title: Novel conditionally immortalized human proximal tubule cell line expressing functional influx and efflux transporters.
abstract: Reabsorption of filtered solutes from the glomerular filtrate and excretion of waste products and xenobiotics are the main functions of the renal proximal tubular (PT) epithelium. A human PT cell line expressing a range of functional transporters would help to augment current knowledge in renal physiology and pharmacology. We have established and characterized a conditionally immortalized PT epithelial cell line (ciPTEC) obtained by transfecting and subcloning cells exfoliated in the urine of a healthy volunteer. The PT origin of this line has been confirmed morphologically and by the expression of aminopeptidase N, zona occludens 1, aquaporin 1, dipeptidyl peptidase IV and multidrug resistance protein 4 together with alkaline phosphatase activity. ciPTEC assembles in a tight monolayer with limited diffusion of inulin-fluorescein-isothiocyanate. Concentration and time-dependent reabsorption of albumin via endocytosis has been demonstrated, together with sodium-dependent phosphate uptake. The expression and activity of apical efflux transporter p-glycoprotein and of baso-lateral influx transporter organic cation transporter 2 have been shown in ciPTEC. This established human ciPTEC expressing multiple endogenous organic ion transporters mimicking renal reabsorption and excretion represents a powerful tool for future in vitro transport studies in pharmacology and physiology.
authors.affiliation: Laboratory of Pediatrics and Neurology (656), Radboud University Nijmegen Medical Center, P.O. 9101, 6500 HB, Nijmegen, The Netherlands. m.wilmer@cukz.umcn.nl
authors.forename: Martijn J
authors.initials: MJ
authors.lastname: Wilmer
authors.forename: Moin A
authors.initials: MA
authors.lastname: Saleem
authors.forename: Rosalinde
authors.initials: R
authors.lastname: Masereeuw
authors.forename: Lan
authors.initials: L
authors.lastname: Ni
authors.forename: Thea J
authors.initials: TJ
authors.lastname: van der Velden
authors.forename: Frans G
authors.initials: FG
authors.lastname: Russel
authors.forename: Peter W
authors.initials: PW
authors.lastname: Mathieson
authors.forename: Leo A
authors.initials: LA
authors.lastname: Monnens
authors.forename: Lambertus P
authors.initials: LP
authors.lastname: van den Heuvel
authors.forename: Elena N
authors.initials: EN
authors.lastname: Levtchenko
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000378:metabolism; D051398:Aquaporin 1 / Q000378:metabolism; D018826:CD13 Antigens / Q000378:metabolism; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000473:pathology*; D008565:Membrane Proteins / Q000378:metabolism; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism; D027701:Organic Cation Transport Proteins / Q000378:metabolism*; D000075102:Organic Cation Transporter 2; D010750:Phosphoproteins / Q000378:metabolism; D062826:Zonula Occludens-1 Protein
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000469:Alkaline Phosphatase; D051398:Aquaporin 1; D018826:CD13 Antigens; D018819:Dipeptidyl Peptidase 4; D008565:Membrane Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D027701:Organic Cation Transport Proteins; D000075102:Organic Cation Transporter 2; D010750:Phosphoproteins; D062826:Zonula Occludens-1 Protein; C073492:ABCC4 protein, human; C491013:SLC22A2 protein, human; C569042:TJP1 protein, human