白藜芦醇对胶质瘤U87细胞MMP-2表达和活性水平的影响

目的 探讨白藜芦醇对胶质瘤U87细胞基质金属蛋白酶(MMP)-2表达和活性水平的影响.方法 采用明胶酶谱实验和免疫印迹实验分别检测白藜芦醇对胶质瘤U87细胞MMP-2活性水平和蛋白表达水平的影响;细胞免疫化学实验检测白藜芦醇对U87细胞核因子kappa B(NF-κB)转录活性的影响.结果 明胶酶谱实验显示,40 μM白藜芦醇处理U87细胞4h、24 h和48 h后,MMP-2的活性水平明显降低(P＜0.05);免疫印迹实验证实,40μM白藜芦醇能够明显降低U87细胞MMP-2的蛋白表达水平(P＜0.05);细胞免疫化学结果表明,经40 μM白藜芦醇处理后,p65从胞浆向胞核的转位明显减少(P＜0.05).另外,应用NF-κB抑制剂SN50处理细胞后,MMP-2的蛋白表达水平和活性水平均下降(P＜0.05).结论 40 μM白藜芦醇能够明显抑制U87细胞MMP-2的蛋白表达水平和活性水平,其机制可能与白藜芦醇抑制了NF-κB的转录活性相关.     

血管紧张素-(1-7)对大鼠脑缺血再灌注损伤后核因子-κB及下游炎症因子的调控作用

目的 探讨血管紧张素-(1-7)[Ang-(1-7)]对大鼠脑缺血再灌注损伤后核因子-κB(NF-κB)及其下游炎症因子的调控作用. 方法 将42只SD大鼠按随机数字表法分为假手术组、缺血组及Ang-(1-7)治疗组,每组各14只.缺血组及Ang-(1-7)治疗组均行大脑中动脉栓塞术(MCAO).用微型渗透泵分别给予假手术组及缺血组人工脑脊液(aCSF)0.5 μL/h治疗,给予Ang-(1-7)治疗组Ang-(1-7)(100 pmol/L,0.5 μL/h)治疗.脑缺血再灌注损伤后24 h用Western blotting法检测各组大鼠缺血侧皮层细胞核内NF-κB p65蛋白的表达,免疫组化染色检测NF-κB p65的空间分布以及阳性细胞数,酶联免疫吸附测定(ELISA)法测定血清肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)含量. 结果 Ang-(1-7)治疗组缺血侧顶叶皮层细胞核内NF-κB p65蛋白较缺血组降低约46％,差异有统计学意义(P＜0.05).Ang-(1-7)治疗组缺血侧皮层细胞NF-κB p65由胞浆向胞核的移位被显著抑制,NF-κB p65阳性表达率较缺血组降低约29％,差异有统计学意义(P＜0.05).Ang-(1-7)治疗组缺血侧皮层炎症因子TNF-α、IL-1β的表达[(71.603±18.539) pg/mL、(44.648±10.387) pg/mL]较缺血组[(104.763±24.412) pg/mL、(64.787±14.441) pg/mL]均有所降低,差异有统计学意义(P＜0.05). 结论 Ang-(1-7)能显著减轻脑缺血再灌注损伤中的炎症反应,其可能通过作用于Mas受体或拮抗血管紧张素Ⅱ的促炎作用,进而减轻氧化应激反应而实现.     

Suppression of NF-κB p65 nuclear translocation and tumor necrosis factor-α by Pongamia pinnata seed extract in adjuvant-induced arthritis

Abstract

Pongamia pinnata is a plant known for its therapeutic usage in Indian traditional medicine. Despite the controversy regarding toxic flavonoid and erucic acid content, the seed of this plant is consumed in tribal medicine and its oil is used in Ayurveda to treat psoriasis and arthritis. This study explored the potential anti-arthritic effects of a P. pinnata seed (hexane) extract (PSE) at non-lethal doses in an adjuvant-induced arthritic rat model; possible mechanisms of any observed effects were also explored. After establishing the lethal doses arising from oral exposure to the extract, the material was administered per os daily at two doses (0.3?g/kg/day; 0.5?g/kg/day) to arthritic rats. Other rats received indomethacin or vehicle (control). Treatments were performed for a total of 14 days. One day after the final exposure, the rats were euthanized to permit harvest of various cells, blood, and tissues for analyses. Paw diameter and tissue myeloperoxidase activity in the paws were evaluated as indices for edema and neutrophil infiltration into the tissue. The severity of arthritis in the experimental rats was assessed via measures of urinary hydroxyproline (HP) and glucosamine, and of serum pro-inflammatory TNFα and anti-inflammatory IL-10. The extent of NF-κB p65 nuclear translocation in peritoneal macrophages harvested from naïve rats and then treated in vitro was also assessed. The results indicated that exposure to PSE significantly decreased paw diameter, tissue myeloperoxidase level, and levels of urinary HP and glucosamine, as well as of serum TNFα and IL-10 in adjuvant-injected (arthritic) rats. In vitro PSE treatment also resulted in a marked inhibition of NF-κB p65 nuclear translocation in primary cultures of peritoneal macrophages. Thus, PSE appears to be able to prevent experimental arthritis, in part, by helping to maintain the balance between pro- and anti-inflammatory cytokines and by inhibiting NF-κB activation.     

