ICAM-1 expression in adipose tissue: effects of diet-induced obesity in mice

2006 ◽  
Vol 291 (6) ◽  
pp. C1232-C1239 ◽  
Author(s):  
Danett K. Brake ◽  
E. O'Brian Smith ◽  
Harry Mersmann ◽  
C. Wayne Smith ◽  
Rebecca L. Robker

Obesity has been linked to cardiovascular disease, hypertension, diabetes and the metabolic syndrome, with elevated markers of systemic inflammation. Intercellular adhesion molecule-1 (ICAM-1) is a transmembrane adhesion molecule involved in leukocyte migration to sites of inflammation. In human obesity, elevated expression of the soluble form of ICAM-1 (sICAM-1) is positively correlated with abdominal fat deposition. Increases in adiposity have also been correlated with macrophage infiltration into adipose tissue. Here we investigate adipose tissue production and transcriptional regulation of ICAM-1 in a mouse model of dietary obesity. After feeding mice a high-fat diet, ICAM-1 expression in serum and adipose tissue was analyzed by ELISA, Northern blotting, real-time quantitative PCR, and flow cytometry. After 6 mo on the high-fat diet, sICAM-1 levels significantly correlated with body weight and abdominal fat mass. ICAM-1 mRNA was expressed in adipose tissue of mice, with significantly higher levels in males than females. After only 3 wk, there were adipose tissue-specific increases in mRNAs for ICAM-1, IL-6, and monocyte chemoattractant protein-1 (MCP-1) in male mice. Analysis of the stromal-vascular fraction of male adipose tissue revealed CD11b-negative cells with increased surface ICAM-1 and CD34. We also found two populations of F4/80+, CD11b+, ICAM-1+ cells, one of which also expressed CD14 and CD11c and was increased in response to a high-fat diet. These results indicate that within 3 wk on a high-fat diet, male mice exhibited significant increases in pro-inflammatory factors and immune cell infiltration in adipose tissue that may represent links between obesity and its associated inflammatory complications.

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yingfu Chen ◽  
Burong Feng ◽  
Ye Yuan ◽  
Juan Hu ◽  
Wei Zhao ◽  
...  

Background. Aloe emodin (AE) is a lipid-lowering agent, which could be used to treat hyperlipidemia, thereby reducing the risk of cardiovascular disease. Recent evidence suggests that hyperlipidemia is associated with many cardiac pathological alterations and might worsen myocardial damages. Purpose. The purpose of this study is to evaluate the potential roles and mechanisms of AE in hyperlipidemia-induced oxidative stress and inflammation in the heart. Study Design. We established a hyperlipidemia-induced cardiac inflammation model in rats and cells then administered AE and observed its effect on hyperlipidemia-induced cardiac inflammation. Methods. We used a mouse model of hyperlipidemia caused by a high-fat diet (HFD) for 10 weeks and cell culture experimental models of inflammation in the heart stimulated by PA for 14 h. Inflammatory markers were detected by qRT-PCR, WB, and immunofluorescence. Results. We demonstrated that the expression levels of proinflammatory cytokines IL-1β, IL-6, and TNF-α were increased in the HFD group compared to the normal diet (ND) group, whereas AE treatment significantly reduced their levels in the myocardium. In addition, vascular cell adhesion molecule 1 (VCAM1) and intercellular adhesion molecule 1 (ICAM-1) protein expressions were also inhibited by AE. Our in vitro study showed AE treatment dose-dependently decreased the expression of IL-1β, IL-6, and TNF-α in PA-treated H9C2 cells. Further experiments revealed that AE inhibited PA-induced cell death and promoted the production of intracellular reactive oxygen species (ROS). Mechanically, AE significantly suppressed the upregulation in protein levels of TLR4, IκB, and p-P65l in vivo and in vitro. Conclusion. Taken together, our findings disclose that AE could alleviate HFD/PA-induced cardiac inflammation via inhibition of the TLR4/NF-κB signaling pathway. Thus, AE may be a promising therapeutic strategy for preventing hyperlipidemia-induced myocardial injury.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jianfei Lai ◽  
Qianyu Qian ◽  
Qinchao Ding ◽  
Li Zhou ◽  
Ai Fu ◽  
...  

