Advances in understanding the role of IKKβ in tumorigenesis and its inhibitors / 中国临床药理学与治疗学

In recent years, the role of inhibitor kappa B kinaseβ (IKKβ) in the process of tumorigenesis has gradually been elucidated. IKK is involved in tumor cell proliferation and survival by acting on multiple molecular pathways. Inhibition of IKKβ has been identified as a promising treatment for cancer. Researchers have developed a series of IKKβ inhibitors and found that they can effectively inhibit tumor growth, but no IKKβ inhibitors have been used clinically to treat cancer. We discuss progress in understanding the role of IKKβ in tumorigenesis and review the recent development of main inhibitors of IKKβ.

Nitric Oxide Inhibits NF-κB-mediated Survival Signaling: Possible Role in Overcoming TRAIL Resistance.

BACKGROUND/AIM: Chemoresistance is a major consequence of multicycle chemotherapy and can be attributed to constitutive activation of pro-survival signaling pathways. Nitric oxide is a ubiquitous signaling molecule which has been shown to inhibit several pathways involved with survival signaling in cancer cells. We have previously demonstrated the anti-tumor activity of a nitric oxide-donor, nitrosylcobalamin (NO-Cbl), mediated by increased expression of tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) and its receptors in human tumors. We also demonstrated that a functional Apo2L/TRAIL receptor is necessary for the induction of cell death by NO-Cbl and the Apo2L/TRAIL death receptor DR4 (TRAIL R1) is S-nitrosylated. The aim of the study was to examine the effects of nitric oxide (NO) on nuclear factor kappa B (NF-κB) and determine whether nitric oxide could sensitize drug-resistant melanomas to Apo2L/TRAIL via inhibition of NF-κB or inhibitor kappa B kinase (IKK). MATERIALS AND METHODS: Antiproliferative effects of NO-Cbl and Apo2L/TRAIL were assessed in malignant melanomas and non-tumorigenic melanocyte and fibroblast cell lines. Athymic nude mice bearing human melanoma A375 xenografts were treated with NO-Cbl and Apo2L/TRAIL. Apoptosis was measured by the TUNEL assay. The activation status of NF-κB was established by assaying luciferase reporter activity, the phosphorylation status of IκBα, and in vitro IKK activity. RESULTS: NO-Cbl sensitized Apo2L/TRAIL-resistant melanoma cell lines to growth inhibition by Apo2L/TRAIL, but had minimal effect on normal cell lines. NO-Cbl and Apo2L/TRAIL exerted synergistic anti-tumor activity against A375 xenografts. NO-Cbl suppressed Apo2L/TRAIL- and TNF-α-mediated activation of a transfected NF-κB-driven luciferase reporter. NO-Cbl inhibited IKK activation, characterized by decreased phosphorylation of IκBα. CONCLUSION: NO-Cbl treatment rendered Apo2L/TRAIL-resistant malignancies sensitive to the anti-tumor effects of Apo2L/TRAIL in vitro and in vivo. The use of nitric oxide to inhibit NF-κB and potentiate the effects of chemotherapeutic agents, such as Apo2L/TRAIL, represents a promising anti-cancer combination based on recent clinical investigations of anti-TRAIL antibodies for cancer treatment strategies.

The anti-inflammatory and anti-nociceptive effects of Korean black ginseng.

