title: Is Crohn's creeping fat an adipose tissue?
abstract: BACKGROUND
  In human pathology, the "creeping fat" (CF) of the mesentery is unique to Crohn's disease (CD). CF is usually referred to as an ectopic extension of mesenteric adipose tissue (MAT). However, since no animal model developing CF has ever been established, very little is known about this type of fat-depot expansion and its role in the development of the disease.
  
  
  METHODS
  We developed and standardized an experimental protocol in mice that reproducibly induces CF development when a severe colonic inflammation is obtained by intracolonic instillation of DNBS.
  
  
  RESULTS
  Macro-microscopic observations revealed a fatty appearance of CF. Yet when compared to MAT from the same animals, CF contains very little triglycerides, few adipocytes, and we observed a very low expression and protein levels of both adipose markers (hormone-sensitive lipase, perilipin) and adipocytokines (leptin, adiponectin). The decreased expression of perilipin in CF was also observed by immunohistochemistry. Conversely, the expression of proinflammatory and fibrous markers (Pref-1) was much higher in CF than in MAT. These observations were fully consistent with those made on CF recovered from five CD patients and compared with subcutaneous and mesenteric fat from the same patients.
  
  
  CONCLUSIONS
  Altogether, this work reports an original experimental mice model of CF. In this model we establish for the first time that CF only occurs in severe colonic inflammation and shows an inflammatory, fibrous but not an adipose pattern.
authors.affiliation: INRA, UMR 1054, Neuro-Gastroenterology & Nutrition Unit, Toulouse, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Olivier
authors.forename: Vassilia
authors.initials: V
authors.lastname: Théodorou
authors.forename: Philippe
authors.initials: P
authors.lastname: Valet
authors.forename: Isabelle
authors.initials: I
authors.lastname: Castan-Laurell
authors.forename: Hervé
authors.initials: H
authors.lastname: Guillou
authors.forename: Justine
authors.initials: J
authors.lastname: Bertrand-Michel
authors.forename: Christel
authors.initials: C
authors.lastname: Cartier
authors.forename: Valérie
authors.initials: V
authors.lastname: Bezirard
authors.forename: Robert
authors.initials: R
authors.lastname: Ducroc
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Segain
authors.forename: Guillaume
authors.initials: G
authors.lastname: Portier
authors.forename: Sylvain
authors.initials: S
authors.lastname: Kirzin
authors.forename: Jacques
authors.initials: J
authors.lastname: Moreau
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Duffas
authors.forename: Laurent
authors.initials: L
authors.lastname: Ferrier
authors.forename: Hélène
authors.initials: H
authors.lastname: Eutamène
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D015153:Blotting, Western; D001835:Body Weight; D003092:Colitis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D003424:Crohn Disease / Q000378:metabolism / Q000473:pathology*; D004139:Dinitrofluorobenzene / Q000031:analogs & derivatives / Q000633:toxicity; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007124:Immunoenzyme Techniques; D008055:Lipids; D008297:Male; D008643:Mesentery; D051379:Mice; D008807:Mice, Inbred BALB C; D009195:Peroxidase / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D008055:Lipids; D012333:RNA, Messenger; C045305:2,4-dinitrofluorobenzene sulfonic acid; D004139:Dinitrofluorobenzene; D009195:Peroxidase