title: Oxygen-regulated expression of the erythropoietin gene in the human renal cell line REPC.
abstract: Erythropoietin (EPO), the key hormone in red blood cell renewal, is mainly produced in the adult kidney. Anemia and hypoxia substantially enhance EPO expression to increase erythropoiesis. Investigations of the cellular physiology of renal EPO production have been hampered by the lack of an adequate human cell line. In the present study, we present the human kidney cell line REPC (for renal Epo-producing cells), established from an explanted human kidney exhibiting EPO gene expression and release of the EPO protein in an oxygen-dependent manner. Hypoxic induction of EPO mRNA showed the typical transient increase and peak in expression after 36 hours under continuous conditions of hypoxia. Bioactive EPO protein accumulated in the culture supernatant. The induction of EPO gene expression in REPCs critically depended on the activation of hypoxia-inducible transcription factors (HIFs). SiRNA treatment revealed that the expression of EPO was largely dependent on the activation of the transcription factor complex HIF-2. In addition, hepatic nuclear factor 4α was shown to be critically involved in hypoxia-induced renal EPO expression. Using the human kidney cell line REPC, we provide for the first time a powerful tool with which to study the cellular and molecular regulation of renal EPO production.
authors.affiliation: Institut für Physiologie, Universität Duisburg-Essen, Essen, Germany.
authors.forename: Stilla
authors.initials: S
authors.lastname: Frede
authors.forename: Patricia
authors.initials: P
authors.lastname: Freitag
authors.forename: Luise
authors.initials: L
authors.lastname: Geuting
authors.forename: Rebecca
authors.initials: R
authors.lastname: Konietzny
authors.forename: Joachim
authors.initials: J
authors.lastname: Fandrey
mesh_terms: D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015687:Cell Hypoxia / Q000235:genetics; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D049308:Dioxygenases / Q000235:genetics; D004920:Erythropoiesis / Q000235:genetics / Q000502:physiology; D004921:Erythropoietin / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D011393:Procollagen-Proline Dioxygenase / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D015533:Transcriptional Activation; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D017931:DNA Primers; D049308:Dioxygenases; D004921:Erythropoietin; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases; D010100:Oxygen; D011393:Procollagen-Proline Dioxygenase; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000099162:Endothelial PAS Domain-Containing Protein 1; C554270:EPO protein, human; C497442:HIF1A protein, human; C490190:EGLN1 protein, human; C488894:EGLN3 protein, human