Inhibition of p38-MAPK potentiates cisplatin-induced apoptosis via GSH depletion and increases intracellular drug accumulation in growth-arrested kidney tubular epithelial cells

Autor: Alberto Ortiz, Patricio Aller, Felicísima Mata, Adoración G. Quiroga, Maria Elena Rodríguez-García, José Castro
Rok vydání: 2009
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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ISSN: 1096-0929
Popis: 11 páginas, 8 figuras -- PAGS nros. 413-423
We were interested in analyzing the regulation by mitogen-activated protein kinases (MAPKs) of cisplatin-provoked toxicity in epithelial renal tubule cell lines, when assayed under culture conditions (cell confluence plus serum deprivation), which mimic the characteristics of a nonproliferating epithelium. Under these restrictive growth conditions, cisplatin induced apoptosis with lower efficacy than in exponentially growing cells, and decreased p38-MAPK phosphorylation in NRK-52E and other (LLC-PK1, MDCK, HK2) cell lines. Moreover, cisplatin-provoked apoptosis was potentiated by cotreatment with p38-MAPK–specific inhibitors (SB203580, SB220025) or transfection with a kinase-negative mutant of MKK6, whereas c-Jun NH2-terminal kinase or extracellular signal-regulated kinase/MAPK and ERK Kinase inhibitors were ineffective. By contrast, when applied to exponentially growing cells, cisplatin stimulated p38-MAPK phosphorylation and apoptosis, was attenuated by kinase inhibitors. Treatment of confluent/serum-deprived cells with cisplatin caused mitochondrial transmembrane potential disruption and activated the mitochondrial apoptotic pathway, as indicated by the decrease in Bcl-XL expression, increase in Bax expression and cytochrome c release, and these effects were potentiated by cotreatment with SB203580. Treatment of confluent/serum-deprived cells with cisplatin plus SB203580 decreased the intracellular reduced glutathione (GSH) content, and increased intracellular cisplatin accumulation as well as cisplatin binding to DNA. Cotreatment with the GSH-depleting agent D,L-buthionine-R,S-sulfoximine also potentiated cisplatin-provoked apoptosis. In summary, p38-MAPK inhibition potentiates cisplatin-provoked apoptosis in growth-arrested epithelial renal tubule cells, a result that may be explained at least in part by GSH depletion and drug transport alteration
Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, Ministerio de Educación y Ciencia, Spain, Grants (SAF2006-03296, SAF2007-64721, and CSD2007-00020) (Programa Consolider-Ingenio 2010); and Universidad Complutense de Madrid predoctoral fellowship to M.E.R.
Databáze: OpenAIRE