title: Expression of CD27 and ischemia/reperfusion-induced expression of its ligand Siva in rat kidneys.
abstract: BACKGROUND
  Studies identifying genes that are differentially expressed following induction of acute ischemic injury have been useful in delineating the pathophysiology of acute renal failure.
  
  
  METHODS
  A differential cDNA library screening technique was used to identify genes that are differentially expressed in rat kidney following induction of acute ischemic renal injury.
  
  
  RESULTS
  Levels of mRNA with a high homology to that coding for Siva, a human proapoptotic protein, were increased approximately 4.5-fold in kidneys obtained from rats within 12 hours following ischemia, compared to kidneys from sham-operated rats. A partial cDNA sequence for the rat protein (rat Siva) was determined that overlaps 92% of the human open reading frame. The cDNA sequence predicts a protein 177 amino acids in length with 76% homology to human Siva. Levels of rat Siva in kidneys were elevated at one, five and seven days post-ischemia were not different from those in kidneys from sham-operated controls. In situ hybridization demonstrated that rat Siva mRNA was expressed in cells lining damaged sections in the S3 segment of the proximal tubule at 12 hours and one day post-ischemia. At five and seven days, Siva mRNA was located in epithelial cells of regenerating tubules including in papillary proliferations. TdT-mediated dUTP-biotin nick end-labeling (TUNEL)-positive cells colocalized with cells containing Siva mRNA. CD27, the receptor for Siva was localized by immunohistochemistry to sloughed cells in the lumens of damaged S3 segments at 12 hours post-ischemia and to cells within papillary proliferations at five days post-injury.
  
  
  CONCLUSIONS
  Siva that is produced within the kidney could be a mediator of apoptosis post-ischemia via an interaction with CD27.
authors.affiliation: George M. O'Brien Kidney and Urological Diseases Center, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Padanilam
authors.forename: A J
authors.initials: AJ
authors.lastname: Lewington
authors.forename: M R
authors.initials: MR
authors.lastname: Hammerman
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D051017:Apoptosis Regulatory Proteins; D001483:Base Sequence / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007511:Ischemia / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012079:Renal Circulation / Q000502:physiology; D015427:Reperfusion Injury / Q000378:metabolism*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; C106549:SIVA1 protein, human; C484570:Siva1 protein, rat; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7