中波紫外线诱导HaCaT细胞凋亡与扇贝多肽的影响：肿瘤坏死因子α/肿瘤坏死因子受体1通路的研究

背景：扇贝多肽可以通过Fas通路及NF-κB通路发挥对中波紫外线照射后的人角质形成细胞株（HaCaT）的保护作用。目的：观察中波紫外线辐射后HaCaT细胞的凋亡情况和细胞内肿瘤坏死因子α/肿瘤坏死因子受体1的活化情况,以及扇贝多肽的干预作用。方法：实验以20mJ/cm^2中波紫外线辐照HaCaT细胞0.5h建立细胞辐射损伤模型,药物低、中、高剂量组、阳性对照组、抑制剂组分别在造模前2h加入1.42,2.84,5.69mmol/L的扇贝多肽、5.68mmol/L的维生素C及50mg/L的抗肿瘤坏死因子α单克隆抗体。结果与结论：中波紫外线辐照后,HaCaT细胞凋亡增多,肿瘤坏死因子α、肿瘤坏死因子受体1 mRNA及磷酸化JNK蛋白表达量增加;1.42,2.84,5.69mmol/L的扇贝多肽均可降低中波紫外线辐照引起的细胞内肿瘤坏死因子α、肿瘤坏死因子受体1 mRNA及磷酸化JNK表达,抑制HaCaT细胞凋亡,以5.69mmol/L扇贝多肽的作用效果最明显,与5.68mmol/L维生素C的作用相当,且50mg/L抗肿瘤坏死因子α单克隆抗体也可明显降低中波紫外线辐照引起的细胞内磷酸化JNK表达。说明扇贝多肽能抑制中波紫外线辐照引起的HaCaT细胞凋亡,其可以通过肿瘤坏死因子α/肿瘤坏死因子受体1通路发挥抗凋亡作用。     

肿瘤坏死因子样微弱凋亡诱导因子对骨关节炎软骨细胞作用实验研究

目的研究肿瘤坏死因子样微弱凋亡诱导因子（TWEAK）对体外培养骨关节炎（OA）软骨细胞的作用,同时探讨炎性细胞因子白细胞介素-1β（IL-1β）和肿瘤坏死因子α（TNF-α）与TWEAK之间的关系。方法体外培养OA患者原代软骨细胞,分别用TWEAK（75ng/mL）,TWEAK（75ng/mL）和IL-1β（5ng/mL）,TWEAK（75ng/mL）和TNF-α（5ng/mL）作用细胞48h,MTT检测细胞因子对软骨细胞的增殖作用影响;ELISA检测细胞培养上清液中MMP-13、IL-6和Fas的分泌表达。结果 MTT结果表明细胞因子刺激软骨细胞后对细胞增殖无明显影响。TWEAK和IL-1β组诱导MMP-13表达增加（P〈0.05）;TWEAK和IL-1β组,TWEAK和TNF-α组均诱导IL-6表达增加（P〈0.05）。3组Fas分泌表达差异无统计学意义（P〉0.05）。结论 IL-1β与TWEAK,TNF-α与TWEAK分别诱导OA软骨细胞MMP-13和IL-6表达增加,可能参与关节软骨损伤和OA的病程发展。     

