scholarly journals Peroxisome Proliferator-Activated Receptors-α and -γ, and cAMP-Mediated Pathways, Control Retinol-Binding Protein-4 Gene Expression in Brown Adipose Tissue

Endocrinology ◽  
2012 ◽  
Vol 153 (3) ◽  
pp. 1162-1173 ◽  
Author(s):  
Meritxell Rosell ◽  
Elayne Hondares ◽  
Sadahiko Iwamoto ◽  
Frank J. Gonzalez ◽  
Martin Wabitsch ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Retinol Binding Protein ◽  
Peroxisome Proliferator ◽  
Brown Adipocytes ◽  
Retinol Binding Protein 4 ◽  
White Adipocytes ◽  
Brown Adipose ◽  
Rbp4 Gene

Retinol binding protein-4 (RBP4) is a serum protein involved in the transport of vitamin A. It is known to be produced by the liver and white adipose tissue. RBP4 release by white fat has been proposed to induce insulin resistance. We analyzed the regulation and production of RBP4 in brown adipose tissue. RBP4 gene expression is induced in brown fat from mice exposed to cold or treated with peroxisome proliferator-activated receptor (PPAR) agonists. In brown adipocytes in culture, norepinephrine, cAMP, and activators of PPARγ and PPARα induced RBP4 gene expression and RBP4 protein release. The induction of RBP4 gene expression by norepinephrine required intact PPAR-dependent pathways, as evidenced by impaired response of the RBP4 gene expression to norepinephrine in PPARα-null brown adipocytes or in the presence of inhibitors of PPARγ and PPARα. PPARγ and norepinephrine can also induce the RBP4 gene in white adipocytes, and overexpression of PPARα confers regulation by this PPAR subtype to white adipocytes. The RBP4 gene promoter transcription is activated by cAMP, PPARα, and PPARγ. This is mediated by a PPAR-responsive element capable of binding PPARα and PPARγ and required also for activation by cAMP. The induction of the RBP4 gene expression by norepinephrine in brown adipocytes is protein synthesis dependent and requires PPARγ-coactivator-1-α, which acts as a norepinephine-induced coactivator of PPAR on the RBP4 gene. We conclude that PPARγ- and PPARα-mediated signaling controls RBP4 gene expression and releases in brown adipose tissue, and thermogenic activation induces RBP4 gene expression in brown fat through mechanisms involving PPARγ-coactivator-1-α coactivation of PPAR signaling.

scholarly journals Adrenergic stimulation of lipoprotein lipase gene expression in rat brown adipocytes differentiated in culture: mediation via β3- and α1-adrenergic receptors

1997 ◽  
Vol 321 (3) ◽  
pp. 759-767 ◽  
Author(s):  
Pertti KUUSELA ◽  
Stefan REHNMARK ◽  
Anders JACOBSSON ◽  
Barbara CANNON ◽  
Jan NEDERGAARD
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Lipoprotein Lipase ◽  
Direct Effect ◽  
Mrna Levels ◽  
Adrenergic Stimulation ◽  
Brown Adipocytes ◽  
Brown Adipose ◽  
Lpl Gene

In order to investigate whether the positive effect of adrenergic stimulation on lipoprotein lipase (LPL) gene expression in brown adipose tissue is a direct effect on the brown adipocytes themselves, the expression of the LPL gene was investigated by measuring LPL mRNA levels in brown adipocytes, isolated as precursors from the brown adipose tissue of rats and grown in culture in a fully defined medium before experimentation. Addition of noradrenaline led to an enhancement of LPL gene expression; the mRNA levels increased as a linear function of time for at least 5 h and were finally approx. 3 times higher than in control cells, an increase commensurate with that seen in vivoin both LPL mRNA levels and LPL activity during physiological stimulation. The increase was dependent on transcription. The effect of noradrenaline showed simple MichaelisŐMenten kinetics with an EC50 of approx. 11 nM. β3-Agonists (BRL-37344 and CGP-12177) could mimic the effect of noradrenaline; the β1-agonist dobutamine and the β2-agonist salbutamol could not; the α1-agonist cirazoline had only a weak effect. The effect of noradrenaline was fully inhibited by the β-antagonist propranolol and was halved by the α1-antagonist prazosin; the α2-antagonist yohimbine was without effect. An increase in LPL mRNA level similar to (but not significantly exceeding) that caused by noradrenaline could also be induced by the cAMP-elevating agents forskolin and cholera toxin, and 8-Br-cAMP also increased LPL mRNA levels. The increase in LPL gene expression was not mediated via an increase in the level of an intermediary proteinaceous factor. It is concluded that the physiologically induced increase in LPL gene expression is a direct effect of noradrenaline on the brown adipocytes themselves, mediated via a dominant β3-adrenergic pathway and an auxillary α1-adrenergic pathway which converge at a regulatory point in transcriptional control.

