Abstract
Cauterization of the root of the left coronary artery (LCA) in the neonatal heart at postnatal day 1 (P1) resulted in large reproducible lesions of the left ventricle (LV), and an attendant marked adaptive response in the right ventricle (RV). The response of both chambers to LV myocardial infarction involved enhanced cardiomyocyte (CM) division and binucleation, as well as LV re-vascularization, leading to restored heart function within 7 days post-surgery (7 dps). By contrast, infarction of P3 mice resulted in cardiac scarring without a significant regenerative and adaptive response of the LV and the RV leading to subsequent heart failure and death within 7 dps. The prominent RV myocyte expansion in P1 mice involved an acute increase in pulmonary arterial pressure and a unique gene regulatory response, leading to an increase in RV mass and preserved heart function. Thus, distinct adaptive mechanisms in the RV, such as CM proliferation and RV expansion, enable marked cardiac regeneration of the infarcted LV at P1 and full functional recovery.
Authors
Tianyuan Hu, Mona Malek Mohammadi, Fabian Ebach, Michael Hesse, Michael I. Kotlikoff, Bernd K. Fleischmann
Abstract
A robust sterile inflammation underlies myocardial ischemia and reperfusion injury (MIRI). Several subsets of B-cells possess the immune-regulatory capacity that limits tissue damage, yet the role of B-cells in MIRI remains elusive. Here, we sought to elucidate the contribution of B-cells to the MIRI by transient ligation of the left anterior descending in the B-cell depleted or deficient mice. Following ischemia and reperfusion (I/R), regulatory B-cells are rapidly recruited to the heart. B-cell-depleted or deficient mice exhibited exacerbated tissue damage, adverse cardiac remodeling, and an augmented inflammatory response after I/R. Rescue and chimeric experiments indicated that the cardioprotective effect of B-cells was not solely dependent on IL10. Coculture experiments demonstrated that B-cells induced neutrophil apoptosis through contact-dependent interaction, subsequently promoting reparative macrophage polarization by facilitating the phagocytosis of neutrophils by macrophages. The in-vivo cardioprotective effect of B-cells was absent in absence of neutrophils after I/R. Mechanistically, ligand-receptor imputation identified FCER2A as a potential mediator of interactions between B-cells and neutrophils. Blocking FCER2A on B-cells resulted in a reduction in the percentage of apoptotic neutrophils, contributing to the deterioration of cardiac remodeling. Our findings unveil a potential cardioprotective role of B-cells in myocardial I/R through mechanisms involving FCER2A, neutrophil, and macrophage.
Authors
Fangyang Huang, Jialiang Zhang, Hao Zhou, Tianyi Qu, Yan Wang, Kexin Jiang, Yutong Liu, Yuan Ning Xu, Mao Chen, Li Chen
Abstract
The impairment of left ventricular (LV) diastolic function with inadequate increase in myocardial relaxation velocity directly results in lower LV compliance, increased LV filling pressures and heart failure symptoms. The development of agents facilitating the relaxation of human cardiomyocytes requires a better understanding of the underlying regulatory mechanisms. We performed a high-content microscopy-based screening in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) using a library of 2565 human miRNA mimics and measured relaxation kinetics via high-computing analyses of motion movies. We identified hsa-miR-548v, a primate specific miRNA, as the miRNA producing the largest increase in relaxation velocities. This positive lusitropic effect was reproduced in engineered cardiac tissues generated with healthy and BRAF T599R mutant hiPSC-CMs, and was independent of changes in calcium transients. Consistent with improvements in viscoelastic responses to mechanical stretch, RNA-sequencing showed that hsa-miR-548v down-regulated multiple targets, especially components of the mechano-sensing machinery. The exogenous administration of hsa-miR-548v in hiPSC-CMs notably resulted in a significant reduction of ANKRD1/CARP1 expression and localization at the sarcomeric I-band. This study suggests that the sarcomere I-band is a critical control center of the ability of cardiomyocytes to relax and a target for improving relaxation and diastolic dysfunction.