肿瘤坏死因子α诱导人髓核细胞凋亡的作用途径

背景:在与细胞凋亡有关的众多因素中,肿瘤坏死因子(tumor necrosis factor,TNF)超家族成员发挥了重要的作用.但TNF是通过何种途径诱导椎间盘髓核细胞凋亡的机制尚未阐明.目的:探讨TNF-α激活后,丝裂原活化蛋白激酶(mitogen-activated protein kinases,MAPKs)信号转导通路中P38MAPK和应激活化蛋白激酶/c-Jun氨基末端激酶(stress-activated protein kinase/c-Jun NH2-terminal kinase,JNK/SAPK)两条途径对人髓核细胞凋亡的作用.方法:体外培养人髓核细胞,将细胞随机分成4组:TNF-α刺激组,P38MAPK阻断组,P-JNK/SAPK阻断组和对照组.采用TUNEL法检测髓核细胞凋亡情况,免疫荧光法检测P-P38MAPK和P-JNK/SAPK的表达及定位:Western Blot法检测P38MAPK,JNK/SAPK及其磷酸化形式的表达.结果与结论:TUNEL法检测凋亡结果中,TNF-α刺激组较其他各组的凋亡细胞密度大(P＜0.01);免疫荧光结果显示TNF-α刺激组P-P38MAPK和JNK/SAPK在细胞质和细胞核的表达高于各阻断组和对照组(P＜0.01);Western Blot结果显示P38MAPK,P-JNK/SAPK在各组髓核细胞内均有表达,但无活化形式,TNF-α刺激组可见P-P38MAPK,P-JNK/SAPK表达,但相应阻断组无表达.结果表明,外源性TNF-α可通过P38MAPK和P-JNK/SAPK途径导致人髓核细胞凋亡.     

肿瘤坏死因子-α与胎膜早破

目的 探讨肿瘤坏死因子（TNF）-α在胎膜早破发病机制中的作用及意义。方法 采集无任何妊娠并发症、临产前要求剖宫产分娩的初产妇（包括19例足月胎膜早破、15例足月前胎膜早破和作对照的17例正常未破膜者）血、羊水及胎膜，用双抗体夹心酶联免疫吸附实验法测定血清、羊水中TNF-α的浓度，胎膜常规苏木素-伊红染色后行组织病理学检查及TUNEL技术精确标记后细胞凋亡指数的测定。结果 ①胎膜早破组血清、羊水中TNF-α浓度明显高于对照组，差异有显著性（P〈0.05或〈0.01）；且胎膜早破组胎膜感染的发生率和胎膜的细胞凋亡指数也较对照组高，差异有显著性（P〈0.05或〈0.01）；但足月和足月前胎膜旱破两组间血清、羊水中TNF-α浓度、胎膜感染率和细胞凋亡指数差异均无显著性（P〉0.05）。②胎膜有感染组血清、羊水中TNF-α浓度及胎膜细胞凋亡指数明显高于无感染组，差异有显著性（P〈0.01）；在无感染组中胎膜早破的血清、羊水中TNF-α浓度及胎膜细胞凋亡指数也较对照组高，差异有显著性（P〈0．01）。③所有研究对象血清、羊水中TNF-α浓度呈明显正相关（r=0．386，P〈0.01）。结论 TNF-α在胎膜早破发病机制中有促炎、降解细胞外基质、诱导细胞凋亡等功效；神经内分泌免疫网络失衡所致的胎膜细胞凋亡增加可能是胎膜早破的又一发病机制。     

肿瘤坏死因子-α与血沉关系的实验研究

目的探讨肿瘤坏死因子-α(TNF-α)与红细胞沉降率(血沉,ESR)的关系。方法采用酶联免疫吸附测定(ELISA)法测定血清TNF-α及可溶性肿瘤坏死因子受体-Ⅰ(sTNFRⅠ)水平,采用魏氏法测定血沉;体外加入TNF-α、sTNFR-Ⅰ及sTNFR-Ⅱ后魏氏法测定血沉。结果肿瘤患者和糖尿病患者的血清TNF-α、sTNFR-Ⅰ水平及ESR值均显著高于正常对照组,且血清TNF-α、sTN-FR-Ⅰ水平与ESR值之间均有相关关系;ESR值愈大,血清TNF-α、sTNFR-Ⅰ水平愈高;体外加入TNF-α可以使ESR增快。结论TNF-α和sTNFR-Ⅰ与ESR之间存在相关关系,TNF-α和sTNFR-Ⅰ可以影响ESR。     

