title: Cellular differentiation and I-FABP protein expression modulate fatty acid uptake and diffusion.
abstract: The effect of cellular differentiation on fatty acid uptake and intracellular diffusion was examined in transfected pluripotent mouse embryonic stem (ES) cells stably expressing intestinal fatty acid binding protein (I-FABP). Control ES cells, whether differentiated or undifferentiated, did not express I-FABP. The initial rate and maximal uptake of the fluorescent fatty acid, 12-(N-methyl)-N-[(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-octadec anoic acid (NBD-stearic acid), was measured in single cells by kinetic digital fluorescence imaging. I-FABP expression in undifferentiated ES cells increased the initial rate and maximal uptake of NBD-stearic acid 1.7- and 1.6-fold, respectively, as well as increased its effective intracellular diffusion constant (Deff) 1.8-fold as measured by the fluorescence recovery after photobleaching technique. In contrast, ES cell differentiation decreased I-FABP expression up to 3-fold and decreased the NBD-stearic acid initial rate of uptake, maximal uptake, and Deff by 10-, 4.7-, and 2-fold, respectively. There were no significant differences in these parameters between the differentiated control and differentiated I-FABP-expressing ES cell lines. In summary, differentiation and expression of I-FABP oppositely modulated NBD-stearic acid uptake parameters and intracellular diffusion in ES cells.
authors.affiliation: Department of Physiology and Pharmacology, Texas Veterinary Medical Center, Texas A&M University, College Station 77843-4466, USA.
authors.forename: B P
authors.initials: BP
authors.lastname: Atshaves
authors.forename: W B
authors.initials: WB
authors.lastname: Foxworth
authors.forename: A
authors.initials: A
authors.lastname: Frolov
authors.forename: J B
authors.initials: JB
authors.lastname: Roths
authors.forename: A B
authors.initials: AB
authors.lastname: Kier
authors.forename: B K
authors.initials: BK
authors.lastname: Oetama
authors.forename: J A
authors.initials: JA
authors.lastname: Piedrahita
authors.forename: F
authors.initials: F
authors.lastname: Schroeder
mesh_terms: D009327:4-Chloro-7-nitrobenzofurazan / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D002454:Cell Differentiation; D002478:Cells, Cultured; D002999:Clone Cells / Q000378:metabolism; D004058:Diffusion; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism*; D007202:Indicators and Reagents / Q000493:pharmacokinetics; D051379:Mice; D018996:Myelin P2 Protein / Q000096:biosynthesis* / Q000235:genetics; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D013228:Stearates / Q000493:pharmacokinetics; D013234:Stem Cells / Q000378:metabolism; D014162:Transfection
chemical_list: D002352:Carrier Proteins; C082667:Fabp5 protein, mouse; C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D007202:Indicators and Reagents; D018996:Myelin P2 Protein; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D013228:Stearates; C060027:12-N-methyl-7-nitrobenzo-2-oxa-1,3-diazolamino stearate; D009327:4-Chloro-7-nitrobenzofurazan