肾上腺髓质素拮抗转化生长因子β1的促纤维化作用及其机制

目的:探讨肾上腺髓质素(AM)在人肾小管上皮细胞系(HK-2)对转化生长因子β₁(TGFβ₁)促纤维化作用的影响及机制。方法:细胞总胶原的合成和分泌以[³H]-脯氨酸掺入量及培养液内[³H]-羟脯氨酸放射活性来判断;ELISA法检测培养液中纤维连接蛋白(FN)含量;FN、IV型胶原和组织型金属蛋白酶抑制剂-1(TIMP-1)mRNA的表达采用RT-PCR法;信号蛋白Smad2及Smad6蛋白表达采用Westernblot法。结果:(1)AM在蛋白和mRNA水平均明显抑制TGFβ₁刺激的胶原和纤维连结蛋白的表达;(2)AM抑制TGFβ₁刺激的TIMP-1mRNA的上调;(3)AM(10^-8mol/L)本身对Smad2和Smad6的表达无明显影响,且对TGFβ₁刺激的Smad2的表达也无明显影响;但是可以明显上调被TGFβ₁抑制的Smad6的表达。结论:在HK-2细胞,AM通过上调抑制性Smad6的表达拮抗TGFβ₁的促纤维化作用。     

补体C5b-9复合物刺激大鼠肾小球系膜细胞合成NO的机制探讨

目的:探讨人C5b-9复合物刺激大鼠肾小球系膜细胞(MC)合成一氧化氮(NO)的机制。方法:用人C5b-9复合物刺激培养的大鼠肾小球MC诱生肿瘤坏死因子α(TNFα)和白细胞介素1β(IL-1β),并用抗TNFα或抗IL-1β单克隆抗体进行处理。在上述基础上,分析处理3 h、6 h及24 h时与NO升高有关的某些指标的变化。结果:经C5b-9复合物刺激6、24 h后的MC(C5b-9组)产生TNFα明显高于对照组,并能被TNFα单抗逆转。用C5b-9复合物刺激MC未见IL-1β的产生。另用C5b-9刺激3 h时可见MC表达iNOS mRNA,而在刺激6 h和24 h时,MCiNOSmRNA表达,MC内cGMP含量及培养上清液中NO³_-/NO²_-含量均显著高于对照组。不过,C5b-9刺激时加用TNFα单抗处理,这些指标在6 h、24 h时均较C5b-9组低。结论:C5b-9复合物早期(3 h)能诱导MC表达iNOS mRNA,而6h后NO的升高则与MC释放的TNFα作用有关。     

抗胸腺细胞血清性肾炎模型大鼠肾小球中C5b-9的沉积及NO、TNFα含量分析

目的: 探讨抗胸腺细胞血清性肾炎(ATSN)大鼠肾小球内C5b-9复合物的沉积与某些炎症介质和细胞因子如:一氧化氮(NO)和肿瘤坏死因子α(TNFα)的含量情况。 方法: 大鼠一次性静脉注射抗胸腺细胞抗血清(ATS)建立ATSN模型,定期对ATSN大鼠肾小球中的补体C5b-9复合物进行免疫组化染色定位、显微图像扫描半定量分析;并对有C5b-9包绕的肾小球系膜细胞(MC)进行计数。测定ATSN大鼠肾中诱生型NO合酶(iNOS) mRNA的表达、尿液中NO的代谢产物(NO^-₂／NO^-₃)及TNFα的排泄量。 结果: ATSN模型大鼠肾小球MC先溶解坏死后继发增生,病变早期(溶解时相)补体C5b-9复合物主要定位于肾小球系膜区及MC表面;随着病程的进展,被C5b-9包绕的MC逐渐减少, 病程初期ATSN大鼠肾小球MC有明显的 iNOS mRNA表达, 尿液中NO^-₂／NO^-₃ 和TNFα的排泄量也明显增加。在ATSN病变的增生阶段(一般7 d后),上述指标的变化逐渐趋缓。 结论: ATSN模型大鼠肾小球中MC逐渐溶解与补体C5b-9沉积及NO和TNFα的合成与释放有一定关系。     

