scholarly journals Cellular senescence promotes endothelial activation through epigenetic alteration, and consequently accelerates atherosclerosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sakiko Honda ◽  
Koji Ikeda ◽  
Ryota Urata ◽  
Ekura Yamazaki ◽  
Noriaki Emoto ◽  
...  
Keyword(s):  
Cellular Senescence ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Atherosclerotic Lesion ◽  
Endothelial Activation ◽  
Dominant Negative ◽  
Epigenetic Alteration ◽  
Dominant Negative Form ◽  
Promising Therapeutic Target ◽  
Binding Factor

AbstractSenescent vascular cells are detected in atherosclerotic lesion, and its involvement in the development of atherosclerosis has been revealed; however, whether and the mechanism by which endothelial cell (EC) senescence is causally implicated in atherosclerosis remains unclear. We here investigate a role of EC senescence in atherosclerosis by utilizing EC-specific progeroid mice that overexpress the dominant negative form of telomeric repeat-binding factor 2 under the control of the Tie2 or vascular endothelial cadherin promoter. EC-specific progeria accelerated atherosclerosis in mice with target deletion of ApoE. Mechanistically, senescent ECs were markedly sensitive for inflammation-mediated VCAM-1 induction, leading to enhanced monocyte adhesion. Inhibition of NF-κB signaling abolished the enhanced inflammatory responses in senescent ECs, while NF-κB nuclear translocation in response to TNF-α were similar between young and senescent ECs. We found a higher association of VCAM-1 gene with active histone H3 trimethylated on lysine 4, leading to increased NF-κB accessibility in senescent ECs. Our data revealed that EC cellular senescence causes endothelial hyper-inflammability through epigenetic alteration, which consequently accelerates atherosclerosis. Therefore, EC senescence is a promising therapeutic target for the prevention and/or treatment of atherosclerotic disease in elderly population.

scholarly journals An Autocrine Wnt5a Loop Promotes NF-κB Pathway Activation and Cytokine/Chemokine Secretion in Melanoma

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1060 ◽  
Author(s):  
Gastón Barbero ◽  
María Victoria Castro ◽  
María Belén Villanueva ◽  
María Josefina Quezada ◽  
Natalia Brenda Fernández ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Epithelial Mesenchymal Transition ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Melanoma Cells ◽  
Dominant Negative ◽  
Migration And Invasion ◽  
Soluble Receptor ◽  
Mesenchymal Transition ◽  
Cytokines And Chemokines

Wnt5a signaling has been implicated in the progression of cancer by regulating multiple cellular processes, largely migration and invasion, epithelial-mesenchymal transition (EMT), and metastasis. Since Wnt5a signaling has also been involved in inflammatory processes in infectious and inflammatory diseases, we addressed the role of Wnt5a in regulating NF-κB, a pivotal mediator of inflammatory responses, in the context of cancer. The treatment of melanoma cells with Wnt5a induced phosphorylation of the NF-κB subunit p65 as well as IKK phosphorylation and IκB degradation. By using cDNA overexpression, RNA interference, and dominant negative mutants we determined that ROR1, Dvl2, and Akt (from the Wnt5a pathway) and TRAF2 and RIP (from the NF-κB pathway) are required for the Wnt5a/NF-κB crosstalk. Wnt5a also induced p65 nuclear translocation and increased NF-κB activity as evidenced by reporter assays and a NF-κB-specific upregulation of RelB, Bcl-2, and Cyclin D1. Further, stimulation of melanoma cells with Wnt5a increased the secretion of cytokines and chemokines, including IL-6, IL-8, IL-11, and IL-6 soluble receptor, MCP-1, and TNF soluble receptor I. The inhibition of endogenous Wnt5a demonstrated that an autocrine Wnt5a loop is a major regulator of the NF-κB pathway in melanoma. Taken together, these results indicate that Wnt5a activates the NF-κB pathway and has an immunomodulatory effect on melanoma through the secretion of cytokines and chemokines.

Cytoplasmic PML Function in TGF-β Signaling.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 481-481
Author(s):  
Hui-Kuan Lin ◽  
Stephan Bergmann ◽  
Pier Paolo Pandolfi
Keyword(s):  
Cellular Senescence ◽  
Target Genes ◽  
Nuclear Translocation ◽  
Receptor Activation ◽  
Nuclear Body ◽  
Dominant Negative ◽  
Cancer Pathogenesis ◽  
Smad3 Phosphorylation ◽  
Dependent Growth ◽  
Β Function

