Chronic Peroxisome Proliferator-activated Receptor γ (PPARγ) Activation of Epididymally Derived White Adipocyte Cultures Reveals a Population of Thermogenically Competent, UCP1-containing Adipocytes Molecularly Distinct from Classic Brown Adipocytes

摘要: The recent insight that brown adipocytes and muscle cells share a common origin in this respect are distinct from white has spurred questions concerning the molecular characteristics of UCP1-expressing observed classic adipose tissue depots under certain physiological or pharmacological conditions. Examining precursors purest depot (epididymal), we report here chronic treatment with peroxisome proliferator-activated receptor γ agonist rosiglitazone promotes not only expression PGC-1α mitochondriogenesis these but also norepinephrine-augmentable UCP1 gene significant subset cells, providing genuine thermogenic capacity. However, although functional genes expressed, devoid transcripts for novel transcription factors now associated (Zic1, Lhx8, Meox2, characteristically PRDM16) myocyte-associated (myogenin myomirs (muscle-specific microRNAs)) retain fat such as Hoxc9 expression. Co-culture experiments verify proliferating (adipomyocytes), therefore constitute ("brite" adipocytes) developmental distinguishing them separate class cells.