Epigenetic Mechanisms in Monocytes/Macrophages Regulate Inflammation in Cardiometabolic and Vascular Disease

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Cardiometabolic and vascular disease, with their associated secondary complications, are the leading cause of morbidity and mortality in Western society. Chronic inflammation is a common theme that underlies initiation and progression of cardiovascular disease. In this regard, monocyte-macrophages are key players in the development of a chronic inflammatory state. Over the past decade, epigenetic modifications, such as DNA methylation and post-translational histone processing, have emerged as important regulators of immune cell phenotypes. Accumulating studies reveal the importance of epigenetic enzymes in the dynamic regulation of key signaling pathways that alter monocyte-macrophage phenotypes in response to environmental stimuli. In this review, we highlight the current paradigms of monocyte-macrophage polarization and the emerging role of epigenetic modification in the regulation of monocyte-macrophage phenotype in obesity, diabetes, atherosclerosis and abdominal aortic aneurysms.

Related collections

Most cited references 73

Record: found
Abstract: found
Article: not found

The DNA methyltransferases of mammals.

T Bestor (2000)

The biological significance of 5-methylcytosine was in doubt for many years, but is no longer. Through targeted mutagenesis in mice it has been learnt that every protein shown by biochemical tests to be involved in the establishment, maintenance or interpretation of genomic methylation patterns is encoded by an essential gene. A human genetic disorder (ICF syndrome) has recently been shown to be caused by mutations in the DNA methyltransferase 3B (DNMT3B) gene. A second human disorder (Rett syndrome) has been found to result from mutations in the MECP2 gene, which encodes a protein that binds to methylated DNA. Global genome demethylation caused by targeted mutations in the DNA methyltransferase-1 (Dnmt1) gene has shown that cytosine methylation plays essential roles in X-inactivation, genomic imprinting and genome stabilization. The majority of genomic 5-methylcytosine is now known to enforce the transcriptional silence of the enormous burden of transposons and retroviruses that have accumulated in the mammalian genome. It has also become clear that programmed changes in methylation patterns are less important in the regulation of mammalian development than was previously believed. Although a number of outstanding questions have yet to be answered (one of these questions involves the nature of the cues that designate sites for methylation at particular stages of gametogenesis and early development), studies of DNA methyltransferases are likely to provide further insights into the biological functions of genomic methylation patterns.

0 comments Cited 435 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Comprehensive analysis of CpG islands in human chromosomes 21 and 22.

Daiya Takai, Peter A. Jones (2002)

CpG islands are useful markers for genes in organisms containing 5-methylcytosine in their genomes. In addition, CpG islands located in the promoter regions of genes can play important roles in gene silencing during processes such as X-chromosome inactivation, imprinting, and silencing of intragenomic parasites. The generally accepted definition of what constitutes a CpG island was proposed in 1987 by Gardiner-Garden and Frommer [Gardiner-Garden, M. & Frommer, M. (1987) J. Mol. Biol. 196, 261-282] as being a 200-bp stretch of DNA with a C+G content of 50% and an observed CpG/expected CpG in excess of 0.6. Any definition of a CpG island is somewhat arbitrary, and this one, which was derived before the sequencing of mammalian genomes, will include many sequences that are not necessarily associated with controlling regions of genes but rather are associated with intragenomic parasites. We have therefore used the complete genomic sequences of human chromosomes 21 and 22 to examine the properties of CpG islands in different sequence classes by using a search algorithm that we have developed. Regions of DNA of greater than 500 bp with a G+C equal to or greater than 55% and observed CpG/expected CpG of 0.65 were more likely to be associated with the 5' regions of genes and this definition excluded most Alu-repetitive elements. We also used genome sequences to show strong CpG suppression in the human genome and slight suppression in Drosophila melanogaster and Saccharomyces cerevisiae. This finding is compatible with the recent detection of 5-methylcytosine in Drosophila, and might suggest that S. cerevisiae has, or once had, CpG methylation.

0 comments Cited 349 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Self-renewing resident cardiac macrophages limit adverse remodeling following myocardial infarction

Sarah Dick, Jill Macklin, Sara Nejat … (2018)

Macrophages promote both injury and repair following myocardial infarction, but discriminating functions within mixed populations remains challenging. Here we used fate mapping and single-cell transcriptomics to demonstrate that at steady state, TIMD4+LYVE1+MHC-IIloCCR2− resident cardiac macrophages self-renew with negligible blood monocyte input. Monocytes partially replaced resident TIMD4−LYVE1−MHC-IIhiCCR2− macrophages and fully replaced TIMD4−LYVE1−MHC-IIhiCCR2+ macrophages, revealing a hierarchy of monocyte contribution to functionally distinct macrophage subsets. Ischemic injury reduced TIMD4+ and TIMD4− resident macrophage abundance within infarcted tissue while recruited, CCR2+ monocyte-derived macrophages adopted multiple cell fates, including those nearly indistinguishable from resident macrophages. Despite this similarity, inducible depletion of resident macrophages using a Cx3cr1-based system led to impaired cardiac function and promoted adverse remodeling primarily within the peri-infarct zone, highlighting a non-redundant, cardioprotective role of resident cardiac macrophages. Lastly, we demonstrate the ability of TIMD4 to be used as a durable lineage marker of a subset of resident cardiac macrophages.