title: The protective effects of erythropoietin on rat glomerular podocytes in culture are modulated by extracellular matrix proteins.
abstract: OBJECTIVE
  Podocytes are typically cultured on collagen I; however, collagen I is absent from healthy glomerular basement membranes. Erythropoietin (EPO) is thought to protect podocytes in vivo. Here, we studied how various types of extracellular matrix (ECM) proteins and EPO affect podocytes in culture.
  
  
  METHODS
  Primary rat podocytes were replated on collagen I, collagen IV, whole ECM extract, laminin, or bare plastic. Cellular adhesion (8 hours after plating), proliferation (5 days, 10 % serum), and resistance to serum deprivation (3 days, 0.5 % serum) were assessed. BrdU incorporation and expression of podocyte-specific markers were employed as measures of cellular proliferation and differentiation, respectively. qPCR was used to verify expression of EPO receptor in cultured podocytes.
  
  
  RESULTS
  Cellular adhesion was similar on all ECM proteins and unaffected by EPO. Proliferation was accelerated by laminin and the ECM extract, but the final cell density was similar on all ECM surfaces. Collagen IV supported the serum-deprived cells better than the other ECM proteins. EPO (2-20 ng/ml) improved viability of serum-deprived podocytes on collagen I, collagen IV, and ECM, but not on laminin or bare plastic. The cells expressed mRNA for EPO receptor.
  
  
  CONCLUSIONS
  The physiological ECM proteins are more supportive of primary podocytic cultures compared with collagen I. The protective effects of EPO during serum deprivation are modulated by the cultivation surface.
authors.affiliation: Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Krtil
authors.forename: Jan
authors.initials: J
authors.lastname: Pláteník
authors.forename: Nikola
authors.initials: N
authors.lastname: Čuřík
authors.forename: Wunnie
authors.initials: W
authors.lastname: Brima
authors.forename: Vladimír
authors.initials: V
authors.lastname: Tesař
authors.forename: Tomáš
authors.initials: T
authors.lastname: Zima
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004396:Coloring Agents; D004921:Erythropoietin / Q000494:pharmacology*; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000502:physiology*; D007678:Kidney Glomerulus / Q000187:drug effects*; D050199:Podocytes / Q000187:drug effects*; D061251:Primary Cell Culture; D051381:Rats; D017467:Receptors, Erythropoietin / Q000096:biosynthesis / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D004396:Coloring Agents; D016326:Extracellular Matrix Proteins; D017467:Receptors, Erythropoietin; D011994:Recombinant Proteins; D013778:Tetrazolium Salts; D013844:Thiazoles; D004921:Erythropoietin; C022616:thiazolyl blue