Inhibitors of TLR-4, NF-κB,and SAPK/JNK signaling reduce the toxic effect of lipopolysaccharide on RAW 264.7 cells

The present study was designed to examine and compare the effects of three suppressors on the cytokine response in tandem with examining: the synthesis of inducible forms of heat shock proteins; HSP72 and HSP90α; activities of NF-κB and SAPK/JNK signaling pathways; and TLR4 expression. Pre-treatment with inhibitors offers promise as protective means to lower the activity of these cascades, thereby circumventing the formation of excessive amounts of pro-inflammatory molecules. Three inhibitors of TLR4, SAPK/JNK, and NF-κB signaling, namely CLI-095, SP600125, and IKK Inhibitor XII, respectively, were added to cultured RAW 264.7 macrophages before the Escherichia coli lipopolysaccharide (LPS) application. Treatments of RAW 264.7 cells with each of the inhibitors resulted in a reduced response to LPS as was visualized by a decrease of TNF-α, IL-1, and IFN-γ production. In addition, inhibitors of the NF-κB and SAPK/JNK signaling reduced IL-6 production in LPS-treated cells, whereas the IKK inhibitor XII also decreased IL-10 production. Further, the NO production in LPS-stimulated macrophages was significantly reduced following application of CLI-095 or IKK inhibitor XII. The results also showed that the inhibitors suppressed TLR4 production and decreased phosphorylation of NF-κB and SAPK/JNK proteins, thereby preventing the activation NF-κB and SAPK/JNK signaling pathways in LPS-activated cells. In addition, the production of inducible heat shock proteins, HSP72 and HSP90-α, was reduced in LPS-stimulated RAW 264.7 cells pre-treated with inhibitors. These results suggest that inhibitors CLI-095, SP600125, and IKK inhibitor XII demonstrate potential effectiveness in the reduction of the inflammatory response by mechanisms involving both the cellular defense system and cellular signaling. In conclusion, suppressor of NF-κB cascade, IKK inhibitor XII, seems to be the most effective anti-toxic agent among studied inhibitors.     

TNF-α及LPS刺激下牙周膜干细胞IκB磷酸化及其下游基因的表达

目的:研究TNF-α及LPS刺激下牙周膜干细胞IκB磷酸化及其下游基因的表达.方法:体外分离、培养人牙周膜干细胞,分别在10 ng/mL TNF-α和500 ng/mL Ecoli.LPS刺激下进行培养,并于刺激培养即时(0 h)、5、30 min和1、2h,采用Western Blot法检测IκBα总蛋白和磷酸化IκBα蛋白的表达变化;Real-time PCR检测IL-6、IL-8 mRNA的表达水平.结果:牙周膜干细胞在10 ng/mL TNFα或500 ng/mL Ecoli.LPS刺激下培养0～2h不同时间后,IκBα总蛋白随刺激时间逐渐降低,1h时最低;磷酸化IκBα随刺激时间逐渐升高,2h时最高;NFκB的下游基因IL-6及IL-8mRNA表达水平均随刺激时间逐渐升高,2h时升高最明显(P＜0.05).结论:炎症细胞因子TNF-α或LPS均可促进牙周膜干细胞中IκBα蛋白的磷酸化,并上调IL-6、IL-8 mRNA的表达;提示NFκB信号通路的活化可能是导致炎症状态下牙周膜干细胞功能损害的重要因素.     