充血性心力衰竭患者肿瘤坏死因子-α和可溶性肿瘤坏死因子受体Ⅱ变化及其意义

目的　探讨充血性心力衰竭 (CHF)时肿瘤坏死因子 α(TNF α)和可溶性肿瘤坏死因子受体Ⅱ(sTNFRⅡ )的变化及其与CHF的关系。方法　CHF患者 4 5例和年龄匹配的正常对照组 17例 ,根据NY HA分级 ,将CHF患者分成Ⅱ、Ⅲ、Ⅳ级 3组 ;根据体重分成恶病质组及非恶病质组。用酶联免疫法测定sTNFRⅡ ,用放射免疫法测定TNF α。结果　CHF患者血清TNF α和sTNFRⅡ较对照组明显升高 ,TNF α在Ⅲ、Ⅳ级时显著升高 ,sTNFRⅡ在心功能Ⅱ、Ⅲ、Ⅳ级时均显著升高。不同病因的CHF之间TNF α和sTNFRⅡ无显著差异 ,恶病质组及非恶病质组之间无明显变化。血清TNF α与sTNFRⅡ呈正相关 (r =0 .5 14 1,P <0 .0 1)。结论　血清TNF α和sTNFRⅡ水平与CHF的严重程度密切相关 ,可作为判断CHF严重程度及预后的指标。     

肿瘤坏死因子α诱导人成骨细胞和人成骨细胞系HOS-8603凋亡的作用

目的:观察不同浓度重组肿瘤坏死因子α对于培养的人原代成骨细胞和人成骨细胞系HOS-8603的凋亡作用,并分析浓度效应。方法:实验于1998-04/2000-04在第二军医大学卫生毒理学教研室完成。在人成骨细胞和人成骨细胞系HOS-8603中,实验组加浓度为1,10,100,1000ng/L的肿瘤坏死因子α,对照组加等量的无肿瘤坏死因子培养基,培养后检测细胞活力应用噻唑兰法,检测细胞凋亡情况应用DNA梯形条带和透射电镜等方法。结果:①肿瘤坏死因子α对培养成骨细胞和HOS-8603细胞的作用(噻唑兰法):肿瘤坏死因子α浓度为100和1000ng/L实验组均高于对照组犤成骨细胞:(0.14±0.006),(0.10±0.010),(0.27±0.013)ng/L;HOS-8603细胞:(0.15±0.012),(0.09±0.015),(0.27±0.013)ng/L,P<0.05犦。②DNA梯形条带结果:凋亡细胞使DNA在核小体外降解,形成180～200bp或与之成倍的DNA片段。在琼脂糖凝胶电泳时呈现梯形结果。在肿瘤坏死因子α浓度为1000ng/L时,成骨细胞可检测到典型DNA梯形条带。③成骨细胞的凋亡情况:应用透射电镜检查,浓度为1000ng/L实验组较浓度为100ng/L实验组凋亡细胞多。肿瘤坏死因子α同样可以诱导HOS-8603的凋亡,未加肿瘤坏死因子α时,凋亡很少,加入100ng/L及1000ng/L肿瘤坏死因子α时,凋亡细胞数量明显增加。结论:肿瘤坏死因子α质量浓度达到100g/L时,可以引起体外培养的成骨细胞和成骨细胞系HOS-8603细胞凋亡,并随浓度加大出现凋亡细胞增多的剂量-效应关系,结果验证了肿瘤坏死因子能刺激成骨细胞凋亡的假说。     

