scholarly journals Leukocyte Heterogeneity in Adipose Tissue, Including in Obesity

2020 ◽  
Vol 126 (11) ◽  
pp. 1590-1612 ◽  
Author(s):  
Ada Weinstock ◽  
Hernandez Moura Silva ◽  
Kathryn J. Moore ◽  
Ann Marie Schmidt ◽  
Edward A. Fisher
Keyword(s):  
Adipose Tissue ◽  
Immune Cells ◽  
Immune Cell ◽  
Γδ T Cells ◽  
The United States ◽  
Low Grade ◽  
Obesity Prevalence ◽  
Cell Level ◽  
Mortality And Morbidity ◽  
Molecular Investigation

Adipose tissue (AT) plays a central role in both metabolic health and pathophysiology. Its expansion in obesity results in increased mortality and morbidity, with contributions to cardiovascular disease, diabetes mellitus, fatty liver disease, and cancer. Obesity prevalence is at an all-time high and is projected to be 50% in the United States by 2030. AT is home to a large variety of immune cells, which are critical to maintain normal tissue functions. For example, γδ T cells are fundamental for AT innervation and thermogenesis, and macrophages are required for recycling of lipids released by adipocytes. The expansion of visceral white AT promotes dysregulation of its immune cell composition and likely promotes low-grade chronic inflammation, which has been proposed to be the underlying cause for the complications of obesity. Interestingly, weight loss after obesity alters the AT immune compartment, which may account for the decreased risk of developing these complications. Recent technological advancements that allow molecular investigation on a single-cell level have led to the discovery of previously unappreciated heterogeneity in many organs and tissues. In this review, we will explore the heterogeneity of immune cells within the visceral white AT and their contributions to homeostasis and pathology.

scholarly journals Aerobic training reduces immune cell recruitment and cytokine levels in adipose tissue in obese mice

2019 ◽  
Vol 44 (5) ◽  
pp. 512-520 ◽  
Author(s):  
Débora Romualdo Lacerda ◽  
Michele Macedo Moraes ◽  
Albená Nunes-Silva ◽  
Kátia Anunciação Costa ◽  
Débora Fernandes Rodrigues ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Immune Cells ◽  
Aerobic Training ◽  
Immune Cell ◽  
Control Diet ◽  
Moderate Intensity ◽  
Low Grade ◽  
Carbohydrate Diet ◽  
Cytokine Levels ◽  
Low Grade Inflammation

Obesity is associated with an energy imbalance that results from excessive energy intake, low diet quality, and a sedentary lifestyle. The increased consumption of a high-refined carbohydrate (HC) diet is strongly related to higher adiposity and low-grade inflammation. Aerobic training is a well-known nonpharmacological intervention to treat obesity and metabolic disturbances. However, the mechanisms through which aerobic training ameliorates the low-grade inflammation induced by an HC diet should be further investigated. Our hypothesis herein was that aerobic training would decrease the recruitment of leukocytes in adipose tissue, thereby reducing the levels of cytokines and improving metabolism in mice fed an HC diet. Male Balb/c mice were assigned to the following groups: control diet/nontrained (C-NT), control diet/trained (C-T), high-refined carbohydrate diet/nontrained (HC-NT), and high-refined carbohydrate diet/trained (HC-T). Mice were submitted to moderate-intensity training sessions that consisted of running 60 min per day for 8 weeks. An intravital microscopy technique was performed in vivo in anesthetized mice to visualize the microvasculature of the adipose tissue. The HC diet induced obesity and increased the influx of immune cells into the adipose tissue. In contrast, HC-T mice presented a lower adiposity and adipocyte area. Furthermore, relative to HC-NT mice, HC-T mice showed increased resting energy expenditure, decreased recruitment of immune cells in the adipose tissue, reduced cytokine levels, and ameliorated hyperglycemia and fatty liver deposition. Collectively, our data enhance understanding about the anti-inflammatory effect of aerobic training and shed light on the adipose tissue-mediated mechanisms by which training promotes a healthier metabolic profile.

