Triggering of NF‐κB in cytokine‐matured human DCs generates superior DCs for T‐cell priming in cancer immunotherapy

Understanding the signaling that governs the immunogenicity of human dendritic cells (DCs) is a prerequisite for improving DC‐based therapeutic vaccination strategies, in which the ability of DCs to induce robust and lasting Ag‐specific CTL responses is of critical importance. Cytokine‐matured DCs are regularly used, but to induce memory‐type CTLs, they require additional activation stimuli, such as CD4⁺ T‐cell help or TLR activation. One common denominator of these stimuli is the activation of NF‐κB. Here, we show that human monocyte‐derived, cytokine cocktail‐matured DCs transfected with constitutively active mutants of IκB kinases (caIKKs) by mRNA electroporation, further upregulated maturation markers, and secreted enhanced amounts of cytokines, including IL‐12p70, which was produced for more than 48 h after transfection. Most importantly, cytotoxic T cells induced by caIKK‐transfected DCs combined high CD27 expression, indicating a more memory‐like phenotype, and a markedly enhanced secondary expandability with a high lytic capacity. In contrast, CTLs primed and expanded with unmodified cytokine cocktail‐matured DCs did not maintain their proliferative capacity upon repetitive stimulations. We hypothesize that “designer” DCs expressing constitutively active IκB kinases will prove highly immunogenic also in vivo and possibly emerge as a new strategy to improve the clinical efficacy of therapeutic vaccinations against cancer and other chronic diseases.     

抑制核因子-κB对糖尿病肾病的作用

目的　研究抑制核因子 κB(NF κB)活性对糖尿病肾病 (DN)及糖尿病大鼠肾组织纤维连接蛋白 (FN)mRNA表达的作用。方法　将纯种雄性Wistar大鼠分为 :A组为正常对照组 (1 1只 ) ,B组为糖尿病无干预组 (1 1只 ) ,C组为吡咯烷二硫基甲酸酯 (PDTC ,NF κB抑制剂 )干预组 (9只 )。饲养 1 8周后 ,以电泳迁移率变动分析技术检测肾组织NF κB活性 ,透射电镜检测肾小球基底膜厚度及系膜基质密度 (系膜基质面积 /系膜面积 ) ,逆转录PCR检测FNmRNA表达 ,收集 2 4h尿测定尿白蛋白排泄率 (UAE)。结果　NF κB活性在B组大鼠肾组织 [(1 85± 0 54)× 1 0 6 ]显著高于A组 [(0 0 7± 0 1 1 )×1 0 6 ,P <0 0 1 ] ,C组 [(0 2 5± 0 2 5)× 1 0 6 ]显著低于B组 (P <0 0 1 )。B组与A组比较 ,UAE[(2 1 8±1 98)mgvs (0 41± 0 47)mg ,P <0 0 1 ]、肾小球基底膜厚度 [(531 6± 1 0 7 6)nmvs (31 2 4± 2 5 4)nm ,P<0 0 1 ]及系膜基质密度 [(56 41± 6 78)vs (33 95± 5 2 2 ) ,P <0 0 1 ]均有显著差异 ;UAE(0 56± 0 72 )mg、肾小球基底膜厚度 (31 5 8± 2 1 4)nm及系膜基质密度 (37 97± 7 37)在C组均显著低于B组 (P值均 <0 0 1 )。FNmRNA表达在B组大鼠肾组织 (0 73± 0 2 6)显著高于A组 (0 31± 0     

Smac mimetic primes apoptosis-resistant acute myeloid leukaemia cells for cytarabine-induced cell death by triggering necroptosis

