 several independent studies have .. MI, Mendieta et al.4 demonstrated that administration of intravenous .. addressed the role of genetic, metabolic, immunologic, and stimulatory atorvastatin during ischemia limits cardiac damage, improves the recov- .. environmental factors to restore endogenous regenerative response in .. ery of systolic function and mitigates adverse cardiac remodelling to a .. the heart. Therefore, the comprehensive analysis of regulatory mecha- larger extent than when administered orally shortly after reperfusion. .. .. nisms of cardiomyocyte cell-cycle control has become of increasing in- Furthermore, this intravenous approach also limits the systemic inflam- .. terest to basic and translational cardiac researchers (Figure 2). matory response. This highly translational study supports the concept .. .. Several studies published in 2020 offered significant new insights into that statins can be repurposed and used intravenously as a feasible and .. the mechanism of myocardial regeneration via reactivation of cardio- safety cardioprotective approach on first medical contact in the setting .. .. myocyte division. Volland et al.12 translated insights from cardiac devel- of STEMI.4 Another study that deserves to be highlighted in the field of .. opment by demonstrating that BRCA1-associated protein (BRAP) is IR focused on the effect of circadian rhythm on acute MI, a subject of .. .. pivotal in blocking the cell-cycle inhibitor p21Cip, thus allowing DNA syn- considerable scientific interest but with a wide knowledge gap with re- .. thesis, cell-cycle progression, and proliferation in murine cardiomyo- .. spect to the mechanism of the interaction. Zhang’s group demonstrated, .. cytes.12 In particular, the authors revealed a specific role for BRAP in in cardiomyocyte-specific Krüppel-like factor 15 (KLFL15) knockout .. regulating cardiac development and cardiomyocyte cell-cycle control; .. mice, the key contribution of this oscillatory transcription factor to the .. BRAP ablation resulted in attenuation of neonatal cardiomyocyte cell- susceptibility of IR injury in a time-of-day specific manner.5 Moreover, .. cycle progression and evoked lethal heart failure in vivo at post-natal age; .. the effects of KLF15 were linked to the presence of NADþ, a key co- .. conversely, its overexpression enhanced the engagement into the DNA .. enzyme for the proper functioning of mitochondrial deacetylase sirtuin- .. duplication phase and reduced p21Cip expression in neonatal cardiomyo- 3.5 The authors suggest that NADþ supplementation during a critical .. cytes. Therefore, BRAP signalling appears to be critical to regulate cardi- time window may be particularly beneficial for patients with chronic .. .. omyocyte cell-cycle machinery, myocardial development, and adult heart diseases. .. myocardial performance, hence suggesting a fine mechanism with critical .. Over the past few years, long non-coding RNA (lncRNAs) have .. impact for future regenerative strategies. emerged as key regulators of the biological processes involved in the .. The recapitulation of the embryonic developmental programme— .. progression of heart failure.6 Viereck et al.7 focused on the potential of .. such as activation of epithelial–mesenchymal transition (EMT) in cardiac the highly conserved lncRNA H19, found to be downregulated in failing .. stromal cells—has previously been shown to trigger reparative mecha- .. hearts. The authors demonstrated that cardiomyocyte-directed H19 .. nisms within the heart.13,14 In 2020, Aharonov et al.15 showed that tran- gene therapy suppresses pressure-overload-induced left ventricular car- .. sient overexpression of activated ERBB2 in adult cardiomyocytes caused .. diac failure at both structural and functional level in mice. .. cardiac regeneration in a preclinical murine model of heart failure. Mechanistically, the Thum lab identified a link between H19 and the sup- .. Restoration of ERBB2 signalling in the injured myocardium triggered an .. pression of pro-hypertrophic NFAT (nuclear factor of activated T cells) .. EMT-like response within resident cardiomyocytes defined by cytoskele- signalling.7 These findings open up new pathways for exploiting H19 as a .. .. tal remodelling, junction dissolution, and extracellular matrix turnover, potential therapeutic target in the management of heart failure patients.7 .. overall inducing their migration and replacement of scar tissue by means .. Lin et al.8 provided novel insights into the controversial approach of .. of myocardial renewal. This study suggests that reactivation in adult car- using proton pump inhibitors (PPIs) beyond their acid-suppressing ac- .. diomyocytes of developmental EMT-like behaviour and ERBB2–ERK– .. tion. In this work, the authors demonstrate that lansoprazole administra- .. YAP mechano-transduction signalling may represent a relevant thera- tion attenuates pressure overload-induced cardiac hypertrophy and .. peutic target for cardiac restoration following injury. .. improves heart failure in mice regardless of its Hþ/Kþ-ATPase inhibition. .. Besides analytical investigation of signalling pathways regulating cardio- The protective benefits were associated with inhibition of the AKT/ .. myocyte cell-cycle activity, increasing interest has been directed towards .. GSK-3b/b-catenin signalling pathway, upregulation of HO-1 (heme . non-cardiomyocyte cell types, in driving myocardial renewal. Wu et al.16 2164 S.M. Davidson et al. Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 Figure 2 Schematic of the latest insights on myocardial renewal and tissue engineering strategies to enhance cardiac repair and to stimulate heart re- generation following injury. BRAP, BRCA1-associated protein; EMT, epithelial–mesenchymal transition; ECM, extra-cellular matrix; NPNT, nephronectin; RELN, Reelin; hiPSC, human induced pluripotent stem cell. Schematic has been produced using Smart—Servier Medical Art (available at https://smart.serv ier.com). .. recently addressed the role of post-natal cardiac fibroblasts and ex- .. cardiomyocytes.21–23 Notably, Li et al.24 confirmed that macrophage re- tra-cellular matrix (ECM) in influencing cardiomyocyte cell division .. cruitment is critical to initiating endogenous myocardial regeneration, .. by showing that fibroblast-induced ECM modulation can affect cardi- .. since genetic ablation of murine CD11b-positive macrophages inhibited omyocyte cytokinesis and induce their binucleation. SLIT2 and .. neonatal heart restoration with worsening of cardiac function after .. Nephronectin (NPNT) were identified as fibroblast-derived ECM .. apical resection. Moreover, the fundamental function of macrophages in reference components exerting proliferative effects, thus revealing .. myocardial renewal was validated by evidence of restoration of cardio- .. two putative molecular candidates for further investigation on the .. myocyte proliferation following transplantation of neonatal cardiac .. mechanisms underlying bona fide cardiomyocyte cytokinesis from .. macrophages in the injured adult heart.24 embryonic to adult stages. .. At present, preclinical heart research in mammals focuses mainly on .. Recent data have emphasized the role of lymphatic cells in improving .. left ventricle myocardial infarction or cardiac ischaemic- or cardiotoxic cardiac function and inhibiting detrimental remodelling after injury.17–19 .. injury models with the aim of modelling the adult clinical scenario. There .. Liu et al.20 recently identified a function for lymphatic endothelial cells .. is often limited correlation with congenital heart disease affecting paedi- (LECs) in orchestrating cardiomyocyte proliferation and survival during .. atric patients. Of note, tetralogy of Fallot, pulmonary artery hyperten- .. heart development including the early post-natal regenerative stage. .. sion, and pulmonary stenosis in children are often caused by pressure LECs were shown to release trophic lympho-angiocrine signals, among .. overload in the right ventricle.25,26 Against this background, Ye et al.27 re- .. which the extracellular protein Reelin (RELN) emerged as promising .. cently showed in the rat, that pulmonary artery banding at post-natal day .. therapeutic candidate, since it improved myocardial rescue in the adult .. 1 induces right ventricle pressure overload. This triggers myocardial re- mouse heart when administered via a bioengineered collagen patch.20 A .. newal activation by over-proliferation of resident neonatal cardiomyo- .. growing body of evidence on the role of immune system cells during car- .. cytes. Interestingly, such findings were further verified by histological diac repair indicates that macrophages are prominent facilitators of neo- .. analysis of human specimens of tetralogy of Fallot. The results suggest, .. natal mouse heart regeneration and cardiomyocyte mitochondrial .. for the first time, that right ventricular pressure overload model may homeostasis, e.g. by eliminating dysfunctional mitochondria ejected by .. represent an additional relevant model of heart regeneration and Cardiac research in 2020 2165 .. neonatal cardiomyocyte proliferation, with translational relevance for .. (17.5%), revealed a remarkable interferon response in many cell types of the pathogenesis of many paediatric congenital heart diseases. .. the diseased heart, which indicates a therapeutic target.33 By offering a .. New cardiac tissue engineering strategies were developed in 2020, in .. new lens with which to view the heart, single-cell transcriptomics is sure order to provide reliable tissue models for translational research (Figure .. to lead to many future insights into the secret life of cells of the heart. .. 2). For example, Kupfer et al.28 optimized a 3D bio-printing strategy .. A cell type of particular interest is macrophages, which are not only in- based on an ECM-derived bio-ink formulation, which supported human .. tegral to the initial inflammatory response to injury, but also to subse- .. induced pluripotent stem cell (iPSC) viability, proliferation, and matura- .. Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 quent wound healing. Consequently, maladaptive immune cell behaviour tion into cardiomyocytes. This technique resulted in the fabrication of a .. .. contributes to ventricular remodelling. A paradigm shift in macrophage geometrically complex, chambered cardiac organoid with robust elec- .. biology occurred with the recognition that they can be divided into a tromechanical function, and provided remarkable advances in terms of in .. .. population of pro-inflammatory, M1 macrophages and a population of situ pluripotent stem cell differentiation at high density.28 Such engi- .. reparative, M2 macrophages. Initial investigations of cardiac macrophage neered human cardiac structures could be exploited as drug screening .. .. populations following acute MI suggested they aligned well to this model. platforms or for use in experimental medicine with in vitro developmental .. However, as reviewed by Peet et al., 34 more recent data demonstrate or injury/disease models. From a regenerative point of view, an acellular .. .. remarkable heterogeneity and plasticity in macrophage development, artificial cardiac patch has recently been described with cardioprotective, .. pro-angiogenic and proliferative potential in rodent and porcine models .. phenotype, and function (Figure 3). These recent insights into macro- .. phage biology may explain the failure of non-specific immunosuppressive of acute myocardial infarction.29 De-cellularized porcine myocardium .. .. strategies and are important to understand in the development of novel was engineered with biodegradable polylactic-co-glycolic acid (PLGA) .. .. therapies targeting heart failure following acute MI.34 microcarriers delivering human cardiac stromal cell-secreted factors.29 .. While a robust inflammatory response to tissue injury is a necessary This combinatorial approach resulted in the optimization of a ready-to- .. part of the repair process, it can also result in the deposition of scar tis- use and cell-free graft, which maintained regenerative properties after .. .. sue. Bevan et al.35 used stable transgenic lines, whole organ imaging and cryopreservation, thus suggesting a feasible and clinically compliant ther- .. apeutic strategy.29 As such, this study offers an elegant proof-of-principle .. genetic and pharmacological interventions to demonstrate that different .. subsets of macrophages promote scar deposition following cardiac injury for the functional association of tissue engineering technique with para- .. crine therapy to heal the injured myocardium. .. and facilitate scar removal during regeneration.35 Osteopontin was iden- .. tified as having both pro-fibrotic but also potentially pro-regenerative .. .. roles in the adult zebrafish heart, driving collagen deposition but also .. 4. Looking beyond the .. controlling inflammatory cell resolution.35 .. The use of stem cell therapy as a means to regenerate the heart has a cardiomyocytes—from phenotyping .. .. long and chequered history. Despite the intuitive attractiveness of the individual cell types to cell atlases of .. .. approach, few still believe that it results in significant cardiac regenera- the heart .. tion. While intracardiac stem cell injection appears to slightly improve .. cardiac function following MI, no clear mechanism had been established .. Microscopy entered a new era with the development of super- .. until Vagnozzi et al.36 showed it acts through an acute sterile immune re- resolution techniques. Similarly, single-cell transcriptomics has kicked off .. .. sponse. This was characterized by the temporal and regional induction a revolution in genetics, by providing a high-resolution view of gene tran- .. of CCR2(þ) and CX3CR1(þ) macrophages. Remarkably, the same re- scription at the level of individual cells, rather than bulk tissue. Next- .. .. sponse could be obtained by injecting either killed cells or a chemical in- generation sequencing of mRNA expression in individual cells, combined .. ducer of the innate immune response. By modulating the macrophage with machine learning, can now provide unprecedented, granular detail .. .. response, these treatments initiated an acute, inflammation-based, of the individual cell types present within tissues.30 The trajectories of in- .. wound-healing response that rejuvenates the infarct area of the heart. dividual cell types can be followed as they undergo differentiation. In .. .. This important study likely represents a capstone on 30 years of research 2020, the technique’s enormous potential for the field of cardiovascular .. biology was revealed by a landmark study, published in Nature, which .. investigating the mechanism of stem cell-mediated regeneration of the .. injured heart. attempted to identify and categorize all the cell types of the adult human .. heart.31 After analysing approximately half a million single cells, this inves- .. In a further example of the importance of inter-cellular communica- .. tion, Zhao et al.37 used an impressive variety of techniques ranging from tigation revealed a surprising diversity of cell types in the heart, and unan- .. .. bone marrow transplantation and parabiosis (conjoining of circulatory ticipated heterogeneity within cardiomyocytes, pericytes, and .. fibroblasts.31 Functional interactions between different cell types such as .. systems) to show that mir-210 can be delivered to the endothelium .. through the blood by a long-range endocrine mechanism. Significantly, it immune cells and fibroblasts could be deduced.31 By applying this same .. approach to mouse hearts, Ruiz-Villalba et al.32 were able to identify a .. modulated expression of target genes in the endothelium and promoted .. pulmonary hypertension. unique subpopulation of cardiac fibroblasts expressing high levels of .. CTHRC1 (collagen triple helix repeat containing 1), that emerges fol- .. The cancer field has recently undergone a revolution with the discov- .. ery that cytotoxic T cells can be redirected to specifically recognize and lowing myocardial infarction and reduces the likelihood of death due to .. cardiac rupture. Suryawanshi et al.33 used single-cell transcriptomics to .. eliminate cancer cells. Aghajanian et al.38 were able to ‘repurpose’ this .. produce an equivalent map of all the cells within the foetal human heart. .. technique, using T cells to recognize a novel cardiac fibroblast epitope This showed an unanticipated diversity of cardiac cell types and allowed .. they identified. By eliminating cardiac fibroblasts from injured mouse .. the separation of endothelial cells into previously uncharacterized sub- .. hearts it was possible to restore cardiac function. These results provide populations. A comparison with foetal human hearts affected by congen- .. proof-of-principle for the development of immunotherapeutic drugs for .. ital heart block (CHB), a disease that results in significant mortality . the treatment of cardiac disease. 2166 S.M. Davidson et al. Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 Figure 3 (A) Identification of cell types in human foetal heart. Clustering for 12 461 cells from three healthy samples based on established lineage markers and visualized using t-SNE. (B) Averaged proportion of all cell types (except EBs) contributing to foetal human hearts. Middle panel indicates major cell groups with subgroups of immune cells (top panel) and endothelial cells (bottom panel) and number in parenthesis indicates percentage contribution to foe- tal heart cells. Figure taken from Suryawanshi et al.33 with permission. (C) Novel macrophage populations appear to play spatially restricted roles in remodel- ling of the myocardium following acute myocardial injury (AMI). Novel high throughput techniques allow unbiased resolution of cells into distinct populations, based on gene expression profile (scRNA-seq) or large panels of differentially expressed proteins (mass cytometry). Figure taken from Peet et al.34 with permission. Cardiac research in 2020 2167 .. 5. Cell-to-cell communication via .. .. exosome-miR1956-VEGF signalling in AD-MSCs. The benefits of exosome-induced paracrine signalling on cardiac regeneration were also exosomes and non-coding RNA .. .. evidenced in human iPSCs derived from cardiac fibroblasts (CF-iPSC).42 .. CF-iPSC exosomes were enriched in miRNA cluster miR-371-373, Cell-to-cell communication plays a pivotal role in cardiac remodelling .. and function, both under physiological conditions to maintain myocardial .. highly expressed in human embryonic stem cells, and significantly en- .. hanced spontaneous differentiation of CF-iPSC into cardiomyocytes, evi- homeostasis, and under pathological conditions as an adaptive response .. .. denced by the increased number of contracting embryoid bodies. Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 to injury and stress. In 2020, different studies aimed at gaining a better .. .. There is consistent evidence that the molecular cargo of exosomes understanding of how crosstalk between cells affects cardiac function, resulted in the identification of novel pathophysiological mechanisms of .. varies depending on environmental stimuli. Accordingly, there is increas- .. ing interest in identifying strategies to modulate endogenous exosome intercellular communication. .. .. composition and thereby influence their biological effects. Lew et al.43 Moreira et al.39 identified a novel calcitonin-mediated paracrine mech- .. .. performed a study in diabetic db/db mice, in which the effectiveness of anism between cardiomyocytes and fibroblasts in the human atrial myo- cardium that tightly regulates fibroblast function, preventing the .. exercise for preventing or reversing cardiac and coronary dysfunction in .. diabetes was highlighted. Importantly, the study provided novel evidence accumulation of fibrous tissue and fibrogenesis. The authors used human .. .. implicating cardiovascular-related miRNAs and particularly miR-126 and right atrial tissue to demonstrate that isolated cardiomyocytes abun- .. its molecular targets (SPRED1/VEGF) as mechanistic effectors underlying dantly express the thyroid hormone calcitonin. Through specific .. .. the vascular protective ability and cardioprotective properties of exer- receptor-binding on the membrane of atrial fibroblasts, cardiomyocyte- .. cise training. Of note, exercise-mediated changes in miRNA translation released calcitonin acts as a paracrine signal controlling cell proliferation .. .. were related to the intensity and the time at which exercise was imple- and BMP1 (bone morphogenetic protein-type 1)-related collagen proc- .. mented during disease progression (i.e. early vs. late) in the diabetic essing, as demonstrated