Proteasome Inhibitors Induce Inhibitory κB (IκB) Kinase Activation, IκBα Degradation, and Nuclear Factor κB Activation in HT-29 Cells

2004 ◽  
Vol 65 (2) ◽  
pp. 342-349 ◽  
Author(s):  
Zoltán H. Németh ◽  
Hector R. Wong ◽  
Kelli Odoms ◽  
Edwin A. Deitch ◽  
Csaba Szabó ◽  
...  
2007 ◽  
Vol 35 (5) ◽  
pp. 1332-1340 ◽  
Author(s):  
Lee-Wei Chen ◽  
Pei-Hsuan Chen ◽  
Wei-Jung Chang ◽  
Jyh-Seng Wang ◽  
Michael Karin ◽  
...  

Blood ◽  
2009 ◽  
Vol 114 (5) ◽  
pp. 1046-1052 ◽  
Author(s):  
Teru Hideshima ◽  
Hiroshi Ikeda ◽  
Dharminder Chauhan ◽  
Yutaka Okawa ◽  
Noopur Raje ◽  
...  

Bortezomib is a proteasome inhibitor with remarkable preclinical and clinical antitumor activity in multiple myeloma (MM) patients. The initial rationale for its use in MM was inhibition of nuclear factor (NF)-κB activity by blocking proteasomal degradation of inhibitor of κBα (IκBα). Bortezomib inhibits inducible NF-κB activity; however, its impact on constitutive NF-κB activity in MM cells has not yet been defined. In this study, we demonstrate that bortezomib significantly down-regulated IκBα expression and triggered NF-κB activation in MM cell lines and primary tumor cells from MM patients. Importantly, no inhibition of p65 (RelA) nuclear translocation was recognized after bortezomib treatment in a murine xenograft model bearing human MM cells. Bortezomib-induced NF-κB activation was mediated via the canonical pathway. Moreover, other classes of proteasome inhibitors also induced IκBα down-regulation associated with NF-κB activation. Molecular mechanisms whereby bortezomib induced IκBα down-regulation were further examined. Bortezomib triggered phosphorylation of IκB kinase (IKKβ) and its upstream receptor-interacting protein 2, whereas IKKβ inhibitor MLN120B blocked bortezomib-induced IκBα down-regulation and NF-κB activation, indicating receptor-interacting protein 2/IKKβ signaling plays crucial role in bortezomib-induced NF-κB activation. Moreover, IKKβ inhibitors enhanced bortezomib-induced cytotoxicity. Our studies therefore suggest that bortezomib-induced cytotoxicity cannot be fully attributed to inhibition of canonical NF-κB activity in MM cells.


Endocrinology ◽  
2008 ◽  
Vol 149 (6) ◽  
pp. 3062-3066 ◽  
Author(s):  
Tayze T. Antunes ◽  
AnneMarie Gagnon ◽  
Melanie L. Langille ◽  
Alexander Sorisky

Our objective was to identify the signaling pathway activated by TSH that induces IL-6 secretion from human abdominal sc differentiated adipocytes. Human abdominal sc preadipocytes in culture were differentiated into adipocytes. IL-6 release stimulated by TSH was inhibited by 35% (P < 0.05) with SN50, an inhibitor of nuclear factor-κB (NF-κB) nuclear translocation, and 60% (P < 0.01) with sc-514, an inhibitor of inhibitory-κB (IκB) kinase (IKK)-β. Phosphorylation of IKKβ increased upon TSH treatment (10.3-fold, P < 0.01), and IκBα levels were reduced by 78% (P < 0.01). TSH activated NF-κB (23-fold, P < 0.001), a process that was inhibited (60%, P < 0.01) by SN50. Inhibition of protein kinase A by H89 did not affect TSH-stimulated IKKβ phosphorylation or IκBα degradation. TSH-mediated NF-κB activation and IL-6 induction also specifically occurred in Chinese hamster ovarian cells expressing the human TSH receptor, resulting in a 5.9-fold (P < 0.001) increase in IKKβ phosphorylation and a 9.5-fold increase in IL-6 mRNA expression. Our data demonstrate that the IKKβ/NF-κB pathway is a novel TSH target that is required for TSH-induced IL-6 release from human adipocytes.


