Osthole alleviates inflammation by down-regulating NF-κB signaling pathway in traumatic brain injury

Traumatic brain injury (TBI) is a common neurotrosis disorder of the central nervous system (CNS), which has dramatic consequences on the integrity of damaged tissue. In this study, we investigated the neuroprotective effect and anti-inflammatory actions of osthole, a natural coumarin derivative, in both in vivo and in vitro TBI models. We first prepared a mouse model of cortical stab wound brain injury, investigated the capacity for osthole to prevent secondary brain injury and further examined the underlying mechanism. We revealed that osthole significantly improved the neurological function, increased the number of neurons beside injured site. Additionally, osthole treatment reduced the expression of microglia and glial scar, lowered the level of the proinflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α), and blocked the activation of nuclear factor kappa B (NF-κB). Furthermore, the protective effect of osthole was also examined in SH-SY5Y cells subjected to scratch injury. Treatment of osthole prominently suppressed cell apoptosis and inflammatory factors release by blocking injury-induced IκB-α phosphorylation and NF-κB translocation, and upregulated the IκB-α which functions in the NF-κB signaling pathway of SH-SY5Y cells. However, NF-κB signaling pathway was inhibited by pyrrolidine dithiocarbamate (PDTC), an NF-κB inhibitor, the anti-inflammatory effect of osthole was abolished. In conclusion, our findings demonstrated that osthole attenuated inflammatory response by inhibiting the NF-κB pathway in TBI.     

Ginsenosides compound K and Rh2 inhibit tumor necrosis factor-α-induced activation of the NF-κB and JNK pathways in human astroglial cells

Ginsenosides, the main component of Panax ginseng, have been known for the anti-inflammatory and anti-proliferative activities. In this study, we investigated the molecular mechanisms responsible for the anti-inflammatory effects of ginsenosides on activated astroglial cells. Among 13 different ginsenosides, intestinal bacterial metabolites Rh₂ and compound K (C-K) showed a significant inhibitory effect on tumor necrosis factor-α (TNF-α)-induced expression of intercellular adhesion molecule-1 in human astroglial cells. Pretreatment with C-K or Rh₂ suppressed TNF-α-induced phosphorylation of IκBα kinase and the subsequent phosphorylation and degradation of IκBα. Additionally, the same treatment inhibited TNF-α-induced phosphorylation of MKK4 and the subsequent activation of the JNK-AP-1 pathway. The inhibitory effect of ginsenosides on TNF-α-induced activation of the NF-κB and JNK pathways was not observed in human monocytic U937 cells. These results collectively indicate that ginsenoside metabolites C-K and Rh₂ exert anti-inflammatory effects by the inhibition of both NF-κB and JNK pathways in a cell-specific manner.     

Activation of adenosine A3 receptor suppresses lipopolysaccharide-induced TNF-α production through inhibition of PI 3-kinase/Akt and NF-κB activation in murine BV2 microglial cells

Adenosine is an endogenous nucleoside that regulates many processes, including inflammatory responses, through activation of its receptors. Adenosine receptors have been reported to be expressed in microglia, which are major immune cells of brain, yet little is known about the role of adenosine receptors in microglial cytokine production. Thus, we investigated the effect of adenosine and adenosine A₃ receptor ligands on LPS-induced tumor necrosis factor (TNF-α) production and its molecular mechanism in mouse BV2 microglial cells. Adenosine and Cl-IB-MECA, a specific adenosine A₃ receptor agonist, suppressed LPS-induced TNF-α protein and mRNA levels. Moreover, MRS1523, a selective A₃ receptor antagonist, blocked suppressive effects of both adenosine and Cl-IB-MECA on TNF-α. We further examined the effect of adenosine on signaling molecules, such as PI 3-kinase, Akt, p38, ERK1/2, and NF-κB, which are involved in the regulation of inflammatory responses. Adenosine inhibited LPS-induced phosphatidylinositol (PI) 3-kinase activation and Akt phosphorylation, whereas it had no effect on the phosphorylation of p38 and ERK1/2. We also found that adenosine as well as Cl-IB-MECA inhibited LPS-induced NF-κB DNA binding and luciferase reporter activity. Taken together, these results suggest that adenosine A₃ receptor activation suppresses TNF-α production by inhibiting PI 3-kinase/Akt and NF-κB activation in LPS-treated BV2 microglial cells.     

