电击死心脏窦房结组织纤维连接蛋白的表达

目的通过研究电击死心脏窦房结组织中纤维连接蛋白(Fibronectin,Fn)的蛋白水平,为电击死的诊断及死亡时间鉴定提供新的理论依据。方法采用免疫组化技术(SP法)检测电击死亡人窦房结15例(人电击组)、重度颅脑损伤人窦房结15例(人对照组)、电击死亡兔窦房结35例(兔电击组分7组:0 h、1 h、3 h、6 h、12 h、24 h、48 h)和断颈处死兔窦房结35例(兔对照组分7组:0 h、1 h、3 h、6 h、12 h、24 h、48 h)的Fn蛋白表达水平。结果人电击组Fn阳性表达率为100%,有强弱之分;人对照组Fn阳性表达率为6.67%,组间差异有极显著性统计学意义(P0.01)。兔电击组电击后即刻(0 h)就有Fn表达,与兔对照组相比,差异有统计学意义(P0.05);电击后3 h、6 h至12 h Fn表达分布越来越广泛,与兔对照组比较差异有极显著性统计学意义(P0.01);Fn表达在电击死后24 h逐渐下降,至电击死后48 h仍与兔对照组比较,差异有统计学意义(P0.05),而阴性对照组则未见类似改变。结论电击使窦房结Fn表达明显增强,并且随着死亡时间的延长窦房结Fn蛋白阳性表达的光密度值呈规律性变化,可为法医学电击死诊断和死亡时间的鉴定提供新的理论参考依据。     

妊高征患者子宫静脉血浆对血管内皮细胞膜上纤维结合蛋白的影响

本研究于体外培养的人脐静脉血管内皮中加入妊高征病人子宫静脉血浆，培养一定时间后，免疫组织化学法检测细胞膜上纤维结合蛋白(Fn)。结果发现经妊高征病人子宫静脉血浆处理过的血管内皮表面Fn增加。表明妊高征胎盘能够合成某种因子刺激血管内皮合成Fn；内皮细胞膜上的Fn增多可能是妊高征病人凝血异常的原因。     

IL-6对大鼠血管平滑肌细胞TWEAK受体Fn14表达及功能的影响

目的:观察白介素-6(IL-6)对Wistar大鼠血管平滑肌细胞肿瘤坏死因子样凋亡微弱诱导剂(TWEAK)受体-人成纤维细胞生长因子诱导14(Fn14)表达及功能的影响。方法:将含有不同浓度IL-6(20ng/ml、50ng/ml)的培养液培养平滑肌细胞,用RT-PCR半定量检测各组平滑肌细胞Fn14mRNA的表达,用Westernblot检测各组平滑肌细胞Fn14蛋白的表达。在20ng/mlIL-6组中,用抗Fn14抗体阻断Fn14作用后,用ELISA观察各组血管平滑肌细胞单核细胞趋化蛋白-1(MCP-1)表达的变化。结果:与空白对照组相比,20ng/mlIL-6组和50ng/mlIL-6组Fn14mRNA和蛋白表达均显著升高(P0.01);50ng/mlIL-6组显著高于20ng/ml组(P0.01)。20ng/mlIL-6可显著增加平滑肌细胞表达MCP-1,其水平显著高于抗Fn14单克隆抗体组(P0.05)和空白对照组(P0.01)。结论:IL-6可诱导血管平滑肌细胞表达TWEAK受体Fn14,阻断Fn14的作用可减少IL-6诱导的MCP-1的表达,提示TWEAK/Fn14参与IL-6诱导的动脉粥样硬化形成。     

地塞米松对哮喘小鼠肺组织中TWEAK及其受体Fn14表达的调节作用

目的:探讨地塞米松对哮喘小鼠模型肺组织中肿瘤坏死因子样弱凋亡诱导因子(TWEAK)及受体成纤维细胞生长因子诱导的早期反应蛋白14 (Fn4)表达的调节作用.方法:采用卵清蛋白致敏方法建立经典哮喘模型.将36只雌性BALB/c小鼠,随机分为对照组、哮喘组、地塞米松组,每组12只.HE染色评估各组小鼠气道炎症程度;采用逆转录聚合酶链反应(RT-PCR)方法检测各组肺组织TWEAK、Fn14mRNA表达水平;采用免疫组化方法检测各组肺组织TWEAK、Fn14蛋白表达水平.结果:哮喘组小鼠肺组织TWEAK、Fn14 mRNA水平高于对照组(P＜0.01),地塞米松组TWEAK、Fn14 mRNA水平低于哮喘组(P＜0.01).TWEAK、Fn14蛋白的表达水平哮喘组较对照组明显升高(P＜0.01),地塞米松组表达量较哮喘组明显降低(P＜0.01).结论:地塞米松可抑制哮喘小鼠肺组织中TWEAK及Fn14表达,从而减少气道炎症反应.     

