title: Quantitative gene expression of TGF-beta1, IL-10, TNF-alpha and Fas Ligand in renal cortex and medulla.
abstract: BACKGROUND
  Inflammatory, fibrogenic or apoptotic processes in the kidney are regulated by intra- and intercellular mediators. Intrarenal upregulation of genes may precede structural changes by days and can be examined in extremely small amounts of tissue. With the advent of new quantitative PCR methods results of gene expression are available within few hours after kidney biopsies.
  
  
  METHODS
  In order to establish reference values for intrarenal gene expression of TGF-beta1, IL-10, TNF-alpha and Fas Ligand in renal cortex and medulla, we analysed 28 histologically normal kidney samples available after tumour nephrectomy by quantitative real-time PCR. After reverse transcription of isolated RNA, cDNA aliquots were quantified for target genes using the threshold cycle (C(t)) method normalized for the house keeping gene GAPDH.
  
  
  RESULTS
  Expression of target genes was lower in cortex as compared to medulla, but the differences were only significant for IL-10 (P=0.0125). TGF-beta1 was found with the highest gene expression about five PCR-cycles (delta C(t)) after GAPDH with markedly lower results for TNF-alpha (delta C(t) approximately 9), IL-10 (approximately 12) and Fas Ligand (approximately 14).
  
  
  CONCLUSIONS
  These results are the first reported reference values for human intrarenal gene expression which should facilitate interpretation of data from native or transplant kidneys in future studies.
authors.affiliation: Department of Paediatric Nephrology and Metabolic Diseases, Children's Hospital, Hannover Medical School, D-30623 Hannover, Germany. cschnak@gwdg.de
authors.forename: Christian
authors.initials: C
authors.lastname: von Schnakenburg
authors.forename: Juergen
authors.initials: J
authors.lastname: Strehlau
authors.forename: Jochen H H
authors.initials: JH
authors.lastname: Ehrich
authors.forename: Anette
authors.initials: A
authors.lastname: Melk
mesh_terms: D000328:Adult; D000368:Aged; D053222:Fas Ligand Protein; D005260:Female; D015870:Gene Expression; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D006801:Humans; D016753:Interleukin-10 / Q000235:genetics*; D007672:Kidney Cortex / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D016212:Transforming Growth Factor beta / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases