黄芪多糖通过NF-κB诱导巨噬细胞产生NO和TNF-α

Objective To explore the molecular and cell signal transduction mechanism of Astragalus mongholicus polysaccharides (ASP) on macrophage. Methods After stimulating RAW264.7, the change in value of NF-κB was determined by Western blot. The induction of NO and secretion of TNF-α by ASP in macrophage was observed with or without inhibitor of NF-κB using Griess method. Moreover, protein levels of TNF-α secreted by macrophage were investigated with ELISA in respond to ASP. Results 4 h after stimulation by 100 μg/ml ASP, the concentration of NF-κB in nucleus increased significantly, peaked at 6 h. 16 h after stimulation by 100 μg/ml ASP, the activity of iNOS[(23.54±2.41) U/mg protein; P<0.01], producton of NO [(18.9±1.5)μmol/L, P<0.01] and level of TNF-α[(81.2±16.7)pg/ml, P<0.0l] in macrophage were improved markedly. Blocking NF-κB with inhibitor results in decreased levels of NO and TNF-α. Conclusion The results suggest that NF-κB play an important role in induction of NO and TNF-α by ASP in macrophage.     

黄芪多糖通过NF-κB诱导巨噬细胞产生NO和TNF-α

目的 通过体外试验研究黄芪多糖(Astragalus mongholicus polysaccharides,ASP)激活巨噬细胞产生NO和TNF-α的分子机制和细胞内信号转导机制.方法 黄芪多糖刺激RAW264.7细胞,用Western blot方法 检测细胞核内核转录因子-κB(NF-κB)的变化.用Griess还原法观察黄芪多糖对巨噬细胞释放NO的作用的影响以及NF-κB抑制剂对黄芪多糖诱导巨噬细胞释放NO作用和分泌TNF-α的影响.ELISA法检测黄芪多糖对巨噬细胞分泌肿瘤坏死因子-α(TNF-α)的变化.结果 100μg/ml黄芪多糖刺激RAW264.7细胞,4 h后可引起细胞核内NF-κB含量显著增加,6 h达到顶峰.16 h后可显著诱导NO[(18.9±1.5)μmol/L;P<0.01]释放和TNF-α分泌[(81.2±16.7)pg/ml,P<0.01]的增加,以及诱导型一氧化氮合酶(iNOS)[(23.54±2.41)U/mg蛋白质,P<0.01]活性的增加.NF-κB抑制剂吡咯烷二硫代氨基甲酸盐(PDTC)可明显抑制黄芪多糖诱导RAW264.7生成NO和分泌TNF-α.结论 NF-κB在黄芪多糖诱导巨噬细胞生成NO和TNF-α过程中发挥重要作用.     

LPS致大鼠肺泡巨噬细胞NF-κB促进TNF-α分泌

目的: 观察脂多糖（LPS）致大鼠肺泡巨噬细胞（AMs）中核因子NF-κB活性及其调控肿瘤坏死因子-α（TNF-α）分泌的作用。 方法: LPS作用大鼠AMs后，用电泳迁移率改变分析法（EMSA）测NF-κB活性；用特异的反义寡核苷酸阻断NF-κB亚基（p65）后，Western blotting检测p65表达变化；ELISA法检测细胞上清中TNF-α的含量。 结果: 于LPS作用AMs后4 h，NF-κB活性达到峰值，24 h仍维持在高水平；作用后4 h上清中TNF-α的含量达到峰值。反义寡核苷酸阻断NF-κB亚基（p65）表达后，LPS致AMs上清中TNF-α的含量显著低于未阻断组（P<0.01）。结论: LPS致大鼠AMs中NF-κB正向调控TNF-α分泌。     

NF-κB在急性胰腺炎中的研究进展

NF-κB(转录因子核因子-κB)是一类主要参与机体炎性分子表达调控的转录分子，在急性胰腺炎中，其表达也受到很大的影响，苓主要对近几年NF-κB在急性胰腺炎中的研究作一综述。     

PRDM1调控NF-κB信号通路对巨噬细胞极化和功能的影响

目的:本文旨在探讨正性调节区锌指蛋白1(PRDM1)对小鼠骨髓来源巨噬细胞(BMDMs)极化和功能的影响及其分子机制.方法:体外提取BMDMs作为研究对象,并进行极化诱导,采用荧光定量PCR和Western blot法检测不同极化状态的巨噬细胞PRDM1的表达水平;设计构建PRDM1过表达腺病毒载体,瞬时感染BMDMs...     