血清缺氧诱导因子1α和肿瘤坏死因子α及肝细胞生长因子与脑梗死的关系

目的 探讨缺氧诱导因子1α(HIF-1α)、肿瘤坏死因子α(TNF-α)及肝细胞生长因子(HGF)与脑梗死的关系.方法 入选2013年6-12月我院收治的急性脑梗死患者212例作为观察对象,根据脑梗死类型分为进展性脑梗死(PCI)组105例和稳定性脑梗死(SCI)组107例,选取同期100名健康体检人群作为对照,采用酶联免疫吸附法(ELISA)检测3组研究对象的HIF-1α、TNF-α及HGF;将PCI组患者按照神经功能或梗死病灶大小分组,比较各组间HIF-1α、TNF-α及HGF水平差异.结果 PCI组HIF-1α、TNF-α、HGF分别为(2.3±1.3) ng/L、(4.0±0.5)mg/L、(1.4±0.3)μg/L,显著高于SCI组[(1.1±0.5)ng/L、(3.1±1.3) mg/L、(0.7±0.4) μ#L]和健康对照组[(0.5 ±0.1)ng/L、(1.8±0.4)mg/L、(0.4±0.1)μ昏/L],SCI组显著高于健康对照组,差异均有统计学意义(F值分别为3.14、5.42、1.32,P均＜0.01);PCI轻度组患者HIF-1α、TNF-α、HGF分别为(0.7±0.3) ng/L、(2.9±0.3)mg/L、(0.7±0.5)μg/L,均显著低于中度组[(1.4±0.5)ng/L、(4.9±0.5)mg/L、(1.7±0.4)μg/L]和重度组[(1.4±0.5) ng/L、(4.9±0.5)mg/L、(1.9±0.4) μg/L,中度组显著低于重度组,差异均有统计学意义(F值分别为0.93、4.32、2.31,P均＜0.01);PCI小梗死灶组患者HIF-1α、TNF-α、HGF分别为(0.6 ±0.4)ng/L、(2.7 ±0.4)mg/L、(0.7±0.4)μg/L,均显著低于中梗死灶组[(1.1±0.5)ng/L、(4.4±0.5) mg/L、(1.1±0.2)μg/L]和大梗死灶组[(1.4±0.6)ng/L、(4.8±0.6)mg/L、(1.9±0.5)μg/L];中梗死灶组显著低于大梗死灶组,差异均有统计学意义(F值分别为4.71、2.09、2.45,P均＜0.01).结论 进展性脑梗死患者血清HIF-1仪、TNF-α及HGF水平明显增高,且各指标与进展性脑梗死神经功能缺损程度及梗死灶大小关系密切.     

肿瘤坏死因子相关凋亡诱导配体对骨髓基质细胞的毒性作用

背景:已证实肿瘤坏死因子相关凋亡诱导配体(tumor necrosis factor-related apoptosis-inducing ligand,TRAIL)能选择性诱导白血病细胞凋亡,并且不影响正常造血干/祖细胞的功能。但TRAIL对作为造血微环境核心的骨髓基质细胞的毒性作用如何,据作者查新检索目前尚未见系统报道。目的:通过观察TRAIL对骨髓基质细胞的凋亡诱导效应及其造血支持功能的影响,继而评价TRAIL对骨髓基质细胞的毒性作用。设计、时间及地点:细胞学体外对照观察,于2006-03/10在解放军沈阳军区总医院中心实验室完成。材料:血常规、骨髓涂片细胞检查正常的骨髓标本11份,取自解放军沈阳军区总医院血液科。化疗药物柔红霉素为浙江海正药业股份有限公司产品,国药准字H33020925。方法:Percoll 贴壁法体外分离培养骨髓基质细胞,达80%融合时胰蛋白酶消化扩增,取处于对数生长期的细胞,分为4组,空白对照组不进行任何干预,柔红霉素组加入0.5μmol/L柔红霉素作用24h,TRAIL组加入200μg/L TRAIL作用18h,联合组加入0.5μmoL/L柔红霉素作用6h后再以200μg/L TRAIL作用18h。取第2代骨髓基质细胞,60Co射线照射消除内源性造血集落,接种后去除悬浮细胞,TRAIL组以200μg/L TRAIL作用基质细胞层18h,按1×105/孔将骨髓单个核细胞接种于基质细胞层,扩增5d后加入甲基纤维素培养体系,于37℃、体积分数为0.05的CO2饱和湿度条件下培养10d。主要观察指标:荧光显微镜观察诱骗受体在骨髓基质细胞的表达及定位,流式细胞仪检测柔红霉素对骨髓基质细胞诱骗受体表达的影响,AnnexinⅤ/PI标记TRAIL对骨髓基质细胞的凋亡诱导作用及对其造血支持功能的影响。结果:诱骗受体DcR1和DcR2在骨髓基质细胞中均有表达,主要定位于胞膜及胞浆。0.5μmol/L柔红霉素作用24h后,基本不影响诱骗受体DcR1和DcR2的表达水平。与空白对照组细胞凋亡率比较,TRAIL组无明显变化(t=0.973,P>0.05);柔红霉素组、联合组均显著升高(t=5.141,P=0.001;t=4.187,P=0.002),此两组间比较差异无显著性意义(t=1.222,P>0.05)。与空白对照组比较,TRAIL组骨髓单个核细胞数、粒-巨噬集落形成单位均无明显变化(t=1.313,P>0.05;t=1.172,P>0.05)结论:TRAIL的诱骗受体DcR1及DcR2在骨髓基质细胞均有表达,使骨髓基质细胞免于TRAIL的凋亡诱导效应,且TRAIL不增强柔红霉素对骨髓基质细胞的细胞毒性作用。     