Thymol Inhibits LPS-Stimulated Inflammatory Response via Down-Regulation of NF-κB and MAPK Signaling Pathways in Mouse Mammary Epithelial Cells

Thymol is a natural monoterpene phenol primarily found in thyme, oregano, and tangerine peel. It has been shown to possess anti-inflammatory property both in vivo and in vitro. In the present paper, we studied the anti-inflammatory effect of thymol in lipopolysaccharide (LPS)-stimulated mouse mammary epithelial cells (mMECs). The mMECs were stimulated with LPS in the presence or absence of thymol (10, 20, 40 μg/mL). The concentrations of tumor necrosis factor α (TNF-α), interleukin (IL)-6, and IL-1β in the supernatants of culture were determined using enzyme-linked immunosorbent assay. Cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), nuclear factor-κB (NF-κB), and inhibitor protein of NF-κB (IκBα) were measured using western blot. The results showed that thymol markedly inhibited the production of TNF-α and IL-6 in LPS-stimulated mMECs. The expression of iNOS and COX-2 was also suppressed by thymol in a dose-dependent manner. Furthermore, thymol blocked the phosphorylation of IκBα, NF-κB p65, ERK, JNK, and p38 mitogen-activated protein kinases (MAPKs) in LPS-stimulated mMECs. These results indicate that thymol exerted anti-inflammatory property in LPS-stimulated mMECs by interfering the activation of NF-κB and MAPK signaling pathways. Thereby, thymol may be a potential therapeutic agent against mastitis.     

Molecular Basis of the Anti-Inflammatory Property Exhibited by Cyclo-Pentano Phenanthrenol Isolated from Lippia nodiflora

The objective of this study was to assess the anti-inflammatory potential of the active molecule isolated from Lippia nodiflora and to understand its molecular dynamics in Vitro inflammation models. Human Peripheral Blood Mononuclear Cells were used as models to study mitogen induced lymphocyte proliferation, cytokine mRNA expression (TNF-α, IL-1β and IL-6) and intracellular protein levels of pro-inflammatory mediators (MAPK and NF-κB). The NO release levels, on treatment with the extract and molecule, were correlated with the underlying iNOS mRNA expression in the murine macrophage cell line RAW 264.7. RT-PCR for COX-2, MMP2 and MMP9 were also performed in the cell line. The rat basophilic leukemia cell line RBL-2H3 was used as an in Vitro model for PLA2 activity. Then, 20 μg/ml of Lippia nodiflora crude methanol extract and 10 μg/ml of the purified CPP were used for subsequent studies based on the IC50 values obtained in the proliferation assay. Results demonstrate that the isolated Cyclo-pentano phenanthrenol inhibits TNF-α, IL-1β and IL-6 expression, NO release via iNOS suppression, prostaglandin biosynthesis via PLA2 and COX-2 inhibition and the activation of intracellular targets, MAPK and NF-κB. We conclude, cyclo-pentano phenanthrenol exerts its anti-inflammatory effect via inhibition of MAPK phosphorylation and NF-κB translocation.     