scholarly journals Identification of Three Significant Genes Associated with Immune Cells Infiltration in Dysfunctional Adipose Tissue-Induced Insulin-Resistance of Obese Patients via Comprehensive Bioinformatics Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ming Zhai ◽  
Peipei Luan ◽  
Yefei Shi ◽  
Bo Li ◽  
Jianhua Kang ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Correlation Analysis ◽  
Immune Cells ◽  
Plasma Cells ◽  
Immune Cell ◽  
Low Grade ◽  
Hub Genes ◽  
Bioinformatics Analyses ◽  
Adipose Tissue Macrophages

Background. Low-grade chronic inflammation in dysfunctional adipose tissue links obesity with insulin resistance through the activation of tissue-infiltrating immune cells. Numerous studies have reported on the pathogenesis of insulin-resistance. However, few studies focused on genes from genomic database. In this study, we would like to explore the correlation of genes and immune cells infiltration in adipose tissue via comprehensive bioinformatics analyses and experimental validation in mice and human adipose tissue. Methods. Gene Expression Omnibus (GEO) datasets (GSE27951, GSE55200, and GSE26637) of insulin-resistant individuals or type 2 diabetes patients and normal controls were downloaded to get differently expressed genes (DEGs), and GO and KEGG pathway analyses were performed. Subsequently, we integrated DEGs from three datasets and constructed commonly expressed DEGs’ PPI net-works across datasets. Center regulating module of DEGs and hub genes were screened through MCODE and cytoHubba in Cytoscape. Three most significant hub genes were further analyzed by GSEA analysis. Moreover, we verified the predicted hub genes by performing RT qPCR analysis in animals and human samples. Besides, the relative fraction of 22 immune cell types in adipose tissue was detected by using the deconvolution algorithm of CIBERSORT (Cell Type Identification by Estimating Relative Subsets of RNA Transcripts). Furthermore, based on the significantly changed types of immune cells, we performed correlation analysis between hub genes and immune cells. And, we performed immunohistochemistry and immunofluorescence analysis to verify that the hub genes were associated with adipose tissue macrophages (ATM). Results. Thirty DEGs were commonly expressed across three datasets, most of which were upregulated. DEGs mainly participated in the process of multiple immune cells’ infiltration. In protein-protein interaction network, we identified CSF1R, C1QC, and TYROBP as hub genes. GSEA analysis suggested high expression of the three hub genes was correlated with immune cells functional pathway’s activation. Immune cell infiltration and correlation analysis revealed that there were significant positive correlations between TYROBP and M0 macrophages, CSF1R and M0 macrophages, Plasma cells, and CD8 T cells. Finally, hub genes were associated with ATMs infiltration by experimental verification. Conclusions. This article revealed that CSF1R, C1QC, and TYROBP were potential hub genes associated with immune cells’ infiltration and the function of proinflammation, especially adipose tissue macrophages, in the progression of obesity-induced diabetes or insulin-resistance.

scholarly journals Dietary Fatty Acids at the Crossroad between Obesity and Colorectal Cancer: Fine Regulators of Adipose Tissue Homeostasis and Immune Response

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1738
Author(s):  
Manuela Del Cornò ◽  
Rosaria Varì ◽  
Beatrice Scazzocchio ◽  
Barbara Varano ◽  
Roberta Masella ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Transcription Factors ◽  
Immune Cells ◽  
Immune Cell ◽  
Response To Therapy ◽  
Dietary Fatty Acids ◽  
Low Grade ◽  
Cell Functions

