Rel/NF-κB与神经系统疾病

自从 1 986年真核细胞核转录因子Ｒｅｌ/ＮＦ κＢ被发现以来 ,对它的研究就一直方兴未艾。Ｒｅｌ/ＮＦ κＢ参与一系列病理和生理过程反应 ,如免疫反应、炎症反应等 ,在细胞的生长、分化、粘附、凋亡等过程中也具有十分重要的作用。1 .Ｒｅｌ/ＮＦ κＢ信号转导通路在静息状态时 ,Ｒｅｌ/ＮＦ κＢ与抑制蛋白ＩκＢ结合 ,抑制其核转位信号 ,使之以无活性形式存在于胞浆中 ;胞外刺激信号如活性氧介质 (ＲＯＩ)、细胞因子、神经递质、病毒、ＵＶ、内质网超载等通过转导激活ＩＫＫ上游激酶ＭＥＫＫ 1或ＮＩＫ而使ＩＫＫ复合物活化 ,在酪蛋白激…     

NF-κB与疾病

NF－κB是一种多极性基因调控性能的转录因子,能够激活若干个炎症反应、机体免疫反应及多种细胞因子的基因转录过程,从而控制它们的生物合成。本文综述了近年来国外对NF－κB的研究进展,对NF－κB的结构组成、激活途径、生物学功能及其与多种疾病的关系作一介绍。     

CXCR4和NF-κB在子宫内膜癌中的表达及其临床意义

目的:检测CXCR4和NF-κB在子宫内膜癌中的表达并探讨其在肿瘤发生发展中的作用机制。方法:用免疫组织化学SP法测定不同子宫内膜组织中CXCR4和NF-κB的蛋白质表达情况,并分析两者表达的相关性,所选标本包括20例正常子宫内膜蜡块、30例子宫内膜不典型增生石蜡标本、60例子宫内膜癌。结果:CXCR4的阳性表达率在子宫内膜癌中为73.33%、在不典型增生子宫内膜中为43.33%,在正常子宫内膜中为25.00%;NF-κB在子宫内膜癌、不典型增生子宫内膜和正常子宫内膜的阳性表达率依次为:63.33%、36.67%、15.00%,差异均具有统计学意义(P0.05)。CXCR4和NF-κB两个因子与淋巴结有无转移、年龄、肌层浸润情况无相关性,但与癌组织分化级别相关。两个因子在子宫内膜癌中的表达具有明显的相关性(r=0.341,P=0.008)。结论:CXCR4和NF-κB在子宫内膜癌组中的阳性表达率明显升高,且两者成正相关,两个因子在诱发子宫内膜癌的发生中可能起协同作用。     

NF-κB的结构功能及其与疾病的关系

NF-κB蛋白家族在哺乳动物的生长发育和免疫反应中具有重要作用。NF—κB信号传导途径的改变会引起多种炎性疾病和肿瘤的发生。该主要介绍近些年来在NF—κB及其相关蛋白的主要结构和生物学功能方面的研究进展,同时揭示NF—κB蛋白家族与炎症、肿瘤疾病之间存在的关系,探讨NF—κB相关蛋白抑制剂的应用。     

NF-κB“圈套”抑制PC12细胞中NF-κB活性模型的建立

目的:观察NF-κB圈套(κB-decoy)寡核苷酸对LPS诱导PC12细胞中NF-κB活化的抑制过程,建立κB-de-coy抑制NF-κB活化的细胞模型。方法:将培养于6孔板的PC12细胞进行分组转染,实验组:LF2000+κB-decoy(6μg/well);对照组:LF2000+错配-decoy;正常组:LF2000。转染48h后,加入LPS(200ng/ml),作用0.5～4h。分别用免疫细胞化学染色和Westernblot方法检测PC12细胞内NF-κB的表达及活化。结果:与正常组相比较,转染错配-decoy的对照组细胞,随着LPS刺激时间的延长,NF-κB的表达和活化明显增加(P0.01),2～4h达到高峰;与对照组相比较,转染κB-decoy实验组的PC12细胞,随着LPS刺激时间的延长,NF-κB的表达处于较稳定水平,在LPS刺激的各时间点中明显低于对照组(P0.01)。结论:κB-decoy可以降低生理状态下PC12细胞内NF-κB的正常表达水平,抑制病理状态下NF-κB的活化。     