Isorhamnetin attenuates TNF-α-induced inflammation,proliferation, and migration in human bronchial epithelial cells via MAPK and NF-κB pathways

Isorhamnetin has distinct anti-inflammatory activity and inhibits cell proliferation and migration. These effects are also involved in the pathogenesis of asthma. However, the effect of isorhamnetin on bronchial epithelial cells in patients with asthma has not been examined. Cells of human bronchial epithelial cell line BEAS-2B were cultured with isorhamnetin and tumor necrosis factor (TNF)-α. The effects of isorhamnetin on BEAS-2B cell viability were assessed using CCK8 assay. The EdU (5-ethynyl-2′-deoxyuridine) cell proliferation assay was performed to assess cell proliferation. BEAS-2B cell migration was measured using Transwell and wound healing assays. Real-time PCR and enzyme-linked immunosorbent assay were conducted to measure the expression of pro-inflammatory cytokines. Protein expression levels were determined by western blotting. Immunofluorescence was used to detect nuclear translocation of nuclear factor kappa B (NF-κB). We found that isorhamnetin at 20 and 40 μM reduced the proliferation of BEAS-2B cells induced by TNF-α. Isorhamnetin significantly decreased the expression of interleukin (IL)-1β, IL-6, IL-8, and C-X-C motif chemokine ligand 10 in BEAS-2B cells induced by TNF-α. Additionally, 10 μM isorhamnetin effectively reduced cell migration induced by TNF-α. Treatment with isorhamnetin inhibited the phosphorylation of mitogen-activated protein kinase (MAPK) and NF-κB pathways induced by TNF-α. In summary, isorhamnetin inhibited the inflammation, proliferation, and migration of BEAS-2B cells by regulating the MAPK and NF-κB signaling pathways and is a drug candidate for asthma.     

Artemisinin inhibits inflammatory response via regulating NF-κB and MAPK signaling pathways

Artemisinin, isolated from the Chinese plant Artemisia annua, has been used for many years to treat different forms of malarial parasites. In this study, we explored the anti-inflammatory activity of artemisinin and the underlying mechanism of this action. We demonstrated that the anti-inflammatory effects of artemisinin in TPA-induced skin inflammation in mice. Then the artemisinin significantly inhibited the expression of NF-κB reporter gene induced by TNF-α in a dose-dependent manner. Artemisinin also inhibited TNF-α induced phosphorylation and degradation of IκBα, p65 nuclear translocation. Artemisinin also has an impact on upstream signaling of IKK through the inhibition of expression of adaptor proteins, TNF receptor-associated factor 2 (TRAF2) and receptor interacting protein 1 (RIP1). Furthermore, pretreatment of cells with artemisinin prevented the TNF-α-induced expression of NF-κB target genes, such as anti-apoptosis (c-IAP1, Bcl-2, and FLIP), proliferation (COX-2, cyclinD1), invasion (MMP-9), angiogenesis (VEGF), and major inflammatory cytokines (TNF-α, iNOS, and MCP1). We also proved that artemisinin potentiated TNF-α-induced apoptosis. Moreover, artemisinin significantly impaired the ROS production and phosphorylation of p38 and ERK, but did not affect the phosphorylation of JNK. Taken together, artemisinin may be a potentially useful therapeutic agent for inflammatory-related diseases.     

辛伐他汀对同型半胱氨酸诱导的HUVEC的毒性和炎症反应的影响及分子机制

目的：探讨辛伐他汀对同型半胱氨酸(HCY)诱导的内皮细胞毒性和炎症的抑制作用及其分子机制。 方法: 采用MTT检测细胞活性，通过DCFH-DA检测活性氧的生成，Western blotting分析相关蛋白的表达，凝胶滞留法(EMSA)分析NF-κB的DNA结合活性。 结果： HCY处理后，MTT检测发现内皮细胞存活率显著低于对照，流式细胞仪的结果表明活性氧的水平也显著升高。经不同浓度的辛伐他汀预处理后，可以显著地抑制HCY诱导的内皮细胞存活率的下降以及活性氧水平的升高。Western blotting与ELISA结果发现辛伐他汀抑制TNF-α、IL-6、MCP-1及ICAM-1的表达水平。EMSA和Western blotting检测结果表明辛伐他汀抑制HCY介导的p38磷酸化水平以及通过抑制IκBα磷酸化而抑制IκBα蛋白的降解，阻断HCY诱导NF-κB的激活。 结论： 辛伐他汀对HCY介导的内皮细胞毒性及炎症反应有明显的抑制作用，可能是通过阻断ROS-p38-NF-κB通路实现的。     

