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Macrophages are most important immune cell population in the heart. Cardiac macrophages have broad-spectrum and heterogeneity, with two extreme polarization phenotypes: M1 pro-inflammatory macrophages (CCR2 - ly6C hi ) and M2 anti-inflammatory macrophages (CCR2 - ly6C lo ). Cardiac macrophages can reshape their polarization states or phenotypes to adapt to their surrounding microenvironment by altering metabolic reprogramming. The phenotypes and polarization states of cardiac macrophages can be defined by specific signature markers on the cell surface, including tumor necrosis factor α, interleukin (IL)-1β, inducible nitric oxide synthase (iNOS), C-C chemokine receptor type (CCR)2, IL-4 and arginase (Arg)1, among them, CCR2 +/- is one of most important markers which is used to distinguish between resident and non-resident cardiac macrophage as well as macrophage polarization states. Dedicated balance between M1 and M2 cardiac macrophages are crucial for maintaining heart development and cardiac functional and electric homeostasis, and imbalance between macrophage phenotypes may result in heart ventricular remodeling and various heart diseases. The therapy aiming at specific target on macrophage phenotype is a promising strategy for treatment of heart diseases. In this article, we comprehensively review cardiac macrophage phenotype, metabolic reprogramming, and their role in maintaining heart health and mediating ventricular remodeling and potential therapeutic strategy in heart diseases., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Kang, Jia, Feng, Ren, Gao, Liu, Zhang and Zhou.)

Systemic lupus erythematosus (SLE) is a prevalent autoimmune disease primarily characterized by the involvement of multiple systems and organs. Cardiovascular disease is the primary cause of mortality in patients with SLE, though the mechanisms underlying the increased cardiovascular risk in SLE patients remain unclear. Recent studies indicate that abnormal activation of programmed cell death (PCD) signaling and the crosstalk among various forms of cell death are critical in the immunopathogenesis of SLE. Furthermore, apoptosis, necroptosis, pyroptosis, NETosis, and ferroptosis are recognized as key cellular processes in the pathogenesis of SLE and are closely linked to cardiac involvement. This review uniquely explores the intricate crosstalk between apoptosis, necroptosis, and other cell death pathways, discussing their roles and interactions in the pathogenesis of cardiac involvement in SLE. Investigating the interplay between PCD signaling and cardiac involvement in SLE in understanding the disease's underlying mechanisms and offers opportunities for new therapeutic interventions. The integration of precision medicine and innovative strategies targeting these complex pathways holds promise for enhancing the treatment prospects of SLE with cardiac involvement., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wei, Wang, Li, Li, Yu, Li, Wang, Wang and Zhu.)

The medical burden of stroke extends beyond the brain injury itself and is largely determined by chronic comorbidities that develop secondarily. We hypothesized that these comorbidities might share a common immunological cause, yet chronic effects post-stroke on systemic immunity are underexplored. Here, we identify myeloid innate immune memory as a cause of remote organ dysfunction after stroke. Single-cell sequencing revealed persistent pro-inflammatory changes in monocytes/macrophages in multiple organs up to 3 months after brain injury, notably in the heart, leading to cardiac fibrosis and dysfunction in both mice and stroke patients. IL-1β was identified as a key driver of epigenetic changes in innate immune memory. These changes could be transplanted to naive mice, inducing cardiac dysfunction. By neutralizing post-stroke IL-1β or blocking pro-inflammatory monocyte trafficking with a CCR2/5 inhibitor, we prevented post-stroke cardiac dysfunction. Such immune-targeted therapies could potentially prevent various IL-1β-mediated comorbidities, offering a framework for secondary prevention immunotherapy., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Cardiac troponin is extensively used as a biomarker in modern medicine due to its diagnostic capability for myocardial injury, as well as its predictive and prognostic value for cardiac diseases. However, heterophile antibodies, antitroponin antibodies, and macrotroponin complexes can be observed both in seemingly healthy individuals and patients with cardiac diseases, potentially leading to false positive or disproportionate elevation of cTn (cardiac troponin) assay results and introducing discrepancies in clinical interpretations with impact on medical management. In this review article, we describe the possible mechanisms of cTn release and the sources of variations in the assessment of circulating cTn levels. We also explore the pathophysiological mechanisms underlying antitroponin antibody development and discuss the influence exerted by macrotroponin complexes on the results of immunoassays. Additionally, we explore approaches to detect these complexes by presenting various clinical scenarios encountered in routine clinical practice. Finally, unsolved questions about the development, prevalence, and clinical significance of cardiac autoantibodies are discussed.

Competing Interests: Disclosures C. Maack received speaker or consultancy honoraria from Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol Myer Squibb, Novartis, Novo Nordisk, Pharmacosmos, Pfizer, and Servier. The other authors report no conflicts.

Over the past 30 years, the field of cardioimmunology has moved from being dismissed as a field that was chasing an epiphenomenon of little biological consequence to a scientific discipline that is providing important new insights into the immunologic basis for hypertension, atherosclerosis, myocarditis, pericarditis, autoimmune heart disease, and heart failure. In this article, we will review the conceptual insights and technical breakthroughs that have allowed the field to move forward, as well as the clinical trials in the cardioimmunology space, to provide a historical context for the articles that will appear in the compendium that is focused on the interface between cardioimmunology, myocardial function, and disease., Competing Interests: Disclosures None.

Cardiovascular diseases remain the largest cause of death worldwide with recent evidence increasingly attributing the development and progression of these diseases to an exacerbated inflammatory response. As a result, significant research is now focused on modifying the immune environment to prevent the disease progression. This in turn has highlighted the lymphatic system in the pathophysiology of cardiovascular diseases owing, in part, to its established function in immune cell surveillance and trafficking. In this review, we highlight the role of the cardiac lymphatic system and its potential as an immunomodulatory therapeutic target in selected cardiovascular diseases., Competing Interests: Disclosures None.