多黏菌素B对内毒素诱导的肺泡巨噬细胞中NF-κB活化的影响

目的 :观察多黏菌素B(PMB)对内毒素 (LPS)刺激大鼠肺泡巨噬细胞 (PAM)中核因子 κB(NF κB)激活通路的影响 ,并探讨PMB可能的抗炎效应。方法 :分离、培养大鼠PAM ,分为正常对照组、LPS刺激组及PMB +LPS干预组。各组PAM在刺激后 0、15、30、6 0、12 0和 2 4 0min分别固定 ,提取PAM核蛋白并收集细胞培养上清 ,采用原位杂交 (ISN)技术、凝胶电泳迁移率改变 (EMSA)及ELISA法 ,观察PAM中IKK βmRNA及IκB α的表达 ,检测PMB核蛋白提取物中NF κB的活性和上清液中TNF α的含量。结果 :LPS刺激组IKK βmRNA的水平 ,显著高于刺激前和正常对照组 (P <0 .0 1) ;IκB α的水平的变化趋势与IKK βmRNA刚好相反。NF κB活性的峰值相对于刺激前和正常对照组有显著升高 (P <0 .0 1)。培养上清中TNF α的含量 ,亦显著高于刺激前和正常对照组(P <0 .0 1)。PMB干预组NF κB的活性与TNF α的含量虽较刺激前和正常对照组升高 ,但均显著低于LPS刺激组 (P <0 .0 1)。IκB α水平的最低值显著高于LPS刺激组 (P <0 .0 1) ;而IKK βmRNA的峰值则显著低于LPS刺激组 (P <0 .0 1)。结论 :LPS能诱导PAM中的IKK β激活、IκB α降解和NF κB活化 ,并促进TNF α释放。PMB则能抑制LPS诱导的IKK β激活、IκB α降解、NF κB活化和TNF α     

NF-κB"decoy"寡核苷酸对LPS诱导巨噬细胞TNF-α和IL-6表达的影响

目的 :研究NF -κB“decoy”寡核苷酸 (ODNs)对LPS诱导小鼠巨噬细胞株J774 1细胞的TNF -α和IL - 6表达的影响 ,探讨F -κB“decoy”寡核苷酸防治LPS诱导急性炎性损伤的可行性。方法 :巨噬细胞株J774 1细胞接种于 6孔板中 ,4× 10 5个细胞/孔 ,37℃、5 %CO2 培养过夜 ,待细胞汇合至 80 % ,用无血清、无抗生素 16 4 0培养液洗涤细胞两次后随机分为 4组。内毒素刺激组 :用含 1mg/LLPS的培养液刺激 ,不加治疗 ;NODN治疗组 :用含 1mg/LLPS的培养液刺激 3h ,然后用脂质体介导 1μmol/L(终浓度 )NF -κB“decoy”ODNs治疗 ;SO…     

大鼠硅肺纤维化中NF-κB和MMP-9的表达

目的 研究核转录因子-κB(NF-κB)和基质金属蛋白酶-9(MMP-9)的表达在硅肺纤维化发生发展中的作用。方法 应用免疫组化SP法观察NF-κB和MMP-9在大鼠硅肺组织中的表达。结果 对照组支气管上皮细胞、肺巨噬细胞和肺间质细胞均可表达NF-κB和MMP-9，肺泡上皮细胞和血管内皮细胞未见表达。实验组的支气管上皮细胞、肺巨噬细胞、间质细胞和肺泡上皮细胞NF-κB、MMP-9表达均明显增加。在实验的每一个时间点，肺巨噬细胞、肺间质细胞中NF-κB和MMP-9的半定量表达基本同步，呈明显正相关。支气管上皮细胞NF-κB在1～28d均呈持续高水平表达，但MMP-9在14d后开始减少；肺泡上皮细胞NF-κB在114d呈较高水平表达，以后下降，而MMP-9仅于第3～7天时有阳性表达。结论 矽尘作用下肺内多种细胞NF-κB和MMP-9表达增加，并可能通过NF-κB介导调控MMP-9表达而影响硅肺的发生发展。     

