肝X受体激动剂对脂多糖诱导的炎症反应相关因子IRAK-4和NF-κB的影响

目的:观察在枯否细胞中人工合成的肝X受体激动剂在脂多糖(LPS)诱导的炎症反应中,对白细胞介素-1受体相关激酶-4(IRAK-4)和核因子NF-κB的影响.方法:雄性昆明小鼠,用胶原酶原位灌注法分离和培养肝脏Kupffer细胞,获得的细胞随机分为正常对照组、 LPS处理组、 LXR人工合成激动剂T0901317处理组和LPS+T0901317共同处理组.实时-聚合酶链式反应和蛋白Western blot检测各组细胞LXR、 IRAK-4和NF-κB的 mRNA和蛋白表达水平;凝胶电泳迁移率(EMSA)检测NF-κB活性水平.结果:LXR mRNA和蛋白在T0901317组表达都是最高的,而在LPS处理组最低.IRAK4和NF-κB的mRNA和蛋白水平在LPS处理组最高,联合处理组要低于LPS处理组.NF-κB的活性在LPS最高,联合处理组和T0901317处理组都较LPS组降低.结论:LXR激动剂能有效的上调LXR基因和蛋白水平,同时抑制TLR4信号通路中IRAK-4和NF-κB的mRNA水平和蛋白表达水平,并且能抑制NF-κB的活化.     

小檗碱对神经病理性疼痛大鼠疼痛行为及IRAK1/TRAF6信号通路介导的神经炎症的影响

目的：探讨小檗碱对神经病理性疼痛大鼠是否具有疼痛缓解作用,并分析白细胞介素1受体相关激酶（IRAK1）/肿瘤坏死因子受体相关因子6(TRAF6)通路在其中的作用机制。方法：60只SD大鼠随机分为假手术组、脊神经结扎组（模型组）、小檗碱（低、高剂量）组及阳性药物（阿魏酸钠）组,每组12只。对各组大鼠进行动物行为学评估,测定大鼠后足热缩足反射潜伏期（TWL）、机械缩足反射阈值（MWT）;六胺银染色观察患侧脊髓背角病理变化;ELISA法检测各组大鼠背根神经节中炎症相关因子肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)和IL-6的表达水平;RT-qPCR法和Western blot法分别检测脊髓IRAK1和TRAF6的mRNA及蛋白表达水平。结果：脊髓背角病理切片显示,模型组出现明显的神经元纤维增粗并缠绕成结,且有大量空泡变性,并且神经细胞的胞质出现含有嗜银颗粒的空泡;小檗碱和阳性药物治疗后脊髓背角损伤明显减少。与假手术组相比,模型组MWT和TWL显著降低,大鼠背根神经节中TNF-α、IL-1β和IL-6含量均显著升高,脊髓中IRAK1和TRAF6 mRNA和蛋白表达量显著升高（P...     

Toll样受体信号通路中MyD88的研究进展

MyD88是Toll样受体信号通路中的重要转导蛋白,其依赖的信号通路以及调控的基因产物在固有免疫和适应性免疫中均发挥着关键作用。本文对MyD88及其依赖的信号通路做一简要综述,以期为临床预防和治疗疾病提供新的思路和方法。     

SOCS1负性调节细胞因子和Toll样受体信号通路的研究进展

细胞因子(CK)信号通路和Toll样受体(TLRs)信号通路在调节免疫细胞增殖、分化和存活,以及维持免疫稳态过程中发挥重要作用.在细胞内,上述信号传导通路受多个负性调节分子的严格调控,其中细胞因子信号传导抑制蛋白1( SOCS1)是最重要的一个分子.SOCS1是一个JAK结合蛋白,可通过多靶点干预对CK和TLR信号通路...     

