scholarly journals Increased Expression of the Innate Immune Receptor TLR10 in Obesity and Type-2 Diabetes: Association with ROS-Mediated Oxidative Stress

2018 ◽  
Vol 45 (2) ◽  
pp. 572-590 ◽  
Author(s):  
Sardar Sindhu ◽  
Nadeem Akhter ◽  
Shihab Kochumon ◽  
Reeby Thomas ◽  
Ajit Wilson ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Protein Expression ◽  
Mapk Signaling ◽  
Innate Immune ◽  
Low Grade ◽  
Sod Activity ◽  
Metabolic Inflammation

Background/Aims: Metabolic diseases such as obesity and type-2 diabetes (T2D) are known to be associated with chronic low-grade inflammation called metabolic inflammation together with an oxidative stress milieu found in the expanding adipose tissue. The innate immune Toll-like receptors (TLR) such as TLR2 and TLR4 have emerged as key players in metabolic inflammation; nonetheless, TLR10 expression in the adipose tissue and its significance in obesity/T2D remain unclear. Methods: TLR10 gene expression was determined in the adipose tissue samples from healthy non-diabetic and T2D individuals, 13 each, using real-time RT-PCR. TLR10 protein expression was determined by immunohistochemistry, confocal microscopy, and flow cytometry. Regarding in vitro studies, THP-1 cells, peripheral blood mononuclear cells (PBMC), or primary monocytes were treated with hydrogen peroxide (H2O2) for induction of reactive oxygen species (ROS)-mediated oxidative stress. Superoxide dismutase (SOD) activity was measured using a commercial kit. Data (mean±SEM) were compared using unpaired student’s t-test and P<0.05 was considered significant. Results: The adipose tissue TLR10 gene/protein expression was found to be significantly upregulated in obesity as well as T2D which correlated with body mass index (BMI). ROS-mediated oxidative stress induced high levels of TLR10 gene/protein expression in monocytic cells and PBMC. In these cells, oxidative stress induced a time-dependent increase in SOD activity. Pre-treatment of cells with anti-oxidants/ROS scavengers diminished the expression of TLR10. ROS-induced TLR10 expression involved the nuclear factor-kappaB (NF-κB)/mitogen activated protein kinase (MAPK) signaling as well as endoplasmic reticulum (ER) stress. H2O2-induced oxidative stress interacted synergistically with palmitate to trigger the expression of TLR10 which associated with enhanced expression of proinflammatory cytokines/chemokine. Conclusion: Oxidative stress induces the expression of TLR10 which may represent an immune marker for metabolic inflammation.

Lipopolysaccharide activates an innate immune system response in human adipose tissue in obesity and type 2 diabetes

2007 ◽  
Vol 292 (3) ◽  
pp. E740-E747 ◽  
Author(s):  
S. J. Creely ◽  
P. G. McTernan ◽  
C. M. Kusminski ◽  
ff. M. Fisher ◽  
N. F. Da Silva ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Protein Expression ◽  
Serum Insulin ◽  
Human Adipose Tissue ◽  
Innate Immune ◽  
System Response ◽  
Low Grade ◽  
Tnf Α

Type 2 diabetes (T2DM) is associated with chronic low-grade inflammation. Adipose tissue (AT) may represent an important site of inflammation. 3T3-L1 studies have demonstrated that lipopolysaccharide (LPS) activates toll-like receptors (TLRs) to cause inflammation. For this study, we 1) examined activation of TLRs and adipocytokines by LPS in human abdominal subcutaneous (AbdSc) adipocytes, 2) examined blockade of NF-κB in human AbdSc adipocytes, 3) examined the innate immune pathway in AbdSc AT from lean, obese, and T2DM subjects, and 4) examined the association of circulating LPS in T2DM subjects. The findings showed that LPS increased TLR-2 protein expression twofold ( P < 0.05). Treatment of AbdSc adipocytes with LPS caused a significant increase in TNF-α and IL-6 secretion (IL-6, Control: 2.7 ± 0.5 vs. LPS: 4.8 ± 0.3 ng/ml; P < 0.001; TNF-α, Control: 1.0 ± 0.83 vs. LPS: 32.8 ± 6.23 pg/ml; P < 0.001). NF-κB inhibitor reduced IL-6 in AbdSc adipocytes (Control: 2.7 ± 0.5 vs. NF-κB inhibitor: 2.1 ± 0.4 ng/ml; P < 0.001). AbdSc AT protein expression for TLR-2, MyD88, TRAF6, and NF-κB was increased in T2DM patients ( P < 0.05), and TLR-2, TRAF-6, and NF-κB were increased in LPS-treated adipocytes ( P < 0.05). Circulating LPS was 76% higher in T2DM subjects compared with matched controls. LPS correlated with insulin in controls ( r = 0.678, P < 0.0001). Rosiglitazone (RSG) significantly reduced both fasting serum insulin levels (reduced by 51%, P = 0.0395) and serum LPS (reduced by 35%, P = 0.0139) in a subgroup of previously untreated T2DM patients. In summary, our results suggest that T2DM is associated with increased endotoxemia, with AT able to initiate an innate immune response. Thus, increased adiposity may increase proinflammatory cytokines and therefore contribute to the pathogenic risk of T2DM.

