title: Nrf2 signalling promotes ex vivo tubular epithelial cell survival and regeneration via murine double minute (MDM)-2.
abstract: BACKGROUND
  Tubular repair upon injury involves regeneration from either surviving tubular epithelial cells or from their surviving local progenitor cells; hence, compound screening with cell lines may be inadequate. Here, we demonstrate that the renal cell isolation procedure and subsequent outgrowth of tubular cells can mimic the renal injury phase and tubular cell regeneration from whichever surviving renal cells.
  
  
  METHODS
  We set up assays to systematically screen and identify mediators of tubular survival and repair.
  
  
  RESULTS
  Forty-eight hours after plating total kidney isolates from C57BL/6 mice, 69% of cells survived when prepared from 2-week-old pups, but only 4% of cells from 8-week-old mice, respectively. This poor survival was not modulated by co-incubation with any of 24 cytokines and growth factors, except for the Nrf2 agonist sulforaphane. In addition, only sulforaphane enhanced the regenerative outgrowth of tubular epithelial cells from the mixed population. Furthermore, sulforaphane enhanced wound closure upon scratching tubular epithelial cell monolayers in a dose-dependent manner. This process was associated with the induction of the tested Nrf2 target genes HO-1, NQO1 and murine-double minute 2 (MDM2). MDM2 blockade with nutlin-3a completely blocked the protective effects of sulforaphane on renal cell survival, outgrowth and wound closure.
  
  
  CONCLUSIONS
  Together, renal cell isolation is a model of acute kidney injury (AKI). Primary tubular epithelial cell outgrowth represents a model of tubular regeneration. Nrf2 activation can enhance renal cell survival and tubular repair by inducing the cell cycle regulator MDM2.
authors.affiliation: Renal Division, Medizinische Klinik und Poliklinik IV, Ludwig Maximilian University of Munich, Munich, Germany.
authors.forename: Jan H
authors.initials: JH
authors.lastname: Hagemann
authors.forename: Dana
authors.initials: D
authors.lastname: Thomasova
authors.forename: Shrikant R
authors.initials: SR
authors.lastname: Mulay
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Anders
mesh_terms: D058186:Acute Kidney Injury / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology; D015153:Blotting, Western; D002470:Cell Survival; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D005434:Flow Cytometry; D017879:Isothiocyanates / Q000494:pharmacology; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D051267:NF-E2-Related Factor 2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012038:Regeneration / Q000187:drug effects / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013454:Sulfoxides; D014945:Wound Healing / Q000187:drug effects
chemical_list: D016588:Anticarcinogenic Agents; D017879:Isothiocyanates; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D012333:RNA, Messenger; D013454:Sulfoxides; C497207:Mdm2 protein, mouse; D051736:Proto-Oncogene Proteins c-mdm2; C016766:sulforaphane
keywords: acute kidney injury; oxidative stress; progenitor cells; regeneration; repair; tubular atrophy