NF-κB与危重病治疗

核因子 κB (NF κB)为一种参与多种炎症介质基因表达的转录因子。NF κB过度及长时间激活与许多炎性疾病 ,包括脓毒性休克、急性呼吸窘迫综合征 (ARDS)、缺血及再灌注损伤等有关。为减轻组织和器官损伤 ,NF κB在调控炎症中的重要作用使之成为一个治疗目标。通过基因治疗策略或药物抑制导致NF κB活化中的关键步骤 ,能调控NF κB信号转导。     

黄芪多糖对树突状细胞表型及功能成熟的影响

目的 通过体外试验研究黄芪多糖（Astragalus mongholicus, ASP） 对树突状细胞（dendritic cells，DC）功能调节的机制，为进一步阐明黄芪多糖的免疫学活性提供依据。方法 应用流式细胞仪检测技术、扫描电镜技术、酶联免疫吸附试验检测DC表型和功能的各种指标。结果 本实验应用小鼠骨髓来源的DC，通过体外试验证明了黄芪多糖能够提高DC表面分子CD11c和MHCⅡ的表达，并且呈黄芪多糖浓度依赖性；空白组DC的吞噬功能很强，LPS组DC和黄芪多糖处理组DC吞噬功能都明显下降；黄芪多糖能够促进DC白细胞介素-12（IL-12）的表达；电镜观察DC的超微结构，可见黄芪多糖处理组DC突起增多，形态上更加成熟。结论 本实验结果证实了黄芪多糖能促进小鼠骨髓来源的DC表型及功能的成熟。     

黄芪和何首乌对老龄小鼠脾保护作用的定量研究

本实验在建立环磷酰胺免疫抑制老龄小鼠模型基础上,定量比较了黄芪、何首乌单用和联用对脾和脾巨噬细胞的影响.结果黄芪、何首乌和黄芪加何首乌三组脾巨噬细胞的面数密度、面密度、吞噬率和吞噬指数均明显高于环磷酰胺组而灰度明显低于环磷酰胺组.与对照组相比,黄芪、何首乌和黄芪加何首乌三组的面数密度、面密度和吞噬指数均无明显差异而灰度皆增高;吞噬率在黄芪和何首乌组不如对照组而黄芪加何首乌组则达到对照组水平.表明黄芪和何首乌对环磷酰胺引起的脾抑制性改变有明显保护作用,两药联用效果更佳.     

Quercetin inhibits LPS-induced nitric oxide and tumor necrosis factor-alpha production in murine macrophages.

High amounts of nitric oxide and TNF-alpha generated by activated macrophages induce several pathophysiological conditions during acute and chronic inflammation. Identification of new pharmacological reagents that can prevent TNF-alpha and/or NO overproduction is of considerable medical interest. In this report we provide evidence that the overproduction of TNF-alpha and NO by LPS stimulated macrophages can be markedly inhibited by quercetin, a major active component of plant Rhododendron cinnabarium.     

Alcohol extracts of Echinacea inhibit production of nitric oxide and tumor necrosis factor-alpha by macrophages in vitro

It has been suggested that Echinacea has anti-inflammatory activity in vivo. Nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-1beta are important mediators in the inflammatory response. The effect of alcohol extracts of E. angustifolia (EA), E. pallida (EPA) and E. purpurea (EP) on the production of these inflammatory mediators in both LPS-stimulated RAW 264.7 macrophages in vitro and murine peritoneal exudate cells (PECs) in vivo were investigated. As macrophages produce these inflammatory mediators in response to pathogenic infection, parallel cultures of macrophages were studied for phagocytosis and intracellular killing of Salmonella enterica. EPA and EP in vitro inhibited NO production and TNF-α release in a dose-dependent manner. RAW 264.7 cells treated with EA or EP showed decreased killing over 24 h, although EA enhanced bacterial phagocytosis. Upon bacterial infection, RAW 264.7 cells produce high levels of NO; however, an Echinacea-mediated decrease in NO production was observed. Echinacea alcohol extracts administered orally at 130 mg/kg per day for seven days had a weak effect on NO production and phagocytosis by LPS-stimulated PECs. The results indicated that all Echinacea species significantly decreased inflammatory mediators in vitro, however, only EA and EP reduced bacterial killing. Oral administration of Echinacea alcohol extracts did not adversely affect the development and anti-bacterial function of inflammatory PECs in vivo, however, NO production was decreased during bacterial infection of PECs.     