BACKGROUND: Different processing conditions alter the ginseng bioactive compounds, promoting or reducing its anti-inflammatory effects. We compared black ginseng (BG) - that have been steamed 5 times - with red ginseng (RG). HYPOTHESIS/ PURPOSE: To compare the anti-inflammatory activities and the anti-nociceptive properties of RG and BG. METHODS: Nitric Oxide (NO) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay, quantitative Reverse Transcriptase-Polymerase Chain Reaction (qRT-PCR), western blot, xylene-induced ear edema, carrageenan-induced paw edema RESULTS: The ginsenoside contents were confirmed using high-performance liquid chromatography (HPLC) and has been altered through increased processing. The highest concentration of these extracts inhibited NO production to near-basal levels in lipopolysaccharide (LPS)-stimulated RAW 264.7 without exhibiting cytotoxicity. Pro-inflammatory cytokine expression at the mRNA level was investigated using qRT-PCR. Comparatively, BG exhibited better inhibition of pro-inflammatory mediators, iNOS and COX-2 and pro-inflammatory cytokines, IL-1ß, IL-6 and TNF-α. Protein expression was determined using western blot analysis and BG exhibited stronger inhibition. Xylene-induced ear edema model in mice and carrageenan-induced paw edema in rats were carried out and tested with the effects of ginseng as well as dexamethasone and indomethacin - commonly used drugs. BG is a more potent anti-inflammatory agent, possesses anti-nociceptive properties, and has a strong potency comparable to the NSAIDs. CONCLUSION: BG has more potent anti-inflammatory and anti-nociceptive effects due to the change in ginsenoside component with increased processing.

The IL-1RI Co-Receptor TILRR (FREM1 Isoform 2) Controls Aberrant Inflammatory Responses and Development of Vascular Disease.

Expression of the interleukin-1 receptor type I (IL-1RI) co-receptor Toll-like and interleukin-1 receptor regulator (TILRR) is significantly increased in blood monocytes following myocardial infarction and in the atherosclerotic plaque, whereas levels in healthy tissue are low. TILRR association with IL-1RI at these sites causes aberrant activation of inflammatory genes, which underlie progression of cardiovascular disease. The authors show that genetic deletion of TILRR or antibody blocking of TILRR function reduces development of atherosclerotic plaques. Lesions exhibit decreased levels of monocytes, with increases in collagen and smooth muscle cells, characteristic features of stable plaques. The results suggest that TILRR may constitute a rational target for site- and signal-specific inhibition of vascular disease.

Cis- and Trans-gnetin H from Paeonia suffruticosa suppress inhibitor kappa B kinase phosphorylation in LPS-stimulated human THP-1 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: The inflammatory response is an important mechanism in host defense; however, overstimulation and chronic inflammation are involved in many important human diseases. Currently, tumor necrosis factor-alpha blockers such as infliximab and adalimumab along with methotrexate are used in cases of severe and chronic disease. However, there are severe side effects and limitations associated with these treatments. Cis- and trans-gnetin H are compounds isolated from the seeds of Paeonia suffruticosa, a medicinal plant used in traditional Chinese medicine for the treatment of many conditions, including inflammatory diseases. In this study, we investigated possible anti-inflammatory mechanisms of cis- and trans-gnetin H against LPS-stimulated human THP-1 cells. MATERIAL AND METHODS: PMA-differentiated THP-1 cells were pretreated with increasing concentrations of cis- and trans-gnetin H with or without LPS. Following treatment, cytotoxicity and the TNF-α, IL-1ß, and IL-8 response were measured. We also characterized the nuclear translocation of NF-κB subunit p65 (RelA) by immunofluorescence and then investigated NF-κB activation by measuring the phosphorylation of NF-κB mediators, IKK-ß, IκB α, and p65 by western blotting. RESULTS: We found that cis- and trans-gnetin H significantly inhibited the cytokine response in a concentration-dependent manner without affecting cell viability. Cis- and trans-gnetin H effectively inhibited nuclear translocation of p65 and phosphorylation of IKK-ß, IκB α, and p65. While both compounds showed promising anti-inflammatory effects, trans-gnetin H was determined to be more effective in suppressing cytokine responses. CONCLUSION: We demonstrated that cis- and trans-gnetin H suppress cytokine response in LPS-stimulated THP-1 cells by preventing activation of key signaling molecules, IKK-ß, IκB α, and p65, involved in the NF-κB pathway and suggest the use of cis- and trans-gnetin H in potential therapies for conditions and diseases associated with chronic inflammation.

Tetracyclines downregulate the production of LPS-induced cytokines and chemokines in THP-1 cells via ERK, p38, and nuclear factor-κB signaling pathways.

