Regulation of adiponectin by adipose tissue-derived cytokines: in vivo and in vitro investigations in humans

2003 ◽  
Vol 285 (3) ◽  
pp. E527-E533 ◽  
Author(s):  
Jens M. Bruun ◽  
Aina S. Lihn ◽  
Camilla Verdich ◽  
Steen B. Pedersen ◽  
Søren Toubro ◽  
...  

Adiponectin is an adipose tissue-specific protein that is abundantly present in the circulation and suggested to be involved in insulin sensitivity and development of atherosclerosis. Because cytokines are suggested to regulate adiponectin, the aim of the present study was to investigate the interaction between adiponectin and three adipose tissue-derived cytokines (IL-6, IL-8, and TNF-α). The study was divided into three substudies as follows: 1) plasma adiponectin and mRNA levels in adipose tissue biopsies from obese subjects [mean body mass index (BMI): 39.7 kg/m2, n = 6] before and after weight loss; 2) plasma adiponectin in obese men (mean BMI: 38.7 kg/m2, n = 19) compared with lean men (mean BMI: 23.4 kg/m2, n = 10) before and after weight loss; and 3) in vitro direct effects of IL-6, IL-8, and TNF-α on adiponectin mRNA levels in adipose tissue cultures. The results were that 1) weight loss resulted in a 51% ( P < 0.05) increase in plasma adiponectin and a 45% ( P < 0.05) increase in adipose tissue mRNA levels; 2) plasma adiponectin was 53% ( P < 0.01) higher in lean compared with obese men, and plasma adiponectin was inversely correlated with adiposity, insulin sensitivity, and IL-6; and 3) TNF-α ( P < 0.01) and IL-6 plus its soluble receptor ( P < 0.05) decreased adiponectin mRNA levels in vitro. The inverse relationship between plasma adiponectin and cytokines in vivo and the cytokine-induced reduction in adiponectin mRNA in vitro suggests that endogenous cytokines may inhibit adiponectin. This could be of importance for the association between cytokines (e.g., IL-6) and insulin resistance and atherosclerosis.

2003 ◽  
Vol 285 (5) ◽  
pp. E1072-E1080 ◽  
Author(s):  
Aina S. Lihn ◽  
Bjørn Richelsen ◽  
Steen B. Pedersen ◽  
Steen B. Haugaard ◽  
Gulla Søby Rathje ◽  
...  

Human immunodeficiency virus (HIV)-associated lipodystrophy syndrome (HALS) is a side effect of highly active antiretroviral therapy of HIV-infected patients; however, the mechanism of the lipodystrophy and insulin resistance seen in this syndrome remains elusive. Adiponectin, an adipocyte-specific protein, is thought to play an important role in regulating insulin sensitivity. We investigated circulating levels and gene expression of adiponectin in subcutaneous abdominal adipose tissue (AT) from 18 HIV-infected patients with HALS compared with 18 HIV-infected patients without HALS. Implications of cytokines for adiponectin levels were investigated by determining circulating levels of TNF-α, IL-6, and IL-8 as well as gene expression of these cytokines in AT. HALS patients exhibited 40% reduced plasma adiponectin levels ( P < 0.05) compared with non-HALS subjects. Correspondingly, adiponectin mRNA levels in AT were reduced by >50% ( P = 0.06). HALS patients were insulin resistant, and a positive correlation was found between plasma adiponectin and insulin sensitivity ( r = 0.55, P < 0.01) and percent limb fat ( r = 0.61, P < 0.01). AT mRNA of TNF-α, IL-6, and IL-8 was increased in AT of HALS subjects ( P < 0.05), and both AT TNF-α mRNA and plasma TNF-α were negatively correlated to plasma adiponectin ( P < 0.05). Finally, TNF-α was found in vitro to inhibit human AT adiponectin mRNA by 80% ( P < 0.05). In conclusion, HALS patients have reduced levels of plasma adiponectin and adiponectin mRNA in AT. Increased cytokine mRNA in AT is hypothesized to exert an inhibitory effect on adiponectin gene expression and, consequently, to play a role in the reduced plasma adiponectin levels found in HALS patients.


2006 ◽  
Vol 291 (4) ◽  
pp. E843-E848 ◽  
Author(s):  
Lauren N. Bell ◽  
Jennifer L. Ward ◽  
Mikako Degawa-Yamauchi ◽  
Jason E. Bovenkerk ◽  
RoseMarie Jones ◽  
...  

