title: Unmanipulated native fat exposed to high-energy diet, but not autologous grafted fat by itself, may lead to overexpression of Ki67 and PAI-1.
abstract: BACKGROUND
  Although its unclear oncological risk, which led to more than 20 years of prohibition of its use, fat grafting to the breast is widely used nowadays even for aesthetic purposes. Thus, we proposed an experimental model in rats to analyze the inflammatory activity, cellular proliferation and levels of Plasminogen Activator Inhibitor (PAI-1) in grafted fat, and in native fat exposed to high-energy diet in order to study the oncological potential of fat tissue.
  
  
  METHODS
  Samples of grafted fat of rats on regular-energy diet were compared with paired samples of native fat from the same rat on regular-energy diet and on high-energy diet in a different time. Analysis involved microscopic comparisons using hematoxylin-eosin staining, immunohistochemistry with anti-CD68-labelled macrophages, and gene expression of Ki-67 and PAI-1.
  
  
  RESULTS
  Hematoxylin-eosin staining analyses did not find any atypical cellular infiltration or unusual tissue types in the samples of grafted fat. The inflammatory status, assessed through immunohistochemical identification of CD68-labelled macrophages, was similar among samples of native fat and grafted fat of rat on regular-energy diet and of native fat of rats on high-energy diet. Real-time PCR revealed that high-energy diet, but not fat grafting, leads to proliferative status on adipose tissue (overexpression of ki-67, p = 0.046) and raised its PAI-1 levels, p < 0.001.
  
  
  CONCLUSIONS
  While the native adipose tissue overexpressed PAI-1 and KI67 when exposed to high-energy diet, the grafted fat by itself was unable to induce cellular proliferation, chronic inflammatory activity and/or elevation of PAI-1 levels.
authors.affiliation: Department of Gynecology and Obstetrics at School of Medical Sciences, State University of Campinas (UNICAMP), R. Alexander Fleming, 101, Campinas, SP 13083-881 Brazil ; Santa Cruz Plastic Surgery Institute (ICPSC), São Paulo, SP Brazil.
authors.forename: Francisco
authors.initials: F
authors.lastname: Claro
authors.affiliation: Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas (UNICAMP), Campinas, SP Brazil.
authors.forename: Joseane
authors.initials: J
authors.lastname: Morari
authors.affiliation: Laboratory of Specialized Pathology, School of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP Brazil.
authors.forename: Luciana R
authors.initials: LR
authors.lastname: Moreira
authors.affiliation: Department of Gynecology and Obstetrics at School of Medical Sciences, State University of Campinas (UNICAMP), R. Alexander Fleming, 101, Campinas, SP 13083-881 Brazil.
authors.forename: Luís O Z
authors.initials: LO
authors.lastname: Sarian
authors.affiliation: Laboratory of Specialized Pathology, School of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP Brazil.
authors.forename: Glauce A
authors.initials: GA
authors.lastname: Pinto
authors.affiliation: Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas (UNICAMP), Campinas, SP Brazil.
authors.forename: Licio A
authors.initials: LA
authors.lastname: Velloso
authors.affiliation: Department of Gynecology and Obstetrics at School of Medical Sciences, State University of Campinas (UNICAMP), R. Alexander Fleming, 101, Campinas, SP 13083-881 Brazil.
authors.forename: Aarão M
authors.initials: AM
authors.lastname: Pinto-Neto
keywords: Breast cancer; CD68; Fat grafting; Ki67; Lipofilling; PAI-1