scholarly journals The cat as a model for human obesity: insights into depot-specific inflammation associated with feline obesity

2013 ◽  
Vol 110 (7) ◽  
pp. 1326-1335 ◽  
Author(s):  
H. Van de Velde ◽  
G. P. J. Janssens ◽  
H. de Rooster ◽  
I. Polis ◽  
I. Peters ◽  
...  

According to human research, the location of fat accumulation seems to play an important role in the induction of obesity-related inflammatory complications. To evaluate whether an inflammatory response to obesity depends on adipose tissue location, adipokine gene expression, presence of immune cells and adipocyte cell size of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were compared between lean and obese cats. Additionally, the present study proposes the cat as a model for human obesity and highlights the importance of animal models for human research. A total of ten chronically obese and ten lean control cats were included in the present study. Body weight, body condition score and body composition were determined. T-lymphocyte, B-lymphocyte, macrophage concentrations and adipocyte cell size were measured in adipose tissue at different locations. Serum leptin concentration and the mRNA expression of leptin and adiponectin, monocyte chemoattractant protein-1, chemoligand-5, IL-8, TNF-α, interferon-γ, IL-6 and IL-10 were measured in blood and adipose tissues (abdominal and inguinal SAT, and omental, bladder and renal VAT). Feline obesity was characterised by increased adipocyte cell size and altered adipokine gene expression, in favour of pro-inflammatory cytokines and chemokines. Consequently, concentration of T-lymphocytes was increased in the adipose tissue of obese cats. Alteration of adipose tissue was location dependent in both lean and obese cats. Moreover, the observed changes were more prominent in SAT compared with VAT.

2007 ◽  
Vol 92 (7) ◽  
pp. 2688-2695 ◽  
Author(s):  
Giuseppe Murdolo ◽  
Ann Hammarstedt ◽  
Madeléne Sandqvist ◽  
Martin Schmelz ◽  
Christian Herder ◽  
...  

Abstract Context: The chemokine monocyte chemoattractant protein-1 (MCP-1) is implicated in obesity-associated chronic inflammation, insulin resistance, and atherosclerosis. Objectives: The objectives of this study were to: 1) characterize the interstitial levels and the gene expression of MCP-1 in the sc abdominal adipose tissue (SCAAT), 2) elucidate the response of MCP-1 to acute hyperinsulinemia, and 3) determine the relationship between MCP-1 and arterial stiffness. Design: Nine lean (L) and nine uncomplicated obese (OB) males were studied in the fasting state and during a euglycemic-hyperinsulinemic clamp combined with the microdialysis technique. Interstitial and serum MCP-1 (iMCP-1 and sMCP-1, respectively) levels, pulse wave analysis, and SCAAT biopsies were characterized at baseline and after hyperinsulinemia. Results: OB showed elevated sMCP-1 (P < 0.01) but similar iMCP-1 levels as compared with L. Basal iMCP-1 concentrations were considerably higher than sMCP-1 (P < 0.0001), and a gradient between iMCP-1 and sMCP-1 levels was maintained throughout the hyperinsulinemia. At baseline, SCAAT gene expression profile revealed a “co-upregulation” of MCP-1, MCP-2, macrophage inflammatory protein-1α, and CD68 in OB, and whole-body glucose disposal inversely correlated with the MCP-1 gene expression. After hyperinsulinemia, MCP-1 and MCP-2 mRNA levels significantly increased in L, but not in OB. Finally, sMCP-1 excess in the OB positively correlated with the stiffer vasculature. Conclusions: These observations demonstrate similar interstitial concentrations and a differential gene response to hyperinsulinemia of MCP-1 in the SCAAT from L and OB individuals. In human obesity, we suggest the SCAAT MCP-1 gene overexpression as a biomarker of an “inflamed” adipose organ and impaired glucose metabolism.


2006 ◽  
Vol 291 (4) ◽  
pp. E771-E778 ◽  
Author(s):  
Kyoichiro Tsuchiya ◽  
Takanobu Yoshimoto ◽  
Yuki Hirono ◽  
Toru Tateno ◽  
Toru Sugiyama ◽  
...  