scholarly journals Comprehensive Messenger Ribonucleic Acid Profiling Reveals That Peroxisome Proliferator-Activated Receptor γ Activation Has Coordinate Effects on Gene Expression in Multiple Insulin-Sensitive Tissues

Endocrinology ◽  
2001 ◽  
Vol 142 (3) ◽  
pp. 1269-1277 ◽  
Author(s):  
James M. Way ◽  
W. Wallace Harrington ◽  
Kathleen K. Brown ◽  
William K. Gottschalk ◽  
Scott S. Sundseth ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Brown Adipose Tissue ◽  
White Adipose Tissue ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Expression Of Genes ◽  
Brown Adipose ◽  
Pparγ Agonists

Abstract Peroxisome proliferator-activated receptor γ (PPARγ) agonists, including the glitazone class of drugs, are insulin sensitizers that reduce glucose and lipid levels in patients with type 2 diabetes mellitus. To more fully understand the molecular mechanisms underlying their therapeutic actions, we have characterized the effects of the potent, tyrosine-based PPARγ ligand GW1929 on serum glucose and lipid parameters and gene expression in Zucker diabetic fatty rats. In time-course studies, GW1929 treatment decreased circulating FFA levels before reducing glucose and triglyceride levels. We used a comprehensive and unbiased messenger RNA profiling technique to identify genes regulated either directly or indirectly by PPARγ in epididymal white adipose tissue, interscapular brown adipose tissue, liver, and soleus skeletal muscle. PPARγ activation stimulated the expression of a large number of genes involved in lipogenesis and fatty acid metabolism in both white adipose tissue and brown adipose tissue. In muscle, PPARγ agonist treatment decreased the expression of pyruvate dehydrogenase kinase 4, which represses oxidative glucose metabolism, and also decreased the expression of genes involved in fatty acid transport and oxidation. These changes suggest a molecular basis for PPARγ-mediated increases in glucose utilization in muscle. In liver, PPARγ activation coordinately decreased the expression of genes involved in gluconeogenesis. We conclude from these studies that the antidiabetic actions of PPARγ agonists are probably the consequence of 1) their effects on FFA levels, and 2), their coordinate effects on gene expression in multiple insulin-sensitive tissues.

scholarly journals Effects of glucocorticoids on human brown adipocytes

2014 ◽  
Vol 224 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Johanna L Barclay ◽  
Hadiya Agada ◽  
Christina Jang ◽  
Micheal Ward ◽  
Neil Wetzig ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Negative Energy ◽  
Dependent Manner ◽  
Adrenergic Stimulation ◽  
Concentration Dependent Manner ◽  
Brown Adipocytes ◽  
White Adipocytes ◽  
Brown Adipose ◽  
And Function

Clinical cases of glucocorticoid (GC) excess are characterized by increased fat mass and obesity through the accumulation of white adipocytes. The effects of GCs on growth and function of brown adipose tissue are unknown and may contribute to the negative energy balance observed clinically. This study aims to evaluate the effect of GCs on proliferation, differentiation, and metabolic function of brown adipocytes. Human brown adipocytes sourced from supraclavicular fat biopsies were grown in culture and differentiated to mature adipocytes. Human white adipocytes sourced from subcutaneous abdominal fat biopsies were cultured as controls. Effects of dexamethasone on growth, differentiation (UCP1,CIDEA, andPPARGC1Aexpression), and function (oxygen consumption rate (OCR)) of brown adipocytes were quantified. Dexamethasone (1 μM) significantly stimulated the proliferation of brown preadipocytes and reduced that of white preadipocytes. During differentiation, dexamethasone (at 0.1, 1, and 10 μM) stimulated the expression ofUCP1,CIDEA, andPPARGC1Ain a concentration-dependent manner and enhanced by fourfold to sixfold the OCR of brown adipocytes. Isoprenaline (100 nM) significantly increased (P<0.05) expression ofUCP1and OCR of brown adipocytes. These effects were significantly reduced (P<0.05) by dexamethasone. Thus, we show that dexamethasone stimulates the proliferation, differentiation, and function of human brown adipocytes but inhibits adrenergic stimulation of the functioning of brown adipocytes. We conclude that GCs exert complex effects on development and function of brown adipocytes. These findings provide strong evidence for an effect of GCs on the biology of human brown adipose tissue (BAT) and for the involvement of the BAT system in the metabolic manifestation of Cushing's syndrome.

