Role for TGF-beta in cyclosporine-induced modulation of renal epithelial barrier function.
It was previously shown that cyclosporine A (CsA) increases transepithelial resistance in MDCK cells. Activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) cascade seems to be pivotal to the CsA-induced increase in transepithelial electrical resistance (TER). This study examined the role played by TGF-beta in mediating the CsA-induced activation of ERK1/2 and the resulting increase in TER in MDCK cells. Paracellular permeability across MDCK monolayers after various treatments was assessed by measurement of TER. TGF-beta secretion was measured by Western blot and ELISA. Activation of the ERK1/2 pathway and tight junction protein expression were also assessed by Western blot analysis. CsA increased production and secretion of TGF-beta and expression of the TGF-beta receptor II. Exogenous addition of TGF-beta1 activated ERK1/2 and increased TER across MDCK monolayers, both of which were attenuated by the MEK inhibitor U0126. Neutralizing antibodies against TGF-beta1 and the TGF-beta receptor II significantly reduced the CsA-induced increase in TER. Both CsA and TGF-beta1 increased expression of tight junction proteins claudin-1 and zonula occludens 2. Inhibition of the p38 MAPK pathway also attenuated the TGF-beta1-induced increase in TER. The results presented here suggest that the CsA-induced modulation of paracellular permeability may be mediated, at least in part, by an increase in TGF-beta production.
Feldman
Gemma
G
Department of Pharmacology, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland.
Kiely
Breda
B
Martin
Natalia
N
Ryan
Gavin
G
McMorrow
Tara
T
Ryan
Michael P
MP
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002070:Butadienes / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D016572:Cyclosporine / Q000494:pharmacology*; D003911:Dextrans / Q000493:pharmacokinetics; D004285:Dogs; D017097:Electric Impedance; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D007093:Imidazoles / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007668:Kidney / Q000166:cytology; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000276:immunology / Q000378:metabolism*
D000906:Antibodies; D002070:Butadienes; D003911:Dextrans; D004791:Enzyme Inhibitors; D007093:Imidazoles; D007166:Immunosuppressive Agents; D009570:Nitriles; D011725:Pyridines; D018125:Receptors, Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C113580:U 0126; C015219:fluorescein isothiocyanate dextran; D016572:Cyclosporine; D017346:Protein Serine-Threonine Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020930:MAP Kinase Kinase Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II; D016650:Fluorescein-5-isothiocyanate; C093642:SB 203580