scholarly journals Depot-Specific Modulation of Rat Intraabdominal Adipose Tissue Lipid Metabolism by Pharmacological Inhibition of 11β-Hydroxysteroid Dehydrogenase Type 1

Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 2391-2397 ◽  
Author(s):  
Magalie Berthiaume ◽  
Mathieu Laplante ◽  
William Festuccia ◽  
Yves Gélinas ◽  
Sébastien Poulin ◽  
...  

The metabolic consequences of visceral obesity have been associated with amplification of glucocorticoid action by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in adipose tissue. This study aimed to assess in a rat model of diet-induced obesity the effects of pharmacological 11β-HSD1 inhibition on the morphology and expression of key genes of lipid metabolism in intraabdominal adipose depots. Rats fed a high-sucrose, high-fat diet were treated or not with a specific 11β-HSD1 inhibitor (compound A, 3 mg/kg·d) for 3 wk. Compound A did not alter food intake or body weight gain but specifically reduced mesenteric adipose weight (−18%) and adipocyte size, without significantly affecting those of epididymal or retroperitoneal depots. In mesenteric fat, the inhibitor decreased (to 25–50% of control) mRNA levels of genes involved in lipid synthesis (FAS, SCD1, DGAT1) and fatty acid cycling (lipolysis/reesterification, ATGL and PEPCK) and increased (30%) the activity of the fatty acid oxidation-promoting enzyme carnitine palmitoyltransferase 1. In striking contrast, in the epididymal depot, 11β-HSD1 inhibition increased (1.5–5-fold) mRNA levels of those genes related to lipid synthesis/cycling and slightly decreased carnitine palmitoyltransferase 1 activity, whereas gene expression remained unaffected in the retroperitoneal depot. Compound A robustly reduced liver triacylglycerol content and plasma lipids. The study demonstrates that pharmacological inhibition of 11β-HSD1, at a dose that does not alter food intake, reduces fat accretion specifically in the mesenterical adipose depot, exerts divergent intraabdominal depot-specific effects on genes of lipid metabolism, and reduces steatosis and lipemia.

2008 ◽  
Vol 295 (6) ◽  
pp. E1369-E1379 ◽  
Author(s):  
Yongjie Ma ◽  
Leyuan Xu ◽  
Daniel Rodriguez-Agudo ◽  
Xiaobo Li ◽  
Douglas M. Heuman ◽  
...  

The oxysterol receptor LXR is a key transcriptional regulator of lipid metabolism. LXR increases expression of SREBP-1, which in turn regulates at least 32 genes involved in lipid synthesis and transport. We recently identified 25-hydroxycholesterol-3-sulfate (25HC3S) as an important regulatory molecule in the liver. We have now studied the effects of 25HC3S and its precursor, 25-hydroxycholesterol (25HC), on lipid metabolism as mediated by the LXR/SREBP-1 signaling in macrophages. Addition of 25HC3S to human THP-1-derived macrophages markedly decreased nuclear LXR protein levels. 25HC3S administration was followed by dose- and time-dependent decreases in SREBP-1 mature protein and mRNA levels. 25HC3S decreased the expression of SREBP-1-responsive genes, acetyl-CoA carboxylase-1, and fatty acid synthase (FAS) as well as HMGR and LDLR, which are key proteins involved in lipid metabolism. Subsequently, 25HC3S decreased intracellular lipids and increased cell proliferation. In contrast to 25HC3S, 25HC acted as an LXR ligand, increasing ABCA1, ABCG1, SREBP-1, and FAS mRNA levels. In the presence of 25HC3S, 25HC, and LXR agonist T0901317, stimulation of LXR targeting gene expression was repressed. We conclude that 25HC3S acts in macrophages as a cholesterol satiety signal, downregulating cholesterol and fatty acid synthetic pathways via inhibition of LXR/SREBP signaling. A possible role of oxysterol sulfation is proposed.


1959 ◽  
Vol 197 (1) ◽  
pp. 105-107 ◽  
Author(s):  
Guy Hollifield ◽  
William Parson

Compound A (11-dehydrocorticosterone) pellets implanted subcutaneously produced increased carcass fat and decreased protein in older mice but not in young mice of the DBA strain. The increased carcass fat is not the result of increased food intake or weight gain since it occurs in the face of a decreased food intake and weight loss and is associated with a decrease in spontaneous running activity. Adipose tissue of mice treated with compound A pellet implants has a greater lipid synthesis from C14-labeled acetate than that from cholesterol-treated controls. These findings lend support to the idea that compound A causes increased gluconeogenesis and increased insulin production with a resultant stimulation of fat synthesis by adipose tissue.


2003 ◽  
Vol 88 (8) ◽  
pp. 3983-3988 ◽  
Author(s):  
Deborah J. Wake ◽  
Eva Rask ◽  
Dawn E. W. Livingstone ◽  
Stefan Söderberg ◽  
Tommy Olsson ◽  
...  

