scholarly journals Quantifying Reductive Carboxylation Flux of Glutamine to Lipid in a Brown Adipocyte Cell Line

2008 ◽  
Vol 283 (30) ◽  
pp. 20621-20627 ◽  
Author(s):  
Hyuntae Yoo ◽  
Maciek R. Antoniewicz ◽  
Gregory Stephanopoulos ◽  
Joanne K. Kelleher
2019 ◽  
Author(s):  
Dagmar Kindler ◽  
Isabel S Sousa ◽  
Sabine Schweizer ◽  
Sarah Lerch ◽  
Martin Klingenspor ◽  
...  

AbstractMolecular pathways regulating brown adipocyte formation and metabolism can be exploited as targets for the treatment of obesity and disorders of glucose and lipid metabolism such as type-2 diabetes. Investigations in this direction require adequate cell models for brown adipocytes and their precursors. We report the establishment of a novel clonal cell line derived from defined Lin−Sca1+ adipocyte precursors from murine interscapular brown fat. In contrast to most currently available lines, immortalization was achieved by serial passaging without viral or genetic manipulation. Instead, the media were supplemented with basic fibroblast growth factor, which was required for the maintenance of stable long-term growth and immature morphology. BATkl2 cells differentiated to adipocytes with high efficiency upon standard adipogenic induction independently of PPARg agonists and even at higher passage numbers. BATkl2 adipocytes showed readily detectable Uncoupling protein 1 (Ucp1) protein expression and acutely responded to norepinephrine with increased Ucp1 mRNA expression, lipolysis and uncoupled mitochondrial respiration. Highly efficient siRNA-mediated knockdown was demonstrated in the growth state as well as in differentiating adipocytes, whereas plasmid DNA transfection was achieved in immature cells. These features make the BATkl2 cell line an attractive brown (pre)-adipocyte cell model.


1994 ◽  
Vol 107 (1) ◽  
pp. 313-319 ◽  
Author(s):  
S. Klaus ◽  
L. Choy ◽  
O. Champigny ◽  
A.M. Cassard-Doulcier ◽  
S. Ross ◽  
...  

The HIB 1B cell line, derived from a brown fat tumor of a transgenic mouse, is the first established brown adipocyte cell line capable of expressing the brown fat-specific mitochondrial uncoupling protein (UCP). UCP gene expression, which was virtually undetectable under basic conditions, was stimulated by acute catecholamine or cyclic AMP treatment to levels comparable to primary cultures of brown adipocytes. Elevation of UCP mRNA levels following stimulation was very rapid but transient, decreasing after about 4 hours with a half-life between 9 and 13 hours. Immunoblotting showed the presence of UCP in HIB 1B mitochondria, but expression was much lower than observed in BAT or primary cultures of brown adipocytes. Upon transfection of HIB 1B cells with a reporter gene containing the UCP promoter, the activity of the transgene was regulatable by cAMP and norepinephrine. Investigation of the possible adrenergic receptors involved in UCP stimulation showed that specific beta 3-adrenergic agonists were much less effective than nonspecific beta-adrenergic agonists and that mRNA levels of the atypical, fat-specific beta 3-adrenoceptor were lower than those observed in brown adipocytes differentiated in primary culture. From pharmacological evidence we conclude that beta 3-adrenergic receptors account for approximately 30–40% of catecholamine induced UCP gene stimulation, whereas about 60–70% is stimulated via the classical beta 1/2 adrenergic pathway. We conclude that HIB 1B cells represent a functional system for the study of mechanisms related to brown adipose thermogenesis.


2019 ◽  
Vol 17-18 ◽  
pp. 100282
Author(s):  
Haotong Chen ◽  
Yong Han ◽  
Ishrat Jahan ◽  
Shiyong Wu ◽  
Brian C. Clark ◽  
...  

1996 ◽  
Vol 317 (3) ◽  
pp. 827-833 ◽  
Author(s):  
Pere PUIGSERVER ◽  
Francisca VÁZQUEZ ◽  
María L. BONET ◽  
Catalina PICÓ ◽  
Andreu PALOU

The effects of retinoic acid (RA) isomers (all-trans-RA and 9-cis-RA) on the appearance of uncoupling protein (UCP; thermogenin), the only unequivocal molecular marker of the brown adipocyte differentiated phenotype, have been investigated in primary cultures of brown adipocytes, in the brown adipocyte cell line HIB 1B and directly in intact mice. The results obtained with cultured cells indicate that retinoids function as inducers of the appearance of UCP and, at the same time, partially inhibit brown adipocyte cell proliferation. The two RA isomers displayed similar effectiveness as UCP inducers, their effect being comparable with that triggered by noradrenaline, so far considered to be the main modulator of UCP gene expression. The effectiveness of retinoids as UCP inducers was dependent on the stage of brown adipocyte differentiation, being maximal in confluent primary cells and in the medium–late differentiation stage of HIB 1B cells. Corroborating the results obtained in vitro, we show that administration of all-trans-RA or 9-cis-RA to mice leads to an increase in their brown adipose tissue specific UCP content. 9-cis-RA treatment also prevented the loss of UCP on cold deacclimation. To our knowledge, this is the first report of a stimulatory effect of retinoid compounds on UCP induction in vivo.


