title: Retrograde cholesterol transport in the human Caco-2/TC7 cell line: a model to study trans-intestinal cholesterol excretion in atherogenic and diabetic dyslipidemia.
abstract: OBJECTIVE
  The dyslipidemia associated with type 2 diabetes is a major risk factor for the development of atherosclerosis. Trans-intestinal cholesterol excretion (TICE) has recently been shown to contribute, together with the classical hepatobiliary route, to fecal cholesterol excretion and cholesterol homeostasis. The aim of this study was to develop an in vitro cell model to investigate enterocyte-related processes of TICE.
  
  
  METHODS
  Differentiated Caco-2/TC7 cells were grown on transwells and incubated basolaterally (blood side) with human plasma and apically (luminal side) with lipid micelles. Radioactive and fluorescent cholesterol tracers were used to investigate cholesterol uptake at the basolateral membrane, intracellular distribution and apical excretion.
  
  
  RESULTS
  Our results show that cholesterol is taken up at the basolateral membrane, accumulates intracellularly as lipid droplets and undergoes a cholesterol acceptor-facilitated and progressive excretion through the apical membrane of enterocytes. The overall process is abolished at 4 °C, suggesting a biologically active phenomenon. Moreover, this trans-enterocytic retrograde cholesterol transport displays some TICE features like modulation by PCSK9 and an ABCB1 inhibitor. Finally, we highlight the involvement of microtubules in the transport of plasma cholesterol from basolateral to apical pole of enterocytes.
  
  
  CONCLUSIONS
  The human Caco-2/TC7 cell line appears a good in vitro model to investigate the enterocytic molecular mechanisms of TICE, which may help to identify intestinal molecular targets to enhance reverse cholesterol transport and fight against dyslipidemia.
authors: Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France.
authors: Camille
authors: C
authors: Dugardin
authors: Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France.
authors: Olivier
authors: O
authors: Briand
authors: Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France.
authors: Véronique
authors: V
authors: Touche
authors: University Medical Center Groningen, Department of Pediatrics, University of Groningen, Groningen, The Netherlands.
authors: Marleen
authors: M
authors: Schonewille
authors: INSERM, UMR 1087, CNRS UMR 6291, 44000, Nantes, France.
authors: François
authors: F
authors: Moreau
authors: INSERM, UMR 1087, CNRS UMR 6291, 44000, Nantes, France.
authors: Cédric
authors: C
authors: Le May
authors: University Medical Center Groningen, Department of Pediatrics, University of Groningen, Groningen, The Netherlands.|Academic Medical Center, Amsterdam, The Netherlands.
authors: Albert K
authors: AK
authors: Groen
authors: Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France. bart.staels@pasteur-lille.fr.
authors: Bart
authors: http://orcid.org/0000-0003-2979-0395
authors: B
authors: Staels
authors: Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France.
authors: Sophie
authors: S
authors: Lestavel
mesh_terms: D050197:Atherosclerosis / Q000150:complications*; D018938:Caco-2 Cells; D002784:Cholesterol / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D050171:Dyslipidemias / Q000209:etiology / Q000378:metabolism*; D020895:Enterocytes / Q000378:metabolism*; D005089:Exocytosis; D006801:Humans
chemical_list: D002784:Cholesterol
keywords: Efflux; Intracellular cholesterol trafficking; Lipid; Microtubules