Background: Salvianolic acid A (Sal A), a natural polyphenolic compound extracted from Radix Salvia miltiorrhiza (Danshen), exhibits exceptional pharmacological activities against cardiovascular diseases. While a few studies have reported anti-obesity properties of Sal A, the underlying mechanisms are largely unknown. Given the prevalence of obesity and promising potential of browning of white adipose tissue to combat obesity, recent research has focused on herbal ingredients that may promote browning and increase energy expenditure.Purpose: The present study was designed to investigate the protective antiobesity mechanisms of Sal A, in part through white adipose browning.Methods: Both high-fat diet (HFD)-induced obese (DIO) male mice model and fully differentiated C3H10T1/2 adipocytes from mouse embryo fibroblasts were employed in this study. Sal A (20 and 40 mg/kg) was administrated to DIO mice by intraperitoneal injection for 13-weeks. Molecular mechanisms mediating effects of Sal A were evaluated.Resluts: Sal A treatment significantly attenuated HFD-induced weight gain and lipid accumulation in epididymal fat pad. Uncoupling protein 1 (UCP-1), a specialized thermogenic protein and marker for white adipocyte browning, was significantly induced by Sal A treatment in both white adipose tissues and cultured adipocytes. Further mechanistic investigations revealed that Sal A robustly reversed HFD-decreased AMP-activated protein kinase (AMPK) phosphorylation and sirtuin 1 (SIRT1) expression in mice. Genetically silencing either AMPK or SIRT1 using siRNA abolished UCP-1 upregulation by Sal A. AMPK silencing significantly blocked Sal A-increased SIRT1 expression, while SIRT1 silencing did not affect Sal A-upregulated phosphorylated-AMPK. These findings indicate that AMPK was involved in Sal A-increased SIRT1.Conclusion: Sal A increases white adipose tissue browning in HFD-fed male mice and in cultured adipocytes. Thus, Sal is a potential natural therapeutic compound for treating and/or preventing obesity.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2421-2421
Author(s):  
Constance Tom Noguchi ◽  
Heather Marie Rogers

Erythropoietin (EPO) promotes erythroid differentiation and increases glucose uptake in erythroid progenitor cells in culture. The metabolic burden associated with EPO treatment in adult mice is suggested by a decrease in body weight concomitant with increased hematocrit. Wild type male mice (C57Bl/6, age 8 months) treated with EPO showed the expected increase in hematocrit accompanied by a fall in blood glucose level and a decrease in body weight and fat mass. However, the decrease in body weight is even more evident in obese mice on a high fat diet and has also been linked to non-hematopoietic response, particularly with EPO receptor (EpoR) expression in white adipose tissue. We examined the metabolic burden of EPO treatment (3000U/kg for 3 weeks) in young, lean male mice (3 months) placed on high fat diet at the time of EPO administration. The increase in hematocrit was accompanied by decreased blood glucose level and improved glucose tolerance. However, no difference in body weight was observed between mice treated with EPO and the saline treated group, suggesting that the EPO stimulated decrease in body weight is evident primarily in older animals with greater fat mass. To determine the contribution of EpoR expression in non-hematopoietic tissue to the metabolic EPO response, young male mice with EpoR restricted to erythroid tissue (TgEpoR) were placed on high fat diet and treated with EPO. The expected increased hematocrit was also accompanied by decreased blood glucose level and improved glucose tolerance, and no change in body weight between EPO and saline treatment. The similar responses observed in young wild type and TgEpoR mice suggest that the EPO stimulated increase in glucose metabolism is associated with increased erythropoiesis rather than a direct EPO response in non-hematopoietic tissue. TgEpoR mice exhibit an age dependent increase in fat mass even greater than that observed in wild type mice, and by 8 months TgEpoR mice are obese, glucose intolerant and insulin resistant compared with wild type mice. At 8 months, TgEpoR mice treated with EPO show the increase in hematocrit and, despite the increase in fat mass, there is only a minimal decrease in body weight compared with wild type mice. These data provide evidence that in addition to the age dependent association of EPO stimulated decrease in body weight and fat mass, this decrease in body weight is due largely to EPO response related to EpoR expression in non-hematopoietic tissue. Interestingly, young male mice with targeted deletion of EpoR in adipose tissue placed on a high fat diet and treated with EPO show the increase in hematocrit and improvement in glucose tolerance, and at 8 months, the increase in hematocrit with EPO treatment is accompanied by minimal change in body weight. The similar metabolic response of these mice with targeted deletion of EpoR in adipose tissue to TgEpoR mice indicate the contribution of EpoR expression in adipose tissue to the loss of body weight and fat mass. Therefore, the metabolic burden associated with EPO stimulated erythropoiesis appears to be reflected in improved glucose metabolism and glucose tolerance with minimal or no effect on body weight, is evident in young, lean mice, and is independent of EpoR expression in non-hematopoietic tissue. In older mice, non-hematopoietic metabolic EPO response is more readily apparent as reflected in loss of body weight/fat mass, which overshadows the erythropoietic metabolic response. In combination, the metabolic response to EPO treatment results from EPO stimulated increased erythropoiesis, improved glucose metabolism and glucose tolerance, and an age dependent decrease in body weight and fat mass associated with EpoR expression in non-hematopoietic tissue, particularly in white adipose tissue. Disclosures No relevant conflicts of interest to declare.


Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 754
Author(s):  
Roberta Dourado Cavalcante da Cunha de Sá ◽  
Jussara de Jesus Simão ◽  
Viviane Simões da Silva ◽  
Talita Mendes de Farias ◽  
Maysa Mariana Cruz ◽  
...  