by single-cell RNA sequencing and proteomic .. .. mice. approaches. Supporting this finding, patients with persistent atrial fibrilla- .. .. Recent evidence also points to rare subtypes of non-coding RNAs, tion, a highly prevalent cardiac arrhythmia associated with considerable .. such as circular RNAs (circRNAs), as novel contributors to cardiovascu- mortality and morbidity, had impaired production of myocardial calcito- .. nin with loss of calcitonin receptor in the fibroblast membrane. Using .. lar pathophysiology. However, their functional role in cardiac remodel- .. ling in different pathological settings still requires better delineation. Li et several different mouse models, either with global disruption of calcito- .. .. al.44 showed that circRNA_000203 was upregulated in the myocardium nin receptor expression or with atrial-specific knockdown of calcitonin, .. of Angiotensin-II (AngII)-infused mice to induce cardiac hypertrophy, and Moreira et al.39 demonstrated the relevance of the calcitonin–calcitonin .. .. identified the potential mechanism involved. By means of dual luciferase receptor axis to control susceptibility to atrial fibrosis and fibrillation. .. and RNA-pull-down assays, authors demonstrated that Evidence that has been accumulated over the past years relates the .. .. circRNA_000203 acted as a sponge for miR-26b-5p and miR-140-3p in cardioprotective effects of mesenchymal stromal cells (MSC) to their .. cardiomyocytes, which resulted in the increased expression of their paracrine activities, which result in anti-apoptotic, pro-angiogenic and .. .. common target gene, GATA4, thereby contributing to aggravated car- immunomodulatory mechanisms rather than de novo cardiomyocyte re- .. diac hypertrophy. generation through replication and differentiation. Using mouse models .. .. Beyond lipid-lowering, statins exert cardioprotective effects (see of MI and myocardial I/R, Yan et al.40 demonstrated that N-cadherin .. Mendieta et al.4). In this respect, Huang et al.45 demonstrated that exo- overexpression prolongs myocardial retention of implanted adipose- .. .. somes released from atorvastatin-pretreated MSCs increased survival derived stem cells (ADSC) and enhances ADSC cardioprotective effects, .. and promoted cell migration and tube-like structure formation when de- mainly preserving capillary density and cardiomyocyte proliferation. .. .. livered into endothelial cells in vitro, under hypoxia and serum depriva- Furthermore, the authors highlighted an increase in N-cadherin/b-cate- .. tion conditions. In addition, atorvastatin pre-treatment promoted the .. nin interaction and intracellular trafficking of b-catenin, with the subse- .. efficiency of MSC-derived exosomes to preserve cardiac function and quent expression of downstream molecules such as metalloproteinase .. enhance angiogenesis in animals presenting acute MI. Using different .. (MMP)-10 and MMP-13 and hepatocyte growth factor (HGF), as respon- .. mechanistic approaches, the authors identified lncRNA H19 as a media- sible for the enhanced cardioprotective effects derived from N-cadherin .. .. tor of the pro-angiogenic effects induced by the atorvastatin-pretreated overexpression in ADSC. .. MSCs. Exosomes are extracellular nanovesicles, released by a wide spectrum .. .. In recent years, increasing interest has been directed towards stimu- of cell types and carrying non-random subsets of bioactive molecules .. lating the specific release of reparative exosomes in the ischemic myo- (proteins, lipids, non-coding RNAs and mRNAs) already present in their .. .. cardium. Shock wave therapy (SWT) is frequently used as adjuvant cells of origin. Together with soluble factors, exosomes are increasingly .. therapy to improve wound healing, and a first-in-human study in patients .. recognized as active intercellular messengers in paracrine signalling, but .. with acute myocardial infarction was recently reported, 46 although the mechanisms involved and their role as potential novel therapeutic .. mechanisms involved were not identified. The study by Gollmann- .. candidates to improve heart function remain unclear. Gao et al.41 dem- .. Tepeköylü et al.47 evidenced an increased release of miRNA-19a-3p onstrated, in a mouse model of MI that post-MI circulating exosomes .. enriched endothelial-exosomes in response to SWT, both in vitro and .. from heart and kidney origin mediate the activation of pro-angiogenic .. in vivo. Of note, exosomes derived from SWT-stimulated cells induced signalling in adipose-derived MSCs (AD-MSCs). Through mechanistic .. VEGF-mediated angiogenic signals and capillary formation. Using a .. studies in cultured AD-MSCs, the authors linked the effects of cardio- .. mouse model of MI, the authors demonstrated the beneficial effects on renal serum exosomes with activation of vascular endothelial growth .. cardiac contractility after treatment with the exosomes released from .. factor (VEGF) signalling after delivering miR-1956 into the cells. Thus, .. SWT-stimulated cells. miR-1956 acted as a functional exosome-messenger by downregulating .. Strategies to enhance exosome effectiveness as a therapeutic tool .. Notch-1 expression, which was identified as a key mediator of . also consider manipulating endogenous exosome biodistribution to 2168 S.M. Davidson et al. .. increase their local concentration in response to need. In this regard, Liu .. integration of implanted cells. However, Lou et al.54 showed that cell en- et al.48 designed antibody-conjugated magnetic nanoparticles that can be .. graftment could be improved by overexpressing N-cadherin, a protein .. used as a vesicle shuttle, due to their ability to simultaneously capture .. that mediates the adhesion between cardiac myocytes (CMs). This also circulating exosomes (CD63-antigen binding) and target injured cardio- .. improved their functional integration via paracrine activation of the ex- .. myocytes (myosin-light chain antigen) in the infarcted area, in addition to .. tracellular signal-regulated kinase (ERK) signal transduction pathway, in- facilitating the local release of the captured exosomes on the injured car- .. ducing neo-vasculogenesis and increasing survival of the implanted cells. .. diac tissue. The applicability of this novel vesicle-shuttle approach as a .. Importantly, in mice that received these cells following MI, infarct size Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 strategy for therapy was demonstrated in rat and rabbit models of MI. .. was also reduced and left ventricular (LV) ejection fraction was .. Thus, magnetic-guided accumulation of exosomes in infarcted tissue led .. improved.54 to a reduction in the infarct size and enhanced angiogenesis four weeks .. Another interesting protein, very important in angiogenesis and cellu- .. after treatment, in addition to an improvement of the cardiac function, .. lar interactions, is angiopoietin-1. When Tao et al.55 overexpressed this as assessed by echocardiography. .. protein in human atrial human iPSC-CMs, and seeded them into a fibrin/ .. .. thrombin patch that was then implanted on the rat hearts following MI, .. the implanted cells secreted Ang-1 protein for up to 14 days, upregu- .. 6. iPSC-CM (in vitro contraction, .. lated ERK signalling and inhibited pro-apoptotic Bax protein expression. .. arrhythmia, in vivo cardiac repair) .. .. They saw increased mitosis and arteriole formation, improved cell en- graftment rate, and less LV dilation and improved LV global pump As can be seen from the previous section, there is still a great deal that .. function. .. remains to be understood about how exosomes function. One resource .. Thus, while some studies suggest that iPSC-CM may be able to re- that will be useful for investigating this is the atlas of exosomal .. store the damaged heart, other studies suggest that additional .. microRNAs from human iPSC-derived cardiac cells, created by Chandy .. approaches such as those mediated through paracrine mechanisms may .. et al.49 To create this database, human iPSC were differentiated into car- .. be required to provide meaningful benefit. diomyocytes (iPSC-CMs), endothelial cells (iPSC-ECs), or cardiac fibro- .. .. blasts (iPSC-CFs). Small extracellular vesicles (sEVs) were then isolated .. from them using a microfluidic system, and their miRNA contents was .. .. 7. Powering the heart— sequenced and compared to the source cell. Interestingly, only a subset .. mitochondria and metabolism of total cellular miRNAs was found to be secreted in sEVs, but a com- .. .. mon core of miRNAs was secreted by all three cardiac cell types. There .. Transport of Ca2þ into mitochondria is mediated by the mitochondrial was some cell specificity. For example, miR-1, which is critical for cardiac .. Ca2þ uniporter (MCU). This is important for metabolic adaption to .. development and pathology, was only secreted by iPSC-CMs. .. work, but since it exposes the mitochondria to the risk of Ca2þ over- A practical way to study inherited arrhythmias in vitro without the .. load, MCU activity is modulated by other proteins. One such protein is .. need for cardiac biopsies is to differentiate patient-derived iPSCs into .. the MCUB subunit. Using mice with cardiomyocyte-specific overexpres- cardiomyocytes. Benzoni et al.50 took advantage of this technique to in- .. sion or deletion of MCUB, Huo et al.56 showed that MCUB is inducible .. vestigate the mechanism of inherited, untreatable persistent atrial fibrilla- .. and limits mitochondrial Ca2þ influx after IR, preventing mitochondrial tion. Electrophysiological characterization of the patient-derived .. permeability transition pore (mPTP) opening and protecting the myocar- .. cardiomyocytes revealed functional alterations of If and ICaL currents .. dium. Interestingly, hindlimb remote ischemic preconditioning increased leading to a cardiac substrate more prone to develop arrhythmias under .. MCUB expression in the heart and decreased mitochondrial Ca2þ .. stressful conditions. .. uptake. One limitation of using iPSC-CM for electrophysiological or other .. Another regulator of MCU activity that plays an important role in reg- .. studies, is that the iPSC-derived cells more closely resemble foetal cardi- .. ulating pathological Ca2þ overload in the heart is MICU3 (mitochondrial omyocytes, utilizing glycolysis for ATP generation, and expressing imma- .. calcium uptake 3). Puente et