2001 ◽  
Vol 356 (2) ◽  
pp. 659-664 ◽  
Author(s):  
Karine MOULIN ◽  
Nathalie TRUEL ◽  
Mireille ANDRÉ ◽  
Emmanuelle ARNAULD ◽  
Maryse NIBBELINK ◽  
...  

In mammals, two types of adipose tissue are present, brown and white. They develop sequentially, as brown fat occurs during late gestation whereas white fat grows mainly after birth. However, both tissues have been shown to have great plasticity. Thus an apparent transformation of brown fat into white fat takes place during post-natal development. This observation raises questions about a possible conversion of brown into white adipocytes during development, although indirect data argue against this hypothesis. To investigate such questions in vivo, we generated two types of transgenic line. The first carried a transgene expressing Cre recombinase specifically in brown adipocytes under the control of the rat UCP1 promoter. The second corresponded to an inactive lacZ gene under the control of the human cytomegalovirus promoter. This dormant gene is inducible by Cre because it contains a Stop sequence between two loxP sequences, separating the promoter from the coding sequence. Adipose tissues of progeny derived by crossing independent lines established from both constructs were investigated. LacZ mRNA corresponding to the activated reporter gene was easily detected in brown fat and not typically in white fat, even by reverse transcriptase PCR experiments. These data represent the first direct experimental proof that, during normal development, most white adipocytes do not derive from brown adipocytes.


Endocrinology ◽  
2013 ◽  
Vol 154 (9) ◽  
pp. 2992-3000 ◽  
Author(s):  
Marta Giralt ◽  
Francesc Villarroya

Brown adipose tissue (BAT) is a major site of nonshivering thermogenesis in mammals. Rodent studies indicated that BAT thermogenic activity may protect against obesity. Recent findings using novel radiodiagnosis procedures revealed unanticipated high activity of BAT in adult humans. Moreover, complex processes of cell differentiation leading to the appearance of active brown adipocytes have been recently identified. The brown adipocytes clustered in defined anatomical BAT depots of rodents arise from mesenchymal precursor cells common to the myogenic cell lineage. They are being called “classical” or “developmentally programmed” brown adipocytes. However, brown adipocytes may appear after thermogenic stimuli at anatomical sites corresponding to white adipose tissue (WAT). This process is called the “browning” of WAT. The brown adipocytes appearing in WAT derive from precursor cells different from those in classical BAT and are closer to the white adipocyte cell lineage. The brown adipocytes appearing in WAT are often called “inducible, beige, or brite.” The appearance of these inducible brown adipocytes in WAT may also involve transdifferentiation processes of white-to-brown adipose cells. There is no evidence that the ultimate thermogenic function of the beige/brite adipocytes differs from that of classical brown adipocytes, although some genetic data in rodents suggest a relevant role of the browning process in protection against obesity. Although the activation of classical BAT and the browning process share common mechanisms of induction (eg, noradrenergic-mediated induction by cold), multiple novel adrenergic-independent endocrine factors that activate BAT and the browning of WAT have been identified recently. In adult humans, BAT is mainly composed of beige/brite adipocytes, although recent data indicate the persistence of classical BAT at some anatomical sites. Understanding the biological processes controlling brown adipocyte activity and differentiation could help the design of BAT-focused strategies to increase energy expenditure and fight against obesity.


2000 ◽  
Vol 279 (2) ◽  
pp. E386-E394 ◽  
Author(s):  
Patrice Penfornis ◽  
Say Viengchareun ◽  
Damien Le Menuet ◽  
Françoise Cluzeaud ◽  
Maria-Christina Zennaro ◽  
...  

By use of targeted oncogenesis, a brown adipocyte cell line was derived from a hibernoma of a transgenic mouse carrying the proximal promoter of the human mineralocorticoid receptor (MR) linked to the SV40 large T antigen. T37i cells remain capable of differentiating into brown adipocytes upon insulin and triiodothyronine treatment as judged by their ability to express uncoupling protein 1 and maintain MR expression. Aldosterone treatment of undifferentiated cells induced accumulation of intracytoplasmic lipid droplets and mitochondria. This effect was accompanied by a significant and dose-dependent increase in intracellular triglyceride content (half-maximally effective dose 10−9 M) and involved MR, because it was unaffected by RU-38486 treatment but was totally abolished in the presence of aldosterone antagonists (spironolactone, RU-26752). The expression of early adipogenic gene markers, such as lipoprotein lipase, peroxisome proliferator-activated receptor-γ, and adipocyte-specific fatty acid binding protein 2, was enhanced by aldosterone, confirming activation of the differentiation process. We demonstrate that, in the T37i cell line, aldosterone participates in the very early induction of brown adipocyte differentiation. Our findings may have a broader biological significance and suggest that MR is not only implicated in maintaining electrolyte homeostasis but could also play a role in metabolism and energy balance.


Endocrinology ◽  
1994 ◽  
Vol 134 (2) ◽  
pp. 906-913 ◽  
Author(s):  
U C Kozak ◽  
L P Kozak

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