title: Increased progression to kidney fibrosis after erythropoietin is used as a treatment for acute kidney injury.
abstract: Treatment of renal ischemia-reperfusion (IR) injury with recombinant human erythropoietin (rhEPO) reduces acute kidney injury and improves function. We aimed to investigate whether progression to chronic kidney disease associated with acute injury was also reduced by rhEPO treatment, using in vivo and in vitro models. Rats were subjected to bilateral 40-min renal ischemia, and kidneys were studied at 4, 7, and 28 days postreperfusion for renal function, tubular injury and repair, inflammation, and fibrosis. Acute injury was modulated using rhEPO (1,000 or 5,000 IU/kg, intraperitoneally) at the time of reperfusion. Renal tubular epithelial cells or fibroblasts in culture were subjected to hypoxia or oxidative stress, with or without rhEPO (200 IU/ml), and fibrogenesis was studied. The results of the in vivo model confirmed functional and structural improvement with rhEPO at 4 days post-IR (P < 0.05). At 7 days post-IR, fibrosis and myofibroblast stimulation were increased with IR with and without rhEPO (P < 0.01). However, at 28 days post-IR, renal fibrosis and myofibroblast numbers were significantly greater with IR plus rhEPO (P < 0.01) compared with IR only. Mechanistically, rhEPO stimulated profibrotic transforming growth factor-β, oxidative stress (marker 8-hydroxy-deoxyguanosine), and phosphorylation of the signal transduction protein extracellular signal-regulated kinase. In vitro, rhEPO protected tubular epithelium from apoptosis but stimulated epithelial-to-mesenchymal transition and also protected and activated fibroblasts, particularly with oxidative stress. In summary, although rhEPO was protective of renal function and structure in acute kidney injury, the supraphysiological dose needed for renoprotection contributed to fibrogenesis and stimulated chronic kidney disease in the long term.
authors.affiliation: Centre for Kidney Disease Research, School of Medicine, Univ. of Queensland, Translational Research Institute, Kent St., Woolloongabba, Brisbane, Australia 4102.. g.gobe@uq.edu.au.
authors.forename: Glenda C
authors.initials: GC
authors.lastname: Gobe
authors.forename: Nigel C
authors.initials: NC
authors.lastname: Bennett
authors.forename: Malcolm
authors.initials: M
authors.lastname: West
authors.forename: Paul
authors.initials: P
authors.lastname: Colditz
authors.forename: Lindsay
authors.initials: L
authors.lastname: Brown
authors.forename: David A
authors.initials: DA
authors.lastname: Vesey
authors.forename: David W
authors.initials: DW
authors.lastname: Johnson
mesh_terms: D058186:Acute Kidney Injury / Q000188:drug therapy*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D018450:Disease Progression; D000068817:Epoetin Alfa; D004921:Erythropoietin / Q000627:therapeutic use*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005355:Fibrosis; D006801:Humans; D007668:Kidney / Q000473:pathology; D007674:Kidney Diseases / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000627:therapeutic use; D015427:Reperfusion Injury / Q000188:drug therapy / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D011994:Recombinant Proteins; D004921:Erythropoietin; D000068817:Epoetin Alfa; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: EPO; acute kidney injury; chronic kidney disease; erythropoietin; fibrosis; ischemia-reperfusion