scholarly journals Inflammatory Microenvironment and Adipogenic Differentiation in Obesity: The Inhibitory Effect of Theobromine in a Model of Human Obesity In Vitro

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Maria Pia Fuggetta ◽  
Manuela Zonfrillo ◽  
Cristina Villivà ◽  
Enzo Bonmassar ◽  
Giampiero Ravagnan
Keyword(s):  
Adipose Tissue ◽  
Proinflammatory Cytokines ◽  
Adipogenic Differentiation ◽  
Inhibitory Effect ◽  
Low Grade ◽  
Tissue Inflammation ◽  
Inflammatory Microenvironment ◽  
Adipocyte Cell ◽  
Inflammatory State

Objective. Obesity is considered a clinic condition characterized by a state of chronic low-grade inflammation. The role of macrophages and adipocytokines in adipose tissue inflammation is in growing investigation. The physiopathological mechanisms involved in inflammatory state in obesity are not fully understood though the adipocytokines seem to characterize the biochemical link between obesity and inflammation. The aim of this work is to analyze the effect of theobromine, a methylxanthine present in the cocoa, on adipogenesis and on proinflammatory cytokines evaluated in a model of fat tissue inflammation in vitro. Methods. In order to mimic in vitro this inflammatory condition, we investigated the interactions between human-like macrophages U937 and human adipocyte cell lines SGBS. The effect of theobromine on in vitro cell growth, cell cycle, adipogenesis, and cytokines release in the supernatants has been evaluated. Results. Theobromine significantly inhibits the differentiation of preadipocytes in mature adipocytes and reduces the levels of proinflammatory cytokines as MCP-1 and IL-1β in the supernatants obtained by the mature adipocytes and macrophages interaction. Conclusion. Theobromine reduces adipogenesis and proinflammatory cytokines; these data suggest its potential therapeutic effect for treating obesity by control of macrophages infiltration in adipose tissue and inflammation.

scholarly journals Resolution of Adipose Tissue Inflammation

2010 ◽  
Vol 10 ◽  
pp. 832-856 ◽  
Author(s):  
Ana González-Périz ◽  
Joan Clària
Keyword(s):  
Adipose Tissue ◽  
Lipid Mediators ◽  
Current Status ◽  
Critical Event ◽  
Low Grade ◽  
Adipose Tissue Inflammation ◽  
Nonalcoholic Fatty Liver ◽  
Tissue Inflammation ◽  
Inflammatory State ◽  
Anti Inflammatory

The presence of the so-called “low-grade” inflammatory state is recognized as a critical event in adipose tissue dysfunction in obesity. This chronic “low-grade” inflammation in white adipose tissue is powerfully augmented through the infiltration of macrophages, which, together with adipocytes, perpetuate a vicious cycle of macrophage recruitment and secretion of free fatty acids and deleterious adipokines that predispose the development of obesity-related comorbidities, such as insulin resistance and nonalcoholic fatty liver disease. In the last decade, many factors have been identified that contribute to mounting uncontrolled inflammation in obese adipose tissue. Among them, bioactive lipid mediators derived from the cyclooxygenase and 5-lipoxygenase pathways, which convert the ω-6-polyunsaturated fatty acid (PUFA) arachidonic acid into potent proinflammatory eicosanoids (i.e., prostaglandins [PGs] and leukotrienes), have emerged. Interestingly, the same lipid mediators that initially trigger the inflammatory response also signal the termination of inflammation by stimulating the biosynthesis of anti-inflammatory and proresolving lipid autacoids. This review discusses the current status, characteristics, and progress in this class of “stop signals”, including the lipoxins, which were the first identified ω-6 PUFA–derived lipid mediators with potent anti-inflammatory properties; the recently described ω-3 PUFA–derived lipid mediators resolvins and protectins; and the cyclopentenone PGs of the D series. Special emphasis is given to the participation of these bioactive lipid autacoids in the resolution of adipose tissue inflammation and in preventing the development of obesity-related complications.

scholarly journals Effects of des-acyl ghrelin on insulin sensitivity and macrophage polarization in adipose tissue

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fang Yuan ◽  
Qianqian Zhang ◽  
Haiyan Dong ◽  
Xinxin Xiang ◽  
Weizhen Zhang ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
The Body ◽  
Control Group ◽  
Low Grade ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Arginase 1 ◽  
Acyl Ghrelin