In idiopathic obesity circulating cortisol levels are not elevated, but high intraadipose cortisol concentrations have been implicated. 11β-Hydroxysteroid dehydrogenase type 1 (11HSD1) catalyzes the conversion of inactive cortisone to active cortisol, thus amplifying glucocorticoid receptor (GR) activation. In cohorts of men and women, we have shown increased ex vivo 11HSD1 activity in sc adipose tissue associated with in vivo obesity and insulin resistance. Using these biopsies, we have now validated this observation by measuring 11HSD1 and GR mRNA and examined the impact on intraadipose cortisol concentrations, putative glucocorticoid regulated adipose target gene expression (angiotensinogen and leptin), and systemic measurements of cortisol metabolism. From aliquots of sc adipose biopsies from 16 men and 16 women we extracted RNA for real-time PCR and steroids for immunoassays. Adipose 11HSD1 mRNA was closely related to 11HSD1 activity [standardized β coefficient (SBC) = 0.58; P < 0.01], and both were positively correlated with parameters of obesity (e.g. for BMI, SBC = 0.48; P < 0.05 for activity, and SBC = 0.63; P < 0.01 for mRNA) and insulin sensitivity (log fasting plasma insulin; SBC = 0.44; P < 0.05 for activity, and SBC = 0.33; P = 0.09 for mRNA), but neither correlated with urinary cortisol/cortisone metabolite ratios. Adipose GR-α and angiotensinogen mRNA levels were not associated with obesity or insulin resistance, but leptin mRNA was positively related to 11HSD1 activity (SBC = 0.59; P < 0.05) and tended to be associated with parameters of obesity (BMI: SBC = 0.40; P = 0.09), fasting insulin (SBC = 0.65; P < 0.05), and 11HSD1 mRNA (SBC = 0.40; P = 0.15). Intraadipose cortisol (142 ± 30 nmol/kg) was not related to 11HSD1 activity or expression, but was positively correlated with plasma cortisol. These data confirm that idiopathic obesity is associated with transcriptional up-regulation of 11HSD1 in adipose, which is not detected by conventional in vivo measurements of urinary cortisol metabolites and is not accompanied by dysregulation of GR. Although this may drive a compensatory increase in leptin synthesis, whether it has an adverse effect on intraadipose cortisol concentrations and GR-dependent gene regulation remains to be established.


Parasitology ◽  
1987 ◽  
Vol 95 (1) ◽  
pp. 79-92 ◽  
Author(s):  
E. A. Rath ◽  
M. Walkey

SUMMARYInfection with Hymenolepis microstoma significantly affected the lipid metabolism of young male Balb/C mice. Infection increased the rates of hepatic fatty acid and cholesterol synthesis and cholesterol synthesis by the gut. Decreases were recorded in testicular fatty acid synthesis and in the weights of testes and white epididymal adipose tissue. Plasma glucose decreased rapidly during infection. The observed changes in lipogenesis could not be attributed to changes in food intake or body temperature. The changes are discussed in relation to nutritional interactions between host and parasite and the possible effects on host hormone levels. The presence of newly synthesized fatty acid in H. microstoma is also reported.


2014 ◽  
Vol 99 (1) ◽  
pp. E160-E168 ◽  
Author(s):  
Cristina L. Esteves ◽  
Val Kelly ◽  
Amandine Breton ◽  
Ashley I. Taylor ◽  
Christopher C. West ◽  
...  

Context: Levels of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which regenerates active glucocorticoids, are selectively elevated in adipose tissue in human obesity and metabolic syndrome, both conditions associated with chronic low-grade inflammation. 11β-HSD1 expression is induced by proinflammatory cytokines in a variety of cell types, including in human adipocytes differentiated in vitro. Objective: Our objective was to determine the mechanisms by which proinflammatory cytokines induce 11β-HSD1 in human adipocytes. Results: The proinflammatory cytokines IL-1α (10 ng/mL) and TNFα (20 ng/mL) increased 11β-HSD1 mRNA levels in human primary adipocyte fractions and Simpson-Golabi-Behmel syndrome (SGBS) adipocytes (P < .001). Inhibition of the MAPK/ERK kinase (MEK) attenuated CCAAT/enhancer binding protein (C/EBP) β phosphorylation at Thr235 and IL-1α/TNFα induction of 11β-HSD1 (P ≤ .007). The small interfering RNA-mediated knockdown of C/EBPβ and nuclear factor (NF)-κB/RelA or inhibition of NF-κB/RelA also attenuated cytokine induction of 11β-HSD1 (P ≤ .001). Moreover, induction of 11β-HSD1 by IL-1α in SGBS cells was associated with nuclear localization of C/EBPβ and NF-κB/RelA. Chromatin immunoprecipitation experiments showed C/EBPβ and NF-κB/RelA located to the 11β-HSD1 promoter in human adipose tissue. Treatment of adipocyte fractions or SGBS adipocytes with metformin or acetylsalicylic acid, which target C/EBPβ and NF-κB/RelA signaling, attenuated the IL-1α induction of 11β-HSD1 (P ≤ .002). Conclusions: Increased proinflammatory signaling in inflamed adipose tissue may mediate elevated 11β-HSD1 expression at this site via MEK, C/EBPβ, and NF-κB/RelA. These molecules/signaling pathways are, therefore, potential targets for drugs, including metformin and acetylsalicylic acid, to prevent/decreased up-regulation of 11β-HSD1 in human obese/metabolic syndrome adipose tissue.