Blood ◽  
2011 ◽  
Vol 117 (4) ◽  
pp. 1301-1307 ◽  
Author(s):  
Wei-Zhong Ying ◽  
Pei-Xuan Wang ◽  
Kristal J. Aaron ◽  
Kolitha Basnayake ◽  
Paul W. Sanders

Abstract One of the major attendant complications of multiple myeloma is renal injury, which contributes significantly to morbidity and mortality in this disease. Monoclonal immunoglobulin free light chains (FLCs) are usually directly involved, and tubulointerstitial renal injury and fibrosis are prominent histologic features observed in myeloma. The present study examined the role of monoclonal FLCs in altering the nuclear factor κ light chain enhancer of activated B cells (NF-κB) activity of renal epithelial cells. Human proximal tubule epithelial cells exposed to 3 different human monoclonal FLCs demonstrated Src kinase–dependent activation of the NF-κB pathway, which increased production of monocyte chemoattractant protein-1 (MCP-1). Tyrosine phosphorylation of inhibitor of κB kinases (IKKs) IKKα and IKKβ and a concomitant increase in inhibitor of κB (IκB) kinase activity in cell lysates were observed. Time-dependent, Src kinase–dependent increases in serine and tyrosine phosphorylation of IκBα and NF-κB activity were also demonstrated. Proteasome inhibition partially blocked FLC-induced MCP-1 production. These findings fit into a paradigm characterized by FLC-induced redox-signaling events that activated the canonical and atypical (IKK-independent) NF-κB pathways to promote a proinflammatory, profibrotic renal environment.


2005 ◽  
Vol 25 (10) ◽  
pp. 1301-1311 ◽  
Author(s):  
Yun S Song ◽  
Yong-Sun Lee ◽  
Pak H Chan

Nuclear factor-κB (NF-κB) has a central role in coordinating the expression of a wide variety of genes that control cerebral ischemia. Although there has been intense research on NF-κB, its mechanisms in the ischemic brain have not been clearly elucidated. We investigated the temporal profile of NF-κB-related genes using a complementary DNA array method in wild-type mice and human copper/zinc-superoxide dismutase transgenic (SOD1 Tg) mice that had low-level reactive oxygen species (ROS) by scavenging superoxide. Our DNA array showed that IκB kinase (IKK) complex (IKKα, β, and γ) mRNA in the wild-type mice was decreased as early as 1 h after reperfusion, after 30 mins of transient focal cerebral ischemia (tFCI). In contrast, tFCI in the SOD1 Tg mice caused an increase in the IKK complex. The IKK complex protein levels were also drastically decreased at 1 h in the wild-type mice, but did not change in the SOD1 Tg mice throughout the 7 days. Electrophoretic mobility shift assay revealed activation of NF-κB DNA binding after tFCI in the wild-type mice. Nuclear factor-κB activation occurred at the same time, as did the phosphorylation and degradation of the inhibitory protein κBα. However, SOD1 prevented NF-κB activation, and phosphorylation and degradation of IκBα after tFCI. Superoxide production and ubiquitinated protein in the SOD1 Tg mice were also lower than in the wild-type mice after tFCI. These results suggest that ROS are implicated in transient downregulation of IKKα, β, and γ in cerebral ischemia.


2018 ◽  
Vol 475 (22) ◽  
pp. 3595-3607 ◽  
Author(s):  
Anthony Fullam ◽  
Lili Gu ◽  
Yvette Höhn ◽  
Martina Schröder

DDX3 is a DEAD-box RNA helicase that we and others have previously implicated in antiviral immune signalling pathways leading to type I interferon (IFN) induction. We previously demonstrated that it directly interacts with the kinase IKKε (IκB kinase ε), enhances it activation, and then facilitates phosphorylation of the transcription factor IRF3 by IKKε. However, the TLR7/9 (Toll-like receptor 7/9)-mediated pathway, one of the most physiologically relevant IFN induction pathways, proceeds independently of IKKε or the related kinase TBK1 (TANK-binding kinase 1). This pathway induces type I IFN production via the kinases NIK (NF-κB-inducing kinase) and IKKα and is activated when plasmacytoid dendritic cells sense viral nucleic acids. In the present study, we demonstrate that DDX3 also directly interacts with IKKα and enhances its autophosphorylation and -activation. Modulation of DDX3 expression consequently affected NIK/IKKα-mediated IRF7 phosphorylation and induction of type I interferons. In addition, alternative NF-κB (nuclear factor-κB) activation, another pathway regulated by NIK and IKKα, was also down-regulated in DDX3 knockdown cells. This substantially broadens the effects of DDX3 in innate immune signalling to pathways beyond TBK1/IKKε and IFN induction. Dysregulation of these pathways is involved in disease states, and thus, our research might implicate DDX3 as a potential target for their therapeutic manipulation.