scholarly journals Peroxisome Proliferator-Activated Receptor γ and Adipose Tissue—Understanding Obesity-Related Changes in Regulation of Lipid and Glucose Metabolism

2006 ◽  
Vol 92 (2) ◽  
pp. 386-395 ◽  
Author(s):  
Arya M. Sharma ◽  
Bart Staels
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Endocrine Function ◽  
Low Grade ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

Abstract Context: Adipose tissue is a metabolically dynamic organ, serving as a buffer to control fatty acid flux and a regulator of endocrine function. In obese subjects, and those with type 2 diabetes or the metabolic syndrome, adipose tissue function is altered (i.e. adipocytes display morphological differences alongside aberrant endocrine and metabolic function and low-grade inflammation). Evidence Acquisition: Articles on the role of peroxisome proliferator-activated receptor γ (PPARγ) in adipose tissue of healthy individuals and those with obesity, metabolic syndrome, or type 2 diabetes were sourced using MEDLINE (1990–2006). Evidence Synthesis: Articles were assessed to provide a comprehensive overview of how PPARγ-activating ligands improve adipose tissue function, and how this links to improvements in insulin resistance and the progression to type 2 diabetes and atherosclerosis. Conclusions: PPARγ is highly expressed in adipose tissue, where its activation with thiazolidinediones alters fat topography and adipocyte phenotype and up-regulates genes involved in fatty acid metabolism and triglyceride storage. Furthermore, PPARγ activation is associated with potentially beneficial effects on the expression and secretion of a range of factors, including adiponectin, resistin, IL-6, TNFα, plasminogen activator inhibitor-1, monocyte chemoattractant protein-1, and angiotensinogen, as well as a reduction in plasma nonesterified fatty acid supply. The effects of PPARγ also extend to macrophages, where they suppress production of inflammatory mediators. As such, PPARγ activation appears to have a beneficial effect on the relationship between the macrophage and adipocyte that is distorted in obesity. Thus, PPARγ-activating ligands improve adipose tissue function and may have a role in preventing progression of insulin resistance to diabetes and endothelial dysfunction to atherosclerosis.

scholarly journals Dendritic Cells in Subcutaneous and Epicardial Adipose Tissue of Subjects with Type 2 Diabetes, Obesity, and Coronary Artery Disease

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Miloš Mráz ◽  
Anna Cinkajzlová ◽  
Jana Kloučková ◽  
Zdeňka Lacinová ◽  
Helena Kratochvílová ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Coronary Artery Disease ◽  
Dendritic Cells ◽  
Adipose Tissue ◽  
Coronary Artery ◽  
Epicardial Adipose Tissue ◽  
Low Grade ◽  
Elective Cardiac Surgery ◽  
Artery Disease

Dendritic cells (DCs) are professional antigen-presenting cells contributing to regulation of lymphocyte immune response. DCs are divided into two subtypes: CD11c-positive conventional or myeloid (cDCs) and CD123-positive plasmacytoid (pDCs) DCs. The aim of the study was to assess DCs (HLA-DR+ lineage-) and their subtypes by flow cytometry in peripheral blood and subcutaneous (SAT) and epicardial (EAT) adipose tissue in subjects with (T2DM, n=12) and without (non-T2DM, n=17) type 2 diabetes mellitus undergoing elective cardiac surgery. Subjects with T2DM had higher fasting glycemia (8.6±0.7 vs. 5.8±0.2 mmol/l, p<0.001) and glycated hemoglobin (52.0±3.4 vs. 36.9±1.0 mmol/mol, p<0.001) and tended to have more pronounced inflammation (hsCRP: 9.8±3.1 vs. 5.1±1.9 mg/ml, p=0.177) compared with subjects without T2DM. T2DM was associated with reduced total DCs in SAT (1.57±0.65 vs. 4.45±1.56% for T2DM vs. non-T2DM, p=0.041) with a similar, albeit insignificant, trend in EAT (0.996±0.33 vs. 2.46±0.78% for T2DM vs. non-T2DM, p=0.171). When analyzing DC subsets, no difference in cDCs was seen between any of the studied groups or adipose tissue pools. In contrast, pDCs were increased in both SAT (13.5±2.0 vs. 4.6±1.9% of DC cells, p=0.005) and EAT (29.1±8.7 vs. 8.4±2.4% of DC, p=0.045) of T2DM relative to non-T2DM subjects as well as in EAT of the T2DM group compared with corresponding SAT (29.1±8.7 vs. 13.5±2.0% of DC, p=0.020). Neither obesity nor coronary artery disease (CAD) significantly influenced the number of total, cDC, or pDC in SAT or EAT according to multiple regression analysis. In summary, T2DM decreased the amount of total dendritic cells in subcutaneous adipose tissue and increased plasmacytoid dendritic cells in subcutaneous and even more in epicardial adipose tissue. These findings suggest a potential role of pDCs in the development of T2DM-associated adipose tissue low-grade inflammation.