Abstract TGF-β is a pluripotent cytokine that controls key tumor suppressive functions such as cell growth inhibition, induction of apoptosis, cellular senescence and differentiation. Cancer cells are often unresponsive to TGF-β. Blasts from several leukemia subtypes including acute promyelocytic leukemia (APL) display resistance to TGF-β-growth inhibitory and differentiating activity. As TGF-β, the PML tumor suppressor of APL is also known to modulate key tumor suppressive functions. PML is found to accumulate in the PML-nuclear body, although cytoplasmic isoforms of unknown function have also been described. The PML-RARα fusion oncoprotein of APL is found to accumulate both in the nucleus and cytoplasm and is thought to act as a dominant negative PML mutant in view of its ability to heterodimerize with PML. Given the functional similarities between PML and TGF-β and their functional loss in APL, we asked whether PML would modulate TGF-β function. Here we show that cytoplasmic Pml is an essential modulator of TGF-β signaling. Pml-null primary cells of diverse histological origins are resistant to TGF-β-dependent growth arrest, induction of cellular senescence and apoptosis. Induction of TGF-β target genes such as p21 and p15, as well as Smad2 and Smad3 phosphorylation and nuclear translocation is also dramatically impaired in the absence of Pml. Cytoplasmic Pml is induced by TGF-β and its add-back to Pml-null cells can fully rescue these biological and biochemical defects. Furthermore, we find that cytoplasmic PML physically interacts with Smad2/3 and SARA (Smad anchor for receptor activation), colocalizes with these proteins in cytosolic regions and is required for association of Smad2/3 with SARA and for the accumulation of SARA and TGF-β receptor in the early endosome. We demonstrate that the PML-RARα oncoprotein of APL can antagonize cytoplasmic PML function and that APL blasts display defects in TGF-β signaling similar to that observed in Pml-null cells, which can be overcome by retinoic acid (RA) and As2O3, drugs that induce PML-RARα degradation and are effective in APL treatment. Our findings identify cytoplasmic PML as a critical TGF-β regulator, and further implicate deregulated TGF-β signaling in cancer pathogenesis.

Regulation of IKKe expression by androgen receptor and NF-kB transcriptional factor in prostate cancer

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 10106-10106
Author(s):  
B. Péant ◽  
J. Diallo ◽  
L. Lessard ◽  
A. Mes-Masson ◽  
F. Saad
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cell Lines ◽  
Nuclear Translocation ◽  
Dominant Negative ◽  
Lncap Cells ◽  
Dominant Negative Form ◽  
Androgen Resistance ◽  
Dependent Cell ◽  
Hormone Refractory

10106 Background: In unstimulated cells, NF-kB transcription factor is sequestered in the cytoplasm as an inactive p65/p50 dimer through interaction with a member of the inhibitor of kB protein family (IkBa). Prominent constitutive activation of NF-kB was observed in prostate cancer (PCa) cell lines lacking androgen receptor (AR) expression (PC3 and DU145) whereas only very low levels of NF-kB activity were seen in androgen-dependent cell lines (LNCaP and CWR22Rv1). As IkB kinase-e (IKKe) has recently been shown to be controlled by NF-kB, we hypothesize that IKKe may be involved in PCa progression based on its interaction with the NF-kB protein, and that these interactions are influenced by AR signaling. Methods: LNCaP cells were used to study IKKe expression with or without stimulation by the analog of androgen R1881 and by the tumor necrosis factor (TNF)-a. IKKe protein and RNA expression were characterized by immunoblot assay and quantitative PCR, respectively. IKKe expression was then correlated with p65 nuclear localisation. NF-kB activity was inhibited using an IkBa dominant negative construction. Inhibition of AR synthesis was performed using a siRNA against AR. Results: IKKe gene expression was stimulated by TNF-a treatment in LNCaP cells and inhibited by transfection of a dominant negative form of IkBa which prevented the nuclear translocation of p65. We also observed constitutive IKKe expression in hormone-refractory cells. Furthermore, we showed that TNF-a-induced IKKe expression is inhibited by R1881 in hormone-responsive PCa cells and this inhibition was correlated with the modulation of IkBa expression by R1881. Finally, we observed that the expression of IKKe is constitutively induced after blocking AR expression in LNCaP cells. Conclusions:. Our results show that IKKe expression is regulated by NF-kB in PCa cell lines. Moreover, IKKe appears to be down-regulated by ligand-dependent AR signaling through the control of IkBa expression. Further studies will be needed in order to determine the implications of this phenomenon with regard to NF-kB regulation, androgen resistance and effect on PCa progression. No significant financial relationships to disclose.

