Interleukin-4 and -13 promote basolateral secretion of H(+) and cathepsin L by glomerular epithelial cells.
Minimal change nephrosis (MCN) is characterized by massive proteinuria and ultrastructural alterations of glomerular visceral epithelial cells (GVEC). MCN has been associated with elevated production of interleukin (IL)-13 by circulating T lymphocytes and with T helper 2 lymphocyte-dependent conditions. We recently showed that GVEC express IL-4 and IL-13 receptors and that IL-4 and IL-13 increase transcellular ion transport over GVEC monolayers. We therefore hypothesized that IL-13 may directly injure GVEC. Here we demonstrate that IL-4 and IL-13 induce bafilomycin A1-sensitive basolateral proton secretion by cultured GVEC, indicating involvement of vacuolar H(+)-ATPase. The effects of IL-4 and IL-13 were accompanied by redistribution of the small GTPases Rab5b and Rab7, as shown by confocal immunofluorescence studies. Furthermore, Western blot analysis and assays for cysteine proteinase activity revealed basolateral secretion of the lysosomal proteinase procathepsin L by cultured GVEC, stimulated by IL-4 and IL-13. We speculate that IL-4 and IL-13 influence intracellular trafficking of proteins and promote proteolysis at the basolateral surface of GVEC, which may play a pathogenic role in altered glomerular permeability.
Van Den Berg
José G
JG
Department of Pathology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands. j.g.vandenberg@amc.uva.nl
Aten
Jan
J
Annink
Carla
C
Ravesloot
Jan H
JH
Weber
Ekkehard
E
Weening
Jan J
JJ
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001485:Basement Membrane / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D056668:Cathepsin L; D002403:Cathepsins / Q000378:metabolism*; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018793:Interleukin-13 / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D007678:Kidney Glomerulus / Q000166:cytology / Q000378:metabolism*; D018942:Macrolides; D009402:Nephrosis, Lipoid / Q000378:metabolism; D011522:Protons; D051381:Rats; D025262:Vacuolar Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000378:metabolism; D020696:rab5 GTP-Binding Proteins / Q000378:metabolism; D000090802:rab7 GTP-Binding Proteins
D000276:Adjuvants, Immunologic; D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D018793:Interleukin-13; D018942:Macrolides; D011522:Protons; D000090802:rab7 GTP-Binding Proteins; C000716466:rab7 GTP-binding proteins, rat; C057620:bafilomycin A; D015847:Interleukin-4; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D056668:Cathepsin L; C534280:Ctsl protein, rat; D025262:Vacuolar Proton-Translocating ATPases; D020691:rab GTP-Binding Proteins; D020696:rab5 GTP-Binding Proteins