scholarly journals Redox up-regulated expression of rat liver manganese superoxide dismutase and Bcl-2 by thyroid hormone is associated with inhibitor of κB-α phosphorylation and nuclear factor-κB activation

2005 ◽  
Vol 186 (3) ◽  
pp. 539-547 ◽  
Author(s):  
Virginia Fernández ◽  
Gladys Tapia ◽  
Patricia Varela ◽  
Iván Castillo ◽  
Catalina Mora ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Dna Binding ◽  
Rat Liver ◽  
Manganese Superoxide Dismutase ◽  
Nuclear Factor Κb ◽  
Protective Mechanism ◽  
Time Interval ◽  
Nuclear Factor ◽  
Manganese Superoxide ◽  
Tnf Α

Recently, we demonstrated that 3,3′,5-triiodothyronine (T3) induces oxidative stress in rat liver, with enhancement in the DNA binding of nuclear factor-κB (NF-κB) and the NF-κB-dependent expression of tumor necrosis factor-α (TNF-α). In this study, we show that T3 administration (daily doses of 0.1 mg/kg i.p. for three consecutive days) elicited a calorigenic response and higher liver O2 consumption rates, with increased serum levels of TNF-α (ELISA), liver inhibitor of κB (IκB-α) phosphorylation (Western blot analysis), and hepatic NF-κB DNA binding (EMSA) at 56–72 h after treatment. Within this time interval, liver manganese superoxide dismutase (MnSOD) activity and the protein expression of MnSOD and Bcl-2 are enhanced. These changes are abrogated by the administration of α-tocopherol (100 mg/kg i.p.) prior to T3. It is concluded that T3 treatment leads to the redox upregulation of MnSOD and Bcl-2 in rat liver, in association with TNF-α release and activation of the IκB-α kinase/NF-κB cascade, which may constitute a protective mechanism against free radical toxicity involving cell death signaling.

scholarly journals Radon inhalation induces manganese-superoxide dismutase in mouse brain via nuclear factor-κB activation

2017 ◽  
Vol 58 (6) ◽  
pp. 887-893 ◽  
Author(s):  
Takahiro Kataoka ◽  
Reo Etani ◽  
Norie Kanzaki ◽  
Yusuke Kobashi ◽  
Yuto Yunoki ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Mouse Brain ◽  
Manganese Superoxide Dismutase ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Ataxia Telangiectasia Mutated ◽  
Sod Activity ◽  
Manganese Superoxide ◽  
Radon Inhalation ◽  
The Brain

Abstract Although radon inhalation increases superoxide dismutase (SOD) activities in mouse organs, the mechanisms and pathways have not yet been fully clarified. The aim of this study was to determine the details of SOD activation in mouse brain tissue following the inhalation of radon at concentrations of 500 or 2000 Bq/m3 for 24 h. After inhalation, brains were removed quickly for analysis. Radon inhalation increased the manganese (Mn)-SOD level and mitochondrial SOD activity. However, the differences were not significant. There were no changes in the Cu/Zn-SOD level or cytosolic SOD activity. Radon inhalation increased the brain nuclear factor (NF)-κB content, which regulates the induction of Mn-SOD, in the nuclear and cytosolic compartments. The level of inhibitor of nuclear factor κB kinase subunit β (IKK-β), which activates NF-κB, was slightly increased by radon inhalation. The expression of cytoplasmic ataxia-telangiectasia mutated kinase in mice inhaling radon at 500 Bq/m3 was 50% higher than in control mice. In addition, NF-κB–inducing kinase was slightly increased after inhaling radon at 2000 Bq/m3. These findings suggest that radon inhalation might induce Mn-SOD protein via NF-κB activation that occurs in response to DNA damage and oxidative stress.

A direct requirement of nuclear factor-κB for suppression of apoptosis in ventricular myocytes

2000 ◽  
Vol 279 (3) ◽  
pp. H939-H945 ◽  
Author(s):  
Shareef Mustapha ◽  
Alla Kirshner ◽  
Danielle De Moissac ◽  
Lorrie A. Kirshenbaum
Keyword(s):  
Dna Binding ◽  
Gene Transcription ◽  
Ventricular Myocytes ◽  
Vital Staining ◽  
Fold Increase ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Cytoplasmic Factor ◽  
Tnf Α ◽  
Factor Α

Nuclear factor-κB (NF-κB) is a ubiquitously expressed cellular factor regulated by the cytoplasmic factor inhibitor protein κBα (IκBα). Activation of NF-κB by cytokines, including tumor necrosis factor-α (TNF-α), requires the phosphorylation and degradation of IκBα. An anti-apoptotic role for NF-κB has recently been suggested. In the present study, we ascertained whether death-promoting signals and apoptosis mediated by TNF-α are suppressed by NF-κB in postnatal ventricular myocytes. Stimulation of myocytes with TNF-α resulted in a 12.1-fold increase ( P < 0.01) in NF-κB-dependent gene transcription and DNA binding compared with controls. This was accompanied by a corresponding increase in the NF-κB target protein A20 as determined by Western blot analysis. Vital staining revealed that TNF-α was not cytotoxic to myocytes and did not provoke apoptosis. Adenovirus-mediated delivery of a nonphosphorylatable form of IκBα to inactivate NF-κB prevented TNF-α-stimulated NF-κB-dependent gene transcription and nuclear NF-κB DNA binding. Importantly, myocytes stimulated with TNF-α and defective for NF-κB activation resulted in a 2.2-fold increase ( P < 0.001) in apoptosis. To our knowledge, the data provide the first indication that a functional NF-κB signaling pathway is crucial for suppressing death-promoting signals mediated by TNF-α in ventricular myocytes.

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