scholarly journals Modulation of hyperglycemia and TNFα-mediated inflammation by helichrysum and grapefruit extracts in diabetic db/db mice

2014 ◽  
Vol 5 (9) ◽  
pp. 2120-2128 ◽  
Author(s):  
Ana Laura de la Garza ◽  
Usune Etxeberria ◽  
Sara Palacios-Ortega ◽  
Alexander G. Haslberger ◽  
Eva Aumueller ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Systemic Inflammation ◽  
Low Grade ◽  
P Type

Type-2 diabetes is associated with a chronic low-grade systemic inflammation accompanied by an increased production of adipokines/cytokines in the obese adipose tissue, which may be overcome by flavonoid-rich extracts.

scholarly journals Luteolin Improves Perivascular Adipose Tissue Profile and Vascular Dysfunction in Goto-Kakizaki Rats

2021 ◽  
Vol 22 (24) ◽  
pp. 13671
Author(s):  
Marcelo Queiroz ◽  
Adriana Leandro ◽  
Lara Azul ◽  
Artur Figueirinha ◽  
Raquel Seiça ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Endothelial Function ◽  
Metabolic Parameters ◽  
Perivascular Adipose Tissue ◽  
Gk Rats ◽  
Vascular Oxidative Stress ◽  
Luteolin Treatment

We investigated the effects of luteolin on metabolism, vascular reactivity, and perivascular adipose tissue (PVAT) in nonobese type 2 diabetes mellitus animal model, Goto-Kakizaki (GK) rats. Methods: Wistar and GK rats were divided in two groups: (1) control groups treated with vehicle; (2) groups treated with luteolin (10 mg/kg/day, for 2 months). Several metabolic parameters such as adiposity index, lipid profile, fasting glucose levels, glucose and insulin tolerance tests were determined. Endothelial function and contraction studies were performed in aortas with (PVAT+) or without (PVAT−) periaortic adipose tissue. We also studied vascular oxidative stress, glycation and assessed CRP, CCL2, and nitrotyrosine levels in PVAT. Results: Endothelial function was impaired in diabetic GK rats (47% (GK − PVAT) and 65% (GK + PVAT) inhibition of maximal endothelial dependent relaxation) and significantly improved by luteolin treatment (29% (GK − PVAT) and 22% (GK + PVAT) inhibition of maximal endothelial dependent relaxation, p < 0.01). Vascular oxidative stress and advanced glycation end-products’ levels were increased in aortic rings (~2-fold, p < 0.05) of diabetic rats and significantly improved by luteolin treatment (to levels not significantly different from controls). Periaortic adipose tissue anti-contractile action was significantly rescued with luteolin administration (p < 0.001). In addition, luteolin treatment significantly recovered proinflammatory and pro-oxidant PVAT phenotype, and improved systemic and metabolic parameters in GK rats. Conclusions: Luteolin ameliorates endothelial dysfunction in type 2 diabetes and exhibits therapeutic potential for the treatment of vascular complications associated with type 2 diabetes.

scholarly journals Vitamin D and inflammation in the prevention of type 2 diabetes: public health relevance

2012 ◽  
Vol 3 (4) ◽  
pp. 243
Author(s):  
Alaa Badawi ◽  
Eman Sadoun ◽  
Mohamed H. Al Thani
Keyword(s):  
Public Health ◽  
Type 2 Diabetes ◽  
Vitamin D ◽  
Immune System ◽  
Innate Immune System ◽  
Population Level ◽  
Innate Immune ◽  
Low Grade ◽  
Low Grade Inflammation

