p85α Acts as a Novel Signal Transducer for Mediation of Cellular Apoptotic Response to UV Radiation

Lun Song; Jingxia Li; Jianping Ye; Gang Yu; Jin Ding; Dongyun Zhang; Weiming Ouyang; Zigang Dong; Sung O. Kim; Chuanshu Huang

doi:10.1128/mcb.00657-06

p85α Acts as a Novel Signal Transducer for Mediation of Cellular Apoptotic Response to UV Radiation

Molecular and Cellular Biology ◽

10.1128/mcb.00657-06 ◽

2007 ◽

Vol 27 (7) ◽

pp. 2713-2731 ◽

Cited By ~ 29

Author(s):

Lun Song ◽

Jingxia Li ◽

Jianping Ye ◽

Gang Yu ◽

Jin Ding ◽

...

Keyword(s):

Signaling Pathway ◽

Uv Radiation ◽

Gene Transcription ◽

Cell Apoptosis ◽

Cellular Response ◽

Nuclear Translocation ◽

Site Directed Mutagenesis ◽

Regulatory Subunit ◽

Special Effect ◽

Tnf Α

ABSTRACT Apoptosis is an important cellular response to UV radiation (UVR), but the corresponding mechanisms remain largely unknown. Here we report that the p85α regulatory subunit of phosphatidylinositol 3-kinase (PI-3K) exerted a proapoptotic role in response to UVR through the induction of tumor necrosis factor alpha (TNF-α) gene expression. This special effect of p85α was unrelated to the PI-3K-dependent signaling pathway. Further evidence demonstrated that the inducible transcription factor NFAT3 was the major downstream target of p85α for the mediation of UVR-induced apoptosis and TNF-α gene transcription. p85α regulated UVR-induced NFAT3 activation by modulation of its nuclear translocation and DNA binding and the relevant transcriptional activities. Gel shift assays and site-directed mutagenesis allowed the identification of two regions in the TNF-α gene promoter that served as the NFAT3 recognition sequences. Chromatin immunoprecipitation assays further confirmed that the recruitment of NFAT3 to the endogenous TNF-α promoter was regulated by p85α upon UVR exposure. Finally, the knockdown of the NFAT3 level by its specific small interfering RNA decreased UVR-induced TNF-α gene transcription and cell apoptosis. The knockdown of endogenous p85α blocked NFAT activity and TNF-α gene transcription, as well as cell apoptosis. Thus, we demonstrated p85α-associated but PI-3K-independent cell death in response to UVR and identified a novel p85α/NFAT3/TNF-α signaling pathway for the mediation of cellular apoptotic responses under certain stress conditions such as UVR.

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A Novel Inhibitor of the NF-κB Signaling Pathway Encoded by the Parapoxvirus Orf Virus

Journal of Virology ◽

10.1128/jvi.02291-09 ◽

2010 ◽

Vol 84 (8) ◽

pp. 3962-3973 ◽

Cited By ~ 39

Author(s):

D. G. Diel ◽

G. Delhon ◽

S. Luo ◽

E. F. Flores ◽

D. L. Rock

Keyword(s):

Immune Responses ◽

Signaling Pathway ◽

Viral Infections ◽

Nuclear Translocation ◽

Orf Virus ◽

Necrosis Factor Alpha ◽

Iκb Kinase ◽

Genes Expression ◽

Tnf Α ◽

Factor Alpha

ABSTRACT The parapoxvirus orf virus (ORFV) is a pathogen of sheep and goats that has been used as a preventive and therapeutic immunomodulatory agent in several animal species. However, the functions (genes, proteins, and mechanisms of action) evolved by ORFV to modulate and manipulate immune responses are poorly understood. Here, the novel ORFV protein ORFV024 was shown to inhibit activation of the NF-κB signaling pathway, an important modulator of early immune responses against viral infections. Infection of primary ovine cells with an ORFV024 deletion mutant virus resulted in a marked increase in expression of NF-κB-regulated chemokines and other proinflammatory host genes. Expression of ORFV024 in cell cultures significantly decreased lipopolysaccharide (LPS)- and tumor necrosis factor alpha (TNF-α)-induced NF-κB-responsive reporter gene expression. Further, ORFV024 expression decreased TNF-α-induced phosphorylation and nuclear translocation of NF-κB-p65, phosphorylation, and degradation of IκBα, and phosphorylation of IκB kinase (IKK) subunits IKKα and IKKβ, indicating that ORFV024 functions by inhibiting activation of IKKs, the bottleneck for most NF-κB activating stimuli. Although ORFV024 interferes with activation of the NF-κB signaling pathway, its deletion from the OV-IA82 genome had no significant effect on disease severity, progression, and time to resolution in sheep, indicating that ORFV024 is not essential for virus virulence in the natural host. This represents the first description of a NF-κB inhibitor encoded by a parapoxvirus.

