title: Intestinal scavenger receptors are involved in vitamin K1 absorption.
abstract: Vitamin K1 (phylloquinone) intestinal absorption is thought to be mediated by a carrier protein that still remains to be identified. Apical transport of vitamin K1 was examined using Caco-2 TC-7 cell monolayers as a model of human intestinal epithelium and in transfected HEK cells. Phylloquinone uptake was then measured ex vivo using mouse intestinal explants. Finally, vitamin K1 absorption was compared between wild-type mice and mice overexpressing scavenger receptor class B type I (SR-BI) in the intestine and mice deficient in cluster determinant 36 (CD36). Phylloquinone uptake by Caco-2 cells was saturable and was significantly impaired by co-incubation with α-tocopherol (and vice versa). Anti-human SR-BI antibodies and BLT1 (a chemical inhibitor of lipid transport via SR-BI) blocked up to 85% of vitamin K1 uptake. BLT1 also decreased phylloquinone apical efflux by ∼80%. Transfection of HEK cells with SR-BI and CD36 significantly enhanced vitamin K1 uptake, which was subsequently decreased by the addition of BLT1 or sulfo-N-succinimidyl oleate (CD36 inhibitor), respectively. Similar results were obtained in mouse intestinal explants. In vivo, the phylloquinone postprandial response was significantly higher, and the proximal intestine mucosa phylloquinone content 4 h after gavage was increased in mice overexpressing SR-BI compared with controls. Phylloquinone postprandial response was also significantly increased in CD36-deficient mice compared with wild-type mice, but their vitamin K1 intestinal content remained unchanged. Overall, the present data demonstrate for the first time that intestinal scavenger receptors participate in the absorption of dietary phylloquinone.
authors.affiliation: INRA, UMR 1260 "Nutrition, Obesity, and Risk of Thrombosis," F-13385 Marseille, France,; INSERM, UMR 1062, F-13385 Marseille, France,; Aix-Marseille Université, F-13385 Marseille, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Goncalves
authors.affiliation: INRA, UMR 1260 "Nutrition, Obesity, and Risk of Thrombosis," F-13385 Marseille, France,; INSERM, UMR 1062, F-13385 Marseille, France,; Aix-Marseille Université, F-13385 Marseille, France.
authors.forename: Marielle
authors.initials: M
authors.lastname: Margier
authors.affiliation: INRA, UMR 1260 "Nutrition, Obesity, and Risk of Thrombosis," F-13385 Marseille, France,; INSERM, UMR 1062, F-13385 Marseille, France,; Aix-Marseille Université, F-13385 Marseille, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Roi
authors.affiliation: INSERM/UPS U1048, Hôpital Rangueil, F-31432 Toulouse, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Collet
authors.affiliation: UMR 866 INSERM/AgroSup Dijon/Université de Bourgogne "Physiologie de la Nutrition," F-21000 Dijon, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Niot
authors.affiliation: INRA, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, Site Agroparc, F-84000 Avignon, France, and; Université d'Avignon et des Pays de Vaucluse, F-84000 Avignon, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Goupy
authors.affiliation: INRA, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, Site Agroparc, F-84000 Avignon, France, and; Université d'Avignon et des Pays de Vaucluse, F-84000 Avignon, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Caris-Veyrat
authors.affiliation: INRA, UMR 1260 "Nutrition, Obesity, and Risk of Thrombosis," F-13385 Marseille, France,; INSERM, UMR 1062, F-13385 Marseille, France,; Aix-Marseille Université, F-13385 Marseille, France,. Electronic address: Emmanuelle.Reboul@univ-amu.fr.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Reboul
mesh_terms: D000818:Animals; D018955:CD36 Antigens / Q000235:genetics / Q000378:metabolism; D018938:Caco-2 Cells; D002462:Cell Membrane; D002784:Cholesterol / Q000378:metabolism; D020895:Enterocytes / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007408:Intestinal Absorption; D051379:Mice; D008823:Micelles; D019518:Postprandial Period; D051122:Scavenger Receptors, Class B / Q000502:physiology*; D014810:Vitamin E / Q000378:metabolism; D010837:Vitamin K 1 / Q000378:metabolism*
chemical_list: D018955:CD36 Antigens; D008823:Micelles; C495124:SCARB1 protein, human; D051122:Scavenger Receptors, Class B; D014810:Vitamin E; D010837:Vitamin K 1; D002784:Cholesterol
keywords: Cell Culture; Intestinal Absorption; Intestine; Scavenger Receptor; Transgenic Mice; Vitamin K