The incidence of type 2 diabetes mellitus (T2DM) is increasing worldwide. To reduce the disease risk and burden at the population level, preventative strategies should be developed with minimal cost and effort and with no side-effects. Low-grade inflammation resulting from imbalances in the innate immune system has been associated with an array of chronic disorders that predispose to the later development of T2DM (e.g., obesity, metabolic syndrome, and insulin resistance). As a result, inflammation may contribute to the pathogenesis of T2DM. Therefore, attenuation of this inflammatory response via modulating the innate immune system could lead to improved insulin sensitivity and delayed disease onset. Dietary supplementation with vitamin D may represent a novel strategy toward the prevention and control of T2DM at the population level due to its anti-inflammatory and antioxidant properties. This review examines current knowledge linking T2DM to chronic low-grade inflammation and the role of vitamin D in modulating this relationship. The concept that vitamin D, via attenuating inflammation, could be employed as a novel preventive measure for T2DM is evaluated in the context of its relevance to health care and public health practices.

Dysfunction of human subcutaneous fat arterioles in obesity alone or obesity associated with Type 2 diabetes

2011 ◽  
Vol 120 (10) ◽  
pp. 463-472 ◽  
Author(s):  
Adriana Georgescu ◽  
Doina Popov ◽  
Anamaria Constantin ◽  
Miruna Nemecz ◽  
Nicoleta Alexandru ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Protein Expression ◽  
Insulin Signalling ◽  
Subcutaneous Fat ◽  
Signalling Pathway ◽  
Internal Diameter ◽  
No Production ◽  
Insulin Signalling Pathway

The aim of the present study was to examine the effects of obesity alone and obesity associated with Type 2 diabetes on the structure, vascular reactivity and response to insulin of isolated human subcutaneous fat arterioles; these effects were correlated with the expression of insulin signalling proteins. Periumbilical subcutaneous adipose tissue was explanted during surgery, small arterioles (internal diameter 220±40 μm) were dissected out and investigated by electron microscopy, myography and immunoblotting. Compared with the subcutaneous arterioles of lean subjects, obesity activated the endothelium, enhanced the accumulation of collagen within vascular wall and increased the sensitivity of adrenergic response; obesity also diminished eNOS (endothelial NO synthase) protein expression, NO production, and endothelium-dependent and insulin-induced vasodilatation, as well as the protein expression of both IRS (insulin receptor substrates)-1 and IRS-2 and of the downstream molecules in the insulin signalling pathway, such as PI3K (phosphoinositide 3-kinase), phospho-Akt and Akt. When obesity was associated with Type 2 diabetes, these changes were significantly augmented. In conclusion, obesity alone or obesity associated with Type 2 diabetes alters human periumbilical adipose tissue arterioles in terms of structure, function and biochemsitry, including diminished eNOS expression and reduced levels of IRS-1, IRS-2, PI3K and Akt in the insulin signalling pathway.

scholarly journals Cardiac Autonomic Neuropathy: A Progressive Consequence of Chronic Low-Grade Inflammation in Type 2 Diabetes and Related Metabolic Disorders

2020 ◽  
Vol 21 (23) ◽  
pp. 9005
Author(s):  
Nour-Mounira Z. Bakkar ◽  
Haneen S. Dwaib ◽  
Souha Fares ◽  
Ali H. Eid ◽  
Yusra Al-Dhaheri ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Autonomic Neuropathy ◽  
Experimental Models ◽  
Cardiac Autonomic Neuropathy ◽  
Low Grade ◽  
Metabolic Inflammation ◽  
The Metabolic Syndrome ◽  
Cardiovascular Morbidity And Mortality

Cardiac autonomic neuropathy (CAN) is one of the earliest complications of type 2 diabetes (T2D), presenting a silent cause of cardiovascular morbidity and mortality. Recent research relates the pathogenesis of cardiovascular disease in T2D to an ensuing chronic, low-grade proinflammatory and pro-oxidative environment, being the hallmark of the metabolic syndrome. Metabolic inflammation emerges as adipose tissue inflammatory changes extending systemically, on the advent of hyperglycemia, to reach central regions of the brain. In light of changes in glucose and insulin homeostasis, dysbiosis or alteration of the gut microbiome (GM) emerges, further contributing to inflammatory processes through increased gut and blood–brain barrier permeability. Interestingly, studies reveal that the determinants of oxidative stress and inflammation progression exist at the crossroad of CAN manifestations, dictating their evolution along the natural course of T2D development. Indeed, sympathetic and parasympathetic deterioration was shown to correlate with markers of adipose, vascular, and systemic inflammation. Additionally, evidence points out that dysbiosis could promote a sympatho-excitatory state through differentially affecting the secretion of hormones and neuromodulators, such as norepinephrine, serotonin, and γ-aminobutyric acid, and acting along the renin–angiotensin–aldosterone axis. Emerging neuronal inflammation and concomitant autophagic defects in brainstem nuclei were described as possible underlying mechanisms of CAN in experimental models of metabolic syndrome and T2D. Drugs with anti-inflammatory characteristics provide potential avenues for targeting pathways involved in CAN initiation and progression. The aim of this review is to delineate the etiology of CAN in the context of a metabolic disorder characterized by elevated oxidative and inflammatory load.