细胞铁代谢变化参与阿司匹林抗氧化作用的调控机制

目的:探讨铁蛋白(Fn)表达及细胞内铁的变化在阿司匹林(AS)抗氧化损伤中的调控作用。方法:ELISA法检测不同浓度AS诱导Fn的表达,以及FeCl₃和去铁胺对AS诱导Fn表达的影响;同时使用RNA-proteinbandshiftassay及RT-PCR检测AS诱导铁蛋白表达过程中铁调节蛋白(IRP)结合活性及IRP₂mRNA水平的变化。结果:0.1mmol/L的AS可诱导内皮细胞Fn表达超过对照25%,随AS剂量的增大诱导Fn表达逐渐增加,二者间有明显的剂量依赖关系。AS诱导Fn表达后能明显增强细胞抗H₂O₂损伤的能力。但去铁胺+AS组细胞Fn表达明显降低,此时IRP的结合活性却为正常的3倍,IRP₂mRNA的表达水平也升高;而FeCl₃+AS组Fn表达明显高于去铁胺组,但IRP的结合活性降低、IRP₂mRNA表达水平下降。结论:阿司匹林通过下调IRP结合活性及IRP₂mRNA水平,导致细胞铁蛋白表达增加而发挥抗氧化损伤的作用。     

不同毒力结核分枝杆菌感染对巨噬细胞铁蛋白及铁转运蛋白表达的影响

目的探讨结核分枝杆菌国际标准强毒株H37Rv株(简称H37Rv株)和卡介苗菌株(简称BCG菌株)分别感染巨噬细胞后,各感染组巨噬细胞内铁蛋白(Fn)和铁转运蛋白(FPN)表达量及其时相性变化。方法分别用结核分枝杆菌H37Rv株和BCG菌株感染巨噬细胞RAW264.7细胞株,于感染后1、6、12、18、24 h,应用ELISA检测各组感染巨噬细胞培养上清液中Fn和FPN的含量;应用Western blot技术检测上述时间点各组感染巨噬细胞内Fn的表达量。结果不同菌株感染巨噬细胞后,巨噬细胞内Fn随处理时间延长表达逐渐增强;感染1 h,正常对照组Fn的表达高于H37Rv组和BCG组;感染6 h,感染组表达高于正常对照组,感染12 h,H37Rv组高于正常对照组,差异具有统计学意义(P<0.05);感染18 h和24 h,H37Rv组>BCG组>正常对照组,差异具有统计学意义(P<0.05)。FPN的表达量随时间变化逐渐降低。与正常对照组相比,H37Rv组、BCG组FPN的表达均呈现较低水平,为H37Rv组相似文献   

消化道癌症患者血浆纤维连接蛋白的变化及其与微血管的关系

分析27例消化道癌症患者(其中胃癌18例,食道癌与结肠癌9例)和6例胃溃疡病人的血浆纤维连接蛋白(Fn)的变化。结果发现三者间无明显差异(P>0.05),但胃癌病人中有转移病灶者(n=7)及伴胃炎者(n=10)与相应对照组比,血浆Fn有非常明显降低(p<0.01)。胃癌组织中Fn免疫荧光主要集中在胃癌病人胃壁组织多形核白细胞浸润的炎症区及微血管周围,癌变区Fn免疫荧光很弱,甚至消失。对上述变化的意义进行了讨论。     