Abstract Background and Objectives Obesity is the accumulation of adipose tissue caused by excess energy in the body, accompanied by long-term chronic low-grade inflammation of adipose tissue. More than 50% of interstitial cells in adipose tissue are macrophages, which produce cytokines closely related to insulin resistance. Macrophage biology is driven by two polarization phenotypes, M1 (proinflammatory) and M2 (anti-inflammatory). This study aimed to investigate the effect of gastric hormone des-acyl ghrelin (DAG) on the polarization phenotype of macrophages and elucidate the role of macrophages in adipose tissue inflammation and insulin sensitivity and its molecular mechanism. Methods Mice were subcutaneously administrated with DAG in osmotic minipumps. The mice were fed a normal diet or a high-fat diet (HFD). Different macrophage markers were detected by real-time revere transcription polymerase chain reaction. Results Exogenous administration of DAG significantly inhibited the increase of adipocyte volume caused by HFD and reduced the number of rosette-like structures in adipose tissue. HFD in the control group significantly increased M1 macrophage markers, tumor necrosis factor α (TNFα), and inducible NO synthase (iNOS). However, these increases were reduced or even reversed after DAG administration in vitro. The M2 markers, macrophage galactose type C-type Lectin-1 (MGL1), arginase 1 (Arg1), and macrophage mannose receptor 1 (MRC1) were decreased by HFD, and the downward trend was inhibited or reversed after DAG administration. Although Arg1 was elevated after HFD, the fold increase after DAG administration in vitro was much greater than that in the control group. Conclusion DAG inhibits adipose tissue inflammation caused by HFD, reduces infiltration of macrophages in adipose tissue, and promotes polarization of macrophages to M2, thus alleviating obesity and improving insulin sensitivity.

scholarly journals Anti-inflammatory role of Gpnmb in adipose tissue of mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bernadette Nickl ◽  
Fatimunnisa Qadri ◽  
Michael Bader
Keyword(s):  
Adipose Tissue ◽  
Body Weight Gain ◽  
Blood Lipid ◽  
Low Grade ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Inflammatory Stimuli ◽  
Knockout Animals

AbstractObesity can cause a chronic, low-grade inflammation, which is a critical step in the development of type II diabetes and cardiovascular diseases. Inflammation is associated with the expression of glycoprotein nonmetastatic melanoma protein b (Gpnmb), which is mainly expressed by macrophages and dendritic cells. We generated a Gpnmb-knockout mouse line using Crispr-Cas9 to assess the role of Gpnmb in a diet-induced obesity. The absence of Gpnmb did not affect body weight gain and blood lipid parameters. While wildtype animals became obese but remained otherwise metabolically healthy, Gpnmb-knockout animals developed, in addition to obesity, symptoms of metabolic syndrome such as adipose tissue inflammation, insulin resistance and liver fibrosis. We observed a strong Gpnmb expression in adipose tissue macrophages in wildtype animals and a decreased expression of most macrophage-related genes independent of their inflammatory function. This was corroborated by in vitro data showing that Gpnmb was mostly expressed by reparative macrophages while only pro-inflammatory stimuli induced shedding of Gpnmb. The data suggest that Gpnmb is ameliorating adipose tissue inflammation independent of the polarization of macrophages. Taken together, the data suggest an immune-balancing function of Gpnmb that could delay the metabolic damage caused by the induction of obesity.

scholarly journals Chemotactic cytokines, obesity and type 2 diabetes:in vivoandin vitroevidence for a possible causal correlation?

2009 ◽  
Vol 68 (4) ◽  
pp. 378-384 ◽  
Author(s):  
Henrike Sell ◽  
Jürgen Eckel
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Low Grade ◽  
Obese Patients ◽  
Tissue Mass ◽  
Tissue Biology ◽  
Wide Range ◽  
Adipose Tissue Mass

A strong causal link between increased adipose tissue mass and insulin resistance in tissues such as liver and skeletal muscle exists in obesity-related disorders such as type 2 diabetes. Increased adipose tissue mass in obese patients and patients with diabetes is associated with altered secretion of adipokines, which also includes chemotactic proteins. Adipose tissue releases a wide range of chemotactic proteins including many chemokines and chemerin, which are interesting targets for adipose tissue biology and for biomedical research in obesity and obesity-related diseases. This class of adipokines may be directly linked to a chronic state of low-grade inflammation and macrophage infiltration in adipose tissue, a concept intensively studied in adipose tissue biology in recent years. The inflammatory state of adipose tissue in obese patients may be the most important factor linking increased adipose tissue mass to insulin resistance. Furthermore, chemoattractant adipokines may play an important role in this situation, as many of these proteins possess biological activity beyond the recruitment of immune cells including effects on adipogenesis and glucose homeostasis in insulin-sensitive tissues. The present review provides a summary of experimental evidence of the role of adipose tissue-derived chemotactic cytokines and their function in insulin resistancein vivoandin vitro.

