title: The nitric oxide-sensitive p21Ras-ERK pathway mediates S-nitrosoglutathione-induced apoptosis.
abstract: p21Ras protein plays a critical role in cellular signaling that induces either cell cycle progression or apoptosis. Nitric oxide (NO) has been consistently reported to activate p21Ras through the redox sensitive cysteine residue (118). In this study, we demonstrated that the p21Ras-ERK pathway regulates THP-1 monocyte/macrophage apoptosis induced by S-nitrosoglutathione (SNOG). This was apparent from studies in THP-1 cells expressing NO-insensitive p21Ras (p21Ras(C118S)) where the pro-apoptotic action of SNOG was almost abrogated. Three major MAP kinase pathways (ERK, JNK, and p38) that are downstream to p21Ras were investigated. It was observed that only the activation of ERK1/2 MAP kinases by SNOG in THP-1 cells was attributable to p21Ras. The inhibition of the ERK pathway by PD98059 markedly attenuated apoptosis in SNOG-treated THP-1 cells, but had a marginal effect on SNOG-treated THP-1 cells expressing NO-insensitive p21Ras. The inhibition of the JNK and p38 pathways by selective inhibitors had no marked effects on the percentage of apoptosis. The induction of p21Waf1 expression by SNOG was observed in THP-1 cells harboring mutant and wild-type p21Ras, however in cells expressing mutant Ras, the expression of p21Waf1 was significantly attenuated. The treatment of THP-1 cells expressing wild-type p21Ras with PD98059 resulted in significant attenuation of p21Waf1 expression. These results indicate that the redox sensitive p21Ras-ERK pathway plays a critical role in sensing and delivering the pro-apoptotic signaling mediated by SNOG.
authors.affiliation: Departamento de Bioquímica/Biologia Molecular, Centro Interdisciplinar de Terapia Gênica CINTERGEN, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
authors.forename: Maristela
authors.initials: M
authors.lastname: Tsujita
authors.forename: Wagner L
authors.initials: WL
authors.lastname: Batista
authors.forename: Fernando T
authors.initials: FT
authors.lastname: Ogata
authors.forename: Arnold
authors.initials: A
authors.lastname: Stern
authors.forename: Hugo P
authors.initials: HP
authors.lastname: Monteiro
authors.forename: Roberto J
authors.initials: RJ
authors.lastname: Arai
mesh_terms: D017209:Apoptosis; D002460:Cell Line; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000037:antagonists & inhibitors / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*; D026422:S-Nitrosoglutathione / Q000494:pharmacology
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D005419:Flavonoids; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras); C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one