PPARs与TLR-NF-κB信号通路

过氧化物酶体增殖物激活受体(peroxisome proliferator-activated receptors,PPARs)属于核受体超家族,它们通过调控靶基因转录参与体内多种生理病理过程。近年来,随着药理学及临床医学对PPARs的深入研究,其潜在的抗炎效应引起了人们的广泛关注。据报道,激活PPARs是他汀类药物产生抑炎效应的实现途径之一。他汀类能够激活PPARγ并抑制LPS诱导的巨噬细胞的细胞因子表达 ^[1]。 Sugamura等^[2]的研究结论也支持该项发现,其数据显示他汀类通过激活PPARγ稳定动脉粥样硬化斑块,并且联合应用辛伐他汀与PPARγ激动剂,在抑制动脉粥样硬化斑块的治疗中显示出积极疗效。这一发现为PPARs干预多种慢性非细菌性致炎疾病如动脉粥样硬化、糖尿病等,提供了有力证据。而Toll样受体(Toll-like receptor,TLR)-核因子κB(nuclear factor,NF-κB)信号通路是人体炎症与免疫应答的主要组成部分。本文就PPARs与TLR-NF-κB信号通路在准炎症反应状态下及病理性炎症反应状态下的相互作用作一综述。     

白介素1信号转导研究进展

白介素 1(IL 1)是在局部和全身炎症反应中起核心作用的细胞因子 ,其信号转导机制极为复杂。最近几年发现了几条重要的信号转导途径。分别为 :IL 1受体相关激酶途径、磷脂酰肌醇 3 激酶信号转导途径、JAK STAT信号通路和离子通道。这些信号转导途径的发现为深入理解IL 1的信号转导机制提供了新的理论 ,并为炎症治疗开辟了新思路     

Toll样受体4信号通路在酒精性肝病发病机制中作用的研究进展

众所周知，肝脏是人体的重要解毒器官，长期过量饮酒对肝脏的损伤已经引起人们的重视。据统计，三分之一的酗酒者可以发展为脂肪肝、肝纤维化，严重的甚至可演变为肝硬变或肝癌。因而深入研究酒精性肝病的发病机制具有重要意义。本文从rrOll样受体4(Toll like receptor 4，TLR4)及其信号转导途径中的重要激酶白介素1受体相关激酶(Interleukin-1 Receptor—Associated Kinase,     

Novel Role and Regulation of the Interleukin-1 Receptor Associated Kinase （IRAK） Family Proteins

The interleukin-1 receptor associated kinases(IRAKs)sit at the bottle neck for the Toll-like-receptor(TLR)mediated signal transduetion process controlling host innate immune response.However,the exact role andregulation of IRAKs are still in the early stage and not fully understood.This review intends to summarize therecent advancement in this important topic and points out areas that need further intensive investigation.Cellular& Molecular Immunology.2005:2(1):36-39.     

负性调控因子IRAKM 在系统性红斑狼疮免疫调节异常中的作用

目的:研究白介素-1 受体相关激酶-M(IRAKM)在系统性红斑狼疮(SLE)中的表达及其与免疫调节的关系。方法:将103 例SLE 患者根据其疾病活动度评分(SLEDAI)分为活动期组(55 例)和稳定期组(48 例),另选40 名体检健康者作为对照组;采用实时荧光定量PCR(RT-PCR)法检测3 组外周血单核细胞中IRAKM mRNA 的表达量,酶联免疫吸附法(ELISA)检测血清中抗ds-DNA 抗体、抗Sm 抗体水平,免疫散射比浊法测定血清补体C3、C4 水平;应用单因素方差分析法分析3 组各观察指标的差异,Pearson 或Spearman 分析IRAKM 与SLE 自身抗体及补体的相关性。结果:活动期组和稳定期组SLE 患者的IRAKM mRNA 表达量均明显低于对照组(P<0.05),且活动期组比稳定期组更低,差异有统计学意义(P<0.05);与对照组比,活动期组和稳定期组血清抗ds-DNA 抗体和抗Sm 抗体水平均明显升高(P<0.05),补体C3、C4 的水平均明显降低(P<0.05),且活动期组血清自身抗体和补体水平变化较稳定期组更显著(P<0.05);SLE 患者的IRAKM mRNA 表达量与抗ds-DNA 抗体和抗Sm 抗体水平呈负相关(P<0.05),与补体C3、C4 水平呈正相关(P<0.05)。结论:IRAKM 负性调控参与SLE的免疫调节过程,其表达水平与SLE 病情活动程度密切相关。     