噻庚啶和山莨菪碱拮抗TNFα诱导的内皮细胞[Ca2+]i增高

目的：研究噻庚啶（Cyp）和山莨菪碱（Ani）对肿瘤坏死因子（TNFα）诱导单个内皮细胞内Ca²⁺浓度（[Ca²⁺]_i）变化的影响，以探TNFα介导休克和Cyp、Ani的抗休克的机制。方法：人脐静脉内皮细胞株（ECV304）接种于35 mm含2 mL DMEM培养基的组织培养盘中培养。Fluo-3/AM负载细胞，激光扫描共聚焦显微技术（LSCM）测定单个内皮细胞[Ca²⁺]_i。结果：TNFα使单个内皮细胞[Ca²⁺]_i呈剂量依赖性升高，在60 s内达到峰值，然后下降并保持在基础水平之上。共聚焦扫描图像显示细胞核区[Ca²⁺]_i升高比胞浆区明显，下降比胞浆区慢。Cyp（3×10^-5 mol/L或6×10^-5 mol/L）、Ani（2×10^-5 mol/L或4×10^-5 mol/L）均能显著抑制由TNFα（1.2×10^-9 mol/L）诱导的单个内皮细胞[Ca²⁺]_i升高。结论：TNFα诱导内皮细胞[Ca²⁺]_i升高可能是TNFα介导休克的重要机制；Cyp和Ani抑制TNFα诱导的[Ca²⁺]_i升高可能是其抗休克作用的机制之一。     

恶性血液病细胞WT1基因表达及其临床预后相关性研究

近年来不少学者发现 WT1基因在白血病中存在高表达 [1 - 3 ] ,但其作用机理尚不清楚 ,与白血病的预后关系也有争论[4,5 ] 。我们用逆转录多聚酶链反应 (RT- PCR)检测了多种白血病细胞系和淋巴瘤细胞 ,以及 15 2例造血系统恶性疾病患者WT1m RNA表达情况 ,探讨其临床意义。1　研究对象与方法1.1　细胞系　 K5 6 2 (慢性粒细胞白血病急性红白血病变 )、HL- 6 0 (急性髓系白血病 )、HEL(急性红白血病 )、DAMI(急性巨核细胞白血病 )、H9(T细胞淋巴瘤 )及 U937(组织细胞型淋巴瘤 )。1.2　病例组　收集本院 1995～ 1998年住院的造血系统…     

p21wafl在1, 25(OH)2D3调节人骨肉瘤细胞系HOS-8603增殖分化中的作用

目的:探讨p21^wafl在1, 25(OH)₂D₃调节人骨肉瘤细胞系HOS-8603增殖中的作用。方法: 用定量RT-PCR法检测1, 25(OH)₂D₃对p21^waflmRNA表达的诱导作用, 并构建稳定表达p21^wafl真核表达载体的细胞系HOS-p21^wafl进一步观察该细胞的生长及分化情况。结果:1, 25(OH)₂D₃作用2h即可诱导HOS-8603细胞内源性p21^wafl的表达, 4h达高峰, 24h仍未回降。细胞过度表达p21^wafl后生长速度明显减慢, 培养6d时细胞数为未转染细胞的50%;并且组织化学染色结果表明细胞的分化标志性抗原碱性磷酸酶(AKP)的表达明显增强。结论:表明1, 25(OH)₂D₃对p21^waflmRNA诱导作用可能是激素调节细胞增殖分化的重要机制之一。     