Honokiol suppresses TNF-α-induced migration and matrix metalloproteinase expression by blocking NF-κB activation via the ERK signaling pathway in rat aortic smooth muscle cells

Honokiol, a small-molecule polyphenol derived and isolated from the Chinese medicinal herb Magnolia officinalis, has been shown to possess a wide range of pharmacological activities. In the present study, we aimed to investigate the effects of honokiol on tumor necrosis factor-α (TNF-α)-induced migration in rat aortic smooth muscle cells (RASMCs). We found that honokiol inhibited TNF-α-induced RASMC proliferation and migration in a dose-dependent manner. At the molecular level, pretreatment with honokiol blocked TNF-α-induced protein expression of matrix metalloproteinase (MMP)-2 and MMP-9, nuclear factor (NF)-κB activation, and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation. Moreover, NF-κB inhibitor (BAY 11-7028) and ERK inhibitor (U0126) also mimicked the inhibitory effects of honokiol in TNF-α-treated RASMCs. In conclusion, these results indicate that honokiol suppresses TNF-α-induced migration and MMP expression by blocking NF-κB activation via the ERK signaling pathway in RASMCs. Our findings support honokiol as a promising novel agent for the prevention and treatment of atherosclerosis.     

Regulatory effect of IL-38 on NF-κB pathway in systemic lupus erythematosus

BackgroundIL-38 is a newly identified cytokine that exhibits immunosuppression effects. However, there are few studies focusing on the effects and mechanisms of IL-38 in the systemic lupus erythematosus (SLE).AimWe investigated the effects and mechanisms of IL-38 on NF-κB signaling pathway in SLE.MethodsLevels of IL-38, IL-36R, IL-1RAcP, IKKα/β, NF-κB, TNF-α and anti-dsDNA antibody levels in peripheral blood of SLE patients, and in peripheral blood and kidney tissues of MRL/lpr mice, were examined with real-time PCR, ELISA, Western blot and immunohistochemistry. Pathological changes of kidney were detected with PAS staining. Recombinant human IL-38 protein and IL-38 siRNA were used to intervene the PBMCs of SLE patients and MRL/lpr mice.ResultsThe mRNA and protein levels of IL-38 in peripheral blood of SLE patients decreased and were positively correlated. The mRNA and protein levels of IKKα/β, NF-κB, and TNF-α increased, especially in patients with active SLE. There was a negative correlation between IL-38 and the levels of IKKα/β, NF-κB and TNF-α in SLE patients. In vitro experiments showed that the levels of IKKα/β, NF-κB and TNF-α, and anti-dsDNA antibodies decreased in PBMCs of SLE patients after treatment with human recombinant IL-38 protein. These effects were reversed after IL-38 siRNA intervention. Consistent results were obtained on IL-38, IKKα/β, NF-κB, and TNF-α in MRL/lpr lupus mice after treatment with IL-38 protein or IL-38 shRNA. Additionally, kidney function (reflected by creatinine and blood urea nitrogen), anti-dsDNA antibody, complement C3, and urinary protein levels decreased after treatment with IL-38 protein but increased after IL-38 shRNA treatment. PAS staining showed IL-38 protein treatment induced mild hyperplasia of glomerular mesangial cells and a small amount of lymphocyte infiltration. However, these were aggravated after IL-38 shRNA treatment.ConclusionIL-38 may be involved in the occurrence and development of SLE by regulating the NF-κB signaling pathway. This study only discussed the relationship between IL-38 and NF-κB, and more biological functions of IL-38 need to be further studied.     

