Epidermal growth factor regulates fatty acid uptake and metabolism in Caco-2 cells

Am J Physiol. 1999 Mar;276(3):G606-12. doi: 10.1152/ajpgi.1999.276.3.G606.

Abstract

Epidermal growth factor (EGF) has been reported to stimulate carbohydrate, amino acid, and electrolyte transport in the small intestine, but its effects on lipid transport are poorly documented. This study aimed to investigate EGF effects on fatty acid uptake and esterification in a human enterocyte cell line (Caco-2). EGF inhibited cell uptake of [14C]palmitate and markedly reduced its incorporation into triglycerides. In contrast, the incorporation in phospholipids was enhanced. To elucidate the mechanisms involved, key steps of lipid synthesis were investigated. The amount of intestinal fatty acid-binding protein (I-FABP), which is thought to be important for fatty acid absorption, and the activity of diacylglycerol acyltransferase (DGAT), an enzyme at the branch point of diacylglycerol utilization, were reduced. EGF effects on DGAT and on palmitate esterification occurred at 2-10 ng/ml, whereas effects on I-FABP and palmitate uptake occurred only at 10 ng/ml. This suggests that EGF inhibited palmitate uptake by reducing the I-FABP level and shifted its utilization from triglycerides to phospholipids by inhibiting DGAT. This increase in phospholipid synthesis might play a role in the restoration of enterocyte absorption function after intestinal mucosa injury.

MeSH terms

  • Acyltransferases / metabolism
  • Caco-2 Cells
  • Carrier Proteins / metabolism
  • Coenzyme A Ligases / metabolism
  • Diacylglycerol O-Acyltransferase
  • Epidermal Growth Factor / pharmacology
  • Epidermal Growth Factor / physiology*
  • Fatty Acid-Binding Protein 7
  • Fatty Acid-Binding Proteins
  • Fatty Acids / metabolism*
  • Humans
  • Intestinal Mucosa / metabolism*
  • Intestines / pathology
  • Long-Chain-Fatty-Acid-CoA Ligase
  • Myelin P2 Protein / metabolism
  • Neoplasm Proteins*
  • Palmitic Acid / metabolism
  • Palmitic Acid / pharmacokinetics
  • Repressor Proteins*
  • Saccharomyces cerevisiae Proteins*
  • Tumor Suppressor Proteins*

Substances

  • Carrier Proteins
  • FABP7 protein, human
  • Fatty Acid-Binding Protein 7
  • Fatty Acid-Binding Proteins
  • Fatty Acids
  • Myelin P2 Protein
  • Neoplasm Proteins
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins
  • Tumor Suppressor Proteins
  • Palmitic Acid
  • Epidermal Growth Factor
  • Acyltransferases
  • DGAT1 protein, human
  • Diacylglycerol O-Acyltransferase
  • Coenzyme A Ligases
  • FAA2 protein, S cerevisiae
  • Long-Chain-Fatty-Acid-CoA Ligase