阿托伐他汀对脂多糖诱导人脐静脉内皮细胞Toll样受体4及其下游信号转导通路的影响

背景:研究表明Toll样受体4参与了动脉粥样硬化的发生和发展,目前Toll样受体4与MyD88依赖性或MyD88非依赖性信号转导通路在动脉粥样硬化发生和发展中的机制尚不明确.目的:观察阿托伐他汀对脂多糖诱导的人脐静脉内皮细胞Toll样受体4及其下游信号转导通路主要元件MyD88、TRAF-6、TRAM及TRIF表达的影响,分析阿托伐他汀防治动脉粥样硬化的机制.方法:体外培养人脐静脉内皮细胞,用脂多糖刺激并加入阿托伐他汀干预24 h,收集细胞,用荧光定量PCR方法测定TLR4、MyD88、TRAF-6、TRAM及TRIF mRNA表达;用Western blotting法测定TLR4、MyD88及TRAF-6蛋白表达.结果与结论:用脂多糖刺激人脐静脉内皮细胞后,引起TLR4、MyD88、TRAF-6、TRAM和TRIF的高表达(P < 0.01),用阿托伐他汀干预后可显著抑制TLR4、MyD88及TRAF-6的表达(P < 0.01).提示阿托伐他汀可阻断Toll样受体4高表达,同时阻断Toll样受体4胞内信号转导的MyD88依赖性途径,这可能是阿托伐他汀抗动脉粥样硬化的作用机制之一.     

强直性脊柱炎髋关节病变中Toll样受体4表达的初步研究

目的 研究强直性脊柱炎（AS）髋关节病变中滑膜Toll样受体2和4（TLR2和TLR4）等受体的表达,以探讨髋关节病变的发病机制.方法 免疫组化染色法检测AS患者及对照组患者滑膜组织中TLR2、TLR4、髓样分化因子88（MyD88）、NFκB-p65表达情况.结果 AS组滑膜组织中TLR4、NFκB-p65表达阳性,TLR2、MyD88表达阴性,而对照组只NFκB-p65表达阳性,TLR2、TLR4、MyD88表达阴性.结论 AS患者髋关节病变存在TLR4高表达,并可能经MyD88非依赖性信号通路引起免疫炎症反应,导致髋关节破坏.     

Toll样受体4通路在幽门螺杆菌致病机制中的作用

比较Toll样受体4(TLR4)及MyD88在幽门螺杆菌(Hp)感染的BALB/c小鼠胃黏膜内表达含量随时间的变化,探讨TLR4通路在Hp致病机制中的作用.方法:70只BALB/c小鼠随机分为7组,分别于感染Hp的第0天、第3天、第7天、第14天、抗生素三联疗法治疗的第3天、第7天、第14天取得各组小鼠的胃黏膜标本,用RT-PCR和Western blotting的方法半定量检测TLR4、MyD88在基因和蛋白水平上的表达.结果:(1)小鼠TLR4、MyD88在感染Hp后均迅速升高,在治疗后迅速回落,但仍高于正常水平.(2)小鼠TLR4、MyD88的表达含量与病理严重程度无相关性.结论:TLR4信号通路参与了HP的致病机制,但与炎症反应的严重程度无相关性.     