Immune stimulatory effects of Loranthi ramulus on macrophages through the increase of NO and TNF-α

The activation of macrophages by microorganisms plays an important role in host defense and immunopathology. Loranthi ramulus (LR) is commonly used as a traditional drug and health food in Korea. Here, we investigated the regulatory effects of LR on macrophage-mediated immune responses. Treatment of macrophages with LR resulted in the enhanced cell-surface expression of CD80, CD86 and major histocompatibility complex (MHC) class II, as well as the enhanced production of nitric oxide (NO) and tumor necrosis factor (TNF)-α, and also iNOS and TNF-α mRNA expression. These alterations of LR-treated cells were associated with the activation of NF-κB and mitogen-activated protein kinases (MAPKs). LR increased the phosphorylation of MAPKs (JNK, ERK1/2, p38 MAPK) and the activation of NF-κB in Raw 264.7 cells. These results suggest that LR has increased NO and TNF-α production through phosphorylation of all three MAPKs following IκBα degradation and NF-κB activation. In conclusion, our results demonstrate that LR can effectively promote the activation of macrophages, suggesting that LR may possess the potential to regulate immune responses.     

EstA protein,a novel virulence factor of Streptococcus pneumoniae, induces nitric oxide and pro-inflammatory cytokine production in RAW 264.7 macrophages through NF-κB/MAPK

In the present study we characterized the molecular mechanism by which esterase A (EstA) protein, a novel virulence factor of Streptococcus pneumoniae induces inflammation. Stimulation of RAW 264.7 macrophages with purified EstA protein induced the expression of inducible nitrogen oxide synthase (iNOS) mRNA and nitrogen oxide (NO) production in a concentration-dependent manner. Inhibitors of iNOS, NF-κB, p38 and ERK 1/2 MAPK pathways significantly decreased (50–78%) EstA-induced NO production. Similarly, EstA induced TNF-α, IL-1β and IL-6 mRNA expression in RAW 264.7 macrophages in a dose-dependent manner, and pre-treatment of the cell cultures with specific NF-κB, p38 and ERK 1/2 MAPK pathway inhibitors significantly decreased EstA-induced TNF-α, IL-1β and IL-6 protein production. Furthermore, immunoblot analysis revealed the degradation of the inhibitory kappa B (IKB-α) in response to EstA stimulation. Taken together, our data suggests that EstA protein is a novel inducer of NO and pro-inflammatory cytokines by activating the NF-κB, p38 and ERK 1/2 MAPK pathways during inflammatory responses. Future studies on the upstream protein kinases of the MAPK/NF-κB pathways and the kinetics of cytokine production will provide further details into the mechanism of EstA-induced inflammatory response.     

Andrographolide attenuates microglia-mediated Aβ neurotoxicity partially through inhibiting NF-κB and JNK MAPK signaling pathway

Neuroinflammation plays a critical role in the pathogenesis of several neurodegenerative diseases, including Alzheimer’s disease (AD). Microglial cells after activated play critical roles in development of neuroinflammation, and may accelerate the progression of AD. Andrographolide (ANDRO), a potent naturally extracted substance, has been demonstrated to exert suppressive effects on LPS-induced inflammation by modulating macrophage and microglia overactivation. Whereas in AD, β-amyloid (Aβ) peptides have been considered as a potent activator of neuroinflammation, the effect of ANDRO on Aβ-induced neuroinflammation has not been examined. In this study, we investigated the effects of ANDRO on Aβ(1–42)-induced neuroinflammation. We found that ANDRO significantly protected neuronal cells against microglia-mediated Aβ(1–42) toxicity and attenuated the release of preinflammatory productions such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), nitric oxide (NO), and prostaglandin E₂ (PGE₂). It also downregulated the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in microglial cells. Further the involved mechanism study demonstrated that ANDRO inhibited the nuclear translocation of nuclear factor-κB (NF-κB) by affecting IκB phosphorylation, and attenuated Aβ(1–42)-induced JNK–MAPK overactivation. In summary, this study, for the first time, revealed ANDRO reduced inflammation-mediated neuronal damage by blocking inflammatory responses of microglial cells to Aβ(1–42), suggesting ANDRO may be an effective agent in modulating neuroinflammatory process in AD.     

p38 Mitogen-Activated Protein Kinase in beryllium-induced dendritic cell activation