al.57 eliminated MICU3 globally utilizing .. ture ion channels (e.g. high levels of the ‘sinoatrial’ (If) current, and low .. CRISPR-Cas9 and found that the mice were protected against IR injury levels of IK1, which leads them to beat spontaneously).51 Therefore, .. and isoproterenol-induced cardiac dysfunction. Interestingly, it was origi- .. Garbern et al.’s52 discovery that inhibition of mTOR signalling enhances .. nally found that global ablation of MCU is not cardioprotective,58 al- .. maturation of cardiomyocytes derived from human iPSC, increasing their .. though this appears to have been due to compensatory modifications expression of sarcomere proteins and ion channels (including Kir2.1), .. that desensitize the mPTP to Ca2þ leak.59 .. was an important advance. .. Lipid accumulation in diabetic and obese patients typically encom- An alternative method that can be used to drive cardiomyocyte matu- .. passes increased cardiac fatty acid (FA) uptake eventually surpassing the .. rity is to culture them for several months on a nan-patterned surface, .. mitochondrial oxidative capacity. Nevertheless, decreased lipolysis via which results in human iPSC-CMs with adult-like dimensions and aligned .. cardiac overexpression of Perilipin 5 (Plin5), a binding partner of .. myofibrils.53 Pioner et al.53 showed that if these cells are derived from a .. Adipose triglyceride lipase (ATGL), is compatible with normal heart Duchenne muscular dystrophy (DMD) patient lacking full-length dystro- .. function and lifespan despite massive cardiac lipid accumulation. .. phin, they have reduced myofibril contractile tension, slower relaxation .. Kolleritsch et al.60 provide evidence that this can be explained by a re- kinetics, and to Ca2þ handling abnormalities, similar to DMD cells. This is .. duction in dynamin-related protein 1 (Drp1)-mediated mitochondrial .. very practical for in vitro investigations of cardiomyocyte-intrinsic genetic .. fission. diseases.53 .. Doxorubicin is a chemotherapeutic drug widely used for treating a va- .. Despite initial enthusiasm in regenerative medicine for the approach .. riety of cancers. However, it causes significant cardiotoxicity and heart of directly injecting cardiomyocytes derived from iPSC into the heart, .. failure. Dhingra et al.61 showed that doxorubicin de-represses nuclear .. this approach has been frustrated by poor survival and/or functional . factor-kB (NF-kB)-mediated suppression of Bnip3 expression. In other Cardiac research in 2020 2169 .. words, it causes increased Bnip3 expression, leading to mitochondrial in- .. artery disease.70 By translating such findings in the anthracycline cardio- jury, including calcium influx, mPTP opening, ROS production, and cell .. toxicity scenario, the authors provided new understandings on the ec- .. death. One interpretation is that maintaining NF-kB signalling may prove .. topic expression of TERT targeting mitochondrial mechanisms, thus beneficial in reducing mitochondrial dysfunction and heart failure in can- .. offering a possible therapeutic approach to promote cardiomyocyte .. cer patients undergoing Doxorubicin chemotherapy. .. preservation. Galan-Arriola et al.62 performed a study of anthracycline-induced car- .. Although doxorubicin is well known for its pleiotropic detrimental .. diotoxicity in pigs and showed that cumulative exposure to doxorubicin .. effects on cardiomyocyte viability and metabolism—including DNA Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 significantly reduced LV ejection fraction and extensive mitochondrial .. damage, generation of ROS, and mitochondria impairment—the details .. fragmentation. Remote ischemic preconditioning (RIPC) applied before .. of the molecular mechanisms underlying its cardiotoxic effects remain each doxorubicin cycle preserved cardiac contractility and LV ejection .. unclear. Nevertheless, this understanding is needed to allow optimiza- .. fraction in long-term cardiac MRI exams. RIPC prevented doxorubicin- .. tion of ad hoc cardioprotective approaches. Han et al.71 recently investi- induced irreversible mitochondrial fragmentation and dysregulated .. gated the role of circular RNAs (circRNAs) in an in vitro system based on .. autophagy. They concluded that RIPC is an attractive strategy for treat- .. iPSC-derived cardiomyocytes exposed to doxorubicin. A circRNA gen- .. erated from the ITCH gene (CircITCH) was found to significantly de- ing anthracycline-induced cardiotoxicity in patients. .. Ritterhoff et al.63 identified a role for metabolic remodelling in cardiac .. crease cardiomyocyte sensitivity to doxorubicin, by antagonizing miR- .. 330-5p and upregulating sirtuin 6, surviving, and SERCA2a expression.71 hypertrophy by using an in vitro model of phenylephrine-induced hyper- .. trophy in primary adult rat cardiomyocytes, and an in vivo model of pres- .. Interestingly, CircITCH was found to be downregulated in hearts from .. patients with doxorubicin -induced cardiomyopathy and in doxorubicin- sure overload-induced cardiac hypertrophy. They found that an increase .. in glucose consumption supports the aspartate synthesis that drives the .. treated iPS-cardiomyocytes. Conversely, AAV9-mediated overexpres- .. sion of human CircITCH in murine hearts counteracted doxorubicin increase of biomass during cardiac hypertrophy. Conversely, preserva- .. tion of fatty acid oxidation prevents this metabolic shift, thus preventing .. detrimental influence on cardiac function, thus raising its potential as a .. cardiac hypertrophy. .. theragnostic candidate for early diagnosis of anthracycline-induced .. cardiotoxicity. .. .. A recent genetic screen conducted in zebrafish shed new light on the 8. Counteracting drug-induced .. role of endothelial cells in antagonizing doxorubicin damage; indeed, reti- .. cardiotoxicity: new insights for ad .. noid X receptor alpha a (i.e. the fish orthologue of the human Retinoid X re- .. ceptor alpha) was shown to exert cardioprotective effects by rescuing .. hoc cardioprotection .. the compromised endothelial barrier in anthracycline-induced cardio- .. toxicity. These findings advocate the relevance of considering cardiovas- Myocardial dysfunction is often reported as a long-term complication of .. .. cular cell lineages other than cardiomyocytes as therapeutic target chemotherapy-based treatments in cancer survivors. For example, .. against drug-related cardiotoxicity.72 In such a perspective, cardiac resi- anthracycline formulations such as doxorubicin are widely used as effec- .. .. dent macrophages were also shown to operate as immune modulators tive oncological drugs against several tumours and cancers; yet, as major .. in reducing adverse cardiac remodelling during doxorubicin-elicited car- drawbacks, they also induce cumulative cardiotoxic effects leading to hy- .. .. diomyopathy, with their self-renewal potential tightly regulated by the pertension, arrhythmias, and congestive heart failure.64–66 Despite recent .. cardioprotective scavenger receptor SR-A1.73 improvements in the field of cardio-oncology, no general consensus has .. .. Last year also witnessed the implementation of 3D cell-based plat- yet been reached on the most effective strategy to maximally exploit on- .. forms to address the unmet need for comprehensive drug screening .. cological drug potential while minimizing cardiac injury. In 2020, a number .. with the evaluation of cardiotoxicity effects. Indeed, a human cardiac of important studies were published describing novel therapeutic and di- .. organoid disease model with chronic adrenergic stimulation was opti- .. agnostic strategies and providing useful insights into the mechanisms un- .. mized by combining iPS-cardiomyocyte biology with a tissue engineering derlying the detrimental effects of doxorubicin on cardiac tissue. .. approach.74 This organotypic construct recapitulated the major features .. Milano et al.67 developed an original, preclinical rat model of .. of ischaemic infarcted myocardium including pathological metabolic chemotherapy-induced cardiotoxicity and chronic ventricular dysfunc- .. shifts, fibrosis and impaired calcium handling.74 Nonetheless, it was also .. tion, based on the dual administration of the monoclonal antibody .. successfully validated to mimic hypoxia-enhanced doxorubicin detrimen- Trastuzumab and doxorubicin, which simulates the current clinical pro- .. .. tal effects, thus offering a useful tool to model drug-induced exacerba- tocol for HER2-positive breast cancer.67 Human cardiac stromal cell- .. tion of cardiotoxicity for oncological patients.74 derived exosomes were administered systemically and repeatedly in- .. .. Timely recognition of the early signs of cancer therapy-derived cardio- between doxorubicin and Trastuzumab doses. Notably, this was able to .. toxicity is of utmost importance to minimize the incidence of myocardial counteract chemotherapy-induced cardiac fibrosis and LV dysfunction, .. .. damage and heart failure in cancer survivors. However, reliable diagnos- while curbing inflammatory cell infiltration by means of the horizontal .. tic markers to rapidly detect the early onset of doxorubicin-induced car- .. transfer of microRNA (miR-146a-5p).67 .. diomyopathy are currently missing. The impairment of cardiac Another thought-provoking therapeutic approach has been recently .. energetics is a major aspect of doxorubicin-related heart failure. In this .. proposed to prevent anthracycline-induced cardiomyopathy by means .. regard, various imaging techniques have been recently proposed to eval- of gene therapy with pharmacological upregulation of telomerase in car- .. uate heart metabolic fluxes and assess cardiac mitochondrial metabo- .. diomyocytes.68 The rationale of this approach was based on the signifi- .. lism. Timm et al.75 recently illustrated the application of hyperpolarized cant pro-survival results obtained following AAV9 gene therapy for .. magnetic resonance imaging (MRI) in a rat preclinical model of .. telomerase (Tert) cardiomyocyte overexpression after MI in the adult .. doxorubicin-induced heart failure. This strategy revealed that a change in mouse,69 along with the TERT polymerase’s function in eliminating mito- .. oxidative carbohydrate metabolism can be used as an advance warning .. chondrial ROS in compromised arterioles of patients with coronary . of myocardial dysfunction due to cardiac mitochondria alterations.75 2170 S.M. Davidson et al. Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 Figure 4 Proposed mechanisms of acute myocardial injury (AMI) related to SARS-CoV-2 infection. AMI may result from primary viral infection of car- diac tissue inducing cytotoxicity and apoptosis of cardiomyocyte cells, or of pericytes and endothelial of the myocardial capillaries resulting in microvascu- lar dysfunction. In addition, AMI may be secondary to systemic inflammation and hypercoagulability—processes that occur during the disease evolution and may derive towards the generation of capillary microthrombi in the heart or epicardial coronary thrombosis. These data open up the possibility of early detection of doxorubicin- .. considered different possibilities ranging from primary viral infection of .. induced cardiac damage in the clinical setting. .. the cardiac tissue to myocardial microvascular dysfunction, microthrom- Cardiotoxicity can be caused by drugs other than chemotherapeutic .. bosis and cardiac damage secondary to lung damage or systemic inflam- .. agents and is, in fact, often the cause for clinical failure or withdrawal of .. mation (massive inflammatory response/cytokine storm) and hypoxia— .. drugs from the market. An interesting approach has been developed to .. processes that occur during disease progression (Figure 4). reveal the ‘hidden cardiotoxicity’ of drugs, which is defined as the cardio- .. SARS-CoV-2 infects human cells via binding of its glycosylated enve- .. toxicity of a drug that manifests in the diseased heart but not in the .. lope spike proteins to the angiotensin converting enzyme 2 (ACE2) re- healthy heart, or as a drug-induced deterioration of cardiac stress adap- .. ceptor of host cells.79 The potential susceptibility of the human heart to .. tation. Brenner et al.76 revisited the COX-2 inhibitor rofecoxib, which .. SARS-CoV-2 infection was evidenced by Chen et al.,80 who showed a was withdrawn from the market due to increased cardiovascular risk, .. consistent presence of ACE2 in cardiac tissue, with expression levels .. and showed that it increased acute mortality in rats subject to ischaemia .. even higher than those in the lung, by carrying out a comparative screen .. and reperfusion, due to its proarrhythmic effect. .. of ACE2 mRNA expression in different human organs based on the .. GTEx database. According to data obtained from single-cell RNA se- .. .. quencing, cardiomyocytes and pericytes were identified as the cells with 9. SARS-CoV-2—a new threat for .. .. the highest expression of ACE2 in the heart, with ACE2 expression the heart? .. detected at a lower level in other major cells isolated from myocardial .. tissue, including endothelial cells, fibroblasts, and leucocytes.80,81 Of .. Coronavirus disease 2019 (COVID-19), caused by the virus SARS-CoV- ... note, Nicin et al.81 identified cardiomyocytes as the cell type with the 2, predominantly affects the respiratory system. Nevertheless, since the .. highest ACE2 expression, with ACE2 levels significantly elevated in the pandemic onset there is accumulating evidence that SARS-CoV-2 infec- .. .. cardiomyocytes of patients with heart disease of different aetiology com- tion frequently presents with cardiovascular complications and acute .. pared to healthy controls. On the contrary, the study by Chen and col- .. myocardial injury,77 as indicated by significantly elevated levels of .. leagues80 revealed the highest ACE2 expression specifically in mural troponin-T and NT-proBNP, associated with greater disease severity .. pericytes. Thus, the authors concluded that pericytes might act as the .. and worse outcomes.78 The underlying mechanisms for cardiac damage .. target cardiac cell of SARS-CoV-2, subsequently disturbing the microvas- in COVID-19 remain uncertain. Studies performed during 2020 .. cular environment of the myocardium. Cardiac research in 2020 2171 .. The hypothesis that SARS-CoV-2 can reside within the heart and, as .. situ-hybridization analysis evidence the presence of virus particles within a consequence, directly induce myocardial injury was evidenced by .. endothelial cells in vessels with and without microthrombi in this study. .. RT-PCR82 and electron microscopy83 in two independent studies, which .. Interestingly, by performing immunohistochemical analysis, Pellegrini et demonstrated the presence of viral particles in cardiac biopsies from .. al.90 found that microthrombi were distinctly different in composition, .. COVID-19 patients. In addition, two studies using human iPSC-CMs pro- .. with greater fibrin and c5-9 complement content, as compared to epi- vided evidence that these cardiomyocytes are susceptible to SARS-CoV- .. cardial coronary thrombus aspirates from STEMI patients. .. 2 infection in vitro via ACE2.84,85 Bojkova et al.84 further demonstrated .. Supporting the effects of SARS-CoV-2 infection on the heart micro- Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 the presence of intracellular double-stranded SARS-CoV-2 RNA and ex- .. vasculature, Maccio et al.91 provided evidence of SARS-CoV-2 specifi- .. pression of the viral spike glycoprotein after incubating human iPSC- .. cally affecting capillaries, arterioles, and venules in a recent post-mortem CMs with two different strains of the virus. In addition, they detected .. study of cardiac tissue from COVID-19 patients. By immunohistochemi- .. viral spike protein expression and viral particles in living human heart .. cal and histological evaluation of the entire coronary tree, the authors slices, derived from explanted hearts, after infection with the SARS- .. identified high endothelial ACE2 receptor expression specifically located .. CoV-2 strains in vitro. SARS-CoV-2 infection-induced cytotoxicity .. in small epicardial vessels and lympho-monocytic inflammation increasing and apoptotic effects associated with decreased a-sarcomeric actinin .. towards the small vessels, without involving the major coronary arteries. .. signal and inhibition of beating of cardiomyocytes in the in vitro stud- .. In addition, Fox et al.92 reported the presence of swollen endothelial ies.85 Furthermore, Bojkova et al. presented evidence that SARS- .. .. cells in small arterioles, capillaries, and venules of hearts obtained from CoV-2 undergoes a full replication cycle when infecting cardiomyo- .. COVID-19 patients, who died of respiratory failure, without identifying cytes and that cathepsins are likely involved, in addition to ACE2, in .. .. large areas of myocyte necrosis, nor significant interstitial lymphocytic cardiomyocyte infection. Interestingly, transcriptional analysis of hu- .. infiltrate. man iPSC-CMs showed that SARS-CoV-2 infection activates immune .. .. Uncontrolled inflammation, associated with high levels of circulating responses, while it inhibits the expression of genes involved in .. cytokines, is thought to be a major cause of disease severity in COVID- .. cellular metabolism and suppresses ACE2 expression. .. 19 and one of the suggested underlying mechanisms to induce cardiac It must be recognized that the relevance of these in vitro studies was in .. damage in COVID-19 patients. In this regard, Basso et al.,93 by perform- .. demonstrating the possibility for iPSC-derived cardiomyocyte infection .. ing a systematic immunohistochemical analysis of cardiac tissue, obtained by SARS-CoV-2, and they do not provide direct evidence of infection of .. at autopsy from patients dying of COVID-19 due to respiratory failure, .. cardiomyocytes in vivo. However, as proof-of-concept, the authors iden- .. evidenced increased interstitial myocardial macrophage infiltration in the tified SARS-CoV-2 particles by electron microscopy in cardiomyocytes .. majority of patients (86%) and changes consistent with lymphocytic .. of an endocardial biopsy sample obtained from a young male .. myocarditis in a small number of cases. The authors suggested that COVID-19 patient with severe lung injury and reduced right and left .. .. increased levels of myocardial macrophages in these COVID-19 ventricular ejection fraction.84 In contrast, however, a more recent .. patients resulted from high systemic levels of pro-inflammatory cyto- study, focussed on post-mortem immunohistochemical, structural, .. .. kines, since no causative relationship between SARS-CoV-2 and and molecular evaluation of cardiac series of patients who died .. myocardial inflammation could be established. Consistent with this from active or cleared SARS-CoV-2 infection, did not find definitive .. .. view, Del Valle et al.94 demonstrated that early cytokine measure- evidence of direct myocardial injury by the virus.86 Instead, Bois et al. .. ments in COVID-19 patients are reliable predictors of disease course highlighted microthrombosis of the small myocardial vasculature in .. .. and outcome. The authors implemented a rapid multiplex cytokine the heart as a relatively common finding in COVID-19 patients even .. assay and analysed blood samples on the day of hospital admission, in the absence of acute ischaemic injury. In this respect, among the .. .. in two independent cohorts of 1484 patients and 231 patients. Their various mechanisms underlying myocardial injury in COVID-19 .. results demonstrated that elevated levels of interleukin (IL)-6 and patients that have been hypothesized since the origin of the disease .. .. tumour necrosis factor (TNF)-a at hospitalization serve as strong in December 2019, the importance of microvascular damage is .. predictors of disease severity and propose their use in stratification increasingly recognized, most likely due to endothelial cell dysfunc- .. .. of patients with COVID-19. tion and formation of microscopic blood clots (summarized in .. .. Ostergaard (2021)87 and Roshdy et al. (2020)88). In addition, acute .. coronary syndrome due to coronary thrombotic events from athero- .. 