Authors
Eva Vermersch, Salomé Neuvendel, Charlene Jouve, Andrea Ruiz-Velasco, Céline Pereira, Magali Seguret, Marie-Elodie Cattin-Messaoudi, Sofia Lotfi, Thierry Dorval, Pascal Berson, Jean-Sébastien Hulot
Abstract
There is great interest in identifying signaling pathways that promote cardiac repair after myocardial infarction (MI). Prior studies suggest a beneficial role for IL13 signaling in neonatal heart regeneration, however, the cell types mediating cardiac regeneration and the extent of IL13 signaling in the adult heart post-injury are unknown. We identified an abundant source of IL13 and the related cytokine, IL4, in neonatal cardiac type 2 innate lymphoid cells (ILC2s), however, ILC2 production of IL13 and IL4 as well as ILC2 frequency declined precipitously in adult hearts. In agreement with this finding, IL13 receptor deletion in macrophages impaired cardiac function and delayed scar clearance after neonatal MI. By using a combination of recombinant IL13 (rIL13) administration and cell-specific IL13 receptor genetic deletion models we found that IL13 signaling specifically to macrophages significantly promotes cardiac functional recovery after MI in adult mice. Single cell RNA sequencing revealed a sub-population of macrophages appearing in the heart early after injury only in response to rIL13 administration. These IL13 induced macrophages are independent of classically defined alternatively activated macrophages, are highly efferocytotic and can be identified in vivo by expression of IL1R2. IL1R2+ macrophages are induced upon rIL13 administration in adult mice and depend on IL13 signaling directly to macrophages. Collectively, we elucidate a strongly pro-reparative role for IL13 signaling directly to macrophages following cardiac injury. While this pathway is active in pro-regenerative neonatal stages, re-activation of macrophage IL13 signaling is required to promote cardiac functional recovery in adults.
Authors
Santiago Alvarez-Argote, Samantha J. Paddock, Michael A. Flinn, Caelan W. Moreno, Makenna C. Knas, Victor A. Almeida, Sydney L. Buday, Amirala Bakhshian Nik, Michaela Patterson, Yi-Guang Chen, Chien-Wei Lin, Caitlin C. O'Meara
Abstract
Three-dimensional engineered cardiac tissue (ECT) using purified human induced pluripotent stem cell–derived cardiomyocytes (hiPSC-CMs) has emerged as an appealing model system for the study of human cardiac biology and disease. A recent study reported widely-used metabolic (lactate) purification of monolayer hiPSC-CM cultures results in an ischemic cardiomyopathy-like phenotype compared to magnetic antibody-based cell sorting (MACS) purification, complicating the interpretation of studies using lactate-purified hiPSC-CMs. Herein, our objective was to determine if use of lactate relative to MACS-purified hiPSC-CMs impacts the properties of resulting hiPSC-ECTs. Therefore, hiPSC-CMs were differentiated and purified using either lactate-based media or MACS. Global proteomics revealed lactate-purified hiPSC-CMs displayed a differential phenotype over MACS hiPSC-CMs. hiPSC-CMs were then integrated into 3D hiPSC-ECTs and cultured for four weeks. Structurally, there was no significant difference in sarcomere length between lactate and MACS hiPSC-ECTs. Assessment of isometric twitch force and Ca2+ transients measurements revealed similar functional performance between purification methods. High-resolution mass spectrometry (MS)-based quantitative proteomics showed no significant difference in protein pathway expression or myofilament proteoforms. Taken together, this study demonstrates lactate- and MACS-purified hiPSC-CMs generate ECTs with comparable structural, functional, and proteomic features, and suggests lactate purification does not result in an irreversible change in hiPSC-CM phenotype.
Authors
Kalina J. Rossler, Willem J. De Lange, Morgan W. Mann, Timothy J. Aballo, Jake A. Melby, Jianhua Zhang, Gina Kim, Elizabeth F. Bayne, Yanlong Zhu, Emily T. Farrell, Timothy J. Kamp, J. Carter Ralphe, Ying Ge
Abstract
Ventricular arrhythmias (VAs) in heart failure are enhanced by sympathoexcitation. However, radiotracer studies of catecholamine uptake in failing human hearts demonstrate a proclivity for VAs in patients with reduced cardiac sympathetic innervation. We hypothesized that this counterintuitive finding is explained by heterogeneous loss of sympathetic nerves in the failing heart. In a murine model of dilated cardiomyopathy (DCM), delayed PET imaging of sympathetic nerve density using the catecholamine analog [11C]meta-Hydroxyephedrine ([11C]-mHED) demonstrated global hypoinnervation in ventricular myocardium. Although reduced, sympathetic innervation in two distinct DCM models invariably exhibited transmural (epicardial to endocardial) gradients, with the endocardium being devoid of sympathetic nerve fibers vs. controls. Further, the severity of transmural innervation gradients was correlated with VAs (r = 0.6, P < 0.05). Transmural innervation gradients were also identified in human left ventricular free wall samples from DCM vs controls. We investigated mechanisms underlying this relationship by in silico studies in 1-D, 2-D, and 3-D models of failing and normal human hearts, finding that arrhythmogenesis increased as heterogeneity in sympathetic innervation worsened. Specifically, both DCM-induced myocyte electrical remodeling and spatially inhomogeneous innervation gradients synergistically worsened arrhythmogenesis. Thus, heterogeneous innervation gradients in DCM promoted arrhythmogenesis. Restoration of homogeneous sympathetic innervation in the failing heart may reduce VAs.