TNFα和IL-10在巨细胞病毒感染人胚肺成纤维细胞中的作用

目的:研究TNFα和IL-10对人巨细胞病毒(HCMV)感染人胚肺成纤维细胞(HEL)的影响,以及感染细胞产生TNFα的变化,探讨有关细胞因子在HCMV感染免疫中的作用。方法:用不同浓度的TNFα和IL-10作用于HEL,24h后感染病毒,研究TNFα和IL-10对HCMV感染HEL的影响。用HCMV感染HEL,感染后(4、24、48、72、96h)分别收集培养上清液,用ELISA法检测TNFα含量。结果:在病毒感染前,中、高浓度TNFα或低、中浓度IL-10可抑制HCMV在HEL内的增殖。HCMV感染HEL后,细胞产生TNFα的量无明显改变。结论:TNFα和IL-10在HCMV感染免疫过程中起作用。     

血管紧张素II及其受体在血管平滑肌细胞迁移中的作用

目的:探讨血管紧张素II(AngII)及其受体(ATRs)在局部血管损伤后血管平滑肌细胞(VSMC)迁移中的作用及其机制。方法:以体外培养VSMC为基础,采用细胞化学和改良Boyden'schamber的方法,观察AngⅡ干预VSMC后AngII受体的表达、VSMC迁移能力的变化、肌动蛋白纤维丝的动态组装变化,并探讨AT₁R拮抗剂、AT₂R拮抗剂对上述观测指标的影响。结果:AngII10^-7mol/L可以刺激VSMC发生迁移,该作用是通过影响VSMC内应力纤维动态组装而实现的;AngII干预VSMC后可使AT₁R表达上调,随着作用时间延长AT₁R表达水平下降。AT₁R拮抗剂可下调AT₁R表达。AngII通过AT₁R的介导发挥其影响VSMC迁移能力的生物学效应。AT₂R对此无明显影响。结论:AngII通过AT₁R介导来调节VSMC内肌动蛋白微丝的动态组装,进而改变VSMC的迁移能力,从而发挥其介导VSMC迁移的生物学效应。     

2型糖尿病患者血清转化生长因子β1水平的改变

目的:探讨2型糖尿病(DM)患者血清TGFβ₁变化。方法:45例2型糖尿病患者根据尿白蛋白排泄率(UAER)分为正常蛋白尿组(NA)、微量蛋白尿组(MA)、临床蛋白尿组(ODN)。分别检测各组的血清TGFβ₁、空腹血糖(FBG)、血脂、糖化血红蛋白(HbA_1c)及肾功能(BUN、Cr、Ccr)。结果:3组糖尿病与正常对照组比较血清TGFβ₁有显著性差异,ODN与MA、NA比较也有显著性差异。相关分析表明血清TGFβ₁与低密度脂蛋白(LDL)、Cr、HbA_1c、UAER呈正相关。结论:2型糖尿病患者血清TGFβ₁明显增高,且和糖化血红蛋白、肾功能损害呈明显正相关。     

慢性心力衰竭大鼠内皮素系统表达的变化

目的:研究慢性心衰大鼠在心衰早期(冠脉结扎10d)和心衰晚期(冠脉结扎70d)的左心室内皮素受体A(ET_AR)和内皮素受体B(ET_BR)及内皮素前体(PreproET₁)的mRNA表达水平,了解心衰时心肌内皮素系统的变化及其与病程的关系。方法:用逆转录-聚合酶链反应(RT-PCR)检测冠脉结扎心衰模型大鼠的左心室ET_A和ET_B受体及PreproET₁的mRNA表达,以放射免疫技术检测血浆中内皮素(ET₁)和心钠素(ANP)的浓度。结果:冠脉结扎10d后,血浆ET₁、ANP的水平和左心室ET_AR、ET_BR、PreproET₁的mRNA表达水平均明显高于假手术组;冠脉结扎70d后,血浆ET₁和ANP的水平显著高于冠脉结扎10d组和假手术组,ET_A受体mRNA表达水平和假手术组相比无显著性差异,而ET_B受体及PreproET₁mRNA表达水平仍明显高于假手术组,但显著低于冠脉结扎10d组。结论:在慢性心衰的不同阶段,左心室内皮素系统的改变参与机体心脏功能的调节,循环ET₁水平的上升在早期主要是由于PreproET₁的mRNA表达上调所致,在后期则主要与下调的内皮素受体水平有关。     

Expression of cytokines and their receptors by human thymocytes and thymic stromal cells.