Dendritic cells (DC) play a role in the regulation of immune responses to haptens, which in turn impact DC maturation. Whether beryllium (Be) is able to induce DC maturation and if this occurs via the MAPK pathway is not known. Primary monocyte-derived DCs (moDCs) models were generated from Be non-exposed healthy volunteers as a non-sensitized cell model, while PBMCs from BeS (Be sensitized) and CBD (chronic beryllium disease) were used as disease models. The response of these cells to Be was evaluated. The expression of CD40 was increased significantly (p < 0.05) on HLA-DP Glu69+ moDCs after 100 μM BeSO₄-stimulation. BeSO₄ induced p38MAPK phosphorylation, while IκB-α was degraded in Be-stimulated moDCs. The p38 MAPK inhibitor SB203580 blocked Be-induced NF-κB activation in moDCs, suggesting that p38MAPK and NF-κB are dependently activated by BeSO₄. Furthermore, in BeS and CBD subjects, SB203580 downregulated Be-stimulated proliferation in a dose-dependent manner, and decreased Be-stimulated TNF-α and IFNγ cytokine production. Taken together, this study suggests that Be-induces non-sensitized Glu69+ DCs maturation, and that p38MAPK signaling is important in the Be-stimulated DCs activation as well as subsequent T cell proliferation and cytokine production in BeS and CBD. In total, the MAPK pathway may serve as a potential therapeutic target for human granulomatous lung diseases.     

Calcitonin protects chondrocytes from lipopolysaccharide-induced apoptosis and inflammatory response through MAPK/Wnt/NF-κB pathways

Calcitonin (CT) is an anti-absorbent, which has long been used for treatment of osteoporosis. However, little information is available about the effects of CT on osteoarthritis (OA). This study was mainly aimed to explore the effects of CT on the treatment of OA, as well as the underlying mechanisms. Chondrocytes were isolated from immature mice and then were incubated with lipopolysaccharide (LPS), CT, small interfering (si) RNA against bone morphogenetic protein (BMP)-2, and/or the inhibitors of MAPK/Wnt/NF-κB pathway. Thereafter, cell viability, apoptosis, nitric oxide (NO) and inflammatory factors productions, and expression levels of cartilage synthesis protein key factors, cartilage-derived morphogenetic protein (CDMP) 1, SRY (sex-determining region Y)-box 9 protein (SOX9), and MAPK/Wnt/NF-κB pathways key factors were determined. CT significantly reversed LPS-induced cell viability decrease, apoptosis increase, the inflammatory factors and NO secretion, the abnormally expression of cartilage synthesis proteins and the activation of MAPK/Wnt/NF-κB pathways (P < 0.05). In addition, we observed that administration of the inhibitors of MAPK/Wnt/NF-κB pathways statistically further increased the levels of CDMP1 and SOX9 (P < 0.05). Suppression of BMP-2 decreased the levels of CDMP1 and SOX9 and activated MAPK/Wnt/NF-κB pathways, and could partially abolish CT-modulated the expression changes in CDMP1 and SOX9, and MAPK/Wnt/NF-κB pathways key factors (P < 0.05). The results showed that CT protects chondrocytes from LPS-induced apoptosis and inflammatory response by regulating BMP-2 and thus blocking MAPK/Wnt/NF-κB pathways.     

Anti-Inflammatory Mechanism of a Folk Herbal Medicine,Duchesnea indica (Andr) Focke at RAW264.7 Cell Line

This study is to explore the anti-inflammatory mechanism of the ethanol extract of Duchesnea indica (Andr) Focke. An inflammatory cellular model was established by addition of lipopolysaccharide (LPS) on RAW264.7 cell line. The cellular secretion of TNF-α, IL-1β, IL-6, NO and IL-10 in supernatant, mRNA expression of TNF-α, COX-2, iNOS and HO-1, protein expression of COX-2 and HO-1, and activation of NF-κB were assayed by ELISA, the Griess method, real-time quantitative PCR, and Western blot and immunocytochemistry method, respectively. The ethanol extract of D. indica not only reduced production of pro-inflammatory cytokines and mediators and blocked NF-κB activation, but also slightly promoted release of the anti-inflammatory mediator HO-1 and suppressed IL-10 secretion. In conclusion, the anti-inflammatory effects of the extract of D. indica are attributed to the suppression of pro-inflammatory cytokines and mediators by blocking NF-κB activation. The extract of D. indica can also slightly promote HO-1 production to reduce inflammation.     