scholarly journals Adipose tissue inflammation and metabolic dysfunction: a clinical perspective

2013 ◽  
Vol 15 (1) ◽  
Author(s):  
Charmaine S. Tam ◽  
Leanne M. Redman
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Low Grade ◽  
Metabolic Dysfunction ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Proinflammatory Mediators ◽  
Low Grade Inflammation

AbstractObesity is characterized by a state of chronic low-grade inflammation due to increased immune cells, specifically infiltrated macrophages into adipose tissue, which in turn secrete a range of proinflammatory mediators. This nonselective low-grade inflammation of adipose tissue is systemic in nature and can impair insulin signaling pathways, thus, increasing the risk of developing insulin resistance and type 2 diabetes. The aim of this review is to provide an update on clinical studies examining the role of adipose tissue in the development of obesity-associated complications in humans. We will discuss adipose tissue inflammation during different scenarios of energy imbalance and metabolic dysfunction including obesity and overfeeding, weight loss by calorie restriction or bariatric surgery, and conditions of insulin resistance (diabetes, polycystic ovarian syndrome).

Abstract 3672: Loss of Perivascular Adipocyte Paracrine Function Leads to Increased Vascular Tone and Glucose Intolerance in Hypertension

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kaivan Khavandi ◽  
Adam Greenstein ◽  
Sarah Withers ◽  
Kazuhiko Sonoyama ◽  
Sarah Lewis ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Vascular Tone ◽  
Tnf Alpha ◽  
Perivascular Adipose Tissue ◽  
The Metabolic Syndrome ◽  
Adipocyte Cell ◽  
Therapeutic Opportunity

In order to investigate the contribution of perivascular adipose tissue (PVAT) to arterial function, a total of 55 small arteries harvested from 35 skin biopsies of patients with Metabolic Syndrome and matched controls were mounted as ring preparations in a wire myograph. Contractility to cumulative doses of Norepinephrine in the presence or absence of PVAT showed an anticontractile effect in arteries from healthy volunteers (p=0.009), which was lost in patients with Metabolic Syndrome. Bioassay studies confirmed that PVAT releases a hydrophilic anticontractile factor in health, which is absent in obesity. Using a soluble fragment of the human Type 1 receptor, we identified that the anticontractile factor was adiponectin, which is the sole mediator of vasodilation, acting by increasing endothelial bioavailability of nitric oxide. Significant endothelial dysfunction was observed in patients with Metabolic Syndrome (p<0.001). Quantitative image analysis of adipose tissue revealed significantly increased adipocyte cell size in patients with Metabolic Syndrome, compared with healthy controls (p<0.006). There was immunohistochemical evidence of inflammation with upregulation of TNF-alpha receptor 1 in these patients (p<0.001). Application of exogenous TNF-alpha abolished the anticontractile effect of PVAT by reducing adiponectin bioavailability. Oxidative stress also induced by cytokines TNF-alpha and IL-6 but not IL-1, reduced adiponectin production from PVAT and increased basal tone. When the obese microenvironment was replicated in vitro by inflicting hypoxia on PVAT, adiponectin activity was lost but then rescued by incubation with cytokine antagonists. Further application of the adiponectin receptor fragment abolished PVAT relaxation. We conclude that in healthy arteries, PVAT releases adiponectin which reduces vascular tone. In obesity, this is lost by a cascade of adipocyte hypertrophy, hypoxia, inflammation and oxidative stress. The resulting vasoconstriction contributes to hypertension, hypertriglyceridaemia and insulin resistance. Direct targeting of adiponectin release from PVAT therefore provides a novel therapeutic opportunity in the Metabolic Syndrome.