Authors
Al-Hassan J. Dajani, Michael B. Liu, Michael A. Olaopa, Lucian Cao, Carla Valenzuela Ripoll, Timothy J. Davis, Megan D. Poston, Elizabeth H. Smith, Jaime Contreras, Marissa Pennino, Christopher M. Waldmann, Donald B. Hoover, Jason T. Lee, Patrick Y. Jay, Ali Javaheri, Roger Slavik, Zhilin Qu, Olujimi A. Ajijola
Abstract
Background: Cardiorenal syndrome (CRS)—renal injury during heart failure (HF)—is linked to higher morbidity. Whether circulating extracellular vesicles (EVs) and their RNA cargo directly impact its pathogenesis remains unclear. Methods: We investigated the role of circulating EVs from patients with CRS on renal epithelial/endothelial cells using a microfluidic kidney-on-chip model (KOC). The small RNA cargo of circulating EVs was regressed against serum creatinine to prioritize subsets of functionally relevant EV miRNAs and their mRNA targets investigated using in silico pathway analysis, human genetics, and interrogation of expression in the KOC model and in renal tissue. The functional effects of EV-RNAs on kidney epithelial cells were experimentally validated.Results: Renal epithelial and endothelial cells in the KOC model exhibited uptake of EVs from HF patients. HF-CRS EVs led to higher expression of renal injury markers (IL18, LCN2, HAVCR1) relative to non-CRS EVs. 15 EV-miRNAs were associated with creatinine, targeting 1143 gene targets specifying pathways relevant to renal injury, including TGF beta and AMPK signaling. We observed directionally consistent changes in the expression of TGF beta pathway members (BMP6, FST, TIMP3) in the KOC model exposed to CRS EVs, which were validated in epithelial cells treated with corresponding inhibitors and mimics of miRNAs. A similar trend was observed in renal tissue with kidney injury. Mendelian randomization suggested a role for FST in renal function. Conclusion: Plasma EVs in CRS patients elicit adverse transcriptional and phenotypic responses in a KOC model by regulating biologically relevant pathways, suggesting a role for EVs in CRS.
Authors
Emeli Chatterjee, Rodosthenis S. Rodosthenous, Ville J. Kujala, Priyanka Gokulnath, Michail Spanos, H. Immo Lehmann, Getulio P de Oliveira-Jr, Mingjian Shi, Tyne W. Miller-Fleming, Guoping Li, Ionita Ghiran, Katia Karalis, JoAnn Lindenfeld, Jonathan D. Mosley, Emily S. Lau, Jennifer E. Ho, Quanhu Sheng, Ravi Shah, Saumya Das
Abstract
BACKGROUND. Oxidized ApoB (oxLDL) and other oxidation-modified lipoproteins (OMLs), such as oxidized ApoA-I (oxHDL), are known pro-atherogenic factors. However, OMLs prognostic value for assessing high-risk coronary plaques by coronary computed tomography angiography (CCTA) has not been fully evaluated. METHODS. In a prospective, observational study, 306 participants with known cardiovascular disease (CVD) had extensive lipoprotein profiling, including plasma OMLs and HDL function measured. Proteomics analysis was performed on oxHDL isolated by anti-oxApoA-I antibody. Atherosclerotic plaque assessment was accomplished by quantitative CCTA (QAngio, Medis). RESULTS. Patients were predominantly white, overweight males (58.5%) on statin therapy (43.5%). Significant increases in LDL-C, ApoB, LDL-TG, sdLDL-C (P<0.001 for all), and TGs (P=0.03) were observed in high oxLDL group, accompanied by less efficient HDL function. High oxLDL was associated with necrotic (NB) (β=0.20; P<0.0001) and fibro-fatty (FFB) burdens (β=0.15; P=0.001) after multivariate adjustment. Low oxHDL had a significant reverse association with these plaque characteristics. Plasma oxHDL levels better predicted NB and FFB after adjustment (2.22, 1.27-3.88 and 2.80, 1.71-4.58) (ORs, 95% CIs) compared to oxLDL and HDL-C. Interestingly, oxHDL was associated with fibrous burden (FB) change over 3.3 years of follow-up (rho=0.535; P=0.033), when compared to oxLDL. Finally, combined Met(136) monooxidation and Trp(132) dioxidation of HDL showed the most evident association with CAC score (r=0.786; P<0.001) and FB (r=0.539; P=0.012) in high oxHDL, whereas Met(136) monooxidation significantly associated with high-risk plaque in low oxHDL. CONCLUSION. Our findings suggest that the investigated OMLs are associated with high-risk coronary plaque features and progression over time in CVD patients. TRIAL REGISTRATION. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01621594. FUNDING. This work was supported by the National Heart, Lung and Blood Institute (NHLBI) at the National Institutes of Health Intramural Research Program. The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Authors
