title: Regionalization of browning revealed by whole subcutaneous adipose tissue imaging.
abstract: White and brown adipose tissues play a major role in the regulation of metabolic functions. With the explosion of obesity and metabolic disorders, the interest in adipocyte biology is growing constantly. While several studies have demonstrated functional differences between adipose fat pads, especially in their involvement in metabolic diseases, there are no data available on possible heterogeneity within an adipose depot.
  
  
  
  This study investigated the three-dimensional (3-D) organization of the inguinal fat pad in adult mice by combining adipose tissue clearing and autofluorescence signal acquisition by confocal microscopy. In addition, the study analyzed the expression of genes involved in adipocyte biology and browning at the mARN and protein levels in distinct areas of the inguinal adipose tissue, in control conditions and after cold exposure.
  
  
  
  Semiautomated 3-D image analysis revealed an organization of the fat depot showing two regions: the core was structured into segmented lobules, whereas the periphery appeared unsegmented. Perilipin immunostaining showed that most of the adipocytes located in the core region had smaller lipid droplets, suggesting a brown-like phenotype. qPCR analysis showed a higher expression of the browning markers Ucp1, Prdm16, Ppargc1a, and Cidea in the core region than at the periphery. Finally, cold exposure induced upregulation of thermogenic gene expression associated with an increase of UCP1 protein, specifically in the core region of the inguinal fat depot.
  
  
  
  Altogether, these data demonstrate a structural and functional heterogeneity of the inguinal fat pad, with an anatomically restricted browning process in the core area.
authors.affiliation: Stromalab, Université de Toulouse, CNRS, EFS, INSERM, UPS, Toulouse, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Barreau
authors.affiliation: Stromalab, Université de Toulouse, CNRS, EFS, INSERM, UPS, Toulouse, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Labit
authors.affiliation: Stromalab, Université de Toulouse, CNRS, EFS, INSERM, UPS, Toulouse, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Guissard
authors.affiliation: Institut des Techniques Avancées du Vivant, Université de Toulouse, CNRS, UPS, Toulouse, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Rouquette
authors.affiliation: Institut des Techniques Avancées du Vivant, Université de Toulouse, CNRS, UPS, Toulouse, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Boizeau
authors.affiliation: Institut des Techniques Avancées du Vivant, Université de Toulouse, CNRS, UPS, Toulouse, France.
authors.forename: Souleymane
authors.initials: S
authors.lastname: Gani Koumassi
authors.affiliation: Stromalab, Université de Toulouse, CNRS, EFS, INSERM, UPS, Toulouse, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Carrière
authors.affiliation: Stromalab, Université de Toulouse, CNRS, EFS, INSERM, UPS, Toulouse, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Jeanson
authors.affiliation: Stromalab, Université de Toulouse, CNRS, EFS, INSERM, UPS, Toulouse, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Berger-Müller
authors.affiliation: Stromalab, Université de Toulouse, CNRS, EFS, INSERM, UPS, Toulouse, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Dromard
authors.affiliation: Institut de Mécanique des Fluides, Université de Toulouse, INPT, UPS, Toulouse, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Plouraboué
authors.affiliation: Stromalab, Université de Toulouse, CNRS, EFS, INSERM, UPS, Toulouse, France.
authors.forename: Louis
authors.initials: L
authors.lastname: Casteilla
authors.affiliation: Stromalab, Université de Toulouse, CNRS, EFS, INSERM, UPS, Toulouse, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Lorsignol
mesh_terms: D017667:Adipocytes / Q000166:cytology; D002001:Adipose Tissue, Brown / Q000033:anatomy & histology* / Q000502:physiology; D050154:Adiposity; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D009765:Obesity; D061848:Optical Imaging; D050151:Subcutaneous Fat / Q000033:anatomy & histology* / Q000737:chemistry / Q000502:physiology; D022722:Thermogenesis; D000071256:Uncoupling Protein 1 / Q000032:analysis
chemical_list: D015415:Biomarkers; C000604372:Ucp1 protein, mouse; D000071256:Uncoupling Protein 1