scholarly journals Transcriptional Networks and Cellular Senescence in Human Mammary Fibroblasts

2005 ◽  
Vol 16 (2) ◽  
pp. 943-953 ◽  
Author(s):  
K. Hardy ◽  
L. Mansfield ◽  
A. Mackay ◽  
S. Benvenuti ◽  
S. Ismail ◽  
...  
Keyword(s):  
Cellular Senescence ◽  
In Silico ◽  
Promoter Analysis ◽  
Replicative Senescence ◽  
Nuclear Factor Κb ◽  
The Body ◽  
Transcriptional Networks ◽  
Proliferative Potential ◽  
Mobility Shift ◽  
Mobility Shift Assay

Senescence, the molecular program that limits the finite proliferative potential of a cell, acts as an important barrier to protect the body from cancer. Techniques for measuring transcriptome changes and for modulating their expression suggest that it may be possible to dissect the transcriptional networks underlying complex cellular processes. HMF3A cells are conditionally immortalized human mammary fibroblasts that can be induced to undergo coordinated senescence. Here, we used these cells in conjunction with microarrays, RNA interference, and in silico promoter analysis to promote the dissection of the transcriptional networks responsible for regulating cellular senescence. We first identified changes in the transcriptome when HMF3A cells undergo senescence and then compared them with those observed upon replicative senescence in primary human mammary fibroblasts. In addition to DUSP1 and known p53 and E2F targets, a number of genes such as PHLDA1, NR4A3, and a novel splice variant of STAC were implicated in senescence. Their role in senescence was then analyzed by RNA silencing followed by microarray analysis. In silico promoter analysis of all differential genes predicted that nuclear factor-κB and C/EBP transcription factors are activated upon senescence, and we confirmed this by electrophoretic mobility shift assay. The results suggest a putative signaling network for cellular senescence.

scholarly journals Identification of a Selective RelA Inhibitor Based on DSE-FRET Screening Methods

2020 ◽  
Vol 21 (23) ◽  
pp. 9150
Author(s):  
Yoshitomo Shiroma ◽  
Go Fujita ◽  
Takuya Yamamoto ◽  
Ryou-u Takahashi ◽  
Ashutosh Kumar ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Nuclear Factor Κb ◽  
Screening Methods ◽  
Biological Functions ◽  
Mobility Shift ◽  
Dna Strand Exchange ◽  
Mobility Shift Assay ◽  
Dna Strand

Nuclear factor-κB (NF-κB) is an important transcription factor involved in various biological functions, including tumorigenesis. Hence, NF-κB has attracted attention as a target factor for cancer treatment, leading to the development of several inhibitors. However, existing NF-κB inhibitors do not discriminate between its subunits, namely, RelA, RelB, cRel, p50, and p52. Conventional methods used to evaluate interactions between transcription factors and DNA, such as electrophoretic mobility shift assay and luciferase assays, are unsuitable for high-throughput screening (HTS) and cannot distinguish NF-κB subunits. We developed a HTS method named DNA strand exchange fluorescence resonance energy transfer (DSE-FRET). This assay is suitable for HTS and can discriminate a NF-κB subunit. Using DSE-FRET, we searched for RelA-specific inhibitors and verified RelA inhibition for 32,955 compounds. The compound A55 (2-(3-carbamoyl-6-hydroxy-4-methyl-2-oxopyridin-1(2H)-yl) acetic acid) selectively inhibited RelA–DNA binding. We propose that A55 is a seed compound for RelA-specific inhibition and could be used in clinical applications.

IL-1β induces eotaxin gene transcription in A549 airway epithelial cells through NF-κB

2000 ◽  
Vol 279 (6) ◽  
pp. L1058-L1065 ◽  
Author(s):  
Sean Jedrzkiewicz ◽  
Hidetoshi Nakamura ◽  
Eric S. Silverman ◽  
Andrew D. Luster ◽  
Naresh Mansharamani ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Transcriptional Activation ◽  
Transcriptional Start Site ◽  
Nuclear Factor Κb ◽  
Airway Epithelial Cells ◽  
Site Directed Mutagenesis ◽  
Airway Epithelial ◽  
Mobility Shift ◽  
Mobility Shift Assay ◽  
Necessary And Sufficient