SIRT1抑制炎症反应的研究进展

SIRT1是在人类细胞中广泛存在的一种Sirtuin家族的组蛋白去乙酰化酶,参与了糖脂代谢、衰老等众多生理功能的调节。近年来的研究发现,在炎症反应中,SIRT1能够通过抑制多条细胞信号通路发挥抗炎作用。本文就SIRT1的生物学特性、抗炎作用SIRT1对下游炎症信号通路的抑制作用等做一综述。     

肝复康药物血清对肝星状细胞核因子-κB及I、Ⅲ型胶原表达的影响

目的:通过观察中药肝复康中剂量浓度含药血清对肝星状细胞T6(hepatic stellate cell-T6,HSC-T6)细胞株中核因子-κB(NF-κB)、Ⅰ型胶原(TypeⅠCollagen,ColⅠ)及Ⅲ型胶原(TypeⅢCollagen,ColⅢ)基因表达的影响,探讨其抗纤维化的作用及分子机制。方法:常规方法制备肝复康中剂量浓度含药血清,并用肝复康含药血清干预,以逆转录聚合酶链反应(RT-PCR)和Western-Blot方法观察分析NF-κB、ColⅠ和ColⅢ表达的变化并探讨其相关性。结果:经乙醛刺激后的HSC-T6细胞株NF-κB、ColⅠ和ColⅢ表达均上调,肝复康中剂量浓度含药血清处理后可明显下调上述基因的表达。结论:中药肝复康抗纤维化的机制可能与其抑制NF-κB及ColⅠ、ColⅢ的表达有关。     

塞来昔布联合p65miRNA抑制人乳腺癌移植瘤的生长

目的探讨下调核因子NF-κB p65亚基的表达联合塞来昔布对人乳腺癌裸鼠移植瘤生长的协同抑制效应及其机制。方法建立人乳腺癌裸鼠移植瘤模型,随机将裸鼠分为6组,control组、Neg-miRNA组、p65miRNA组、塞来昔布组、塞来昔布+Neg-miRNA组、塞来昔布+p65miRNA组。观察治疗前后裸鼠的一般状态、肿瘤体积和瘤重,计算平均抑瘤率。免疫组化法检测p65miRNA干扰后肿瘤组织中p65蛋白的表达。RT-PCR、Western印迹法检测肿瘤组织中血管内皮生长因子(VEGF)、金属基质蛋白酶(MMP-2)基因mRNA及蛋白表达的变化。结果塞来昔布组、p65miRNA组和塞来昔布+p65miRNA组肿瘤生长受到明显抑制,抑瘤率分别为43.23%、40.72%及61.69%。p65miRNA组较对照组p65蛋白表达明显减少。塞来昔布组、p65miRNA组和塞来昔布+p65miRNA组VEGF、MMP-2 mRNA及蛋白表达受到不同程度地抑制。结论塞来昔布及p65miRNA均具有明显的抗肿瘤作用,联合应用时具有一定的协同作用,可显著抑制人乳腺癌裸鼠移植瘤的生长,并可显著下调VEGF、MMP-2的表达。     

阿托伐他汀在大鼠颈总动脉球囊损伤模型中对NF-κB及其相关炎性因子的影响

目的研究阿托伐他汀在大鼠颈总动脉球囊损伤模型中对核转录因子NF-κB及其相关炎性因子:细胞间细胞黏附分子1(ICAM-1)、血管细胞黏附分子1(VCAM-1)、单核细胞趋化蛋白1(MCP-1)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)的影响。方法健康雄性Wistar大鼠72只,体重300～350 g,随机分为3组,阿托伐他汀干预组为实验组,通过灌胃法给予阿托伐他汀[10 mg/(kg.d)];安慰剂对照组为模型组,给予等量清水;空白对照组为假手术组,只分离出左颈总动脉后缝合,不作球囊损伤处理,给予等量清水。药物干预3天后实验组与模型组行左侧颈总动脉内膜球囊损伤术,术后实验组继续每日给予阿托伐他汀,模型组及假手术组给予等量清水,每组中各有6只于术后1、3、7天和14天分别处死,采集血清及颈总动脉标本。采用组织形态学观察内膜增生,采用免疫组织化学及酶联免疫吸附试验检测NF-κB及ICAM-1、VCAM-1、MCP-1、IL-6、TNF-α等炎性因子的表达。结果阿托伐他汀组球囊损伤后内膜增生面积显著小于模型组(P<0.01);模型组血管壁及血清中NF-κB及炎性因子ICAM-1、VCAM-1、MCP-1、IL-6、TNF-α的表达显著高于假手术组;阿托伐他汀组血管壁及血清中NF-κB及炎性因子ICAM-1、VCAM-1、MCP-1、IL-6、TNF-α的表达显著低于模型组(P<0.01)。结论阿托伐他汀能抑制大鼠颈总动脉损伤后的内膜增生,其可能机制是通过特异性抑制炎症关键调节因子NF-κB,从而减少其下游炎性因子ICAM-1、VCAM-1、MCP-1、IL-6及TNF-α的表达而实现的。