Acacetin inhibits expression of E-selectin on endothelial cells through regulation of the MAP kinase signaling pathway and activation of NF-κB

Abstract

Since E-selectin-mediated adhesion of leukocytes or tumor cells to the vascular endothelium is a key early event in the initiation of inflammatory response and cancer metastasis, E-selectin inhibition is thought to be a good target for therapeutic intervention. Several flavones have been shown to have anti-inflammatory and anticancer properties. In the present study, we investigated the effects of plant flavones on expression of E-selectin in human umbilical vein endothelial cells. Among 11 flavones, acacetin strongly inhibited TNF-α-induced E-selectin expression in HUVECs. Acacetin suppressed the TNF-α-induced phosphorylation of p38 but did not inhibit TNF-α-induced phosphorylations of JNK and ERK. Acacetin also inhibited the activation of NF-κB by stimulation with TNF-α. Furthermore, adhesion of monocytes to TNF-α-treated endothelial cells was inhibited by cotreatment with acacetin. These results suggest that acacetin inhibits the expression of E-selectin by regulation of the p38 MAPK signaling pathway and activation of NF-κB.     

Noxa/HSP27 complex delays degradation of ubiquitylated IkBα in airway epithelial cells to reduce pulmonary inflammation

IFN-γ is known as a pro-inflammatory cytokine, but can also block inflammation in certain chronic diseases although the underlying mechanisms are poorly understood. We found that IFN-γ rapidly induced Noxa expression and that extent of inflammation by repeated house dust mite exposure was enhanced in noxa^−/− compared with noxa^+/+ mice. Noxa expression blocked transforming necrosis factor alpha (TNF-α)-induced nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and the production of pro-inflammatory cytokines. Noxa did not affect TNF-α-induced IκBα phosphorylation but the degradation of 48-chain-ubiquitylated IκBα. The Cys25 of Noxa was cross-linked with Cys137 of phospho-HSP27 and both proteins were required for blocking the degradation of ubiquitylated IκBα. Because phospho-HSP27 is present in airway epithelial cells and not in fibroblasts or thymocytes, we generated transgenic mice that inducibly expressed Noxa in airway epithelia. These mice showed protection from allergen-induced inflammation and mucous cell metaplasia by blocking nuclear translocation of NF-κB. Further, we identified a Noxa-derived peptide that prolonged degradation of 48-chain-ubiquitylated IκBα, blocked nuclear translocation of NF-κB, and reduced allergen-induced inflammation in mice. These results suggest that the anti-inflammatory role of the Noxa protein may be restricted to airway epithelial cells and the use of Noxa for therapy of chronic lung diseases may be associated with reduced side effects.     

抗氧化剂和NF-κB对大肠癌细胞IL-8表达的作用及机制

目的：探讨NF-κB在大肠癌细胞IL-8诱导表达中的作用及抗氧化剂对大肠癌细胞IL-8诱导表达的影响及其机制。 方法： IL-8 mRNA表达采用逆转录/聚合酶链反应(RT/PCR)检测，培养上清IL-8蛋白含量用ELISA检测，EMSA法测定细胞核内NF-κB结合活性。 结果： 抗氧化剂可阻断大肠癌细胞培养体系TNF-α诱导的IL-8生成及IL-8 mRNA的表达, TNF-α可诱导大肠癌细胞NF-κB的激活并被抗氧化剂阻断。 结论： TNF-α诱导的大肠癌细胞IL-8基因和蛋白表达依赖于NF-κB的激活；抗氧化剂可通过抑制NF-κB的活化而阻断IL-8基因和蛋白的诱导表达。