scholarly journals Rhein Protects against Obesity and Related Metabolic Disorders through Liver X Receptor-Mediated Uncoupling Protein 1 Upregulation in Brown Adipose Tissue

2012 ◽  
Vol 8 (10) ◽  
pp. 1375-1384 ◽  
Author(s):  
Xiaoyan Sheng ◽  
Xuehua Zhu ◽  
Yuebo Zhang ◽  
Guoliang Cui ◽  
Linling Peng ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Metabolic Disorders ◽  
Uncoupling Protein ◽  
Liver X Receptor ◽  
Uncoupling Protein 1 ◽  
Brown Adipose

scholarly journals Liver X Receptor α Is a Transcriptional Repressor of the Uncoupling Protein 1 Gene and the Brown Fat Phenotype

2008 ◽  
Vol 28 (7) ◽  
pp. 2187-2200 ◽  
Author(s):  
Haibo Wang ◽  
Yuan Zhang ◽  
Einav Yehuda-Shnaidman ◽  
Alexander V. Medvedev ◽  
Naresh Kumar ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Liver X Receptor ◽  
Peroxisome Proliferator ◽  
Uncoupling Protein 1 ◽  
Peroxisome Proliferator Activated Receptor ◽  
Mechanism Of Inhibition ◽  
Brown Adipose ◽  
Liver X Receptor Α

ABSTRACT The adipocyte integrates crucial information about metabolic needs in order to balance energy intake, storage, and expenditure. Whereas white adipose tissue stores energy, brown adipose tissue is a major site of energy dissipation through adaptive thermogenesis mediated by uncoupling protein 1 (UCP1) in mammals. In both white and brown adipose tissue, nuclear receptors and their coregulators, such as peroxisome proliferator-activated receptor γ (PPARγ) and PPARγ coactivator 1α (PGC-1α), play key roles in regulating their development and metabolic functions. Here we show the unexpected role of liver X receptor α (LXRα) as a direct transcriptional inhibitor of β-adrenergic receptor-mediated, cyclic AMP-dependent Ucp1 gene expression through its binding to the critical enhancer region of the Ucp1 promoter. The mechanism of inhibition involves the differential recruitment of the corepressor RIP140 to an LXRα binding site that overlaps with the PPARγ/PGC-1α response element, resulting in the dismissal of PPARγ. The ability of LXRα to dampen energy expenditure in this way provides another mechanism for maintaining a balance between energy storage and utilization.

scholarly journals Uncoupling protein 1 binds one nucleotide per monomer and is stabilized by tightly bound cardiolipin

2015 ◽  
Vol 112 (22) ◽  
pp. 6973-6978 ◽  
Author(s):  
Yang Lee ◽  
Chrissie Willers ◽  
Edmund R. S. Kunji ◽  
Paul G. Crichton
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Size Exclusion ◽  
Uncoupling Protein 1 ◽  
Mitochondrial Carriers ◽  
Mitochondrial Inner Membrane ◽  
Brown Adipose ◽  
Integral Role ◽  
Covalent Chromatography

Uncoupling protein 1 (UCP1) catalyzes fatty acid-activated, purine nucleotide-sensitive proton leak across the mitochondrial inner membrane of brown adipose tissue to produce heat, and could help combat obesity and metabolic disease in humans. Studies over the last 30 years conclude that the protein is a dimer, binding one nucleotide molecule per two proteins, and unlike the related mitochondrial ADP/ATP carrier, does not bind cardiolipin. Here, we have developed novel methods to purify milligram amounts of UCP1 from native sources by using covalent chromatography that, unlike past methods, allows the protein to be prepared in defined conditions, free of excess detergent and lipid. Assessment of purified preparations by TLC reveal that UCP1 retains tightly bound cardiolipin, with a lipid phosphorus content equating to three molecules per protein, like the ADP/ATP carrier. Cardiolipin stabilizes UCP1, as demonstrated by reconstitution experiments and thermostability assays, indicating that the lipid has an integral role in the functioning of the protein, similar to other mitochondrial carriers. Furthermore, we find that UCP1 is not dimeric but monomeric, as indicated by size exclusion analysis, and has a ligand titration profile in isothermal calorimetric measurements that clearly shows that one nucleotide binds per monomer. These findings reveal the fundamental composition of UCP1, which is essential for understanding the mechanism of the protein. Our assessment of the properties of UCP1 indicate that it is not unique among mitochondrial carriers and so is likely to use a common exchange mechanism in its primary function in brown adipose tissue mitochondria.

Tea catechins enhance the mRNA expression of uncoupling protein 1 in rat brown adipose tissue

2008 ◽  
Vol 19 (12) ◽  
pp. 840-847 ◽  
Author(s):  
Sachiko Nomura ◽  
Takashi Ichinose ◽  
Manabu Jinde ◽  
Yu Kawashima ◽  
Kaoru Tachiyashiki ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Mrna Expression ◽  
Uncoupling Protein ◽  
Uncoupling Protein 1 ◽  
Tea Catechins ◽  
Brown Adipose
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