Background: Stroke-induced heart syndrome is a feared complication of ischemic stroke, that is commonly encountered and has a strong association with unfavorable prognosis. More research is needed to explore underlying mechanisms and inform clinical decision making. This study aims to explore the relationship between the early systemic immune-inflammation (SII) index and the cardiac complications after acute ischemic stroke., Methods: Consecutive patients with acute ischemic stroke were prospectively collected from January 2020 to August 2022 and retrospectively analyzed. We included subjects who presented within 24 hours after symptom onset and were free of detectable infections or cancer on admission. SII index [(neutrophils × platelets/ lymphocytes)/1000] was calculated from laboratory data at admission., Results: A total of 121 patients were included in our study, of which 24 (19.8 %) developed cardiac complications within 14 days following acute ischemic stroke. The SII level was found higher in patients with stroke-heart syndrome (p<.001), which was an independent predictor of stroke-heart syndrome (adjusted odds ratio 5.089, p=.002)., Conclusion: New-onset cardiovascular complications diagnosed following a stroke are very common and are associated with early SII index., Competing Interests: Competing interests None., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: Sepsis remains a major source of morbidity and mortality in neonates, and characterization of immune regulation in the neonatal septic response remains limited. HVEM is a checkpoint regulator which can both stimulate or inhibit immune responses and demonstrates altered expression after sepsis. We hypothesized that signaling via HVEM would be essential for the neonatal response to sepsis, and that therefore blockade of this pathway would improve survival to septic challenge., Methods: To explore this, neonatal mice were treated with cecal slurry (CS), CS with Anti-HVEM antibody (CS-Ab) or CS with isotype (CS-IT) and followed for 7-day survival. Mice from all treatment groups had thymus, lung, kidney and peritoneal fluid harvested, weighed, and stained for histologic evaluation, and changes in cardiac function were assessed with echocardiography., Results: Mortality was significantly higher for CS-Ab mice (72.2%) than for CS-IT mice (22.2%). CS resulted in dysregulated alveolar remodeling, but CS-Ab lungs demonstrated significantly less dysfunctional alveolar remodeling than CS alone (MCL 121.0 CS vs. 87.6 CS-Ab), as well as increased renal tubular vacuolization. No morphologic differences in alveolar septation or thymic karyorrhexis were found between CS-Ab and CS-IT. CS-Ab pups exhibited a marked decrease in heart rate (390.3 Sh vs. 342.1 CS-Ab), stroke volume (13.08 CS-IT vs. 8.83 CS-Ab) and ultimately cardiac output (4.90 Sh vs. 3.02 CS-Ab) as well as a significant increase in ejection fraction (73.74 Sh vs. 83.75 CS-Ab) and cardiac strain (40.74 Sh vs. 51.16 CS-Ab) as compared to CS-IT or Sham animals., Discussion: While receptor ligation of aspects of HVEM signaling, via antibody blockade, appears to mitigate aspects of lung injury and thymic involution, stimulatory signaling via HVEM still seems to be necessary for vascular and hemodynamic resilience and overall neonatal mouse survival in response to this experimental polymicrobial septic insult. This dissonance in the activity of anti-HVEM neutralizing antibody in neonatal animals speaks to the differences in how septic cardiac dysfunction should be considered and approached in the neonatal population., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wakeley, Denning, Jiang, De Paepe, Chung, Wang and Ayala.)

Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Background: In recent years, the mechanistic interaction between the brain and heart has been explored in detail, which explains the effects of brain injuries on the heart and those of cardiac dysfunction on the brain. Brain injuries are the predominant cause of post-stroke deaths, and cardiac dysfunction is the second leading cause of mortality after stroke onset., Summary: Several studies have reported the association between brain injuries and cardiac dysfunction. Therefore, it is necessary to study the influence on the heart post-stroke to understand the underlying mechanisms of stroke and cardiac dysfunction. This review focuses on the mechanisms and the effects of cardiac dysfunction after the onset of stroke (ischemic or hemorrhagic stroke)., Key Messages: The role of the site of stroke and the underlying mechanisms of the brain-heart axis after stroke onset, including the hypothalamic-pituitary-adrenal axis, inflammatory and immune responses, brain-multi-organ axis, are discussed., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Inflammation and inflammasomes have been proposed as important regulators of the host-microorganism interaction, playing a key role in morbidity and mortality due to the coronavirus disease 2019 (COVID-19) in subjects with chronic conditions and compromised immune system. The inflammasome consists of a multiprotein complex that finely regulates the activation of caspase-1 and the production and secretion of potent pro-inflammatory cytokines such as IL-1β and IL-18. The pyrin containing NOD (nucleotide-binding oligomerization domain) like receptor (NLRP) is a family of intracellular receptors, sensing patterns associated to pathogens or danger signals and NLRP3 inflammasome is the most deeply analyzed for its involvement in the innate and adaptive immune system as well as its contribution to several autoinflammatory and autoimmune diseases. It is highly expressed in leukocytes and up-regulated in sentinel cells upon inflammatory stimuli. NLRP3 expression has also been reported in B and T lymphocytes, in epithelial cells of oral and genital mucosa, in specific parenchymal cells as cardiomyocytes, and keratinocytes, and chondrocytes. It is well known that a dysregulated activation of the inflammasome is involved in the pathogenesis of different disorders that share the common red line of inflammation in their pathogenetic fingerprint. Here, we review the potential roles of the NLRP3 inflammasome in cardiovascular events, liver damage, pulmonary diseases, and in that wide range of systemic inflammatory syndromes named as a cytokine storm.

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody, a dermatomyositis (DM)-specific antibody, is strongly associated with interstitial lung disease (ILD). Patients with idiopathic inflammatory myopathy (IIM) who are anti-MDA5 antibody positive [anti-MDA5 (+)] often experience chest symptoms during the active disease phase. These symptoms are primarily explained by respiratory failure; nevertheless, cardiac involvement can also be symptomatic. Thus, the aim of this study was to investigate cardiac involvement in anti-MDA5 (+) DM. A total of 63 patients with IIM who underwent electrocardiography (ECG) and ultrasound cardiography (UCG) during the active disease phase from 2016 to 2021 [anti-MDA5 (+) group, n = 21; anti-MDA5-negative (-) group, n = 42] were enrolled in the study, and their clinical charts were retrospectively reviewed. The ECG and UCG findings were compared between the anti-MDA5 (+) and anti-MDA5 (-) groups. All anti-MDA5 (+) patients had DM with ILD. The anti-MDA5 (+) group showed more frequent skin ulcerations and lower levels of leukocytes, muscle enzymes, and electrolytes (Na, K, Cl, and Ca) than the anti-MDA5 (-) group. According to the ECG findings obtained during the active disease phase, the T wave amplitudes were significantly lower for the anti-MDA5 (+) group than for the anti-MDA5 (-) group (I, II, and V4-6 lead; p < 0.01; aVF and V3, p < 0.05). However, the lower amplitudes were restored during the remission phase. Except for the E wave, A wave and Sep e', the UCG results showed no significant differences between the groups. Four patients with anti-MDA5 (+) DM had many leads with lower T wave and cardiac abnormalities (heart failure, diastolic dysfunction, myocarditis) on and after admission. Though anti-MDA5 (+) patients clinically improved after immunosuppressive therapy, some of their ECG findings did not fully recover in remission phase. In conclusion, anti-MDA5 (+) DM appears to show cardiac involvement (electrical activity and function) during the active phase. Further studies are necessary to clarify the actual cardiac condition and mechanism of these findings in patients with anti-MDA5 (+) DM., Competing Interests: RN has received research grants from Takeda and Medical & Biological Laboratories Co., Ltd., as well as speaker fees outside of the submitted work from Bristol Myers Squibb, Astellas Pharma Inc., Boehringer Ingelheim, Actelion Pharmaceuticals, and Mitsubishi Tanabe Pharma. HY has received a speaker fee from Boehringer Ingelheim. MT has received research grants and speaker fees from AbbVie GK, Asahi Kasei Pharma Corp., Astellas Pharma Inc., Ayumi Pharmaceutical Corp., Bristol Myers Squibb, Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., Pfizer Inc., UCB Japan Co., Ltd., Janssen Pharmaceutical K.K., Mitsubishi Tanabe Pharma Corp., Novartis Pharma K.K., and Taisho Pharma Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Matsuo, Sasai, Nakashima, Kuwabara, Kato, Murakami, Onizawa, Akizuki, Murakami, Hashimoto, Yoshifuji, Tanaka, Morinobu and Mimori.)

