scholarly journals Adipokine inflammation and insulin resistance: the role of glucose, lipids and endotoxin

2012 ◽  
Vol 216 (1) ◽  
pp. T1-T15 ◽  
Author(s):  
M K Piya ◽  
P G McTernan ◽  
S Kumar
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Human Adipose Tissue ◽  
Dietary Factors ◽  
Positive Energy ◽  
Low Grade ◽  
Positive Energy Balance ◽  
Secretory Tissue ◽  
The Impact ◽  
Low Grade Inflammation

Adipose tissue is an active endocrine organ, and our knowledge of this secretory tissue, in recent years, has led us to completely rethink how our body functions and becomes dysregulated with weight gain. Human adipose tissue appears to act as a multifunctional secretory organ with the capacity to control energy homoeostasis through peripheral and central regulation of energy homoeostasis. It also plays an important role in innate immunity. However, the capability to more than double its original mass to cope with positive energy balance in obesity leads to many pathogenic changes. These changes arise within the adipose tissue as well as inducing secondary detrimental effects on other organs like muscle and liver, including chronic low-grade inflammation mediated by adipocytokines (adipokine inflammation). This inflammation is modulated by dietary factors and nutrients including glucose and lipids, as well as gut bacteria in the form of endotoxin or LPS. The aim of this current review is to consider the impact of nutrients such as glucose and lipids on inflammatory pathways, specifically within adipose tissue. Furthermore, how nutrients such as these can influence adipokine inflammation and consequently insulin resistance directly through their effects on secretion of adipocytokines (TNFα, IL6 and resistin) as well as indirectly through increases in endotoxin is discussed.

scholarly journals Meta-fibrosis links positive energy balance and mitochondrial metabolism to insulin resistance

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1758 ◽  
Author(s):  
Daniel S. Lark ◽  
David H. Wasserman
Keyword(s):  
Insulin Resistance ◽  
Extracellular Matrix ◽  
Energy Balance ◽  
Positive Energy ◽  
Extracellular Matrix Remodeling ◽  
Low Grade ◽  
Matrix Remodeling ◽  
Matrix Expansion ◽  
Positive Energy Balance ◽  
Low Grade Inflammation

Obesity and insulin resistance often emerge from positive energy balance and generally are linked to low-grade inflammation. This low-grade inflammation has been called “meta-inflammation” because it is a consequence of the metabolic dysregulation that can accompany overnutrition. One means by which meta-inflammation is linked to insulin resistance is extracellular matrix expansion secondary to meta-inflammation, which we define here as “meta-fibrosis”. The significance of meta-fibrosis is that it reflects a situation in which the extracellular matrix functions as a multi-level integrator of local (for example, mitochondrial reactive oxygen species production) and systemic (for example, inflammation) inputs that couple to cellular processes creating insulin resistance. While adipose tissue extracellular matrix remodeling has received considerable attention, it is becoming increasingly apparent that liver and skeletal muscle extracellular matrix remodeling also contributes to insulin resistance. In this review, we address recent advances in our understanding of energy balance, mitochondrial energetics, meta-inflammation, and meta-fibrosis in the development of insulin resistance.

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).

scholarly journals Osteopontin Expression in Human and Murine Obesity: Extensive Local Up-Regulation in Adipose Tissue but Minimal Systemic Alterations

Endocrinology ◽  
2007 ◽  
Vol 149 (3) ◽  
pp. 1350-1357 ◽  
Author(s):  
Florian W. Kiefer ◽  
Maximilian Zeyda ◽  
Jelena Todoric ◽  
Joakim Huber ◽  
René Geyeregger ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Plasma Concentrations ◽  
Morbidly Obese ◽  
Low Grade ◽  
Obese Patients ◽  
Multifunctional Protein ◽  
Inflammatory Processes ◽  
Low Grade Inflammation

Obesity is associated with a chronic low-grade inflammation characterized by macrophage infiltration of adipose tissue (AT) that may underlie the development of insulin resistance and type 2 diabetes. Osteopontin (OPN) is a multifunctional protein involved in various inflammatory processes, cell migration, and tissue remodeling. Because these processes occur in the AT of obese patients, we studied in detail the regulation of OPN expression in human and murine obesity. The study included 20 morbidly obese patients and 20 age- and sex-matched control subjects, as well as two models (diet-induced and genetic) of murine obesity. In high-fat diet-induced and genetically obese mice, OPN expression was drastically up-regulated in AT (40 and 80-fold, respectively) but remained largely unaltered in liver (<2-fold). Moreover, OPN plasma concentrations remained unchanged in both murine models of obesity, suggesting a particular local but not systemic importance for OPN. OPN expression was strongly elevated also in the AT of obese patients compared with lean subjects in both omental and sc AT. In addition, we detected three OPN isoforms to be expressed in human AT and, strikingly, an obesity induced alteration of the OPN isoform expression pattern. Analysis of AT cellular fractions revealed that OPN is exceptionally highly expressed in AT macrophages in humans and mice. Moreover, OPN expression in AT macrophages was strongly up-regulated by obesity. In conclusion, our data point toward a specific local role of OPN in obese AT. Therefore, OPN could be a critical regulator in obesity induced AT inflammation and insulin resistance.