Eotaxin is an asthma-related C-C chemokine that is produced in response to interleukin-1β (IL-1β). We detected an increase in newly transcribed eotaxin mRNA in IL-1β-stimulated airway epithelial cells. Transient transfection assays using promoter-reporter constructs identified a region as essential for IL-1β-induced increases in eotaxin transcription. Using site-directed mutagenesis, we found that a nuclear factor-κB (NF-κB) site located 46 bp upstream from the transcriptional start site was both necessary and sufficient for IL-1β induction of reporter construct activity. Electrophoretic mobility shift assay demonstrated that IL-1β-stimulated airway epithelial cells produced p50 and p65 protein that bound this site in a sequence-specific manner. The functional importance of the NF-κB site was demonstrated by coexpression experiments in which increasing doses of p65 expression vector were directly associated with reporter activity exclusively in constructs with an intact NF-κB site ( r 2 = 0.97, P = 0.002). Moreover, IL-1β-induced increases in eotaxin mRNA expression are inhibited by inhibitors of NF-κB. Our findings implicate NF-κB and its binding sequence in IL-1β-induced transcriptional activation of the eotaxin gene.

scholarly journals Cyclolinteinone, a sesterterpene from sponge Cacospongia linteiformis, prevents inducible nitric oxide synthase and inducible cyclo-oxygenase protein expression by blocking nuclear factor-κB activation in J774 macrophages

2000 ◽  
Vol 346 (3) ◽  
pp. 793-798 ◽  
Author(s):  
Fulvio D'ACQUISTO ◽  
Virginia LANZOTTI ◽  
Rosa CARNUCCIO
Keyword(s):  
Nitric Oxide ◽  
Protein Expression ◽  
Nuclear Translocation ◽  
Inflammatory Diseases ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
J774 Cells ◽  
Cox 2 ◽  
Mobility Shift Assay

We investigated the effect of cyclolinteinone, a sesterterpene from Caribbean sponge Cacospongia linteiformis, on inducible NO synthase (iNOS) and cyclo-oxygenase-2 (COX-2) protein expression in lipopolysaccharide (LPS)-stimulated J774 macrophages. Incubation of J774 cells with LPS (1 μg/ml) caused an increase of both iNOS and COX-2 protein expression, which was prevented in a concentration-dependent fashion by cyclolinteinone (12.5, 25 and 50 μM). Electrophoretic mobility-shift assay indicated that cyclolinteinone blocked the activation of nuclear factor-ĸB (NF-ĸB), a transcription factor necessary for either iNOS or COX-2 induction. Cyclolinteinone also blocked disappearance of IĸB-α from cytosolic fraction and nuclear translocation of NF-ĸB subunits p50 and p65. These results show that cyclolinteinone down-regulates iNOS and COX-2 protein expression by inhibiting NF-ĸB activation and suggest that it may represent a novel anti-inflammatory compound capable of controlling the excessive production of prostaglandins and nitric oxide occurring in several inflammatory diseases.

scholarly journals Cellular Senescence Triggers Altered Circadian Clocks With a Prolonged Period and Delayed Phases

2021 ◽  
Vol 15 ◽  
Author(s):  
Rezwana Ahmed ◽  
Yasukazu Nakahata ◽  
Kazuyuki Shinohara ◽  
Yasumasa Bessho
Keyword(s):  
Oxidative Stress ◽  
Circadian Clock ◽  
Cellular Senescence ◽  
Replicative Senescence ◽  
The Body ◽  
Premature Senescence ◽  
High Metabolic Rate ◽  
Gene Expressions ◽  
Altered Gene ◽  
Stress Induced Premature Senescence

Senescent cells, which show the permanent growth arrest in response to various forms of stress, accumulate in the body with the progression of age, and are associated with aging and age-associated diseases. Although the senescent cells are growth arrested, they still demonstrate high metabolic rate and altered gene expressions, indicating that senescent cells are still active. We recently showed that the circadian clock properties, namely phase and period of the cells, are altered with the establishment of replicative senescence. However, whether cellular senescence triggers the alteration of circadian clock properties in the cells is still unknown. In this study we show that the oxidative stress-induced premature senescence induces the alterations of the circadian clock, similar to the phenotypes of the replicative senescent cells. We found that the oxidative stress-induced premature senescent cells display the prolonged period and delayed phases. In addition, the magnitude of these changes intensified over time, indicating that cellular senescence changes the circadian clock properties. Our current results corroborate with our previous findings and further confirm that cellular senescence induces altered circadian clock properties, irrespective of the replicative senescence or the stress-induced premature senescence.

