title: A pharmacologically-based array to identify targets of cyclosporine A-induced toxicity in cultured renal proximal tubule cells.
abstract: Mechanisms of cyclosporine A (CsA)-induced nephrotoxicity were generally thought to be hemodynamic in origin; however, there is now accumulating evidence of a direct tubular effect. Although genomic and proteomic experiments by our group and others provided overall information on genes and proteins up- or down-regulated by CsA in proximal tubule cells (PTC), a comprehensive view of events occurring after CsA exposure remains to be described. For this purpose, we applied a pharmacologic approach based on the use of known activities of a large panel of potentially protective compounds and evaluated their efficacy in preventing CsA toxicity in cultured mouse PTC. Our results show that compounds that blocked protein synthesis and apoptosis, together with the CK2 inhibitor DMAT and the PI3K inhibitor apigenin, were the most efficient in preventing CsA toxicity. We also identified GSK3, MMPs and PKC pathways as potential targets to prevent CsA damage. Additionally, heparinase-I and MAPK inhibitors afforded partial but significant protection. Interestingly, antioxidants and calcium metabolism-related compounds were unable to ameliorate CsA-induced cytotoxicity. Subsequent experiments allowed us to clarify the hierarchical relationship of targeted pathways after CsA treatment, with ER stress identified as an early effector of CsA toxicity, which leads to ROS generation, phenotypical changes and cell death. In summary, this work presents a novel experimental approach to characterizing cellular responses to cytotoxics while pointing to new targets to prevent CsA-induced toxicity in proximal tubule cells.
authors.affiliation: Departament de Bioquímica i Biologia Molecular, Unitat de Bioquímica de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain. eduard.sarro@vhir.org
authors.forename: Eduard
authors.initials: E
authors.lastname: Sarró
authors.forename: Conxita
authors.initials: C
authors.lastname: Jacobs-Cachá
authors.forename: Emilio
authors.initials: E
authors.lastname: Itarte
authors.forename: Anna
authors.initials: A
authors.lastname: Meseguer
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D016572:Cyclosporine / Q000633:toxicity*; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D006801:Humans; D007166:Immunosuppressive Agents / Q000633:toxicity*; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000473:pathology; D020782:Matrix Metalloproteinases / Q000378:metabolism; D051379:Mice; D011493:Protein Kinase C / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D007166:Immunosuppressive Agents; D017382:Reactive Oxygen Species; D016572:Cyclosporine; D011493:Protein Kinase C; D038362:Glycogen Synthase Kinase 3; D020782:Matrix Metalloproteinases