title: Human RAGE antibody protects against AGE-mediated podocyte dysfunction.
abstract: BACKGROUND
  Residual renal function (RRF) contributes to better patient survival in peritoneal dialysis (PD). It is known that glucose degradation products (GDP) and advanced glycation end-products (AGE) resorbed from the peritoneal cavity do not only cause local peritoneal toxicity but also systemic damage resulting in a loss of RRF. We hypothesize that GDP and AGE affect the structure and function of podocytes and investigate whether these effects can be rescued by human RAGE antibody (hRAGEab) to prevent AGE/RAGE interaction and podocyte damage.
  
  
  METHODS
  Differentiated human podocytes were pre-incubated with ±hRAGEab to block the AGE/RAGE interaction and incubated afterwards either with control solution (control), PD fluid (PDF) or a GDP mixture (GDP) for 48 h. We analysed podocyte damage and rescue by hRAGEab using immunofluorescence, western blot, enzyme-linked immunosorbent assay and a functional migration assay. For quantitation, a semiquantitative score was used.
  
  
  RESULTS
  When pre-incubating podocytes with hRAGEab, damage mediated by PDF and GDP was reduced. We observed lower expression of AGE in PDF and GDP as well as decreased levels of inflammation as shown by activation of nuclear factor kappa B and interleukin-6 release. The reorganization of the podocyte actin cytoskeleton was reduced in the presence of hRAGEab as well as ameliorated synaptopodin expression could be observed, both functionally associated with normal podocyte motility. Finally, podocytes underwent less apoptosis.
  
  
  CONCLUSIONS
  It has been investigated that GDP-containing PDF causes a loss of RRF in PD. Our findings suggest that hRAGEab confers protection against PDF- and GDP-induced podocyte dysfunction. Blocking the AGE/RAGE interaction provides specific protective effects against PDF- and GDP-induced cytoskeletal reorganization, dynamics and stabilizes podocyte survival; this might be an implication for the preservation of RRF in PD.
authors.affiliation: Department of Nephrology, University of Heidelberg, Heidelberg, Germany. sandra.mueller@urz.uni-heidelberg.de
authors.forename: Sandra
authors.initials: S
authors.lastname: Müller-Krebs
authors.forename: Lars P
authors.initials: LP
authors.lastname: Kihm
authors.forename: Thati
authors.initials: T
authors.lastname: Madhusudhan
authors.forename: Berend
authors.initials: B
authors.lastname: Isermann
authors.forename: Jochen
authors.initials: J
authors.lastname: Reiser
authors.forename: Martin
authors.initials: M
authors.lastname: Zeier
authors.forename: Vedat
authors.initials: V
authors.lastname: Schwenger
mesh_terms: D000199:Actins / Q000378:metabolism; D000906:Antibodies / Q000008:administration & dosage; D017209:Apoptosis; D015415:Biomarkers / Q000378:metabolism; D002460:Cell Line; D022001:Focal Adhesions; D005947:Glucose / Q000378:metabolism; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008840:Microfilament Proteins / Q000378:metabolism; D008954:Models, Biological; D016328:NF-kappa B / Q000378:metabolism; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D050199:Podocytes / Q000276:immunology / Q000473:pathology / Q000502:physiology*; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000378:metabolism
chemical_list: D000199:Actins; D000906:Antibodies; D015415:Biomarkers; D017127:Glycation End Products, Advanced; C508600:IL6 protein, human; D039302:Integrin alphaVbeta3; D015850:Interleukin-6; D008840:Microfilament Proteins; D016328:NF-kappa B; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; C503967:SYNPO protein, human; D005947:Glucose