Nitric oxide-induced reduction of lung cell and whole lung thioredoxin expression is regulated by NF-κB

1999 ◽  
Vol 277 (4) ◽  
pp. L787-L793 ◽  
Author(s):  
Jianliang Zhang ◽  
Leonard W. Velsor ◽  
Jawaharlal M. Patel ◽  
Edward M. Postlethwait ◽  
Edward R. Block
Keyword(s):  
Nitric Oxide ◽  
Dna Binding ◽  
Nuclear Factor Κb ◽  
Binding Activity ◽  
Nuclear Fraction ◽  
Cytosol Fraction ◽  
Intact Mouse ◽  
Α Subunit ◽  
Dna Binding Activity ◽  
Mouse Lungs

We examined whether nitric oxide (NO)-induced inhibition of thioredoxin (Thx) expression is regulated by a mechanism mediated by a transcription factor, i.e., nuclear factor-κB (NF-κB), in cultured porcine pulmonary artery endothelial cells (PAEC) and in mouse lungs. Western blot analysis revealed that IκB-α content was reduced by 20 and 60% in PAEC exposed to 8.5 ppm NO for 2 and 24 h, respectively. NO exposure also caused significant reductions of cytosol fraction p65 and p52 content in PAEC. The nuclear fraction p65 and p52 contents were significantly reduced only in PAEC exposed to NO for 24 h. Exposure to NO resulted in a 50% reduction of p52 mRNA but not of the IκB-α subunit. DNA binding activity of the oligonucleotide encoding the NF-κB sequence in the Thxgene was significantly reduced in PAEC exposed to NO for 24 h. Exposure of mice to 10 ppm NO for 24 h resulted in a significant reduction of lung Thx and IκB-α mRNA and protein expression and in the oligonucleotide encoding Thx and NF-κB/DNA binding. These results 1) demonstrate that the effects of NO exposure on Thx expression in PAEC are comparable to those observed in intact lung and 2) suggest that reduced expression of the NF-κB subunit, leading to reduced NF-κB/DNA binding, is associated with the loss of Thx expression in PAEC and in intact mouse lungs.

UV stimulation induces nuclear factor κB (NF-κB) DNA-binding activity but not transcriptional activation

2001 ◽  
Vol 29 (6) ◽  
pp. 688-691 ◽  
Author(s):  
K. J. Campbell ◽  
N. R. Chapman ◽  
N. D. Perkins
Keyword(s):  
Dna Binding ◽  
Transcriptional Activation ◽  
Cellular Response ◽  
Uv Light ◽  
Binding Protein ◽  
Nuclear Factor Κb ◽  
Camp Response Element Binding ◽  
Binding Activity ◽  
Nuclear Factor ◽  
Dna Binding Activity

The cellular response to DNA-damaging agents is partly mediated by DNA-binding transcription factors such as p53 and nuclear factor κB (NF-κB). Typically NF-κB activation is associated with resistance to apoptosis. Following stimulation with UV light however, NF-κB activation has been shown to be required for programmed cell death. To study this effect further and to determine the relationship between NF-κB and p53 function, we have examined the effect of UV light on U2OS cells. UV stimulation resulted in the activation of NF-κB DNA-binding and the induction of p53. Surprisingly, and in contrast with tumour necrosis factor α stimulation, this UV-induced NF-κB was transcriptionally inert. These observations suggest a model in which the NF-κB switch from an anti-apoptotic to a pro-apoptotic role within the cell results from modulation of its ability to stimulate gene expression, possibly as a result of the ability of p53 to sequester transcriptional co-activator proteins such as p300/CREB (cAMP-response-element-binding protein)-binding protein.

p65 controls NF-κB activity by regulating cellular localization of IκBβ

2011 ◽  
Vol 434 (2) ◽  
pp. 253-263 ◽  
Author(s):  
Taras Valovka ◽  
Michael O. Hottiger
Keyword(s):  
Dna Binding ◽  
Nuclear Export ◽  
Cellular Localization ◽  
Nuclear Export Signal ◽  
Nuclear Factor Κb ◽  
Binding Activity ◽  
Cellular Processes ◽  
Dna Binding Activity ◽  
Localization Signal ◽  
Export Signal