Alexander V. Sorokin, Christin G. Hong, Angel M. Aponte, Elizabeth M. Florida, Jingrong Tang, Nidhi Patel, Irina N. Baranova, Haiou Li, Philip M. Parel, Vicky Chen, Sierra R. Wilson, Emily L. Ongstad, Anna Collén, Martin P. Playford, Thomas L. Eggerman, Marcus Y. Chen, Kazuhiko Kotani, Alexander V. Bocharov, Alan T. Remaley
Abstract
Diabetic cardiomyopathy, an increasingly global epidemic and a major cause of heart failure with preserved ejection fraction (HFpEF), is associated with hyperglycemia, insulin resistance, and intra-cardiomyocyte calcium mishandling. Here we identify that, in db/db mice with type 2 diabetes induced HFpEF, abnormal remodeling of cardiomyocyte transverse-tubule microdomains occurs with downregulation of the membrane scaffolding protein cardiac bridging integrator 1 (cBIN1). Transduction of cBIN1 by AAV9 gene therapy can restore transverse-tubule microdomains to normalize intracellular distribution of calcium handling proteins and, surprisingly, glucose transporter 4 (GLUT4). Cardiac proteomics revealed that AAV9-cBIN1 normalizes components of calcium handling and GLUT4 translocation machineries. Functional studies further identified that AAV9-cBIN1 normalizes insulin-dependent glucose uptake in diabetic cardiomyocytes. Phenotypically, AAV9-cBIN1 rescues cardiac lusitropy, improves exercise intolerance, and ameliorates hyperglycemia in diabetic mice. Restoration of transverse-tubule microdomains can improve cardiac function in the setting of diabetic cardiomyopathy, and also improve systemic glycemic control.
Authors
Jing Li, Bradley Richmond, Ahmad A. Cluntun, Ryan Bia, Maureen A. Walsh, Kikuyo Shaw, J. David Symons, Sarah Franklin, Jared Rutter, Katsuhiko Funai, Robin M. Shaw, TingTing Hong
Abstract
We investigated the extent, biologic characterization, phenotypic specificity, and possible regulation of a β1-adrenergic receptor–linked (β1-AR–linked) gene signaling network (β1-GSN) involved in left ventricular (LV) eccentric pathologic remodeling. A 430-member β1-GSN was identified by mRNA expression in transgenic mice overexpressing human β1-ARs or from literature curation, which exhibited opposite directional behavior in interventricular septum endomyocardial biopsies taken from patients with beta-blocker–treated, reverse remodeled dilated cardiomyopathies. With reverse remodeling, the major biologic categories and percentage of the dominant directional change were as follows: metabolic (19.3%, 81% upregulated); gene regulation (14.9%, 78% upregulated); extracellular matrix/fibrosis (9.1%, 92% downregulated); and cell homeostasis (13.3%, 60% upregulated). Regarding the comparison of β1-GSN categories with expression from 19,243 nonnetwork genes, phenotypic selection for major β1-GSN categories was exhibited for LV end systolic volume (contractility measure), ejection fraction (remodeling index), and pulmonary wedge pressure (wall tension surrogate), beginning at 3 months and persisting to study completion at 12 months. In addition, 121 lncRNAs were identified as possibly involved in cis-acting regulation of β1-GSN members. We conclude that an extensive 430-member gene network downstream from the β1-AR is involved in pathologic ventricular remodeling, with metabolic genes as the most prevalent category.
Authors
Philip D. Tatman, David P. Kao, Kathryn C. Chatfield, Ian A. Carroll, Jessica A. Wagner, Eric R. Jonas, Carmen C. Sucharov, J. David Port, Brian D. Lowes, Wayne A. Minobe, Sophia P. Huebler, Anis Karimpour-Fard, Erin M. Rodriguez, Stephen B. Liggett, Michael R. Bristow
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