MASK, a large ankyrin repeat and KH domain-containing protein involved inDrosophilareceptor tyrosine kinase signaling

Development ◽  
2002 ◽  
Vol 129 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Rachel K. Smith ◽  
Pamela M. Carroll ◽  
John D. Allard ◽  
Michael A. Simon
Keyword(s):  
Signaling Pathways ◽  
Tyrosine Kinases ◽  
Nuclear Translocation ◽  
Tyrosine Phosphatase ◽  
Growth Factor Receptor ◽  
Dominant Negative ◽  
Common Component ◽  
Rtk Signaling ◽  
Dominant Negative Form ◽  
Kh Domain

The receptor tyrosine kinases Sevenless (SEV) and the Epidermal growth factor receptor (EGFR) are required for the proper development of the Drosophila eye. The protein tyrosine phosphatase Corkscrew (CSW) is a common component of many RTK signaling pathways, and is required for signaling downstream of SEV and EGFR. In order to identify additional components of these signaling pathways, mutations that enhanced the phenotype of a dominant negative form of Corkscrew were isolated. This genetic screen identified the novel signaling molecule MASK, a large protein that contains two blocks of ankyrin repeats as well as a KH domain. MASK genetically interacts with known components of these RTK signaling pathways. In the developing eye imaginal disc, loss of MASK function generates phenotypes similar to those generated by loss of other components of the SEV and EGFR pathways. These phenotypes include compromised photoreceptor differentiation, cell survival and proliferation. Although MASK is localized predominantly in the cellular cytoplasm, it is not absolutely required for MAPK activation or nuclear translocation. Based on our results, we propose that MASK is a novel mediator of RTK signaling, and may act either downstream of MAPK or transduce signaling through a parallel branch of the RTK pathway.

scholarly journals Inhibition of Nuclear Import by the Proapoptotic Protein CC3

2004 ◽  
Vol 24 (16) ◽  
pp. 7091-7101 ◽  
Author(s):  
Frank W. King ◽  
Emma Shtivelman
Keyword(s):  
Nuclear Import ◽  
Nuclear Translocation ◽  
Cellular Protein ◽  
Dominant Negative ◽  
Transport Pathways ◽  
Proapoptotic Protein ◽  
Dominant Negative Form ◽  
Increased Sensitivity

ABSTRACT We report here that the normal cellular protein CC3/TIP30, when in excess, inhibits nuclear import in vitro and in vivo. CC3 binds directly to the karyopherins of the importin β family in a RanGTP-insensitive manner and associates with nucleoporins in vivo. CC3 inhibits the nuclear import of proteins possessing either the classical nuclear localization signal or the M9 signal recognized by transportin. CC3 also inhibits nuclear translocation of transportin itself. Cells modified to express higher levels of CC3 have a slower rate of nuclear import and, as described earlier, show an increased sensitivity to death signals. A mutant CC3 protein lacking proapoptotic activity has a lower affinity for transportin, is displaced from it by RanGTP, and fails to inhibit nuclear import in vitro and in vivo. Together, our results support a correlation between the ability of CC3 to form a RanGTP-resistant complex with importins, inhibit nuclear import, and induce apoptosis. Significantly, a dominant-negative form of importin β1 shown previously to inhibit multiple transport pathways induces rapid cell death, strongly indicating that inhibition of nuclear transport serves as a potent apoptotic signal.

scholarly journals Dendranthema zawadskii var. lucidum (Nakai) J.H. Park Extract Inhibits Cellular Senescence in Human Dermal Fibroblasts and Aging-Related Inflammation in Rats

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 801
Author(s):  
Jehun Choi ◽  
Gwi-Yeong Jang ◽  
Jeonghoon Lee ◽  
Hae-Young Chung ◽  
Hyung-Jun Noh ◽  
...  
Keyword(s):  
Cellular Senescence ◽  
Cell Cycle Progression ◽  
Inflammatory Responses ◽  
Dermal Fibroblast ◽  
Dermal Fibroblasts ◽  
Dependent Manner ◽  
Aged Rats ◽  
Age Related ◽  
Dendranthema Zawadskii ◽  
Beta Galactosidase

Senescence is the phenomenon by which physiological functions of organisms degenerate with time. Cellular senescence is marked by an inhibition of cell cycle progression. Beta-galactosidase accumulates in the lysosomes of aged cells. In this study, human dermal fibroblast cells (HDFs) were treated with 0.5 μM doxorubicin for 4 h to induce cellular senescence. Senescence-associated beta-galactosidase (SA-β-gal) activity was then measured 72 h after treatment with aerial parts of Dendranthema zawadskii var. lucidum (Nakai) J.H. Park (DZ) extract. Treatment with DZ extract significantly decreased SA-β-gal activity in a dose-dependent manner in HDFs. Additionally, DZ extract treatment reduced age-related oxidative stress and inflammation in the aortas of aged rats. The reactive oxygen species (ROS) levels in aortas of aged control rats were higher than those in young rats. However, DZ extract-fed aged rats showed significantly lower ROS levels than the aged control rats. When the aged rats were treated with DZ extract at either 0.2 or 1.0 mg∙kg−1∙day−1, NF-κB levels in aorta tissue decreased significantly compared to those in aorta tissue of the aged control rats without DZ treatment. In addition, DZ extract-fed aged rat aortas showed significant reductions in expression of iNOS and COX-2 induced by NF-κB translocation. Therefore, these results suggest that DZ effectively inhibited senescence-related NF-κB activation and inflammation. DZ extract may have a role in the prevention of the vascular inflammatory responses that occur during vascular aging.