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Hepatoprotective Effect of Polysaccharides Isolated from Dendrobium officinale against Acetaminophen-Induced Liver Injury in Mice via Regulation of the Nrf2-Keap1 Signaling Pathway

Oxidative Medicine and Cellular Longevity ◽

10.1155/2018/6962439 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 12

Author(s):

Guosheng Lin ◽

Dandan Luo ◽

Jingjing Liu ◽

Xiaoli Wu ◽

Jinfen Chen ◽

...

Keyword(s):

Liver Injury ◽

Signaling Pathway ◽

Nuclear Translocation ◽

Hepatoprotective Effect ◽

Dendrobium Officinale ◽

Regulatory Subunit ◽

Heme Oxygenase 1 ◽

Related Factor ◽

Glutamate Cysteine Ligase ◽

Nrf2 Signaling Pathway

The effect of polysaccharides isolated from Dendrobium officinale (DOP) on acetaminophen- (APAP-) induced hepatotoxicity and the underlying mechanisms involved are investigated. Male Institute of Cancer Research (ICR) mice were randomly assigned to six groups: (1) control, (2) vehicle (APAP, 230 mg/kg), (3) N-acetylcysteine (100 mg/kg), (4) 50 mg/kg DOP, (5) 100 mg/kg DOP, and (6) 200 mg/kg DOP. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in the serum and glutathione (GSH), malondialdehyde (MDA), catalase (CAT), total antioxidant capacity (T-AOC), myeloperoxidase (MPO), and reactive oxygen species (ROS) levels in the liver were determined after the death of the mice. The histological examination of the liver was also performed. The effect of DOP on the Kelch-like ECH-associated protein 1- (Keap1-) nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway was evaluated using Western blot analysis and real-time polymerase chain reaction (PCR). The results showed that DOP treatment significantly alleviated the hepatic injury. The decrease in ALT and AST levels in the serum and ROS, MDA, and MPO contents in the liver, as well as the increases in GSH, CAT, and T-AOC in the liver, were observed after DOP treatment. DOP treatment significantly induced the dissociation of Nrf2 from the Nrf2−Keap1 complex and promoted the Nrf2 nuclear translocation. Subsequently, DOP-mediated Nrf2 activation triggered the transcription and expressions of the glutamate–cysteine ligase catalytic (GCLC) subunit, glutamate–cysteine ligase regulatory subunit (GCLM), heme oxygenase-1 (HO-1), and NAD(P)H dehydrogenase quinone 1 (NQO1) in APAP-treated mice. The present study revealed that DOP treatment exerted potentially hepatoprotective effects against APAP-induced liver injury. Further investigation about mechanisms indicated that DOP exerted the hepatoprotective effect by suppressing the oxidative stress and activating the Nrf2−Keap1 signaling pathway.

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Rice protein hydrolysates (RPHs) inhibit the LPS-stimulated inflammatory response and phagocytosis in RAW264.7 macrophages by regulating the NF-κB signaling pathway

RSC Advances ◽

10.1039/c6ra08927e ◽

2016 ◽

Vol 6 (75) ◽

pp. 71295-71304 ◽

Cited By ~ 10

Author(s):

Li Wen ◽

Yuehua Chen ◽

Li Zhang ◽

Huixin Yu ◽

Zhou Xu ◽

...

Keyword(s):

Inflammatory Response ◽

Signaling Pathway ◽

Nuclear Translocation ◽

Protein Hydrolysates ◽

Rice Protein ◽

Phagocytic Ability ◽

Raw264.7 Macrophages ◽

Tnf Α

Different RPH components inhibit LPS-induced NO and TNF-α production. RPHs-C-7-3 inhibits the expression of pro-inflammatory expression. RPHs-C-7-3 suppresses the LPS-stimulated phagocytic ability. RPHs-C-7-3 regulates the nuclear translocation of p65.

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Berry Phenolic and Volatile Extracts Inhibit Pro-Inflammatory Cytokine Secretion in LPS-Stimulated RAW264.7 Cells through Suppression of NF-κB Signaling Pathway

Antioxidants ◽

10.3390/antiox9090871 ◽

2020 ◽

Vol 9 (9) ◽

pp. 871

Author(s):

Inah Gu ◽

Cindi Brownmiller ◽

Nathan B. Stebbins ◽

Andy Mauromoustakos ◽

Luke Howard ◽

...

