Adipose tissue: an endocrine organ playing a role in metabolic regulation

2016 ◽  
Vol 26 (1) ◽  
Author(s):  
Andrea Booth ◽  
Aaron Magnuson ◽  
Josephine Fouts ◽  
Michelle T. Foster
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Glucose Homeostasis ◽  
Insulin Signaling ◽  
Metabolic Regulation ◽  
Cell Function ◽  
Immune Cell ◽  
Whole Body ◽  
Endocrine Organ

AbstractAdipose tissue is a complex endocrine organ with an intricate role in whole body homeostasis. Beyond storing energy, adipose tissue is fundamental in numerous processes including, but not limited to, metabolism, food intake and immune cell function. Adipokines and cytokines are the signaling factors from adipose tissue. These factors play a role in maintaining health, but are also candidates for pathologies associated with obesity. Indeed excessive adiposity causes dysregulation of these factors which negatively affect health and contribute to numerous obesity-induced co-morbidities. In particular, adipokines are fundamental in regulation of glucose homeostasis and insulin signaling, thus aberrant production of these adipose derived hormones correlates with the development and progression of type 2 diabetes. Therefore, elucidation of adipose regulation is crucial for understanding the pathophysiological basis of obesity and metabolic diseases such as type 2 diabetes. In the present review, we summarize current data on the relation between adipokines and adipose depot derived cytokines in the maintenance of glucose homeostasis. Specifically, physiological and molecular functions of several adipokines are defined with particular focus on interactions within the insulin-signaling pathway and subsequent regulation of glucose uptake in both standard and obesity-induced dysregulated conditions. This same relation will be discussed for cytokines and inflammation as well.

scholarly journals Activation of Bone Marrow Adaptive Immunity in Type 2 Diabetes: Rescue by Co-stimulation Modulator Abatacept

2021 ◽  
Vol 12 ◽  
Author(s):  
Marianna Santopaolo ◽  
Niall Sullivan ◽  
Anita Coral Thomas ◽  
Valeria Vincenza Alvino ◽  
Lindsay B. Nicholson ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Bone Marrow ◽  
T Cells ◽  
Insulin Sensitivity ◽  
Adaptive Immunity ◽  
Cell Function ◽  
Immune Cell ◽  
Low Grade ◽  
Cardiac Damage

Background: Chronic low-grade inflammation and alterations in innate and adaptive immunity were reported in Type 2 diabetes (T2D). Here, we investigated the abundance and activation of T cells in the bone marrow (BM) of patients with T2D. We then verified the human data in a murine model and tested if the activation of T cells can be rescued by treating mice with abatacept, an immunomodulatory drug employed for the treatment of rheumatoid arthritis. Clinical evidence indicated abatacept can slow the decline in beta-cell function.Methods: A cohort of 24 patients (12 with T2D) undergoing hip replacement surgery was enrolled in the study. Flow cytometry and cytokine analyses were performed on BM leftovers from surgery. We next compared the immune profile of db/db and control wt/db mice. In an additional study, db/db mice were randomized to receive abatacept or vehicle for 4 weeks, with endpoints being immune cell profile, indices of insulin sensitivity, and heart performance.Results: Patients with T2D showed increased frequencies of BM CD4+ (2.8-fold, p = 0.001) and CD8+ T cells (1.8-fold, p = 0.01), with the upregulation of the activation marker CD69 and the homing receptor CCR7 in CD4+ (1.64-fold, p = 0.003 and 2.27-fold, p = 0.01, respectively) and CD8+ fractions (1.79-fold, p = 0.05 and 1.69-fold, p = 0.02, respectively). These differences were confirmed in a multivariable regression model. CCL19 (CCR7 receptor ligand) and CXCL10/11 (CXCR3 receptor ligands), implicated in T-cell migration and activation, were the most differentially modulated chemokines. Studies in mice confirmed the activation of adaptive immunity in T2D. Abatacept reduced the activation of T cells and the levels of proinflammatory cytokines and improved cardiac function but not insulin sensitivity.Conclusions: Results provide proof-of-concept evidence for the activation of BM adaptive immunity in T2D. In mice, treatment with abatacept dampens the activation of adaptive immunity and protects from cardiac damage.

scholarly journals Inflammation of adipose tissue. Part 2. Pathogenetic role in type 2 diabetes mellitus

2009 ◽  
Vol 55 (5) ◽  
pp. 43-48 ◽  
Author(s):  
V Shvarts
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Adipose Tissue ◽  
Cell Function ◽  
Signal Pathway ◽  
Insulin Signal ◽  
Kinase Cascade