scholarly journals Transcriptional Regulators of theSchizosaccharomyces pombe fbp1Gene Include Two Redundant Tup1p-like Corepressors and the CCAAT Binding Factor Activation Complex

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1205-1215 ◽  
Author(s):  
Rozmin T K Janoo ◽  
Lori A Neely ◽  
Burkhard R Braun ◽  
Simon K Whitehall ◽  
Charles S Hoffman
Keyword(s):  
Protein Kinase ◽  
Fold Increase ◽  
Transcriptional Regulators ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Lacz Expression ◽  
Protein Subunit ◽  
Plasmid Library ◽  
Binding Factor ◽  
Mitogen Activated Protein

AbstractThe Schizosaccharomyces pombe fbp1 gene, which encodes fructose-1,6-bis-phosphatase, is transcriptionally repressed by glucose through the activation of the cAMP-dependent protein kinase A (PKA) and transcriptionally activated by glucose starvation through the activation of a mitogen-activated protein kinase (MAPK). To identify transcriptional regulators acting downstream from or in parallel to PKA, we screened an adh-driven cDNA plasmid library for genes that increase fbp1 transcription in a strain with elevated PKA activity. Two such clones express amino-terminally truncated forms of the S. pombe tup12 protein that resembles the Saccharomyces cerevisiae Tup1p global corepressor. These clones appear to act as dominant negative alleles. Deletion of both tup12 and the closely related tup11 gene causes a 100-fold increase in fbp1-lacZ expression, indicating that tup11 and tup12 are redundant negative regulators of fbp1 transcription. In strains lacking tup11 and tup12, the atf1-pcr1 transcriptional activator continues to play a central role in fbp1-lacZ expression; however, spc1 MAPK phosphorylation of atf1 is no longer essential for its activation. We discuss possible models for the role of tup11- and tup12-mediated repression with respect to signaling from the MAPK and PKA pathways. A third clone identified in our screen expresses the php5 protein subunit of the CCAAT-binding factor (CBF). Deletion of php5 reduces fbp1 expression under both repressed and derepressed conditions. The CBF appears to act in parallel to atf1-pcr1, although it is unclear whether or not CBF activity is regulated by PKA.

scholarly journals Intestinal Apolipoprotein A-IV Gene Transcription Is Controlled by Two Hormone-Responsive Elements: A Role for Hepatic Nuclear Factor-4 Isoforms

2005 ◽  
Vol 19 (9) ◽  
pp. 2320-2334 ◽  
Author(s):  
Amena Archer ◽  
Dominique Sauvaget ◽  
Valérie Chauffeton ◽  
Pierre-Etienne Bouchet ◽  
Jean Chambaz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Distal Region ◽  
Proximal Region ◽  
Dominant Negative ◽  
Specific Expression ◽  
Nuclear Factors ◽  
Dominant Negative Form ◽  
Responsive Element ◽  
Hormone Responsive Element

Abstract In the small intestine, the expression of the apolipoprotein (apo) C-III and A-IV genes is restricted to the enterocytes of the villi. We have previously shown that, in transgenic mice, specific expression of the human apo C-III requires a hormone-responsive element (HRE) located in the distal region of the human apoA-IV promoter. This HRE binds the hepatic nuclear factors (HNF)-4α and γ. Here, intraduodenal injections in mice and infections of human enterocytic Caco-2/TC7 cells with an adenovirus expressing a dominant-negative form of HNF-4α repress the expression of the apoA-IV gene, demonstrating that HNF-4 controls the apoA-IV gene expression in enterocytes. We show that HNF-4α and γ functionally interact with a second HRE present in the proximal region of the human apoA-IV promoter. New sets of transgenic mice expressing mutated forms of the promoter, combined with the human apo C-III enhancer, demonstrate that, whereas a single HRE is sufficient to reproduce the physiological cephalo-caudal gradient of apoA-IV gene expression, both HREs are required for expression that is restricted to villi. The combination of multiple HREs may specifically recruit regulatory complexes associating HNF-4 and either coactivators in villi or corepressors in crypts.

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