针对Toll样受体4基因的小发夹结构RNA对RAW264.7细胞炎症因子分泌的抑制作用

目的构建针对Toll样受体(TLR)4 mRNA的小发夹结构RNA(shRNA)真核表达载体pEGFP-siRNA/TLR4,检测该shRNA诱导的RNA干扰(RNAi)对脂多糖刺激RAW264.7细胞分泌炎症因子的抑制作用,以探讨针对TLR4基因的RNAi对RAW264.7细胞炎症反应的抑制作用.方法构建携带增强型绿色荧光蛋白(EGFP)及shRNA克隆位点的质粒pEGFP-H1/siRNA,运用网络工具siRNA Wizard(http//www.simawizard.com/)设计针对TLR4 mRNA的寡核苷酸片段.将其克隆入pEGFP-H1/siRNA,构建表达EGFP及TLR4-shRNA的真核表达质粒pEGFP-H1/TLR4-siRNA.运用脂质体转染技术将pEGFP-H1/TLR4-siRNA转染至培养的小鼠巨噬细胞系RAW264.7,观察细胞系中荧光蛋白的表达强度;再运用脂多糖刺激转染的RAW264.7细胞,运用ELISA方法检测该细胞系分泌炎症因子水平的变化.结果质粒pEGFP-H1/siRNA及pEGFP-H1/TLR4-siRNA分别用Bbs Ⅰ和MluⅠ酶切电泳后,前者出现4.9 kb和340 bp的的条带,后者出现5.0 kb和220 bp的条带,与实验设计的质粒长度一致,且测序证实克隆序列正确.将pEGFP-H1/TLR4-siRNA转染至RAW264.7细胞后,EGFP的表达率为50%±8%.用脂多糖刺激后,TLR4-SiRNA转染组细胞培养液TNF-α水平(2 h825 pg/ml±136 pg/ml;8 h2190 pg/ml±359 pg/ml)明显低于对照siRNA转染组(2 h1179 pg/ml±240 pg/ml;8 h4720 pg/ml±227 pg/ml,均P＜0.01).结论针对TLR4 mRNA的shRNA可能通过RNAi机制对脂多糖诱导的RAW264.7细胞炎症因子的分泌有明显的抑制作用.     

Effect of Jianpi Huoxue decoction (健脾活血方)-containing serum on tumor necrosis factor-α secretion and gene Expression of endotoxin receptors in RAW264.7 cells induced by lipopolysaccharide

Objective:To evaluate the effect of Jianpi Huoxue decoction(健脾活血方,JHD)-containing serum on tumor necrosis factor-α(TNF-α) secretion and endotoxin receptor gene expression in RAW264.7 cells induced by lipopolysaccharide(LPS).Methods:The cytotoxicity of blank-control serum and JHD-containing serum at different concentrations were evaluated through the lactate dehydrogenase(LDH) assay in RAW264.7 cells.RAW264.7 cells were divided into six groups:5%blank-control serum group(C1,n=3),5%blank-control serum plus...     

Influence of silencing TRAF6 with shRNA on LPS/TLR4 signaling <Emphasis Type="Italic">in vitro</Emphasis>

This study investigated the influence of silencing TRAF6 with shRNA on lipopolysaccharide(LPS)/toll-like receptor(TLR)-4 signaling pathway in vitro.Four plasmids(pGCsi-TRAF6-shRNA1,2,3,4) containing different shRNA sequences were designed and synthesized.The proliferation of RAW264.7 cells after transfected with these plasmids was measured by MTT assay.Inflammatory cellular models were established by LPS stimulation.Levels of TNF-α,IL-1β and TGF-β1 in the supernatants,mRNA expressions of TRAF6,IL-6 and COX-...     

