PPAR{alpha} does not suppress muscle-associated gene expression in brown adipocytes but does influence expression of factors that fingerprint the brown adipocyte

• Published in: Biochemical and biophysical research communications 2010-06, Vol.397 (2)
• Main Authors: Walden, Tomas B., Petrovic, Natasa, Nedergaard, Jan
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; ADIPOSE TISSUE; GENES; GLUCOSE; LIPIDS; METABOLISM; MICE; MUSCLES; PHENOTYPE; RECEPTORS
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/J.BBRC.2010.05.053

Brown adipocytes and myocytes develop from a common adipomyocyte precursor. PPAR{alpha} is a nuclear receptor important for lipid and glucose metabolism. It has been suggested that in brown adipose tissue, PPAR{alpha} represses the expression of muscle-associated genes, in this way potentially acting to determine cell fate in brown adipocytes. To further understand the possible role of PPAR{alpha} in these processes, we measured expression of muscle-associated genes in brown adipose tissue and brown adipocytes from PPAR{alpha}-ablated mice, including structural genes (Mylpf, Tpm2, Myl3 and MyHC), regulatory genes (myogenin, Myf5 and MyoD) and a myomir (miR-206). However, in our hands, the expression of these genes was not influenced by the presence or absence of PPAR{alpha}, nor by the PPAR{alpha} activator Wy-14,643. Similarly, the expression of genes common for mature brown adipocyte and myocytes (Tbx15, Meox2) were not affected. However, the brown adipocyte-specific regulatory genes Zic1, Lhx8 and Prdm16 were affected by PPAR{alpha}. Thus, it would not seem that PPAR{alpha} represses muscle-associated genes, but PPAR{alpha} may still play a role in the regulation of the bifurcation of the adipomyocyte precursor into a brown adipocyte or myocyte phenotype.