白介素-1受体相关激酶-2调控白介素-1诱导的NF-κB活化

目的研究白介素 1(IL 1)受体相关激酸 2(IRAK 2)在IL 1诱导NF κB活化中的作用。方法分别以逆转录PCR法和Western杂交法 ,检测lipofectin介导的反义I RAK 2寡核苷酸转染的人脐静脉内皮细胞中 ,IRAK 2mR NA和蛋白表达水平。用夹心ELISA法检测NF κB的活化。结果反义IRAK 2寡核苷酸可阻断IRAK 2mRNA的翻译 ,从而抑制IRAK 2蛋白的表达 ,抑制率达45% ;反义IRAK 2寡核苷酸抑制IL 1诱导的NF κB活化 ,具有剂量和时间依赖性 ,3μg与8h时的抑制效果最好。结论IRAK 2可调控IL 1诱导的NF κB活化。     

肿瘤中雌激素信号转导通路的研究进展

雌激素（estrogen,E₂）可通过特异性结合并激活其受体传递信号,广泛调控机体的各种功能,如生殖功能、骨骼及其它组织的分化和维持等。雌激素受体属于核受体超家族,有3个亚类即雌激素受体α（estrogenreceptorα,ERα）、ERβ和最近发现的G蛋白偶联受体——GPR（G protein-coupled receptor）30/GPER（G protein-coupled estrogen receptor）。典型的ER作     

mTOR信号通路与细胞凋亡

哺乳类动物雷帕霉素靶蛋白(mTOR)主要通过上游信号转导通路磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(PKB/Akt)/mTOR信号通路及下游信号通路mTOR/ eIF4E结合蛋白1(4EBP1)、mTOR/p70S6激酶(p70S6K)在细胞生长、增值与分化和在血管再生、蛋白合成与降解中发挥作用.细胞凋亡是细胞的一种程序性死亡,在机体发育、组织代谢中有着重要作用,而细胞凋亡的异常调节与许多疾病的发生和发展紧密相连.近年研究发现,mTOR信号通路在细胞凋亡过程中扮演了重要角色,并已被作为新的药物治疗靶点.     

IRAK-4 as the central TIR signaling mediator in innate immunity

Toll-like receptors (TLRs), which recognize pathogen-associated molecular patterns and members of the proinflammatory interleukin-1 receptor (IL-1R) family, share homologies in their cytoplasmic domains. Engagement of members of both of these families initiates a common intracellular signaling cascade, in which MyD88 and tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) are key adaptor proteins. Signaling between MyD88 and TRAF6 is mediated by members of the IL-1R-associated kinase (IRAK) family; however, the exact function of each IRAK protein remains controversial. IRAK-1 is required for the optimal transduction of IL-1R- and TLR-mediated signals, but IRAK-1 can be replaced by other IRAKs. Surprisingly, gene targeting studies show that the newest IRAK protein, IRAK-4, has an essential role in mediating signals initiated by IL-1R and TLR engagement. The kinase activity of IRAK-4 might be necessary to functionally modify IRAK-1 and perhaps other signal transducing substrates. Understanding the role of IRAK-4 in innate immunity will enable us to design novel strategies for therapeutic intervention in human infectious disease.     

Apolipoprotein E reduces food intake via PI3K/Akt signaling pathway in the hypothalamus

Apolipoprotein E (apoE) is a satiation factor. While central apoE administration reduces food intake, the specific intracellular signaling mechanisms activated by apoE remain largely unknown. Using primary cultured hypothalamic neurons, we demonstrated that apoE treatment (50 nM) elicited rapid activation of the phosphatidylinositol-3-kinase (PI3K)/Akt signaling cascade. Specifically, apoE induced the phosphorylation of Akt, peaking at 30 min, and the increased phosphorylation of Akt was significantly attenuated after pretreatment with LY294002 (50 μM), an inhibitor of the PI3K signaling pathway. To determine whether the activation of PI3K by apoE is required for the ability of apoE to reduce food intake, LY294002 (1 nmol) was infused into the 3rd-cerebral ventricle before injection of an anorectic dose of apoE. Consistent with our previous report, apoE (4 μg) exerted significant reduction of food intake in the 4-h fasted rats, compared with saline. Pretreatment with LY294002 significantly attenuated the potency of exogenous apoE to induce satiation, while the same dose of PI3K inhibitor by itself caused only a slight non-significant decrease of food intake. These results indicate that the activation of the PI3K/Akt pathway is necessary for the acute effects of apoE on food intake.     