10. Conclusion .. sclerotic plaque rupture has been confirmed as a major cardiovascu- .. lar clinical manifestation of COVID-19.89 .. As can be seen from the preceding sections, many exciting advances .. were made in cardiology in 2020. We wish to acknowledge the dedica- Systemic hypercoagulability, with major elevation of D-dimer and .. fibrin/fibrinogen-degradation products, is considered a main cause of or- .. tion and determination of the researchers worldwide who have .. gan failure in severe COVID-19 cases. Thus, SARS-CoV-2- induced en- .. produced the outstanding research we have discussed in this review, in dothelial dysfunction may result in a procoagulant condition with .. addition to all the research we did not have space to include. From the .. relevant consequences, either on epicardial coronary thrombosis, or on ... junior postgraduate students travailing in the lab, to the most senior in- generation of capillary microthrombi in the heart. .. ternationally renowned scientific leaders, it is interesting to look back In line with the study by Bois et al.,86 a more recently published sys- .. and see what has been achieved in a difficult year. No doubt, there will .. tematic pathologic analysis of hearts from patients dying of COVID-19 .. be new challenges and changes to navigate—altered research funding infection has reported 35% of cases with evidence of cardiac injury and .. priorities, changed working practises, greater reliance on web-based .. identified microthrombi in myocardial capillaries, arterioles, and small .. communication. But there will also be new opportunities. COVID-19 muscular arteries as the leading cause of myocyte necrosis.90 It is note- .. will surely remain an important topic of investigation, and studies of the .. worthy that neither transmission electronic microscopy (TEM) nor in . potential long-term cardiovascular effects will require investigation. We 2172 S.M. Davidson et al. .. Improving translational research in sex-specific effects of comorbidities and risk fac- look forward to seeing the progress that will be made in cardiovascular .. research in the following years. .. tors in ischaemic heart disease and cardioprotection: position paper and recommen- .. dations of the ESC Working Group on Cellular Biology of the Heart. Cardiovasc Res .. 2021;117:367–385. .. 10. Schreckenberg R, Klein J, Kutsche HS, Schulz R, Gomori K, Bencsik P, Benczik B, Agg Author contributions .. B, Saghy E, Ferdinandy P, Schluter KD. Ischaemic post-conditioning in rats: responder .. and non-responder differ in transcriptome of mitochondrial proteins. J Cell Mol Med .. 2020;24:5528–5541. T.P., S.B., D.D., P.E., I.H., G.V., and S.D. drafted the initial manuscript. .. .. 11. Porrello ER, Mahmoud AI, Simpson E, Hill JA, Richardson JA, Olson EN, Sadek HA. Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 T.G., J.Woj., C.W., J.Wal and all authors revised the manuscript. .. Transient regenerative potential of the neonatal mouse heart. Science 2011;331: .. 1078–1080. .. 12. Volland C, Schott P, Didié M, Männer J, Unsöld B, Toischer K, Schmidt C, Urlaub H, .. Nickels K, Knöll R, Schmidt A, Guan K, Hasenfuß G, Seidler T. Control of p21Cip by Funding .. BRCA1-associated protein is critical for cardiomyocyte cell cycle progression and This work was supported by the Hatter Cardiovascular Institute [to S.M.D.] .. survival. Cardiovasc Res 2020;116:592–604. .. and the British Heart Foundation [PG/18/44/33790 to S.M.D.; RG/19/10/ .. 13. Blom JN, Feng Q. Cardiac repair by epicardial EMT: current targets and a potential 34506 to P.C.E.]. T.P. is funded by the Spanish Ministry of Health-Institute of .. role for the primary cilium. Pharmacol Ther 2018;186:114–129. .. 14. Smart N, Bollini S, Dube KN, Vieira JM, Zhou B, Davidson S, Yellon D, Riegler J, Health Carlos III [PI19/01687] and G.V. by the Spanish Ministry of Science .. Price AN, Lythgoe MF, Pu WT, Riley PR. De novo cardiomyocytes from within the and Innovation [PGC2018-094025-B-I00] and FEDER ‘Una Manera de Hacer .. activated adult heart after injury. Nature 2011;474:640–644. Europa’. S.B. is funded by University of Genova, Genova, Italy, ‘Curiosity .. 15. Aharonov A, Shakked A, Umansky KB, Savidor A, Genzelinakh A, Kain D, .. Lendengolts D, Revach OY, Morikawa Y, Dong J, Levin Y, Geiger B, Martin JF, Driven’ grant. D.J.D. acknowledges support from the Netherlands .. Tzahor E. ERBB2 drives YAP activation and EMT-like processes during cardiac regen- CardioVascular Research Initiative financially supported by the Dutch Heart .. .. eration. Nat Cell Biol 2020;22:1346–1356. Foundation (CVON2014-RECONNECT and CVON2017-ARENA PRIME). .. 16. Wu CC, Jeratsch S, Graumann J, Stainier DYR. Modulation of mammalian cardiomyo- T.J.G. is funded by European Research Council (CoG-2016- .. cyte cytokinesis by the extracellular matrix. Circ Res 2020;127:896–907. InflammaTENSION). .. 17. Henri O, Pouehe C, Houssari M, Galas L, Nicol L, Edwards-Levy F, Henry JP, .. Dumesnil A, Boukhalfa I, Banquet S, Schapman D, Thuillez C, Richard V, Mulder P, .. Brakenhielm E. Selective stimulation of cardiac lymphangiogenesis reduces myocardial Conflict of interest: G.V. and T.P. are co-founders of the Spin-offs .. edema and fibrosis leading to improved cardiac function following myocardial infarc- Glycardial Diagnostics SL. and IVESTATIN Therapeutics SL. J.Wal received .. .. tion. Circulation 2016;133:1484–1497; discussion 1497. honorarium from Daiichi-Sankyo and consultancy fees from Boehringer .. 18. Klotz L, Norman S, Vieira JM, Masters M, Rohling M, Dube KN, Bollini S, Matsuzaki F, Ingelheim. T.J.G. received honoraria from Merck. .. Carr CA, Riley PR. Cardiac lymphatics are heterogeneous in origin and respond to .. injury. Nature 2015;522:62–67. .. 19. Vieira JM, Norman S, Villa Del Campo C, Cahill TJ, Barnette DN, Gunadasa-Rohling Data availability .. M, Johnson LA, Greaves DR, Carr CA, Jackson DG, Riley PR. The cardiac lymphatic No data included. .. system stimulates resolution of inflammation following myocardial infarction. J Clin .. Invest 2018;128:3402–3412. .. .. 20. Liu X, De la Cruz E, Gu X, Balint L, Oxendine-Burns M, Terrones T, Ma W, Kuo References .. HH, Lantz C, Bansal T, Thorp E, Burridge P, Jakus Z, Herz J, Cleaver O, Torres M, .. Oliver G. Lymphoangiocrine signals promote cardiac growth and repair. Nature 2020; 1. Gao C, Wang R, Li B, Guo Y, Yin T, Xia Y, Zhang F, Lian K, Liu Y, Wang H, Zhang L, .. 588:705–711. Gao E, Yan W, Tao L. TXNIP/Redd1 signalling and excessive autophagy: a novel .. 21. Aurora AB, Porrello ER, Tan W, Mahmoud AI, Hill JA, Bassel-Duby R, Sadek HA, mechanism of myocardial ischaemia/reperfusion injury in mice. Cardiovasc Res 2020; .. Olson EN. Macrophages are required for neonatal heart regeneration. J Clin Invest 116:645–657. .. 2014;124:1382–1392. 2. Liu J, Yang C, Liu T, Deng Z, Fang W, Zhang X, Li J, Huang Q, Liu C, Wang Y, Yang .. D, Sukhova GK, Lindholt JS, Diederichsen A, Rasmussen LM, Li D, Newton G, .. 22. Nicolás-Ávila JA, Lechuga-Vieco AV, Esteban-Martı́nez L, Sánchez-Dı́az M, Dı́az- .. Garcı́a E, Santiago DJ, Rubio-Ponce A, Li JL, Balachander A, Quintana JA, Martı́nez- Luscinskas FW, Liu L, Libby P, Wang J, Guo J, Shi GP. Eosinophils improve cardiac .. de-Mena R, Castejón-Vega B, Pun-Garcı́a A, Través PG, Bonzón-Kulichenko E, function after myocardial infarction. Nat Commun 2020;11:6396. .. Garcı́a-Marqués F, Cussó L, A-González N, González-Guerra A, Roche-Molina M, 3. Dehghani T, Thai PN, Sodhi H, Ren L, Sirish P, Nader CE, Timofeyev V, Overton JL, .. Martin-Salamanca S, Crainiciuc G, Guzmán G, Larrazabal J, Herrero-Galán E, Alegre- Li X, Lam KS, Chiamvimonvat N, Panitch A. Selectin-targeting glycosaminoglycan- .. Cebollada J, Lemke G, Rothlin CV, Jimenez-Borreguero LJ, Reyes G, Castrillo A, peptide conjugate limits neutrophil mediated cardiac reperfusion injury. Cardiovasc .. Desco M, Mu~ noz-Cánoves P, Ibá~ nez B, Torres M, Ng LG, Priori SG, Bueno H, Res 2020;cvaa312. .. 4. Mendieta G, Ben-Aicha S, Gutiérrez M, Casani L, Arzanauskaite_ M, Carreras F, .. Vázquez J, Cordero MD, Bernal JA, Enrı́quez JA, Hidalgo A. A network of macro- .. phages supports mitochondrial homeostasis in the heart. Cell 2020;183:94–109.e123. Sabate M, Badimon L, Vilahur G. Intravenous statin administration during myocardial .. 23. Bartelt A, Weber C. Mitochondrial ejection for cardiac protection: the macrophage infarction compared with oral post-infarct administration. J Am Coll Cardiol 2020;75: .. connection. Cell Metab 2020;32:512–513. 1386–1402. .. 24. Li Y, Li H, Pei J, Hu S, Nie Y. Transplantation of murine neonatal cardiac macrophage 5. Li L, Li H, Tien CL, Jain MK, Zhang L. Kruppel-like factor 15 regulates the circadian .. improves adult cardiac repair. Cell Mol Immunol 2021;18:492–494. susceptibility to ischemia reperfusion injury in the heart. Circulation 2020;141: .. 25. Driessen MM, Hui W, Bijnens BH, Dragulescu A, Mertens L, Meijboom FJ, Friedberg 1427–1429. .. MK. Adverse ventricular-ventricular interactions in right ventricular pressure load: 6. Bar C, Chatterjee S, Falcao Pires I, Rodrigues P, Sluijter JPG, Boon RA, Nevado RM, .. .. insights from pediatric pulmonary hypertension versus pulmonary stenosis. Physiol Andres V, Sansonetti M, de Windt L, Ciccarelli M, Hamdani N, Heymans S, Figuinha .. Rep 2016;4:e12833. Videira R, Tocchetti CG, Giacca M, Zacchigna S, Engelhardt S, Dimmeler S, Madonna .. 26. Vriz O, Pirisi M, Bossone E, Fadl ElMula FEM, Palatini P, Naeije R. Right ventricular- R, Thum T. Non-coding RNAs: update on mechanisms and therapeutic targets from .. pulmonary arterial uncoupling in mild-to-moderate systemic hypertension. J the ESC Working Groups of Myocardial Function and Cellular Biology of the Heart. .. Hypertens 2020;38:274–281. Cardiovasc Res 2020;116:1805–1819. .. 27. Ye L, Wang S, Xiao Y, Jiang C, Huang Y, Chen H, Zhang H, Zhang H, Liu J, Xu Z, 7. Viereck J, Bührke A, Foinquinos A, Chatterjee S, Kleeberger JA, Xiao K, Janssen- .. Hong H. Pressure overload greatly promotes neonatal right ventricular cardiomyo- Peters H, Batkai S, Ramanujam D, Kraft T, Cebotari S, Gueler F, Beyer AM, Schmitz J, .. .. cyte proliferation: a new model for the study of heart regeneration. J Am Heart Assoc Bräsen JH, Schmitto JD, Gyöngyösi M, Löser A, Hirt MN, Eschenhagen T, Engelhardt .. 2020;9:e015574. S, Bär C, Thum T. Targeting muscle-enriched long non-coding RNA H19 reverses .. 28. Kupfer ME, Lin WH, Ravikumar V, Qiu K, Wang L, Gao L, Bhuiyan DB, Lenz M, Ai J, pathological cardiac hypertrophy. Eur Heart J 2020;41:3462–3474. .. Mahutga RR, Townsend D, Zhang J, McAlpine MC, Tolkacheva EG, Ogle BM. In situ 8. Lin H, Li Y, Zhu H, Wang Q, Chen Z, Chen L, Zhu Y, Zheng C, Wang Y, Liao W, .. expansion, differentiation, and electromechanical coupling of human cardiac muscle Bin J, Kitakaze M, Liao Y. Lansoprazole alleviates pressure overload-induced cardiac .. in a 3D bioprinted, chambered organoid. Circ Res 2020;127:207–224. hypertrophy and heart failure in mice by blocking the activation of beta-catenin. .. 