Glucose and galactose regulate intestinal absorption of cholesterol

Biochem Biophys Res Commun. 2003 Oct 17;310(2):446-51. doi: 10.1016/j.bbrc.2003.08.150.

Abstract

A dose-dependent increase in cholesterol absorption was induced by glucose addition (0-75 mM) to the apical medium of TC7 cells, a well-characterized clone of Caco-2. The uptake into the cells and the secretion rate to the basolateral space were both enhanced by glucose and galactose. This up-regulation was suppressed by SGLT1 inhibition but not by GLUT2 inhibition. Cholesterol cell uptake was significantly decreased by PMA and increased by chelerythrine, with more pronounced changes in the presence of hexoses. Thus, the involvement of a protein kinase C signalling pathway was evidenced in the regulation processes of intestinal cholesterol absorption. In the presence of antibodies directed to hSR-BI cholesterol absorption was reduced by 40% and glucose or galactose no longer enhanced it. We suggest that glucose or galactose, through an interaction with SGLT1, activates a protein kinase C pathway that regulates the activity of one of the intestinal cholesterol transporters, namely hSR-BI.

MeSH terms

  • Biological Transport / drug effects
  • CD36 Antigens / physiology
  • Caco-2 Cells
  • Cholesterol / metabolism*
  • Dose-Response Relationship, Drug
  • Galactose / pharmacology*
  • Glucose / pharmacology*
  • Humans
  • Intestinal Absorption
  • Membrane Transport Proteins / physiology
  • Protein Kinase C / metabolism
  • Receptors, Immunologic*
  • Receptors, Lipoprotein / physiology
  • Receptors, Scavenger

Substances

  • CD36 Antigens
  • Membrane Transport Proteins
  • Receptors, Immunologic
  • Receptors, Lipoprotein
  • Receptors, Scavenger
  • Cholesterol
  • Protein Kinase C
  • Glucose
  • Galactose