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Nature Reviews. Cardiology Sep 2022Interest in epicardial adipose tissue (EAT) is growing rapidly, and research in this area appeals to a broad, multidisciplinary audience. EAT is unique in its anatomy... (Review)
Review
Interest in epicardial adipose tissue (EAT) is growing rapidly, and research in this area appeals to a broad, multidisciplinary audience. EAT is unique in its anatomy and unobstructed proximity to the heart and has a transcriptome and secretome very different from that of other fat depots. EAT has physiological and pathological properties that vary depending on its location. It can be highly protective for the adjacent myocardium through dynamic brown fat-like thermogenic function and harmful via paracrine or vasocrine secretion of pro-inflammatory and profibrotic cytokines. EAT is a modifiable risk factor that can be assessed with traditional and novel imaging techniques. Coronary and left atrial EAT are involved in the pathogenesis of coronary artery disease and atrial fibrillation, respectively, and it also contributes to the development and progression of heart failure. In addition, EAT might have a role in coronavirus disease 2019 (COVID-19)-related cardiac syndrome. EAT is a reliable potential therapeutic target for drugs with cardiovascular benefits such as glucagon-like peptide 1 receptor agonists and sodium-glucose co-transporter 2 inhibitors. This Review provides a comprehensive and up-to-date overview of the role of EAT in cardiovascular disease and highlights the translational nature of EAT research and its applications in contemporary cardiology.
Topics: Adipose Tissue; Atrial Fibrillation; COVID-19; Cardiology; Humans; Pericardium
PubMed: 35296869
DOI: 10.1038/s41569-022-00679-9 -
American Journal of Medical Genetics.... Mar 2020In 2014, an extensive review discussing the major steps of cardiac development focusing on growth, formation of primary and chamber myocardium and the development of the... (Review)
Review
In 2014, an extensive review discussing the major steps of cardiac development focusing on growth, formation of primary and chamber myocardium and the development of the cardiac electrical system, was published. Molecular genetic lineage analyses have since furthered our insight in the developmental origin of the various component parts of the heart, which currently can be unambiguously identified by their unique molecular phenotype. Moreover, genetic, molecular and cell biological analyses have driven insights into the mechanisms underlying the development of the different cardiac components. Here, we build on our previous review and provide an insight into the molecular mechanistic revelations that have forwarded the field of cardiac development. Despite the enormous advances in our knowledge over the last decade, the development of congenital cardiac malformations remains poorly understood. The challenge for the next decade will be to evaluate the different developmental processes using newly developed molecular genetic techniques to further unveil the gene regulatory networks operational during normal and abnormal cardiac development.
Topics: Gene Expression Regulation, Developmental; Gene Regulatory Networks; Heart; Heart Defects, Congenital; Heart Valves; Humans; Pericardium; Phenotype
PubMed: 32048790
DOI: 10.1002/ajmg.c.31778 -
Circulation Research Jul 2022Establishment of the myocardial wall requires proper growth cues from nonmyocardial tissues. During heart development, the epicardium and epicardium-derived cells...
BACKGROUND
Establishment of the myocardial wall requires proper growth cues from nonmyocardial tissues. During heart development, the epicardium and epicardium-derived cells instruct myocardial growth by secreting essential factors including FGF (fibroblast growth factor) 9 and IGF (insulin-like growth factor) 2. However, it is poorly understood how the epicardial secreted factors are regulated, in particular by chromatin modifications for myocardial formation. The current study is to investigate whether and how HDAC (histone deacetylase) 3 in the developing epicardium regulates myocardial growth.
METHODS
Various cellular and mouse models in conjunction with biochemical and molecular tools were employed to study the role of HDAC3 in the developing epicardium.
RESULTS
We deleted in the developing murine epicardium, and mutant hearts showed ventricular myocardial wall hypoplasia with reduction of epicardium-derived cells. The cultured embryonic cardiomyocytes with supernatants from knockout (KO) mouse epicardial cells also showed decreased proliferation. Genome-wide transcriptomic analysis revealed that and were significantly downregulated in KO mouse epicardial cells. We further found that and expression is dependent on HDAC3 deacetylase activity. The supplementation of FGF9 or IGF2 can rescue the myocardial proliferation defects treated by KO supernatant. Mechanistically, we identified that microRNA (miR)-322 and miR-503 were upregulated in KO mouse epicardial cells and epicardial KO hearts. Overexpression of miR-322 or miR-503 repressed FGF9 and IGF2 expression, while knockdown of miR-322 or miR-503 restored FGF9 and IGF2 expression in KO mouse epicardial cells.