糖尿病诱导serpinE1分泌增多对心肌细胞NF-κB核易位及凋亡的影响

摘要 目的：探讨糖尿病诱导serpinE1分泌增多是否引起心肌细胞NF-κB核易位及凋亡。方法：8周龄C57BL/6J小鼠随机分为对照组和糖尿病组,糖尿病模型应用链脲佐菌素腹腔注射诱导。体外试验中,应用低糖（5.5 mmol/L）及高糖（25 mmol/L）浓度培养基分别处理大鼠心肌H9C2细胞。ELISA法分别检测小鼠血清及细胞培养上清中的serpinE1水平,Western Blot分别检测心脏组织及细胞中 caspase-3、cleaved caspase-3以及细胞浆、细胞核中NF-κB蛋白表达。此外,H9C2细胞分为三组：对照组、serpinE1重组蛋白处理组、JSH-23与serpinE1重组蛋白共同处理组,Western Blot检测上述相同指标。结果：糖尿病小鼠血清及高糖处理的细胞培养上清中serpinE1水平较对照组显著增加(P<0.05)。同对照组相比,细胞核/细胞浆NF-κB、cleaved caspase-3/ caspase-3在糖尿病小鼠心肌组织及H9C2细胞高糖处理组中显著上升(P<0.05)。此外,serpinE1重组蛋白处理后细胞核/细胞浆NF-κB以及cleaved caspase-3/ caspase-3同对照组相比,均显著增加(P<0.05),而JSH-23则减弱了serpinE1的这些效应。结论：糖尿病诱导serpinE1分泌增多促进心肌细胞NF-κB核易位及凋亡。     

PHD1通过下调NF-κB介导的cyclinD1的表达抑制肺癌细胞的生长和增殖

目的:探讨PHD1在肺癌中的功能,并进一步研究其分子机制,为肺癌的治疗寻找新的靶点。方法:选取人肺癌细胞A549,以脂质体为载体一方面过表达PHD1,另一方面合成设计靶向PHD1的siRNA沉默PHD1,利用荧光素酶检测NF-κB的活性,分别用western blot和real-time PCR检测cyclinD1的表达水平。在A549细胞中过量稳定表达带GFP标记的PHD1,流式细胞仪检测细胞周期变化,测量细胞的生长曲线,并将细胞注射到裸鼠皮下观察其成瘤情况。结果:过表达PHD1可明显抑制NF-κB的活性和IκBα的降解,降低cyclin D1的mRNA和蛋白表达水平;而干扰PHD1的表达可显著增加NF-κB的活性,并上调cyclin D1的mRNA和蛋白表达水平,而不影响cyclinE1。过表达IκBαSR可以阻止干扰PHD1引起的cyclinD1 mRNA水平的上调。过表达PHD1可引起细胞周期的停滞,显著抑制细胞的增殖和移植瘤的生长。结论:PHD1可能通过下调NF-κB介导的cyclinD1的表达抑制肺癌细胞的生长和增殖。     

NF-κB与持久炎症及肿瘤发生关系

NF-κB是一种序列特异性转录因子.早先的研究证明其主要功能是参与炎症反应和天然免疫应答.最近的研究发现,某一部位的持久炎症反应将导致NF-κB信号通路组成性持续激活,导致NF-κB靶基因的异常表达,这些基因的异常表达往往与肿瘤的发生、转移、组织浸润以及肿瘤细胞的抗凋亡作用相关.因此,将NF-κB作为靶向分子,抑制其活性已成为肿瘤防治的研究热点和新的思路.     

FABP4对脂多糖诱导Kupffer细胞NF-κB活化和炎症的影响

目的:研究脂肪型脂肪酸结合蛋白(FABP4)对脂多糖(LPS)诱导Kupffer细胞(KCs)NF-κB通路活化和炎症反应的影响。方法:通过梯度离心的方法分离大鼠KCs,按照1×10~5接种于6孔板,贴壁后饥饿24 h,不同浓度脂多糖(LPS,0、5、10和20ng/mL)刺激24 h,提取蛋白和RNA,通过Western-Blot检测NF-κB通路蛋白表达变化,利用荧光定量PCR检测IL-1β和IL-6m RNA表达变化;利用RNAi沉默KCs FABP4表达,通过Western-Blot和荧光定量PCR检测其对LPS诱导NF-κB通路活化的影响;分别利用FABP4细胞因子刺激和慢病毒上调FABP4的表达,通过Western-Blot和荧光定量PCR检测其对KCs NF-κB通路和炎症反应的影响。结果:LPS能够以浓度依赖的方式(0、5、10和20 ng/m L)诱导KCs FABP4 m RNA和蛋白的表达,以20 ng/mL最为明显(P0.05);沉默FABP4可以显著减弱LPS(20 ng/m L)诱导的p-p65和p-IκBα的表达,以及炎症细胞因子IL-1β和IL-6的释放(P0.05);外源性FABP4(10 ng/mL和20 ng/m L)刺激24h后,能够明显诱导p-p65和p-IκBα的表达,促进炎症因子(IL-1β和IL-6)的合成(P0.05);利用慢病毒上调FABP4,可以显著诱导p-p65和p-IκBα的表达以及炎症因子(IL-1β和IL-6)的表达(P0.05),而抗氧化剂NAC(10μM)处理,则显著减弱此效应(P0.05)。结论:FABP4介导了LPS刺激KCs NF-κB通路的活化和炎症反应。     

