Twist-1 is a PPARdelta-inducible, negative-feedback regulator of PGC-1alpha in brown fat metabolism.
Brown fat is specialized for energy expenditure, a process that is principally controlled by the transcriptional coactivator PGC-1alpha. Here, we describe a molecular network important for PGC-1alpha function and brown fat metabolism. We find that twist-1 is selectively expressed in adipose tissue, interacts with PGC-1alpha, and is recruited to the promoters of PGC-1alpha's target genes to suppress mitochondrial metabolism and uncoupling. In vivo, transgenic mice expressing twist-1 in the adipose tissue are prone to high-fat-diet-induced obesity, whereas twist-1 heterozygous knockout mice are obesity resistant. These phenotypes are attributed to their altered mitochondrial metabolism in the brown fat. Interestingly, the nuclear receptor PPARdelta not only mediates the actions of PGC-1alpha but also regulates twist-1 expression, suggesting a negative-feedback regulatory mechanism. These findings reveal an unexpected physiological role for twist-1 in the maintenance of energy homeostasis and have important implications for understanding metabolic control and metabolic diseases.
Pan
Dongning
D
Program in Gene Function and Expression and Program in Molecular Medicine, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
Fujimoto
Masaki
M
Lopes
Andrea
A
Wang
Yong-Xu
YX
D017667:Adipocytes / Q000378:metabolism; D002001:Adipose Tissue, Brown / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D004734:Energy Metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008928:Mitochondria / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism; D047494:PPAR delta / Q000235:genetics / Q000378:metabolism; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors; D051879:Twist-Related Protein 1 / Q000378:metabolism*
D006657:Histones; D009687:Nuclear Proteins; D047494:PPAR delta; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C485290:Ppargc1a protein, mouse; C103173:TWIST1 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D051879:Twist-Related Protein 1