Recent reports have shown that antibiotics such as macrolide, aminoglycoside, and tetracyclines have immunomodulatory effects in addition to essential antibiotic effects. These agents may have important effects on the regulation of cytokine and chemokine production. However, the precise mechanism is unknown. This time, we used Multi Plex to measure the production of cytokines and chemokines following tetracycline treatment of lipopolysaccharide (LPS)-induced THP-1 cells. The signaling pathways were investigated with Western blotting analysis. Three tetracyclines significantly suppressed the expression of cytokines and chemokines induced by LPS. Minocycline (50 µg/ml), tigecycline (50 µg/ml), or doxycycline (50 µg/ml) were added after treatment with LPS (10 µg/ml). Tumor necrosis factor-α was downregulated to 16%, 14%, and 8%, respectively, after 60 min compared to treatment with LPS without agents. Interleukin-8 was downregulated to 43%, 32%, and 26% at 60 min. Macrophage inflammatory protein (MIP)-1α was downregulated to 23%, 33%, and 16% at 120 min. MIP-1ß was downregulated to 21%, 11%, and 2% at 120 min. Concerning about signaling pathways, the mechanisms of the three tetracyclines might not be the same. Although the three tetracyclines showed some differences in the time course, tetracyclines modulated phosphorylation of the NF-κB pathway, p38 and ERK1/2/MAPK pathways, resulting in inhibition of cytokine and chemokine production. In addition, SB203580 (p38 inhibitor) and U0126 (ERK1/2 inhibitor) significantly suppressed the expression of TNF-α and IL-8 in LPS-stimulated THP-1 cells. And further, the NF-κB inhibitor, BAY11-7082, almost completely suppressed LPS-induced these two cytokines production. Thus, more than one signaling pathway may be involved in tetracyclines downregulation of the expression of LPS-induced cytokines and chemokines in THP-1 cells. And among the three signaling pathways, NF-κB pathway might be the dominant pathway on tetracyclines modification the LPS-induced cytokines production in THP-1 cells. In general, minocycline and doxycycline suppressed the production of cytokines and chemokines in LPS-stimulated THP-1 cell lines via mainly the inhibition of phosphorylation of NF-κB pathways. Tigecycline has the same structure as the other tetracyclines, however, it showed the different properties of cytokine modulation in the experimental time course.

Microwave-assisted synthesis of cyclic phosphopeptide on solid support.

Phosphopeptides are important tools for studying intracellular signal transduction events in vitro and in vivo and are also potential drugs due to their direct competition with phosphoprotein recognition elements. Cyclization has been demonstrated to improve peptide selectivity, metabolic stability, and bioavailability. However, cyclic phosphopeptide synthesis may not be straightforward due to the sterically hindered phosphorylated side-chain amino acid derivatives. One option to overcome this hurdle is to use microwave-assisted synthesis, which has been shown to increase efficiency and reduce synthesis time. Herein, a detailed protocol is provided for synthesizing cyclic phosphopeptides using automated microwave. The overall synthesis duration was reduced and yields increased compared with a manual conventional method. This method provides a general, fast and facile way to synthesize cyclic peptides, demonstrating the synthesis of cyclic phosphorylated peptides which are known to be among the most challenging to produce.

Humic acid in drinking well water induces inflammation through reactive oxygen species generation and activation of nuclear factor-κB/activator protein-1 signaling pathways: a possible role in atherosclerosis.

Humic acid (HA) has been implicated as one of the etiological factors in the peripheral vasculopathy of blackfoot disease (BFD) in Taiwan. However, the underlying pathophysiological mechanisms of BFD are not well defined. In this study, we used an in vitro and in vivo model, in which HA (25-200µg/mL) activated macrophages to produce pro-inflammatory molecules by activating their transcriptional factors. HA exposure induced NO and PGE2 production followed by induction of iNOS and COX-2 through NF-κB/AP-1 transactivation in macrophages. In addition, the production of TNF-α and IL-1ß was significantly increased by HA. Moreover, HA-induced iNOS and COX-2 expression were down-regulated by the NF-κB and AP-1 inhibitors pyrrolidine dithiocarbamate (PDTC) and Tanshinone, respectively. Furthermore, generations of ROS and nitrotyrosine, as well as activation of the AKT and MAPKs signaling cascades were observed after HA exposure. Specifically, HA-induced NF-κB activation was mediated by ROS and AKT, and that HA-induced AP-1 activation was mediated by JNK and ERK. Notably, HA-mediated AKT, JNK, and ERK activation was ROS-independent. The inflammatory potential of HA was correlated with increased expression of HO-1 and Nrf2. Furthermore, an in vivo study confirms that mice exposed to HA, the serum levels of TNF-α and IL-1ß was significantly increased in a dose-dependent manner. This report marks the first confirmation that environmental exposure of HA induces inflammation in macrophages, which may be one of the main causes of early atherogenesis in blackfoot disease.

