scholarly journals Subacute Endotoxemia Induces Adipose Inflammation and Changes in Lipid and Lipoprotein Metabolism in Cats

Endocrinology ◽  
2011 ◽  
Vol 152 (3) ◽  
pp. 804-815 ◽  
Author(s):  
M. Osto ◽  
E. Zini ◽  
M. Franchini ◽  
C. Wolfrum ◽  
F. Guscetti ◽  
...  

Acute inflammation in humans is associated with transient insulin resistance (IR) and dyslipidemia. Chronic low-grade inflammation is a pathogenic component of IR and adipose tissue dysfunction in obesity-induced type 2 diabetes. Because feline diabetes closely resembles human type 2 diabetes, we studied whether lipopolysaccharide (LPS)-induced subacute inflammation, in the absence of obesity, is the potential primary cause of IR and metabolic disorders. Cats received increasing iv doses (10–1000 ng/kg−1 · h−1) of LPS (n = 5) or saline (n = 5) for 10 d. Body temperature, proinflammatory and metabolic markers, and insulin sensitivity were measured daily. Tissue mRNA and protein expression were quantified on d 10. LPS infusion increased circulating and tissue markers of inflammation. Based on the homeostasis model assessment, endotoxemia induced transient IR and β-cell dysfunction. At the whole-body level, IR reverted after the 10-d treatment; however, tissue-specific indications of IR were observed, such as down-regulation of adipose glucose transporter 4, hepatic peroxisome proliferative activated receptor-γ1 and -2, and muscle insulin receptor substrate-1. In adipose tissue, increased hormone-sensitive lipase activity led to reduced adipocyte size, concomitant with increased plasma and hepatic triglyceride content and decreased total and high-density lipoprotein cholesterol levels. Prolonged LPS-induced inflammation caused acute IR, followed by long-lasting tissue-specific dysfunctions of lipid-, glucose-, and insulin metabolism-related targets; this ultimately resulted in dyslipidemia but not whole-body IR. Endotoxemia in cats may provide a promising model to study the cross talk between metabolic and inflammatory responses in the development of adipose tissue dysfunction and IR.

2018 ◽  
Vol 315 (6) ◽  
pp. E1242-E1250 ◽  
Author(s):  
Donghua Hu ◽  
Ryan D. Russell ◽  
Devika Remash ◽  
Timothy Greenaway ◽  
Stephen Rattigan ◽  
...  

The microcirculation in adipose tissue is markedly impaired in type 2 diabetes (T2D). Resistance training (RT) often increases muscle mass and promotes a favorable metabolic profile in people with T2D, even in the absence of fat loss. Whether the metabolic benefits of RT in T2D are linked to improvements in adipose tissue microvascular blood flow is unknown. Eighteen sedentary people with T2D (7 women/11 men, 52 ± 7 yr) completed 6 wk of RT. Before and after RT, overnight-fasted participants had blood sampled for clinical chemistries (glucose, insulin, lipids, HbA1c, and proinflammatory markers) and underwent an oral glucose challenge (OGC; 50 g glucose × 2 h) and a DEXA scan to assess body composition. Adipose tissue microvascular blood volume and flow were assessed at rest and 1 h post-OGC using contrast-enhanced ultrasound. RT significantly reduced fasting blood glucose ( P = 0.006), HbA1c ( P = 0.007), 2-h glucose area under the time curve post-OGC ( P = 0.014), and homeostatic model assessment of insulin resistance ( P = 0.005). This was accompanied by a small reduction in total body fat ( P = 0.002), trunk fat ( P = 0.023), and fasting triglyceride levels ( P = 0.029). Lean mass ( P = 0.003), circulating TNF-α ( P = 0.006), and soluble VCAM-1 ( P < 0.001) increased post-RT. There were no significant changes in adipose tissue microvascular blood volume or flow following RT; however those who did have a higher baseline microvascular blood flow post-RT also had lower fasting triglyceride levels ( r = −0.476, P = 0.045). The anthropometric, glycemic, and insulin-sensitizing benefits of 6 wk of RT in people with T2D are not associated with an improvement in adipose tissue microvascular responses; however, there may be an adipose tissue microvascular-linked benefit to fasting triglyceride levels.