Both monocyte chemoattractant protein-1 (MCP-1), a member of chemokine family, and angiotensinogen, a precursor of angiotensin (ANG) II, are produced by adipose tissue and increased in obese state. MCP-1 has been shown to decrease insulin-stimulated glucose uptake and several adipogenic genes expression in adipocytes in vitro, suggesting its pathophysiological significance in obesity. However, the pathophysiological interaction between MCP-1 and ANG II in adipose tissue remains unknown. The present study was undertaken to investigate the potential mechanisms by which ANG II affects MCP-1 gene expression in rat primary cultured preadipocytes and adipose tissue in vivo. ANG II significantly increased steady-state MCP-1 mRNA levels in a time- and dose-dependent manner. The ANG II-induced MCP-1 mRNA and protein expression was completely abolished by ANG II type 1 (AT1)-receptor antagonist (valsartan). An antioxidant/NF-κB inhibitor (pyrrolidine dithiocarbamate) and an inhibitor of 1κB-α phosphorylation (Bay 11-7085) also blocked ANG II-induced MCP-1 mRNA expression. ANG II induced translocation of NF-κB p65 subunit from cytoplasm to nucleus by immunocytochemical study. Luciferase assay using reporter constructs containing MCP-1 promoter region revealed that two NF-κB binding sites in its enhancer region were essential for the ANG II-induced promoter activities. Furthermore, basal mRNA and protein of MCP-1 during preadipocyte differentiation were significantly greater in preadipocytes than in differentiated adipocytes, whose effect was more pronounced in the presence of ANG II. Exogenous administration of ANG II to rats led to increased MCP-1 expression in epididymal, subcutaneous, and mesenteric adipose tissue. In conclusion, our present study demonstrates that ANG II increases MCP-1 gene expression via ANG II type 1 receptor-mediated and NF-κB-dependent pathway in rat preadipocytes as well as adipose MCP-1 expression in vivo. Thus the augmented MCP-1 expression by ANG II in preadipocytes may provide a new link between obesity and cardiovascular disease.


2013 ◽  
Vol 110 (10) ◽  
pp. 1803-1809 ◽  
Author(s):  
Renata de Azevedo Melo Luvizotto ◽  
Andre F. Nascimento ◽  
Erika Imaizumi ◽  
Damiana T. Pierine ◽  
Sandro J. Conde ◽  
...  

Obesity is characterised by chronic low-grade inflammation, and lycopene has been reported to display anti-inflammatory effects. However, it is not clear whether lycopene supplementation modulates adipokine levelsin vivoin obesity. To determine whether lycopene supplementation can regulate adipokine expression in obesity, male Wistar rats were randomly assigned to receive a control diet (C,n6) or a hyperenergetic diet (DIO,n12) for 6 weeks. After this period, the DIO animals were randomised into two groups: DIO (n6) and DIO supplemented with lycopene (DIO+L,n6). The animals received maize oil (C and DIO) or lycopene (DIO+L, 10 mg/kg body weight (BW) per d) by oral administration for a 6-week period. The animals were then killed by decapitation, and blood samples and epididymal adipose tissue were collected for hormonal determination and gene expression evaluation (IL-6, monocyte chemoattractant protein-1 (MCP-1),TNF-α, leptin and resistin). There was no detectable lycopene in the plasma of the C and DIO groups. However, the mean lycopene plasma concentration was 24 nmol in the DIO+L group. Although lycopene supplementation did not affect BW or adiposity, it significantly decreased leptin, resistin andIL-6gene expression in epididymal adipose tissue and plasma concentrations. Also, it significantly reduced the gene expression ofMCP-1in epididymal adipose tissue. Lycopene affects adipokines by reducing leptin, resistin and plasma IL-6 levels. These data suggest that lycopene may be an effective strategy in reducing inflammation in obesity.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Yuka Unno ◽  
Yoshinori Sato ◽  
Satoshi Nishida ◽  
Akiyo Nakano ◽  
Ryuichi Nakano ◽  
...  