NF-κB、IκB、IKK在非小细胞肺癌中的表达及意义

目的检测非小细胞肺癌(non-small cell lung cancer,NSCLC)中NF-κB P65、p-IκBα(IκBα磷酸化)、p-IKKβ(IKKβ磷酸化)的表达情况及其与NSCLC临床特征的关系。方法采用免疫组化Elivision法检测NF-κB P65、p-IκBα、p-KKβ在56例NSCLC中表达情况,以20例癌旁组织作为对照。结果在NSCLC中NF-κB P65、p-IκBα、p-IKKβ的表达阳性率分别为83.9%(47/56)、55.7%(31/56)、69.6%(39/56),癌旁组织三者分别为20%(4/20)、25%(5/20)、30%(6/20),NF-κB P65、p-IκBα、p-IKKβ的表达与吸烟史、TNM分期、淋巴结转移相关,差异有统计学意义(P<0.05)。结论 NF-κB P65、p-IκBα、p-IKKβ高表达与NSCLC的发生、发展起着重要作用。     

Differential activation of NF-κB signaling is associated with platinum and taxane resistance in MyD88 deficient epithelial ovarian cancer cells

Development of chemoresistance is a major impediment to successful treatment of patients suffering from epithelial ovarian carcinoma (EOC). Among various molecular factors, presence of MyD88, a component of TLR-4/MyD88 mediated NF-κB signaling in EOC tumors is reported to cause intrinsic paclitaxel resistance and poor survival. However, 50–60% of EOC patients do not express MyD88 and one-third of these patients finally relapses and dies due to disease burden. The status and role of NF-κB signaling in this chemoresistant MyD88^negative population has not been investigated so far. Using isogenic cellular matrices of cisplatin, paclitaxel and platinum-taxol resistant MyD88^negative A2780 ovarian cancer cells expressing a NF-κB reporter sensor, we showed that enhanced NF-κB activity was required for cisplatin but not for paclitaxel resistance. Immunofluorescence and gel mobility shift assay demonstrated enhanced nuclear localization of NF-κB and subsequent binding to NF-κB response element in cisplatin resistant cells. The enhanced NF-κB activity was measurable from in vivo tumor xenografts by dual bioluminescence imaging. In contrast, paclitaxel and the platinum-taxol resistant cells showed down regulation in NF-κB activity. Intriguingly, silencing of MyD88 in cisplatin resistant and MyD88^positive TOV21G and SKOV3 cells showed enhanced NF-κB activity after cisplatin but not after paclitaxel or platinum-taxol treatments. Our data thus suggest that NF-κB signaling is important for maintenance of cisplatin resistance but not for taxol or platinum-taxol resistance in absence of an active TLR-4/MyD88 receptor mediated cell survival pathway in epithelial ovarian carcinoma.     

细胞凋亡抑制蛋白cIAP 与卵巢癌耐药性的研究进展

卵巢恶性肿瘤是女性生殖系统三大恶性肿瘤之一,其发病率在女性生殖系统肿瘤中占第三位,而死亡率却高居首位。目前对于晚期卵巢癌(Ⅲ或Ⅳ期)多倾向于用新辅助化疗+肿瘤细胞减灭术+术后周期性化疗的治疗方法。但是,尽管多数患者在最初对化疗药物较敏感,但仍有60%~80%最终死于卵巢癌,这些患者大部分都对化疗药物产生了耐药性,在更换新的化疗方案初期是有效的,但最终仍会耐药。近年来,有关细胞凋亡抑制蛋白(cIAP,cellular inhibitors of apoptosis proteins)在卵巢癌复发耐药中的作用机制的研究越来越受到重视。研究证实,cIAP在耐药肿瘤细胞中呈高表达,并与多种因子共同参与形成了上皮性卵巢癌的耐药机制,抑制了化疗药物引起的肿瘤细胞的凋亡。这些发现为攻克卵巢癌的耐药机制提供了重要线索,也为卵巢癌化疗药物的应用指出了新的方向。     

