title: Regional levels of drug transporters along the human intestinal tract: co-expression of ABC and SLC transporters and comparison with Caco-2 cells.
abstract: A vast number of drugs are subjected to active or facilitated transport and multiple transport mechanism may contribute to the net flux during drug absorption. The main objective of this study was to quantify the regional mRNA expression and determine the co-expression of drug transporters from the ABC (Pgp, BCRP, MRP2, MRP3) and SLC (PEPT1, MCT1, OATPB, OCTN2, OCT1) families along the human intestine (duodenum, jejunum, ileum, and colon). A second objective was to compare the transporter expression between the different intestinal regions and Caco-2 cells. Eight out of nine of the investigated transporters exhibited significant regional differences in expression. OATPB was the only transporter that did not show a region-dependency in the expression along the human intestinal canal. The expression of Pgp, BCRP, OCTN2 and MCT1 differed along the small intestine, but the expression differences were greater than five-fold only for Pgp. The rank order of transcript prevalence was identical in the ileum and the jejunum. Between the ileum and colon, seven transcripts were differentially expressed, and MCT1, OCTN2 and MRP3 were expressed at higher levels in the colon than in the small intestine. The expression of transporters in Caco-2 was closest to the expression pattern in the small intestine, although the expression of OATPB, BCRP and MRP2 differed more than five-fold between the Caco-2 cells and ileum. In conclusion, this study provides quantitative data on the expression of transporters from the ABC and SLC families along the human intestine, which can be useful in the interpretation of clinical studies where more than one intestinal transporter contribute to the net transport and in the computer modelling of drug absorption.
authors.affiliation: Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Gunilla
authors.initials: G
authors.lastname: Englund
authors.forename: Fredrik
authors.initials: F
authors.lastname: Rorsman
authors.forename: Anders
authors.initials: A
authors.lastname: Rönnblom
authors.forename: Urban
authors.initials: U
authors.lastname: Karlbom
authors.forename: Lucia
authors.initials: L
authors.lastname: Lazorova
authors.forename: Johan
authors.initials: J
authors.lastname: Gråsjö
authors.forename: Andreas
authors.initials: A
authors.lastname: Kindmark
authors.forename: Per
authors.initials: P
authors.lastname: Artursson
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D001692:Biological Transport; D018938:Caco-2 Cells; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D027501:Monocarboxylic Acid Transporters / Q000235:genetics*; D050811:Octamer Transcription Factor-1 / Q000235:genetics*; D027701:Organic Cation Transport Proteins / Q000235:genetics*; D000074011:Peptide Transporter 1; D012333:RNA, Messenger / Q000032:analysis; D000074058:Solute Carrier Family 22 Member 5; D027981:Symporters / Q000235:genetics*; D000099233:Monocarboxylate Transport Protein 1
chemical_list: D018528:ATP-Binding Cassette Transporters; D027501:Monocarboxylic Acid Transporters; D050811:Octamer Transcription Factor-1; D027701:Organic Cation Transport Proteins; D000074011:Peptide Transporter 1; D012333:RNA, Messenger; D000074058:Solute Carrier Family 22 Member 5; D027981:Symporters; D000099233:Monocarboxylate Transport Protein 1; C494165:POU2F1 protein, human; C082186:SLC15A1 protein, human; C492020:SLC22A5 protein, human