补体旁路激活致内皮细胞纤溶凝血相关分子表达变化及干预研究

目的研究补体旁路激活致微血管内皮细胞纤溶凝血相关分子表达的变化及干预。方法采用眼镜蛇毒因子激活血清补体旁路途径。将旁路活化的血清作用于人微血管内皮细胞,通过ELISA检测多个时间点细胞培养上清中Pselectin、VWF、t-PA、PAI-1、TF、TM的表达,采用NO试剂盒检测NO水平,并进一步研究吡咯烷二硫氨基甲酸(PDTC)、白藜芦醇对以上指标变化的影响。结果微血管内皮细胞经补体旁路活化产物刺激后,P-selectin、VWF的表达快速上调,其高峰时间为15 min,而纤溶功能分子t-PA、PAI-1也随后出现持续上调表达,与凝血功能相关的组织因子TF的表达水平持续上调,而血栓蛋白TM及NO的表达下降。PDTC、白藜芦醇对P-selectin、VWF、t-PA、PAI-1、TF上调表达具有抑制作用,对NO下调表达具有干预作用。而白藜芦醇能使TM的表达进一步下调。结论补体旁路活化产物会导致微血管内皮细胞纤溶凝血功能相关分子表达的变化,而PDTC、白藜芦醇对此种变化具有一定的影响。     

补体旁路激活导致内皮细胞活化和损伤

目的研究补体替代途径的激活对血管内皮细胞活化和损伤的作用。方法采用眼镜蛇毒因子(CVF)与人血清孵育,特异激活补体替代途径。将孵育物作用于人微血管内皮细胞,采用ELISA检测内皮细胞P-selectin、E-selectin、ICAM-1、MCP-1和IL-8的表达,采用酶活性测定法检测乳酸脱氢酶(LDH)活性,化学发光法检测内皮细胞caspase-8活化信号,MTT法检测内皮细胞增殖活性,并检测内皮细胞释放NO的变化。结果补体旁路激活导致内皮细胞瞬时表达P-selectin,并进而使内皮细胞上调表达E-selectin、ICAM-1、MCP-1和IL-8。内皮细胞经补体激活物刺激后,LDH释放增加、凋亡信号caspase-8活化上调以及NO释放下调,同时,细胞增殖也受到抑制。结论补体旁路激活能诱导内皮细胞活化和损伤,介导血管内皮的生理结构与功能发生变化,从而可能导致相应的炎症和组织损伤。     

补体旁路激活致内皮细胞纤溶凝血功能的改变及干预研究

目的研究补体旁路激活导致的微血管内皮细胞纤溶凝血功能的变化以及吡咯烷二硫氨基甲酸(PDTC)和白藜芦醇(Res)的干预作用。方法采用眼镜蛇毒因子激活血清补体旁路途径。将补体旁路活化的血清作用于人微血管内皮细胞(HMEC),检测多个时间点细胞培养上清的水解发色底物活性变化和对凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)的影响,并制备细胞悬液,检测细胞表面的抗凝血功能变化情况。采用PDTC、Res对上述变化指标进行干预研究。结果 HMEC经补体旁路活化产物刺激后,细胞培养上清的发色底物酶解活性明显上调;细胞培养上清导致正常血浆的APTT明显缩短,同时,对PT也有缩短的作用;经补体旁路活化产物刺激HMEC后制备的各时间点细胞悬液对正常血浆的APTT有明显的缩短作用,6 h刺激组的细胞悬液也表现出缩短PT的作用。PDTC和Res未能抑制发色水解活性的上调,但Res对APTT的缩短有明显的干预作用,而PDTC能在一定程度上抑制PT的缩短。结论补体旁路活化产物会导致HMEC纤溶凝血功能的失调,而PDTC和Res有一定的干预作用。     

脂多糖激活补体诱导内皮细胞释放黏附分子和凋亡

目的在细胞水平上研究脂多糖(lipopolysaccharide,LPS)激活血清补体对内皮细胞的作用和影响。方法研究LPS激活血清补体的作用方式和特点,观察LPS激活补体对内皮细胞表达黏附分子和凋亡的影响。采用ELISA检测内皮细胞释放P-selectin、E-selectin和ICAM-1的变化,化学发光法检测Caspase-3/7活化情况,SRB法检测LPS激活补体对内皮细胞生长的影响。结果 LPS能够激活血清补体,这种激活呈现量效、时效性。LPS激活血清补体可诱导内皮细胞瞬时明显释放P-selectin,E-selectin和ICAM-1表达也明显上调,同时可导致Caspase-3/7活化。在本实验条件下,LPS激活血清补体对内皮细胞生长未产生抑制。结论 LPS激活血清补体可损伤内皮细胞,导致内皮细胞明显表达黏附分子以及发生凋亡。     

绿原酸、咖啡酸和阿魏酸对补体旁路激活致内皮细胞炎症相关分子表达的干预

目的研究绿原酸及其代谢产物咖啡酸和阿魏酸对补体旁路激活导致人微血管内皮细胞炎症反应相关分子表达的干预作用。方法采用眼镜蛇毒因子激活人血清补体旁路,将补体旁路激活产物作用于人微血管内皮细胞,分别取不同时间点的细胞培养上清,采用ELISA方法检测ICAM-1、IL-6、IL-8、t-PA、PAI-1的含量;采用不同浓度的绿原酸、咖啡酸、阿魏酸预处理内皮细胞,然后将细胞暴露于补体旁路激活产物,检测不同时间点细胞培养上清中ICAM-1、IL-6、IL-8、t-PA、PAI-1的含量变化。结果补体旁路激活产物作用于人微血管内皮细胞后,引起ICAM-1、IL-6、IL-8、t-PA、PAI-1的表达上调。50、100、250μmol·L~(-1)的绿原酸、咖啡酸、阿魏酸对ICAM-1、IL-6、IL-8、t-PA、PAI-1的上调表达均有干预作用,其中对ICAM-1和IL-8的干预作用最明显。咖啡酸表现出最好的干预作用,其次为阿魏酸。结论一定浓度的绿原酸、咖啡酸、阿魏酸能有效抑制补体旁路激活引起的人微血管内皮细胞表达ICAM-1、IL-6、IL-8、t-PA、PAI-1的上调,提示绿原酸、咖啡酸、阿魏酸对微血管内皮细胞的炎症反应有一定的干预作用。     

补体旁路过度激活影响体内凝血功能

目的研究补体旁路的过度激活对体内纤溶、凝血及血小板的影响。方法采用尾静脉注射眼镜蛇毒因子(CVF)造成大鼠体内补体旁路的过度激活。检测大鼠给药前和给药后多个时间点血样的补体活性、t-PA、PAI-1、凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、凝血酶时间(TT)、纤维蛋白原(FIB)、P-selectin、PF-4、β-TG、血小板数量及聚集活性的变化,并检测小鼠静脉给予CVF后其尾部出血时间的变化。结果大鼠注射CVF后,血清补体活性在1h内基本消失。t-PA和PAI-1含量在1h内有明显增加,在48 h时间点t-PA/PAI-1比值有明显下降(P<0.01);PT、APTT、TT均略有变化,而血浆FIB含量明显下降;补体旁路的过度激活导致血中P-selectin、PF-4、β-TG明显上调,血小板数量明显减少,凝血酶和花生四烯酸诱导的血小板聚集被明显抑制,而ADP诱导的血小板聚集只受到轻微影响。小鼠尾部出血时间在1 h时明显缩短。结论补体旁路的过度激活能明显影响体内凝血功能,导致血液的高凝状态。     