Colorectal cancer (CRC) is among the major threatening diseases worldwide, being the third most common cancer, and a leading cause of death, with a global incidence expected to increase in the coming years. Enhanced adiposity, particularly visceral fat, is a major risk factor for the development of several tumours, including CRC, and represents an important indicator of incidence, survival, prognosis, recurrence rates, and response to therapy. The obesity-associated low-grade chronic inflammation is thought to be a key determinant in CRC development, with the adipocytes and the adipose tissue (AT) playing a significant role in the integration of diet-related endocrine, metabolic, and inflammatory signals. Furthermore, AT infiltrating immune cells contribute to local and systemic inflammation by affecting immune and cancer cell functions through the release of soluble mediators. Among the factors introduced with diet and enriched in AT, fatty acids (FA) represent major players in inflammation and are able to deeply regulate AT homeostasis and immune cell function through gene expression regulation and by modulating the activity of several transcription factors (TF). This review summarizes human studies on the effects of dietary FA on AT homeostasis and immune cell functions, highlighting the molecular pathways and TF involved. The relevance of FA balance in linking diet, AT inflammation, and CRC is also discussed. Original and review articles were searched in PubMed without temporal limitation up to March 2021, by using fatty acid as a keyword in combination with diet, obesity, colorectal cancer, inflammation, adipose tissue, immune cells, and transcription factors.

scholarly journals Involvement of Microglia in the Pathophysiology of Intracranial Aneurysms and Vascular Malformations—A Short Overview

2021 ◽  
Vol 22 (11) ◽  
pp. 6141
Author(s):  
Teodora Larisa Timis ◽  
Ioan Alexandru Florian ◽  
Sergiu Susman ◽  
Ioan Stefan Florian
Keyword(s):  
Immune Cells ◽  
Arteriovenous Malformations ◽  
Intracranial Aneurysms ◽  
Immune Cell ◽  
Vascular Malformations ◽  
Cerebral Injury ◽  
Future Research ◽  
Mortality And Morbidity ◽  
The Central Nervous System ◽  
The Brain

Aneurysms and vascular malformations of the brain represent an important source of intracranial hemorrhage and subsequent mortality and morbidity. We are only beginning to discern the involvement of microglia, the resident immune cell of the central nervous system, in these pathologies and their outcomes. Recent evidence suggests that activated proinflammatory microglia are implicated in the expansion of brain injury following subarachnoid hemorrhage (SAH) in both the acute and chronic phases, being also a main actor in vasospasm, considerably the most severe complication of SAH. On the other hand, anti-inflammatory microglia may be involved in the resolution of cerebral injury and hemorrhage. These immune cells have also been observed in high numbers in brain arteriovenous malformations (bAVM) and cerebral cavernomas (CCM), although their roles in these lesions are currently incompletely ascertained. The following review aims to shed a light on the most significant findings related to microglia and their roles in intracranial aneurysms and vascular malformations, as well as possibly establish the course for future research.

scholarly journals HIF1α activation in dendritic cells under sterile conditions promotes an anti-inflammatory phenotype through accumulation of intracellular lipids

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Elizabeth G. Wood ◽  
Claire E. Macdougall ◽  
Hazel Blythe ◽  
Marc Clément ◽  
Romain A. Colas ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Cell Function ◽  
Immune Cell ◽  
Lipid Synthesis ◽  
Mortality And Morbidity ◽  
Intracellular Lipids ◽  
Adipose Tissue Dysfunction ◽  
Disease Mortality ◽  
Key Factor ◽  
Inflammatory Phenotype

AbstractObesity is among the leading causes of elevated cardiovascular disease mortality and morbidity. Adipose tissue dysfunction, insulin resistance and inflammation are recognized as important risk factors for the development of cardiovascular disorders in obesity. Hypoxia appears to be a key factor in adipose tissue dysfunction affecting not only adipocytes but also immune cell function. Here we examined the effect of hypoxia-induced transcription factor HIF1α activation on classical dendritic cell (cDCs) function during obesity. We found that deletion of Hif1α on cDCs results in enhanced adipose-tissue inflammation and atherosclerotic plaque formation in a mouse model of obesity. This effect is mediated by HIF1α-mediated increased lipid synthesis, accumulation of lipid droplets and alter synthesis of lipid mediators. Our findings demonstrate that HIF1α activation in cDCs is necessary to control vessel wall inflammation.