Serum HGF is elevated in obese individuals. This study examined the contribution of excess adipose tissue to increased circulating HGF levels in obesity. Serum HGF was measured by ELISA before and after weight loss due to bariatric surgery or a 24-h fast. At 6.1 ± 0.1 mo following surgery, BMI (50.6 ± 1.6 vs. 35.1 ± 1.3 kg/m2; P < 0.0001) and serum HGF were significantly decreased (1,164 ± 116 vs. 529 ± 39 pg/ml, P < 0.001). A 24-h fast did not change serum HGF, but serum leptin was significantly reduced (67.7 ± 7.1 vs. 50.3 ± 8.3 ng/ml, P = 0.02). HGF secretion in vitro from adipocytes of obese (BMI 40.3 ± 2.8 kg/m2) subjects was significantly greater (80.9 ± 10.4 vs. 21.5 ± 4.0 pg/105 cells, P = 0.008) than release from adipocytes of lean (BMI 23.3 ± 1.4 kg/m2) subjects. HGF mRNA levels determined by real-time RT-PCR were not different in adipocytes from lean (BMI 24.0 ± 0.8 kg/m2) and obese (45.7 ± 3.0 kg/m2) subjects, but serum HGF was significantly elevated in the obese individuals studied (787 ± 61 vs. 489 ± 49 pg/ml, P = 0.001). TNF-α (24 h treatment) significantly increased HGF release from subcutaneous adipocytes 23.6 ± 8.3% over control ( P = 0.02). These data suggest that elevated serum HGF in obesity is in part attributable to excess adipose tissue and that this effect can be reversed by reducing adipose tissue mass through weight loss. Increased HGF secretion from adipocytes of obese subjects may be due to posttranscriptional events possibly related to adipocyte size and stimulation by elevated TNF-α in the adipose tissue of obese individuals.


2006 ◽  
Vol 155 (1) ◽  
pp. 161-165 ◽  
Author(s):  
M J Kim ◽  
M Maachi ◽  
C Debard ◽  
E Loizon ◽  
K Clément ◽  
...  

Objective: To investigate the mRNA expression of adiponectin, AdipoR1 and AdipoR2, the two recently cloned adiponectin receptors and peroxisome proliferator activated receptor (PPAR)γ2 in adipose tissue of obese individuals before and during a very low calorie diet (VLCD) inducing weight loss. Methods: Twenty-three non-diabetic obese subjects with normal (NGT, n=11) or impaired glucose tolerance (IGT, n=12) (age, 47±3 years; body mass index, 39.3±1.3 kg/m2) were studied before and after a 3-week 3.9 MJ diet daily without exercise. mRNA levels of nine IGT and six NGT subjects were measured by real-time PCR in s.c. abdominal adipose tissue. Results: Metabolic parameters and insulin sensitivity were improved by VLCD in the IGT group, but minimally affected in the NGT group. VLCD increased expression of AdipoR1 in the IGT (P=0.02), but not in the NGT group. Adiponectin, AdipoR2 and PPARγ2 mRNA levels did not change during VLCD in any group. In the IGT, but not in the NGT group, AdipoR1 and AdipoR2 expressions were positively related to that of PPARγ2 and, after VLCD, AdipoR1 and AdipoR2 expressions were positively related to each other and to that of adiponectin. Conclusion: In the NGT group, the 3-week VLCD inducing weight loss did not modify metabolic parameters, insulin sensitivity and the expression of the adiponectin system in adipose tissue. By contrast, in the IGT group, AdipoR1 expression increased and we found a coordinate regulation of the expression of adiponectin and its receptors. These modifications could participate, through adiponectin action on adipocytes, to the improved metabolic parameters observed in IGT subjects.


2008 ◽  
Vol 158 (6) ◽  
pp. 905-910 ◽  
Author(s):  
Isabelle Castan-Laurell ◽  
Michaela Vítkova ◽  
Danièle Daviaud ◽  
Cédric Dray ◽  
Michaela Kováčiková ◽  
...  