过敏性紫癜患儿外周血单核细胞TLR2、TLR4、TLR6及与Treg相关细胞因子的表达

背景：Toll样受体介导的信号通路转导及调节性T细胞异常活化在过敏性紫癜发病中的作用不清楚。目的：研究Toll样受体TLR2、TLR4、TLR6在过敏性紫癜患儿外周血单核细胞的表达及调节性T细胞（Treg）的免疫应答,探讨TLR及Treg活化在敏性紫癜发病机制中的作用。方法：选择处于过敏性紫癜急性期的患儿42例为观察对象,另选取15名门诊健康查体儿童为正常对照组。采用流式细胞术检测外周血单核细胞的TLR2、TLR4、TLR6的蛋白表达量;应用反转录-聚合酶链反应（RT-PCR）及实时荧光定量PCR检测外周血单核细胞TLR信号途径分子MyD88 mRNA的基因相对表达量;ELISA法测Treg细胞分泌的转化生长因子β、白细胞介素10的血浆水平;两组间比较采用独立样本t或t’检验,相关性分析采用Pearson相关检验。结果与结论：过敏性紫癜患儿外周血单核细胞的TLR2、TLR4、TLR6蛋白的表达及MyD88 mRNA基因的相对表达量均显著高于对照组（P〈0.01）;过敏性紫癜患儿血浆中转化生长因子β、白细胞介素10均高于对照组（P〈0.05）;过敏性紫癜患儿TLR2、TLR4、TLR6的蛋白表达量与Myd88 mRNA的基因相对表达量呈正相关（P〈0.01）,与血浆白细胞介素10、转化生长因子β水平无明显相关（P〉0.05）。提示TLR2、TLR4、TLR6活化后可能通过MyD88依赖的途径参与敏性紫癜的发病,而过敏性紫癜急性期Treg代偿性活化可能为机体的保护性免疫应答。     

氟伐他汀对人THP-1细胞TLR4及下游信号转导通路的影响

目的探讨氟伐他汀对脂多糖(LPS)刺激的人急性单核细胞白血病细胞系(THP-1)Toll样受体4(TLR4)及下游信号转导通路的干预作用。方法采用不同剂量的氟伐他汀、LPS处理THP-1细胞,MTT法检测细胞增殖情况,实时荧光定量RTPCR(qRT-qPCR)检测细胞中TLR4和肿瘤坏死因子-α(TNF-α)mRNA的表达,western blot检测TLR4及下游磷酸化胞外信号调节激酶(ERK)、磷酸化核因子κB(NF-κB p65)蛋白的表达水平。ELISA法测定细胞培养上清中TNF-α蛋白的含量。结果氟伐他汀(10 mg/L)降低LPS刺激的THP-1细胞TLR4(蛋白质和mRNA)的表达(t分别为7.55、7.80,P均0.05),1、5、10mg/L氟伐他汀能显著抑制LPS刺激的下游分子ERK的磷酸化(q分别为11.78、18.15、18.88,P0.05);亦能抑制LPS刺激的NF-κB p65的磷酸化(q分别为5.13、6.87、11.68,P0.05)。同时,氟伐他汀(10 mg/L)能显著干预LPS刺激的细胞TNF-α(蛋白质和mRNA)的表达(q分别为4.23、3.01,P0.05)。结论氟伐他汀可通过干预LPS刺激的TLR4表达及下游分子ERK、NF-κB p65的磷酸化,抑制THP-1细胞TNF-α的表达,可能为氟伐他汀的抗炎机制之一。     