Role of NF-κB in TNF-α-induced COX-2 Expression in Synovial Fibroblasts from Human TMJ

2007 ◽  
Vol 86 (4) ◽  
pp. 363-367 ◽  
Author(s):  
J. Ke ◽  
X. Long ◽  
Y. Liu ◽  
Y.F. Zhang ◽  
J. Li ◽  
...  
Keyword(s):  
Synovial Fibroblasts ◽  
Nuclear Factor Κb ◽  
Mobility Shift ◽  
Tnf Α ◽  
Cox 2 ◽  
Mobility Shift Assay ◽  
Pre Treatment ◽  
Factor Α ◽  
Necrosis Factor

In the temporomandibular joint (TMJ) synovium, cyclo-oxygenase-2 (COX-2) expression has been believed to be directly related to joint pain and synovitis. Here we investigated the role of Nuclear Factor κB (NF-κB) in the regulation of COX-2 expression in synovial fibroblasts from human TMJ induced by tumor necrosis factor-α (TNF-α). By reverse-transcriptase/polymerase chain-reaction (RT-PCR) and Western blotting analysis, TNF-α induced a dose- and time-dependent increase in COX-2 expression. Electrophoretic mobility shift assay (EMSA) revealed that transient NF-κB activation in the COX-2 promoter was triggered by TNF-α. In parallel with transient NF-κB activation, the rapid translocation of NF-κB, particularly the p65 subunit, from the cytoplasm into the nucleus was demonstrated. Pre-treatment with pyrolidine dithiocarbamate (PDTC), one of the NF-κB inhibitors, prevented binding to the COX-2 promoter and expression of COX-2 protein in response to TNF-α. These findings indicate that activation of NF-κB is responsible for TNF-α-induced COX-2 expression in synovial fibroblasts from the TMJ.

Inhibition of the nuclear factor—κB activation with pyrrolidine dithiocarbamate attenuating inflammation and oxidative stress after experimental spinal cord trauma in rats

2004 ◽  
Vol 1 (3) ◽  
pp. 311-321 ◽  
Author(s):  
Giovanni La Rosa ◽  
Salvatore Cardali ◽  
Tiziana Genovese ◽  
Alfredo Conti ◽  
Rosanna Di Paola ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Nuclear Factor Κb ◽  
Pyrrolidine Dithiocarbamate ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
Content Type ◽  
Cord Injury ◽  
Mobility Shift Assay ◽  
And Oxidative Stress ◽  
Fine Print

Object. The nuclear factor—κB (NF-κB) is a transcription factor that plays a pivotal role in the induction of genes involved in physiological processes and in the response to inflammation. The authors of recent studies have demonstrated that NF-κB and oxidative stress contribute to secondary injury after impact-induced spinal cord injury (SCI) in the rat. Dithiocarbamates are antioxidants that are potent inhibitors of NF-κB. The authors postulated that pyrrolidine dithiocarbamate (PDTC) would attenuate NF-κB—related inflammatory and oxidative events that occur after SCI. Methods. Spinal cord injury was induced by the application of vascular clips (force of 50 g) to the dura mater after a four-level T5–8 laminectomy. The authors investigated the effects of PDTC (30 mg/kg administered 30 minutes before SCI and 6 hours after SCI) on the development of the inflammatory response associated with SCI in rats. Levels of myeloperoxidase activity were measured as an indicator of polymorphonuclear infiltration; malondialdehyde levels in the spinal cord tissue were determined as an indicator of lipid peroxidation. The following studies were performed: immunohistochemical analysis to assess levels of inducible nitric oxide synthase (iNOS), nitrotyrosine formation, poly([adenosine diphosphate]-ribose) polymerase (PARP) activity; Western blot analysis to determine cytoplasmic levels of inhibitory—κB-α (IκB-α); and electrophoretic mobility-shift assay to measure the level of DNA/NF-κB binding. The PDTC treatment exerted potent antiinflammatory effects with significant reduction of polymorphonuclear cell infiltration, lipid peroxidation, and iNOS activity. Furthermore, administration of PDTC reduced immunohistochemical evidence of formation of nitrotyrosine and PARP activation in the spinal cord section obtained in the SCI-treated rats. Additionally, PDTC treatment significantly prevented the activation of NF-κB (electrophoretic mobility-shift assay and immunoblot analysis). Conclusions. Overall, the results clearly demonstrate that PDTC-related prevention of the activation of NF-κB reduces the development of some secondary injury events after SCI. Therefore, inhibition of NF-κB may represent a novel approach in the treatment of SCIs.