NF-κB (nuclear factor κB) controls diverse cellular processes and is frequently misregulated in chronic immune diseases or cancer. The activity of NF-κB is regulated by IκB (inhibitory κB) proteins which control nuclear–cytoplasmic shuttling and DNA binding of NF-κB. In the present paper, we describe a novel role for p65 as a critical regulator of the cellular localization and functions of NF-κB and its inhibitor IκBβ. In genetically modified p65−/− cells, the localization of ectopic p65 is not solely regulated by IκBα, but is largely dependent on the NLS (nuclear localization signal) and the NES (nuclear export signal) of p65. Furthermore, unlike IκBα, IκBβ does not contribute to the nuclear export of p65. In fact, the cellular localization and degradation of IκBβ is controlled by the p65-specific NLS and NES. The results of our present study also reveal that, in addition to stimulus-induced redistribution of NF-κB, changes in the constitutive localization of p65 and IκBβ specifically modulate activation of inflammatory genes. This is a consequence of differences in the DNA-binding activity and signal responsiveness between the nuclear and cytoplasmic NF-κB–IκBβ complexes. Taken together, the findings of the present study indicate that the p65 subunit controls transcriptional competence of NF-κB by regulating the NF-κB/IκBβ pathway.

Abstract WMP81: FGF21 Reduces Post-Stroke Blood Brain Barrier Damage in Diabetic db/db Male Mice

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Yinghua Jiang ◽  
Ning Liu ◽  
Xiaoying Wang
Keyword(s):  
Dna Binding ◽  
Binding Activity ◽  
Junctional Complex ◽  
Fibroblast Growth Factor 21 ◽  
Nuclear Fraction ◽  
Mrna Levels ◽  
Protective Effects ◽  
Post Stroke ◽  
Dna Binding Activity ◽  
Bbb Permeability

Background and Purpose: Our previous studies demonstrated that recombinant human Fibroblast growth factor 21 (rFGF21), an endocrine member of the FGF family is potently beneficial for improving long-term neurological outcomes of type 2 diabetes (T2D) stroke mice. Here we tested hypothesis that rFGF21 protects against post-stroke BBB damage by PPARγ activation of cerebral micovascular endothelium. Methods: T2D db/db mice and their non-diabetic counterparts db/+ mice were subjected to focal stroke of dMCAO. Four experimental groups: 1) db/+ stroke, 2) db/db stroke, 3) db/db stroke+rFGF21, and 4) db/db stroke+rFGF21+GW9662. rFGF21 (1.5mg/kg, i.p.) was injected at 6 hours after stroke and PPARγ inhibitor GW9662 (4mg/kg, i.p.) was injected 30 min prior to rFGF21 treatment. At 24 hours post-stroke, we collected peri-infarct nuclear fraction for PPARγ-DNA binding activity assay using EMSA, microvascular isolation for RT-PCR analyzing mRNA levels of proteins constituting BBB junctional complex (occluding, clauding-5, VE-cadherin and ZO-1) and PPARγ targeted downstream genes (CD36 and FABP4) as indicators of PPARγ activity in microvasculature. BBB permeability was assessed by measuring 3kDa FITC-dextran or Evans blue extravasations at 48 hour post-stroke. Results: Ischemic stroke induced a significant decrease of PPARγ-DNA binding activity and mRNA levels of BBB junctional proteins in peri-infarct area, and a significant increase of BBB permeability in diabetic db/db stroke mice compared to db/+ stroke mice. Changes of mRNA levels of CD36 and FABP4 in brain microvascular isolation were consistent with changes of PPARγ-DNA binding activity. rFGF21 administration significantly increased PPARγ-DNA binding activity, elevated mRNA levels of BBB junctional complex proteins and ameliorated BBB leakage. However, pre-treatment of GW9662 partially abolished the post-stroke BBB protective effects of rFGF21. Conclusions: rFGF21 has strong protective effects in acute BBB leakage after stroke, and the underlying mechanisms is partially via increase in PPARγ-DNA binding activity and mRNA expression of BBB junctional complex proteins. Together with our previous investigations, rFGF21 might be a promising candidate for treating diabetic stroke.

scholarly journals Age alters cerebrovascular inflammation and effects of estrogen

