scholarly journals Expression of interleukin-1α and interleukin-1 receptor type I genes in murine brown adipose tissue

FEBS Letters ◽  
1993 ◽  
Vol 334 (2) ◽  
pp. 229-232 ◽  
Author(s):  
Ladislav Burýs̆ek ◽  
Petr Tvrdí ◽  
Josef Hous̆tĕk
2002 ◽  
Vol 283 (5) ◽  
pp. E980-E987 ◽  
Author(s):  
Philippe Cettour-Rose ◽  
Albert G. Burger ◽  
Christoph A. Meier ◽  
Theo J. Visser ◽  
Françoise Rohner-Jeanrenaud

To assess whether intracerebroventricular leptin administration affects monodeiodinase type II (D2) activity in the tissues where it is expressed [cerebral cortex, hypothalamus, pituitary, and brown adipose tissue (BAT)], hepatic monodeiodinase type I (D1) activity was inhibited with propylthiouracil (PTU), and small doses of thyroxine (T4; 0.6 nmol · 100 g body wt−1 · day−1) were supplemented to compensate for the PTU-induced hypothyroidism. Two groups of rats were infused with leptin for 6 days, one of them being additionally treated with reverse triiodothyronine (rT3), an inhibitor of D2. Control rats were infused with vehicle and pair-fed the amount of food consumed by leptin-infused animals. Central leptin administration produced marked increases in D2 mRNA expression and activity in BAT, changes that were likely responsible for increased plasma T3 and decreased plasma T4 levels. Indeed, plasma T3 and T4 concentrations were unaltered by central leptin administration in the presence of rT3. The additional observation of a leptin-induced increased mRNA expression of BAT uncoupling protein-1 suggested that the effect on BAT D2 may be mediated by the sympathetic nervous system.


1991 ◽  
Vol 261 (2) ◽  
pp. E257-E261
Author(s):  
S. Y. Wu ◽  
J. K. Kim ◽  
I. J. Chopra ◽  
Y. Murata ◽  
D. A. Fisher

We have recently shown that ovine fetal brown adipose tissue (BAT) contains two distinct iodothyronine 5'-monodeiodinase (5'MDI) activities, one with a high Km (type I) and another with a low Km (type II). Both activities increased to maximum levels near term (150 days gestation). BAT plays a major role in neonatal temperature regulation in lambs, and available evidence suggests that BAT 5'MDI activity is closely linked to thermogenic capacity. To better characterize the changes in 5'MDI after birth, we studied both type I and type II 5'MDI in lamb BAT from the time of birth to 30 days of postnatal age. Type I 5'MDI activity [pmol 3,5,3'-triiodothyronine (T3).mg protein-1.h-1] showed no significant changes during the first 11 days after birth [newborn (NB), 95 +/- 16; 1 day, 83 +/- 20; 3-4 days, 80 +/- 11; 10-11 days, 92 +/- 28]. Activity decreased significantly at 30 days (24 +/- 8.9, P less than 0.05). On the other hand, the type II 5'MDI activity (fmol I- released.mg protein-1.h-1) increased significantly (P less than 0.01) during the first 4 days, (NB, 348 +/- 23; 1 day, 679 +/- 37; 3-4 days, 785 +/- 199), decreased toward NB values (401 +/- 87) at 10-11 days of age, and fell to 66 +/- 31 at 30 days (P less than 0.05 vs. NB). Kinetic analysis of BAT type II thyroxine 5'MDI revealed a rise in maximum velocity from NB to 1 and 3-4 days of age without a change in the enzymatic activity Km.(ABSTRACT TRUNCATED AT 250 WORDS)


1958 ◽  
Vol 4 (3) ◽  
pp. 287-290 ◽  
Author(s):  
J. D. Lever ◽  
J. B. Chappell

Mitochondrial fractions, relatively free from contamination by other cytoplasmic structures, have been isolated by differential centrifugation from homogenates of brown adipose tissue from starved rats. It was possible in such fractions to distinguish two types of mitochondria in this tissue. Type I mitochondria, when morphologically intact, are limited by a bilaminar membrane and show regular parallel cristae. In isolated fractions, a proportion of these mitochondria are swollen, vacuolation occurring within the cristae between their limiting membranes. Type II mitochondria are distinguished from the more numerous type I bodies by the opaque appearance of their matrix. They are limited by a membrane which is in part single, and in part double. They show a few, but crisply outlined internal membranes. Vacuolation of this type of mitochondrion has not been observed. Vacuolation comparable to that in brown fat mitochondria was also observed between the two laminae of the enclosing membrane and within the cristae of liver mitochondria.