脂多糖诱导巨噬细胞自噬相关LC3B-GFP荧光聚集体的形成

目的构建pEGFP-C1/LC3B重组质粒并转染小鼠巨噬细胞RAW264.7,观察脂多糖(LPS)诱导其自噬相关LC3B-GFP荧光聚集体形成的过程。方法根据编码小鼠微管相关蛋白1轻链3β(LC3B)的开放读码框(ORF)设计引物,RT-PCR扩增小鼠LC3B的ORF,构建pEGFP-C1/LC3B重组质粒;脂质体法转染并筛选稳定表达RAW264.7细胞株,荧光显微镜观察及Western blot鉴定LC3B-GFP融合蛋白表达;LPS刺激稳定转染的RAW264.7细胞株,激光共聚焦显微镜检测不同时间绿色荧光聚集体的分布。结果成功构建真核表达质粒pEGFP-C1/LC3B,并获得稳定表达LC3B-GFP融合蛋白的RAW264.7细胞株,荧光显微镜下可见细胞内有绿色荧光蛋白分布,Western blot鉴定表达LC3B-GFP融合蛋白,激光共聚焦结果显示LPS刺激前融合蛋白呈弥散性分布在胞浆中,而LPS刺激后细胞内有明显绿色荧光聚集体形成并呈时间依赖性逐渐增加。结论成功构建pEGFP-C1/LC3B,转染RAW264.7细胞可正确表达LC3B-GFP融合蛋白,LPS刺激后显示绿色荧光聚集体形成。     

稳定表达细胞内病原体抗性基因1的RAW264．7细胞克隆的建立

目的：构建携带细胞内病原体抗性基因1（1pr1）,以绿色荧光蛋白（GFP）为报告基因的重组真核表达载体,并导人鼠巨噬细胞RAW264．7中表达．方法：KpnⅠ和BamHⅠ双酶切重组质粒pET32a（＋）-Ipr1及真核表达载体pEGFP-C1,Ipr1基因定向克隆人pEGFP-C1载体,构建重组质粒载体pEGFP-C1-Ipr1．脂质法转染体培养的RAW264．7细胞,在活细胞状态下用荧光显微镜直接观察pEGFP-C1-Ipr1融合蛋白在细胞中的表达;PCR检测Ipr1基因转录水平的表达;West-ernBlot方法验证Ipr1蛋白水平的表达．结果：酶切鉴定获得一条约4700bp空载体条带及一条约1338bp目的片段,证明pEGFP-C1-Iprl真核表达载体构建成功．pEGFP-C1-Ipr1转染RAW264．7细胞后,WesternBlot可以检测到约Mr77×10^3的融合蛋白在RAW264．7细胞中表达,荧光显微镜下可观察到转染细胞中有绿色荧光蛋白表达．结论：成功构建真核绿色荧光蛋白表达载体pEGFP-C1-Ipr1,获得稳定的RAW264．7-Ipr1细胞克隆可表达Ipr1,为进一步研究Ipr1的功能奠定了基础．     

乙酰肝素酶shRNA双基因共表达真核载体的构建和筛选

目的：构建并筛选有效的、编码2条shRNA的乙酰肝素酶（Hpa）特异性基因真核表达载体．方法：分别设计、化学合成6对寡核苷酸单链,经退火、连接和磷酸化后得到Hpa shRNA双链,将两两随机问隔4～8个碱基后定向克隆入带有各自的U6启动子和终止码、共同的绿色荧光蛋白（green fluoreseent protein,EGFP）基因和Neo基因的pGenesil-1中,构建3条含两段Hpa基因shRNA的pGenesil-1-Hpa—shRNA真核表达载体,转染卵巢癌细胞株SKOV3,流式细胞仪和荧光显微镜下观察转染效率,免疫组化分析Hpa蛋白表达．结果：酶切与测序证实pGenesil-1-HPSE—shRNA构建成功,无任何碱基突变,3组质粒转染细胞均有Hpa表达的变化,3种不同shRNA质粒转染细胞后Hpa蛋白表达有明显差别．结论：构建并筛选了针对Hpa特异性的双基因shRNA真核表达载体pGenesil-1-Hpa-shRNA．     