2007 ◽  
Vol 292 (5) ◽  
pp. H2333-H2340 ◽  
Author(s):  
Lorraine Sunday ◽  
Christa Osuna ◽  
Diana N. Krause ◽  
Sue P. Duckles
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Dna Binding ◽  
Inducible Nitric Oxide Synthase ◽  
Binding Activity ◽  
Cerebral Vessels ◽  
Cerebral Blood Vessels ◽  
Dna Binding Activity ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

In young adult females, estrogen treatment suppresses the cerebrovascular inflammatory response; this is mediated in part via NF-κB, a key regulator of inflammatory genes. To examine whether age modifies effects of estrogen on vascular inflammation in the brain, female rats, 3 and 12 mo of age, were ovariectomized; half were treated with estrogen for 4 wk. Cerebral blood vessels were isolated from the animals at 4 and 13 mo of age. Inflammation was induced by LPS, either injected in vivo or incubated with isolated vessels ex vivo. Basal levels of cytoplasmic NF-κB were significantly higher in cerebral vessels of young rats, but the ratio of nuclear to cytoplasmic levels was greater in middle-aged animals. LPS exposure increased nuclear NF-κB DNA binding activity, protein levels of inducible nitric oxide synthase and cyclooxygenase-2, and production of nitric oxide and PGE2 in cerebral vessels. All effects of LPS were markedly greater in vessels from the older animals. Estrogen significantly inhibited the LPS-induced increase in NF-κB DNA binding activity in cerebral vessels from animals at both ages. In 4-mo-old rats, estrogen also significantly suppressed LPS induction of inducible nitric oxide synthase and cyclooxygenase-2 proteins, as well as production of nitric oxide and PGE2. In contrast, in 13-mo-old females, estrogen did not significantly affect these indexes of cerebrovascular inflammation. Thus the protective, anti-inflammatory effect of estrogen on cerebral blood vessels that is observed in young adults may be attenuated in aged animals, which exhibit a greater overall cerebrovascular response to inflammatory stimuli.

scholarly journals UV-A-induced decrease in nuclear factor-κB activity in human keratinocytes

1999 ◽  
Vol 338 (3) ◽  
pp. 607-613 ◽  
Author(s):  
Mojgan DJAVAHERI-MERGNY ◽  
Marie-Pierre GRAS ◽  
Jean-Louis MERGNY ◽  
Louis DUBERTRET
Keyword(s):  
Gene Expression ◽  
Dna Binding ◽  
Uv Radiation ◽  
Human Keratinocytes ◽  
Nuclear Factor Κb ◽  
Binding Activity ◽  
Luciferase Reporter ◽  
Nuclear Factor ◽  
Protein Subunits ◽  
Dna Binding Activity

Previous reports have demonstrated an increase in nuclear factor-κB (NF-κB) activity in response to UV radiation. These studies have essentially focused on the DNA-damaging fraction of solar UV radiation (UV-B and UV-C). In contrast, the effects of UV-A radiation (320–400 nm) on NF-κB are not well known. In this study, we present evidence that UV-A radiation induces a marked decrease in NF-κB DNA-binding activity in NCTC 2544 human keratinocytes. In addition, NCTC 2544 keratinocytes pretreated with UV-A fail to respond to NF-κB inducers. Moreover, UV-A radiation induces a decrease in NF-κB-driven luciferase reporter gene expression in NCTC 2544 keratinocytes. The expression of the gene encoding IκBα (IκB is the NF-κB inhibitor), which is closely associated with NF-κB activity, is also reduced (3-fold) upon UV-A treatment. Our results indicate that the UV-A-induced decrease in NF-κB DNA-binding activity is associated with a decrease in the levels of the p50 and p65 protein subunits. This is the first evidence that an oxidative stress, such as UV-A radiation, may induce a specific decrease in NF-κB activity in mammalian cells, probably through degradation of NF-κB protein subunits. These findings suggest that UV-A could modulate the NF-κB-dependent gene expression.

Decreased nuclear factor-κB DNA binding activity following permanent focal cerebral ischaemia in the rat

2000 ◽  
Vol 288 (1) ◽  
pp. 45-48 ◽  
Author(s):  
E.A Irving ◽  
S.J Hadingham ◽  
J Roberts ◽  
M Gibbons ◽  
M Chabot-Fletcher ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cerebral Ischaemia ◽  
Nuclear Factor Κb ◽  
Binding Activity ◽  
Nuclear Factor ◽  
Focal Cerebral Ischaemia ◽  
Dna Binding Activity
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