This review deals with the role of adipose tissue inflammation (ATI) in the development of type 2 diabetes mellitus (DM2). ATI is regarded as a link between obesity and DM2. The review illustrates the involvement of main adipokines in pathogenesis of DM2 and provides a detailed description of such factors as impaired adiponectin and stimulation of cytokine production responsible for metabolic disorders, activation of lipolysis, in adipocytes, increased fatty acid and triglyceride levels, suppression of insulin activity at the receptor and intracellular levels. Adipokines, in the first place cytokines, act on the insulin signal pathway and affect the intracellular inflammatory kinase cascade. At the intercellular level, ATI stimulates JNK and IKK-beta/kB responsible for the development of insulin resistance via such mechanisms as activation of cytokine secretion in the adipose tissue, oxidative stress, and induction of endoplasmic reticulum enzymes. The key role of JNK and IKK-beta/kB in the inhibition of the insulin signal pathway is mediated through inactivation of insulin receptor substrate 1. Also, it is shown that ATI modulates B-cell function and promotes progressive reduction of insulin secretion.

scholarly journals Adipose Tissue-Derived Signatures for Obesity and Type 2 Diabetes: Adipokines, Batokines and MicroRNAs

2019 ◽  
Vol 8 (6) ◽  
pp. 854 ◽  
Author(s):  
Min-Woo Lee ◽  
Mihye Lee ◽  
Kyoung-Jin Oh
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Energy Homeostasis ◽  
Metabolic Disturbances ◽  
Endocrine Organ ◽  
Brown Adipose ◽  
Exosomal Mirnas ◽  
Exosomal Mirna

Obesity is one of the main risk factors for type 2 diabetes mellitus (T2DM). It is closely related to metabolic disturbances in the adipose tissue that primarily functions as a fat reservoir. For this reason, adipose tissue is considered as the primary site for initiation and aggravation of obesity and T2DM. As a key endocrine organ, the adipose tissue communicates with other organs, such as the brain, liver, muscle, and pancreas, for the maintenance of energy homeostasis. Two different types of adipose tissues—the white adipose tissue (WAT) and brown adipose tissue (BAT)—secrete bioactive peptides and proteins, known as “adipokines” and “batokines,” respectively. Some of them have beneficial anti-inflammatory effects, while others have harmful inflammatory effects. Recently, “exosomal microRNAs (miRNAs)” were identified as novel adipokines, as adipose tissue-derived exosomal miRNAs can affect other organs. In the present review, we discuss the role of adipose-derived secretory factors—adipokines, batokines, and exosomal miRNA—in obesity and T2DM. It will provide new insights into the pathophysiological mechanisms involved in disturbances of adipose-derived factors and will support the development of adipose-derived factors as potential therapeutic targets for obesity and T2DM.

scholarly journals Effects of Exenatide and Humalog Mix25 on Fat Distribution, Insulin Sensitivity, and β-Cell Function in Normal BMI Patients with Type 2 Diabetes and Visceral Adiposity

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xinlei Wang ◽  
Xiaoqin Zhao ◽  
Yunjuan Gu ◽  
Xiaohui Zhu ◽  
Tong Yin ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Blood Glucose ◽  
Insulin Sensitivity ◽  
Magnetic Resonance ◽  
Cell Function ◽  
Visceral Adiposity ◽  
Fibroblast Growth Factor 21 ◽  
Resonance Spectroscopy

In China, most normal BMI (body mass index of ≥18.5 to <25 kg/m2) adults with type 2 diabetes (T2DM) exhibit visceral adiposity. This study compared the effects of exenatide and humalog Mix25 on normal BMI patients with T2DM and visceral adiposity. A total of 95 patients were randomized to receive either exenatide or humalog Mix25 treatment for 24 weeks. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were quantified by magnetic resonance imaging (MRI) and liver fat content (LFC) by liver proton magnetic resonance spectroscopy (1H MRS). Each patient’s weight, waist circumference, BMI, blood glucose, insulin sensitivity, pancreatic β-cell function, and fibroblast growth factor 21 (FGF-21) levels were measured. Data from 81 patients who completed the study (40 and 41 in the exenatide and humalog Mix25 groups, respectively) were analysed. The change in 2 h plasma blood glucose was greater in the exenatide group (P=0.039). HOMA-IR and MBCI improved significantly after exenatide therapy (P<0.01, P=0.045). VAT and LFC decreased in both groups (P<0.01 for all) but to a greater extent in the exenatide group, while SAT only decreased with exenatide therapy (P<0.01). FGF-21 levels declined more in the exenatide group (P<0.01), but were positively correlated with VAT in the entire cohort before (r=0.244, P=0.043) and after (r=0.290, P=0.016) the intervention. The effects of exenatide on glycaemic metabolism, insulin resistance, pancreatic β-cell function, and fat deposition support its administration to normal BMI patients with T2DM and visceral adiposity.

