title: Characterization of brown adipose tissue in the human perirenal depot.
abstract: OBJECTIVE
  To characterize brown adipose tissue (BAT) in the human perirenal adipose tissue depot.
  
  
  METHODS
  Perirenal adipose tissue biopsies were obtained from 55 healthy kidney donors. Expression analysis was performed using microarray, real-time PCR, immunoblotting and immunohistochemistry. Additional studies using human stem cells were performed.
  
  
  RESULTS
  UCP1 gene expression analysis revealed a large intra-individual variation in the perirenal adipose tissue biopsies. Both multi- and unilocular UCP1-positive adipocytes were detected in several of the adipose tissue samples analyzed by immunohistochemical staining. Microarray analysis identified 54 genes that were overexpressed in UCP1-positive perirenal adipose tissue. Real-time PCR analysis of BAT candidate genes revealed a set of genes that were highly correlated to UCP1 and a set of three transcription factor genes (PRDM16, PGC1α, and RXRγ) that were highly correlated to each other. RXRγ displayed nuclear immunoreactivity in brown adipocytes and an increased gene expression during brown adipogenesis in human stem cells.
  
  
  CONCLUSIONS
  Our data provides the first molecular characterization of BAT in the perirenal adipose tissue depot. Furthermore, it highlights the transcription factor RXRγ as a new player in BAT development.
authors.affiliation: Department of Molecular and Clinical Medicine, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Per-Arne
authors.initials: PA
authors.lastname: Svensson
authors.forename: Kristin
authors.initials: K
authors.lastname: Lindberg
authors.forename: Jenny M
authors.initials: JM
authors.lastname: Hoffmann
authors.forename: Magdalena
authors.initials: M
authors.lastname: Taube
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Pereira
authors.forename: Tala
authors.initials: T
authors.lastname: Mohsen-Kanson
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Hafner
authors.forename: Magnus
authors.initials: M
authors.lastname: Rizell
authors.forename: Jenny
authors.initials: J
authors.lastname: Palming
authors.forename: Christian
authors.initials: C
authors.lastname: Dani
authors.forename: Maria K
authors.initials: MK
authors.lastname: Svensson
mesh_terms: D052437:Adipocytes, Brown / Q000378:metabolism*; D050156:Adipogenesis; D002001:Adipose Tissue, Brown / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism*; D007668:Kidney; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D047491:Retinoid X Receptor gamma / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000071256:Uncoupling Protein 1
chemical_list: D004268:DNA-Binding Proteins; D007473:Ion Channels; D024101:Mitochondrial Proteins; C486497:PPARGC1A protein, human; C416371:PRDM16 protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D047491:Retinoid X Receptor gamma; D014157:Transcription Factors; C000604371:UCP1 protein, human; D000071256:Uncoupling Protein 1