银杏叶提取物对脐静脉内皮细胞Toll样受体4/核因子-κB途径及细胞间黏附分子1表达的影响

目的：观察具有抗血小板活化因子、清除氧自由基、抗氧化作用的银杏叶提取物对脂多糖介导的人脐静脉内皮细胞Toll样受体4/核因子-κB信号途径及细胞间黏附分子、E-选择素表达的影响.方法：①实验于2003-01/2004-12在大连医科大学附属第二医院实验中心完成.取健康产妇分娩后的新鲜婴儿脐带（由本院分娩的产妇自愿提供）,应用胶原酶消化人脐静脉内皮,收集内皮细胞进行培养.②将培养成融合状态的内皮细胞随机分为4组：对照组：M199培养基中不加其他干预物质;脂多糖组：M199培养基中加入脂多糖1 mg/L;脂多糖＋银杏叶提取物50组：预先加入银杏叶提取物50（80 mg/L）,60 min后加入脂多糖1 mg/L;脂多糖＋咖啡酸苯乙酯组：预先加入咖啡酸苯乙酯（20 mg/L）30 min.于预12 h,收集细胞检测Toll样受体4和细胞间黏附分子1、E-选择素表达水平;干预1 h,收集细胞提取核蛋白检测转录核因子κB p65活化变化.③采用反转录聚合酶链反应检测Toll样受体4和细胞间黏附分子1、E-选择素mRNA表达水平;采用蛋白质印迹技术检测Toll样受体4蛋白表达水平及核因子-κB活化的变化;采用酶联免疫吸附方法检测人脐静脉内皮细胞表面细胞间黏附分子1,E-选择素蛋白表达.④多个样本均数的比较采用方差分析,多个样本均数的两两比较采用q检验结果：①人脐静脉内皮细胞Toll样受体4 mRNA和蛋白表达（A值）：脂多糖组明显高于对照组（P＜0.01）,脂多糖＋银杏叶提取物组和脂多糖＋咖啡酸苯乙酯组明显低于脂多糖组（P＜0.05～0.01）.②人脐静脉内皮细胞细胞间黏附分子1、E-选择素mRNA和蛋白表达（A值）：脂多糖组明显高于对照组（P＜0.01）,脂多糖＋银杏叶提取物组和脂多糖＋咖啡酸苯乙酯组明显低于脂多糖组（P＜0.05～0.01）.③人脐静脉内皮细胞核蛋白核因子-κB p65活化（A值）：脂多糖组明显高于对照组（P＜0.01）,脂多糖＋银杏叶提取物组和脂多糖＋咖啡酸苯乙酯组明显低于脂多糖组（P＜0.05）.结论：银杏叶提取物可能通过抑制核因子-κB活化,进而减弱Toll样受体4/核因子-κB途径从而抑制脂多糖介导的黏附分子表达及炎症反应.     

TLR4与MyD88蛋白在慢性肾功能不全组织中的表达研究

目的 通过研究Toll受体4(TLR4)及髓样细胞分化因子88(MyD88)在慢性肾功能不全组织中的表达,探讨TLR4/MyD88蛋白在慢性肾功能不全发生发展中的作用。方法 选取2011.07～2014.05华北理工大学附属医院确诊的40例肾功能不全的患者为观察对象,40例肾癌切除患者未被浸润的肾组织为对照,通过免疫组化方法检测慢性肾功能不全患者肾脏组织中TLR4及MyD88的表达情况,通过腺嘌呤(200mg/kg)连续灌胃制备大鼠模型,定时逆转录PCR(RT-PCR)及Western blot检测TLR4及MyD88的表达,同时将大鼠模型分为TLR4组、未阻断组和IgG对照组分别检测外周血中尿素氮(BNN)及肌酐(RE)的浓度。结果 慢性肾功能不全患者肾脏组织中TLR4及MyD88的表达明显高于正常对照组; 腺嘌呤制备的大鼠模型中的TLR4及MyD88的基因及蛋白的表达明显高于正常大鼠; TLR4阻断组尿素氮(15.65±3.97mmol/L)明显低于未阻断组(23.33±7.62mmol/L)及IgG对照组(26.33±6.77mmol/L)(t=2.887,P=0.045); 肌酐(523.89±52.67μmol/L)也明显低于未阻断组(789.51±98.17μmol/L)及IgG对照组(809.51±94.19μmol/L)(t=4.125,P=0.015)。结论 TLR4及MyD88蛋白在慢性肾功能不全中表达增加,并且显著促进疾病的发展过程。     