Neonatal IL-4 exposure decreases adipogenesis of male rats into adulthood

2021 ◽  
Author(s):  
Tammy Ying ◽  
Thea N. Golden ◽  
Lan Cheng ◽  
Jeff Ishibashi ◽  
Patrick Seale ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Neonatal Period ◽  
Uncoupling Protein ◽  
Adipogenic Differentiation ◽  
Male Rats ◽  
Interleukin 4 ◽  
Sprague Dawley ◽  
Fat Cell ◽  
Subcutaneous White Adipose Tissue

The cytokine interleukin 4 (IL-4) can increase beige adipogenesis in adult rodents. However, neonatal animals use a distinct adipocyte precursor compartment for adipogenesis compared to adults. In this study, we address whether IL-4 can induce persistent effects on adipose tissue when administered subcutaneously in the interscapular region during the neonatal period in Sprague Dawley rats. We injected IL-4 into neonatal male rats during postnatal days 1-6, followed by analysis of adipose tissue and adipocyte precursors at 2 weeks and 10 weeks of age. Adipocyte precursors were cultured and subjected to differentiation in vitro. We found that a short and transient IL-4 exposure in neonates upregulated uncoupling protein 1 (Ucp1) mRNA expression and decreased fat cell size in subcutaneous white adipose tissue (WAT). Adipocyte precursors from mature rats that had been treated with IL-4 as neonates displayed a decrease in adiponectin (Adipoq) but no change in Ucp1 expression, as compared to controls. Thus, neonatal IL-4 induces acute beige adipogenesis and decreases adipogenic differentiation capacity long term. Overall, these findings indicate that the neonatal period is critical for adipocyte development and may influence the later onset of obesity.

scholarly journals Decreased TLR3 in Hyperplastic Adipose Tissue, Blood and Inflamed Adipocytes is Related to Metabolic Inflammation

2018 ◽  
Vol 51 (3) ◽  
pp. 1051-1068 ◽  
Author(s):  
Jèssica Latorre ◽  
José M. Moreno-Navarrete ◽  
Mónica Sabater ◽  
Maria Buxo ◽  
José I. Rodriguez-Hermosa ◽  
...  
Keyword(s):  
Weight Loss ◽  
Adipose Tissue ◽  
Low Grade ◽  
Metabolic Inflammation ◽  
Fat Depots ◽  
Acute Surgery ◽  
Obese Subjects ◽  
Anti Inflammatory ◽  
The Impact

Background/Aims: Obesity is characterized by the immune activation that eventually dampens insulin sensitivity and changes metabolism. This study explores the impact of different inflammatory/ anti-inflammatory paradigms on the expression of toll-like receptors (TLR) found in adipocyte cultures, adipose tissue, and blood. Methods: We evaluated by real time PCR the impact of acute surgery stress in vivo (adipose tissue) and macrophages (MCM) in vitro (adipocytes). Weight loss was chosen as an anti-inflammatory model, so TLR were analyzed in fat samples collected before and after bariatric surgery-induced weight loss. Associations with inflammatory and metabolic parameters were analyzed in non-obese and obese subjects, in parallel with gene expression measures taken in blood and isolated adipocytes/ stromal-vascular cells (SVC). Treatments with an agonist of TLR3 were conducted in human adipocyte cultures under normal conditions and upon conditions that simulated the chronic low-grade inflammatory state of obesity. Results: Surgery stress raised TLR1 and TLR8 in subcutaneous (SAT), and TLR2 in SAT and visceral (VAT) adipose tissue, while decreasing VAT TLR3 and TLR4. MCM led to increased TLR2 and diminished TLR3, TLR4, and TLR5 expressions in human adipocytes. The anti-inflammatory impact of weight loss was concomitant with decreased TLR1, TLR3, and TLR8 in SAT. Cross-sectional associations confirmed increased V/ SAT TLR1 and TLR8, and decreased TLR3 in obese patients, as compared with non-obese subjects. As expected, TLR were predominant in SVC and adipocyte precursor cells, even though expression of all of them but TLR8 (very low levels) was also found in ex vivo isolated and in vitro differentiated adipocytes. Among SVC, CD14+ macrophages showed increased TLR1, TLR2, and TLR7, but decreased TLR3 mRNA. The opposite patterns shown for TLR2 and TLR3 in V/ SAT, SVC, and inflamed adipocytes were observed in blood as well, being TLR3 more likely linked to lymphocyte instead of neutrophil counts. On the other hand, decreased TLR3 in adipocytes challenged with MCM dampened lipogenesis and the inflammatory response to Poly(I:C). Conclusion: Functional variations in the expression of TLR found in blood and hypertrophied fat depots, namely decreased TLR3 in lymphocytes and inflamed adipocytes, are linked to metabolic inflammation.