三种化学小分子对补体旁路激活致内皮细胞黏附分子表达的干预及机制研究

目的研究白藜芦醇(Res)、PDTC和AG490 3种化学小分子对补体旁路激活致人微血管内皮细胞炎症反应相关黏附分子表达的干预作用和可能的作用机制。方法采用补体旁路激活产物作用于人微血管内皮细胞(HMEC)。TBA法检测细胞培养上清中丙二醛(MDA)的浓度,ELISA方法检测细胞培养上清中可溶性黏附分子ICAM-1、VCAM-1、E-selectin的表达,并采用多个浓度的Res、NF-κB信号通路抑制剂PDTC和JAK2信号通路抑制剂AG490预处理内皮细胞,研究3种抑制剂对细胞氧化水平和黏附分子表达的干预作用。利用Western blot检测补体旁路激活产物作用于内皮细胞对NF-κB p65磷酸化的影响及3种抑制剂的干预作用。结果 HMEC受补体旁路激活产物刺激后,导致细胞培养上清中MDA浓度升高,NF-κB p65磷酸化和黏附分子ICAM-1、VCAM-1和E-selectin的表达上调。Res可降低细胞培养上清中MDA的浓度。Res、PDTC和AG490能抑制NF-κB p65的磷酸化。Res与PDTC能抑制内皮细胞黏附分子ICAM-1和VCAM-1的表达,对E-selectin的表达有一定的抑制作用,而AG490能够明显抑制上述3种黏附分子的表达。结论 Res、PDTC和AG490对补体旁路激活产物致内皮细胞黏附分子表达上调有不同程度的抑制作用,其作用机制与NF-κB信号通路的活化有关,而JAK2可能是一个更重要的调控位点。     

砷对肝脏补体抑制活性的影响硒的拮抗效应

资料表明 ,砷可影响机体的免疫系统 ,引起机体免疫功能紊乱 ,在肿瘤发生发展中起重要作用[1～ 4 ] 。补体作为一重要的免疫因子 ,在肿瘤免疫中起着重要作用[5] 。补体的激活过程 ,受补体抑制因子等调节因素的调节。目前 ,国内外研究焦点多集中在砷对机体特异性细胞免疫和体液免疫功能的影响 ,而在砷对非特异性免疫的主要因子补体及其抑制因子影响方面研究很少 ,本研究用砷中毒模型研究砷对肝脏匀浆补体抑制水平的影响 ,旨在进一步阐明砷的毒作用机制 ,为砷中毒的防治提供依据。1　材料与方法1 1　主要试剂　三氧化二砷 (Ａｓ2 Ｏ3) ,分析纯 …     

柴胡粗提物对补体系统的抑制作用

目的研究柴胡粗提物对补体系统的作用。方法将柴胡粗提物分别与补体溶血实验中的各要素混合,作用一段时间后再加入其他组分,观测体系的溶血情况,探讨其对补体经典途径或旁路途径激活的作用。结果在经典激活途径中,柴胡粗提物与补体预先混合,能降低体系最终的溶血,而与溶血素或羊红细胞预先混合,体系的溶血无明显改变。在旁路激活途径中,柴胡粗提物与补体预先混合也能降低体系最终的溶血,而与兔红细胞预先混合,体系的溶血无明显改变。结论柴胡粗提物通过抑制补体,从而对溶血实验产生影响。     

他汀类药物改善脓毒症患者内皮细胞功能的机制研究进展

脓毒症是感染引起的失控的全身炎症反应综合征。脓毒症时全身炎症平衡紊乱可导致进行性的内皮细胞（EC）功能障碍,白细胞和血小板被激活,凝血纤溶破坏,最终导致多器官功能衰竭^[1]。EC功能障碍是脓毒症发展恶化的中心环节。脓毒症的发病率逐年上升,有资料显示^[2],脓毒症的病死率为25%～80%。近年来国外有研究证明他汀类药物治疗脓毒症能够降低其发病率及病死率,其主要机制之一可能与保护内皮细胞功能有关。现对他汀类药物保护脓毒症内皮细胞（EC）功能的机制作一综述。     

Section Review Biologicals & Immunologicals: Matrix metalloproteinases and malignant disease: Recent developments