沉默Toll样受体4基因表达的RNAi慢病毒载体的构建

背景：Toll样受体4（toll-like receptor4,TLR4）是介导内毒素/脂多糖应答的主要受体,在由内毒素诱导的炎性反应的信号通路中发挥着重要作用。目的：构建人TLR4基因的RNA干扰慢病毒载体,并观察其对人脐静脉内皮细胞TLR4在蛋白水平的沉默效应。方法：利用Invitrogen在线软件设计人TLR4基因shRNA序列,合成、退火形成双链寡核苷酸后克隆到线性载体pENTRTM/H1/TO的黏性末端,并进行DNA测序。得到的阳性重组子再与慢病毒载体进行重组反应,从而获得干扰TLR4基因真核表达的慢病毒载体。在脂质体的介导下将慢病毒包装辅助复合体和TLR4基因的真核表达慢病毒载体导入293FT细胞包装病毒,测定病毒滴度,感染人脐静脉内皮细胞,检验其干扰TLR4基因表达的有效性。结果与结论：实验成功构建TLR4基因真核表达慢病毒干扰载体并获得相应的慢病毒,病毒滴度为8.7×106U/mL。免疫印迹杂交结果表明,所获得的慢病毒感染人脐静脉内皮细胞TLR4基因在蛋白水平的表达显著降低。实验成功构建了人TLR4基因慢病毒RNA干扰表达载体,并验证了其在人脐静脉内皮细胞上的有效性。     

银杏叶提取物对脐静脉内皮细胞Toll样受体4／核因子-кB途径及细胞间黏附分子1表达的影响

目的：观察具有抗血小板活化因子、清除氧自由基、抗氧化作用的银杏叶提取物对脂多糖介导的人脐静脉内皮细胞Toll样受体4／核因子-κB信号途径及细胞间黏附分子、E-选择素表达的影响。 方法：①实验于2003-01／2004-12在大连医科大学附属第二医院实验中心完成。取健康产妇分娩后的新鲜婴儿脐带(由本院分娩的产妇自愿提供)，应用胶原酶消化人脐静脉内皮，收集内皮细胞进行培养。②将培养成融合状态的内皮细胞随机分为4组：对照组：M199培养基中不加其他干预物质；脂多糖组：M199培养基中加入脂多糖1mg／L；脂多糖+银杏叶提取物50组：预先加入银杏叶提取物50(80mg／L)，60min后加入脂多糖1mg／L；脂多糖+咖啡酸苯乙酯组：预先加入咖啡酸苯乙酯(20mg／L)30min。干预12h，收集细胞检测Toll样受体4和细胞间黏附分子1、E-选择素表达水平；干预1h，收集细胞提取核蛋白检测转录核因子κBp65活化变化。③采用反转录聚合酶链反应检测Toll样受体4和细胞间黏附分子1、E-选择素mRNA表达水平；采用蛋白质印迹技术检测Toll样受体4蛋白表达水平及核因子-KB活化的变化；采用酶联免疫吸附方法检测人脐静脉内皮细胞表面细胞间黏附分子1，E-选择素蛋白表达。④多个样本均数的比较采用方差分析，多个样本均数的两两比较采用q检验 结果：①人脐静脉内皮细胞Toll样受体4mRNA和蛋白表达(A值)：脂多糖组明显高于对照组(P<0．01)，脂多糖+银杏叶提取物组和脂多糖+咖啡酸苯乙酯组明显低于脂多糖组(p<0．05～0．01)。②人脐静脉内皮细胞细胞间黏附分子1、E-选择素mRNA和蛋白表达(A值)：脂多糖组明显高于对照组(P<0．01)，脂多糖+银杏叶提取物组和脂多糖+咖啡酸苯乙酯组明显低于脂多糖组(P<0．05～0．01)。③人脐静脉内皮细胞核蛋白核因子-κBp65活化(A值)：脂多糖组明显高于对照组(P<0．01)，脂多糖+银杏叶提取物组和脂多糖+咖啡酸苯乙酯组明显低于脂多糖组(P<0．05)。 结论：银杏叶提取物可能通过抑制核因子-κB活化，进而减弱Toll样受体4／核因子-κB途径从而抑制脂多糖介导的黏附分子表达及炎症反应。     