scholarly journals Amidation-Modified Apelin-13 Regulates PPARγ and Perilipin to Inhibit Adipogenic Differentiation and Promote Lipolysis

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Sha Wang ◽  
Guoying Gao ◽  
Yiwei He ◽  
Qiong Li ◽  
Zhan Li ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Adipogenic Differentiation ◽  
Animal Experiments ◽  
Endocrine System ◽  
Average Diameter ◽  
Lifestyle Changes ◽  
Biologically Active ◽  
Regulation Mechanism ◽  
Prevalence Of Obesity

With the adjustment of human diet and lifestyle changes, the prevalence of obesity is increasing year by year. Obesity is closely related to the excessive accumulation of white adipose tissue (WAT), which can synthesize and secrete a variety of adipokines. Apelin is a biologically active peptide in the adipokines family. Past studies have shown that apelin plays an important regulatory role in the pathogenesis and pathophysiology of diseases such as the cardiovascular system, respiratory system, digestive system, nervous system, and endocrine system. Apelin is also closely related to diabetes and obesity. Therefore, we anticipate that apelin-13 has an effect on lipometabolism and intend to explore the effect of apelin-13 on lipometabolism at the cellular and animal levels. In in vitro experiments, amidation-modified apelin-13 can significantly reduce the lipid content; TG content; and the expression of PPARγ, perilipin mRNA, and protein in adipocytes. Animal experiments also show that amidation modification apelin-13 can improve the abnormal biochemical indicators of diet-induced obesity (DOI) rats and can reduce the average diameter of adipocytes in adipose tissue, the concentration of glycerol, and the expression of PPARγ and perilipin mRNA and protein. Our results show that apelin-13 can affect the metabolism of adipose tissue, inhibit adipogenic differentiation of adipocytes, promote lipolysis, and thereby improve obesity. The mechanism may be regulating the expression of PPARγ to inhibit adipogenic differentiation and regulating the expression of perilipin to promote lipolysis. This study helps us understand the role of apelin-13 in adipose tissue and provide a basis for the elucidation of the regulation mechanism of lipometabolism and the development of antiobesity drugs.

scholarly journals Loss of Oncostatin M Signaling in Adipocytes Induces Insulin Resistance and Adipose Tissue Inflammation in Vivo

2016 ◽  
Vol 291 (33) ◽  
pp. 17066-17076 ◽  
Author(s):  
Carrie M. Elks ◽  
Peng Zhao ◽  
Ryan W. Grant ◽  
Hardy Hang ◽  
Jennifer L. Bailey ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Cell Types ◽  
Oncostatin M ◽  
Adipose Tissue Inflammation ◽  
High Fat ◽  
Tissue Inflammation ◽  
Fat Feeding

Oncostatin M (OSM) is a multifunctional gp130 cytokine. Although OSM is produced in adipose tissue, it is not produced by adipocytes. OSM expression is significantly induced in adipose tissue from obese mice and humans. The OSM-specific receptor, OSM receptor β (OSMR), is expressed in adipocytes, but its function remains largely unknown. To better understand the effects of OSM in adipose tissue, we knocked down Osmr expression in adipocytes in vitro using siRNA. In vivo, we generated a mouse line lacking Osmr in adiponectin-expressing cells (OSMRFKO mice). The effects of OSM on gene expression were also assessed in vitro and in vivo. OSM exerts proinflammatory effects on cultured adipocytes that are partially rescued by Osmr knockdown. Osm expression is significantly increased in adipose tissue T cells of high fat-fed mice. In addition, adipocyte Osmr expression is increased following high fat feeding. OSMRFKO mice exhibit increased insulin resistance and adipose tissue inflammation and have increased lean mass, femoral length, and bone volume. Also, OSMRFKO mice exhibit increased expression of Osm, the T cell markers Cd4 and Cd8, and the macrophage markers F4/80 and Cd11c. Interestingly, the same proinflammatory genes induced by OSM in adipocytes are induced in the adipose tissue of the OSMRFKO mouse, suggesting that increased expression of proinflammatory genes in adipose tissue arises both from adipocytes and other cell types. These findings suggest that adipocyte OSMR signaling is involved in the regulation of adipose tissue homeostasis and that, in obesity, OSMR ablation may exacerbate insulin resistance by promoting adipose tissue inflammation.

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