Ketosis-Prone Type 2 Diabetes: Effect of Hyperglycemia on β-Cell Function and Skeletal Muscle Insulin Signaling

2007 ◽  
Vol 13 (3) ◽  
pp. 283-290 ◽  
Author(s):  
Guillermo Umpierrez ◽  
Dawn Smiley ◽  
Aidar Gosmanov ◽  
Donald Thomason
Keyword(s):  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Insulin Signaling ◽  
Cell Function ◽  
Β Cell ◽  
Β Cell Function

Estimation of ellagic acid and/or repaglinide effects on insulin signaling, oxidative stress, and inflammatory mediators of liver, pancreas, adipose tissue, and brain in insulin resistant/type 2 diabetic rats

2017 ◽  
Vol 42 (2) ◽  
pp. 181-192 ◽  
Author(s):  
Mohamed M. Amin ◽  
Mahmoud S. Arbid
Keyword(s):  
Type 2 Diabetes ◽  
Body Weight ◽  
Adipose Tissue ◽  
Insulin Signaling ◽  
Inflammatory Mediators ◽  
Ellagic Acid ◽  
Molecular Mechanisms ◽  
Combined Treatment ◽  
Albino Rats

Even though ellagic acid has previously been valued in many models of cancer, so far its full mechanistic effect as a natural antiapoptotic agent in the prevention of type 2 diabetes complications has not been completely elucidated, which was the goal of this study. We fed albino rats a high-fat fructose diet (HFFD) for 2 months to induce insulin resistance/type 2 diabetes and then treated the rats with ellagic acid (10 mg/kg body weight, orally) and/or repaglinide (0.5 mg/kg body weight, orally) for 2 weeks. At the serum level, ellagic acid challenged the consequences of HFFD, significantly improving the glucose/insulin balance, liver enzymes, lipid profile, inflammatory cytokines, redox level, adipokines, ammonia, and manganese. At the tissue level (liver, pancreas, adipose tissue, and brain), ellagic acid significantly enhanced insulin signaling, autophosphorylation, adiponectin receptors, glucose transporters, inflammatory mediators, and apoptotic markers. Remarkably, combined treatment with both ellagic acid and repaglinide had a more pronounced effect than treatment with either alone. These outcomes give new insight into the promising molecular mechanisms by which ellagic acid modulates numerous factors induced in the progression of diabetes.

scholarly journals Adipose tissue immune cells in obesity, type 2 diabetes mellitus and cardiovascular diseases

2021 ◽  
Author(s):  
Anna Cinkajzlová ◽  
Milos Mraz ◽  
Martin Haluzik
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Adipose Tissue ◽  
Cardiovascular Diseases ◽  
Immune Cells ◽  
Immune Cell ◽  
Current Knowledge ◽  
Systemic Circulation

Immune cells are an inseparable component of adipose tissue intimately involved in most of its functions. Physiologically, they regulate adipose tissue homeostasis, while in case of adipose tissue stress immune cells are able to change their phenotype, enhance their count and subsequently contribute to the development and maintenance of local adipose tissue inflammation. Immune cells are an important source of inflammatory cytokines and other pro-inflammatory products that further influence not only surrounding tissues, but via systemic circulation also the whole organism being thus one of the main factors responsible for the transition from simple obesity to associated metabolic and cardiovascular complications. The purpose of this review is to summarize current knowledge on different adipose tissue immune cell subsets and their role in the development of obesity, type 2 diabetes mellitus and cardiovascular diseases.

scholarly journals Deletion of GPR21 improves glucose homeostasis and inhibits the CCL2-CCR2 axis by divergent mechanisms

2021 ◽  
Vol 9 (2) ◽  
pp. e002285
Author(s):  
Darren M Riddy ◽  
Helene L Kammoun ◽  
Andrew J Murphy ◽  
Sanja Bosnyak-Gladovic ◽  
Rocio De la Fuente Gonzalez ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Glucose Homeostasis ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
High Fat ◽  
Peripheral Blood Mononuclear ◽  
Monocyte Migration ◽  
Genotypic Analysis ◽  
Fat Feeding

IntroductionA potential role for the orphan G protein-coupled receptor, GPR21, in linking immune cell infiltration into tissues and obesity-induced insulin resistance has been proposed, although limited studies in mice are complicated by non-selective deletion of Gpr21.Research design and methodsWe hypothesized that a Gpr21-selective knockout mouse model, coupled with type 2 diabetes patient samples, would clarify these issues and enable clear assessment of GPR21 as a potential therapeutic target.ResultsHigh-fat feeding studies in Gpr21−/− mice revealed improved glucose tolerance and modest changes in inflammatory gene expression. Gpr21−/− monocytes and intraperitoneal macrophages had selectively impaired chemotactic responses to monocyte chemoattractant protein (MCP)-1, despite unaltered expression of Ccr2. Further genotypic analysis revealed that chemotactic impairment was due to dysregulated monocyte polarization. Patient samples revealed elevated GPR21 expression in peripheral blood mononuclear cells in type 2 diabetes, which was correlated with both %HbA1c and fasting plasma glucose levels.ConclusionsCollectively, human and mouse data suggest that GPR21 influences both glucose homeostasis and MCP-1/CCL2-CCR2-driven monocyte migration. However, a Gpr21−/− bone marrow transplantation and high-fat feeding study in mice revealed no effect on glucose homeostasis, suggesting that there is no (or limited) overlap in the mechanism involved for monocyte-driven inflammation and glucose homeostasis.

