title: Protective effect of erythropoietin against radiocontrast-induced renal tubular epithelial cell injury.
abstract: OBJECTIVE
  Recombinant human erythropoietin (rhEpo) has been shown to reduce tissue injury following ischemia-reperfusion. We examined whether rhEpo protects in vitro renal tubular epithelial cells against radiocontrast media-induced injury.
  
  
  METHODS
  LLC-PK1 renal tubular epithelial cells were exposed to non-ionic radiocontrast agent iohexol (low-osmolar) or iodixanol (iso-osmolar), with or without rhEpo (200 U/ml). Following a 6-hour exposure, cells were incubated for 24 h in radiocontrast-free culture medium. Cell viability was then assessed by the MTT assay. We also assessed cell apoptosis by the TUNEL assay, and activities of caspase-3, caspase-8, and caspase-9 were determined by a luminescence assay.
  
  
  RESULTS
  rhEpo improved viability of iohexol-treated LLC-PK1 cells by 27 +/- 6% (88.1 +/- 1.5 vs. 70.8 +/- 3.3%, p = 0.008). Similarly, rhEpo improved the viability of iodixanol-treated LLC-PK1 cells by 26 +/- 4% (82.5 +/- 2.1vs. 65.7 +/- 1.7%, p = 0.028). rhEpo also decreased apoptosis rates of iohexol-treated LLC-PK1 cells (6.4 +/- 0.9/1,000 cells vs. 14.8 +/- 2.4/1,000 cells, p = 0.028), and iodixanol-treated LLC-PK1 cells (8.0 +/- 1.2/1,000 cells vs. 13.5 +/- 1.9/1,000 cells, p = 0.028). In iohexol-treated LLC-PK1 cells, rhEpo attenuated activation of caspase-3 (p = 0.003), caspase-8 (p = 0.033) and caspase-9 (p = 0.055).
  
  
  CONCLUSIONS
  rhEpo attenuates in vitro renal tubular epithelial cell injury induced by low- and iso-osmolar radiocontrast media, possibly by reduction of caspases activation and apoptosis rates.
authors.affiliation: Department of Medicine, Division of Nephrology, Kidney and Dialysis Research Laboratory, Caritas St. Elizabeth's Medical Center, Boston, Mass. 02135, USA. Alexey.Kolyada@caritaschristi.org
authors.forename: Alexey Y
authors.initials: AY
authors.lastname: Kolyada
authors.forename: Orfeas
authors.initials: O
authors.lastname: Liangos
authors.forename: Nicolaos E
authors.initials: NE
authors.lastname: Madias
authors.forename: Bertrand L
authors.initials: BL
authors.lastname: Jaber
mesh_terms: D000818:Animals; D017209:Apoptosis; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival; D003287:Contrast Media / Q000009:adverse effects* / Q000494:pharmacology; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D004921:Erythropoietin / Q000627:therapeutic use*; D020287:In Situ Nick-End Labeling; D007472:Iohexol / Q000494:pharmacology; D007684:Kidney Tubules / Q000166:cytology* / Q000378:metabolism; D018374:LLC-PK1 Cells; D011994:Recombinant Proteins; D015427:Reperfusion Injury; D013552:Swine; D014283:Triiodobenzoic Acids / Q000494:pharmacology
chemical_list: D003287:Contrast Media; D011994:Recombinant Proteins; D014283:Triiodobenzoic Acids; D004921:Erythropoietin; D007472:Iohexol; D020169:Caspases; C044834:iodixanol