肿瘤坏死因子相关凋亡诱导配体诱导的细胞凋亡在再生障碍性贫血发病中的意义

目的通过检测肿瘤坏死因子相关凋亡诱导配体(TRAIL)诱导正常骨髓单个核细胞(BMMNC)凋亡率,及抑制TRAIL凋亡途径后再生障碍性贫血(AA)患者骨髓单个核细胞凋亡率,探讨TRAIL在AA患者骨髓造血细胞凋亡中的作用。方法采用流式细胞术检测43例骨髓象正常者(正常组)及TRAIL作用后(TRAIL组)其骨髓单个核细胞凋亡率;14例AA患者(AA组)及TRAIL抗体作用后(TRAIL-Ab组)其骨髓单个核细胞凋亡率。结果 (1)AA组凋亡率较正常组明显增高,差异有统计学意义(P<0.05)。(2)TRAIL组(浓度为30 ng/ml,作用24 h)凋亡率[(39.98±4.594)%]高于正常组[(19.90±6.656)%],差异有统计学意义(P<0.05)。(3)TRAIL-Ab组凋亡率[(30.28±4.594)%]较AA组[(51.29±7.355)%]减少,差异有统计学意义(P<0.05)。结论一定浓度的TRAIL可使正常骨髓单个核细胞凋亡增加,抑制TRAIL诱导的凋亡途径后,AA患者骨髓单个核细胞凋亡减少,提示TRAIL诱导的细胞凋亡,可能在AA发病中发挥一定作用。     

Tumor necrosis factor receptor regulation of bone marrow cell apoptosis during endotoxin-induced systemic inflammation

Although inflammation-induced release of cells from the bone marrow (BM) is well established, less is known regarding inflammation-induced modulation of bone marrow cell numbers by apoptosis. The purpose of this study is to assess apoptosis of BM immature and mature myeloid cells and peripheral granulocytes, and to elucidate the role(s) of TNFR-p55 and TNFR-p75 as modulators of apoptosis in these cellular compartments in a mouse model of endotoxin-induced systemic inflammation. Gene knockout (p55(-/-), p75(-/-), and p55(-/-)/p75(-/-)), or wild-type (WT) mice were injected i.p. with saline (Sal) or LPS (4 microg/g) followed by collection of BM cells and peripheral blood after 24 h. Apoptosis was assessed by propidium iodide staining using two-color flow cytometry with differentiated granulocyte-specific Gr1-fluorescein isothiocyanate. Repeated-measures analysis of variance and Neuman-Keuls post hoc test were used for statistical analyses. After i.p. LPS, apoptosis was induced to the higher level in BM Gr1(-) cells than in BM Gr1(+) cells and was not induced in peripheral Gr1(+) cells. Depletion of cell numbers in both BM Gr1(-) and Gr1(+) subpopulations after LPS treatment was consistent with increase of the apoptotic cell percentages in the groups. LPS-induced apoptosis was significantly lower in Gr1(-) cells from the -p55(-/-)/LPS and p55(-/-)/p75(-/-)/LPS mice but not from p75(-/-)/LPS mice as compared with WT/LPS mice, whereas there was no difference in apoptosis of BM Gr1(+) and peripheral Gr1(+) cells among WT groups and knockout groups. Thus, apoptosis of myeloid cells during endotoxemia is minimized because these cells undergo differentiation, which in turn may be because of the attenuation of the proapoptotic effect of TNFR-p55 shown herein to occur with myeloid differentiation. In contrast, TNFR-p75 seems to play a minimal role in apoptosis induction in Gr1(-) myeloid cells during endotoxemia. One explanation for a decrease in BM cell numbers during endotoxemia may be via induction of apoptosis in immature myeloid cells.     