scholarly journals B Lymphocytes and Adipose Tissue Inflammation

2020 ◽  
Vol 40 (5) ◽  
pp. 1110-1122 ◽  
Author(s):  
Prasad Srikakulapu ◽  
Coleen A. McNamara
Keyword(s):  
Adipose Tissue ◽  
B Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
Metabolic Dysfunction ◽  
Adipose Tissue Inflammation ◽  
Cell Type ◽  
Tissue Inflammation ◽  
B Cell Subsets

The immune system plays an important role in obesity-induced adipose tissue inflammation and the resultant metabolic dysfunction, which can lead to hypertension, dyslipidemia, and insulin resistance and their downstream sequelae of type 2 diabetes mellitus and cardiovascular disease. While macrophages are the most abundant immune cell type in adipose tissue, other immune cells are also present, such as B cells, which play important roles in regulating adipose tissue inflammation. This brief review will overview B-cell subsets, describe their localization in various adipose depots and summarize our knowledge about the function of these B-cell subsets in regulating adipose tissue inflammation, obesity-induced metabolic dysfunction and atherosclerosis.

scholarly journals Adiponectin as Link Factor between Adipose Tissue and Cancer

2019 ◽  
Vol 20 (4) ◽  
pp. 839 ◽  
Author(s):  
Erika Di Zazzo ◽  
Rita Polito ◽  
Silvia Bartollino ◽  
Ersilia Nigro ◽  
Carola Porcile ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Immune Cells ◽  
Active Role ◽  
Low Grade ◽  
Poor Clinical Outcome ◽  
Different Types ◽  
Obesity And Cancer ◽  
Low Grade Inflammation ◽  
Circulating Levels ◽  
Proliferation And Invasion

Adipose tissue is a key regulator of energy balance playing an active role in lipid storage as well as in synthesizing several hormones directly involved in the pathogenesis of obesity. Obesity represents a peculiar risk factor for a growing list of cancers and is frequently associated to poor clinical outcome. The mechanism linking obesity and cancer is not completely understood, but, amongst the major players, there are both chronic low-grade inflammation and deregulation of adipokines secretion. In obesity, the adipose tissue is pervaded by an abnormal number of immune cells that create an inflammatory environment supporting tumor cell proliferation and invasion. Adiponectin (APN), the most abundant adipokine, shows anti-inflammatory, anti-proliferative and pro-apoptotic properties. Circulating levels of APN are drastically decreased in obesity, suggesting that APN may represent the link factor between obesity and cancer risk. The present review describes the recent advances on the involvement of APN and its receptors in the etiology of different types of cancer.

scholarly journals NLRP3 Inflammasome Activation in Adipose Tissues and Its Implications on Metabolic Diseases

2020 ◽  
Vol 21 (11) ◽  
pp. 4184 ◽  
Author(s):  
Kelvin Ka-Lok Wu ◽  
Samson Wing-Ming Cheung ◽  
Kenneth King-Yip Cheng
Keyword(s):  
Adipose Tissue ◽  
Nlrp3 Inflammasome ◽  
Metabolic Disorders ◽  
Immune Cell ◽  
Diabetic Patients ◽  
Inflammasome Activation ◽  
Low Grade ◽  
Adipose Tissues ◽  
Adipose Tissue Dysfunction ◽  
Nlrp3 Inflammasome Activation