Reviews and prospectives of signaling pathway analysis in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing disease with disappointing survival rate, and uneffective therapeutic progress has been made in the last few years, forcing the urgent need to improve research to this disease. The commonly accepted pathogenic hypothesis of IPF is the trigger from continuous alveolar epithelium microinjuries and in the following series events, many signaling pathways were reported to lead to abnormal tissue repair and lung structure derangement in IPF, such as TGF-β, wnt, VEGF and PI3K–Akt signaling pathways. Traditional research of IPF related signaling pathway always focus on the independent function of pathway and disease signals, but the crosstalks and interactions among them were rarely valued. In this review, we summarize the signaling pathways which were reported to play important roles in the pathologic changes of IPF and the synergistic effect among those pathways. Next we discuss the application of genomics research and bioinformatics tools on IPF related pathway analysis, and give a systems biology perspective by integrating multi-level disease related data. The novel prospective of pathway analysis could tease out the complex pathway interaction profiles of IPF, and is powerful to detect IPF related biomarkers for early diagnose and potential therapeutic targets.     

Silver nanoparticles activate endoplasmic reticulum stress signaling pathway in cell and mouse models: The role in toxicity evaluation

Silver nanoparticles (AgNPs) attract considerable public attention both for their antimicrobial properties and their potential adverse effects. In the present study, endoplasmic reticulum (ER) stress was used as a sensitive and early biomarker to evaluate the toxic potential of AgNPs in three different human cell lines in vitro and in vivo in mice. In 16HBE cells, the activation of ER stress signaling pathway was observed by upregulated expression including xbp-1s, chop/DDIT3, TRIB3, ADM2, BIP, Caspase-12, ASNS and HERP at either the mRNA and/or protein levels. However, these changes were not observed in HUVECs or HepG2 cells. Furthermore, mice experiments showed that different tissues had various sensitivities to AgNPs following intratracheal instillation exposure. The lung, liver and kidney showed significant ER stress responses, however, only the lung and kidney exhibited apoptosis by TUNEL assay. The artery and tracheal tissues had lower ER stress and apoptosis after exposure. The lowest observable effect concentrations (LOEC) were proposed based on evaluation of AgNP induced ER stress response in cell and mouse models. In summary, preliminary evaluation of AgNP toxicity by monitoring the ER stress signaling pathway provides new insights toward the understanding the biological impacts of AgNPs. The adverse effects of exposure to AgNPs may be avoided by rational use within the safe dose.     

Murine coronavirus-induced oligodendrocyte apoptosis is mediated through the activation of the Fas signaling pathway

We previously showed that infection of rat oligodendrocytes by ultraviolet light-inactivated mouse hepatitis virus (MHV) resulted in apoptosis, suggesting that the apoptosis is triggered during cell entry. To further characterize the earliest apoptotic signaling events, here we treated cells with an antibody specific to the MHV receptor prior to and during virus infection or with an antibody specific to MHV spike protein following virus binding. Both treatments blocked virus infection and apoptosis, indicating that virus-receptor binding is necessary but not sufficient for the apoptosis induction. Furthermore, virus infection significantly increased the formation of the "death-receptor complexes" consisting of Fas, Fas-associated death domain and procaspase-8, but did not induce the complexes involving the tumor necrosis factor receptor and its associated death domain, demonstrating the specific activation of the Fas signaling pathway. Moreover, virus infection did not alter the abundance of the individual proteins of the complexes, suggesting that the activation of the Fas signaling pathway was at the post-translational level. Treatment with a Fas/Fc chimera, which blocks Fas-Fas ligand-mediated apoptosis, inhibited the formation of the complexes and blocked the activation of caspase-8 and apoptosis in MHV-infected cells. It also inhibited the release of cytochrome c from mitochondria and the activation of caspase-9. These results demonstrate that oligodendrocyte apoptosis is triggered by MHV infection during cell entry through the activation of the Fas signaling pathway.     