Acinetobacter baumanniiis one of the most important nosocomial opportunistic pathogen worldwide. In addition, obesity has been associated with an increased risk of nosocomial infection, suggesting that there may be an association betweenA. baumanniiand white adipose tissue. However, the effects ofA. baumanniion adipocytes have not been well studied at the molecular level. Here, we investigated the potential role ofA. baumannii-derived lipopolysaccharides (LPS) as signaling molecules that affect adipocyte functionality. We tested the effect of increasing concentrations ofA. baumannii-derived LPS (10, 100, or 1000 ng/mL) on the 3T3-L1 adipocyte cell line. Exposure to LPS was found to increase the expression of several adipokines (e.g., MIP-2, MCP-1, TNF-α, IL-6, lipocalin-2, and FABP4) in 3T3-L1 adipocytes and significantly reduced the expression of leptin and adiponectin. The effects ofA. baumannii-derived LPS on MIP-2 expression were similar in comparison with that of LPS prepared fromPseudomonas aeruginosaandEscherichia coliin our cell culture-based system. This study suggests thatA. baumannii-derived LPS functions as a signaling molecule that impacts the inflammatory function of white adipose tissue on the level of gene expression.


2021 ◽  
Author(s):  
Dipanjan Chattopadhyay ◽  
Snehasis Das ◽  
Suktara Guria ◽  
Soumyadeep Basu ◽  
Sutapa Mukherjee

In the context of obesity-induced adipose tissue inflammation, migration of macrophages and their polarization from predominantly anti-inflammatory to proinflammatory subtype is considered a pivotal event in the loss of adipose insulin sensitivity. Two major chemoattractants, monocyte chemoattractant protein-1 (MCP-1) and Fetuin A (FetA), have been reported to stimulate macrophage migration into inflamed adipose tissue instigating inflammation. Moreover, FetA could notably modulate macrophage polarization, yet the mechanism(s) is unknown. The present study was undertaken to elucidate the mechanistic pathway involved in the actions of FetA and MCP-1 in obese adipose tissue. We found that FetA knockdown in high fat diet (HFD) fed mice could significantly subdue the augmented MCP-1 expression and reduce adipose tissue macrophage (ATM) content thereby indicating that MCP-1 is being regulated by FetA. Additionally, knockdown of FetA in HFD mice impeded the expression of inducible nitric oxide synthase (iNOS) reverting macrophage activation from mostly proinflammatory to anti-inflammatory state. It was observed that the stimulating effect of FetA on MCP-1 and iNOS was mediated through interferon γ (IFNγ) induced activation of JAK2-STAT1-NOX4 pathway. Furthermore, we detected that the enhanced IFNγ expression was accounted by the stimulatory effect of FetA upon the activities of both cJun and JNK. Taken together, our findings revealed that obesity-induced FetA acts as a master upstream regulator of adipose tissue inflammation by regulating MCP-1 and iNOS expression through JNK-cJun-IFNγ-JAK2-STAT1 signaling pathway. This study opened a new horizon in understanding the regulation of ATM content and activation in conditions of obesity-induced insulin resistance.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Josefin Henninger ◽  
Björn Eliasson ◽  
Ulf Smith ◽  
Aidin Rawshani