ObjectiveApelin is a novel adipokine acting on APJ receptor, regulated by insulin and tumor necrosis factor-α (TNF-α) in adipose tissue (AT). Plasma apelin levels are increased in obese hyperinsulinemic subjects. The aim was to investigate whether the hypocaloric diet associated with weight loss modifies the elevated plasma apelin levels and the expression of apelin and APJ receptor in AT in obese women.Design and methodsFasting plasma levels of apelin and TNF-α as well as mRNA levels of apelin and APJ in AT were measured before and after a 12-week hypocaloric weight-reducing diet in 20 obese women (body mass index (BMI) before diet 32.2±6.4 kg/m2). Twelve healthy women with a BMI of 20.7±0.6 kg/m2 served as reference.ResultsPlasma levels of apelin and TNF-α were higher in obese compared with lean controls. The hypocaloric diet resulted in a significant decrease of BMI to 29.8±6.3 kg/m2, plasma insulin (8.16±0.73 to 6.58±0.66 mU/l), apelin (369±25 pg/ml to 257±12 pg/ml), TNF-α levels (0.66±0.04 pg/ml to 0.56±0.04 pg/ml), and AT mRNAs of apelin and APJ. In addition, changes in AT mRNA apelin were related to changes in AT mRNA APJ levels.ConclusionThe hypocaloric diet associated with weight loss reduces the increased plasma and AT expression of apelin in obese women. This reduced apelin expression in AT could contribute to decreased circulating apelin levels.


2018 ◽  
Vol 315 (5) ◽  
pp. C653-C663 ◽  
Author(s):  
Kasin Yadunandam Anandam ◽  
Omar A. Alwan ◽  
Veedamali S. Subramanian ◽  
Padmanabhan Srinivasan ◽  
Rubina Kapadia ◽  
...  

Riboflavin (RF), is essential for normal cellular metabolism/function. Intestinal RF absorption occurs via a specific carrier-mediated process that involves the apical transporter RFVT-3 ( SLC52A3) and the basolateral RFVT-1 (SLC52A1). Previously, we characterized different cellular/molecular aspects of the intestinal RF uptake process, but nothing is known about the effect of proinflammatory cytokines on the uptake event. We addressed this issue using in vitro, ex vivo, and in vivo models. First, we determined the level of mRNA expression of the human (h)RFVT-3 and hRFVT-1 in intestinal tissue of patients with inflammatory bowel disease (IBD) and observed a markedly lower level compared with controls. In the in vitro model, exposing Caco-2 cells to tumor necrosis factor-α (TNF-α) led to a significant inhibition in RF uptake, an effect that was abrogated upon knocking down TNF receptor 1 (TNFR1). The inhibition in RF uptake was associated with a significant reduction in the expression of hRFVT-3 and -1 protein and mRNA levels, as well as in the activity of the SLC52A3 and SLC52A1 promoters. The latter effects appear to involve Sp1 and NF-κB sites in these promoters. Similarly, exposure of mouse small intestinal enteroids and wild-type mice to TNF-α led to a significant inhibition in physiological and molecular parameters of intestinal RF uptake. Collectively, these findings demonstrate that exposure of intestinal epithelial cells to TNF-α leads to inhibition in RF uptake and that this effect is mediated, at least in part, via transcriptional mechanism(s). These findings may explain the significantly low RF levels observed in patients with IBD.


Nutrients ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2032
Author(s):  
Vishnu Raj ◽  
Balaji Venkataraman ◽  
Saeeda Almarzooqi ◽  
Sanjana Chandran ◽  
Shreesh K. Ojha ◽  
...  

