scholarly journals Brown Fat Lipoatrophy and Increased Visceral Adiposity through a Concerted Adipocytokines Overexpression Induces Vascular Insulin Resistance and Dysfunction

Endocrinology ◽  
2012 ◽  
Vol 153 (3) ◽  
pp. 1242-1255 ◽  
Author(s):  
Almudena Gómez-Hernández ◽  
Yolanda F. Otero ◽  
Natalia de las Heras ◽  
Óscar Escribano ◽  
Victoria Cachofeiro ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Vascular Dysfunction ◽  
Nuclear Factor Κb ◽  
Brown Fat ◽  
Visceral Adiposity ◽  
Inflammatory Activity ◽  
Nuclear Factor ◽  
Antibody Treatment ◽  
Tnf Α

In this study, we analyzed the role played by concerted expression of adipocytokines associated with brown fat lipoatrophy and increased visceral adiposity on triggering vascular insulin resistance and dysfunction in brown adipose tissue (BAT) insulin receptor knockout (BATIRKO) mice. In addition, we assessed whether vascular insulin resistance may aggravate vascular damage. The 52-wk-old, but not 33-wk-old, BATIRKO mice had a significant decrease of BAT mass associated with a significant increase of visceral white adipose tissue (WAT) mass, without changes in body weight. Brown fat lipoatrophy and increased visceral adiposity enhanced the concerted expression of adipocytokines (TNF-α, leptin, and plasminogen activator inhibitor 1) and nuclear factor-κB binding activity in BAT and visceral WAT, mainly in the gonadal depot, and aorta. Although those mice showed insulin sensitivity in the liver and skeletal muscle, insulin signaling in WAT (gonadal depot) and aorta was markedly impaired. Treatment with anti-TNF-α antibody impaired the inflammatory activity in visceral adipose tissue, attenuated insulin resistance in WAT and aorta and induced glucose tolerance. Finally, 52-wk-old BATIRKO mice showed vascular dysfunction, macrophage infiltration, oxidative stress, and a significant increase of gene markers of endothelial activation and inflammation, the latter effect being totally reverted by anti-TNF-α antibody treatment. Our results suggest that brown fat lipoatrophy and increased visceral adiposity through the concerted overexpression of cytoadipokines induces nuclear factor-κB-mediated inflammatory signaling, vascular insulin resistance, and vascular dysfunction. Inhibition of inflammatory activity by anti-TNF-α antibody treatment attenuates vascular insulin resistance and impairs gene expression of vascular dysfunction markers.

scholarly journals Sulfasalazine and BAY 11-7082 Interfere with the Nuclear Factor-κB and IκB Kinase Pathway to Regulate the Release of Proinflammatory Cytokines from Human Adipose Tissue and Skeletal Muscle in Vitro

Endocrinology ◽  
2005 ◽  
Vol 146 (3) ◽  
pp. 1491-1497 ◽  
Author(s):  
Martha Lappas ◽  
Kirin Yee ◽  
Michael Permezel ◽  
Gregory E. Rice
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Human Adipose Tissue ◽  
Nuclear Factor Κb ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Iκb Kinase ◽  
Β Protein ◽  
Tnf Α