Effect of tumor necrosis factor alpha on mitogen-activated human B cells

In this study we demonstrate that the monocyte/macrophage product, tumor necrosis factor alpha (TNF-alpha), has significant in vitro effects of B cell function. It costimulated with anti-mu in the induction of B cell DNA synthesis, and it prolonged the DNA synthesis initiated in B cell cultures stimulated with the human B cell mitogen, Staphylococcus aureus Cowan strain I (SAC). The addition of either IL-1 or IFN-gamma to TNF-alpha resulted in a substantial further increase in DNA synthesis. The addition of TNF-alpha to IL-2, a known inducer of SAC-activated B cell Ig secretion, resulted in a twofold enhancement in the amount of IL-2 stimulated B cell Ig secretion. Receptor binding studies with 125I-TNF-alpha demonstrate a marked increase in TNF-alpha binding sites after B cell activation (approximately 6,000 sites per cell, with an apparent Kd of 2.0 X 10(-10) M). Thus, TNF-alpha may be an important factor in human B cell function and is likely to interact with other T cell and monocyte derived cytokines in the regulation of human B cell proliferation and Ig production.     

病理性瘢痕组织中肿瘤坏死因子受体1和半胱氨酸蛋白酶3对成纤维细胞凋亡的调控

目的:研究肿瘤坏死因子受体1(tumornecrosisfactorreceptor1,TNFR)1和半胱氨酸蛋白酶3(Caspase-3)在病理性瘢痕组织细胞中的表达及其对成纤维细胞凋亡与增殖的影响,进一步探讨瘢痕形成机制。方法:对手术切除的增生性瘢痕,瘢痕疙瘩及正常皮肤各10例应用免疫组织化学方法进行检测,分析TNFR和Caspase-3的表达及分布规1律。结果:TNFR在正常皮肤、增生性瘢痕及瘢痕疙瘩中成纤维细胞的1表达阳性率分别为(11.04±2.52)%,(3.27±1.30)%和(7.67±2.35)%,TNFR在正常皮肤组中的阳性表达率明显高于增生性1瘢痕组和瘢痕疙瘩组,而瘢痕疙瘩组阳性表达率又明显高于增生性瘢痕组,3组间阳性表达率相互比较差异均具有非常显著性意义(F=51.453,P<0.01);Caspase-3在正常皮肤的阳性表达率为(14.84±2.41)%,明显高于增生性瘢痕组(5.05±1.47)%和瘢痕疙瘩组(2.95±1.25)%,3组间阳性表达率相互比较差异亦均具有非常显著性意义(F=161.694,P<0.01)。结论:在细胞凋亡通路中凋亡关键效应子Caspase-3的激活减少及TN-FR介导的死亡受体凋亡通路受阻在病理性瘢痕的形成机制中发挥了1一定的作用;同时,TNFR又可能介导了核转录因子NF-κB的激活,促1进成纤维细胞的增殖,表明TNFR对成纤维细胞的增殖与凋亡具有双1重的调节作用。     

Production of tumor necrosis factor/cachectin by human B cell lines and tonsillar B cells

