title: Extracellular metabolism-dependent uptake of lysolipids through cultured monolayer of differentiated Caco-2 cells.
abstract: Glycerophospholipids are known to be hydrolyzed in the intestinal lumen into free fatty acids and lysophospholipids that are then absorbed by the intestinal epithelial cells. A monolayer of enterocyte-differentiated Caco-2 cell is often used to assess the intestinal bioavailability of nutrients. In this study, we examined how differentiated Caco-2 cells process lysoglycerolipids such as lysophosphatidylcholine (LPC). Our findings were twofold. (1) Caco-2 cells secreted both a lysophospholipase A-like enzyme and a glycerophosphocholine-phosphodiesterase enzyme into the apical, but not basolateral, lumen, suggesting that food-derived LPC is converted to a free fatty acid, sn-glycerol-3-phosphate, and choline through two sequential enzymatic reactions in humans. The release of the latter enzyme was differentiation-dependent. (2) Fatty acid-releasing activities toward exogenous fluorescent LPC, lysophosphatidic acid and monoacylglycerol were shown to be higher on the apical membranes of Caco-2 cells than on the basolateral membranes. These results suggest that human intestinal epithelial cells metabolize lysoglycerolipids by two distinct mechanisms involving secreted or apical-selective expression of metabolic enzymes.
authors.affiliation: Department of Pharmaceutical Health Chemistry, Institute of Health Biosciences, University of Tokushima Graduate School, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Inaba
authors.forename: Kaeko
authors.initials: K
authors.lastname: Murota
authors.forename: Miki
authors.initials: M
authors.lastname: Nikawadori
authors.forename: Erika
authors.initials: E
authors.lastname: Kishino
authors.forename: Risa
authors.initials: R
authors.lastname: Matusda
authors.forename: Mika
authors.initials: M
authors.lastname: Takagi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohkubo
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Tanaka
authors.forename: Junji
authors.initials: J
authors.lastname: Terao
authors.forename: Akira
authors.initials: A
authors.lastname: Tokumura
mesh_terms: D018938:Caco-2 Cells; D002794:Choline / Q000378:metabolism*; D005994:Glycerophosphates / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism / Q000502:physiology*; D008244:Lysophosphatidylcholines / Q000378:metabolism*; D008245:Lysophospholipase / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*
chemical_list: D005994:Glycerophosphates; D008244:Lysophosphatidylcholines; D008245:Lysophospholipase; D010727:Phosphoric Diester Hydrolases; C020677:glycerophosphocholine phosphodiesterase; D002794:Choline
keywords: Caco-2 cell; GPC phosphodiesterase; Lysophosphatidic acid; Lysophosphatidylcholine; Lysophospholipase; Monoacylglycerol