Knocking-down of Nogo-A Gene Expression in PC12 Cell Line by Plasmid-based RNAi

To study the inhibitory effect of Nogo-A shRNA on cell line PC12, the Nogo-A shRNA （short hairpin RNA, or shRNA） was designed and synthesized. The annealed shRNA template was inserted into plasmid pGenesil-1 containing enhanced green fluorescent protein （EGFP） gene by gene cloning technique to generate eukaryotic expression vector. The recombinant plasmid was transfected into PC12 cells by lipofecamine2000 and the mRNA and protein expression level of Nogo-A gene was detected by RT-PCR and Western blotting 48 h after the transfection. Gene sequencing showed that that the Nogo-A shRNA eukaryotic expression vector was successfully constructed. No significant change was found in the Nogo-A mRNA and protein expression level in empty vector-transfected group as compared with controls （P〉0.05）, while the expression level in shRNA-transfected group decreased significantly （P〈0.05）. It is concluded that the pGenesil-1/Nogo-AshRNA recombinant plasmid can effectively suppress the expression of Nogo-A gene in PC12 cells.     

RNA干扰真核表达载体pEGFP-H1介导的血管内皮生长因子shRNA治疗人胶质瘤的实验研究

目的　构建针对血管内皮生长因子(VEGF)的短发夹环RNA(shRNA)质粒(pEGFPH1 /VEGF),观察其在体内和体外对胶质瘤细胞株U251生长的抑制作用。方法　应用PCR构建携带绿色荧光蛋白(EGFP)基因的RNA干扰真核表达载体pEGFP- H1,并利用该载体介导VEGFshRNA。用阳离子脂质体转染U251细胞,通过荧光显微镜和流式细胞仪观察EGFP的表达,用RT- PCR检测VEGFmRNA的表达,以酶联免疫吸附实验(ELISA)检测培养液中VEGF蛋白的含量。同时筛选转染pEGFP- H1和pEGFP- H1 /VEGF的U251稳定细胞株,制备裸鼠U251细胞移植瘤模型,观察肿瘤生长情况。结果　与空载体转染组相比, pEGFP- H1 /VEGF对VEGF的抑制率达77. 9%。对照组和pEGFP -H1组裸鼠肿瘤重量分别为1 .7g±0 4g和1 .5g±0 .7g,体积分别为1573mm3 ±330mm3 和1430mm3 ±382mm3,两组之间重量和体积差异均无统计学意义(P>0 .05 ),而pEGFP- H1 /VEGF组肿瘤重量为0 .5g±0 .4g,体积为401mm3 ±272mm3,与对照组比较差异有统计学意义(P<0. 01)。结论　pEGFP H1介导的VEGFshRNA能有效抑制U251细胞中VEGF的表达,并在体内抑制肿瘤生长。     

Reversal of Multi-Drug Resistance by Vector-Based-ShRNA-Mdr1 In Vitro and In Vivo

In order to investigate the effects of vector-based hairpin small interference RNA (shRNA) on the reversal of multi-drug resistance (mdr) of A2780/Taxol cells, a novel vector pEGFP-H1/mdr1 containing mdr1-shRNA targeting at position 2943-2963 of mdr1 was designed and synthesized.Subsequently, A2780/Taxol cells were transfected with pEGFP-H1/mdrl, and the expression of mdr1 mRNA and P-gp was detected by using RT-PCR and Western blot respectively. MTT was used to measure the 50% inhibition concentration (1C50) of Taxol to A2780/Taxol cells. The results showed that at the 24th and 48th h after transfection, the expression of mdr1 mRNA was decreased to (52.1±1.0)% and (0.01+1.7)%, and that of P-gp decreased to (88.3±2.1)% and 0%, respectively. At the 48th h after transfection, the relative reversal rate of A2780/Taxol cells to Taxol was 69.54%. In vivo, the nude mice xenografts were injected with pEGFP-H1/mdrl, and then administrated Taxol.The tumor volume in pEGFP-H1/mdr1-transfected group was significantly reduced as compared with that in blank control group or pEGFP-H1-transfected group (807.20±103.16 vs 1563.78±210.54 or 1480.78±241.24 mm3, both P<0.01). These results suggested that transfection of pEGFP-H1/mdr1 could efficiently down-regulate the expression of mdr1 mRNA and P-gp in A2780/Taxol cells, and effectively restore the sensitivity of A2780/Taxol cells to Taxol both in vitro and in vivo.     