Author(s):  
Adeolu Alex Adedapo ◽  
Olusegun A Fagbohun ◽  
Christianah Dawurung ◽  
Ademola Adetokunbo Oyagbemi ◽  
Temidayo Olutayo Omobowale ◽  
...  

Abstract Background Pueraria tuberosa (Willd) D.C. (Fabaceae) tubers are already used in traditional medicine by Ayurvedic physicians for the management of fertility disorders, general weakness, and also as anti-ageing therapies. Other known pharmacological properties include: anti-hyperglycemics, hepatoprotective, anti-hyperlipidemic, diuretic, nutritive, and anti-fertility agents in male rats. Methods The anti-proliferative effect of the aqueous tuberous root extract of Pueraria tuberosa on vascular smooth muscle cells (VSMCs) and Human Colorectal Adenocarcinoma Cell lines (HT-29) was investigated using the Cell Titer 96 MTT Proliferation Assay where the viable cells were seeded at a density of 5 × 104 (100 µL/well). For VSMC, log concentrations of the extract at 200 and 800 µg/mL were added and incubated for 24 and 48 h time points. Incubation of the extract in the presence of vascular endothelial growth factor (VEGF) and ET-1 was also conducted at different times. Concentrations of the extract (200, 400 and 700 µg/mL) were also added and incubated with the HT 29 cell lines for 24, 48 and 72 h time points. The effect of the tuber aqueous extract of the plant on nuclear factor-κB (NF-κB) expression after 2 h was also carried out using immunoblotting technique. Results The result showed that after 24 h, the effect of the extract in the presence of the mitogens and on the VSMC was more of proliferation. However, at 48 h, the 200 µg/mL dose, both alone and in the presence of VEGF caused 11.1% and 25.9% decreases respectively, in cell proliferation. In the HT 29 cytotoxic study the 200 µg/mL concentration caused the greatest cytotoxic effect at 77.1% cell inhibition followed by 400 µg/mL concentration at 71.4% after 72 h. The immunoblotting assay showed a down regulation of NF-κB expressions with 0.7 µg/mL concentration showing the greatest effect. NF-κB, a pro-inflammatory agent is increasingly recognized as a crucial player in many steps of cancer initiation and progression. Conclusions It could therefore be concluded that the aqueous root extract of Pueraria tuberosa possesses cytotoxic effect and could serve as a lead compound for anticancer and anti-inflammatory agents.


2017 ◽  
Vol 95 (6) ◽  
pp. 763-767 ◽  
Author(s):  
Xin Lai ◽  
Mei Cao ◽  
Xu Song ◽  
Renyong Jia ◽  
Yuanfeng Zou ◽  
...  

Resveratrol, a natural compound found in over 70 plants, is known to possess immunoregulatory effects and anti-inflammatory activity. It has been shown that resveratrol has regulatory effects on different signaling pathways in different diseases. However, few reports have evaluated the effects of resveratrol on reinforcing immunity recovery via activating nuclear factor-κB (NF-κB) pathway and Jun N-terminal kinases (JNK) pathway. The present study aimed to assess immune-enhancing activity and underlying mechanism of resveratrol in immunosuppressive mice. Previously, we reported that resveratrol could promote mouse spleen lymphocyte functions to recover the immune system effectively. In the present study, we show that resveratrol could upregulate the expressions of NF-κB, IκB kinase, JNK, and c-jun in splenic lymphocytes of immunosuppressive mice. Taken together, our results indicate that resveratrol could promote recovery of immunologic function in immunosuppressive mice by activating JNK/NF-κB pathway.


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