综述与专论：蛋白质错误折叠相关疾病的多肽药物研究进展

蛋白质和多肽发生错误折叠形成不可溶的淀粉样纤维的过程,与阿尔茨海默病、帕金森病等多种神经退行性疾病密切相关。这些疾病可导致认知能力下降以及运动缺陷等症状。虽然已有多种相关治疗方案处于临床试验中,但目前仍无明确有效的方法可治愈或长期减缓疾病的进展。探寻和研究抑制淀粉样聚集、识别并促进毒性聚集物清除的抑制剂分子是药物研发的重要策略之一。在不同类型的抑制剂中,多肽类抑制剂因具有高特异性、低毒性、多样性,以及修饰后的抗水解稳定性和血脑屏障通透性,有望成为候选药物分子。本文总结了针对阿尔茨海默病相关的Aβ和Tau蛋白以及帕金森病相关的α-synuclein蛋白淀粉样纤维化的多肽抑制剂研究进展。基于淀粉样纤维化核心序列及纤维核心结构进行合理设计,或通过随机筛选,均可获得多肽抑制剂。这些天然和非天然的多肽分子大多具有抑制淀粉样纤维化、解聚成熟纤维和降低细胞毒性的作用,其中一些多肽在退行性疾病动物模型实验中,显示出降低脑损伤和缓解认知及运动障碍的效果。这些研究揭示了多肽作为蛋白质错误折叠和聚集相关疾病药物的特点,为研发一类新的有效药物奠定了基础。     

蛋白质错误折叠相关疾病的多肽药物研究进展

蛋白质和多肽发生错误折叠形成不可溶的淀粉样纤维的过程,与阿尔茨海默病、帕金森病等多种神经退行性疾病密切相关。这些疾病可导致认知能力下降以及运动缺陷等症状。虽然已有多种相关治疗方案处于临床试验中,但目前仍无明确有效的方法可治愈或长期减缓疾病的进展。探寻和研究抑制淀粉样聚集、识别并促进毒性聚集物清除的抑制剂分子是药物研发的重要策略之一。在不同类型的抑制剂中,多肽类抑制剂因具有高特异性、低毒性、多样性,以及修饰后的抗水解稳定性和血脑屏障通透性,有望成为候选药物分子。本文总结了针对阿尔茨海默病相关的Aβ和Tau蛋白以及帕金森病相关的α-synuclein蛋白淀粉样纤维化的多肽抑制剂研究进展。基于淀粉样纤维化核心序列及纤维核心结构进行合理设计,或通过随机筛选,均可获得多肽抑制剂。这些天然和非天然的多肽分子大多具有抑制淀粉样纤维化、解聚成熟纤维和降低细胞毒性的作用,其中一些多肽在退行性疾病动物模型实验中,显示出降低脑损伤和缓解认知及运动障碍的效果。这些研究揭示了多肽作为蛋白质错误折叠和聚集相关疾病药物的特点,为研发一类新的有效药物奠定了基础。     

黑龙江省抗纤维化生物治疗重点实验室

黑龙江省抗纤维化生物治疗重点实验室隶属于牡丹江医学院．建立于2000年．是黑龙江省“十五”期间首批普通高校重点建设实验室,2006年10月．经黑龙江省教育厅验收成为黑龙江省普通高校组织损伤与修复重点实验室。2007年12月,经黑龙江省科技厅批准为黑龙江省抗纤维化生物治疗重点实验室。重点实验室以建设组织损伤与修复、抗纤维化生物治疗平台为重点．构建基础医学、分子生物学、细胞生物学、药学相结合的新科研平台。     

脂氧素——抗组织纤维化的新药物

组织纤维化是器官组织内纤维结缔组织增多而实质细胞减少的一类疾病,组织损伤导致的慢性炎症反应是纤维化形成的根本原因. 脂氧素是体内重要的内源性促炎症消退介质,兼具抗炎和促炎症消退双重作用,对多种炎症细胞和炎症相关基因有显著的负性调节作用,为炎症反应的重要“刹车信号”. 脂氧素可以促进炎症及时消退而防止其蔓延为慢性炎症,因此,它极有可能在抑制纤维化的形成中起到至关重要的作用.近年来,随着对脂氧素研究的不断深入,其抗纤维化作用日益凸显,成为极有价值的抗纤维化潜在药物.     