Ad-delE1b55kD-shRNA/Survivin-EGFP的构建及鉴定

目的 构建特异性强,转染率高,针对人Survivin进行RNA干扰的肿瘤增殖型腺病毒载体(Ad-delE1b55kD-shRNA/Survivin-EGFP). 方法将针对人Survivin的shRNA的基因序列及EGFP基因序列克隆至肿瘤增殖型腺病毒穿梭质粒pAd-delE1b55kD;HEK-293细胞中包装出毒得到重组腺病毒Ad-delE1b55kD-shRNA/Survivin-EGFP并测序鉴定.用重组腺病毒感染结肠癌细胞HT-29并检测转染率,用RT-PCR和Western blot分别检测转染后的HT-29细胞中Survivin mRNA和蛋白表达的变化. 结果序列测定证明针对人Survivin的shRNA序列及EGFP序列被成功构建到肿瘤增殖型腺病毒载体中;Ad-delE1b55kD-shRNA/Survivin-EGFP对结肠癌细胞HT-29的转染效率显著高于增殖缺陷型腺病毒载体和脂质体载体(P＜0.01);而对肝细胞的转染率则显著低于对结肠癌细胞株HT-29的转染(P＜0.01).与复制缺陷型腺病毒载体和脂质体载体比较,转染Ad-delE1b55kD-shRNA/Survivin-EGFP后,HT-29细胞中Survivin mRNA拷贝数及蛋白表达显著降低(P＜0.01).结论 构建成功携带针对人Survivin的shRNA的肿瘤增殖型腺病毒载体Ad-delE1b55kD-shRNA/Survivin-EGFP,其能选择性地高效转染结肠癌细胞株HT-29并有效干扰Survivin,且较之增殖缺陷型腺病毒载体和脂质体载体具有更高的干扰效率.     

用于分子影像学研究的双融合报告基因表达载体的构建及功能验证

目的 构建增强型绿色荧光蛋白(EGFP)和人转铁蛋白受体(TfR)双融合报告基因表达载体,并进行功能鉴定,为活体光学/磁共振双模式成像提供实验基础.方法 将TfR基因克隆到pEGFP-C1载体,构建重组pEGFP-C1 -TfR质粒.pEGFP-C1 -TfR质粒转染293T细胞48 h后,通过荧光显微镜观察EGFP的表达情况;通过RT-PCR检测TfR的表达情况;通过激光共聚焦扫描显微镜检测EGFP-TfR融合蛋白的亚细胞定位;通过Tf探针摄取和竞争实验检测EGFP-TfR融合蛋白的功能.结果 测序结果显示,EGFP-TfR基因序列正确,无突变或缺失.重组质粒转染293T细胞后,荧光显微镜下观察到EGFP的表达;RT-PCR结果显示TfR高效表达;EGFP-TfR融合蛋白主要位于细胞膜,并能够特异介导Tf的内吞.结论 EGFP-TfR双融合报告基因表达载体构建成功,并且能够高效表达发挥各自的功能,可以用于后续的活体光学/磁共振双模式成像.     