Adipose tissue is an active endocrine and immune organ that controls systemic immunometabolism via multiple pathways. Diverse immune cell populations reside in adipose tissue, and their composition and immune responses vary with nutritional and environmental conditions. Adipose tissue dysfunction, characterized by sterile low-grade chronic inflammation and excessive immune cell infiltration, is a hallmark of obesity, as well as an important link to cardiometabolic diseases. Amongst the pro-inflammatory factors secreted by the dysfunctional adipose tissue, interleukin (IL)-1β, induced by the NLR family pyrin domain-containing 3 (NLRP3) inflammasome, not only impairs peripheral insulin sensitivity, but it also interferes with the endocrine and immune functions of adipose tissue in a paracrine manner. Human studies indicated that NLRP3 activity in adipose tissues positively correlates with obesity and its metabolic complications, and treatment with the IL-1β antibody improves glycaemia control in type 2 diabetic patients. In mouse models, genetic or pharmacological inhibition of NLRP3 activation pathways or IL-1β prevents adipose tissue dysfunction, including inflammation, fibrosis, defective lipid handling and adipogenesis, which in turn alleviates obesity and its related metabolic disorders. In this review, we summarize both the negative and positive regulators of NLRP3 inflammasome activation, and its pathophysiological consequences on immunometabolism. We also discuss the potential therapeutic approaches to targeting adipose tissue inflammasome for the treatment of obesity and its related metabolic disorders.

The role of innate immune cells in obese adipose tissue inflammation and development of insulin resistance

2013 ◽  
Vol 109 (03) ◽  
pp. 399-406 ◽  
Author(s):  
Triantafyllos Chavakis ◽  
Jindrich Chmelar ◽  
Kyoung-Jin Chung
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Immune Cells ◽  
Cytotoxic T Cells ◽  
Innate Immune ◽  
Low Grade ◽  
Innate Immune Cells ◽  
Metabolic Complications ◽  
Adaptive Immune Cells

SummaryObesity is characterised by a chronic state of low-grade inflammation in different tissues including the vasculature. There is a causal link between adipose tissue (AT) inflammation and obesity-related metabolic complications, such as the development of insulin resistance and subsequently of type 2 diabetes. Intense efforts in the recent years have aimed at dissecting the pathophysiology of AT inflammation. The role of both innate and adaptive immune cells, such as macrophages or cytotoxic T cells in AT inflammation has been demonstrated. Besides these cells, more leukocyte subpopulations have been recently implicated in obesity, including neutrophils and eosinophils, mast cells, natural killer cells or dendritic cells. The involvement of multiple leukocyte subpopulations underlines the complexity of obesity-associated AT inflammation. In this review, we discuss the role of innate immune cells in AT inflammation, obesity and related metabolic disorders.

scholarly journals Adipose Tissue in Obesity-Related Inflammation and Insulin Resistance: Cells, Cytokines, and Chemokines

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Kassem Makki ◽  
Philippe Froguel ◽  
Isabelle Wolowczuk
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Immune Cells ◽  
Metabolic Regulation ◽  
Immune Cell ◽  
Suppressor Cells ◽  
Cell Types ◽  
Immune Functions ◽  
Cytokines And Chemokines ◽  
Wide Range

Adipose tissue is a complex organ that comprises a wide range of cell types with diverse energy storage, metabolic regulation, and neuroendocrine and immune functions. Because it contains various immune cells, either adaptive (B and T lymphocytes; such as regulatory T cells) or innate (mostly macrophages and, more recently identified, myeloid-derived suppressor cells), the adipose tissue is now considered as a bona fide immune organ, at the cross-road between metabolism and immunity. Adipose tissue disorders, such as those encountered in obesity and lipodystrophy, cause alterations to adipose tissue distribution and function with broad effects on cytokine, chemokine, and hormone expression, on lipid storage, and on the composition of adipose-resident immune cell populations. The resulting changes appear to induce profound consequences for basal systemic inflammation and insulin sensitivity. The purpose of this review is to synthesize the current literature on adipose cell composition remodeling in obesity, which shows how adipose-resident immune cells regulate inflammation and insulin resistance—notably through cytokine and chemokine secretion—and highlights major research questions in the field.

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