The mortality of sepsis-induced cardiac dysfunction (SICD) is very high due to the complex pathophysiological mechanism. Syringaresinol (SYR) is a natural abstract which possesses anti-inflammatory property. The present study aims was to identify the protective impact of SYR on sepsis-induced cardiac dysfunction and investigate the specific mechanisms. We found that SYR improved the cardiac function and alleviated myocardial injury in mice that subjected to cecal ligation and puncture, in addition, SIRT1 expression was significantly elevated after SYR treatment compared to sepsis group both in vivo and in vitro, along with suppression of NLRP3 activation and proinflammatory cytokines release. However, SIRT1 inhibitor EX427 abolished the impact of SYR on LPS-induced pyroptosis in cardiomyocytes. Furthermore, molecular docking analysis predicted that there is high affinity between SYR and estrogen receptor (ER), ER inhibitor ICI182780, the specific ERβ inhibitor PHTP and the specific ERαinhibitor AZD9496 were used to examine the role of ER in the protective effect of SYR against SICD, and the results suggested that ER activation was essential for the cardioprotective function of SYR. In conclusion, SYR ameliorates SICD via the ER/SIRT1/NLRP3/GSDMD pathway., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Viruses are an underappreciated cause of heart failure. Indeed, several types of viral infections carry cardiovascular risks. Understanding shared and unique mechanisms by which each virus compromises heart function is critical to inform on therapeutic interventions. This review describes how the key viruses known to lead to cardiac dysfunction operate. Both direct host-damaging mechanisms and indirect actions on the immune systems are discussed. As viral myocarditis is a key pathologic driver of heart failure in infected individuals, this review also highlights the role of cytokine storms and inflammation in virus-induced cardiomyopathy.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is commonly associated with myocardial injury and heart failure. The pathophysiology behind this phenomenon remains unclear, with many diverse and multifaceted hypotheses. To contribute to this understanding, we describe the underlying cardiac findings in fifty patients who died with coronavirus disease 2019 (COVID-19)., Methods: Included were autopsies performed on patients with a positive SARS-CoV-2 reverse-transcriptase-polymerase-chain reaction test from the index hospitalization. In the case of out-of-hospital death, patients were included if post-mortem testing was positive. Complete autopsies were performed according to a COVID-19 safety protocol, and all patients underwent both macroscopic and microscopic examination. If available, laboratory findings and echocardiograms were reported., Results: The median age of the decedents was 63.5 years. The most common comorbidities included hypertension (90.0%), diabetes (56.0%) and obesity (50.0%). Lymphocytic inflammatory infiltrates in the heart were present in eight (16.0%) patients, with focal myocarditis present in two (4.0%) patients. Acute myocardial ischemia was observed in eight (16.0%) patients. The most common findings were myocardial fibrosis (80.0%), hypertrophy (72.0%), and microthrombi (66.0%). The most common causes of death were COVID-19 pneumonia in 18 (36.0%), COVID-19 pneumonia with bacterial superinfection in 12 (24.0%), and COVID-19 pneumonia with pulmonary embolism in 10 (20.0%) patients., Conclusions: Cardiovascular comorbidities were prevalent, and pathologic changes associated with hypertensive and atherosclerotic cardiovascular disease were the most common findings. Despite markedly elevated inflammatory markers and cardiac enzymes, few patients exhibited inflammatory infiltrates or necrosis within cardiac myocytes. A unifying pathophysiologic mechanism behind myocardial injury in COVID-19 remains elusive, and additional autopsy studies are needed., (Copyright © 2021. Published by Elsevier Inc.)

Cerebral-cardiac syndrome (CCS) refers to cardiac dysfunction following varying brain injuries. Ischemic stroke is strongly evidenced to induce CCS characterizing as arrhythmia, myocardial damage, and heart failure. CCS is attributed to be the second leading cause of death in the post-stroke stage; however, the responsible mechanisms are obscure. Studies indicated the possible mechanisms including insular cortex injury, autonomic imbalance, catecholamine surge, immune response, and systemic inflammation. Of note, the characteristics of the stroke population reveal a common comorbidity with diabetes. The close and causative correlation of diabetes and stroke directs the involvement of diabetes in CCS. Nevertheless, the role of diabetes and its corresponding molecular mechanisms in CCS have not been clarified. Here we conclude the features of CCS and the potential role of diabetes in CCS. Diabetes drives establish a "primed" inflammatory microenvironment and further induces severe systemic inflammation after stroke. The boosted inflammation is suspected to provoke cardiac pathological changes and hence exacerbate CCS. Importantly, as the key element of inflammation, NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome is indicated to play an important role in diabetes, stroke, and the sequential CCS. Overall, we characterize the corresponding role of diabetes in CCS and speculate a link of NLRP3 inflammasome between them., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Lin, Li, Zhang, You, Xu, Liang and Zhang.)

Background Cardiac dysfunction is a prominent feature of multisystem inflammatory syndrome in children (MIS-C), yet the etiology is poorly understood. We determined whether dysfunction is global or regional, and whether it is associated with the cytokine milieu, microangiopathy, or severity of shock. Methods and Results We analyzed echocardiographic parameters of myocardial deformation and compared global and segmental left ventricular strain between 43 cases with MIS-C ≤18 years old and 40 controls. Primary outcomes included left ventricular global longitudinal strain, right ventricular free wall strain), and left atrial strain. We evaluated relationships between strain and profiles of 10 proinflammatory cytokines, microangiopathic features (soluble C5b9), and vasoactive-inotropic requirements. Compared with controls, cases with MIS-C had significant impairments in all parameters of systolic and diastolic function. 65% of cases with MIS-C had abnormal left ventricular function ( | global longitudinal strain | <17%), although elevations of cytokines were modest. All left ventricular segments were involved, without apical or basal dominance to suggest acute stress cardiomyopathy. Worse global longitudinal strain correlated with higher ratios of interleukin-6 (ρ -0.43) and interleukin-8 (ρ -0.43) to total hypercytokinemia, but not absolute levels of interleukin-6 or interleukin-8, or total hypercytokinemia. Similarly, worse right ventricular free wall strain correlated with higher relative interleukin-8 expression (ρ -0.59). There were no significant associations between function and microangiopathy or vasoactive-inotropic requirements. Conclusions Myocardial function is globally decreased in MIS-C and not explained by acute stress cardiomyopathy. Cardiac dysfunction may be driven by the relative skew of the immune response toward interleukin-6 and interleukin-8 pathways, more so than degree of hyperinflammation, refining the current paradigm of myocardial involvement in MIS-C.