(E)-3-(3,4-Dimethoxyphenyl)-1-(5-hydroxy-2,2-dimethyl-2H-chromen-6-yl)prop-2-en-1-one ameliorates the collagen-arthritis via blocking ERK/JNK and NF-κB signaling pathway.

Our previous report has shown a natural pyranochalcones-derived compound, (E)-3-(3,4-Dimethoxyphenyl)-1-(5-hydroxy-2,2-dimethyl-2H-chromen-6-yl)prop-2-en-1-one (5b), that exerted protection against carrageenan-induced hind paw edema and adjuvant-induced arthritis. In this study, collagen-induced arthritis (CIA) model was used to further examine the anti-arthritic effects of 5b in vivo; the underlying molecular mechanisms of action were also investigated using a murine monocytic cell line, RAW264.7 cells. Here we showed that oral administration of 5b (20mg/kg) significantly suppressed the progression of arthritis. Improvement in disease severity was accompanied by inhibition of CD68-positive cells in knee joint and reduced pro-inflammatory cytokines TNF-α, IL-1ß and IL-6 in serum. In vitro, 5b suppressed expressions of iNOS, cyclooxygenase-2 (COX-2), TNF-α, IL-6 and IL-1ß as well as productions of nitric oxide (NO) and prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-treated macrophages. This compound also significantly suppressed LPS-induced NF-κB activation, including phosphorylation of I-κB, degradation of I-κB, and nuclear translocation of p65 and p50. Treatment with 5b also blocked LPS-induced expression of TLR4 remarkably, suppressed degradation of IRAKs and phosphorylations of JNK and ERK, but had little effect to p38 kinase activation. These findings indicated that 5b might be a therapeutic agent for rheumatoid arthritis, and exerted an anti-inflammatory effect mainly through mediating TLR4, NF-κB and ERK/JNK signaling pathways in monocytes.

Effects of dexamethasone on expression of nuclear factor kappa B/inhibitor kappa B alpha and apoptosis of lens epithelial cells / 中华实验眼科杂志

Background Researches demonstrated that the long-term application of glucocorticoids can induce cataract. However, its molecular mechanism is unclear. Objective Present study was to investigate the effects of dexamethasone on the regulation of nuclear factor kappa B( NF-κB)/ inhibitor kappa B alpha( IκBα) line on human lens epithelial cells (LECs) and the LECs apoptosis. Methods Human LECs line(HLE2B3) were cultured and passaged in DMEM containing 20% fetal bovine serum and treated by different concentrations of dexamethasone(0. 01,0. 1,1,10,100 μmol/L) for 24,36 and 48 hours respectively. The LECs cultured in free-serum DMEM without dexamethasone were as blank control group. The expressions of IκBo: in the LECs were examined by reverse transcription polymerase chain reaction ( RT-PCR) and Western blot, and the expressions of NF-κB neucleoprotein in LECs were detected by Western blot after exposure to dexamethasone. The apoptosis rate of LECs was determined by flow cytometer. Results Agarose gel electrophoresis showed that the amplified gene fragment was coincident to designed one. The expressing level of NF-κB neucleoprotein in LECs was significantly lowed with the increase of dexamethasone concentration ( F = 36. 077 , P = 0. 004 ) , and that of IkBo: was evidently ascended ( F = 35. 741 ,P = 0. 002). In the same concentration of dexamethasone group,the expression of NF-κB in LECs showed the considerable alteration in different duration after treated of dexamethasone with the lowest expressing level in 36 hours, and significant differences were found in the expressing level between 24 hours and 36 hours ( P = 0. 002) and between 24 hours and 48 hours (P = 0. 01). The differences of expression of IκBá in LECs appeared the same pattern to NF-κB neucleoprotein. Flow cytometry showed that the apoptosis rate of LECs was obviously enhanced after action of dexamethasone in a dose-dependent manner, showing a significant difference among different groups ( F = 73. 261, P = 0.001). Conclusion It is implied that dexamethasone results in the pathogenesis and development of glucocorticoid cataract by up-regulating the expression of IκBα in LECs and suppressing the activity of NF-κB and herein induce the apoptosis of LECs at concentration-and time-dependent manner. This might be one of cellular and biological mechanisms of glucocorticoid cataract formation.