The repertoire of cytokine and cytokine receptor mRNA expressed by unstimulated human thymocytes and thymic stromal cells was explored by a quantitative polymerase chain reaction (PCR) using sequence specific internal standards. Of the 18 cytokines tested we found a considerable overlap in the expression of cytokines by human thymocytes and by thymic stromal cells; both cell types express the mRNA for interleukin-1 beta(IL-1, IL-6, IL-7 and tumour necrosis factor-alpha (TNF-alpha). However, there are substantial differences in the levels of cytokine mRNA expressed in these two types of cells as revealed by the quantitative PCR assay. Stromal cells express considerably higher levels of IL-1 beta and IL-6 than thymocytes (14- and 27-fold respectively). In addition, a number of cytokines such as lymphotoxin and interferon-gamma (IFN-gamma), are expressed exclusively in thymocytes whereas others such as stem cell factor (SCF), IL-1 receptor antagonist-2 (IRAP-2) and granulocyte-macrophage colony-stimulating factor (GM-CSF) are produced only in stromal cells. There is a complete overlap in the expression of a group of cytokine receptors tested in thymocytes and thymic stromal cells; these include IL-1R, IL-2R, IL-6R, IL-7R, TNFR and stem cell growth factor receptor (c-KIT). The expression of specific cytokines by thymic stromal cells and the parallel expression of their receptors on thymocytes under physiological conditions, support the hypothesis that these cytokines participate in paracrine interactions between these two cell populations during thymocyte differentiation.     

Identification of differentiation-inducing activity produced by human bone marrow stromal cell line LP101

We have previously reported that human promyelocytic leukemia HL-60 cells can be induced to differentiate into mature granulocytes when HL-60 co-cultivated with human bone marrow stromal LP101 cells. In the present study, we investigated which factors produced by LP101 cells induce HL-60 cells to differentiate into mature granulocytes. The expression of the cell surface antigen CD11b on HL-60 cells was increased after a 72-h culture with the conditioned medium (CM) obtained from LP101 cells. LP101 cells were observed to produce various cytokines, including TNF-alpha, GM-CSF and IL-6. The neutralizing antibodies against these cytokines partially suppressed the CM-induced differentiation of HL-60 cells. Recombinant TNF-alpha induced the differentiation of HL-60 cells, and GM-CSF and IL-6 additionally enhanced the effect of TNF-alpha. When the CM was divided into a low molecular weight (LMW) fraction and a high molecular weight (HMW) fraction by ultrafiltration, the LMW fraction synergistically enhanced the differentiation inducible activity of TNF-alpha. These results demonstrate that LP101 cells induce the differentiation of HL-60 cells by producing various cytokines including TNF-alpha, IL-6, and GM-CSF, and that unknown low molecular weight factors also participate.     

The effect of cytokines on the expression and function of Fc receptors for IgG on human myeloid cells