外科手术前后患者血中肿瘤坏死因子等免疫学参数的观察

本文以TNF、CRP、Fn、EaRFC为指标,对25例胆囊炎等病人,在手术前后进行连续检测,结果提示术前患者血清TNF及经LPS和PHA诱导产生的TNFα和TNFβ含量均增高,而Fn量下降,CRP量升高,EaRFC百分率无异常,但其绝对值偏低。经手术治疗后,一周内对EaRFC及TNF含量影响不大,而绝大多数病人术后24h,CRP含量升高,Fn进一步降低,术后7天,CRP量恢复,Fn量升高。此外,还提示严重感染患者的血清TNF及经LPS和PHA诱生的TNFα和TNFβ含量与血WBC总数和PMN百分率升高相关。据此认为测定TNF、CRP、Fn有助于早期诊断感染和预测感染程度及判断疗效的指标。     

烧伤病人血浆纤维结合蛋白浓度的动态观察

纤维结合蛋白(Fibronectin)(简称Fn)对烧伤的临床重要性已引起国内外学者的注意。特别是Fn对单核巨噬细胞系统的调理控制作用,被认为是机体抗感染免疫的重要环节;而烧伤后ARDS(成人型呼吸困难综合证)的发生,认为与血浆Fn的耗竭关系甚大。对烧伤面积30％至85％的五名烧伤病人进行烧伤后血浆Fn浓度动态观察。对100名献血员血浆Fn浓度测定结     

建立ELISA法检测烧伤患者血清纤维连接蛋白活性

目的 :建立ELISA法检测烧伤患者血清纤维连接蛋白 (Fn)结合明胶活性并阐明其意义。方法 :采用明胶包被ELISA法 ,包被、封闭、加入待检血清、抗人Fn抗体、HRP SPA及TMB显色 ,测定 345例烧伤患者及 37例健康人血清Fn活性。结果 :该ELISA法敏感度高、特异性强、重复性好。检测烧伤患者血清发现Fn活性随着烧伤面积和深度的增加而降低 ,特重度烧伤患者Fn活性较健康人显著降低 (P <0 0 5 ) ,烧伤合并感染者血清Fn活性较未感染者降低。结论 :患者血清Fn活性下降与烧伤面积、深度和机体感染有关。测定Fn活性的ELISA方法学确立为阐明血清活性Fn在疾病中免疫生物学意义提供实验手段     

Modulation of polyclonal activation by plasma fibronectin and fibronectin fragments.

Modulation of activation of polyclonal IgM, IgG and IgM anti-DNA antibodies by plasma fibronectin (Fn) was studied because in some autoimmune diseases there appears to be a correlation between the increased level of Fn in the affected tissues and increased polyclonal B-cell activation. Fn caused a dose-dependent polyclonal activation of IgM, IgG and IgM anti-DNA antibody-secreting cells in cultures of mouse splenocytes. Fn significantly inhibited the generation of polyclonal antibodies by Fn-binding stimulants and did not significantly change the generation of polyclonal antibodies by the stimulants that do not bind Fn. Plasmin or trypsin digestion of Fn abolished both the polyclonal activating properties of Fn and the inhibitory effects of Fn that were selective for the Fn-binding polyclonal activators. Digestion of Fn with trypsin also generated immunosuppressive Fn fragments that inhibited polyclonal activation by both Fn-binding and non-binding bacteria. Under our culture conditions Fn or Fn digests were not mitogenic and had no effect on the mitogenicity of Fn-binding and non-binding stimulants. These results indicate that Fn can act as a polyclonal activator and that it can also modulate lymphocyte activation induced by other activators.     

大鼠低纤维连接蛋白血症时循环内皮细胞变化的研究

用静脉注射明胶的方法复制大鼠低纤维连接蛋白血症模型，结果发现，低Ｆｎ血症大鼠循环内皮细胞明显多于对照组，且与血浆Ｆｎ减少呈正相关。低Ｆｎ血症时，ＣＥＣ表面的Ｆｎ免疫荧光明显减弱，主动脉壁管腔面内皮Ｆｎ免疫荧光也明显减弱。作者提出，血浆Ｆｎ减少引起内皮细胞表面Ｆｎ减少，使内皮细胞间的链链作用和伸展作用削弱，从而引起ＣＥＣ在形态上的皱缩、折叠并成为ＣＥＣ增加的一个重要原因。     

