title: Gene expression analysis and urinary biomarker assays reveal activation of tubulointerstitial injury pathways in a rodent model of chronic proteinuria (Doxorubicin nephropathy).
abstract: BACKGROUND
  Tubular atrophy and interstitial fibrosis are well-recognized sequelae of chronic proteinuria; however, little is known regarding the molecular pathways activated within tubulointerstitium in chronic proteinuric nephropathies.
  
  
  METHODS
  To investigate the molecular mechanisms of proteinuria-associated tubulointerstitial (TI) disease, doxorubicin nephropathy was induced in rats. Progression of disease was monitored with weekly urinary biomarker assays. Because histopathology revealed multifocal TI injury, immunodirected laser capture microdissection was used to identify and isolate injured proximal tubules, as indicated by kidney injury molecule-1 immunolabeling. Adjacent interstitial cells were harvested separately. Gene expression microarray, manual annotation of gene lists, and Gene Set Enrichment Analysis were performed. A subset of the regulated transcripts was validated by quantitative PCR and immunohistochemistry.
  
  
  RESULTS
  Severe proteinuria preceded tubular injury biomarkers by 1 week. Histology revealed multifocal, mild TI damage at 3 weeks, which progressed in severity at 5 weeks. Affymetrix microarray analysis revealed tissue-specific regulation of gene expression. Manual annotation of gene lists, gene set enrichment analysis, and urinary biomarker assays revealed similarities to pathways activated in direct TI injuries. This suggests commonalities amongst the molecular mechanisms of TI injury secondary to proteinuria, ischemia-reperfusion, and nephrotoxicity. © 2013 S. Karger AG, Basel.
authors.affiliation: Safety Assessment, GlaxoSmithKline, Research Triangle Park, N.C., USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Cianciolo
authors.forename: Lawrence
authors.initials: L
authors.lastname: Yoon
authors.forename: David
authors.initials: D
authors.lastname: Krull
authors.forename: Alan
authors.initials: A
authors.lastname: Stokes
authors.forename: Alex
authors.initials: A
authors.lastname: Rodriguez
authors.forename: Holly
authors.initials: H
authors.lastname: Jordan
authors.forename: David
authors.initials: D
authors.lastname: Cooper
authors.forename: James G
authors.initials: JG
authors.lastname: Falls
authors.forename: John
authors.initials: J
authors.lastname: Cullen
authors.forename: Carie
authors.initials: C
authors.lastname: Kimbrough
authors.forename: Brian
authors.initials: B
authors.lastname: Berridge
mesh_terms: D000419:Albuminuria / Q000235:genetics / Q000652:urine; D000818:Animals; D015415:Biomarkers / Q000652:urine*; D015815:Cell Adhesion Molecules / Q000652:urine; D002908:Chronic Disease; D004195:Disease Models, Animal; D018450:Disease Progression; D004317:Doxorubicin; D007150:Immunohistochemistry; D007674:Kidney Diseases / Q000139:chemically induced / Q000235:genetics / Q000652:urine; D007687:Kidney Tubules, Proximal / Q000378:metabolism* / Q000473:pathology; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D053495:Osteopontin / Q000652:urine; D011507:Proteinuria / Q000235:genetics* / Q000652:urine*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics*; D013997:Time Factors; D059467:Transcriptome
chemical_list: D015415:Biomarkers; D015815:Cell Adhesion Molecules; D004317:Doxorubicin; D000071068:Lipocalin-2; D054834:Lipocalins; D053495:Osteopontin; C110936:Havcr1 protein, rat; C097278:Lcn2 protein, rat