CONCLUSIONS
Our findings reveal a critical signaling pathway in which epicardial HDAC3 promotes compact myocardial growth by stimulating FGF9 and IGF2 through repressing miR-322 or miR-503, providing novel insights in elucidating the etiology of congenital heart defects and conceptual strategies to promote myocardial regeneration.
Topics: Animals; Heart; Mice; MicroRNAs; Myocardium; Myocytes, Cardiac; Pericardium; Signal Transduction
PubMed: 35722872
DOI: 10.1161/CIRCRESAHA.122.320785 -
Nature Communications Mar 2021Cardiac patches are an effective way to deliver therapeutics to the heart. However, such procedures are normally invasive and difficult to perform. Here, we develop and...
Cardiac patches are an effective way to deliver therapeutics to the heart. However, such procedures are normally invasive and difficult to perform. Here, we develop and test a method to utilize the pericardial cavity as a natural "mold" for in situ cardiac patch formation after intrapericardial injection of therapeutics in biocompatible hydrogels. In rodent models of myocardial infarction, we demonstrate that intrapericardial injection is an effective and safe method to deliver hydrogels containing induced pluripotent stem cells-derived cardiac progenitor cells or mesenchymal stem cells-derived exosomes. After injection, the hydrogels form a cardiac patch-like structure in the pericardial cavity, mitigating immune response and increasing the cardiac retention of the therapeutics. With robust cardiovascular repair and stimulation of epicardium-derived cells, the delivered therapeutics mitigate cardiac remodeling and improve cardiac functions post myocardial infarction. Furthermore, we demonstrate the feasibility of minimally-invasive intrapericardial injection in a clinically-relevant porcine model. Collectively, our study establishes intrapericardial injection as a safe and effective method to deliver therapeutic-bearing hydrogels to the heart for cardiac repair.
Topics: Animals; Cardiac Surgical Procedures; Cardiovascular Agents; Cell Differentiation; Drug Delivery Systems; Exosomes; Extracellular Matrix; Hydrogels; Induced Pluripotent Stem Cells; Male; Materials Testing; Mesenchymal Stem Cells; Mice; Minimally Invasive Surgical Procedures; Myocardial Infarction; Myocytes, Cardiac; Pericardium; Rats; Swine
PubMed: 33658506
DOI: 10.1038/s41467-021-21682-7 -
Circulation Jun 2021Arrhythmogenic cardiomyopathy (ACM) manifests with sudden death, arrhythmias, heart failure, apoptosis, and myocardial fibro-adipogenesis. The phenotype typically starts...
BACKGROUND
Arrhythmogenic cardiomyopathy (ACM) manifests with sudden death, arrhythmias, heart failure, apoptosis, and myocardial fibro-adipogenesis. The phenotype typically starts at the epicardium and advances transmurally. Mutations in genes encoding desmosome proteins, including DSP (desmoplakin), are major causes of ACM.
METHODS
To delineate contributions of the epicardium to the pathogenesis of ACM, the allele was conditionally deleted in the epicardial cells in mice upon expression of tamoxifen-inducible Cre from the locus. Wild type (WT) and were crossed to Rosa26 (R26) dual reporter mice to tag the epicardial-derived cells with the EGFP (enhanced green fluorescent protein) reporter protein. Tagged epicardial-derived cells from adult :R26 and : R26 mouse hearts were isolated by fluorescence-activated cell staining and sequenced by single-cell RNA sequencing.
RESULTS
WT1 (Wilms tumor 1) expression was progressively restricted postnatally and was exclusive to the epicardium by postnatal day 21. Expression of was reduced in the epicardial cells but not in cardiac myocytes in the mice. The mice exhibited premature death, cardiac dysfunction, arrhythmias, myocardial fibro-adipogenesis, and apoptosis. Single-cell RNA sequencing of ≈18 000 EGFP-tagged epicardial-derived cells identified genotype-independent clusters of endothelial cells, fibroblasts, epithelial cells, and a very small cluster of cardiac myocytes, which were confirmed on coimmunofluorescence staining of the myocardial sections. Differentially expressed genes between the paired clusters in the 2 genotypes predicted activation of the inflammatory and mitotic pathways-including the TGFβ1 (transforming growth factor β1) and fibroblast growth factors-in the epicardial-derived fibroblast and epithelial clusters, but predicted their suppression in the endothelial cell cluster. The findings were corroborated by analysis of gene expression in the pooled RNA-sequencing data, which identified predominant dysregulation of genes involved in epithelial-mesenchymal transition, and dysregulation of 146 genes encoding the secreted proteins (secretome), including genes in the TGFβ1 pathway. Activation of the TGFβ1 and its colocalization with fibrosis in the :R26 mouse heart was validated by complementary methods.
