title: The Appearance of a Leptin Effect on Glucose Absorption in Caco2 Cells Depends on Their Differentiation Level.
abstract: Backdround/Aims: The aim of this work was to study the effect and mechanism of action of leptin added apically, on glucose absorption, using Caco-2 cells as a model.
  
  
  METHODS
  Cells were grown on inserts and treated with leptin, at different time points after confluence. Radiolabelled glucose was added to the upper chamber and samples from the lower chamber were collected and assayed for radioactivity.
  
  
  RESULTS
  Glucose absorption increased with an increase in the level of differentiation and was associated with an increase in the protein expression level of glucose transporters. Leptin reduced glucose absorption only by day 16 after confluence, the time at which apical leptin receptors started appearing. This inhibitory effect became higher the longer the post confluence period, and was prominent on day 23. The hormone effect was found to be mediated via a decrease in the number of glucose transporters (SGLT1 and GLUT2) and a decrease in the activity of the Na+/K+ ATPase which was assayed by measuring the amount of inorganic phosphate liberated in presence and absence of enzyme activators.
  
  
  CONCLUSIONS
  It was concluded that by day 23 post confluence, Caco-2 cells are differentiated and are appropriate to use as a model for intestinal transport studies.
authors: Department of Biology, Faculty of Arts &amp; Sciences, American University of Beirut, Beirut, Lebanon.
authors: Ola
authors: O
authors: El-Zein
authors: Julnar
authors: J
authors: Usta
authors: Sawsan Ibrahim
authors: SI
authors: Kreydiyyeh
mesh_terms: D018938:Caco-2 Cells; D002454:Cell Differentiation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D005947:Glucose / Q000378:metabolism*; D051273:Glucose Transporter Type 2 / Q000378:metabolism*; D006801:Humans; D007408:Intestinal Absorption; D020738:Leptin / Q000494:pharmacology*; D008954:Models, Biological; D051269:Sodium-Glucose Transporter 1 / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D051273:Glucose Transporter Type 2; D020738:Leptin; C495680:SLC2A2 protein, human; C495674:SLC5A1 protein, human; D051269:Sodium-Glucose Transporter 1; D000254:Sodium-Potassium-Exchanging ATPase; D005947:Glucose