Toll样受体4信号转导通路在脑梗死后运动康复中的研究前景

近年来发现,Toll样受体4(TLR4)信号转导通路在脑梗死后的炎症损伤中起重要作用,运动训练能降低TLR4的表达,减轻炎性损伤。我们可以考虑从TLR4信号转导方向深入探讨脑梗死后运动康复的作用机制。     

LPS-TLR4 signaling to IRF-3/7 and NF-kappaB involves the toll adapters TRAM and TRIF

Toll-IL-1-resistance (TIR) domain-containing adaptor-inducing IFN-beta (TRIF)-related adaptor molecule (TRAM) is the fourth TIR domain-containing adaptor protein to be described that participates in Toll receptor signaling. Like TRIF, TRAM activates interferon regulatory factor (IRF)-3, IRF-7, and NF-kappaB-dependent signaling pathways. Toll-like receptor (TLR)3 and 4 activate these pathways to induce IFN-alpha/beta, regulated on activation, normal T cell expressed and secreted (RANTES), and gamma interferon-inducible protein 10 (IP-10) expression independently of the adaptor protein myeloid differentiation factor 88 (MyD88). Dominant negative and siRNA studies performed here demonstrate that TRIF functions downstream of both the TLR3 (dsRNA) and TLR4 (LPS) signaling pathways, whereas the function of TRAM is restricted to the TLR4 pathway. TRAM interacts with TRIF, MyD88 adaptor-like protein (Mal)/TIRAP, and TLR4 but not with TLR3. These studies suggest that TRIF and TRAM both function in LPS-TLR4 signaling to regulate the MyD88-independent pathway during the innate immune response to LPS.     

TIR domain--containing adaptors regulate TLR-mediated signaling pathways

Recognition of pathogens by Toll-like receptors (TLRs) triggers innate immune responses via signaling pathways mediated by several Toll/IL-1R (TIR) domain-containing adaptors such as MyD88, TIRAP, and TRIF. MyD88 is a common adaptor that is essential for proinflammatory cytokine production, whereas TRIF mediates the MyD88-independent pathway from TLR3 and TLR4 that is responsible for type I interferon production in response to double-stranded RNA and LPS, respectively. TIRAP specifically participates in the MyD88-dependent pathways shared by TLR2 and TLR4, and TRAM is essential for the TLR4-mediated MyD88-independent pathway. Thus, TIR domain-containing adaptors play an important role in the TLR mediated signaling pathways.     

Signaling Flux Redistribution at Toll-Like Receptor Pathway Junctions

Various receptors on cell surface recognize specific extracellular molecules and trigger signal transduction altering gene expression in the nucleus. Gain or loss-of-function mutations of one molecule have shown to affect alternative signaling pathways with a poorly understood mechanism. In Toll-like receptor (TLR) 4 signaling, which branches into MyD88- and TRAM-dependent pathways upon lipopolysaccharide (LPS) stimulation, we investigated the gain or loss-of-function mutations of MyD88. We predict, using a computational model built on the perturbation-response approach and the law of mass conservation, that removal and addition of MyD88 in TLR4 activation, enhances and impairs, respectively, the alternative TRAM-dependent pathway through signaling flux redistribution (SFR) at pathway branches. To verify SFR, we treated MyD88-deficient macrophages with LPS and observed enhancement of TRAM-dependent pathway based on increased IRF3 phosphorylation and induction of Cxcl10 and Ifit2. Furthermore, increasing the amount of MyD88 in cultured cells showed decreased TRAM binding to TLR4. Investigating another TLR4 pathway junction, from TRIF to TRAF6, RIP1 and TBK1, the removal of MyD88-dependent TRAF6 increased expression of TRAM-dependent Cxcl10 and Ifit2. Thus, we demonstrate that SFR is a novel mechanism for enhanced activation of alternative pathways when molecules at pathway junctions are removed. Our data suggest that SFR may enlighten hitherto unexplainable intracellular signaling alterations in genetic diseases where gain or loss-of-function mutations are observed.     