scholarly journals Adipose tissue macrophages in aging-associated adipose tissue function

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Bangchao Lu ◽  
Liang Huang ◽  
Juan Cao ◽  
Lingling Li ◽  
Wenhui Wu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Therapeutic Targets ◽  
Visceral Adiposity ◽  
Low Grade ◽  
Recent Advances ◽  
Adipose Tissue Macrophages ◽  
Low Grade Inflammation

Abstract“Inflammaging” refers to the chronic, low-grade inflammation that characterizes aging. Aging, like obesity, is associated with visceral adiposity and insulin resistance. Adipose tissue macrophages (ATMs) have played a major role in obesity-associated inflammation and insulin resistance. Macrophages are elevated in adipose tissue in aging. However, the changes and also possibly functions of ATMs in aging and aging-related diseases are unclear. In this review, we will summarize recent advances in research on the role of adipose tissue macrophages with aging-associated insulin resistance and discuss their potential therapeutic targets for preventing and treating aging and aging-related diseases.

Low-grade inflammation in insulin resistance associates with bacterial load in adipose tissue

2019 ◽  
Author(s):  
S Tabei ◽  
L Scheffler ◽  
R Chakaroun ◽  
S Ziesche ◽  
A Crane ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Bacterial Load ◽  
Low Grade ◽  
Low Grade Inflammation

scholarly journals TIR-Domain-Containing Adaptor-Inducing Interferon-β (TRIF) Is Involved in Glucose Metabolism in Adipose Tissue through the Insulin/AKT Signaling Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Junling Yang ◽  
Ken-Ichiro Fukuchi
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Epididymal Adipose Tissue ◽  
Chow Diet ◽  
Low Grade ◽  
Interferon Β ◽  
Tlr Signaling ◽  
Normal Chow ◽  
Low Grade Inflammation

Obesity significantly increases the risk of developing type 2 diabetes mellitus and other metabolic diseases. Obesity is associated with chronic low-grade inflammation in white adipose tissues, which is thought to play an essential role in developing insulin resistance. Many lines of evidence indicate that toll-like receptors (TLRs) and their downstream signaling pathways are involved in development of chronic low-grade inflammation and insulin resistance, which are associated with obesity. Mice lacking molecules positively involved in the TLR signaling pathways are generally protected from high-fat diet-induced inflammation and insulin resistance. In this study, we have determined the effects of genetic deficiency of toll/interleukin-1 receptor-domain-containing adaptor-inducing interferon-β (TRIF) on food intake, bodyweight, glucose metabolism, adipose tissue macrophage polarization, and insulin signaling in normal chow diet-fed mice to investigate the role of the TRIF-dependent TLR signaling in adipose tissue metabolism and inflammation. TRIF deficiency (TRIF−/−) increased food intake and bodyweight. The significant increase in bodyweight in TRIF−/− mice was discernible as early as 24 weeks of age and sustained thereafter. TRIF−/− mice showed impaired glucose tolerance in glucose tolerance tests, but their insulin tolerance tests were similar to those in TRIF+/+ mice. Although no difference was found in the epididymal adipose mass between the two groups, the percentage of CD206+ M2 macrophages in epididymal adipose tissue decreased in TRIF−/− mice compared with those in TRIF+/+ mice. Furthermore, activation of epididymal adipose AKT in response to insulin stimulation was remarkably diminished in TRIF−/− mice compared with TRIF+/+ mice. Our results indicate that the TRIF-dependent TLR signaling contributes to maintaining insulin/AKT signaling and M2 macrophages in epididymal adipose tissue under a normal chow diet and provide new evidence that TLR4-targeted therapies for type 2 diabetes require caution.

scholarly journals Effect of Social Factors and the Natural Environment on the Etiology and Pathogenesis of Diabetes Mellitus

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Guangtong Dong ◽  
Lianlian Qu ◽  
Xuefeng Gong ◽  
Bing Pang ◽  
Weitian Yan ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Natural Environment ◽  
Social Factors ◽  
Blood Glucose Control ◽  
Public Health Problem ◽  
Special Focus ◽  
Low Grade ◽  
The Impact ◽  
Low Grade Inflammation