2009 ◽  
Vol 161 (3) ◽  
pp. 375-380 ◽  
Author(s):  
Helga A Sigurjonsdottir ◽  
Ruth Andrew ◽  
Roland H Stimson ◽  
Gudmundur Johannsson ◽  
Brian R Walker

ObjectiveEvidence from long-term clinical studies measuring urinary steroid ratios, and from in vitro studies, suggests that GH administered for longer than 2 months down-regulates 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), thereby reducing cortisol regeneration in liver and adipose tissue. We aimed to measure acute effects of GH on 11β-HSD1 in liver and adipose tissue in vivo, including using a stable isotope tracer.DesignObservational studies of GH withdrawal and reintroduction in patients with hypopituitarism.MethodsTwelve men with benign pituitary disease causing GH and ACTH deficiency on stable replacement therapy for >6 months were studied after GH withdrawal for 3 weeks, and after either placebo or GH injections were reintroduced for another 3 weeks. We measured cortisol kinetics during 9,11,12,12-2H4-cortisol (d4-cortisol) infusion, urinary cortisol/cortisone metabolite ratios, liver 11β-HSD1 by appearance of plasma cortisol after oral cortisone, and 11β-HSD1 mRNA levels in subcutaneous adipose biopsies.ResultsGH withdrawal and reintroduction had no effect on 9,12,12-[2H]3-cortisol (d3-cortisol) appearance, urinary cortisol/cortisone metabolite ratios, initial appearance of cortisol after oral cortisone, or adipose 11β-HSD1 mRNA. GH withdrawal increased plasma cortisol 30–180 min after oral cortisone, increased d4-cortisol clearance, and decreased relative excretion of 5α-reduced cortisol metabolites.ConclusionsIn this setting, GH did not regulate 11β-HSD1 rapidly in vivo in humans. Altered cortisol metabolism with longer term changes in GH may reflect indirect effects on 11β-HSD1. These data do not suggest that glucocorticoid replacement doses need to be increased immediately after introducing GH therapy to compensate for reduced 11β-HSD1 activity, although dose adjustment may be required in the longer term.


2021 ◽  
Vol 22 (3) ◽  
pp. 1435
Author(s):  
Aimilia Papathanasiou ◽  
Fotios Spyropoulos ◽  
Zoe Michael ◽  
Kyoung Joung ◽  
Despina Briana ◽  
...  

Pulmonary hypertension (PH) is associated with meta-inflammation related to obesity but the role of adipose tissue in PH pathogenesis is unknown. We hypothesized that adipose tissue-derived metabolic regulators are altered in human and experimental PH. We measured circulating levels of fatty acid binding protein 4 (FABP-4), fibroblast growth factor -21 (FGF-21), adiponectin, and the mRNA levels of FABP-4, FGF-21, and peroxisome proliferator-activated receptor γ (PPARγ) in lung tissue of patients with idiopathic PH and healthy controls. We also evaluated lung and adipose tissue expression of these mediators in the three most commonly used experimental rodent models of pulmonary hypertension. Circulating levels of FABP-4, FGF-21, and adiponectin were significantly elevated in PH patients compared to controls and the mRNA levels of these regulators and PPARγ were also significantly increased in human PH lungs and in the lungs of rats with experimental PH compared to controls. These findings were coupled with increased levels of adipose tissue mRNA of genes related to glucose uptake, glycolysis, tricarboxylic acid cycle, and fatty acid oxidation in experimental PH. Our results support that metabolic alterations in human PH are recapitulated in rodent models of the disease and suggest that adipose tissue may contribute to PH pathogenesis.


1961 ◽  
Vol 200 (4) ◽  
pp. 847-850 ◽  
Author(s):  
Judith K. Patkin ◽  
E. J. Masoro

Cold acclimation is known to alter hepatic lipid metabolism. Liver slices from cold-acclimated rats have a greatly depressed capacity to synthesize long-chain fatty acids from acctate-1-C14. Since adipose tissue is the major site of lipogenic activity in the intact animal, its fatty acid synthetic capacity was studied. In contrast to the liver, it was found that adipose tissue from the cold-acclimated rat synthesized three to six times as much long-chain fatty acids per milligram of tissue protein as the adipose tissue from the control rat living at 25°C. Evidence is presented indicating that adipose tissue from cold-acclimated and control rats esterify long-chain fatty acids at the same rate. The ability of adipose tissue to oxidize palmitic acid to CO2 was found to be unaltered by cold acclimation. The fate of the large amount of fatty acid synthesized in the adipose tissue of cold-acclimated rats is discussed.


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