Keyword(s):

Signaling Pathway ◽

Nuclear Translocation ◽

Complex Mixture ◽

Limited Information ◽

Potential Health ◽

Tnf Α ◽

Anti Inflammatory ◽

Factor Α ◽

Raw264.7 Macrophage ◽

Necrosis Factor

Berries are a rich source of phytochemicals, especially phenolics well known for protective activity against many chronic diseases. Berries also contain a complex mixture of volatile compounds that are responsible for the unique aromas of berries. However, there is very limited information on the composition and potential health benefits of berry volatiles. In this study, we isolated phenolic and volatile fractions from six common berries and characterized them by HPLC/HPLC-MS and GC/GC-MS, respectively. Berry phenolic and volatile fractions were evaluated for an anti-inflammatory effect using lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells by measuring levels of pro-inflammatory cytokines and the nuclear factor-kappa B (NF-κB) signaling pathway. Results showed that LPS-induced excessive production of nitric oxide (NO), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), which were inhibited by berry phenolic and volatile extracts. Moreover, berry phenolic and volatile extracts reduced the nuclear translocation of NF-κB by blocking the phosphorylation of p65 and degradation of IκBα. These findings showed that berry volatiles from six berries had comparable anti-inflammatory effects to berry phenolics through the suppression of pro-inflammatory mediators and cytokines expression via NF-κB down-regulation, despite being present in the fruit at a lower concentration.

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Protective Effects of MicroRNA-126 on Human Cardiac Microvascular Endothelial Cells Against Hypoxia/Reoxygenation-Induced Injury and Inflammatory Response by Activating PI3K/Akt/eNOS Signaling Pathway

Cellular Physiology and Biochemistry ◽

10.1159/000477597 ◽

2017 ◽

Vol 42 (2) ◽

pp. 506-518 ◽

Cited By ~ 52

Author(s):

Hong-Hui Yang ◽

Yan Chen ◽

Chuan-Yu Gao ◽

Zhen-Tian Cui ◽

Jian-Min Yao

Keyword(s):

Cell Proliferation ◽

Inflammatory Response ◽

Signaling Pathway ◽

Cell Apoptosis ◽

Control Group ◽

Protective Effects ◽

Enos Expression ◽

Lumen Formation ◽

Tnf Α ◽

Cardiac Microvascular Endothelial Cells

Objective: This study explored the protective effects of the microRNA-126 (miR-126)-mediated PI3K/Akt/eNOS signaling pathway on human cardiac microvascular endothelial cells (HCMECs) against hypoxia/reoxygenation (H/R)-induced injury and the inflammatory response. Methods: Untreated HCMECs were selected for the control group. After H/R treatment and cell transfection, the HCMECs were assigned to the H/R, miR-126 mimic, mimic-negative control (NC), miR-126 inhibitor, inhibitor-NC, wortmannin (an inhibitor of PI3K) and miR-126 mimic + wortmannin groups. Super oxide dismutase (SOD), nitric oxide (NO), vascular endothelial growth factor (VEGF) and reactive oxygen species (ROS) were measured utilizing commercial kits. Quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were performed to detect miR-126 expression and the mRNA and protein expression of inflammatory factors. Western blotting was used to determine the expression of key members in the PI3K/Akt/eNOS signaling pathway. ACCK-8 assay and flow cytometry were employed to examine cell proliferation and apoptosis, respectively. The angiogenic ability in each group was detected by the lumen formation test. Results: Compared to the control group, p/t-PI3K, p/t-Akt and p/t-eNOS expression, NO, VEGF and SOD levels, cell proliferation and in vitro lumen formation ability were decreased, while the ROS content, interleukin (IL)-6, IL-10 and tumor necrosis factor (TNF)-α expression and cell apoptosis were significantly increased in the H/R, mimic-NC, miR-126 inhibitor, inhibitor-NC, wortmannin and miR-126 mimic + wortmannin groups. Additionally, in comparison with the H/R group, the miR-126 mimic group had elevated p/t-PI3K, p/t-Akt and p/t-eNOS expression, increased NO, VEGF and SOD contents, and strengthened cell proliferation and lumen formation abilities but also exhibited decreased ROS content, reduced IL-6, IL-10 and TNF-α expressions, and weakened cell apoptosis, while the miR-126 inhibitor and wortmannin group exhibited the opposite results. Furthermore, decreased p/t-PI3K, p/t-Akt and p/t-eNOS expressions, decreased NO, VEGF and SOD contents, cell proliferation and lumen formation abilities, as well as increased ROS content, increased IL-6, IL-10 and TNF-α expression, and increased cell apoptosis were observed in the miR-126 mimic + wortmannin group compared to themiR-126 mimic group. Conclusions: These findings indicated that miR-126 protects HCMECs from H/R-induced injury and inflammatory response by activating the PI3K/Akt/ eNOS signaling pathway.

