title: hTERT alone immortalizes epithelial cells of renal proximal tubules without changing their functional characteristics.
abstract: Telomere-dependent replicative senescence is one of the mechanisms that limit the number of population doublings of normal human cells. By overexpression of telomerase, cells of various origins have been successfully immortalized without changing the phenotype. While a limited number of telomerase-immortalized cells of epithelial origin are available, none of renal origin has been reported so far. Here we have established simple and safe conditions that allow serial passaging of renal proximal tubule epithelial cells (RPTECs) until entry into telomere-dependent replicative senescence. As reported for other cells, senescence of RPTECs is characterized by arrest in G1 phase, shortened telomeres, staining for senescence-associated beta-galactosidase, and accumulation of gamma-H2AX foci. Furthermore, ectopic expression of the catalytic subunit of telomerase (TERT) was sufficient to immortalize these cells. Characterization of immortalized RPTEC/TERT1 cells shows characteristic morphological and functional properties like formation of tight junctions and domes, expression of aminopeptidase N, cAMP induction by parathyroid hormone, sodium-dependent phosphate uptake, and the megalin/cubilin transport system. No genomic instability within up to 90 population doublings has been observed. Therefore, these cells are proposed as a valuable model system not only for cell biology but also for toxicology, drug screening, biogerontology, as well as tissue engineering approaches.
authors: Aging and Immortalization Research, Institute of Applied Microbiology, Department of Biotechnology, BOKU-University of Natural Resources and Applied Sciences, Vienna, Austria.
authors: Matthias
authors: M
authors: Wieser
authors: Guido
authors: G
authors: Stadler
authors: Paul
authors: P
authors: Jennings
authors: Berthold
authors: B
authors: Streubel
authors: Walter
authors: W
authors: Pfaller
authors: Peter
authors: P
authors: Ambros
authors: Claus
authors: C
authors: Riedl
authors: Hermann
authors: H
authors: Katinger
authors: Johannes
authors: J
authors: Grillari
authors: Regina
authors: R
authors: Grillari-Voglauer
mesh_terms: D018826:CD13 Antigens / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology; D002461:Cell Line, Transformed; D049109:Cell Proliferation; D016922:Cellular Senescence / Q000502:physiology; D002923:Cilia / Q000648:ultrastructure; D000242:Cyclic AMP / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D006657:Histones / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007687:Kidney Tubules, Proximal / Q000166:cytology; D008565:Membrane Proteins / Q000378:metabolism; D008854:Microscopy, Electron; D008871:Microvilli / Q000648:ultrastructure; D062793:Occludin; D010281:Parathyroid Hormone / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D050608:Sodium-Phosphate Cotransporter Proteins / Q000378:metabolism; D019098:Telomerase / Q000235:genetics* / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism / Q000648:ultrastructure; D014162:Transfection; D001616:beta-Galactosidase / Q000378:metabolism; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D015820:Cadherins; C468783:H2AX protein, human; D006657:Histones; D008565:Membrane Proteins; C568985:OCLN protein, human; D062793:Occludin; D010281:Parathyroid Hormone; D011956:Receptors, Cell Surface; D050608:Sodium-Phosphate Cotransporter Proteins; D000242:Cyclic AMP; D005723:gamma-Glutamyltransferase; D019098:Telomerase; D001616:beta-Galactosidase; D018826:CD13 Antigens