IRAK4 in TLR/IL-1R signaling: possible clinical applications

A member of the IL-1 receptor (IL-1R)-associated kinase (IRAK) family, IRAK4, has been shown to play an essential role in Toll-like receptor (TLR)-mediated signaling. IRAK4 kinase-inactive knockin mice have been shown to be completely resistant to LPS- and CpG-induced shock, due to impaired TLR-mediated induction of pro-inflammatory cytokines and chemokines. A reduction of LPS-, R848- and IL-1-mediated mRNA stability contributes to the reduced cytokine and chemokine production in bone marrow (BM)-derived macrophages from IRAK4 kinase-inactive knockin mice: however, not all of the TLR/IL-1R signaling events are ablated in IRAK4 kinase-inactive knockin mice. A paper in this issue of the European Journal of Immunology shows that, while JNK activation is significantly impaired, NF-kappaB and IRF3 activation are retained in the absence of IRAK4 kinase activity. These residual TLR/IL-1R-induced signaling events allow the production of some cytokines and chemokines (including TNFalpha and CXCL1); at early times after the stimulation and induction of a group of TLR-mediated MyD88/IRAK4-independent genes in IRAK4 kinase-inactive knockin cells. Therefore, pharmacological blocking of IRAK4 kinase activity will retain some levels of host defence, while reducing the levels and duration of inflammatory responses, which should provide beneficial therapies for sepsis and chronic inflammatory diseases.     

ERK信号通路在檞皮素促大鼠MSCs成骨分化中的作用

目的:观察细胞外信号调节激酶(ERK)信号通路在檞皮素(QUE)促进SD大鼠骨髓间充质干细胞(MSCs)成骨分化过程中的作用。方法:(1)用0.01μmol/L、0.1μmol/L、1μmol/L、10μmol/L和100μmol/LQUE干预MSCs,MTT法检测各浓度QUE对MSCs增殖的影响,碱性磷酸酶(ALP)测定试剂盒检测各浓度QUE对MSCsALP表达的影响;(2)用ERK1/2抑制剂干预后,加入QUE,用ALP测定试剂盒检测ALP的表达,ELISA法检测Ⅰ型胶原(ColⅠ)和骨钙素(BGP)的表达,Westernblotting检测ERK1/2的表达,荧光定量PCR检测转化生长因子β₁(TGF-β₁)mRNA、骨形成蛋白2(BMP-2)mRNA和核心结合因子α1(Cbfα1)mRNA表达。结果:(1)0.1μmol/L、1μmol/L和10μmol/LQUE剂量依赖性地促进MSCsALP的表达,同时能促进MSCs的增殖;(2)与空白组相比,QUE组ALP、BGP和ColⅠ表达均增加(P<0.01),加入ERK1/2抑制剂后,磷酸化的ERK1/2表达减少(P<0.05),同时ALP、BGP和ColⅠ表达降低(P<0.01);(3)与空白组比较,QUE组TGF-β₁mRNA、BMP-2mRNA和Cbfα1mRNA的表达均增加(P<0.05),加入ERK1/2抑制剂后这3个基因的表达都下降(P<0.05)。结论:一定浓度的QUE能促进MSCs的增殖和成骨分化,ERK通路的激活在此过程中起到了重要的作用。     

不同信号通路基因在心脏和先天性心脏病发生和发展中的作用

先天性心脏病是一种常见的新生儿出生缺陷疾病,我国每年有12万～20万先心病患儿出生,其中多数为复杂型先天性心脏病,严重危害新生儿的健康,给社会和患者家庭带来沉重的负担。先天性心脏病的发病机制非常复杂,多数是由于环境因素和遗传因素共同作用的结果,其中许多患者是由于多种基因和信号通路共同作用的结果,例如, TGF-β、Nodal、MAPK、Wnt、Notch 等信号通路以及同型半胱氨酸甲硫氨酸循环途径与心脏发育密切相关,其中任何一个基因或信号通路异常都有可能导致先天性心脏病。该文以各种信号通路为主线,总结各信号通路及相关基因在心脏发育中的作用,以及这些信号通路和基因改变或异常表达引发先天性心脏病的致病机制。