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Santonin-Related Compound 2 Inhibits the Nuclear Translocation of NF-κB Subunit p65 by Targeting Cysteine 38 in TNF-α-Induced NF-κB Signaling Pathway

Bioscience Biotechnology and Biochemistry ◽

10.1271/bbb.120619 ◽

2012 ◽

Vol 76 (12) ◽

pp. 2360-2363 ◽

Cited By ~ 11

Author(s):

Ryuichi TAMURA ◽

Kyoko MORIMOTO ◽

Seiya HIRANO ◽

Liyan WANG ◽

Ming ZHAO ◽

...

Keyword(s):

Signaling Pathway ◽

Related Compound ◽

Nuclear Translocation ◽

Tnf Α

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DAP Inhibits the TNF-α-Induced Inflammatory Response by Modulating the MAPK Signaling Pathway in Synovial Cells

10.21203/rs.3.rs-394300/v1 ◽

2021 ◽

Author(s):

Jieying Wang ◽

Nanzhen Kuang ◽

Mao zheng ◽

Chan Dai ◽

Huimin Deng ◽

...

Keyword(s):

Inflammatory Response ◽

Signaling Pathway ◽

Nuclear Translocation ◽

Mapk Signaling ◽

Mapk Signaling Pathway ◽

Inflammatory Factors ◽

Control Group ◽

Synovial Cells ◽

Tnf Α ◽

Model Control

Abstract Daphnetin(DAP) is extracted from Daphne odora var. marginata and contains coumarin compounds, which have a good anti-inflammatory analgesic effect. In this study, we investigated whether daphnetin can reduce the TNF-α-induced inflammatory response by inhibiting the MAPK signaling pathway in the synovial cells of CIA rats. A model of synovial cells was constructed using CIA rats induced by TNF-α. The expression of inflammatory cytokines in the synovial cells of CIA rats was observed by real-time PCR and ELISA. The expression and nuclear translocation of MAPK signaling pathway proteins were detected by Western blot and immunofluorescence assays. The results show that the mRNA and protein levels of IL-6, TGF-β, MMP-3 and MMP-13 were significantly lower than those in the culture supernatant of the model control group. The synovial cells of CIA rats induced by TNF-α exhibited decreased expression of p-p38, p-ERK1/2 and p-JNK in the nucleus. In conclusion, daphnetin can affect the activation of the MAPK signaling pathway and reduce the expression of inflammatory factors by inhibiting the MAPK signaling pathway, which plays a role in anti-rheumatic inflammation.

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Positive Regulation of IκB Kinase Signaling by Protein Serine/Threonine Phosphatase 2A

Journal of Biological Chemistry ◽

10.1074/jbc.m506093200 ◽

2005 ◽

Vol 280 (43) ◽

pp. 35974-35982 ◽

Cited By ~ 58

Author(s):

Arlene E. Kray ◽

Robert S. Carter ◽

Kevin N. Pennington ◽

Rey J. Gomez ◽

Laura E. Sanders ◽

...

Keyword(s):

Mammalian Cells ◽

Cellular Response ◽

Kinase Activity ◽

Nuclear Translocation ◽

Regulatory Role ◽

Regulatory Subunit ◽

Iκb Kinase ◽

Phosphatase 2A ◽

In Cells

Transcription factor NF-κB plays a key regulatory role in the cellular response to pro-inflammatory cytokines such as tumor necrosis factor-α (TNF). In the absence of TNF, NF-κB is sequestered in the cytoplasm by inhibitory IκB proteins. Phosphorylation of IκBby the β-catalytic subunit of IKK, a multicomponent IκB kinase, targets the inhibitor for proteolytic destruction and facilitates nuclear translocation of NF-κB. This pathway is initiated by TNF-dependent phosphorylation of T loop serines in IKKβ, which greatly stimulates IκB kinase activity. Prior in vitro mixing experiments indicate that protein serine/threonine phosphatase 2A (PP2A) can dephosphorylate these T loop serines and inactivate IKK, suggesting a negative regulatory role for PP2A in IKK signaling. Here we provided several in vivo lines of evidence indicating that PP2A plays a positive rather than a negative role in the regulation of IKK. First, TNF-induced degradation of IκB is attenuated in cells treated with okadaic acid or fostriecin, two potent inhibitors of PP2A. Second, PP2A forms stable complexes with IKK in untransfected mammalian cells. This interaction is critically dependent on amino acid residues 121–179 of the IKKγ regulatory subunit. Third, deletion of the PP2A-binding site in IKKγ attenuates T loop phosphorylation and catalytic activation of IKKβ in cells treated with TNF. Taken together, these data provide strong evidence that the formation of IKK·PP2A complexes is required for the proper induction of IκB kinase activity in vivo.

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