One important proteolytic event during metastasis and angiogenesis appears to be the degradation of basement membrane components. A specific class of extracellular matrix (ECM) degrading metallo-enzymes, the matrix metalloproteinases (MMPs), also known as the matrixins, are thought to have a critical role in the creation of the proteolytic defect in basement membrane type IV collagen that allows tumour cells to escape from their primary site. The expression of matrixin proteases has been linked with many physiologic and pathologic processes involving ECM turnover. A number of correlative and functional studies suggest that the action of MMPs is required during tumour invasion and progression, as well as angiogenesis. The correlative studies have demonstrated overexpression of MMPs in many human cancer tissues at both the protein (immunoperoxidase) and mRNA (in situ hybridisation) levels. Functional studies have used endogenous inhibitors (Tissue Inhibitors of Metalloproteinases, TIMPs) or synthetic MMP inhibitors to block tumour cell invasion or metastasis formation. MMPs have also been implicated in the cell-surface proteolysis that modulates the adhesive behaviour of neoplastic cells. Therefore, targeting the activity of MMPs may provide a clinically useful mechanism for blocking local invasion and the metastatic spread of cancer cells. Results from a variety of studies indicate that mechanism-based inhibitors for MMPs can be developed and exploited in the clinical setting. This strategy has been utilised for the development of MMP inhibitors as substrate analogues have been modified to target selectively reactive moieties at the active site of MMPs.     

小鼠血清补体替代途径溶血活性测定的新方法

目的针对现有补体溶血活性测定方法不适宜测定小鼠血清补体的缺点,构建一种血清用量少、灵敏度高的小鼠血清补体替代途径溶血活性测定的新方法。方法选用具有代表性的3个小鼠品系KM、BALB/c和C57BL/6小鼠的血清补体作为测定材料,以兔红细胞为溶血靶细胞,利用眼镜蛇毒因子(CVF)特异激活补体替代途径的特点,构建和优化小鼠血清补体替代途径溶血活性测定的方法,并采用该方法测定两种抗补体蛋白对小鼠体内血清补体活性的影响。结果以CVF作为激活剂成功构建了测定小鼠血清补体替代途径溶血活性的微量新方法。3个品系小鼠的血清在5～20μl的范围内即可分别达到合适的溶血度。该方法明显减少了血清用量,并能有效提高溶血度。结论基于CVF特异激活补体替代途径的特点而构建的小鼠血清补体替代途径溶血活性测定新方法,血清用量少、灵敏度高、稳定性好,适用于测定小鼠血清补体的溶血活性。     

脑梗死患者血清补体水平改变的临床意义

目的探讨脑梗死患者病程中血清补体水平的变化及其临床意义。方法选取2010年1月—2010年12月在该院神内科治疗的脑梗死初发病例80例,根据患者病情分为急性期组(共40例)和恢复期组(共40例),比较两组患者的C3、C4水平。并选取40例健康对照进行对照分析。结果脑梗死患者急性期及恢复期的C3、C4补体水平较健康对照组显著升高(P0.01),急性期患者经治疗后,血清C3、C4补体水平下降,差异有显著性(P0.05),但急性期与恢复期血清C3、C4补体水平差异无显著性(P0.05)。结论补体C3、C4可能在脑梗死的发病过程中发挥重要作用。     

Development of a new pharmacophore model that discriminates active compstatin analogs

Compstatin and its active peptide analogs can potentially be used for therapeutic purposes because their binding to the third component of complement prohibits its conversion into the proteolytically activated form of the third component of complement, thus inhibiting complement cascades in all three complement pathways. Mallik and Morikis built three quasi-dynamic pharmacophore models for compstatin peptide analogs before, but only nine compstatin peptide analogs were incorporated in their study and the most active compstatin analog had only medium inhibitory activity. Since then, many more compstatin analogs have been synthesized and their inhibitory activities tested. Furthermore, the X-ray structure of AcCompNH2-V4W-H9A bound to the third component of complement has become available (PDB ID: 2QKI). In this paper, we utilized all the new information and built a new pharmacophore model using a distinct approach. Our model demonstrated good performance in a separate test set of 82 compstatin analogs: it accurately identified 70% of the analogs of medium or high inhibitory activities and misclassified only 8.5% of the analogs of low or no inhibitory activities. The results proved our pharmacophore model to be a filter of great sensitivity and specificity.     