There is much evidence to indicate a role for adipocytokines in insulin resistance and/or type 2 diabetes mellitus. In experimental models, oral salicylates, through their ability to interfere with the nuclear factor-κB (NF-κB) transcription pathway, have been demonstrated to reverse insulin resistance. The aim of this study was to investigate whether NF-κB regulates the release of adipocytokines in human adipose tissue and skeletal muscle. Human sc adipose tissue and skeletal muscle (obtained from normal pregnant women) were incubated in the absence (control) or presence of two NF-κB inhibitors sulfasalazine (1.25, 2.5, and 5 mm) and BAY 11-7082 (25, 50, and 100 μm). After an 18-h incubation, the tissues were collected, and NF-κB p65 DNA-binding activity and IκB kinase (IKK-β) and insulin receptor-β protein expression were assessed by ELISA and Western blotting, respectively. The incubation medium was collected, and the release of TNF-α, IL-6, IL-8, resistin, adiponectin, and leptin was quantified by ELISA. Treatment of adipose tissue and skeletal muscle with sulfasalazine and BAY 11-7082 significantly inhibited the release of IL-6, IL-8, and TNF-α; NF-κB p65 DNA-binding activity; and IKK-β protein expression (P < 0.05, by Newman-Keuls test). There was no effect of sulfasalazine and BAY 11-7082 on resistin, adiponectin, or leptin release. Both sulfasalazine and BAY 11-7082 increased the adipose tissue and skeletal muscle expression of insulin receptor-β. The data presented in this study demonstrate that the IKK-β/NF-κB transcription pathway is a key regulator of IL-6, IL-8, and TNF-α release from adipose tissue and skeletal muscle. Control of the IKK-β/NF-κB pathway may therefore provide an alternative therapeutic strategy for regulating aberrant cytokine release and thereby alleviating insulin resistance in type 2 diabetes mellitus.

A direct requirement of nuclear factor-κB for suppression of apoptosis in ventricular myocytes

2000 ◽  
Vol 279 (3) ◽  
pp. H939-H945 ◽  
Author(s):  
Shareef Mustapha ◽  
Alla Kirshner ◽  
Danielle De Moissac ◽  
Lorrie A. Kirshenbaum
Keyword(s):  
Dna Binding ◽  
Gene Transcription ◽  
Ventricular Myocytes ◽  
Vital Staining ◽  
Fold Increase ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Cytoplasmic Factor ◽  
Tnf Α ◽  
Factor Α

Nuclear factor-κB (NF-κB) is a ubiquitously expressed cellular factor regulated by the cytoplasmic factor inhibitor protein κBα (IκBα). Activation of NF-κB by cytokines, including tumor necrosis factor-α (TNF-α), requires the phosphorylation and degradation of IκBα. An anti-apoptotic role for NF-κB has recently been suggested. In the present study, we ascertained whether death-promoting signals and apoptosis mediated by TNF-α are suppressed by NF-κB in postnatal ventricular myocytes. Stimulation of myocytes with TNF-α resulted in a 12.1-fold increase ( P < 0.01) in NF-κB-dependent gene transcription and DNA binding compared with controls. This was accompanied by a corresponding increase in the NF-κB target protein A20 as determined by Western blot analysis. Vital staining revealed that TNF-α was not cytotoxic to myocytes and did not provoke apoptosis. Adenovirus-mediated delivery of a nonphosphorylatable form of IκBα to inactivate NF-κB prevented TNF-α-stimulated NF-κB-dependent gene transcription and nuclear NF-κB DNA binding. Importantly, myocytes stimulated with TNF-α and defective for NF-κB activation resulted in a 2.2-fold increase ( P < 0.001) in apoptosis. To our knowledge, the data provide the first indication that a functional NF-κB signaling pathway is crucial for suppressing death-promoting signals mediated by TNF-α in ventricular myocytes.

scholarly journals Activation of Nuclear Factor κb and bcl-x Survival Gene Expression by Nerve Growth Factor Requires Tyrosine Phosphorylation of IκBα

2001 ◽  
Vol 152 (4) ◽  
pp. 753-764 ◽  
Author(s):  
Nguyen Truc Bui ◽  
Antonia Livolsi ◽  
Jean-Francois Peyron ◽  
Jochen H.M. Prehn
Keyword(s):  
Gene Expression ◽  
Tyrosine Phosphorylation ◽  
Fluorescent Protein ◽  
Nuclear Translocation ◽  
Nuclear Factor Κb ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Nuclear Factor ◽  
Human Neuroblastoma ◽  
Tnf Α