NF-κB targeting for overcoming tumor resistance and normal tissues toxicity

Radiotherapy and chemotherapy are two famous modalities in tumor-targeted therapy that lead to systemic and local toxicities for normal tissues. Moreover, several studies have confirmed that exposure of the tumor to radiation or chemotherapy drugs stimulate some signaling pathways in the tumor microenvironment (TME), leading to resistance of cancer cells to apoptosis, as well as promoting angiogenesis and tumor growth. Nuclear factor kappa B (NF-κB) plays a central role in the regulation of inflammatory responses in both normal tissues and tumors via the release of several cytokines, regulation of prostaglandins, reduction/oxidation (redox) reactions, angiogenesis, and cell death. Upregulation of NF-κB in normal tissues causes an appearance of inflammatory reactions and oxidative stress, whereas it regulates angiogenesis and suppresses apoptosis, leading to resistance to subsequent doses of radiation or chemotherapy. Selective inhibition of NF-κB in experimental studies has shown promising results for tumor sensitization via apoptosis induction, inhibition of angiogenesis, and increasing delay of tumor growth. The use of some agents for NF-κB inhibition has been shown to alleviate radiation/chemotherapy toxicities in normal cells/ tissues. In this current review, we explained the pivotal role of NF-κB in both normal tissue toxicity and tumor resistance. We also discussed the promising strategies for overcoming these problems with regard to chemotherapy and radiotherapy.     

Effects of antioxidants and nitric oxide on TNF-alpha-induced adhesion molecule expression and NF-kappaB activation in human dermal microvascular endothelial cells

Cell adhesion molecules expressed on endothelial cells in inflamed skin appear to be controlled by the actions of cytokines and reactive oxygen species. However, molecular mechanisms of the expression of adhesion molecules during skin inflammation are currently not well understood. To evaluate the role of antioxidants and nitric oxide in modulating inflammatory processes in the skin, we examined the effects of pyrrolidine dithiocarbamate (PDTC, 0.1 mM) and spermine NONOate (Sper-NO, 1 mM) on adhesion molecule expression and nuclear factor kappa B (NF-kappaB) activation induced by TNF-alpha (10 ng/ml) in cultured human dermal microvascular endothelial cells (HDMEC). Treatment of cells with TNF-alpha for 4 h significantly induced the surface expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1). Treatment with TNF-alpha for 8 h significantly induced the surface expression of E-selectin, ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1). The up-regulation of these adhesion molecules was suppressed significantly by pretreatment with PDTC or Sper-NO for 1 h. The mRNA expression of E-selectin, ICAM-1 and VCAM-1, and activation of NF-kappaB induced by TNF-alpha for 2 h were significantly decreased by the above two pretreatments. N-acetylcysteine (10 mM) and S-nitroso-N-acetylpenicillamine (1 mM) had no significant inhibitory effects on the cell surface and mRNA expression of these adhesion molecules stimulated by TNF-alpha. These findings indicate that both cell surface and mRNA expression of adhesion molecules in HDMEC induced by TNF-alpha are inhibited significantly by pretreatment with PDTC or Sper-NO, possibly in part through blocking the activation of NF-kappaB. These results suggest a potential therapeutic approach using antioxidant agents or nitric oxide pathway modulators in the treatment of inflammatory skin diseases.     

Lysophosphatidylcholine-induced apoptosis in H19-7 hippocampal progenitor cells is enhanced by the upregulation of Fas Ligand

Lysophospholipids regulate a wide array of biological processes including apoptosis and neutrophil migration. Fas/Apo-1 and its ligand (FasL) participate in neuronal cell apoptosis causing various neurological diseases. Here, we use hippocampal neuroprogenitor cells to investigate how lysophosphatidylcholine (LPC) induces apoptosis in H19-7 hippocampal progenitor cells via Fas/Fas ligand-mediated apoptotic signaling pathway. Exposed cells with LPC presented on apoptotic morphology, positive TUNEL staining, and DNA fragmentation. We found that the expression of FasL was increased after LPC treatment. Furthermore, LPC-induced H19-7 cell apoptosis was decreased by agonistic anti-FasL antibody. In addition to promotion of caspase cascade activity by LPC, the administration of the caspase inhibitor, DEVD-fmk, prevented H19-7 cell apoptosis. LPC also increased the activation of nuclear factor-κB (NF-κB), which in turn, significantly increased FasL mRNA level. The increase in FasL mRNA level by NF-κB transfection was significantly decreased in the presence of IκB-SR, a super-repressor of IκB. Taken together, these results demonstrate that LPC has the ability to induce apoptosis in H19-7 cells through the upregulation of FasL expression via NF-κB activation.