Nerolidol (NED) is a naturally occurring sesquiterpene alcohol present in various plants with potent anti-inflammatory effects. In the current study, we investigated NED as a putative anti-inflammatory compound in an experimental model of colonic inflammation. C57BL/6J male black mice (C57BL/6J) were administered 3% dextran sodium sulfate (DSS) in drinking water for 7 days to induce colitis. Six groups received either vehicle alone or DSS alone or DSS with oral NED (50, 100, and 150 mg/kg body weight/day by oral gavage) or DSS with sulfasalazine. Disease activity index (DAI), colonic histology, and biochemical parameters were measured. TNF-α-treated HT-29 cells were used as in vitro model of colonic inflammation to study NED (25 µM and 50 µM). NED significantly decreased the DAI and reduced the inflammation-associated changes in colon length as well as macroscopic and microscopic architecture of the colon. Changes in tissue Myeloperoxidase (MPO) concentrations, neutrophil and macrophage mRNA expression (CXCL2 and CCL2), and proinflammatory cytokine content (IL-1β, IL-6, and TNF-α) both at the protein and mRNA level were significantly reduced by NED. The increase in content of the proinflammatory enzymes, COX-2 and iNOS induced by DSS were also significantly inhibited by NED along with tissue nitrate levels. NED promoted Nrf2 nuclear translocation dose dependently. NED significantly increased antioxidant enzymes activity (Superoxide dismutase (SOD) and Catalase (CAT)), Hemeoxygenase-1 (HO-1), and SOD3 mRNA levels. NED treatment in TNF-α-challenged HT-29 cells significantly decreased proinflammatory chemokines (CXCL1, IL-8, CCL2) and COX-2 mRNA levels. NED supplementation attenuates colon inflammation through its potent antioxidant and anti-inflammatory activity both in in vivo and in vitro models of colonic inflammation.


Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3195
Author(s):  
Yo-Han Han ◽  
Jeong-Geon Mun ◽  
Hee Dong Jeon ◽  
Dae Hwan Yoon ◽  
Byung-Min Choi ◽  
...  

Background: Cachexia induced by cancer is a systemic wasting syndrome and it accompanies continuous body weight loss with the exhaustion of skeletal muscle and adipose tissue. Cancer cachexia is not only a problem in itself, but it also reduces the effectiveness of treatments and deteriorates quality of life. However, effective treatments have not been found yet. Although Arctii Fructus (AF) has been studied about several pharmacological effects, there were no reports on its use in cancer cachexia. Methods: To induce cancer cachexia in mice, we inoculated CT-26 cells to BALB/c mice through subcutaneous injection and intraperitoneal injection. To mimic cancer cachexia in vitro, we used conditioned media (CM), which was CT-26 colon cancer cells cultured medium. Results: In in vivo experiments, AF suppressed expression of interleukin (IL)-6 and atrophy of skeletal muscle and adipose tissue. As a result, the administration of AF decreased mortality by preventing weight loss. In adipose tissue, AF decreased expression of uncoupling protein 1 (UCP1) by restoring AMP-activated protein kinase (AMPK) activation. In in vitro model, CM increased muscle degradation factors and decreased adipocytes differentiation factors. However, these tendencies were ameliorated by AF treatment in C2C12 myoblasts and 3T3-L1 cells. Conclusion: Taken together, our study demonstrated that AF could be a therapeutic supplement for patients suffering from cancer cachexia.


2003 ◽  
Vol 284 (2) ◽  
pp. E443-E448 ◽  
Author(s):  
A. S. Lihn ◽  
T. Østergård ◽  
B. Nyholm ◽  
S. B. Pedersen ◽  
B. Richelsen ◽  
...  

Adiponectin is suggested to be an important mediator of insulin resistance. Therefore, we investigated the association between adiponectin and insulin sensitivity in 22 healthy first-degree relatives (FDR) to type 2 diabetic patients and 13 matched control subjects. Subcutaneous adipose tissue biopsies were taken before and after a hyperinsulinemic euglycemic clamp. FDR subjects were insulin resistant, as indicated by a reduced Mvalue (4.44 vs. 6.09 mg · kg−1· min−1, P < 0.05). Adiponectin mRNA expression was 45% lower in adipose tissue from FDR compared with controls ( P < 0.01), whereas serum adiponectin was similar in the two groups (6.4 vs. 6.6 μg/ml, not significant). Insulin infusion reduced circulating levels of adiponectin moderately (11–13%) but significantly in both groups ( P < 0.05). In the control group, adiponectin mRNA levels were negatively correlated with fasting insulin ( P < 0.05) and positively correlated with insulin sensitivity ( P < 0.05). In contrast, these associations were not found in the FDR group. In conclusion, FDR have reduced adiponectin mRNA in subcutaneous adipose tissue but normal levels of circulating adiponectin. Adiponectin mRNA levels are positively correlated with insulin sensitivity in control subjects but not in FDR. These findings indicate dysregulation of adiponectin gene expression in FDR.


Biochimie ◽  
2005 ◽  
Vol 87 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Claire Lagathu ◽  
Minji Kim ◽  
Mustapha Maachi ◽  
Corinne Vigouroux ◽  
Pascale Cervera ◽  
...  

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