2012 ◽  
Vol 167 (4) ◽  
pp. 569-578 ◽  
Author(s):  
Francisco J Ortega ◽  
Mónica Sabater ◽  
José M Moreno-Navarrete ◽  
Neus Pueyo ◽  
Patricia Botas ◽  
...  

ObjectiveIncreased circulating calprotectin has been reported in obese subjects but not in association with measures of insulin resistance and type 2 diabetes (T2D). The main aim of this study was to determine whether calprotectins in plasma and urine are associated with insulin resistance.DesignWe performed both cross-sectional and longitudinal (diet-induced weight loss) studies.MethodsCirculating calprotectin concentrations (ELISA), other inflammatory markers, homeostasis model assessment of insulin resistance (HOMA-IR), and parameters of glucose and lipid metabolism were evaluated in 298 subjects (185 with normal (NGT) and 62 with impaired (IGT) glucose tolerance and 51 T2D subjects). Calprotectin was also evaluated in urine samples from 71 participants (50 NGT and 21 subjects with IGT). Insulin sensitivity (SI, Minimal Model) was determined in a subset of 156 subjects, and the effects of weight loss were investigated in an independent cohort of obese subjects (n=19).ResultsCirculating calprotectin was significantly increased in IGT–T2D (independently of BMI) and positively associated with HOMA-IR, obesity measures, inflammatory markers, and parameters of glucose and lipid metabolism. Similar findings were reported for calprotectin concentrations in urine. In the subset of subjects, the association of calprotectin withSIwas independent of BMI and age. In fact,SItogether with C-reactive protein contributed to 27.4% of calprotectin variance after controlling for age and blood neutrophils count. Otherwise, weight loss led to decreased circulating calprotectin in parallel to fasting glucose and HOMA-IR.ConclusionThese findings suggest that circulating and urinary concentrations of calprotectin are linked to chronic low-grade inflammation and insulin resistance beyond obesity.


2006 ◽  
Vol 92 (2) ◽  
pp. 386-395 ◽  
Author(s):  
Arya M. Sharma ◽  
Bart Staels

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.


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 ◽  
...  

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Miloš Mráz ◽  
Anna Cinkajzlová ◽  
Jana Kloučková ◽  
Zdeňka Lacinová ◽  
Helena Kratochvílová ◽  
...  

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.


Author(s):  
Marisa de Carvalho BORGES ◽  
Guilherme Azevedo TERRA ◽  
Tharsus Dias TAKEUTI ◽  
Betânia Maria RIBEIRO ◽  
Alex Augusto SILVA ◽  
...  

Background: Immunological and inflammatory mechanisms play a key role in the development and progression of type 2 diabetes mellitus. Aim: To raise the hypothesis that alterations in immunological parameters occur after duodenojejunal bypass surgery combined with ileal interposition without gastrectomy, and influences the insulin metabolism of betacells. Methods: Seventeen patients with type 2 diabetes mellitus under clinical management were submitted to surgery and blood samples were collected before and six months after surgery for evaluation of the serum profile of proinflammatory (IFN-γ, TNF-α, IL-17A) and anti-inflammatory cytokines (IL-4, IL-10). In addition, anthropometric measures, glucose levels and insulin use were evaluated in each patient. Results: No changes in the expression pattern of proinflammatory cytokines were observed before and after surgery. In contrast, there was a significant decrease in IL-10 expression, which coincided with a reduction in the daily insulin dose, glycemic index, and BMI of the patients. Early presentation of food to the ileum may have induced the production of incretins such as GLP-1 and PYY which, together with glycemic control, contributed to weight loss, diabetes remission and the consequent good surgical prognosis of these patients. In addition, the control of metabolic syndrome was responsible for the reduction of IL-10 expression in these patients. Conclusion: These findings suggest the presence of low-grade inflammation in these patients during the postoperative period, certainly as a result of adequate glycemic control and absence of obesity, contributing to a good outcome of surgery.


2014 ◽  
Vol 5 (9) ◽  
pp. 2120-2128 ◽  
Author(s):  
Ana Laura de la Garza ◽  
Usune Etxeberria ◽  
Sara Palacios-Ortega ◽  
Alexander G. Haslberger ◽  
Eva Aumueller ◽  
...  

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.


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