NGF has been shown to support neuron survival by activating the transcription factor nuclear factor-κB (NFκB). We investigated the effect of NGF on the expression of Bcl-xL, an anti–apoptotic Bcl-2 family protein. Treatment of rat pheochromocytoma PC12 cells, human neuroblastoma SH-SY5Y cells, or primary rat hippocampal neurons with NGF (0.1–10 ng/ml) increased the expression of bcl-xL mRNA and protein. Reporter gene analysis revealed a significant increase in NFκB activity after treatment with NGF that was associated with increased nuclear translocation of the active NFκB p65 subunit. NGF-induced NFκB activity and Bcl-xL expression were inhibited in cells overexpressing the NFκB inhibitor, IκBα. Unlike tumor necrosis factor-α (TNF-α), however, NGF-induced NFκB activation occurred without significant degradation of IκBs determined by Western blot analysis and time-lapse imaging of neurons expressing green fluorescent protein–tagged IκBα. Moreover, in contrast to TNF-α, NGF failed to phosphorylate IκBα at serine residue 32, but instead caused significant tyrosine phosphorylation. Overexpression of a Y42F mutant of IκBα potently suppressed NFG-, but not TNF-α–induced NFκB activation. Conversely, overexpression of a dominant negative mutant of TNF receptor-associated factor-6 blocked TNF-α–, but not NGF-induced NFκB activation. We conclude that NGF and TNF-α induce different signaling pathways in neurons to activate NFκB and bcl-x gene expression.

scholarly journals Developmental androgen excess programs sympathetic tone and adipose tissue dysfunction and predisposes to a cardiometabolic syndrome in female mice

2013 ◽  
Vol 304 (12) ◽  
pp. E1321-E1330 ◽  
Author(s):  
Kazunari Nohara ◽  
Rizwana S. Waraich ◽  
Suhuan Liu ◽  
Mathieu Ferron ◽  
Aurélie Waget ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Glucose Intolerance ◽  
Adult Female ◽  
Sympathetic Tone ◽  
Visceral Adiposity ◽  
Androgen Excess ◽  
Altered Expression ◽  
Female Mice ◽  
The Impact

Among women, the polycystic ovarian syndrome (PCOS) is considered a form of metabolic syndrome with reproductive abnormalities. Women with PCOS show increased sympathetic tone, visceral adiposity with enlarged adipocytes, hypoadiponectinemia, insulin resistance, glucose intolerance, increased inactive osteocalcin, and hypertension. Excess fetal exposure to androgens has been hypothesized to play a role in the pathogenesis of PCOS. Previously, we showed that neonatal exposure to the androgen testosterone (NT) programs leptin resistance in adult female mice. Here, we studied the impact of NT on lean and adipose tissues, sympathetic tone in cardiometabolic tissues, and the development of metabolic dysfunction in mice. Neonatally androgenized adult female mice (NTF) displayed masculinization of lean tissues with increased cardiac and skeletal muscle as well as kidney masses. NTF mice showed increased and dysfunctional white adipose tissue with increased sympathetic tone in both visceral and subcutaneous fat as well as increased number of enlarged and insulin-resistant adipocytes that displayed altered expression of developmental genes and hypoadiponectinemia. NTF exhibited dysfunctional brown adipose tissue with increased mass and decreased energy expenditure. They also displayed decreased undercarboxylated and active osteocalcin and were predisposed to obesity during chronic androgen excess. NTF showed increased renal sympathetic tone associated with increased blood pressure, and they developed glucose intolerance and insulin resistance. Thus, developmental exposure to testosterone in female mice programs features of cardiometabolic dysfunction, as can be observed in women with PCOS, including increased sympathetic tone, visceral adiposity, insulin resistance, prediabetes, and hypertension.

scholarly journals (–)-Loliolide Isolated from Sargassum horneri Suppressed Oxidative Stress and Inflammation by Activating Nrf2/HO-1 Signaling in IFN-γ/TNF-α-Stimulated HaCaT Keratinocytes

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 856
Author(s):  
Eui-Jeong Han ◽  
Ilekuttige Priyan Shanura Fernando ◽  
Hyun-Soo Kim ◽  
Dae-Sung Lee ◽  
Areum Kim ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nuclear Factor Κb ◽  
Sargassum Horneri ◽  
Mitogen Activated Protein Kinase ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nuclear Factor ◽  
Hacat Keratinocytes ◽  
Tnf Α ◽  
Ifn Γ

