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This Article Full Text Full Text (PDF) All Versions of this Article: 295/5/F1365    most recent 90405.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Wieser, M. Articles by Grillari-Voglauer, R. Search for Related Content PubMed PubMed Citation Articles by Wieser, M. Articles by Grillari-Voglauer, R.

hTERT alone immortalizes epithelial cells of renal proximal tubules without changing their functional characteristics

¹Aging and Immortalization Research, Institute of Applied Microbiology, Department of Biotechnology, BOKU-University of Natural Resources and Applied Life Sciences, Vienna; ²Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck; ³Department of Pathology, Medical University of Vienna and ⁴Tumor Biology, Children's Cancer Research Institute, St. Anna Children's Hospital, Vienna; and ⁵Urology, Landesklinikum Thermenregion Baden, Baden, Austria

Submitted 9 July 2008 ; accepted in final form 14 August 2008

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 β-galactosidase, and accumulation of -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.

renal proximal tubule cell; renal cell biology; immortalization