连翘对LPS作用的巨噬细胞TLR4蛋白表达的影响

目的观察连翘对LPS诱导巨噬细胞（RAW264．7）16h后TLR4蛋白表达的影响,探讨连翘对抗内毒素作用及其可能机制。方法体外实验共分6组,分别为control组,LPS组,连翘高、中、低剂量组及多黏菌素B组;连翘高、中、低剂量组及多黏菌素B组分别加入连翘水煎液50mg／ml、25mg／ml、12．5mg／ml及多黏菌素B10ug／ml培养0．5h后,再加入10ng／ml LPS,培养16h;Western blot法测各组细胞TLR4蛋白表达变化。结果control组RAW264．7细胞只表达少量TLR4,给予LPS刺激16h,TLR4表达明显升高（P〈0．01）,连翘高、中、低剂量组预处理均可明显降低TLR4的表达（P〈0．01）,并呈剂量依赖关系;连翘高剂量组与多黏菌素B组比较无显著性差异（P〉0．05）。结论连翘预处理能抑制LPS诱导的巨噬细胞TLR4的表达可能是其抗内毒素作用的重要机制。     

免疫抑制剂对酵母聚糖诱导巨噬细胞Dectin-1、Toll样受体2及肿瘤坏死因子-α表达的影响

目的  研究霉酚酸酯和环孢素A对酵母聚糖（Zymosan A）诱导小鼠RAW264.7巨噬细胞模式识别受体Dectin-1、Toll样受体2（TLR2）表达及细胞因子肿瘤坏死因子-α（TNF-α）释放的影响。方法  体外培养RAW264.7巨噬细胞,分别给予不同浓度的霉酚酸酯、环孢素A预处理细胞24 h,再利用100μg/ml Zymosan A单独刺激细胞,逆转录聚合酶链反应和流式细胞术检测细胞Dectin-1、TLR2 mRNA和蛋白水平的变化,酶联免疫吸附试验检测上清液中TNF-α浓度的变化。结果  Zymosan A单独作用巨噬细胞Dectin-1、TLR2 mRNA和蛋白水平明显上调,TNF-α浓度升高（P <0.05）。Zymosan A作用于霉酚酸酯或环孢素A预处理24 h的巨噬细胞Dectin-1、TLR2 mRNA和蛋白水平较Zymosan A单独作用组明显下调,TNF-α分泌量减少（P <0.05）。结论  霉酚酸酯和环孢素A抑制巨噬细胞Dectin-1和TLR2的转录和翻译,并下调TNF-α的释放,降低机体对真菌病原体的清除能力,这可能是应用霉酚酸酯和环孢素A引起难控性真菌感染的机制之一。

     

靶向沉默人基因MDC1 表达对食管癌细胞放射增敏作用的实验研究

目的 利用RNA干扰技术抑制食管癌细胞ECA109细胞MDC1基因表达,观察其对细胞周期和放射敏感性的影响.方法 构建MDC1基因的干扰质粒pMDC1-shRNA,与慢病毒包装质粒混合物共同转染293T细胞,收集病毒液,感染ECA109细胞,采用Real-Time PCR和western blotting测定MDC1在mRNA水平和蛋白水平的表达.采用流式细胞术和克隆形成实验,检测RNA干扰对ECA109细胞放射敏感性的影响.结果 成功构建pMDC1-shRNA质粒,转染ECA109细胞.获得稳定转染细胞株ECA109/MDC1,基因MDC1在mRNA水平和蛋白水平的表达均明显降低;5 Gy射线照射后12 h、24 h、48 h,ECA109/MDC1的G2M期比例明显低于阴性对照组和空白对照组;ECA109、ECA109/NEGATIVE、ECA109/MDC1细胞的D0值分别为3.06 Gy、2.90 Gy、1.88 Gy;SF2值分别为0.91、0.89、0.84;Dq值分别为1159、1.47、1.20,显示ECA109/MDC1的D0值、SF2值、Dq值均明显降低.结论 RNAi技术可以有效地抑制食管癌细胞ECA109中基因MDC1的表达,从而增强ECA109细胞对放射线的敏感性.     