We examined expression and cytotoxic triggering capability of the three Fc receptors for IgG (Fc gamma R) on human monocytes, PMNs and myeloid cell lines after in vitro culture with various cytokines. Fc gamma R expression was evaluated using specific anti-Fc gamma R monoclonal antibodies (mAb). The cytotoxic capability of each Fc gamma R was examined after the effector cells were treated with the recombinant cytokines IFN-gamma. TNF alpha, GM-CSF, G-CSF, M-CSF, IL-1, IL-2, IL-3, IL-4, or IL-6. Hybridoma cell lines (HC) bearing antibody directed to Fc gamma RI (HC 32), Fc gamma RII (HC IV.3) or Fc gamma RIII (HC 3G8) were used as targets, as were chicken erythrocytes (CE) sensitized with heteroantibodies composed of anti-Fc gamma R mAbs (32, IV.3, 3G8) linked to anti-CE antibody. Only IFN-gamma treatment significantly increased Fc gamma R expression and then only Fc gamma RI. IFN-gamma dramatically up-regulated Fc gamma RI expression on all cells tested. However, ADCC was enhanced by treatment with a number of cytokines other than IFN-gamma. GM-CSF, TNF, and IFN-gamma treatment enhanced killing of HC 32 and HC IV.3 by in vitro cultured monocytes. G-CSF treatment enabled PMNs to kill HC through Fc gamma RII, whereas PMN killing of HC through Fc gamma RIII could not be induced by any of the cytokines studied. Although only IFN-gamma treatment increased ADCC of CE by monocytes, GM-CSF treatment as well as IFN-gamma treatment augmented ADCC of CE by PMNs. In addition to IFN-gamma treatment, IL-6 treatment enabled U937 cells to lyse CE. Whereas IFN-gamma-treated U937 cells killed CE through both Fc gamma RI and Fc gamma RII, IL-6-treated U937 cells killed CE only through Fc gamma RI. In addition to IFN-gamma treatment, G-CSF treatment enabled HL-60 cells to lyse CE through both Fc gamma RI and Fc gamma RII. These results demonstrate that although IFN-gamma appears unique in regulating Fc gamma R expression on myeloid cells, cytokines other than IFN-gamma affect ADCC by these cells in a receptor-specific manner.     

G-CSF and GM-CSF concentrations and receptor expression in peripheral blood leukemic cells from patients with chronic myelogenous leukemia

Granulocyte-colony stimulating factor (G-CSF) and granulocyte-macrophage-CSF (GM-CSF) are the principal cytokines in granulopoiesis and differentiation of granulocytic precursors. Their physiologic effects are mediated by binding to specific cell surface receptors (G-CSFr and GM-CSFr, respectively), which are widely expressed from immature bone marrow cells to mature peripheral granulocytes. The fact that concentrations of plasma G-CSF and GM-CSF and their receptors are changed in infectious diseases showing neutrophilia is known, but such changes in patients with chronic myelogenous leukemia (CML) have not been studied. Based on quantitative assays of plasma G-CSF and GM-CSF and their receptors on the peripheral granulocytes of CML patients and healthy controls, this study analyzes the differences between these groups in G-CSF and GM-CSF levels, as well as quantitative and qualitative changes in the receptors. Plasma levels of G-CSF and GM-CSF were measured in 47 patients in the chronic phase of CML and 25 healthy adults as normal controls. G-CSFr and GM-CSFr on peripheral granulocytes were analyzed by quantitative flow cytometry, and changes in G-CSF and GM-CSF receptor counts were also measured. Plasma concentrations of G-CSF and GM-CSF in CML patients were similar to normal controls (p>0.05). The quantity of G-CSFr on neutrophils was more highly expressed than on other cell types in both groups, and the amount of this receptor in patients with CML was less than in normal controls (p=0.001). GM-CSFr was expressed in higher concentrations on monocytes than neutrophils, and there was no difference in the amount of GM-CSFr on neutrophils. After incubation with excess G-CSF, the expressed amounts of G-CSFr on neutrophils and monocytes were decreased in both groups. However, G-CSFr on the monocytes was decreased in healthy controls (p=0.02) with no difference in patients with CML. The quantities of GM-CSFr expression on neutrophils and monocytes after incubation with excess GM-CSF were decreased in both groups. Granulocyte counts in peripheral blood of CML patients were not correlated with the plasma concentrations of G-CSF or GM-CSF, nor with the expression of G-CSFr or GM-CSFr on granulocytes. Granulopoiesis in patients with CML was not mediated by increased plasma CSF concentrations, and there was no difference in the amounts of G-CSFr or GM-CSFr expressed on the granulocytes. This suggests that a structural change may occur on monocytes of CML patients, since the binding capacity of G-CSFr to G-CSF on the monocytes is different from the normal controls.     