多肽淀粉样沉积形成机制研究进展

淀粉样肽(amyloid peptide)是一类在一定条件下易于形成沉积的多肽或者蛋白质。这类多肽或者蛋白在一定的组织部位沉积引起的细胞毒性和细胞凋亡被认为是一些疾病的主要原因。尽管这类多肽在一级结构上没有明显的同源性,但它们形成的沉积具有共同的结构特征,即这些多肽形成了具有β片层结构的纤维状聚集体。淀粉样沉积的形成机制尚不清楚。研究认为,在沉积过程中,多肽分子首先形成寡聚体,然后转变为规则的β折叠结构,进而组装形成淀粉样纤维。很多因素有助于这一转变,如多肽序列、氨基酸残基间的相互作用,介质的疏水性、温度、pH以及金属离子的浓度等。对多肽淀粉样沉积形成机制的深入研究将为探索相关疾病病因和开发治疗药物提供极有价值的依据。     

抗肝纤维化药物的研究进展

肝纤维化(Iiver fibrosis)是细胞外基质(ECM)合成和降解不平衡的结果,是各种慢性肝病向肝硬化发展所共有的病理改变和必经途径.LF的致病因子包括病毒、酒精、药物等,其中乙肝病毒引起的病毒性肝炎是我国最普遍的肝病之一,因此开发抗肝纤维化药物将有利于我国肝病的治疗,本文主要介绍了抗肝纤维化药物的研究进展.     

抗胰腺星状细胞药物研究进展

慢性胰腺炎传统治疗方法效果不确定,需要寻找新型有效药物。活化的胰腺星状细胞在胰腺纤维化过程中起了重要的作用,使之成为新的治疗靶点。活化PSC的物质分为三类,即炎症介质、氧化应激和毒素。本文就近年来针对以上不同活化PSC的介质和相关通路的抗星状细胞药物进行综述。     

胰腺星状细胞的调控及转归

活化的胰腺星状细胞(pancreatic stellate cells,PSCs)是胰腺炎致胰腺纤维化的主要效应细胞。近年来,学者普遍认为,胰腺纤维化早期阶段是动态可逆的,因此,若在胰腺损伤的早期阶段,抑制PSCs的增殖、迁移,减少损伤部位PSCs的数目,降低细胞外基质(extracellular matrix,ECM)的生成,将可能逆转胰腺纤维化。该文以PSCs为靶点阐述了抗胰腺纤维化的新策略。     

SIRT3在纤维化疾病中的研究进展

纤维化是大多数慢性炎症性疾病的病理特征,临床中较常见的包括肝纤维化、肾纤维化、心肌纤维化和肺纤维化等。持续发展的纤维化可破坏组织正常结构并影响其功能,甚至引起器官衰竭和死亡,目前尚无有效治疗策略。沉默信息调节因子3 (sirtuin3, SIRT3)是一种线粒体去乙酰化酶,已被证明参与线粒体代谢和体内平衡的多个方面,保护线粒体免受各种损伤。近年来相关研究发现,SIRT3在心脏、肝、肾、肺等多种器官纤维化中均有不同程度的表达,通过调节线粒体代谢、细胞凋亡、自噬等生物过程,参与纤维化的发生发展。本文就SIRT3在纤维化疾病中的调控作用进行综述。     

肝纤维化动物模型造模方法的研究进展

肝纤维化是肝脏受到损伤后细胞外基质合成、降解与沉积不平衡的一种修复反应。对肝纤维化进行早期诊断、早期治疗,预防肝硬化的发生、发展,对肝病患者的生命质量具有重要的意义。而肝纤维化动物模型的建立,既可深入全面地研究肝纤维化发病机制,又可为临床筛选防治肝纤维化药物提供基础研究。通过对常用的肝纤维化动物模型造模方法的阐述,为肝纤维化的基础实验研究和临床治疗提供参考。     