人颗粒溶素与EGFP基因融合表达载体的构建及其在鼠巨噬细胞RAW264.7中的表达

目的:克隆人天然颗粒溶素(granulysin,GLS)的编码序列并构建与绿色荧光蛋白(EGFP)基因融合的真核表达载体,观察人GLS在鼠巨噬细胞株RAW264.7中的表达.方法:提取培养并经同种异型抗原激活的人细胞毒性T淋巴细胞(CTL)细胞总RNA,经逆转录后以套式PCR方法扩增出GLS的编码序列,插入pEGFP-C1质粒,鉴定正确后转染RAW264.7细胞,采用荧光显微镜及RT-PCR法检测融合蛋白及GLS的表达,采用免疫细胞化学法确证表达产物的免疫反应性.结果:成功扩增出了人GLS完整编码序列的cDNA,经PCR及酶切、测序鉴定证明得到了读码框正确的融合蛋白重组子并在靶细胞中得到了成功表达,表达产物具有良好的免疫反应性.结论:人天然GLS能够在鼠巨噬细胞株RAW264.7中以融合蛋白的形式表达,其表达产物具有良好的免疫反应性.     

CXCR4短发夹shRNA表达质粒的构建

目的构建趋化因子受体CXCR4shRNA质粒重组体,并进行序列分析,为下一步探索肿瘤基因治疗的新途径打好基础.方法设计有小发夹结构的两条DNA序列.经退火成互补双链,再克隆至Psilencer2.1-U6 neo质粒载体中构建重组体,转化DH5a菌株,提取质粒行酶切鉴定后,进行测序分析.结果成功构建了CXCR4hRNA质粒重组体.结论CXCR4 shRNA质粒重组体的成功构建为研究CXCR4靶向RNA干扰抗肿瘤的作用打下基础.     

靶向C基因的shRNA抗乙型肝炎病毒在BHK-21细胞中的复制与表达

目的 研究靶向乙型肝炎病毒(HBV)C基因的shRNA(shRNA)诱导RNAi(RNAi)在BHK-21细胞中抑制HBV的复制与表达及抗病毒效果.方法 根据成都军区昆明总医院传染病中心克隆测序的中国56个民族CHB患者HBV基因组(基因型B属ayw1亚型)已在GenBank登录注册:CYN/2002和CYN/2000(GenBank登录号AY517488,AY517489,等),为了监测siRNA功能提供报告基因系统,将HBV C基因PCR产物克隆构建成报告基因表达载体pC-EGFP-N1和载体pCDNA3.1B(-),设计并构建两个靶向同源(CYN/2002和CYN/2000)毒株HBV C基因的长24核苷酸(nt)的shRNA表达质粒(S1和S2),随机设计的用于对照的非同源长24 nt的shRNA表达质粒S3,将其克隆到载体pU6上,构建成表达目的 shRNA重组表达载体,并与pC-EGFP-N1共转染BHK-21细胞.首先在BHK-21细胞中使用BH-2型荧光显微镜观察和FACS-440型流式细胞仪检测绿色荧光蛋白(EGFP)表达细胞数量,评估该shRNA表达质粒在转染后不同时间对C基因/EGFP融合报告基因表达的抑制作用,接着在BHK-21细胞中通过实时荧光定量PCR(RT-PCR)进一步检验了shRNA抗病毒效果.结果 通过BH-2型荧光显微镜观察和FACS-440型流式细胞仪检测,发现在shRNA表达质粒和pC-EGFP-N1共转染BHK-21细胞24 h后,与pC-EGFP-N1或pEGFP-N1单质粒转染相比,S1或S2的共转染组、S1+S2的共转染组使EGFP的表达水平降低了90%,而对照质粒S3或pU6共转染组无显著降低EGFP的表达水平,差异有统计学意义(P＜0.01);应用RT-PCR检测C基因mRNA和EGFP基因mRNA的表达量,结果与BH-2型荧光显微镜和FACS-440型流式细胞仪检测结果相吻合,差异有统计学意义(P＜0.01).进一步证实了RNAi抗病毒效果,抗病毒效应持续时间超过48 h.结果 发现,创建的靶向C基因的shRNA能够有效特异地抗C-EGFP基因在BHK-21细胞中的复制与表达.结论 靶向C基因的RNAi技术能够有效特异地抗HBV在BHK-21细胞中的复制与表达.RNAi可能成为抗重大传染病HBV/HCV安全有效的应急疫苗.     