MyD88 but not TRIF is essential for osteoclastogenesis induced by lipopolysaccharide, diacyl lipopeptide, and IL-1alpha

Myeloid differentiation factor 88 (MyD88) plays essential roles in the signaling of the Toll/interleukin (IL)-1 receptor family. Toll-IL-1 receptor domain-containing adaptor inducing interferon-beta (TRIF)-mediated signals are involved in lipopolysaccharide (LPS)-induced MyD88-independent pathways. Using MyD88-deficient (MyD88-/-) mice and TRIF-deficient (TRIF-/-) mice, we examined roles of MyD88 and TRIF in osteoclast differentiation and function. LPS, diacyl lipopeptide, and IL-1alpha stimulated osteoclastogenesis in cocultures of osteoblasts and hemopoietic cells obtained from TRIF-/- mice, but not MyD88-/- mice. These factors stimulated receptor activator of nuclear factor-kappaB ligand mRNA expression in TRIF-/- osteoblasts, but not MyD88-/- osteoblasts. LPS stimulated IL-6 production in TRIF-/- osteoblasts, but not TRIF-/- macrophages. LPS and IL-1alpha enhanced the survival of TRIF-/- osteoclasts, but not MyD88-/- osteoclasts. Diacyl lipopeptide did not support the survival of osteoclasts because of the lack of Toll-like receptor (TLR)6 in osteoclasts. Macrophages expressed both TRIF and TRIF-related adaptor molecule (TRAM) mRNA, whereas osteoblasts and osteoclasts expressed only TRIF mRNA. Bone histomorphometry showed that MyD88-/- mice exhibited osteopenia with reduced bone resorption and formation. These results suggest that the MyD88-mediated signal is essential for the osteoclastogenesis and function induced by IL-1 and TLR ligands, and that MyD88 is physiologically involved in bone turnover.     

Selective modulation of TLR4-activated inflammatory responses by altered iron homeostasis in mice

Mice deficient in the hemochromatosis gene, Hfe, have attenuated inflammatory responses to Salmonella infection associated with decreased macrophage TNF-α and IL-6 biosynthesis after exposure to LPS. In this study, we show that the abnormal cytokine production is related to impaired TLR4 signaling. Despite their abnormal response to LPS, Hfe KO macrophages produced amounts of TNF-α similar to those in WT cells after TLR2 stimulation. Consistent with this finding, LPS-induced activation of Mal/MyD88-dependent events was normal in the mutant macrophages. However, LPS-induced IFN-β expression, a TRAM/TRIF-dependent response activated by TLR4, was reduced by Hfe deficiency. This reduction could be replicated in WT macrophages with the use of iron chelators. In contrast, TLR3-activated expression of IFN-β, a TRIF-dependent response, was normal in Hfe KO macrophages and was unaffected by iron chelation. Our data suggest that low intracellular iron selectively impairs signaling via the TLR4/TRAM/TRIF pathway proximal to TRIF and results in reduced LPS-induced cytokine expression. Furthermore, by mimicking the altered iron metabolism associated with Hfe deficiency, we found that 3 different inhibitors of hepcidin attenuated Salmonella-induced and noninfectious enterocolitis. Thus, manipulation of iron homeostasis could represent a new therapeutic approach to controlling inflammation.     

MyD88-dependent IL-1 receptor signaling is essential for gouty inflammation stimulated by monosodium urate crystals