Transcriptional regulation mechanisms of hypoxia-induced neuroglobin gene expression

2012 ◽  
Vol 443 (1) ◽  
pp. 153-164 ◽  
Author(s):  
Ning Liu ◽  
Zhanyang Yu ◽  
Shuanglin Xiang ◽  
Song Zhao ◽  
Anna Tjärnlund-Wolf ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hypoxia Inducible Factor ◽  
Gene Promoter ◽  
Nuclear Factor Κb ◽  
Proximal Promoter ◽  
Mobility Shift ◽  
Hypoxic Conditions ◽  
Mobility Shift Assay

Ngb (neuroglobin) has been identified as a novel endogenous neuroprotectant. However, little is known about the regulatory mechanisms of Ngb expression, especially under conditions of hypoxia. In the present study, we located the core proximal promoter of the mouse Ngb gene to a 554 bp segment, which harbours putative conserved NF-κB (nuclear factor κB)- and Egr1 (early growth-response factor 1) -binding sites. Overexpression and knockdown of transcription factors p65, p50, Egr1 or Sp1 (specificity protein 1) increased and decreased Ngb expression respectively. Experimental assessments with transfections of mutational Ngb gene promoter constructs, as well as EMSA (electrophoretic mobility-shift assay) and ChIP (chromatin immunoprecipitation) assays, demonstrated that NF-κB family members (p65, p50 and cRel), Egr1 and Sp1 bound in vitro and in vivo to the proximal promoter region of the Ngb gene. Moreover, a κB3 site was found as a pivotal cis-element responsible for hypoxia-induced Ngb promoter activity. NF-κB (p65) and Sp1 were also responsible for hypoxia-induced up-regulation of Ngb expression. Although there are no conserved HREs (hypoxia-response elements) in the promoter of the mouse Ngb gene, the results of the present study suggest that HIF-1α (hypoxia-inducible factor-1α) is also involved in hypoxia-induced Ngb up-regulation. In conclusion, we have identified that NF-κB, Egr1 and Sp1 played important roles in the regulation of basal Ngb expression via specific interactions with the mouse Ngb promoter. NF-κB, Sp1 and HIF-1α contributed to the up-regulation of mouse Ngb gene expression under hypoxic conditions.

scholarly journals Interleukin-10-mediated inhibition of free radical generation in macrophages

2001 ◽  
Vol 280 (6) ◽  
pp. L1196-L1202 ◽  
Author(s):  
Sujatha Dokka ◽  
Xianglin Shi ◽  
Stephen Leonard ◽  
Liying Wang ◽  
Vincent Castranova ◽  
...  
Keyword(s):  
Gene Transfection ◽  
Sodium Formate ◽  
Nuclear Factor Κb ◽  
Interleukin 10 ◽  
Oh Radicals ◽  
Mobility Shift ◽  
Inflammatory Processes ◽  
Mobility Shift Assay ◽  
Metal Catalyzed

Interleukin-10 (IL-10) is a pleiotropic cytokine that controls inflammatory processes by suppressing the production of proinflammatory cytokines that are known to be transcriptionally regulated by nuclear factor-κB (NF-κB). Although still controversial, IL-10 has been shown to inhibit NF-κB activation through a process that involves proteolytic degradation of inhibitory subunit IκB-α. What is not known, however, is the mechanism by which IL-10 exerts its effect on IκB-α degradation. The present study investigates the possible role of reactive oxygen species (ROS) and their inhibition by IL-10 in NF-κB activation and IκB-α degradation in macrophages. Treatment of the cells with lipopolysaccharide (LPS) caused activation of NF-κB and rapid proteolysis of IκB-α as determined by the electrophoretic mobility shift assay, gene transfection, and Western blot. IL-10 pretreatment inhibited both NF-κB activation and IκB-α degradation. Both of these processes were also inhibited by ROS scavengers, catalase (H2O2 scavenger), and sodium formate (·OH scavenger) but were minimally affected by superoxide dismutase (O[Formula: see text] scavenger). These results suggests that ·OH radicals, formed by an H2O2-dependent, metal-catalyzed Fenton reaction, play a major role in this process. Electron spin resonance studies confirmed the formation of ·OH radicals in LPS-treated cells. Addition of IL-10 inhibited both IκB-α degradation and generation of ·OH radicals in response to LPS stimulation. These results demonstrate, for the first time, direct evidence for the role of IL-10 in ROS-dependent NF-κB activation.

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