scholarly journals Tetrahydrocurcumin Upregulates the Adiponectin-AdipoR Pathway and Improves Insulin Signaling and Pancreatic β-Cell Function in High-Fat Diet/Streptozotocin-Induced Diabetic Obese Mice

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4552
Author(s):  
Yi-Zhen Tsai ◽  
Mei-Ling Tsai ◽  
Li-Yin Hsu ◽  
Chi-Tang Ho ◽  
Ching-Shu Lai
Keyword(s):  
Type 2 Diabetes ◽  
Insulin Signaling ◽  
High Fat Diet ◽  
Cell Function ◽  
Obese Mice ◽  
High Fat ◽  
Islet Mass ◽  
Beneficial Effects ◽  
Β Cell Function

Impairment of adiponectin production and function is closely associated with insulin resistance and type 2 diabetes, which are linked to obesity. Studies in animal models have documented the anti-diabetic effects of tetrahydrocurcumin (THC). Although several possible mechanisms have been proposed, the contribution of adiponectin signaling on THC-mediated antihyperglycemic effects remains unknown. Here, we report that adiposity, steatosis, and hyperglycemia were potently attenuated in high-fat diet/streptozotocin-induced diabetic obese mice after they received 20 and 100 mg/kg THC for 14 weeks. THC upregulated UCP-1 in adipose tissue and elevated adiponectin levels in the circulation. THC upregulated the AdipoR1/R2-APPL1-mediated pathway in the liver and skeletal muscle, which contributes to improved insulin signaling, glucose utilization, and lipid metabolism. Furthermore, THC treatment significantly (p < 0.05) preserved islet mass, reduced apoptosis, and restored defective insulin expression in the pancreatic β-cells of diabetic obese mice, which was accompanied by an elevation of AdipoR1 and APPL1. These results demonstrated a potential mechanism underlying the beneficial effects of THC against hyperglycemia via the adiponectin-AdipoR pathway, and thus, may lead to a novel therapeutic use for type 2 diabetes.

scholarly journals Single-Cell Analysis of the Periodontal Immune Niche in Type 2 Diabetes

2020 ◽  
Vol 99 (7) ◽  
pp. 855-862
Author(s):  
A.C. Belkina ◽  
M. Azer ◽  
J.J. Lee ◽  
H.H. Elgaali ◽  
R. Pihl ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Flow Cytometry ◽  
Cell Function ◽  
Immune Cell ◽  
T Cell Subsets ◽  
Common Source ◽  
Immune Cell Function ◽  
Periodontal Inflammation ◽  
Increased Risk

Periodontitis (PD) is a common source of uncontrolled inflammation in obesity-associated type 2 diabetes (T2D). PD apparently fuels the inflammation of T2D and associates with poor glycemic control and increased T2D morbidity. New therapeutics are critically needed to counter the sources of periodontal infection and inflammation that are accelerated in people with T2D. The precise mechanisms underlying the relationship between PD and T2D remain poorly understood. Every major immune cell subset has been implicated in the unresolved inflammation of PD, regardless of host metabolic health. However, analyses of inflammatory cells in PD with human periodontal tissue have generally focused on mRNA quantification and immunohistochemical analyses, both of which provide limited information on immune cell function. We used a combination of flow cytometry for cell surface markers and enzyme-linked immunospot methods to assess the subset distribution and function of immune cells isolated from gingiva of people who had PD and were systemically healthy, had PD and T2D (PD/T2D), or, for flow cytometry, were systemically and orally healthy. T-cell subsets dominated the cellular immune compartment in gingiva from all groups, and B cells were relatively rare. Although immune cell frequencies were similar among groups, a higher proportion of CD11b+ or CD4+ cells secreted IFNγ/IL-10 or IL-8, respectively, in cells from PD/T2D samples as compared with PD-alone samples. Our data indicate that fundamental differences in gingival immune cell function between PD and T2D-potentiated PD may account for the increased risk and severity of PD in subjects with T2D. Such differences may suggest unexpected therapeutic targets for alleviating periodontal inflammation in people with T2D.

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