CONCLUSIONS
Epicardial-derived cardiac fibroblasts and epithelial cells express paracrine factors, including TGFβ1 and fibroblast growth factors, which mediate epithelial-mesenchymal transition, and contribute to the pathogenesis of myocardial fibrosis, apoptosis, arrhythmias, and cardiac dysfunction in a mouse model of ACM. The findings uncover contributions of the epicardial-derived cells to the pathogenesis of ACM.
Topics: Animals; Cardiomyopathies; Disease Models, Animal; Humans; Mice; Paracrine Communication; Pericardium; Sequence Analysis, RNA; Single-Cell Analysis; Survival Analysis
PubMed: 33726497
DOI: 10.1161/CIRCULATIONAHA.120.052928 -
Cold Spring Harbor Perspectives in... Feb 2020The epicardium, the outermost tissue layer that envelops all vertebrate hearts, plays a crucial role in cardiac development and regeneration and has been implicated in... (Review)
Review
The epicardium, the outermost tissue layer that envelops all vertebrate hearts, plays a crucial role in cardiac development and regeneration and has been implicated in potential strategies for cardiac repair. The heterogenous cell population that composes the epicardium originates primarily from a transient embryonic cell cluster known as the proepicardial organ (PE). Characterized by its high cellular plasticity, the epicardium contributes to both heart development and regeneration in two critical ways: as a source of progenitor cells and as a critical signaling hub. Despite this knowledge, there are many unanswered questions in the field of epicardial biology, the resolution of which will advance the understanding of cardiac development and repair. We review current knowledge in cross-species epicardial involvement, specifically in relation to lineage specification and differentiation during cardiac development.
Topics: Animals; Cell Differentiation; Pericardium; Regeneration; Stem Cells
PubMed: 31451510
DOI: 10.1101/cshperspect.a037192 -
Clinical Medicine (London, England) Sep 2019
Topics: Atrial Fibrillation; Embolism, Air; Fistula; Humans; Pericardium
PubMed: 31530708
DOI: 10.7861/clinmedicine.19-5-431a -
Nature Biotechnology Dec 2023The epicardium, the mesothelial envelope of the vertebrate heart, is the source of multiple cardiac cell lineages during embryonic development and provides signals that...
The epicardium, the mesothelial envelope of the vertebrate heart, is the source of multiple cardiac cell lineages during embryonic development and provides signals that are essential to myocardial growth and repair. Here we generate self-organizing human pluripotent stem cell-derived epicardioids that display retinoic acid-dependent morphological, molecular and functional patterning of the epicardium and myocardium typical of the left ventricular wall. By combining lineage tracing, single-cell transcriptomics and chromatin accessibility profiling, we describe the specification and differentiation process of different cell lineages in epicardioids and draw comparisons to human fetal development at the transcriptional and morphological levels. We then use epicardioids to investigate the functional cross-talk between cardiac cell types, gaining new insights into the role of IGF2/IGF1R and NRP2 signaling in human cardiogenesis. Finally, we show that epicardioids mimic the multicellular pathogenesis of congenital or stress-induced hypertrophy and fibrotic remodeling. As such, epicardioids offer a unique testing ground of epicardial activity in heart development, disease and regeneration.
Topics: Humans; Pericardium; Heart; Myocardium; Cell Differentiation; Cell Lineage; Biology
PubMed: 37012447
DOI: 10.1038/s41587-023-01718-7 -
Journal of the American College of... Dec 2020
Topics: Hospitalization; Humans; Morbidity; Pericarditis; Pericardium; Risk Factors
PubMed: 33243383
DOI: 10.1016/j.jacc.2020.10.018 -
Journal of the American Heart... Sep 2020
Topics: Acute Coronary Syndrome; Adipose Tissue; Humans; Inflammation; Percutaneous Coronary Intervention; Pericardium
PubMed: 32856504
DOI: 10.1161/JAHA.120.018073