In March 2020, the WHO declared coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a global pandemic. Obesity was soon identified as a risk factor for poor prognosis, with an increased risk of intensive care admissions and mechanical ventilation, but also of adverse cardiovascular events. Obesity is associated with adipose tissue, chronic low-grade inflammation, and immune dysregulation with hypertrophy and hyperplasia of adipocytes and overexpression of pro-inflammatory cytokines. However, to implement appropriate therapeutic strategies, exact mechanisms must be clarified. The role of white visceral adipose tissue, increased in individuals with obesity, seems important, as a viral reservoir for SARS-CoV-2 via angiotensin-converting enzyme 2 (ACE2) receptors. After infection of host cells, the activation of pro-inflammatory cytokines creates a setting conducive to the "cytokine storm" and macrophage activation syndrome associated with progression to acute respiratory distress syndrome. In obesity, systemic viral spread, entry, and prolonged viral shedding in already inflamed adipose tissue may spur immune responses and subsequent amplification of a cytokine cascade, causing worse outcomes. More precisely, visceral adipose tissue, more than subcutaneous fat, could predict intensive care admission; and lower density of epicardial adipose tissue (EAT) could be associated with worse outcome. EAT, an ectopic adipose tissue that surrounds the myocardium, could fuel COVID-19-induced cardiac injury and myocarditis, and extensive pneumopathy, by strong expression of inflammatory mediators that could diffuse paracrinally through the vascular wall. The purpose of this review is to ascertain what mechanisms may be involved in unfavorable prognosis among COVID-19 patients with obesity, especially cardiovascular events, emphasizing the harmful role of excess ectopic adipose tissue, particularly EAT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Lasbleiz, Gaborit, Soghomonian, Bartoli, Ancel, Jacquier and Dutour.)

Chronic inflammation, the activation of immune cells and their cross-talk with cardiomyocytes in the pathogenesis and progression of heart diseases has long been overlooked. However, with the latest research developments, it is increasingly accepted that a vicious cycle exists where cardiomyocytes release cardiocrine signaling molecules that spiral down to immune cell activation and chronic state of low-level inflammation. For example, cardiocrine molecules released from injured or stressed cardiomyocytes can stimulate macrophages, dendritic cells, neutrophils and even T-cells, which then subsequently increase cardiac inflammation by co-stimulation and positive feedback loops. One of the key proteins involved in stress-mediated cardiomyocyte signal transduction is a small GTPase RhoA. Importantly, the regulation of RhoA activation is critical for effective immune cell response and is being considered as one of the potential therapeutic targets in many immune-cell-mediated inflammatory diseases. In this review we provide an update on the role of RhoA at the juncture of immune cell activation, inflammation and cardiac disease.

In-depth characterization of heart-brain communication in critically ill patients with severe acute respiratory failure is attracting significant interest in the COronaVIrus Disease 19 (COVID-19) pandemic era during intensive care unit (ICU) stay and after ICU or hospital discharge. Emerging research has provided new insights into pathogenic role of the deregulation of the heart-brain axis (HBA), a bidirectional flow of information, in leading to severe multiorgan disease syndrome (MODS) in patients with confirmed infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Noteworthy, HBA dysfunction may worsen the outcome of the COVID-19 patients. In this review, we discuss the critical role HBA plays in both promoting and limiting MODS in COVID-19. We also highlight the role of HBA as new target for novel therapeutic strategies in COVID-19 in order to open new translational frontiers of care. This is a translational perspective from the Italian Society of Cardiovascular Researches., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Cardiac dysfunction is involved in disorders of energy metabolism. High-titre autoantibodies against the β 1 -adrenoceptor (β 1 -AAs) have been reported to exist in patients with cardiac dysfunction; however, the mechanism by which β 1 -AAs affect cardiac function is unknown. This study aimed to determine whether β 1 -AAs disturb myocardium energy metabolism and cause cardiac dysfunction. β 1 -AA monoclonal antibodies (β 1 -AAmAbs) were successfully pre-synthesized by hybridoma clones and used in all experiments. β 1 -AAmAbs impaired cardiac function and induced a myocardial metabolic disturbance, as evidenced by decreased left ventricular ejection fraction and fractional shortening. In addition, β 1 -AAmAbs decreased the adenosine triphosphate level and increased cardiac energy consumption (rate-pressure product). We further showed that the effects of β 1 -AAmAbs on heart tissue might involve the mitochondria and metabolic pathways via the β 1 -adrenoceptor based on an immunoprecipitation and mass spectrometry. Additionally, we found that β 1 -AAmAbs impaired myocardial mitochondrial structure, decreased the membrane potential, and induced insufficient mitophagy. In conclusion, β 1 -AAmAb-induced cardiac dysfunction is partly due to a disturbance in myocardial energy metabolism., (© 2021 John Wiley & Sons Australia, Ltd.)

Background: Inflammation can facilitate development of coronavirus disease 2019 (COVID-19) and cardiac injury is associated with worse clinical outcomes. However, data are relatively scarce on the association between hyper-inflammatory response and cardiac injury among COVID-19 patients., Methods: The study was designed based on severe and critically ill patients with COVID-19. Information on clinical characteristics and laboratory examinations was collected from the electronic medical records and analyzed., Results: There were 32.4% (n = 107) of patients with cardiac injury. The median age was 67 years, and 48.8% (n = 161) of patients were men. Hypertension was the most common in 161 (48.8%) patients, followed by diabetes (16.7%, n = 55) and coronary heart disease (13.3%, n = 44). Compared to cases without cardiac injury, those with cardiac injury were older, had higher proportions of coronary heart disease, and leukocyte counts, significantly elevated concentrations of N-terminal pro-B-Type natriuretic peptide, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor (TNF)-α, interleukin-2 receptor (IL-2R), IL-6, and IL-8, but lower lymphocyte counts. A significant positive correlation was observed between high-sensitivity troponin I and inflammatory cytokines. Logistic regression analysis showed that hs-CRP, TNF-α and IL-6 were independent risk factors for cardiac injury., Conclusions: Cardiac injury was associated with elevated levels of inflammatory cytokines among severe and critically ill patients with COVID-19, suggesting that hyper-inflammatory response may involve in cardiac injury., (Copyright © 2021 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