Reversal of multi-drug resistance by vector-based-ShRNA-Mdr1 <Emphasis Type="Italic">In Vitro</Emphasis> and <Emphasis Type="Italic">In Vivo</Emphasis>

In order to investigate the effects of vector-based hairpin small interference RNA （shRNA） on the reversal of multi-drug resistance （mdr） of A2780/Taxol cells, a novel vector pEGFP-HI/mdrl containing mdrl-shRNA targeting at position 2943-2963 of mdrl was designed and synthesized. Subsequently, A2780/Taxol cells were transfected with pEGFP-H1/rndrl, and the expression ofmdrl mRNA and P-gp was detected by using RT-PCR and Western blot respectively. MTT was used to measure the 50% inhibition concentration （IC50） of Taxol to A2780/Taxol cells. The results showed that at the 24th and 48th h after transfection, the expression of mdrl mRNA was decreased to （52.1±1.0）% and （0.01±1.7）%, and that of P-gp decreased to （88.3±2.1）% and 0%, respectively. At the 48th h after transfection, the relative reversal rate of A2780/Taxol cells to Taxol was 69.54%. In vivo, the nude mice xenografts were injected with pEGFP-H1/mdrl, and then administrated Taxol. The tumor volume in pEGFP-H1/mdrl-transfected group was significantly reduced as compared with that in blank control group or pEGFP-Hl-transfected group （807.20±103.16 vs 1563.78±210.54 or 1480.78±241.24 mm^3, both P〈0.01）. These results suggested that transfection of pEGFP-HI/mdrl could efficiently down-regulate the expression of mdrl mRNA and P-gp in A2780/Taxol cells, and effectively restore the sensitivity of A2780/Taxol ceils to Taxol both in vitro and in vivo.     

Lentivector-mediated RNAi efficiently downregulates expression of murine TNF-α gene in vitro and in vivo

In order to explore the role of TNF-α in Niemann-Pick type C （NPC） disease, lentiviral-delivered RNA interference （RNAi） was used to silence the expression of murine TNF-α gene in vitro and in npc mice. Interference efficiency of the lentivirus expressing TNF-α-siRNA, previously constructed with the concentration of 2 x 108 ifu/mL, was determined by RT-PCR and ELISA in BV-2 cells and astrocytes. At the same time, the constructed Lenti-TNF-α-siRNA was intracerebroventricularly infused into 4-week old npc mice for a 4-week period, and the mice were divided into 3 groups： Lenti-TNF-α-siRNA （n=6）, control lentivirus （n=6）, and NPC mice without any intervention （n=4）. By using immunohistochemistry and real-time PCR, the down-regulation of the target genes was detected. The Lenti-TNF-α-siRNA downregulated the expression of murine TNF-α gene efficiently in vitro and the interference efficiency was 66.7%. Lentivirus could be expressed stably for long-term in the npc mice brain. Immunohistochemistry and real-time PCR revealed that, as compared with non-intervention group and Lenti-control group, Lenti-TNF-α-siRNA efficiently down-regulated the expression of murine TNF-α gene with the interference efficiency being 66.9%. TNF-α-siRNA downregulated the expression of TNF-α gene in vitro and in vivo, which provided a potential tool for studying and treating neurodegenerative diseases and TNF-α-related diseases.