土贝母皂甙A对实验动物免疫功能的影响

土贝母皂甙Aip2mg／kg对小鼠脾脏空斑形成细胞显著增高（P＜0．01），而po50mg／kg使小鼠脾脏空斑形成细胞下降（P＜0．01），po同剂量可使胸腺重量显著减轻（P＜0．01），使血清补体C3含量显著增高（P＜0．01），土贝母皂甙A和土贝母皂甙B对大鼠实验性变态反应性脊髓炎、特异性超敏反应有抑制作用。无论ip或po对小鼠血清溶血素生成、IgG含量及总补体活性均无明显影响。     

Factors in cobra venoms affecting the complement system

Three constituents of cobra venoms are known to interact with complement: the “cobra venom factor” (CVF), a high-molecular-weight factor (H-CoF), and the “cobra inhibitor” (CI). CVF and CI act by forming complexes with certain complement components. In doing so, CVF replaces an endogenous component, C3b, and hence activates the alternative pathway and leads to C3 (and C5) consumption. In contrast, CI competes with essential complex formations of endogenous components and thus inhibits various reactions. Both, CVF and CI, are useful tools to study the biochemistry of complement and its pathophysiological involvements. The effect of H-CoF on complement has not yet been studied in detail.     

Effect of boswellic acids on complement in adjuvant— and carrageenan—induced inflammation

Kapil A. Effect of boswellic acids on complement in adjuvant- and carrageenan-induced inflammation. Inflammopharmacology. 1994;2:361-367. The in-vivo effects of non-steroidal anti-inflammatory agents on the host immune system are still poorly understood. However, through inhibition of complement, boswellic acids (BA) exhibit adjuvant-induced and carrageenan-induced anti-inflammatory properties. The present work was aimed at evaluating the influence of BA on complement-related inflammation in the experimental models of inflammation. In adjuvant-induced arthritis and carrageenan-induced paw oedema in rats, BA were found to possess significant anti-inflammatory and complement-inhibitory activities. The intraperitoneal injection of BA (100 mg/kg twice a day), before and after FCA challenge and thereafter repeated for several days, significantly reduced foot pad thickness of experimental animal models and simultaneously also reduced complement activity. It also showed marked reduction in complement levels and inflammatory effects on carrageenan-induced paw oedema in rats when injected intraperitoneally (100 mg/kg twice a day).     

华支睾吸虫病患者血清中免疫球蛋白和C_3含量的变化

本文分别采用 ELISA 双抗体夹心法和琼脂单向免疫扩散法检测了华支睾吸虫病患者血清中各类免疫球蛋白和 C_3的含量。结果显示:患者血清中 I gG、I gM 和 I gE 的水平明显高于正常对照组,I gA 的水平与正常人相比无明显改变;而 C_3的含量显著低于正常人。提示:人体感染华支睾吸虫病后,I gG、I gM 和 I gE 与相应的特异性抗体呈同步增高的趋势;补体和抗体协同参与华支睾吸虫病的免疫学发病机理,在此过程中消耗补体,使 C_3含量降低。     

A new generation of potent complement inhibitors of the Compstatin family

Compstatin family peptides are potent inhibitors of the complement system and promising drug candidates against diseases involving under-regulated complement activation. Compstatin is a 13-residue cyclized peptide that inhibits cleavage of complement protein C3, preventing downstream complement activation. We present three new compstatin variants, characterized by tryptophan replacement at positions 1 and/or 13. Peptide design was based on physicochemical reasoning and was inspired by earlier work, which identified tryptophan substitutions at positions 1 and 13 in peptides with predicted C3c binding abilities [Bellows M.L., Fung H.K., Taylor M.S., Floudas C.A., López de Victoria A., Morikis D. (2010) Biophys J; 98: 2337-2346]. The new variants preserve distinct polar and nonpolar surfaces of compstatin, but have altered local interaction capabilities with C3. All three peptides exhibited potent C3 binding by surface plasmon resonance and potent complement inhibition by enzyme-linked immunosorbent assay. We also present enzyme-linked immunosorbent assay data and detailed surface plasmon resonance kinetic data of three peptides from previous computational design.