Three's company: two or more unrelated receptors pair with the same ligand

Intercellular communication relies on signal transduction mediated by extracellular ligands and their receptors. Although the ligand-receptor interaction is usually a two-player event, there are selective examples of one polypeptide ligand interacting with more than one phylogenetically unrelated receptor. Likewise, a few receptors interact with more than one polypeptide ligand, and sometimes with more than one coreceptor, likely through an interlocking of unique protein domains. Phylogenetic analyses suggest that for certain triumvirates, the matching events could have taken place at different evolutionary times. In contrast to a few polypeptide ligands interacting with more than one receptor, we found that many small nonpeptide ligands have been paired with two or more plasma membrane receptors, nuclear receptors, or channels. The observation that many small ligands are paired with more than one receptor type highlights the utilitarian use of a limited number of cellular components during metazoan evolution. These conserved ligands are ubiquitous cell metabolites likely favored by natural selection to establish novel regulatory networks. They likely possess structural features useful for designing agonistic and antagonistic drugs to target diverse receptors.     

Chemoimmunotherapy: reengineering tumor immunity

Cancer chemotherapy drugs have long been considered immune suppressive. However, more recent data indicate that some cytotoxic drugs effectively treat cancer in part by facilitating an immune response to the tumor when given at the standard dose and schedule. These drugs induce a form of tumor cell death that is immunologically active, thereby inducing an adaptive immune response specific for the tumor. In addition, cancer chemotherapy drugs can promote tumor immunity through ancillary and largely unappreciated immunologic effects on both the malignant and normal host cells present within the tumor microenvironment. These more subtle immunomodulatory effects are dependent on the drug itself, its dose, and its schedule in relation to an immune-based intervention. The recent approvals of two new immune-based therapies for prostate cancer and melanoma herald a new era in cancer treatment and have led to heightened interest in immunotherapy as a valid approach to cancer treatment. A detailed understanding of the cellular and molecular basis of interactions between chemotherapy drugs and the immune system is essential for devising the optimal strategy for integrating new immune-based therapies into the standard of care for various cancers, resulting in the greatest long-term clinical benefit for cancer patients.     

纳米技术在药物靶向治疗方面的现状和应用前景

纳米技术应用于药物载体的研究一直是近年生物医学所关注的热点。纳米药物载体在实现靶向性给药、缓释药物、提高难溶性药物与多肽药物的生物利用度、降低药物的毒副作用等方面表现出明显的优势。本文就近些年常见的纳米载药体的种类及其特性、常用制备方法、靶向治疗方面的研究进行综述,并对未来发展前景进行展望。     

Analysis of the internal nuclear matrix. Oligomers of a 38 kD nucleolar polypeptide stabilized by disulfide bonds

When rat liver nuclei are treated with the sulfhydryl cross-linking reagent sodium tetrathionate (NaTT) prior to nuclease treatment and extraction with 1.6 M NaCl, residual nucleoli and an extensive non-chromatin intranuclear network remain associated with the nuclear envelope. Subsequent treatment of this structure with 1 M NaCl containing 20 mM dithiothreitol (DTT) solubilizes the intranuclear material, while the nuclear envelope remains structurally intact. We have isolated and partially characterized a major polypeptide of the disulfide-stabilized internal nuclear matrix. The polypeptide, which has an apparent molecular mass 38 kD and isoelectric point 5.3, has been localized to the nucleolus of rat liver nuclei by indirect immunofluorescence using a specific polyclonal chicken antiserum. Based on its molecular mass, isoelectric point, intracellular localization and amino acid composition, the 38 kD polypeptide appears to be analogous to the nucleolar phosphoprotein B23 described by Prestayko et al. (Biochemistry 13 (1974) 1945) [20]. Immunologically related polypeptides have likewise been localized to the nucleoli of both hamster and human tissue culture cell lines as well as the cellular slime mold Physarum polycephalum. By immunoblotting, a single 38 kD polypeptide is recognized by the antiserum in rat, mouse, hamster and human cell lines. The antiserum has been utilized to investigate the oligomeric structure of the 38 kD polypeptide and the nature of its association with the rat liver nuclear matrix. By introducing varying numbers of disulfide bonds, we have found that the 38 kD polypeptide becomes incorporated into the internal nuclear matrix in a two-step process. Soluble disulfide-bonded homodimers of the polypeptide are first formed and then are rendered salt-insoluble by more extensive disulfide cross-linking.     