Type 2 diabetes mellitus (T2DM) is currently a public health problem worldwide and a threat to human health and social development. The incidence rate of the disease is steadily increasing. Various genetic and environmental factors have been established as influencing the pathogenesis of this disease. However, the influence of social factors and the natural environment on DM incidence should also be considered. Low-grade inflammation could represent a central point of connection integrating all these potential triggers, being partly responsible for the development of insulin resistance. This paper aims to elaborate on the impact of the natural environment and social factors on DM development, with a special focus on six aspects of the pathogenesis of DM: pollution, radiation, psychology, drink, sleep, and exercise. We identified a two-way relationship between T2DM and social and natural environments. Changes in these environments may lead to low-grade inflammation, which in turn induces or aggravates T2DM and vice versa. Poor lifestyle may lead to increased insulin resistance and promote DM development. Improvements in blood glucose control can be achieved through nonenvironmental and behavioral interventions.

scholarly journals Subcutaneous Adipose Stem Cells in Obesity: The Impact of Bariatric Surgery

2021 ◽  
Author(s):  
Veronica Mocanu ◽  
Daniel V. Timofte ◽  
Ioana Hristov
Keyword(s):  
Insulin Resistance ◽  
Bariatric Surgery ◽  
Stem Cells ◽  
Weight Loss ◽  
Adipose Tissue ◽  
Adipogenic Differentiation ◽  
Low Grade ◽  
Potential Weight ◽  
Subcutaneous Adipose ◽  
The Impact

Adipocyte expansion, which involves adipose tissue-derived mesenchymal stem cells (ASCs), is a critical process with implications in the pathogenesis of metabolic syndrome and insulin resistance associated with obesity. Impaired subcutaneous adipogenesis leads to dysfunctional, hypertrophic adipocytes, chronic low-grade inflammation, and peripheric insulin resistance. Alternatively, it has also been proposed that the preservation of the functionality of subcutaneous adipocyte precursors could contribute to some obese individuals remaining metabolically healthy. Very few studies evaluated the changes in the adipogenic differentiation for human subcutaneous ASCs following bariatric surgery. Weight loss after bariatric surgery involves extensive remodeling of adipose tissue, comprising the hyperplasia-hypertrophy balance. Subcutaneous ASCs may be implicated in the variations of bariatric outcomes, through a different restoration in their proliferative and adipogenic potential. Weight loss induced by bariatric surgery correlates to the subcutaneous ASC functions and could explain the variability of metabolic improvement. Limited research data are available to the present and these data support the importance of diagnosis of subcutaneous ASCs functions as predictors of metabolic improvement after bariatric surgery.

scholarly journals Human Adipose Tissue Macrophages Are Enhanced but Changed to an Anti-Inflammatory Profile in Obesity

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Karen Fjeldborg ◽  
Steen B. Pedersen ◽  
Holger J. Møller ◽  
Tore Christiansen ◽  
Marianne Bennetzen ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Human Adipose Tissue ◽  
Multivariate Regression Analysis ◽  
Low Grade ◽  
Macrophage Marker ◽  
Adipose Tissue Macrophages ◽  
Obese Subjects ◽  
Anti Inflammatory ◽  
Inflammatory Profile

Objective. Adipose tissue (AT) macrophages are increased in obesity and associated with low grade inflammation. We aimed to characterize the phenotype of AT macrophages in humans in relation to obesity and insulin resistance.Design. Gene-expression levels of general macrophage markers (CD68 and CD14), proinflammatory markers/M1 (TNF-α, MCP-1, and IL-6), and anti-inflammatory markers/M2 (CD163, CD206, and IL-10) were determined by RT-PCR in subcutaneous AT samples from lean and obese subjects. Insulin resistance was determined by HOMA-IR.Results. All the macrophage markers were elevated in the AT from obese compared to lean subjects (P<0.001). To determine the phenotype of the macrophages the level of CD14 was used to adjust the total number of macrophages. The relative expression of CD163 and IL-10 was elevated, and TNF-αand IL-6 were reduced in AT from obese subjects (allP<0.05). In a multivariate regression analysis CD163 was the only macrophage marker significantly associated with HOMA-IR (β: 0.57;P<0.05). Conclusion. Obesity is associated with elevated numbers of macrophages in the AT. Unexpectedly, the macrophages change phenotype by obesity, with a preponderance of M2 and a decrement of M1 markers in AT from obese subjects. Moreover, CD163 was the only macrophage marker associated with HOMA-IR after multiple adjustments.

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