Spatiotemporal distribution of gp130 cytokines and their receptors after status epilepticus: comparison with neuronal degeneration and microglial activation

Although numerous studies have demonstrated the neurotrophic capacity of gp130 cytokines, it remains unclear whether endogenously expressed cytokines actually function in a direct neuromodulatory manner. Therefore, using the lithium-pilocarpine status epilepticus model, we performed a detailed in situ hybridization time-course study of five gp130 cytokines (interleukin [IL]-6, leukemia inhibitory factor [LIF], IL-11, oncostatin-m [OSM], and ciliary neurotrophic factor), gp130, and the receptors of the cytokines we found to be induced (IL-6 receptor [IL-6R], LIF receptor [LIF-R], and IL-11 receptor [IL-11R]). Additionally, to further understand the regulation of these cytokines, we compared their expression with the pattern of neuronal degeneration and microglial activation. Under control conditions, all cytokines, except LIF, exhibited faint to moderate expression in hippocampal principal layers. After seizure, IL-6, LIF, and IL-11 exhibited a rapid, robust, and transient upregulation in non-principal cells. LIF also exhibited a remarkably early and transient induction in the granule cell layer of the dentate gyrus. OSM exhibited only a mild and inconsistent induction. All receptors examined were strongly expressed only in hippocampal principal layers under control conditions. A mild and late induction of the IL-6R, LIF-R, and IL-11R occurred after seizure with a scattered distribution. A progressive and chronic induction of gp130 was observed in cells that appeared to be associated with blood vessels. Degeneration of hilar interneurons and CA1 pyramidal cells was early and progressive. Granule neurons of the dentate gyrus, however, exhibited a delayed and precipitous pattern of degeneration, specifically in the lateral portion of the superior blade. Microglial activation was maximal 24-48 h post-seizure. We speculate that gp130 cytokines play a paracrine, neuromodulatory role in the hippocampus since both before and after seizure, principal cells appear to be the major cell type expressing the receptors for these cytokines. Furthermore, we suggest that activity-dependent mechanisms may be involved in the regulation of cytokines expressed early, and that relatively late occurring cytokine expression may be elicited by injury-related stimuli.     

Differential regulation of interleukin-6 receptors by interleukin-6 and interferons in multiple myeloma cell lines

Interleukin-6 (IL-6) mediates pleiotropic functions through specific receptors (IL-6R) composed of an 80-kDa binding protein, associated with a non-ligand binding protein (gp130) which transduces the signal. Because IL-6 is the major tumor growth factor in multiple myeloma, we investigated the regulation of IL-6R in two human multiple myeloma cell lines. Binding experiments with ¹²⁵I-labeled IL-6 showed that IL-6R were expressed at a high density on RPMI-8226 cells (15 000 receptors/cell), but no specific binding was detected on XG-1 cells, whose growth depends on the presence of exogenous IL-6. However, when IL-6 was removed from the culture medium, high-affinity IL-6R appeared on the surface of XG-1 cells (5300 sites/cell). Treatment of RPMI-8226 cells with IL-6 reduced the number of IL-6R without changing their affinity. This reduction was dose dependent and was not affected by acid treatment which dissociates ligand-receptor complexes. Cross-linking experiments showed that the formation of one IL-6/receptor complex of 160 kDa markedly decreased upon IL-6 treatment, while the other complex of 190 kDa became undetectable. These data provide evidence for ligand-induced down-regulation of membrane IL-6R expression in myeloma cells. Treatment of RPMI-8226 cells with interferon-α (IFN-α), which inhibits the growth of these cells, stimulated IL-6R expression and increased the formation of the 160-kDa IL-6/receptor complex. This stimulation was specific for IFN-α, since IFN-γ reduced the number of IL-6R. These data indicate that, in myeloma cells, IL-6R are differentially regulated by IL-6 and IFN-α.     