Sepsis-induced myocardial dysfunction (SIMD), a deadly symptom in sepsis patients, is mainly caused by cardiovascular inflammation. However, it remains unclear how systemic inflammation triggers and aggravates cardiovascular inflammation in the pathogenesis of SIMD. This study found that proinflammatory cytokines and H 2 O 2 concentrations were significantly induced in SIMD-mice. In particular, a microarray analysis of CD63 + exosomes isolated from sham- and SIMD-monocytes revealed a significant induction of thioredoxin-interacting protein (TXNIP) and NLR family pyrin domain-containing 3 (NLRP3). We proved that oxidative stress caused the disassociation of the TXNIP-TRX2 (thioredoxin 2) complex and the assembly of the TXNIP-NLRP3 complex. In addition, this finding showed that the latter complex could be embedded into CD63 + exosomes and traffic from monocytes to the resident heart macrophages, where it activated caspase-1 and cleaved inactive interleukin 1β (IL-1β) and IL-18. Furthermore, using an amplified luminescent proximity homogeneous assay (Alpha) with GST-TXNIP and His-NLRP3, we obtained a small molecule named PSSM1443 that could disrupt the TXNIP-NLRP3 interaction in vitro, impairing NLRP3 downstream events. Of note, after administering PSSM1443 to the SIMD-mice, we found the small molecule could significantly suppress the activation of caspase-1 and the cleavage of pro-IL-1β and pro-IL-18, reducing inflammation in the SIMD-mice. Collectively, our results reveal that monocyte-derived exosomes harbor the overexpressed TXNIP-NLRP3 complex, which traffics from circulating monocytes to local macrophages and promotes the cleavage of inactive IL-1β and IL-18 in the macrophages, aggravating cardiovascular inflammation. PSSM1443 functions as an inhibitor of the TXNIP-NLRP3 complex and its administration can decrease inflammation in SIMD-mice., (© 2021 Wiley Periodicals LLC.)

Background: A high proportion of COVID-19 patients have cardiac involvement, even those without known cardiac disease. Downregulation of angiotensin converting enzyme 2 (ACE2), a receptor for SARS-CoV-2 and the renin-angiotensin system, as well as inflammatory mechanisms have been suggested to play a role. ACE2 is abundant in the gut and associated with gut microbiota composition. We hypothesized that gut leakage of microbial products, and subsequent inflammasome activation could contribute to cardiac involvement in COVID-19 patients., Methods: Plasma levels of a gut leakage marker (LPS-binding protein, LBP), a marker of enterocyte damage (intestinal fatty acid binding protein, IFABP), a gut homing marker (CCL25, ligand for chemokine receptor CCR9) and markers of inflammasome activation (IL-1β, IL-18 and their regulatory proteins) were measured at three time points (day 1, 3-5 and 7-10) in 39 hospitalized COVID-19 patients and related to cardiac involvement., Results: Compared to controls, COVID-19 patients had elevated plasma levels of LBP and CCL25 but not IFABP, suggesting impaired gut barrier function and accentuated gut homing of T cells without excessive enterocyte damage. Levels of LBP were twice as high at baseline in patients with elevated cardiac markers compared with those without and remained elevated during hospitalization. Also, markers of inflammasome activation were moderately elevated in patients with cardiac involvement. LBP was associated with higher NT-pro-BNP levels, whereas IL-18, IL-18BP and IL-1Ra were associated with higher troponin levels., Conclusion: Patients with cardiac involvement had elevated markers of gut leakage and inflammasome activation, suggestive of a potential gut-heart axis in COVID-19., (© 2020 The Authors. Journal of Internal Medicine published by John Wiley & Sons Ltd on behalf of Association for Publication The Journal of Internal Medicine.)

Dendritic cell-associated C-type lectin-1 (Dectin-1), also known as β-glucan receptor is an emerging pattern recognition receptor (PRR) which belongs to the family of C-type lectin receptor (CLR). This CLR identifies ligands independently of Ca 2+ and is majorly involved in coupling of innate with adaptive immunity. Formerly, Dectin-1 was best known for its role in anti-fungal defense only. However, recent explorations suggested its wider role in defense against variety of infectious diseases caused by pathogens including bacteria, parasites and viruses. In fact, Dectin-1 signaling axis has been suggested to be targeted as an effective therapeutic strategy for cancers. Dectin-1 has also been elucidated ascetically in the heart, respiratory, intestinal, neurological and developmental disorders. Being a defensive PRR, Dectin-1 results in optimal immune responses in collaboration with other PRRs, but the overall evaluation reinforces the hypothesis of disease development on dis-regulation of Dectin-1 activity. This underscores the impact of Dectin-1 polymorphisms in modulating protein expression and generation of non-optimal immune responses through defective collaborations, further underlining their therapeutic potential. To add on, Dectin-1 influence autoimmunity and severe inflammation accredited to recognition of self T cells and apoptotic cells through unknown ligands. Few reports have also testified its redundant role in infections, which makes it a complicated molecule to be fully resolved. Thus, Dectin-1 is a hub that runs a complex collaborative network, whose interactive wire connections to different PRRs are still pending to be revealed. Alternatively, so far focus of almost all the researchers was the two major cell surface isoforms of Dectin-1, despite the fact that its soluble functional intracellular isoform (Dectin-1E) has already been dissected but is indefinable. Therefore, this review intensely recommends the need of future research to resolve the un-resolved and treasure the comprehensive role of Dectin-1 in different clinical outcomes, before determining its therapeutic prospective., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Background: Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic. The ability to predict cardiac injury and analyze lymphocyte immunity and inflammation of cardiac damage in patients with COVID-19 is limited. We aimed to determine the risk factors and predictive markers of cardiac injury in these patients., Methods: Data from 124 consecutive hospitalized patients with confirmed COVID-19 were collected. We compared the proportion of cardiovascular disease history in moderate, severe, and critical cases. We obtained high-sensitivity cardiac troponin I (hs-cTn I) results from 68 patients. Patients were divided into two groups based on positive hs-cTn I result: those with cardiac injury (n = 19) and those without cardiac injury (n = 49)., Results: Compared with the group with moderate disease, hypertension, coronary heart disease, and smoking were more common in severe and critical cases. Diabetes mellitus was most common in the critical group. Age older than 65 years, presence of chronic kidney disease, and lower blood lymphocyte percentage were independent risk factors of cardiac injury. The total T- and B-lymphocyte counts and CD4+ and CD8+ T-cell counts were significantly lower in those with cardiac injury. A minimal lymphocyte percentage < 7.8% may predict cardiac injury. The interleukin (IL) 6 level in plasma was elevated in the group with cardiac injury., Conclusions: The lymphocyte percentage in blood may become a predictive marker of cardiac injury in COVID-19 patients. The total T and B cells and CD4+ and CD8+ cell counts decreased and the IL-6 level increased in COVID-19 patients with cardiac injury., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020. Published by Elsevier B.V.)