AbstractThe study of metabolomics has improved our knowledge of the biology behind type 2 diabetes and its related metabolic physiology. We aimed to investigate markers of adipose tissue morphology, as well as insulin and glucose metabolism in 53 non-obese male individuals. The participants underwent extensive clinical, biochemical and magnetic resonance imaging phenotyping, and we also investigated non-targeted serum metabolites. We used a multi-modal machine learning approach to evaluate which serum metabolomic compounds predicted markers of glucose and insulin metabolism, adipose tissue morphology and distribution. Fasting glucose was associated with metabolites of intracellular insulin action and beta-cell dysfunction, namely cysteine-s-sulphate and n-acetylgarginine, whereas fasting insulin was predicted by myristoleoylcarnitine, propionylcarnitine and other metabolites of beta-oxidation of fatty acids. OGTT-glucose levels at 30 min were predicted by 7-Hoca, a microbiota derived metabolite, as well as eugenol, a fatty acid. Both insulin clamp and HOMA-IR were predicted by metabolites involved in beta-oxidation of fatty acids and biodegradation of triacylglycerol, namely tartrate and 3-phosphoglycerate, as well as pyruvate, xanthine and liver fat. OGTT glucose area under curve (AUC) and OGTT insulin AUC, was associated with bile acid metabolites, subcutaneous adipocyte cell size, liver fat and fatty chain acids and derivates, such as isovalerylcarnitine. Finally, subcutaneous adipocyte size was associated with long chain fatty acids, markers of sphingolipid metabolism, increasing liver fat and dopamine-sulfate 1. Ectopic liver fat was predicted by methylmalonate, adipocyte cell size, glutathione derived metabolites and fatty chain acids. Ectopic heart fat was predicted visceral fat, gamma-glutamyl tyrosine and 2-acetamidophenol sulfate. Adipocyte cell size, age, alpha-tocopherol and blood pressure were associated with visceral fat. We identified several biomarkers associated with adipose tissue pathophysiology and insulin and glucose metabolism using a multi-modal machine learning approach. Our approach demonstrated the relative importance of serum metabolites and they outperformed traditional clinical and biochemical variables for most endpoints.


Angiology ◽  
2021 ◽  
pp. 000331972110125
Author(s):  
Vlatka Pandzic Jaksic ◽  
Danijela Grizelj ◽  
Ana Livun ◽  
Marko Ajduk ◽  
Drago Boscic ◽  
...  

The inflammatory phenotype of neck adipose tissue (NAT) might reflect its involvement in the pathogenesis of carotid atherosclerosis. We investigated inflammatory gene expression in the subcutaneous and the perivascular (pericarotid) adipose tissue from patients with carotid stenosis (CS) undergoing endarterectomy and a control group of patients without significant carotid atherosclerosis undergoing thyroid surgery. Only male patients were included (n = 13 in each study group). Clinical and biochemical data along with serum leptin, adiponectin, and monocyte chemoattractant protein 1 (MCP-1) were collected. Adipose tissue samples were obtained from both the subcutaneous and pericarotid compartments. Real-time polymerase chain reaction was used to measure gene expression of macrophage markers and adipokines. The CS group had higher subcutaneous and pericarotid visfatin gene expression and higher pericarotid expression of MCP-1 and CD68 genes. The ratio between pericarotid CD206 and CD68 gene expression was similar between study groups. Adiponectin gene expression in both NAT compartments did not differ between groups, but it was negatively associated with body weight. These observations suggest that NAT, and especially the pericarotid compartment, express enhanced inflammatory properties in patients with CS, but the proportion of anti-inflammatory macrophages in advanced atherosclerosis seems to be maintained.


2018 ◽  
Vol 16 ◽  
pp. 205873921879297 ◽  
Author(s):  
Xue Xu ◽  
Mei-Yu Qi ◽  
Shuang Liu ◽  
Xu-Ting Song ◽  
Jia-Nan Zhang ◽  
...  

Saturated fatty acids (SFAs) can directly stimulate innate immune responses, thereby exacerbating inflammatory aspects of metabolic syndrome. Dietary SFAs act as ligands of Toll-like receptor 4 (TLR4), triggering associated signaling pathways. In this study, we investigated the role of TLR4 in palm oil SFA-associated inflammatory cytokine gene expression in monocytes/macrophages and adipose tissue using TLR4-overexpressing genetically modified sheep. SFA stimulation resulted in upregulation of interleukin-6 ( IL-6), tumor necrosis factor-α ( TNF-α), interleukin-8 ( IL-8), interferon-γ ( IFN-γ), and interleukin-10 ( IL-10), and TLR4 overexpression enhanced such SFA-induced inflammatory cytokine expression. Moreover, SFAs markedly activated MyD88-dependent signaling, including IL-1 receptor–associated kinase 4 ( IRAK4), TNF receptor–associated factor 6 ( TRAF6), and nuclear factor-κB ( NF-κB). Taken together, our results indicate that TLR4 overexpression enhances the SFA-induced inflammatory response through MyD88-dependent signaling in monocytes/macrophages and adipose tissue.


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