This study aimed to investigate the effects of two commercially available fish oils (FOs) containing different proportions of two omega-3 fatty acids (FA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the metabolic and endocrine dysfunctions of white adipose tissue resulting from obesity. Male C57BL/6J mice, 8 weeks old, received a control or high-fat diet (CO and HF groups, with 9% and 59% energy from fat, respectively) for 8 weeks. The next 8 weeks, the HF group was subdivided into HF, HF+FO/E (HF+5:1 EPA:DHA), and HF+FO/D (HF+5:1 DHA:EPA). Supplementation was performed by gavage, three times a week. All groups that received the HF diet had lower food and caloric intake, but a higher fat intake, body weight (BW) gain, glucose intolerance, and a significant increase in inguinal (ING), retroperitoneal (RP), and epididymal (EPI) adipose tissues when compared to the CO group. Additionally, HF and HF+FO/D groups showed insulin resistance, adipocyte hypertrophy, increased lipolysis and secretion of TNF-α, resistin and IL-10 adipokines by ING and RP adipocytes, and adiponectin only by the HF+FO/D group in ING adipocytes. All of these effects were completely reversed in the HF+FO/E group, which also showed partial reversion in BW gain and glucose intolerance. Both the HF+FO/E and HF+FO/D groups showed a reduction in ING and RP adipose depots when compared to the HF group, but only HF+FO/E in the EPI depot. HF+FO/E, but not HF+FO/D, was able to prevent the changes triggered by obesity in TNF-α, Il-10, and resistin secretion in ING and RP depots. These results strongly suggest that different EPA:DHA ratios have different impacts on the adipose tissue metabolism, FO being rich in EPA, but not in DHA, and effective in reversing the changes induced by obesity.


2011 ◽  
Vol 301 (5) ◽  
pp. E901-E911 ◽  
Author(s):  
Wentong Pan ◽  
Ester Ciociola ◽  
Manish Saraf ◽  
Batbayar Tumurbaatar ◽  
Demidmaa Tuvdendorj ◽  
...  

Ectonucleotide pyrophosphate phosphodiesterase (ENPP1) has been shown to negatively modulate insulin receptor and to induce cellular insulin resistance when overexpressed in various cell types. Systemic insulin resistance has also been observed when ENPP1 is overexpressed in multiple tissues of transgenic models and attributed largely to tissue insulin resistance induced in skeletal muscle and liver. Another key tissue in regulating glucose and lipid metabolism is adipose tissue (AT). Interestingly, obese patients with insulin resistance have been reported to have increased AT ENPP1 expression. However, the specific effects of ENPP1 in AT have not been studied. To better understand the specific role of AT ENPP1 on systemic metabolism, we have created a transgenic mouse model (C57/Bl6 background) with targeted overexpression of human ENPP1 in adipocytes, using aP2 promoter in the transgene construct ( AdiposeENPP1-TG). Using either regular chow or pair-feeding protocol with 60% fat diet, we compared body fat content and distribution and insulin signaling in adipose, muscle, and liver tissues of AdiposeENPP1-TG and wild-type (WT) siblings. We also compared response to intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT). Our results show no changes in Adipose ENPP1-TG mice fed a regular chow diet. After high-fat diet with pair-feeding protocol, AdiposeENPP1-TG and WT mice had similar weights. However, AdiposeENPP1-TG mice developed fatty liver in association with changes in AT characterized by smaller adipocyte size and decreased phosphorylation of insulin receptor Tyr1361 and Akt Ser473. These changes in AT function and fat distribution were associated with systemic abnormalities of lipid and glucose metabolism, including increased plasma concentrations of fatty acid, triglyceride, plasma glucose, and insulin during IPGTT and decreased glucose suppression during ITT. Thus, our results show that, in the presence of a high-fat diet, ENPP1 overexpression in adipocytes induces fatty liver, hyperlipidemia, and dysglycemia, thus recapitulating key manifestations of the metabolic syndrome.


2021 ◽  
Author(s):  
Ao Sun ◽  
Xiaoqin Hu ◽  
Huijian Chen ◽  
Yulan Ma ◽  
Xiyue Yan ◽  
...  

Ursolic acid increases the secretion of irisin by the PRDM16–PGC-1α–FNDC5 signal pathway to induce beiging of WAT and improve obese conditions.


Theranostics ◽  
2020 ◽  
Vol 10 (18) ◽  
pp. 8197-8210 ◽  
Author(s):  
Xueying Zhou ◽  
Zhelong Li ◽  
Meihao Qi ◽  
Ping Zhao ◽  
Yunyou Duan ◽  
...  

2020 ◽  
Vol 31 ◽  
pp. 1-13 ◽  
Author(s):  
Almudena Gomez-Hernandez ◽  
Andrea R. Lopez-Pastor ◽  
Carlota Rubio-Longas ◽  
Patrik Majewski ◽  
Nuria Beneit ◽  
...  

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