失血性与内毒素性休克家兔血浆纤维连接蛋白含量的动态变化

在失血性与内毒性休克家兔中,利用免疫单扩和双扩法分别测定家兔休克前后不同时间血浆内Fn含量。结果表明,在失血性休克中,休克30分钟时,血浆内Fn有显著性下降,以后随着休克的发展,持续降低。休克30分钟时将血液回输.血压恢复,Fn含量也随之上升。在内毒素性休克中,休克30分钟时,与休克前比较,血浆Fn含量有显著性的升高,休克60分钟时,血浆Fn含量显著降低,后者60分钟变化与失血性休克相同。对上述变化可能发生机制进行了讨论。     

The effects of various drugs and immune complexes on the function of alveolar macrophages from patients with collagen-vascular diseases with interstitial pneumonia

Alveolar macrophages (AM) taken from sixteen patients with collagen-vascular diseases with interstitial pneumonia (CVD-IP+) were cultured with prednisolone (PSL), prostaglandin E2 (PGE2), colchicine (Colch), D-penicillamine or aggregated IgG (agg-IgG). The culture supernatants were tested on the fibroblast proliferation function and the amounts of fibronectin (Fn) and interleukin 1 (IL-1). The fibroblast proliferation was suppressed significantly by the supernatants of AM cultured with PGE2. The Fn production by AM was significantly suppressed by PGE2 and Colch. The IL-1 production by AM was not suppressed by these drugs, but was enhanced by Colch. In five patients with CVD-IP+, the fibroblast proliferation of AM supernatant was enhanced by agg-IgG. In these five patients, Fn and IL-1 production had a tendency to be increased by agg-IgG. The ratio of immune complexes (IC) in broncho alveolar lavage fluids to those in sera was significantly higher in patients with CVD-IP+ than in patients with CVD without IP suggesting a local production of IC in the lung in the patients with CVD-IP+.     

Evidence for a conformational change in human fibronectin which occurs between 4 and 37 degrees C

The effects of temperatures between 4 and 37 degrees C on the structure of human fibronectin (Fn) using monoclonal antibodies (MAb) with specificity for Fn have been studied. Three MAb bound to Fn in solution better at 4 than at 37 degrees C, assessed by both ELISA and immunoprecipitation. These MAb detected temp-dependent conformational changes in Fn which were not associated with a major refolding of the Fn molecule, since the S20,w of Fn and the binding of Fn to polyclonal anti-Fn were unchanged by temp shifts from 4 to 37 degrees C. Fn also was adhered directly to ELISA plates at 4 and at 37 degrees C, and then probed with MAb, with detergents, and with trypsin. One MAb bound better to surface adherent Fn when the Fn had bound to the surface at 4 rather than 37 degrees C. Both SDS and polyoxyethylene (20) sorbitan monolaurate (Tween-20) caused the release of more adherent Fn from surfaces to which it had adhered at 4 degrees C. Finally, trypsin released Fn fragments more rapidly and more completely from surfaces coated at 4 than at 37 degrees C. It is concluded that Fn has different conformations at 4 and 37 degrees C in solution and after adherence to surfaces, as reflected by MAb binding, detergent sensitivity and protease susceptibility. This conformational difference is not associated with alterations in the physiochemical properties of the molecule and is thus a result of a less extensive intramolecular rearrangement than the conformational changes resulting from manipulations of ionic strength or pH, and from binding to collagen or hydrophobic surfaces. Nonetheless, the more subtle conformational change demonstrated here may be important for the biological properties of Fn.     

Interaction of fimbriae of Haemophilus influenzae type B with heparin-binding extracellular matrix proteins

The interaction of the fimbriae of Haemophilus influenzae type b (Hib) with two heparin-binding extracellular matrix proteins, human fibronectin (Fn) and heparin-binding growth-associated molecule (HB-GAM) from mouse, were studied. The fimbriated Hib strain 770235 fim+, as well as the recombinant strain E. coli HB101(pMH140), which expressed Hib fimbriae, adhered strongly to Fn and HB-GAM immobilized on glass. Purified Hib fimbriae bound to Fn and HB-GAM, and within the Fn molecule, the binding was localized to the N-terminal 30,000-molecular-weight (30K) and 40K fragments, which contain heparin-binding domains I and II, respectively. Fimbrial binding to Fn, HB-GAM, and the 30K and the 40K fragments was inhibited by high concentrations of heparin. The results show that fimbriae of Hib interact with heparin-binding extracellular matrix proteins. The nonfimbriated Hib strain 770235 fim- exhibited a low level of adherence to Fn but did not react with HB-GAM, indicating that Hib strains also possess a fimbria-independent mechanism to interact with Fn.     