The present study evaluated the effects of (–)-loliolide isolated from Sargassum horneri (S. horneri) against oxidative stress and inflammation, and its biological mechanism in interferon (IFN)-γ/tumor necrosis factor (TNF)-α-stimulated HaCaT keratinocytes. The results showed that (–)-loliolide improved the cell viability by reducing the production of intracellular reactive oxygen species (ROS) in IFN-γ/TNF-α-stimulated HaCaT keratinocytes. In addition, (–)-loliolide effectively decreased the expression of inflammatory cytokines (interleukin (IL)-4 IL-6, IL-13, IFN-γ and TNF-α) and chemokines (CCL11 (Eotaxin), macrophage-derived chemokine (MDC), regulated on activation, normal T cell expressed and secreted (RANTES), and thymus and activation-regulated chemokine (TARC)), by downregulating the expression of epidermal-derived initial cytokines (IL-25, IL-33 and thymic stromal lymphopoietin (TSLP)). Furthermore, (–)-loliolide suppressed the activation of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling, whereas it activated nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Interestingly, the cytoprotective effects of (–)-loliolide against IFN-γ/TNF-α stimulation were significantly blocked upon inhibition of HO-1. Taken together, these results suggest that (–)-loliolide effectively suppressed the oxidative stress and inflammation by activating the Nrf2/HO-1 signaling in IFN-γ/TNF-α-stimulated HaCaT keratinocytes.

scholarly journals Adiponectin and other Adipocytokines as Predictors of Markers of Triglyceride-Rich Lipoprotein Metabolism

2005 ◽  
Vol 51 (3) ◽  
pp. 578-585 ◽  
Author(s):  
Dick C Chan ◽  
Gerald F Watts ◽  
Theodore WK Ng ◽  
Yoshiaki Uchida ◽  
Naohiko Sakai ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Independent Predictor ◽  
Lipoprotein Metabolism ◽  
Bioelectrical Impedance ◽  
Apo B ◽  
Nonesterified Fatty Acids ◽  
Plasma Adiponectin ◽  
Tnf Α ◽  
Triglyceride Rich Lipoprotein

Abstract Background: Adipocytokines are bioactive peptides that may play an important role in the regulation of glucose and lipid metabolism. In this study, we investigated the association of plasma adipocytokine concentrations with markers of triglyceride-rich lipoprotein (TRL) metabolism in men. Methods: Fasting adiponectin, leptin, resistin, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), apolipoprotein (apo) B-48, apo C-III, and remnant-like particle (RLP)-cholesterol concentrations were measured by immunoassays and insulin resistance by homeostasis assessment (HOMA) score in 41 nondiabetic men with a body mass index of 22–35 kg/m2. Visceral and subcutaneous adipose tissue masses (ATMs) were determined by magnetic resonance imaging and total ATM by bioelectrical impedance. Results: In univariate regression, plasma adiponectin and leptin concentrations were inversely and directly associated with plasma apoB-48, apoC-III, RLP-cholesterol, triglycerides, VLDL-apoB, and VLDL-triglycerides (P &lt;0.05). Resistin, IL-6, and TNF-α were not significantly associated with any of these variables, except for a direct correction between apoC-III and IL-6 (P &lt;0.05). In multivariate regression including HOMA, age, nonesterified fatty acids, and adipose tissue compartment, adiponectin was an independent predictor of plasma apoB-48 (β coefficient = −0.354; P = 0.048), apoC-III (β coefficient = −0.406; P = 0.012), RLP-cholesterol (β coefficient = −0.377; P = 0.016), and triglycerides (β coefficient = −0.374; P = 0.013). By contrast, leptin was not an independent predictor of these TRL markers. Plasma apoB-48, apoC-III, RLP-cholesterol, and triglycerides were all significantly and positively associated with plasma insulin, HOMA, and visceral, subcutaneous, and total ATMs (P &lt;0.05). Conclusions: These data suggest that the plasma adiponectin concentration may not only link abdominal fat, insulin resistance, and dyslipidemia, but may also exert an independent role in regulating TRL metabolism.

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