title: Thioredoxin-1 promotes survival in cells exposed to S-nitrosoglutathione: Correlation with reduction of intracellular levels of nitrosothiols and up-regulation of the ERK1/2 MAP Kinases.
abstract: Accumulating evidence indicates that post-translational protein modifications by nitric oxide and its derived species are critical effectors of redox signaling in cells. These protein modifications are most likely controlled by intracellular reductants. Among them, the importance of the 12 kDa dithiol protein thioredoxin-1 (TRX-1) has been increasingly recognized. However, the effects of TRX-1 in cells exposed to exogenous nitrosothiols remain little understood. We investigated the levels of intracellular nitrosothiols and survival signaling in HeLa cells over-expressing TRX-1 and exposed to S-nitrosoglutahione (GSNO). A role for TRX-1 expression on GSNO catabolism and cell viability was demonstrated by the concentration-dependent effects of GSNO on decreasing TRX-1 expression, activation of caspase-3, and increasing cell death. The over-expression of TRX-1 in HeLa cells partially attenuated caspase-3 activation and enhanced cell viability upon GSNO treatment. This was correlated with reduction of intracellular levels of nitrosothiols and increasing levels of nitrite and nitrotyrosine. The involvement of ERK, p38 and JNK pathways were investigated in parental cells treated with GSNO. Activation of ERK1/2 MAP kinases was shown to be critical for survival signaling. In cells over-expressing TRX-1, basal phosphorylation levels of ERK1/2 MAP kinases were higher and further increased after GSNO treatment. These results indicate that the enhanced cell viability promoted by TRX-1 correlates with its capacity to regulate the levels of intracellular nitrosothiols and to up-regulate the survival signaling pathway mediated by the ERK1/2 MAP kinases.
authors.affiliation: Department of Biochemistry/Molecular Biology, CINTERGEN, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua 3 de Maio no. 100, 4 degrees andar, CEP 04044-020, São Paulo, SP, Brazil. arairj@yahoo.com.br
authors.forename: Roberto J
authors.initials: RJ
authors.lastname: Arai
authors.forename: Fernando T
authors.initials: FT
authors.lastname: Ogata
authors.forename: Wagner L
authors.initials: WL
authors.lastname: Batista
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Masutani
authors.forename: Junji
authors.initials: J
authors.lastname: Yodoi
authors.forename: Victor
authors.initials: V
authors.lastname: Debbas
authors.forename: Ohara
authors.initials: O
authors.lastname: Augusto
authors.forename: Arnold
authors.initials: A
authors.lastname: Stern
authors.forename: Hugo P
authors.initials: HP
authors.lastname: Monteiro
mesh_terms: D053148:Caspase 3 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006367:HeLa Cells; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D026422:S-Nitrosoglutathione / Q000008:administration & dosage / Q000494:pharmacology*; D026403:S-Nitrosothiols / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013879:Thioredoxins / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D009573:Nitrites; D026403:S-Nitrosothiols; C002744:3-nitrotyrosine; D014443:Tyrosine; D013879:Thioredoxins; D026422:S-Nitrosoglutathione; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D053148:Caspase 3