Modulation of intestinal and liver fatty acid-binding proteins in Caco-2 cells by lipids, hormones and cytokines.
Intestinal and liver fatty acid binding proteins (I- and L-FABP) are thought to play a role in enterocyte fatty acid (FA) trafficking. Their modulation by cell differentiation and various potential effectors was investigated in the human Caco-2 cell line. With the acquisition of enterocytic features, Caco-2 cells seeded on plastic progressively increased L-FABP quantities, whereas I-FABP was not detectable even very late in the maturation process. On permeable filters that improved differentiation markers (sucrase, alkaline phosphatase, transepithelial resistance), Caco-2 cells furthered their L-FABP content and expressed I-FABP. Western blot analysis showed a significant increase in I- and L-FABP expression following an 8-hour incubation period with butyric acid, oleic acid, and phosphatidylcholine. However, in all cases, I-FABP levels were higher than L-FABP concentrations regardless of the lipid substrates added. Similarly, hydrocortisone and insulin enhanced the cellular content of I- and L-FABP whereas leptin triggered I-FABP expression only after an 8-hour incubation. Finally, tumor necrosis factor-alpha was more effective in increasing the cytosolic amount of I-FABP levels. In conclusion, our data demonstrate that I-FABP expression is limited to fully differentiated Caco-2 cells and can be more easily regulated than L-FABP by lipids, hormones, and cytokines.
Dubé
N
N
Centre de Recherche, Hôpital Sainte-Justine and Department of Nutrition, Université de Montréal, Montréal, Quebec, Canada H3T 1C5.
Delvin
E
E
Yotov
W
W
Garofalo
C
C
Bendayan
M
M
Veerkamp
J H
JH
Levy
E
E
D018938:Caco-2 Cells / Q000166:cytology / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D016207:Cytokines / Q000378:metabolism*; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism*; D006728:Hormones / Q000378:metabolism*; D006801:Humans; D020738:Leptin / Q000378:metabolism; D009363:Neoplasm Proteins; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D025521:Tumor Suppressor Proteins
D002352:Carrier Proteins; D016207:Cytokines; C493319:FABP1 protein, human; C107608:FABP7 protein, human; C493320:Fabp1 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D006728:Hormones; D020738:Leptin; D009363:Neoplasm Proteins; D014409:Tumor Necrosis Factor-alpha; D025521:Tumor Suppressor Proteins