The prognosis for patients with acute myeloid leukaemia (AML) is still poor, thus calling for novel treatment strategies. Here, we report that the small-molecule Smac mimetic BV6, which antagonizes Inhibitor of Apoptosis (IAP) proteins, acts in concert with cytarabine (AraC) to trigger cell death in AML cells in a highly synergistic manner (combination index 0.02–0.27). Similarly, BV6 cooperates with AraC to trigger cell death in primary AML samples, underscoring the clinical relevance of our findings. Molecular studies reveal that the TNFα-blocking antibody Enbrel significantly reduces BV6/AraC-induced cell death, demonstrating that an autocrine/paracrine TNFα loop mediates cell death. Furthermore, BV6 and AraC synergize to induce loss of mitochondrial membrane potential, caspase activation and DNA fragmentation, consistent with apoptotic cell death. Nevertheless, the caspase inhibitor zVAD.fmk fails to protect against BV6/AraC-induced cell death. Intriguingly, this cell death upon caspase inhibition is significantly reduced by pharmacological inhibition of two key components of necroptosis signaling, i.e. by RIP1 kinase inhibitor Necrostatin-1 or MLKL inhibitor NSA. Thus, BV6 sensitizes AML cells to AraC-induced cell death and overcomes apoptosis resistance by triggering necroptosis as alternative form of cell death. These findings have important implications for Smac mimetic-based strategies to bypass apoptosis resistance of AML.     

Astilbin protects diabetic rat heart against ischemia–reperfusion injury via blockade of HMGB1-dependent NF-κB signaling pathway

Astilbin, a flavonoid compound was isolated from the rhizome of Smilax china L. In this study, we investigated the anti-myocardial ischemia and reperfusion (I/R) injury effect of Astilbin on diabetic rats in vivo and elucidated the potential mechanism in vitro. The results showed that Astilbin significantly attenuated hypoxia-induced cell injury in a concentration-dependent manner. Treatment of H9c2 cells with Astilbin at 15 μM blocked nuclear factor kappaB (NF-κB) phosphorylation by blocking High-mobility group box protein 1 (HMGB1) expression. Treatment of diabetic rats with Astilbin by intravenous injection (i.v.) at a single dose of 50 mg/kg protected the rats from myocardial I/R injury as indicated by decreasing infarct volume, improving hemodynamics and reducing myocardial damage, and also lowered serum levels of pro-inflammatory factors, reduced HMGB1 and phosphorylated NF-κB expression in ischemic myocardial tissue from diabetic rats. Additionally, treatment of diabetic rats with Astilbin at dose of 50 mg/kg by i.v. for continuous 14 days attenuated cardiac remodeling in the model myocardial I/R injury. These protective effects suggested that Astilbin might be due to block of the myocardial inflammatory cascade via the HMGB1-dependent NF-κB signaling pathway.     

EP4 receptor signalling in immature B cells involves cAMP and NF-κB dependent pathways

Objectives Delineation of EP4 receptor signalling properties in immature B cells. Methods WEHI 231 cells were used as a model of immature B lymphocytes. The effects of PGE2, EP4 receptor antagonist, EP4 receptor agonist, forskolin and adenylate cyclase inhibitor on proliferation of WEHI 231 cells were examined by MTS assay. Cyclic adenosine monophosphate (cAMP) levels were examined by ELISA, whereas phosphorylation of vasodilator‐stimulated phosphoprotein (VASP), kinase, extracellular signal‐regulated kinase1/2, IκB‐α and nuclear factor (NF)‐κB subunit p105 were subjected to Western blot analysis. Translocation of NF‐κB subunit p65 and EPRAP (EP4 receptor associated protein) was examined by fluorescence microscopy. Levels of early growth response factor (Egr)‐1 mRNA were determined by quantitative PCR. Key findings We identified the EP4 receptor as the principal molecule mediating the growth‐suppressive effect of prostaglandin E2 in WEHI 231 cells. EP4 receptor activation results in cAMP formation and the activation of protein kinase A, NF‐κB1 p105 subunit stabilization and inhibition of IκBα phosphorylation, followed by the accumulation of NF‐κB p65 subunit in the cell cytoplasm, whereas the activation of PI3K is not involved in EP4 receptor signalling. Elevation of cAMP and inhibition of NF‐κB activation are two possible mechanisms by which the EP4 receptor inhibits the proliferation of immature B lymphocytes. Conclusions Modulation of the EP4 receptor on immature B lymphocytes provides important insight into the observed action of PGE2 and opens new possibilities for the development of therapies for autoimmune diseases, leukaemia and lymphomas.     