The production of TNF/cachectin by human B cell lines and tonsillar B cells was examined. Of the 15 B cell lines examined, 9 cell lines synthesize TNF mRNA constitutively. PMA stimulated most cell lines to accumulate increased amounts of TNF. SeD, 8866P, 32al, RPMI 1788, and four bone marrow-derived EBV-transformed cell lines accumulated high levels of TNF mRNA when stimulated by PMA. TNF production by these cell lines was examined. RPMI 1788 and WIH8 produced little TNF constitutively, but synthesized 5-7 ng/ml TNF when stimulated by PMA. A pre-B cell line, Nalm-6, did not synthesize any detectable amount of TNF mRNA, even with PMA stimulation. Tonsillar B cells could also be stimulated to produce TNF. PMA or Staphylococcus aureus Cowan I strain (SAC) alone stimulated some TNF mRNA accumulation, whereas B cell growth factor (BCGF) or anti-mu did not. This accumulation was synergistically elevated by the combinations of PMA and SAC, or PMA and anti-mu. BCGF increased PMA-, SAC-, PMA plus SAC-, or PMA plus anti-mu-induced TNF mRNA accumulations about twofold. The accumulation of TNF mRNA in tonsillar B cells stimulated by PMA plus SAC was between 32 and 48 h, the same peak interval as the accumulation of TNF and IL-2 mRNA in tonsillar T cells. This is in contrast to PMA or PMA plus A23187-stimulated RPMI 1788 cells in which TNF mRNA accumulation was maximal at 1-2 h. TNF activities found in tonsillar B cell supernatants correlated with the TNF mRNA levels in the cells. However, more TNF activity was found on the second-day than the third-day supernatants, indicating active TNF uptake by the B cells. Cyclosporin A (CsA) inhibited SAC and anti-mu responses in B cells in much the same way as the anti-CD3 responses in T cells. SAC-, PMA plus SAC-, and PMA plus anti-mu-stimulated, but not PMA-stimulated, increases in TNF mRNA accumulations in tonsillar B cells were inhibited by CsA. TNF production seems to increase in parallel with B cell proliferation, but the relationship of these two functions needs to be further examined.     

TACI is a TRAF-interacting receptor for TALL-1, a tumor necrosis factor family member involved in B cell regulation

We and others recently reported tumor necrosis factor (TNF) and apoptosis ligand-related leukocyte-expressed ligand 1 (TALL-1) as a novel member of the TNF ligand family that is functionally involved in B cell proliferation. Transgenic mice overexpressing TALL-1 have severe B cell hyperplasia and lupus-like autoimmune disease. Here, we describe expression cloning of a cell surface receptor for TALL-1 from a human Burkitt's lymphoma RAJI cell library. The cloned receptor is identical to the previously reported TNF receptor (TNFR) homologue transmembrane activator and calcium modulator and cyclophilin ligand (CAML) interactor (TACI). Murine TACI was subsequently isolated from the mouse B lymphoma A20 cells. Human and murine TACI share 54% identity overall. Human TACI exhibits high binding affinities to both human and murine TALL-1. Soluble TACI extracellular domain protein specifically blocks TALL-1-mediated B cell proliferation without affecting CD40- or lipopolysaccharide-mediated B cell proliferation in vitro. In addition, when injected into mice, soluble TACI inhibits antibody production to both T cell-dependent and -independent antigens. By yeast two-hybrid screening of a B cell library with TACI intracellular domain, we identified that, like many other TNFR family members, TACI intracellular domain interacts with TNFR-associated factor (TRAF)2, 5, and 6. Correspondingly, TACI activation in a B cell line results in nuclear factor kappaB and c-Jun NH(2)-terminal kinase activation. The identification and characterization of the receptor for TALL-1 provides useful information for the development of a treatment for B cell-mediated autoimmune diseases such as systemic lupus erythematosus.     

TNFα1型受体敲除对小鼠急性后肢缺血的作用

目的研究肿瘤坏死因子α1型受体(tumornecrosisfactorαreceptor1,TNFαR1)信号通路在小鼠急性后肢缺血中的作用,并探讨其作用机制。方法通过结扎TNFαR1/和野生型小鼠股动静脉及其主要分支建立后肢急性缺血模型,激光多普勒测手术前后后肢血液灌流,TUNEL染色观察细胞凋亡,凝胶电泳观察DNA凋亡梯带,免疫蛋白印迹法测定Caspase3、Bax蛋白的表达。结果术后1天TNFαR1/组缺血侧后肢血液灌流显著高于野生型组,腓肠肌TUNEL阳性细胞显著低于野生型组。TNFαR1/组缺血评分则显著低于野生型组,两组的自发截肢率分别为50%、0%。TNFαR1/组DNA凋亡梯带、Caspase3和Bax蛋白表达减弱。结论TNFαR1敲除可抑制TNFα信号通路下游死亡相关蛋白的激活,减少细胞死亡和调亡,对急性后肢缺血有保护作用。     