29. Huang K, Ozpinar EW, Su T, Tang J, Shen D, Qiao L, Hu S, Li Z, Liang H, Mathews K, Cardiovasc Res 2020;116:101–113. .. Scharf V, Freytes DO, Cheng K. An off-the-shelf artificial cardiac patch improves car- .. 9. Perrino C, Ferdinandy P, Bøtker HE, Brundel BJJM, Collins P, Davidson SM, den .. diac repair after myocardial infarction in rats and pigs. Sci Transl Med 2020;12: Ruijter HM, Engel FB, Gerdts E, Girao H, Gyöngyösi M, Hausenloy DJ, Lecour S, .. eaat9683. Madonna R, Marber M, Murphy E, Pesce M, Regitz-Zagrosek V, Sluijter JPG, Steffens .. 30. Han X, Zhou Z, Fei L, Sun H, Wang R, Chen Y, Chen H, Wang J, Tang H, Ge W, S, Gollmann-Tepeköylü C, Van Laake LW, Van Linthout S, Schulz R, Ytrehus K. . Zhou Y, Ye F, Jiang M, Wu J, Xiao Y, Jia X, Zhang T, Ma X, Zhang Q, Bai X, Lai S, Yu Cardiac research in 2020 2173 C, Zhu L, Lin R, Gao Y, Wang M, Wu Y, Zhang J, Zhan R, Zhu S, Hu H, Wang C, .. 48. Liu S, Chen X, Bao L, Liu T, Yuan P, Yang X, Qiu X, Gooding JJ, Bai Y, Xiao J, Pu F, .. Chen M, Huang H, Liang T, Chen J, Wang W, Zhang D, Guo G. Construction of a .. Jin Y. Treatment of infarcted heart tissue via the capture and local delivery of circu- human cell landscape at single-cell level. Nature 2020;581:303–309. .. lating exosomes through antibody-conjugated magnetic nanoparticles. Nat Biomed 31. Litvinuková M, Talavera-López C, Maatz H, Reichart D, Worth CL, Lindberg EL, .. Eng 2020;4:1063–1075. Kanda M, Polanski K, Heinig M, Lee M, Nadelmann ER, Roberts K, Tuck L, Fasouli ES, .. 49. Chandy M, Rhee JW, Ozen MO, Williams DR, Pepic L, Liu C, Zhang H, Malisa J, Lau DeLaughter DM, McDonough B, Wakimoto H, Gorham JM, Samari S, Mahbubani KT, .. E, Demirci U, Wu JC. Atlas of exosomal microRNAs secreted from human iPSC- Saeb-Parsy K, Patone G, Boyle JJ, Zhang H, Zhang H, Viveiros A, Oudit GY, .. derived cardiac cell types. Circulation 2020;142:1794–1796. .. Bayraktar OA, Seidman JG, Seidman CE, Noseda M, Hubner N, Teichmann SA. Cells .. 50. Benzoni P, Campostrini G, Landi S, Bertini V, Marchina E, Iascone M, Ahlberg G, of the adult human heart. Nature 2020;588:466–472. .. Olesen MS, Crescini E, Mora C, Bisleri G, Muneretto C, Ronca R, Presta M, Poliani Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 32. Ruiz-Villalba A, Romero JP, Hernández SC, Vilas-Zornoza A, Fortelny N, Castro- .. PL, Piovani G, Verardi R, Di Pasquale E, Consiglio A, Raya A, Torre E, Lodrini AM, Labrador L, San Martin-Uriz P, Lorenzo-Vivas E, Garcı́a-Olloqui P, Palacio M, Gavira .. Milanesi R, Rocchetti M, Baruscotti M, DiFrancesco D, Memo M, Barbuti A, Dell’Era JJ, Bastarrika G, Janssens S, Wu M, Iglesias E, Abizanda G, de Morentin XM, Lasaga M, .. P. Human iPSC modelling of a familial form of atrial fibrillation reveals a gain of func- Planell N, Bock C, Alignani D, Medal G, Prudovsky I, Jin Y-R, Ryzhov S, Yin H, .. tion of If and ICaL in patient-derived cardiomyocytes. Cardiovasc Res 2020;116: Pelacho B, Gomez-Cabrero D, Lindner V, Lara-Astiaso D, Prósper F. Single-cell RNA .. 1147–1160. .. sequencing analysis reveals a crucial role for CTHRC1 (collagen triple helix repeat .. 51. Goversen B, van der Heyden MAG, van Veen TAB, de Boer TP. The immature elec- containing 1) cardiac fibroblasts after myocardial infarction. Circulation 2020;142: .. trophysiological phenotype of iPSC-CMs still hampers in vitro drug screening: special 1831–1847. .. focus on IK1. Pharmacol Ther 2018;183:127–136. 33. Suryawanshi H, Clancy R, Morozov P, Halushka MK, Buyon JP, Tuschl T. Cell atlas of .. 52. Garbern JC, Helman A, Sereda R, Sarikhani M, Ahmed A, Escalante GO, Ogurlu R, the foetal human heart and implications for autoimmune-mediated congenital heart .. Kim SL, Zimmerman JF, Cho A, MacQueen L, Bezzerides VJ, Parker KK, Melton DA, block. Cardiovasc Res 2020;116:1446–1457. .. Lee RT. Inhibition of mTOR signaling enhances maturation of cardiomyocytes de- 34. Peet C, Ivetic A, Bromage DI, Shah AM. Cardiac monocytes and macrophages after .. .. rived from human-induced pluripotent stem cells via p53-induced quiescence. myocardial infarction. Cardiovasc Res 2020;116:1101–1112. .. Circulation 2020;141:285–300. 35. Bevan L, Lim ZW, Venkatesh B, Riley PR, Martin P, Richardson RJ. Specific macro- .. 53. Pioner JM, Guan X, Klaiman JM, Racca AW, Pabon L, Muskheli V, Macadangdang J, phage populations promote both cardiac scar deposition and subsequent resolution .. Ferrantini C, Hoopmann MR, Moritz RL, Kim DH, Tesi C, Poggesi C, Murry CE, in adult zebrafish. Cardiovasc Res 2020;116:1357–1371. .. Childers MK, Mack DL, Regnier M. Absence of full-length dystrophin impairs normal 36. Vagnozzi RJ, Maillet M, Sargent MA, Khalil H, Johansen AKZ, Schwanekamp JA, York .. maturation and contraction of cardiomyocytes derived from human-induced pluripo- AJ, Huang V, Nahrendorf M, Sadayappan S, Molkentin JD. An acute immune response .. tent stem cells. Cardiovasc Res 2020;116:368–382. .. underlies the benefit of cardiac stem cell therapy. Nature 2020;577:405–409. .. 54. Lou X, Zhao M, Fan C, Fast VG, Valarmathi MT, Zhu W, Zhang J. N-cadherin over- 37. Zhao J, Florentin J, Tai YY, Torrino S, Ohayon L, Brzoska T, Tang Y, Yang J, Negi V, .. expression enhances the reparative potency of human-induced pluripotent stem cell- Woodcock CC, Risbano MG, Nouraie SM, Sundd P, Bertero T, Dutta P, Chan SY. .. derived cardiac myocytes in infarcted mouse hearts. Cardiovasc Res 2020;116: Long range endocrine delivery of circulating miR-210 to endothelium promotes pul- .. 671–685. monary hypertension. Circ Res 2020;127:677–692. .. 55. Tao Z, Loo S, Su L, Tan S, Tee G, Gan SU, Zhang J, Chen X, Ye L. Angiopoietin-1 en- 38. Aghajanian H, Kimura T, Rurik JG, Hancock AS, Leibowitz MS, Li L, Scholler J, .. hanced myocyte mitosis, engraftment, and the reparability of hiPSC-CMs for treat- Monslow J, Lo A, Han W, Wang T, Bedi K, Morley MP, Linares Saldana RA, Bolar .. ment of myocardial infarction. Cardiovasc Res 2021;117:1578–1591. .. NA, McDaid K, Assenmacher CA, Smith CL, Wirth D, June CH, Margulies KB, Jain R, .. 56. Huo J, Lu S, Kwong JQ, Bround MJ, Grimes KM, Sargent MA, Brown ME, Davis ME, Pure E, Albelda SM, Epstein JA. Targeting cardiac fibrosis with engineered T cells. .. Bers DM, Molkentin JD. MCUb induction protects the heart from postischemic Nature 2019;573:430–433. .. remodeling. Circ Res 2020;127:379–390. 39. Moreira LM, Takawale A, Hulsurkar M, Menassa DA, Antanaviciute A, Lahiri SK, .. 57. Puente BN, Sun J, Parks RJ, Fergusson MM, Liu C, Springer DA, Aponte AM, Liu JC, Mehta N, Evans N, Psarros C, Robinson P, Sparrow AJ, Gillis MA, Ashley N, Naud P, .. Murphy E. MICU3 plays an important role in cardiovascular function. Circ Res 2020; Barallobre-Barreiro J, Theofilatos K, Lee A, Norris M, Clarke MV, Russell PK, Casadei .. 127:1571–1573. B, Bhattacharya S, Zajac JD, Davey RA, Sirois M, Mead A, Simmons A, Mayr M, .. 58. Pan X, Liu J, Nguyen T, Liu C, Sun J, Teng Y, Fergusson MM, Rovira II, Allen M, .. Sayeed R, Krasopoulos G, Redwood C, Channon KM, Tardif JC, Wehrens XHT, .. Springer DA, Aponte AM, Gucek M, Balaban RS, Murphy E, Finkel T. The physiologi- Nattel S, Reilly S. Paracrine signalling by cardiac calcitonin controls atrial fibrogenesis .. cal role of mitochondrial calcium revealed by mice lacking the mitochondrial calcium and arrhythmia. Nature 2020;587:460–465. .. uniporter. Nat Cell Biol 2013;15:1464–1472. 40. Yan W, Lin C, Guo Y, Chen Y, Du Y, Lau WB, Xia Y, Zhang F, Su R, Gao E, Wang Y, .. 59. Parks RJ, Menazza S, Holmstrom KM, Amanakis G, Fergusson M, Ma H, Aponte AM, Li C, Liu R, Ma XL, Tao L. N-cadherin overexpression mobilizes the protective .. Bernardi P, Finkel T, Murphy E. Cyclophilin D-mediated regulation of the permeabil- effects of mesenchymal stromal cells against ischemic heart injury through a beta- .. ity transition pore is altered in mice lacking the mitochondrial calcium uniporter. .. catenin-dependent manner. Circ Res 2020;126:857–874. .. Cardiovasc Res 2019;115:385–394. 41. Gao L, Mei S, Zhang S, Qin Q, Li H, Liao Y, Fan H, Liu Z, Zhu H. Cardio-renal exo- .. 60. Kolleritsch S, Kien B, Schoiswohl G, Diwoky C, Schreiber R, Heier C, Maresch LK, somes in myocardial infarction serum regulate proangiogenic paracrine signaling in .. Schweiger M, Eichmann TO, Stryeck S, Krenn P, Tomin T, Schittmayer M, Kolb D, adipose mesenchymal stem cells. Theranostics 2020;10:1060–1073. .. Rulicke T, Hoefler G, Wolinski H, Madl T, Birner-Gruenberger R, Haemmerle G. 42. Kurtzwald-Josefson E, Zeevi-Levin N, Rubchevsky V, Bechar Erdman N, Schwartz .. Low cardiac lipolysis reduces mitochondrial fission and prevents lipotoxic heart dys- Rohaker O, Nahum O, Hochhauser E, Ben-Avraham B, Itskovitz-Eldor J, Aravot D, .. function in Perilipin 5 mutant mice. Cardiovasc Res 2020;116:339–352. Barac YD. Cardiac fibroblast-induced pluripotent stem cell-derived exosomes as a .. 61. Dhingra R, Guberman M, Rabinovich-Nikitin I, Gerstein J, Margulets V, Gang H, .. potential therapeutic mean for heart failure. Int J Mol Sci 2020;21:7215. .. Madden N, Thliveris J, Kirshenbaum LA. Impaired NF-kappaB signalling underlies 43. Lew JK, Pearson JT, Saw E, Tsuchimochi H, Wei M, Ghosh N, Du CK, Zhan DY, Jin .. cyclophilin D-mediated mitochondrial permeability transition pore opening in doxo- M, Umetani K, Shirai M, Katare R, Schwenke DO. Exercise regulates microRNAs to .. rubicin cardiomyopathy. Cardiovasc Res 2020;116:1161–1174. preserve coronary and cardiac function in the diabetic heart. Circ Res 2020;127: .. 62. Galan-Arriola C, Villena-Gutierrez R, Higuero-Verdejo MI, Diaz-Rengifo IA, Pizarro 1384–1400. .. G, Lopez GJ, de Molina-Iracheta A, Perez-Martinez C, Garcia RD, Gonzalez-Calle D, 44. Li H, Xu JD, Fang XH, Zhu JN, Yang J, Pan R, Yuan SJ, Zeng N, Yang ZZ, Yang H, .. Lobo M, Sanchez PL, Oliver E, Cordoba R, Fuster V, Sanchez-Gonzalez J, Ibanez B. Wang XP, Duan JZ, Wang S, Luo JF, Wu SL, Shan ZX. Circular RNA .. .. Remote ischemic preconditioning ameliorates anthracycline-induced cardiotoxicity circRNA_000203 aggravates cardiac hypertrophy via suppressing miR-26b-5p and .. and preserves mitochondrial integrity. Cardiovasc Res 2021;117:1132–1143. miR-140-3p binding to Gata4. Cardiovasc Res 2020;116:1323–1334. .. 