细胞因子调节对纤连蛋白在孕早期小鼠子宫内膜表达的研究

目的:通过研究细胞因子对FN表达的调节,探讨FN在围着床期子宫内膜表达的调节机理。方法:给孕早期小鼠注射不同的细胞因子,收集子宫内膜。分别用Immuno-blot法及RT-PCR法测定子宫内膜FN蛋白和nRNA的水平。结果:LIF低、高剂量组的FNmRNA和蛋白水平都比对照组高,统计分析差异有显著性（P<0.05,P<0.01）,IL-1和IL-1ra各组FN水平与对照组比无显著差异。结论:LIF在转录和转录后水平上调早期子宫内膜FN的表达,LIF参与着床与调节粘附分子的表达有关。IL-1系统则不影响子宫内膜FN的合成。     

Affinity of fibronectin for polyclonal IgG.

Fibronectin (Fn) is an adhesive glycoprotein that plays an important role in reticuloendothelial system functioning. Fn binds several macromolecules, it is found in cryoprecipitates obtained from patients with different diseases and it interacts in vitro with immune complexes. The interaction between Fn and polyclonal IgG was characterized by ligand affinity chromatography. After IgG was modified by attachment to a solid matrix or heat aggregation, it was able to interact with either soluble or immobilized Fn. The binding was highly influenced by ionic strength and pH. The estimated affinity constants were 3.0 x 10(6)/M when soluble Fn was applied to solid phase IgG and 2.3 x 10(7)/M when aggregated IgG interacted with immobilized Fn. The interaction may be relevant in situations in which immune complexes are involved.     

Recombinant interleukin-1 triggers the increase of circulating fibronectin level in rats

Interleukin-1 (IL-1) is one of the mediators responsible for the acute phase protein response during inflammation. We evaluated the effect of recombinant IL-1 alpha given intra-abdominally on rat circulating fibronectin (Fn) levels. Circulating Fn level, sampled between 3 h and 7 days after injection, was maximum at 24-48 h in Wistar rats treated with IL-1 at doses of 10 U and 100 U/100 g body weight (BW), respectively. Circulating Fn level in rats injected with 100 U/100 g BW IL-1 was higher than that of rats given 10 U/100 g BW IL-1. Circulating Fn level peaked at 24 h, whereas albumin levels decreased by 10% at this time. When frozen tissue sections of rat liver were examined using anti-Fn antibodies, the immuno stainings were denser in IL-1-treated animals than in controls. These findings suggest that IL-1 triggers plasma Fn production by the liver.     

Elevated expression of Fn14 in non-small cell lung cancer correlates with activated EGFR and promotes tumor cell migration and invasion

Lung cancer is the leading cause of cancer deaths worldwide; approximately 85% of these cancers are non-small cell lung cancer (NSCLC). Patients with NSCLC frequently have tumors harboring somatic mutations in the epidermal growth factor receptor (EGFR) gene that cause constitutive receptor activation. These patients have the best clinical response to EGFR tyrosine kinase inhibitors (TKIs). Herein, we show that fibroblast growth factor-inducible 14 (Fn14; TNFRSF12A) is frequently overexpressed in NSCLC tumors, and Fn14 levels correlate with p-EGFR expression. We also report that NSCLC cell lines that contain EGFR-activating mutations show high levels of Fn14 protein expression. EGFR TKI treatment of EGFR-mutant HCC827 cells decreased Fn14 protein levels, whereas EGF stimulation of EGFR wild-type A549 cells transiently increased Fn14 expression. Furthermore, Fn14 is highly expressed in EGFR-mutant H1975 cells that also contain an EGFR TKI-resistance mutation, and high TKI doses are necessary to reduce Fn14 levels. Constructs encoding EGFRs with activating mutations induced Fn14 expression when expressed in rat lung epithelial cells. We also report that short hairpin RNA-mediated Fn14 knockdown reduced NSCLC cell migration and invasion in vitro. Finally, Fn14 overexpression enhanced NSCLC cell migration and invasion in vitro and increased experimental lung metastases in vivo. Thus, Fn14 may be a novel therapeutic target for patients with NSCLC, in particular for those with EGFR-driven tumors who have either primary or acquired resistance to EGFR TKIs.