scholarly journals Identification of biomarkers of brown adipose tissue aging highlights the role of dysfunctional energy and nucleotide metabolism pathways

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Carola Mancini ◽  
Sabrina Gohlke ◽  
Francisco Garcia-Carrizo ◽  
Vyacheslav Zagoriy ◽  
Heike Stephanowitz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Nucleotide Metabolism ◽  
Brown Adipocyte ◽  
Brown Adipocytes ◽  
Interscapular Brown Adipose Tissue ◽  
Potential Biomarker ◽  
Brown Adipose ◽  
Tissue Aging

AbstractBrown adipose tissue function declines during aging and may contribute to the onset of metabolic disorders such as diabetes and obesity. Only limited understanding of the mechanisms leading to the metabolic impairment of brown adipocytes during aging exists. To this end, interscapular brown adipose tissue samples were collected from young and aged mice for quantification of differential gene expression and metabolite levels. To identify potential processes involved in brown adipocyte dysfunction, metabolite concentrations were correlated to aging and significantly changed candidates were subsequently integrated with a non-targeted proteomic dataset and gene expression analyses. Our results include novel age-dependent correlations of polar intermediates in brown adipose tissue. Identified metabolites clustered around three biochemical processes, specifically energy metabolism, nucleotide metabolism and vitamin metabolism. One mechanism of brown adipose tissue dysfunction may be linked to mast cell activity, and we identify increased histamine levels in aged brown fat as a potential biomarker. In addition, alterations of genes involved in synthesis and degradation of many metabolites were mainly observed in the mature brown adipocyte fraction as opposed to the stromal vascular fraction. These findings may provide novel insights on the molecular mechanisms contributing to the impaired thermogenesis of brown adipocytes during aging.

scholarly journals Regulation of gene expression by FSP27 in white and brown adipose tissue

BMC Genomics ◽  
2010 ◽  
Vol 11 (1) ◽  
pp. 446 ◽  
Author(s):  
De Li ◽  
Yinxin Zhang ◽  
Li Xu ◽  
Linkang Zhou ◽  
Yue Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Regulation Of Gene Expression ◽  
Brown Adipose

scholarly journals Brown adipose tissue activity is modulated in olanzapine-treated young rats by simvastatin

2020 ◽  
Author(s):  
Xuemei Liu ◽  
Xiyu Feng ◽  
Chao Deng ◽  
Lu Liu ◽  
Yanping Zeng ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Weight Gain ◽  
Food Intake ◽  
Brown Adipose Tissue ◽  
Body Weight Gain ◽  
Uncoupling Protein ◽  
Peroxisome Proliferator ◽  
Sprague Dawley ◽  
Olanzapine Treatment ◽  
Brown Adipose

Abstract BackgroundPrescription of second-generation antipsychotic drugs (SGAs) to childhood/adolescent has exponentially increased in recent years, which was associated with the greater risk of significant sedation, weight gain, and dyslipidemia. Statin is considered a potential preventive and treatment approach for reducing SGA-induced weight gain and dyslipidemia in schizophrenia patients. However, the effect of statin treatment in children and adolescents with SGA-induced dyslipidemia is not clearly demonstrated.MethodsTo investigate the efficacy of interventions of statin aimed at reversing SGA-induced dyslipidemia, young Sprague Dawley (SD) rats were treated orally with either olanzapine (1.0 mg/kg, t.i.d.), simvastatin (3.0 mg/kg, t.i.d.), olanzapine plus simvastatin (O+S), or vehicle (control) for 5 weeks.ResultsOlanzapine treatment increased weight gain, food intake and feeding efficiency compared to the control, while O+S co-treatment significantly reversed body weight gain but had no significant effect on food intake. Moreover, olanzapine treatment induced a slight but significant reduction in body temperature, with a decrease in locomotor activity. Fasting plasma glucose, triglycerides (TG), and total cholesterol (TC) levels were markedly elevated in the olanzapine-only group, whereas O+S co-treatment significantly ameliorated these changes. A down-regulating of uncoupling protein-1 (UCP1) and peroxisome-proliferator-activated receptor-γ co-activator-1α (PGC-1α) expression was observed in brown adipose tissue (BAT) in the olanzapine-only group, following a significant decrease in the ratio of phosphorylated PKA (p-PKA)/PKA. Interestingly, these protein changes could be reversed by co-treatment with O+B. Our results demonstrated simvastatin to be effective in ameliorating TC and TG elevated by olanzapine.ConclusionsModulation of BAT activity could be a partial mechanism in reducing metabolic side effects caused by SGAs in child and adolescent patients.

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