PPARalpha 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), p.146-151
• Main Authors: Waldén, Tomas B, Petrovic, Natasa, Nedergaard, Jan
• Format: Article
• Language: English
• Subjects: Adipocytes, Brown - metabolism; Animals; Biologi; Biology; DNA-Binding Proteins - genetics; Female; Gene Expression Regulation; Genetic Markers - genetics; Homeodomain Proteins - genetics; Ion Channels - genetics; LIM-Homeodomain Proteins; Male; Mice; Mice, Mutant Strains; Mitochondrial Proteins - genetics; Muscle Development - genetics; Muscle, Skeletal - metabolism; NATURAL SCIENCES; NATURVETENSKAP; PPAR alpha - genetics; PPAR alpha - metabolism; Transcription Factors - genetics; Uncoupling Protein 1
• ISSN: 1090-2104; 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2010.05.053

Brown adipocytes and myocytes develop from a common adipomyocyte precursor. PPARalpha is a nuclear receptor important for lipid and glucose metabolism. It has been suggested that in brown adipose tissue, PPARalpha 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 PPARalpha in these processes, we measured expression of muscle-associated genes in brown adipose tissue and brown adipocytes from PPARalpha-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 PPARalpha, nor by the PPARalpha 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 PPARalpha. Thus, it would not seem that PPARalpha represses muscle-associated genes, but PPARalpha may still play a role in the regulation of the bifurcation of the adipomyocyte precursor into a brown adipocyte or myocyte phenotype.