The most striking consequence of a heart attack is the loss of billions of heart muscle cells, alongside damage to the associated vasculature. The lost cardiovascular tissue is replaced by scar formation, which is non-functional and results in pathological remodelling of the heart and ultimately heart failure. It is, therefore, unsurprising that the heart regeneration field has centred efforts to generate new muscle and blood vessels through targeting cardiomyocyte proliferation and angiogenesis following injury. However, combined insights from embryological studies and regenerative models, alongside the adoption of -omics technology, highlight the extensive heterogeneity of cell types within the forming or re-forming heart and the significant crosstalk arising from non-muscle and non-vessel cells. In this review, we focus on the roles of fibroblasts, immune, conduction system, and nervous system cell populations during heart development and we consider the latest evidence supporting a function for these diverse lineages in contributing to regeneration following heart injury. We suggest that the emerging picture of neurologically, immunologically, and electrically coupled cell function calls for a wider-ranging combinatorial approach to heart regeneration., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

The cardiovascular and immune systems undergo profound and intertwined alterations with aging. Recent studies have reported that an accumulation of memory and terminally differentiated T cells in elderly subjects can fuel myocardial aging and boost the progression of heart diseases. Nevertheless, it remains unclear whether the immunological senescence profile is sufficient to cause age-related cardiac deterioration or merely acts as an amplifier of previous tissue-intrinsic damage. Herein, we sought to decompose the causality in this cardio-immune crosstalk by studying young mice harboring a senescent-like expanded CD4 + T cell compartment. Thus, immunodeficient NSG-DR1 mice expressing HLA-DRB1*01:01 were transplanted with human CD4 + T cells purified from matching donors that rapidly engrafted and expanded in the recipients without causing xenograft reactions. In the donor subjects, the CD4 + T cell compartment was primarily composed of naïve cells defined as CCR7 + CD45RO - . However, when transplanted into young lymphocyte-deficient mice, CD4 + T cells underwent homeostatic expansion, upregulated expression of PD-1 receptor and strongly shifted towards effector/memory (CCR7 - CD45RO + ) and terminally-differentiated phenotypes (CCR7 - CD45RO - ), as typically seen in elderly. Differentiated CD4 + T cells also infiltrated the myocardium of recipient mice at comparable levels to what is observed during physiological aging. In addition, young mice harboring an expanded CD4 + T cell compartment showed increased numbers of infiltrating monocytes, macrophages and dendritic cells in the heart. Bulk mRNA sequencing analyses further confirmed that expanding T-cells promote myocardial inflammaging, marked by a distinct age-related transcriptomic signature. Altogether, these data indicate that exaggerated CD4 + T-cell expansion and differentiation, a hallmark of the aging immune system, is sufficient to promote myocardial alterations compatible with inflammaging in juvenile healthy mice., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Delgobo, Heinrichs, Hapke, Ashour, Appel, Srivastava, Heckel, Spyridopoulos, Hofmann, Frantz and Ramos.)

Doxorubicin (DOX) is a powerful broad-spectrum anti-neoplastic anthracycline antibiotic. However, DOX may cause a dose-dependent cardiotoxicity that can eventually progress to congestive heart failure and death. Numerous molecular mechanisms have been implicated in the cardiotoxic effect of DOX including topoisomerase IIβ and generation of free radicals. However, targeting these pathways appears to be insufficient to mitigate the cardiotoxic effects of DOX and/or ultimately reduces the anti-tumor activity of DOX. Thus, there remains a crucial need to identify novel pharmacological targets that can alleviate the cardiotoxic effects of DOX without reducing its anti-tumor activity. Recent studies have suggested that the Nucleotide-Binding Domain-Like Receptor Protein 3 (NLRP3) inflammasome is implicated in tumor progression and the chemoresistance of cancer cells to DOX. Of interest, reducing NLRP3 inflammasome activity alleviates DOX-induced cardiotoxicity. Therefore, we postulate that strategies that target the NLRP3 inflammasome can help mitigate the cardiotoxic effects of DOX while maintaining and/or even enhancing its anti-cancer activity. Herein, we review the current knowledge about the potential implication of the NLRP3 inflammasome in the anti-cancer and cardiotoxic effects of DOX.

Abstract: Chagas disease affects approximately 7 million people, causing disability and mortality in the most productive life stages of infected individuals. Considering the lifestyle of the world population, metabolic syndrome is a synergistic factor for an increased cardiovascular risk of patients with Chagas disease.This study transversally evaluated the metabolic and immunological profiles of patients with indeterminate (IF) and cardiac (CF) forms of Chagas disease and their correlations with left ventricular dysfunction (LVD).Clinical and electrical bioimpedance analysis, levels of cytokines (interferon [IFN]-γ, tumor necrosis factor [TNF]-α, interleukin [IL]-17, IL-10, and IL-33) and adipocytokines (adiponectin, leptin, and resistin), metabolic syndrome components, and brain natriuretic peptide (BNP) levels were assessed in 57 patients (13 IF and 44 CF) with a mean age of 61.63 ± 12.1 years. Chest x-ray, electrocardiogram, and echocardiogram were performed to classify the clinical forms.The CF group had a higher number of individuals with metabolic syndrome components blood pressure altered, while more participants in the CF group with LVD had low high-density lipoprotein (HDL) levels. The IF group had more participants with a higher waist-to-hip ratio (WHR). No significant difference was observed between metabolic syndrome, cytokine and adipocytokine level, and clinical forms of the disease or in relation to LVD.Individuals with the IF showed metabolic and immunological profiles compatible with increased disease control, whereas those with CF showed marked inflammatory immune response., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2020 the Author(s). Published by Wolters Kluwer Health, Inc.)

Resident cardiac macrophages (rcMacs) are integral components of the myocardium where they have key roles for tissue homeostasis and in response to inflammation, tissue injury and remodelling. In this review, we summarize the current knowledge and limitations associated with the rcMacs studies. We describe their specific role and contribution in various processes such as electrical conduction, efferocytosis, inflammation, tissue development, remodelling and regeneration in both the healthy and the disease state. We also outline research challenges and technical complications associated with rcMac research. Recent technological developments and contemporary immunological techniques are now offering new opportunities to investigate the separate contribution of rcMac in respect to recruited monocytes and other cardiac cells. Finally, we discuss new therapeutic strategies, such as drugs or non-coding RNAs, which can influence rcMac phenotype and their response to inflammation. These novel approaches will allow for a deeper understanding of this cardiac endogenous cell type and might lead to the development of more specific and effective therapeutic strategies to boost the heart's intrinsic reparative capacity.