低频重复经颅磁刺激对颞叶癫痫大鼠海马NF-κB及COX-2表达的影响

目的 研究低频重复经颅磁刺激(rTMS)对颞叶癫痫模型大鼠海马核转录因子κB(NF-κB)和环争化酶2(COX-2)表达的影响,进而从炎症反应角度探讨rTMS治疗癫痫的可能机制.方法 30只雄性SD大鼠随机分为颞叶癫痫刺激组(TIE+rTMS)、颢叶癫痫假刺激组(TLE+s-rTMS)和生理盐水对照组(NS),每组10只.利用立体定位仪向大鼠海马CA,区微量注射海人酸(KA)制备颞叶癫痫模型,对照组于同部位注射等量生理盐水.刺激组连续接受rTMS治疗10d.采用免疫组织化学染色、蛋白质印迹法(western blotting)研究大鼠海马NF-κBp65和COX-2表达情况.结果 与生理盐水对照组大鼠比较,造模后大鼠海马组织中NF-κBp65和COX-2表达明显增强NF-κBp65核移位增多,差异均有统计学意义(P＜0.05),TLE+rTMS组大鼠海马组织中NF-κBp65和COX-2表达较TLE+s-rTMS组明显降低,NF-κBp65核移位减少,差异均有统计学意义(P＜0.05).结论 rTMS可能通过降低癫痫大鼠海马NF-κB和COX-2的表达,阻止NF-κB核移位,从而抑制炎症反应发挥抗癫痫作用.     

PARP-1与NF-κB在卵巢上皮性肿瘤组织中的表达及意义

目的:研究卵巢上皮性肿瘤组织中聚腺苷酸二磷酸核糖聚合酶-1(PARP-1)、核转录因子κB(NF-κB)的表达及意义.方法:采用免疫组织化学SP法检测10例正常卵巢组织、30例卵巢良性肿瘤、30例卵巢交界性肿瘤和50例卵巢癌原发灶中的PARP-1和NF-κBp65蛋白表达.结果:①PARP-1蛋白和NF-κBp65蛋白在卵巢癌组织中阳性表达率均高于卵巢交界性肿瘤、卵巢良性肿瘤和正常卵巢组织,差异均有统计学意义(P＜0.05);而两者的阳性表达率在卵巢交界性肿瘤、卵巢良性肿瘤及正常卵巢组织间比较,差异均无统计学意义(P＞0.05).②PARP-1和NF-κBp65蛋白与卵巢癌的病理分级、临床分期和有无淋巴结转移有关(P＜0.05).③卵巢癌组织中PARP-1与NF-κBp65表达呈正相关(r=0.596,P＜0.05).结论:PARP-1和NF-κB在卵巢癌组织中过表达,与卵巢癌的发生、发展有关.PARP-1可能通过作用于NF-κB促进卵巢上皮性肿瘤细胞的恶性转化.     

Interleukin 6 augments lung cancer chemotherapeutic resistance via ataxia‐telangiectasia mutated/NF‐kappaB pathway activation

Although it is known that ataxia‐telangiectasia mutated (ATM) and interleukin 6 (IL‐6) contribute to multiple drug resistance (MDR) in tumor chemotherapy, the exact role of ATM activation in MDR resulting from increased IL‐6 expression is still unclear. In the present study, we demonstrate that the activation of the ATM‐NF‐kappaB pathway, resulting from increased IL‐6 expression, plays a central role in augmented chemoresistance in lung cancer cell lines. This result was supported by the increased expressions of Bcl‐2, Mcl‐1, Bcl‐xl, and the upregulation of MDR‐associated protein ABCG2. The higher level of IL‐6 reveals not only higher ATM/NF‐kappaB activity but also increased expressions of ABCG2, Bcl‐2, Mcl‐1 and Bcl‐xl. Most importantly, lung cancer cells themselves upregulated IL‐6 secretion by activating the p38/NF‐kappaB pathway through treatment with cisplatin and camptothecin. Taken together, these findings demonstrate that chemotherapeutic agents increase IL‐6 expression, hence activating the ATM/NF‐kappaB pathway, augmenting anti‐apoptotic protein expression and contributing to MDR. This indicates that both IL‐6 and ATM are potential targets for the treatment of chemotherapeutic resistance in lung cancer.