Secretion of the eosinophil-active cytokines interleukin-5, granulocyte/macrophage colonystimulating factor and interleukin-3 by bronchoalveolar lavage CD4+ and CD8+ T cell lines in atopics asthmatics,and atopic and nonatopic controls

Specific eosinophil accumulation and activation within the asthmatic bronchial mucosa are thought to occur at least partly through the actions of cytokines, including interleukin (IL)-5, IL-3 and granulocyte/macrophage colonystimulating factor (GM-CSF). Although mRNA encoding some of these cytokines has been demonstrated in bronchoalveolar lavage (BAL) fluid cells and bronchial biopsies from asthmatics, it has yet to be established whether these cells produce the translated products and whether expression is associated with CD4⁺ T helper or CD8⁺ cytotoxic T cells. We addressed this problem by raising polyclonal CD4⁺ and CD8⁺ T cell lines from the BAL fluid of six atopic asthmatics, five atopic non-asthmatics and seven non-atopic non-asthmatic controls. BAL fluid cells obtained at fiberoptic bronchoscopy were depleted of adherent cells, and then T lymphocytes expanded by stimulation with monoclonal anti-CD3 antibody and recombinant human IL-2. When lymphocytes had expanded to sufficient numbers, CD4⁺ and CD8⁺ cells were separated by positive selection with magnetic beads coated with anti-CD4 or anti-CD8 monoclonal antibodies and further expanded. Cytokine secretion by standardized cell numbers was measured by enzyme-linked immunosorbent assays. BAL CD4⁺ T cell lines from the asthmatics secreted significantly elevated quantities of both IL-5 and GM-CSF as compared with lines from the atopic and non-atopic controls (p = 0.023–0.003). In contrast, IL-3 secretion did not significantly differ between the groups. In some subjects, CD8⁺ T cell lines also secreted significant quantities of these cytokines and there was a trend for IL-5 secretion by these cells to be higher in asthmatics than non-atopic controls (p = 0.035). These data are consistent with the hypothesis that activated T lymphocytes from asthmatics, particularly of the CD4⁺ subset, are predisposed to release elevated quantities of cytokines relevant to the accumulation and activation of eosinophils.     

纤维连接蛋白对内毒素血症小鼠保护作用的实验研究

目的:研究纤维连接蛋白对内毒素血症小鼠的保护作用及其意义。方法:采用明胶亲和层析从正常人血浆纯化纤维连接蛋白, 观察纤维连接蛋白处理的半乳糖胺敏化内毒素小鼠的生存率, 用病理组织学、电镜观察超微结构、DNA片段化分析、RT-PCR检测小鼠肝脏损害及TNFα、IL-1β、IL-6mRNA表达水平。结果:①纤维连接蛋白处理的半乳糖胺敏化内毒素小鼠的死亡率明显低于对照组。②病理组织学表明半乳糖胺敏化内毒素小鼠肝脏发生广泛变性坏死, 而治疗组小鼠肝脏发生轻微变性坏死。③电镜观察半乳糖胺敏化内毒素小鼠肝脏发现多数肝细胞呈凋亡性改变, 而纤维连接蛋白治疗组小鼠多数肝细胞大小形态结构正常, 未见凋亡细胞。④DNA片段化分析半乳糖胺敏化内毒素小鼠肝脏细胞DNA呈现凋亡特征性梯状条带。而纤维连接蛋白治疗组则无。⑤RT-PCR研究发现纤维连接蛋白治疗组小鼠肝脏TNFα、IL-1β、IL-6mRNA的表达水平低于对照组。结论:纤维连接蛋白可能通过降低半乳糖胺敏化内毒素小鼠肝脏TNF-α、IL-1β、IL-6的过度表达而起保护作用, 其将成为防止败血症肝功能衰竭的方法之一。