Coronavirus disease 2019 (COVID-19) patients with pre-existing cardiovascular disease (CVD) or with cardiovascular complications have a higher risk of mortality. The main cardiovascular complications of COVID-19 include acute cardiac injury, acute myocardial infarction (AMI), myocarditis, arrhythmia, heart failure, shock, and venous thromboembolism (VTE)/pulmonary embolism (PE). COVID-19 can cause cardiovascular complications or deterioration of coexisting CVD through direct or indirect mechanisms, including viral toxicity, dysregulation of the renin-angiotensin-aldosterone system (RAAS), endothelial cell damage and thromboinflammation, cytokine storm, and oxygen supply-demand mismatch. We systematically review cardiovascular manifestations, histopathology, and mechanisms of COVID-19, to help to formulate future research goals and facilitate the development of therapeutic management strategies., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Cardiac injury may have multiple causes, including ischaemic, non-ischaemic, autoimmune, and infectious triggers. Independent of the underlying pathophysiology, cardiac tissue damage induces an inflammatory response to initiate repair processes. Immune cells are recruited to the heart to remove dead cardiomyocytes, which is essential for cardiac healing. Insufficient clearance of dying cardiomyocytes after myocardial infarction (MI) has been shown to promote unfavourable cardiac remodelling, which may result in heart failure (HF). Although immune cells are integral key players of cardiac healing, an unbalanced or unresolved immune reaction aggravates tissue damage that triggers maladaptive remodelling and HF. Neutrophils and macrophages are involved in both, inflammatory as well as reparative processes. Stimulating the resolution of cardiac inflammation seems to be an attractive therapeutic strategy to prevent adverse remodelling. Along with numerous experimental studies, the promising outcomes from recent clinical trials testing canakinumab or colchicine in patients with MI are boosting the interest in novel therapies targeting inflammation in cardiovascular disease patients. The aim of this review is to discuss recent experimental studies that provide new insights into the signalling pathways and local regulators within the cardiac microenvironment promoting the resolution of inflammation and tissue regeneration. We will cover ischaemia- and non-ischaemic-induced as well as infection-related cardiac remodelling and address potential targets to prevent adverse cardiac remodelling., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Cardiac allograft vasculopathy (CAV)-mediated by a heterogeneous myriad of immune and non-immune factors, which contribute to the progressive and diffuse thickening of the arterial allograft's tunica intima in one distinct form of CAV, and the build-up of plaque in another-is a major limiting factor of long-term survival post heart transplantation. Information on the optimal pharmacotherapeutic approaches for the prevention and management of CAV is conflicting, scattered, and inconsistent, with numerous recent studies adding to the literature. In this paper, we present a go-to clinical resource with the most updated and comprehensive information on the topic. Immunosuppressant therapy remains a staple, with mTOR inhibitors and mycophenolate mofetil (MMF) showing direct correlation with CAV prevention. More data is now available with calcineurin inhibitor (CNI) minimizing or sparing regimens. More novel approaches are being investigated for the roles of monoclonal antibodies, anti-thymocyte globulin, and bortezomib in preventing or delaying CAV. On the other hand, statins' established efficacy is attributed to lipid-lowering and lipid-independent immunomodulatory effects, with early initiation associated with improved outcomes. The choice of statin is dependent on drug-drug interactions. Other aiding approaches for the prevention of CAV include antioxidant vitamins, aspirin, vasodilators, folate therapy, and, most pertinently, cytomegalovirus prophylaxis. Larger clinical trials are needed before these options are institutionalised. For management of established CAV, early initiation of augmented immunosuppressive therapies may be effective, as well as CNI conversion to mTOR inhibitors with or without standard MMF and azathioprine therapy. Risk of acute rejection needs to be monitored during conversion. Finally, preclinical investigations highlight novel potential therapies for CAV prevention and attenuation, however robust clinical trials are needed to test their efficacy and safety., Competing Interests: Declaration of competing interest MRM is a consultant for Abbott (fees paid to Brigham and Women's Hospital), Portola, Bayer, Baim Institute for Clinical Research and Triple Gene; a trial steering committee member for Medtronic and Janssen; a scientific advisory board member for Leviticus, NupulseCV and FineHeart; and a DSMB member for Mesoblast. Other authors have no pertinent disclosures., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose of Review: Coronavirus disease of 2019 (COVID-19) is a cause of significant morbidity and mortality worldwide. While cardiac injury has been demonstrated in critically ill COVID-19 patients, the mechanism of injury remains unclear. Here, we review our current knowledge of the biology of SARS-CoV-2 and the potential mechanisms of myocardial injury due to viral toxicities and host immune responses., Recent Findings: A number of studies have reported an epidemiological association between history of cardiac disease and worsened outcome during COVID infection. Development of new onset myocardial injury during COVID-19 also increases mortality. While limited data exist, potential mechanisms of cardiac injury include direct viral entry through the angiotensin-converting enzyme 2 (ACE2) receptor and toxicity in host cells, hypoxia-related myocyte injury, and immune-mediated cytokine release syndrome. Potential treatments for reducing viral infection and excessive immune responses are also discussed. COVID patients with cardiac disease history or acquire new cardiac injury are at an increased risk for in-hospital morbidity and mortality. More studies are needed to address the mechanism of cardiotoxicity and the treatments that can minimize permanent damage to the cardiovascular system.