While it is known that monosodium urate (MSU) crystals cause the disease gout, the mechanism by which these crystals stimulate this inflammatory condition has not been clear. Here we find that the Toll/IL-1R (TIR) signal transduction adaptor myeloid differentiation primary response protein 88 (MyD88) is required for acute gouty inflammation. In contrast, other TIR adaptor molecules, TIRAP/Mal, TRIF, and TRAM, are not required for this process. The MyD88-dependent TLR1, -2, -4, -6, -7, -9, and -11 and IL-18 receptor (IL-18R) are not essential for MSU-induced inflammation. Moreover, MSU does not stimulate HEK cells expressing TLR1-11 to activate NF-kappaB. In contrast, mice deficient in the MyD88-dependent IL-1R showed reduced inflammatory responses, similar to those observed in MyD88-deficient mice. Similarly, mice treated with IL-1 neutralizing antibodies also showed reduced MSU-induced inflammation, demonstrating that IL-1 production and IL-1R activation play essential roles in MSU-triggered inflammation. IL-1R deficiency in bone marrow-derived cells did not affect the inflammatory response; however, it was required in non-bone marrow-derived cells. These results indicate that IL-1 is essential for the MSU-induced inflammatory response and that the requirement of MyD88 in this process is primarily through its function as an adaptor molecule in the IL-1R signaling pathway.     

大黄牡丹汤含药血清对脂多糖刺激的小鼠巨噬细胞RAW 264.7中TRIF和TRAM表达的影响

目的:研究大黄牡丹汤含药血清对细菌脂多糖(lipopolysaccharide,LPS)刺激的小鼠巨噬细胞株RAW264.7中Toll白介素受体相关调节因子(Toll-interleukin 1 receptor-domain-containing adapter-inducing interferon-b,TRIF)及TRIF相关的接头分子(TRIF-related adaptor molecule,TRAM)表达的影响。方法:20只SD大鼠随机分为4组:对照组以及中药高、中、低浓度组,每组5只。各组大鼠分别相应地以0.9%氯化钠液或高、中、低浓度大黄牡丹汤(13.2、6.6、3.3 g/kg)连续灌胃7 d,末次灌胃给药2 h后行心脏采血并处死,分离血清(即含药血清)。体外培养RAW264.7细胞,随机分为对照组、模型组(LPS处理组)以及中药高、中、低浓度组。除对照组外,其他组均用5μg/mL LPS刺激RAW264.7细胞24 h,3个中药组同时给予相应浓度大黄牡丹汤含药血清进行干预,分别采用RT-PCR和Western blotting法检测各组细胞中TRIF和TRAM的mRNA和蛋白的表达水平。结果:模型组细胞TRIF和TRAM的mRNA和蛋白表达水平均显著高于对照组(P0.01),中药中、高浓度组细胞TRIF和TRAM的mRNA表达水平均显著低于中药低浓度组及模型组(P0.01),中药中、高浓度组TRIF和TRAM的蛋白表达水平也明显低于低浓度组(P0.05)及模型组(P0.01)。结论:大黄牡丹汤含药血清可抑制LPS刺激后RAW264.7细胞中TRIF和TRAM的表达。     

MyD88 inhibition amplifies dendritic cell capacity to promote pancreatic carcinogenesis via Th2 cells

The transition of chronic pancreatic fibroinflammatory disease to neoplasia is a primary example of the paradigm linking inflammation to carcinogenesis. However, the cellular and molecular mediators bridging these entities are not well understood. Because TLR4 ligation can exacerbate pancreatic inflammation, we postulated that TLR4 activation drives pancreatic carcinogenesis. In this study, we show that lipopolysaccharide accelerates pancreatic tumorigenesis, whereas TLR4 inhibition is protective. Furthermore, blockade of the MyD88-independent TRIF pathway is protective against pancreatic cancer, whereas blockade of the MyD88-dependent pathway surprisingly exacerbates pancreatic inflammation and malignant progression. The protumorigenic and fibroinflammatory effects of MyD88 inhibition are mediated by dendritic cells (DCs), which induce pancreatic antigen-restricted Th2-deviated CD4(+) T cells and promote the transition from pancreatitis to carcinoma. Our data implicate a primary role for DCs in pancreatic carcinogenesis and illustrate divergent pathways in which blockade of TLR4 signaling via TRIF is protective against pancreatic cancer and, conversely, MyD88 inhibition exacerbates pancreatic inflammation and neoplastic transformation by augmenting the DC-Th2 axis.