Heat shock and 5-azacytidine inhibit nitric oxide synthesis and tumor necrosis factor-alpha secretion in activated macrophages

To elucidate the role of stress response during macrophage activation, the effects of heat shock and the amino acid analog, 5-azacytidine on nitric oxide (NO) production, tumor necrosis factor-alpha (TNF-alpha) secretion, and heat shock protein (HSP) synthesis have been studied in murine peritoneal macrophages (C57BL/6). Heat shock (1 hr at 43 degrees C) or 5-azacytidine markedly inhibited the release of NO into the medium from interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS)-stimulated macrophages. Although heat shock significantly decreased TNF-alpha secretion only at the initiation stage of macrophage stimulation, 5-azacytidine treatment resulted in a more prolonged reduction in the secretion of TNF-alpha. When heat-shocked cells were stimulated with IFN-gamma plus LPS under normal culture conditions at 37 degrees C, the heat shock-induced inhibition of NO release reversed progressively with increasing recovery time. Although the total amount of cellular HSP72 measured by Western blot increased time-dependently over 7 hr, newly synthesized HSP72 measured by [35S]methionine incorporation was evident only after 1 and 3 hr of recovery time after heat shock treatment. At these time points, the lowest nitrite accumulation and TNF-alpha secretion into the medium was evident. It is concluded that signaling pathways related to newly synthesized HSP such as HSP72 are implicated in the down regulation of NO synthesis and TNF-alpha secretion in macrophages.     

黄芪诱导大鼠骨髓间充质干细胞分化为神经样细胞的研究

目的研究大鼠骨髓间充质干细胞(MSCs)体外分离和培养方法,并用黄芪体外诱导骨髓间充质干细胞分化为神经细胞样细胞。方法利用梯度离心从大鼠骨髓中分离单核细胞进行培养,去除不贴壁的细胞,分离纯化,对其生长特性进行分析。采用含黄芪的无血清L-DMEM诱导分化为神经细胞样细胞,观察细胞形态变化,用免疫组织化学方法检测分化细胞中巢蛋白(nestin)、神经元特异性烯醇化酶(NSE)、胶质纤维酸性蛋白(GFAP)的表达。结果用含10%胎牛血清(FCS)的培养基培养,原代细胞贴壁生长,细胞形态均一,为纺锤形,有克隆团形成。传代培养时,形态变为成纤维细胞样,有较强的增殖能力。经黄芪诱导后,骨髓间充质干细胞形态发生改变,nestin、NSE和GFAP阳性,分化为神经元或胶质细胞样细胞。结论骨髓间充质干细胞可以体外分离、培养,在一定条件下向神经样细胞分化。     

Silica-induced apoptosis in murine macrophage: involvement of tumor necrosis factor-alpha and nuclear factor-kappaB activation

Although it is clearly established that surfactant protein A (SP-A) is secreted by type II pneumocytes as a component of pulmonary surfactant, its secretion pathway as well as its subcellular localization in the human lung are uncertain. We therefore studied the intracellular and intra-alveolar localization of SP-A in eight adult human lungs by immunohistochemistry and immunoelectron microscopy. Only type II pneumocytes could be identified as SP-A positive cells within the parenchymal region. SP-A was localized mainly in small vesicles and multivesicular bodies close to the apical plasma membrane. Only few lamellar bodies were weakly labeled at their outer membranes. Stereologic analysis showed this weak signal to be due to specific labeling. In the alveolar space, lamellar body-like surfactant forms in close proximity to tubular myelin were labeled for SP-A at their periphery. The strongest SP-A labeling was found over tubular myelin figures. Labeling for SP-A was also found in close association with the surface film and unilamellar vesicles. Our results support the hypothesis that, in the human lung, SP-A is mainly secreted into the alveolar space via an alternative pathway that largely bypasses the lamellar bodies. After secretion, the outer membranes of unwinding lamellar bodies become enriched with SP-A when tubular myelin formation is initiated. SP-A may also be involved in the transition of tubular myelin into the surface film.