Effects of methylprednisolone on pneumocyte apoptosis during pulmonary ischemia/reperfusion injury in rats / 医学研究生学报

Objective:To investigate the effects of methylprednisolone(MP)on pneumocyte apoptosis during lung ischemia/reperfusion injury in rats and to study the possible role of MP in pneumocyte apoptosis.Methods:Forty-two male Sprague-Dawley rats used for unilateral lung ischemia/reperfusion model were randomly divided into three groups:sham operation group(Sh group),ischemia/reperfusion group(I/R group),and methylprednisolone group(MP group).Each group has two subgroups of three hours and six hours.Apoptosis rate in lung tissue was detected by the way of Annexin-V-PI in flow cytometer.Expression of I?B-? in lung was observed by immunohistochemical stain.The index of quantitative assessment of histological lung injury(IQA),the wet to dry weight ratio(W/D),the pathological and ultrastructure changes of lung tissue were measured.Results:Apoptosis rate,W/D,IQA of lung tissue were significantly higher in I/R group than which in Sh group(P

Inhibitory effects of intensive insulin on myocardium expression of tumor necrosis factor alpha in severely burnt rats / 解放军医学杂志

Objective To investigate the inhibitory effects of intensive insulin on myocardium expression of tumor necrosis factor alpha(TNF-?)in severely burnt rats and its correlative mechanism.Methods In eighteen SD rats the right jugular vein and the left ventricle were cathetetized,and were divided into three groups randomly:(1)the sham burn group,the rats were treated by sham burn;(2)the burn group,the rats were inflicted with 30%TBSA Ⅲ degree burn,and then given fluid resuscitation routinely;(3)the intensive insulin group,the rats received intensive insulin treatment after burn,and the liquid volume given was equal to the burn group.The level of plasma glucose contents,the left ventricular systolic pressure(LVSP)and left ventricular end-diastolic pressure(LVEDP)were recorded at 1,2,3,4,5,6h after burn,and animals were sacrificed at 6 hours after burn.The level of TNF-? in myocardium tissue was assayed by ELISA,and mRNA expression was determined by real-time PCR.Western blot was used to detect I?B? phosphorylation and degradation in left ventricle tissue.Meanwhile,burn serum-challenged cardiomyocytes were also used to detect the levels of insulin and LY294002,a specific insulin activation inhibitor,on the phosphorylation of I?B?.Results The animals showed stress hyperglycemia after burns,the function of heart was damaged(LVSP degraded and LVEDP increased),the level of TNF and the expression of mRNA in the myocardium increased apparently,I?B? phosphorylation and degradation increased in left ventricle tissue and burn serum-challenged cardiomyocytes.Given the intensive insulin treatment to keep the blood glucose level between 4.5 to 5.2 mmol/L,the function of heart was significantly improved,the level of TNF-? was apparently lowered,and the I?B? phosphorylation and degradation were significantly decreased.LY294002 could abolish the inhibitory effect of insulin,and it acted on the I?B? phosphorylation on burn serum-challenged cardiomyocytes model.Conclusion Intensive insulin may decrease the activation of NF-?B through diminishing the I?B? phosphorylation and degradation,which inhibit the transcription and expression of TNF-? in myocardial cell,and improve the heart function accordingly.