scholarly journals Systemic Oxidative Stress and Visceral Adipose Tissue Mediators of NLRP3 Inflammasome and Autophagy Are Reduced in Obese Type 2 Diabetic Patients Treated with Metformin

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 892
Author(s):  
Zaida Abad-Jiménez ◽  
Sandra López-Domènech ◽  
Rubén Díaz-Rúa ◽  
Francesca Iannantuoni ◽  
Segundo Ángel Gómez-Abril ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Adipose Tissue ◽  
Visceral Adipose Tissue ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Diabetic Patients ◽  
Low Grade ◽  
Obese Patients ◽  
Visceral Adipose

Obesity is a low-grade inflammatory condition affecting a range of individuals, from metabolically healthy obese (MHO) subjects to type 2 diabetes (T2D) patients. Metformin has been shown to display anti-inflammatory properties, though the underlying molecular mechanisms are unclear. To study whether the effects of metformin are mediated by changes in the inflammasome complex and autophagy in visceral adipose tissue (VAT) of obese patients, a biopsy of VAT was obtained from a total of 68 obese patients undergoing gastric bypass surgery. The patients were clustered into two groups: MHO patients and T2D patients treated with metformin. Patients treated with metformin showed decreased levels of all analyzed serum pro-inflammatory markers (TNFα, IL6, IL1β and MCP1) and a downwards trend in IL18 levels associated with a lower production of oxidative stress markers in leukocytes (mitochondrial ROS and myeloperoxidase (MPO)). A reduction in protein levels of MCP1, NFκB, NLRP3, ASC, ATG5, Beclin1 and CHOP and an increase in p62 were also observed in the VAT of the diabetic group. This downregulation of both the NLRP3 inflammasome and autophagy in VAT may be associated with the improved inflammatory profile and leukocyte homeostasis seen in obese T2D patients treated with metformin with respect to MHO subjects and endorses the cardiometabolic protective effect of this drug.

Gut microbiota in health and disease: an overview focused on metabolic inflammation

2016 ◽  
Vol 7 (2) ◽  
pp. 181-194 ◽  
Author(s):  
R. Nagpal ◽  
M. Kumar ◽  
A.K. Yadav ◽  
R. Hemalatha ◽  
H. Yadav ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Gut Microbiota ◽  
Intestinal Barrier ◽  
Adverse Outcomes ◽  
Special Focus ◽  
Low Grade ◽  
Immune Functions ◽  
Metabolic Inflammation

In concern to the continuously rising global prevalence of obesity, diabetes and associated diseases, novel preventive and therapeutic approaches are urgently required. However, to explore and develop such innovative strategies, a meticulous comprehension of the biological basis of these diseases is extremely important. Past decade has witnessed an enormous amount of research investigation and advancement in the field of obesity, diabetes and metabolic syndrome, with the gut microbiota receiving a special focus in the triangle of nutrition, health and diseases. In particular, the role of gut microbiota in health and diseases has been one of the most vigorous and intriguing field of recent research; however, much still remains to be elucidated about its precise role in host metabolism and immune functions and its implication in the onset, progression as well as in the amelioration of metabolic ailments. Recent investigations have suggested a significant contribution of the gut microbiota in the regulation and impairment of energy homeostasis, thereby causing metabolic disorders, such as metabolic endotoxemia, insulin resistance and type 2 diabetes. Numerous inflammatory biomarkers have been found to be associated with obesity, diabetes and risk of other associated adverse outcomes, thereby suggesting that a persistent low-grade inflammatory response is a potential risk factor. In this milieu, this review intends to discuss potential evidences supporting the disturbance of the gut microbiota balance and the intestinal barrier permeability as a potential triggering factor for systemic inflammation in the onset and progression of obesity, type 2 diabetes and metabolic syndrome.

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