63. Ritterhoff J, Young S, Villet O, Shao D, Neto FC, Bettcher LF, Hsu YA, Kolwicz SC, 45. Huang P, Wang L, Li Q, Tian X, Xu J, Xu J, Xiong Y, Chen G, Qian H, Jin C, Yu Y, .. Jr., Raftery D, Tian R. Metabolic remodeling promotes cardiac hypertrophy by direct- Cheng K, Qian L, Yang Y. Atorvastatin enhances the therapeutic efficacy of mesen- .. ing glucose to aspartate biosynthesis. Circ Res 2020;126:182–196. chymal stem cells-derived exosomes in acute myocardial infarction via up-regulating .. 64. McGowan JV, Chung R, Maulik A, Piotrowska I, Walker JM, Yellon DM. long non-coding RNA H19. Cardiovasc Res 2020;116:353–367. .. Anthracycline chemotherapy and cardiotoxicity. Cardiovasc Drugs Ther 2017;31: .. 46. Kagaya Y, Ito K, Takahashi J, Matsumoto Y, Shiroto T, Tsuburaya R, Kikuchi Y, Hao K, .. 63–75. Nishimiya K, Shindo T, Ogata T, Kurosawa R, Eguchi K, Monma Y, Ichijo S, Hatanaka .. 65. Galan-Arriola C, Vilchez-Tschischke JP, Lobo M, Lopez GJ, de Molina-Iracheta A, K, Miyata S, Shimokawa H. Low-energy cardiac shockwave therapy to suppress left .. Perez-Martinez C, Villena-Gutierrez R, Macias A, Diaz-Rengifo IA, Oliver E, Fuster V, ventricular remodeling in patients with acute myocardial infarction: a first-in-human .. Sanchez-Gonzalez J, Ibanez B. Coronary microcirculation damage in anthracycline study. Coron Artery Dis 2018;29:294–300. .. cardiotoxicity. Cardiovasc Res 2021:cvab053. 47. Gollmann-Tepekoylu C, Polzl L, Graber M, Hirsch J, Nagele F, Lobenwein D, Hess .. 66. Raber I, Asnani A. Cardioprotection in cancer therapy: novel insights with anthracy- MW, Blumer MJ, Kirchmair E, Zipperle J, Hromada C, Muhleder S, Hackl H, .. clines. Cardiovasc Res 2019;115:915–921. .. Hermann M, Al Khamisi H, Forster M, Lichtenauer M, Mittermayr R, Paulus P, Fritsch .. 67. Milano G, Biemmi V, Lazzarini E, Balbi C, Ciullo A, Bolis S, Ameri P, Di Silvestre D, H, Bonaros N, Kirchmair R, Sluijter JPG, Davidson S, Grimm M, Holfeld J. miR-19a- .. Mauri P, Barile L, Vassalli G. Intravenous administration of cardiac progenitor cell- 3p containing exosomes improve function of ischaemic myocardium upon shock .. derived exosomes protects against doxorubicin/trastuzumab-induced cardiac toxic- wave therapy. Cardiovasc Res 2020;116:1226–1236. . ity. Cardiovasc Res 2020;116:383–392. 2174 S.M. Davidson et al. 68. Chatterjee S, Hofer T, Costa A, Lu D, Batkai S, Gupta SK, Bolesani E, Zweigerdt R, .. 81. Nicin L, Abplanalp WT, Mellentin H, Kattih B, Tombor L, John D, Schmitto JD, Megias D, Streckfuss-Bomeke K, Brandenberger C, Thum T, Bar C. Telomerase ther- .. Heineke J, Emrich F, Arsalan M, Holubec T, Walther T, Zeiher AM, Dimmeler S. Cell apy attenuates cardiotoxic effects of doxorubicin. Mol Ther 2021;29:1395–1410. .. type-specific expression of the putative SARS-CoV-2 receptor ACE2 in human .. 69. Bar C, Bernardes de Jesus B, Serrano R, Tejera A, Ayuso E, Jimenez V, Formentini I, .. hearts. Eur Heart J 2020;41:1804–1806. Bobadilla M, Mizrahi J, de Martino A, Gomez G, Pisano D, Mulero F, Wollert KC, .. 82. Wenzel P, Kopp S, Gobel S, Jansen T, Geyer M, Hahn F, Kreitner KF, Escher F, Bosch F, Blasco MA. Telomerase expression confers cardioprotection in the adult .. Schultheiss HP, Munzel T. Evidence of SARS-CoV-2 mRNA in endomyocardial biop- mouse heart after acute myocardial infarction. Nat Commun 2014;5:5863. .. sies of patients with clinically suspected myocarditis tested negative for COVID-19 in 70. Beyer AM, Freed JK, Durand MJ, Riedel M, Ait-Aissa K, Green P, Hockenberry JC, .. nasopharyngeal swab. Cardiovasc Res 2020;116:1661–1663. Morgan RG, Donato AJ, Peleg R, Gasparri M, Rokkas CK, Santos JH, Priel E, .. 83. Tavazzi G, Pellegrini C, Maurelli M, Belliato M, Sciutti F, Bottazzi A, Sepe PA, Resasco .. Downloaded from https://academic.oup.com/cardiovascres/article/117/10/2161/6296603 by Fundacio Biblioteca Josep Laporte user on 13 February 2023 Gutterman DD. Critical role for telomerase in the mechanism of flow-mediated dila- T, Camporotondo R, Bruno R, Baldanti F, Paolucci S, Pelenghi S, Iotti GA, Mojoli F, .. tion in the human microcirculation. Circ Res 2016;118:856–866. .. Arbustini E. Myocardial localization of coronavirus in COVID-19 cardiogenic shock. 71. Han D, Wang Y, Wang Y, Dai X, Zhou T, Chen J, Tao B, Zhang J, Cao F. The tumor- .. Eur J Heart Fail 2020;22:911–915. suppressive human circular RNA CircITCH sponges miR-330-5p to ameliorate .. 84. Bojkova D, Wagner JUG, Shumliakivska M, Aslan GS, Saleem U, Hansen A, Luxan G, doxorubicin-induced cardiotoxicity through upregulating SIRT6, Survivin, and .. Gunther S, Pham MD, Krishnan J, Harter PN, Ermel UH, Frangakis AS, Milting H, SERCA2a. Circ Res 2020;127:e108–e125. .. Zeiher AM, Klingel K, Cinatl J, Dendorfer A, Eschenhagen T, Tschope C, Ciesek S, 72. Ma X, Zhu P, Ding Y, Zhang H, Qiu Q, Dvornikov AV, Wang Z, Kim M, Wang Y, .. Dimmeler S. SARS-CoV-2 infects and induces cytotoxic effects in human cardiomyo- Lowerison M, Yu Y, Norton N, Herrmann J, Ekker SC, Hsiai TK, Lin X, Xu X. .. cytes. Cardiovasc Res 2020;116:2207–2215. .. Retinoid X receptor alpha is a spatiotemporally predominant therapeutic target for .. 85. Sharma A, Garcia G Jr, Wang Y, Plummer JT, Morizono K, Arumugaswami V, anthracycline-induced cardiotoxicity. Sci Adv 2020;6:eaay2939. .. Svendsen CN. Human iPSC-derived cardiomyocytes are susceptible to SARS-CoV-2 73. Wang R, Lohray R, Chow E, Gangupantula P, Smith L, Draper R. Selective uptake of .. infection. Cell Rep Med 2020;1:100052. carboxylated multi-walled carbon nanotubes by class A type 1 scavenger receptors .. 86. Bois MC, Boire NA, Layman AJ, Aubry MC, Alexander MP, Roden AC, Hagen CE, and impaired phagocytosis in alveolar macrophages. Nanomaterials (Basel) 2020;10: .. Quinton RA, Larsen C, Erben Y, Majumdar R, Jenkins SM, Kipp BR, Lin PT, 2417. .. Maleszewski JJ. COVID-19-associated nonocclusive fibrin microthrombi in the heart. 74. Richards DJ, Li Y, Kerr CM, Yao J, Beeson GC, Coyle RC, Chen X, Jia J, Damon B, .. Circulation 2021;143:230–243. Wilson R, Starr Hazard E, Hardiman G, Menick DR, Beeson CC, Yao H, Ye T, Mei Y. .. 87. Ostergaard L. SARS CoV-2 related microvascular damage and symptoms during and .. Human cardiac organoids for the modelling of myocardial infarction and drug cardio- .. after COVID-19: consequences of capillary transit-time changes, tissue hypoxia and toxicity. Nat Biomed Eng 2020;4:446–462. .. inflammation. Physiol Rep 2021;9:e14726. 75. Timm KN, Perera C, Ball V, Henry JA, Miller JJ, Kerr M, West JA, Sharma E, .. 88. Roshdy A, Zaher S, Fayed H, Coghlan JG. COVID-19 and the heart: a systematic re- Broxholme J, Logan A, Savic D, Dodd MS, Griffin JL, Murphy MP, Heather LC, Tyler .. view of cardiac autopsies. Front Cardiovasc Med 2020;7:626975. DJ. Early detection of doxorubicin-induced cardiotoxicity in rats by its cardiac meta- .. 89. Stefanini GG, Montorfano M, Trabattoni D, Andreini D, Ferrante G, Ancona M, bolic signature assessed with hyperpolarized MRI. Commun Biol 2020;3:692. .. Metra M, Curello S, Maffeo D, Pero G, Cacucci M, Assanelli E, Bellini B, Russo F, 76. Brenner GB, Makkos A, Nagy CT, Onodi Z, Sayour NV, Gergely TG, Kiss B, Gorbe .. Ielasi A, Tespili M, Danzi GB, Vandoni P, Bollati M, Barbieri L, Oreglia J, Lettieri C, .. A, Saghy E, Zadori ZS, Lazar B, Baranyai T, Varga RS, Husti Z, Varro A, Tothfalusi L, .. Cremonesi A, Carugo S, Reimers B, Condorelli G, Chieffo A. ST-elevation myocar- Schulz R, Baczko I, Giricz Z, Ferdinandy P. Hidden cardiotoxicity of rofecoxib can be .. dial infarction in patients with COVID-19: clinical and angiographic outcomes. revealed in experimental models of ischemia/reperfusion. Cells 2020;9:551. .. Circulation 2020;141:2113–2116. 77. Guzik TJ, Mohiddin SA, Dimarco A, Patel V, Savvatis K, Marelli-Berg FM, Madhur MS, .. 90. Pellegrini D, Kawakami R, Guagliumi G, Sakamoto A, Kawai K, Gianatti A, Nasr A, Tomaszewski M, Maffia P, D’Acquisto F, Nicklin SA, Marian AJ, Nosalski R, Murray .. Kutys R, Guo L, Cornelissen A, Faggi L, Mori M, Sato Y, Pescetelli I, Brivio M, EC, Guzik B, Berry C, Touyz RM, Kreutz R, Wang DW, Bhella D, Sagliocco O, Crea .. Romero M, Virmani R, Finn AV. Microthrombi as a major cause of cardiac injury in F, Thomson EC, McInnes IB. COVID-19 and the cardiovascular system: implications .. COVID-19: a pathologic study. Circulation 2021;143:1031–1042. for risk assessment, diagnosis, and treatment options. Cardiovasc Res 2020;116: .. 91. Maccio U, Zinkernagel AS, Shambat SM, Zeng X, Cathomas G, Ruschitzka F, .. 1666–1687. .. Schuepbach RA, Moch H, Varga Z. SARS-CoV-2 leads to a small vessel endotheliitis 78. Giustino G, Croft LB, Stefanini GG, Bragato R, Silbiger JJ, Vicenzi M, Danilov T, Kukar .. in the heart. EBioMedicine 2021;63:103182. N, Shaban N, Kini A, Camaj A, Bienstock SW, Rashed ER, Rahman K, Oates CP, .. 92. Fox SE, Li G, Akmatbekov A, Harbert JL, Lameira FS, Brown JQ, Vander Heide RS. Buckley S, Elbaum LS, Arkonac D, Fiter R, Singh R, Li E, Razuk V, Robinson SE, Miller .. Unexpected features of cardiac pathology in COVID-19 infection. Circulation 2020; M, Bier B, Donghi V, Pisaniello M, Mantovani R, Pinto G, Rota I, Baggio S, Chiarito M, .. 142:1123–1125. Fazzari F, Cusmano I, Curzi M, Ro R, Malick W, Kamran M, Kohli-Seth R, Bassily- .. 93. Basso C, Leone O, Rizzo S, De Gaspari M, van der Wal AC, Aubry MC, Bois MC, Lin Marcus AM, Neibart E, Serrao G, Perk G, Mancini D, Reddy VY, Pinney SP, Dangas .. PT, Maleszewski JJ, Stone JR. Pathological features of COVID-19-associated myocar- .. G, Blasi F, Sharma SK, Mehran R, Condorelli G, Stone GW, Fuster V, Lerakis S, .. dial injury: a multicentre cardiovascular pathology study. Eur Heart J 2020;41: Goldman ME. Characterization of myocardial injury in patients with COVID-19. J Am .. 3827–3835. Coll Cardiol 2020;76:2043–2055. .. 94. Del Valle DM, Kim-Schulze S, Huang HH, Beckmann ND, Nirenberg S, Wang B, 79. Yan R, Zhang Y, Li Y, Xia L, Guo Y, Zhou Q. Structural basis for the recognition of .. Lavin Y, Swartz TH, Madduri D, Stock A, Marron TU, Xie H, Patel M, Tuballes K, SARS-CoV-2 by full-length human ACE2. Science 2020;367:1444–1448. .. Van Oekelen O, Rahman A, Kovatch P, Aberg JA, Schadt E, Jagannath S, Mazumdar 80. Chen L, Li X, Chen M, Feng Y, Xiong C. The ACE2 expression in human heart indi- .. M, Charney AW, Firpo-Betancourt A, Mendu DR, Jhang J, Reich D, Sigel K, Cordon- cates new potential mechanism of heart injury among patients infected with SARS- .. Cardo C, Feldmann M, Parekh S, Merad M, Gnjatic S. An inflammatory cytokine sig- CoV-2. Cardiovasc Res 2020;116:1097–1100. .. nature predicts COVID-19 severity and survival. Nat Med 2020;26:1636–1643.