可溶性肿瘤坏死因子受体对炎性牙周膜细胞的作用

目的:分析可溶性肿瘤坏死因子受体及T淋巴细胞对炎性牙周膜细胞的作用。方法:实验于2005-03/09在解放军第四军医大学口腔医学院口内实验室完成。免疫磁珠分离CD3 T淋巴细胞于解放军第四军医大学唐都医院骨科实验室完成。CD3 T淋巴细胞取自正常人的外周血,牙周膜成纤维细胞和淋巴细胞培养液均购自美国Gbico公司,大肠杆菌内毒素购自Sigma公司,质粒引物合成及目的基因检测均于Takara公司完成。正常牙周膜成纤维细胞与CD3 T淋巴细胞共培养,加入大肠杆菌内毒素,实验组用PcDNA3.1( )-可溶性肿瘤坏死因子受体转染细胞的培养液培养,对照组用转染空质粒的细胞培养液培养。空白组为正常牙周膜成纤维细胞加CD3 T淋巴细胞、正常牙周膜成纤维细胞加内毒素、正常牙周膜成纤维细胞。噻唑蓝法检测各组细胞24h和48h的活力变化;PcDNA3.1( )-可溶性肿瘤坏死因子受体转染细胞后,免疫组化染色强阳性表达,转染培养液培养实验组细胞24h和48h后,噻唑蓝法检测实验组牙周膜细胞的活力变化。结果:①正常牙周膜成纤维细胞与CD3 T淋巴细胞共培养,内毒素刺激正常牙周膜成纤维细胞后,细胞活性降低;培养24h和48h后,噻唑蓝法检测各组的A值:正常牙周膜成纤维细胞和CD3 T淋巴细胞共培养组,加入内毒素刺激,24h为4.6±0.2,48h为3.7±0.1;用PcD-NA3.1( )-可溶性肿瘤坏死因子受体转染细胞的培养液培养,24h为7.8±0.3,48h为6.9±0.5;正常牙周膜成纤维细胞用内毒素刺激,24h为9.0±0.4;48h为8.7±0.3;单纯正常牙周膜成纤维细胞与CD3 T细胞共培养,24h为10.1±0.2,48h为9.8±0.5;单纯培养牙周膜成纤维细胞,24h为10.0±0.5,48h为9.2±0.1。②转染空质粒PcDNA3.1( )的牙周膜成纤维细胞其可溶性肿瘤坏死因子受体表达不明显,而转染质粒PcDNA3.1( )-可溶性肿瘤坏死因子受体的牙周膜成纤维细胞其可溶性肿瘤坏死因子受体表达增强。结论:内毒素与T淋巴细胞刺激正常牙周膜成纤维细胞可以引起肿瘤坏死因子α水平升高;可溶性肿瘤坏死因子受体对于炎症牙周膜成纤维细胞有抑制肿瘤坏死因子α作用的功能。     

Tumor necrosis factor alpha directly and indirectly regulates hematopoietic progenitor cell proliferation: role of colony-stimulating factor receptor modulation

Tumor necrosis factor alpha (TNF-alpha) has been shown to both stimulate and inhibit the proliferation of hematopoietic progenitor cells (HPCs) in vitro, but its mechanisms of action are not known. We demonstrate that the direct effects of TNF-alpha on murine bone marrow progenitors are only inhibitory and mediated at least in part through downmodulation of colony-stimulating factor receptor (CSF-R) expression. The stimulatory effects of TNF-alpha are indirectly mediated through production of hematopoietic growth factors, which subsequently results in increased granulocyte-macrophage CSF and interleukin 3 receptor expression. In addition, the effects of TNF-alpha (stimulatory or inhibitory) are strictly dependent on the particular CSF stimulating growth as well as the concentration of TNF-alpha present in culture. A model is proposed to explain how TNF-alpha might directly and indirectly regulate HPC growth through modulation of CSF-R expression.