Epidemiologic studies show that the levels of air pollutants and particulate matter are positively associated with the morbidity and mortality of cardiovascular diseases. Here we demonstrate that the intratracheal instillation of multi-walled carbon nanotubes (MWCNTs), a standard fine particle, exacerbate doxorubicin (DOX)-induced cardiotoxicity in mice through altering gut microbiota and pulmonary and colonic macrophage phenotype. MWCNTs (25 μg/kg per day, 5 days a week for 3 weeks) promoted cardiotoxicity and apoptosis in the DOX (2 mg/kg, twice a week for 5 weeks)-treated C57BL/6 mice. MWCNTs exaggerated DOX-induced gut microbiota dysbiosis characterized by the increased abundances of Helicobacteraceae and Coriobacteriaceae. In addition, MWCNTs promoted DOX-induced M1-like polarization of colonic macrophages with an increase in TNF-α, IL-1β and CC chemokine ligand 2 in peripheral blood. Importantly, treatment with the antibiotics attenuated MWCNTs plus DOX-induced apoptosis of cardiomyocytes and M1-like polarization of colonic macrophages. The fecal microbiota transplantation demonstrated that MWCNTs exaggerated DOX-induced cardiotoxicity with M1-like polarization of colonic macrophages. The conditioned medium from MWCNTs-treated pulmonary macrophages promoted DOX-induced gut microbiota dysbiosis and colonic macrophage polarization. Furthermore, the co-culture of macrophages and fecal bacteria promoted M1-like macrophage polarization and their production of TNF-α and IL-1β, and thereby exacerbated the effects of MWCNTs. Moreover, IL-1β and TNF-α blockade, either alone or in combination attenuated MWCNTs-exacerbated cardiotoxicity. In summary, MWCNTs exacerbate DOX-induced cardiotoxicity in mice through gut microbiota and pulmonary and colonic macrophage interaction. Our findings identify a novel mechanism of action of inhaled particle-driven cardiotoxicity., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: Red blood cell autoantibodies (RBC autoAbs) of IgG class are found in the majority of patients with warm autoimmune hemolytic anemia (wAIHA) but sometimes also during the pretransfusion testing of patients with different diagnoses but without hemolysis. The aim of the study was to identify the main differences between these two groups of patients according to age, gender, subclass and titer of IgG RBC autoAbs and diagnosis., Material and Methods: In the 9-year retrospective study, data were collected from records of 291 patients with IgG RBC autoAbs detected by gel technique, from which 111 with wAIHA., Results: More than 85% of patients in both groups were over 40 years old, with male to female ratio 1:1.9 in wAIHA vs 1:1.3 in patients without hemolysis (P=0.0916). The main characteristics of patients with wAIHA vs patients without hemolysis were: IgG only 38% vs 70%, IgG+Complement 62% vs 30%, total IgG1 79% vs 55%, IgG1+IgG3 35% vs 11%, titer of 100 for IgG1+IgG3 17% vs 3% (P<0.0001), respectively, while titer of 100 for IgG1 18% vs 9% (P=0.0241). The underlying diagnosis in wAIHA vs patients without hemolysis: hematologic disorders 41% vs 22% (P=0.0006), autoimmune disorders 12% vs 13% (P=0.8033), solid tumors 5% vs 14% (P=0.0154) and surgery procedures 6% vs 26% (P<0.0001)., Conclusion: We observed more wAIHA patients with high titer of IgG1 and high prevalence of IgG1+IgG3 and consider that patients without hemolysis having identical results might be interesting to find out how they are protected from damage by RBC autoAbs., (Copyright © 2019 Société française de transfusion sanguine (SFTS). Published by Elsevier Masson SAS. All rights reserved.)

The SOD3 variant, SOD3R213G, results from substitution of arginine to glycine at amino acid 213 (R213G) in its heparin binding domain (HBD) and is a common genetic variant, reported to be associated with ischemic heart disease. However, little is understood about the role of SOD3R213G in innate immune function, and how it leads to dysfunction of the cardiovascular system. We observed pathologic changes in SOD3R213G transgenic (Tg) mice, including cystic medial degeneration of the aorta, heart inflammation, and increased circulating and organ infiltrating neutrophils. Interestingly, SOD3R213G altered the profile of SOD3 interacting proteins in neutrophils in response to G-CSF. Unexpectedly, we found that G-CSF mediated tyrosine phosphatase, SH-PTP1 was down-regulated in the neutrophils of SOD3R213G overexpressing mice. These effects were recovered by reconstitution with Wt SOD3 expressing bone marrow cells. Overall, our study reveals that SOD3R213G plays a crucial role in the function of the cardiovascular system by controlling innate immune response and signaling. These results suggest that reconstitution with SOD3 expressing bone marrow cells may be a therapeutic strategy to treat SOD3R213G mediated diseases., Competing Interests: The authors have declared that no competing interests exist.

Macrophages are one cell type in the innate immune system. Recent studies involving macrophages have overturned the conventional concept that circulating bone marrow-derived blood mononuclear cells in the adult body continuously replace macrophages residing in the tissues. Investigations using refined technologies have suggested that embryonic hematopoiesis can result in the differentiation into macrophage subgroups in some tissues. In adulthood, these macrophages are self-sustaining via in situ proliferation, with little contribution of circulating bone marrow-derived blood mononuclear cells. Macrophages are integral component of the heart, accounting for 8% of the non-cardiac cells. The use of innovative molecular techniques in paradigm shifting researches has revealed the complexity of cardiac macrophages, including their heterogeneity and ontological diversity. Resident cardiac macrophages modulate the physiological and pathophysiological processes of the cardiovascular system, with distinct and crucial roles in healthy and injured hearts. Their functions include sensing of pathogens, antigen presentation, digesting cell debris, regulating inflammatory responses, generating distinct cytokines, and secreting some regulatory factors. More recent studies have revealed further functions of cardiac macrophages. This review focuses on macrophages within the cardiovascular system. We discuss evidence that has changed our collective view of cardiac macrophage subgroups, and improved our understanding of the different phenotypes, cell surface markers, heterogeneities, origins, developments, and the dynamic and separate roles of these cardiac macrophage subgroups in the steady state and injured hearts. This review may provide novel insights concerning the pathophysiology of cardiac-resident macrophages in cardiovascular diseases and innovative therapeutic strategies that could include the modulation of the role of macrophages in cardiovascular injuries.

There is substantial evidence that chronic heart failure in humans and in animal models is associated with inflammation. Ischemic interventions such as myocardial infarction lead to necrotic cell death and release of damage associated molecular patterns, factors that signal cell damage and induce expression of proinflammatory chemokines and cytokines. It has recently become evident that nonischemic interventions are also associated with increases in inflammatory genes and immune cell accumulation in the heart and that these contribute to fibrosis and ventricular dysfunction. How proinflammatory responses are elicited in nonischemic heart disease which is not, at least initially, associated with cell death is a critical unanswered question. In this review we provide evidence supporting the hypothesis that cardiomyocytes are an initiating site of inflammatory gene expression in response to nonischemic stress. Furthermore we discuss the role of the multifunctional Ca 2+ /calmodulin-regulated kinase, CaMKIIδ, as a transducer of stress signals to nuclear factor-κB activation, expression of proinflammatory cytokines and chemokines, and priming and activation of the NOD-like pyrin domain-containing protein 3 (NLRP3) inflammasome in cardiomyocytes. We summarize recent evidence that subsequent macrophage recruitment, fibrosis and contractile dysfunction induced by angiotensin II infusion or transverse aortic constriction are ameliorated by blockade of CaMKII, of monocyte chemoattractant protein-1/C-C chemokine receptor type 2 signaling, or of NLRP3 inflammasome activation.

The advent of immunotherapy, particularly immune checkpoint inhibitors and chimeric antigen receptor T-cell therapy, has ushered in a promising new era of treatment of patients with a variety of malignancies who historically had a poor prognosis. However, these therapies are associated with potentially life-threatening cardiovascular adverse effects. As immunotherapy evolves to include a wider variety of malignancies, risk stratification, prompt recognition, and treatment of cardiotoxicity will become increasingly important and hence cardiologists will need to play a fundamental role in the comprehensive care of these patients. This article reviews cardiotoxicity associated with contemporary immunotherapy and discusses potential management strategies., (Copyright © 2019 Elsevier Inc. All rights reserved.)