2011 ◽  
Vol 36 (3) ◽  
pp. 313-322 ◽  
Author(s):  
Sarah J. Ehlers ◽  
Stephanie M. Larson ◽  
Heather E. Rasmussen ◽  
Young-Ki Park ◽  
Ji-Young Lee

Obese and diabetic humans display decreased plasma high-density lipoprotein cholesterol (HDL-C) concentrations and an increased risk for coronary heart disease. However, investigation on HDL metabolism in obesity with a particular emphasis on hepatic ATP-binding cassette transporter A1 (ABCA1), the primary factor for HDL formation, has not been well studied. Human apolipoprotein B100transgenic (hApoBtg) and brown adipose tissue deficient (BATless) mice were crossed to generate hApoBtg/BATless mice. Male and female hApoBtgand hApoBtg/BATless mice were maintained on either a regular rodent chow diet or a diet high in fat and cholesterol until 24 weeks of age. The hApoBtg/BATless mice that were fed a HF/HC diet became obese, developed hepatic steatosis, and had significantly elevated plasma insulin levels compared with their hApoBtgcounterparts, but plasma concentrations of total cholesterol, HDL-C, triglycerides, and free fatty acids and lipoprotein distribution between genotypes were not significantly different. Hepatic expression of genes encoding HDL-modifying factors (e.g., scavenger receptor, class B, type I, hepatic lipase, lecithin:cholesterol acyltransferase, and phospholipid transfer protein) was either altered significantly or showed a trend of difference between 2 genotypes of mice. Importantly, hepatic protein levels of ABCA1 were significantly lowered by ∼35% in male obese hApoBtg/BATless mice with no difference in mRNA levels compared with hApoBtgcounterparts. Despite reduced hepatic ABCA1 protein levels, plasma HDL-C concentrations were not altered in male obese hApoBtg/BATless mice. The result suggests that hepatic ABCA1 may not be a primary contributing factor for perturbations in HDL metabolism in obesity-induced hyperinsulinemia.


1997 ◽  
Vol 77 (6) ◽  
pp. 871-883 ◽  
Author(s):  
Lynne Clarke ◽  
Michael J. Bryant ◽  
Michael A. Lomax ◽  
Michael E. Symonds

AbstractWe examined the effect of maternal chronic cold exposure, induced by winter-shearing ewes 4 weeks before their predicted lambing date, on brown adipose tissue (BAT) and liver development in lambs. Fetuses were sampled from under-fed (60% of energy requirements for maintenance and pregnancy of an unshorn ewe) shorn or unshorn ewes at 126,140 and 145 d of gestation. Lambs were sampled from ewes within 2 h of birth. Throughout gestation fetal body, BAT and liver weights were similar in shorn and unshorn groups. The level of GDP binding to mitochondrial uncoupling protein remained low throughout gestation, but increased dramatically after birth. Lambs born to shorn ewes possesd more mitochondrial protein and exhibited a significantly higher total thermogenic activity in BAT. Type I iodothyronine 5 deiodinas(EC 3.8.1.4) activity in BAT peaked at birth, as did hepatic iodothyronine Sdeiodinase activity and was significantly greater in lambs born to under-fed shorn ewes, which exhibited a higher plasma triiodothyronine concentration. Chronic maternal adaptations to prolonged cold exposure appear to enable pregnant ewes to compensate for the negative effects of under-feeding on fetal growth and development


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Jimmy Berbée ◽  
Mariëtte R Boon ◽  
Padmini P Khedoe ◽  
Alexander Bartelt ◽  
Sander Kooijman ◽  
...  

Objectives: Brown adipose tissue (BAT) recently emerged as a novel player in lipoprotein metabolism. BAT combusts high amounts fatty acids into heat resulting in reduced plasma triglyceride (TG) levels as well as obesity. However, the precise role of BAT in cholesterol metabolism and atherosclerosis development remains unclear. We aimed to assess the effect of stimulating BAT activity by ß3-adrenergic receptor (ß3-AR) agonism on lipoprotein metabolism and atherosclerosis development in APOE*3-Leiden.CETP mice, a well-established model for human-like lipoprotein metabolism. Methods and results: Mice were fed a Western-type diet to induce dyslipidemia and were treated subcutaneously with the selective ß3-AR agonist CL316243 (3x20 μg/week) or vehicle for 10 weeks. ß3-AR agonism reduced total fat mass (-59%) and white adipose tissue (WAT) pad size (-40%). ß3-AR agonism decreased the size of intracellular lipid vacuoles in BAT, and increased UCP-1 expression in WAT, indicating activation of brown adipocytes ( i.e. BAT) as well as their precursors ( i.e. WAT). These effects were accompanied by increased uptake of glycerol tri[ 3 H]oleate from VLDL-like particles by BAT (+125%) and by WAT (+120%) as well as fatty acid oxidation (+25%) as determined by indirect calorimetry. In line with these data, activation of BAT decreased plasma levels of TG (-46%) and (V)LDL-cholesterol (-24%) and increased HDL-cholesterol (+23%), accompanied by increased reverse cholesterol transport (+2.5-fold). As a consequence of improving lipoprotein metabolism, BAT activation reduced atherosclerosis development (-43%) as well as lesion severity, indicated by more mild type I-III lesions (+64%) and reduced severe type IV-V lesions (-66%), in the aortic root. These effects were dependent on a functional hepatic apoE-LDLr clearance pathway, as BAT activation in apoe -/- and ldlr -/- mice lowered plasma TG levels but did not attenuate hypercholesterolemia and atherosclerosis Conclusion: We demonstrate that activation of BAT via the ß3-AR is a powerful tool to reduce dyslipidemia and protect against atherosclerosis. These findings indicate that activation of BAT is a promising novel strategy to combat dyslipidemia and cardiovascular disease.


2020 ◽  
Vol 477 (7) ◽  
pp. 1261-1286 ◽  
Author(s):  
Marie Anne Richard ◽  
Hannah Pallubinsky ◽  
Denis P. Blondin

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.


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