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Redox regulation of metabolic and signaling pathways by thioredoxin and glutaredoxin in NOS-3 overexpressing hepatoblastoma cells.

González R, López-Grueso MJ, Muntané J, Bárcena JA, Padilla CA - Redox Biol (2015)

Bottom Line: The aim of this study was to ascertain whether Trx and/or Grx systems mediate the antiproliferative effect of NO on hepatoblastoma cells by modulating the redox-state of key proteins.Silencing of Trx1 and Grx1 neutralized the increases in CD95, Akt1 and pAkt levels induced by NO and produced a marked increase in caspase-3 and -8 activities in both control and NOS-3 overexpressing cells concomitant with a decrease in the number of cells.These results demonstrate that the antiproliferative effect of NO is actually hampered by Trx1 and Grx1 and support the strategy of weakening the thiolic antioxidant defenses when designing new antitumoral therapies.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain. Electronic address: raulangello@hotmail.com.

No MeSH data available.


Related in: MedlinePlus

Effect of down-regulation of Grx and Trx on apoptosis. DNA fragmentation in cells detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). We have selected representing merged images of FITC and DAPI fluorescence of these treatments in the cell lineages studied (A). Apoptotic nuclei vs. total nuclei in percentage detected in different fluorescence images of control, siRNAGrx and siRNATrx treated cells in 3 independent experiments (B). The values labeled with “a” were significantly different (p≤0.05) versus the corresponding internal control in the same cell lineage. The values labeled with “b” were significantly different versus the corresponding control cell lineage.
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f0040: Effect of down-regulation of Grx and Trx on apoptosis. DNA fragmentation in cells detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). We have selected representing merged images of FITC and DAPI fluorescence of these treatments in the cell lineages studied (A). Apoptotic nuclei vs. total nuclei in percentage detected in different fluorescence images of control, siRNAGrx and siRNATrx treated cells in 3 independent experiments (B). The values labeled with “a” were significantly different (p≤0.05) versus the corresponding internal control in the same cell lineage. The values labeled with “b” were significantly different versus the corresponding control cell lineage.

Mentions: Nitrosative stress in HepG2 cells as a consequence of NOS3 overexpression results in reduction of cell number and proliferation (Fig. 7A and C) in agreement with a previous report [37]. In the current study we show that silencing Trx1 or Grx1 further decreased the number of cells and proliferation in all cell lineages and siRNATrx further reduced cell viability (Fig. 7A–C). siRNAGrx or siRNATrx treatments also provoked a striking increase in caspase-3 and caspase-8 activities in all cells (Fig. 7D and E), but lowered the levels of CD95 in NOS-3 overexpressing cells (Fig. 7F). Increase in caspases activities was actually accompanied by signs of increased apoptosis like DNA fragmentation as determined by TUNEL assay (Fig. 8). These results are worthy of consideration as they point to a moonlighting role of the redoxins depending on the prevailing cellular redox conditions as will be discussed in the next section (Fig. 9).


Redox regulation of metabolic and signaling pathways by thioredoxin and glutaredoxin in NOS-3 overexpressing hepatoblastoma cells.

González R, López-Grueso MJ, Muntané J, Bárcena JA, Padilla CA - Redox Biol (2015)

Effect of down-regulation of Grx and Trx on apoptosis. DNA fragmentation in cells detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). We have selected representing merged images of FITC and DAPI fluorescence of these treatments in the cell lineages studied (A). Apoptotic nuclei vs. total nuclei in percentage detected in different fluorescence images of control, siRNAGrx and siRNATrx treated cells in 3 independent experiments (B). The values labeled with “a” were significantly different (p≤0.05) versus the corresponding internal control in the same cell lineage. The values labeled with “b” were significantly different versus the corresponding control cell lineage.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4528045&req=5

f0040: Effect of down-regulation of Grx and Trx on apoptosis. DNA fragmentation in cells detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). We have selected representing merged images of FITC and DAPI fluorescence of these treatments in the cell lineages studied (A). Apoptotic nuclei vs. total nuclei in percentage detected in different fluorescence images of control, siRNAGrx and siRNATrx treated cells in 3 independent experiments (B). The values labeled with “a” were significantly different (p≤0.05) versus the corresponding internal control in the same cell lineage. The values labeled with “b” were significantly different versus the corresponding control cell lineage.
Mentions: Nitrosative stress in HepG2 cells as a consequence of NOS3 overexpression results in reduction of cell number and proliferation (Fig. 7A and C) in agreement with a previous report [37]. In the current study we show that silencing Trx1 or Grx1 further decreased the number of cells and proliferation in all cell lineages and siRNATrx further reduced cell viability (Fig. 7A–C). siRNAGrx or siRNATrx treatments also provoked a striking increase in caspase-3 and caspase-8 activities in all cells (Fig. 7D and E), but lowered the levels of CD95 in NOS-3 overexpressing cells (Fig. 7F). Increase in caspases activities was actually accompanied by signs of increased apoptosis like DNA fragmentation as determined by TUNEL assay (Fig. 8). These results are worthy of consideration as they point to a moonlighting role of the redoxins depending on the prevailing cellular redox conditions as will be discussed in the next section (Fig. 9).

Bottom Line: The aim of this study was to ascertain whether Trx and/or Grx systems mediate the antiproliferative effect of NO on hepatoblastoma cells by modulating the redox-state of key proteins.Silencing of Trx1 and Grx1 neutralized the increases in CD95, Akt1 and pAkt levels induced by NO and produced a marked increase in caspase-3 and -8 activities in both control and NOS-3 overexpressing cells concomitant with a decrease in the number of cells.These results demonstrate that the antiproliferative effect of NO is actually hampered by Trx1 and Grx1 and support the strategy of weakening the thiolic antioxidant defenses when designing new antitumoral therapies.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain. Electronic address: raulangello@hotmail.com.

No MeSH data available.


Related in: MedlinePlus