title: Adipose tissue plasticity during catch-up fat driven by thrifty metabolism: relevance for muscle-adipose glucose redistribution during catch-up growth.
abstract: OBJECTIVE
  Catch-up growth, a risk factor for later type 2 diabetes, is characterized by hyperinsulinemia, accelerated body-fat recovery (catch-up fat), and enhanced glucose utilization in adipose tissue. Our objective was to characterize the determinants of enhanced glucose utilization in adipose tissue during catch-up fat.
  
  
  METHODS
  White adipose tissue morphometry, lipogenic capacity, fatty acid composition, insulin signaling, in vivo glucose homeostasis, and insulinemic response to glucose were assessed in a rat model of semistarvation-refeeding. This model is characterized by glucose redistribution from skeletal muscle to adipose tissue during catch-up fat that results solely from suppressed thermogenesis (i.e., without hyperphagia).
  
  
  RESULTS
  Adipose tissue recovery during the dynamic phase of catch-up fat is accompanied by increased adipocyte number with smaller diameter, increased expression of genes for adipogenesis and de novo lipogenesis, increased fatty acid synthase activity, increased proportion of saturated fatty acids in triglyceride (storage) fraction but not in phospholipid (membrane) fraction, and no impairment in insulin signaling. Furthermore, it is shown that hyperinsulinemia and enhanced adipose tissue de novo lipogenesis occur concomitantly and are very early events in catch-up fat.
  
  
  CONCLUSIONS
  These findings suggest that increased adipose tissue insulin stimulation and consequential increase in intracellular glucose flux play an important role in initiating catch-up fat. Once activated, the machinery for lipogenesis and adipogenesis contribute to sustain an increased insulin-stimulated glucose flux toward fat storage. Such adipose tissue plasticity could play an active role in the thrifty metabolism that underlies glucose redistribution from skeletal muscle to adipose tissue.
authors: Department of Medicine/Physiology, University of Fribourg, Fribourg, Switzerland.
authors: Serge
authors: S
authors: Summermatter
authors: Helena
authors: H
authors: Marcelino
authors: Denis
authors: D
authors: Arsenijevic
authors: Antony
authors: A
authors: Buchala
authors: Olivier
authors: O
authors: Aprikian
authors: Françoise
authors: F
authors: Assimacopoulos-Jeannet
authors: Josiane
authors: J
authors: Seydoux
authors: Jean-Pierre
authors: JP
authors: Montani
authors: Giovanni
authors: G
authors: Solinas
authors: Abdul G
authors: AG
authors: Dulloo
mesh_terms: D017667:Adipocytes / Q000378:metabolism / Q000473:pathology; D000273:Adipose Tissue / Q000254:growth & development* / Q000378:metabolism*; D000818:Animals; D001823:Body Composition; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology; D004041:Dietary Fats / Q000378:metabolism*; D004734:Energy Metabolism; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006130:Growth Disorders / Q000150:complications / Q000378:metabolism*; D006801:Humans; D006946:Hyperinsulinism / Q000378:metabolism; D008055:Lipids / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D022722:Thermogenesis
chemical_list: D004041:Dietary Fats; D008055:Lipids; D005947:Glucose