Cellular laminin-binding protein and Venezuelan equine encephalomyelitis virus replication in Vero, 293 and 9S2 cells

The level of laminin-binding protein (LBP) expression on cellular membranes was studied in three cell lines including 293 cells transformed by plasmide with human LBP gene. Vero cells show a high level of LBP on the cell surfaces and demonstrate a high level of the Venezuelan equine encephalomyelitis (VEE) virus replication. The inhibition of VEE virus replication was more than 200 times as much after treatment of Vero cell surfaces with monoclonal antibodies to human LBP. 293 cells have more low level of LBP on their surfaces but being transformed by plasmide with LBP human gene these cells showed an increase in the level of cellular LBP. The VEE virus replication in transformed cells (9S2) was more than 2000 times higher compared to 293 cells. The results obtained demonstrate a principal role of cellular LBP in VEE virus entry into mammalian cells. It can be proposed that LBP is a key cellular protein at the early stage of VEE virus replication in cells. So, LBP might be a target protein for development of some new generation of antiviral drugs that would be able to inhibit (enhance) the alphavirus replication in human cells.     

LaRbp38: a Leishmania amazonensis protein that binds nuclear and kinetoplast DNAs

Leishmania amazonensis causes a wide spectrum of leishmaniasis. There are no vaccines or adequate treatment for leishmaniasis, therefore there is considerable interest in the identification of new targets for anti-leishmania drugs. The central role of telomere-binding proteins in cell maintenance makes these proteins potential targets for new drugs. In this work, we used a combination of purification chromatographies to screen L. amazonensis proteins for molecules capable of binding double-stranded telomeric DNA. This approach resulted in the purification of a 38kDa polypeptide that was identified by mass spectrometry as Rbp38, a trypanosomatid protein previously shown to stabilize mitochondrial RNA and to associate with nuclear and kinetoplast DNAs. Western blotting and supershift assays confirmed the identity of the protein as LaRbp38. Competition and chromatin immunoprecipitation assays confirmed that LaRbp38 interacted with kinetoplast and nuclear DNAs in vivo and suggested that LaRbp38 may have dual cellular localization and more than one function.     

Considerations in the design of possible cell cycle effective drugs

Antineoplastic agents are known to induce differential cytotoxic and cytostatic effects throughout the cell cycle. Many drugs have greater toxicity for cycling cells and act selectively at one or more phases of the cycle and may cause partial synchrony of surviving cells. However, these observations have been generally carried out on in vitro systems only and present a variety of complexities and pitfalls. Furthermore, human tumours are often characterized by a relatively low fraction of proliferating cells and present a large cellular heterogeneity as far as their cytogenetic, cytokinetic, and clonogenic features and their responses to drugs are concerned. Therefore, resistance to chemotherapy is due to various factors characterizing, in some instances, each individual tumour. In spite of the advent of technological advances such as flow cytometry, it is still difficult to design kinetic-orientated therapies especially for the treatment of solid tumours. Consequently, it is also difficult to design protocols based on cell cycle effective drugs. The possibility remains, at least for the moment, to stratify tumours according to their cellular heterogeneity. Different protocols could then be assigned to classes of tumours. Such an approach could be completed by further advances in the cellular monitoring of individual tumours.     

一种多肽固相合成方法与纯化策略研究

目的: 多肽与小分子化学药物相比,具有生物活性高、特异性强、不容易产生耐药性等特点,是目前新型药物研发的重点领域。多肽的合成直接影响到多肽药物的作用机制以及药物效果,因此需要建立一种更加便捷、高效的多肽合成方法。方法: 采用Fmoc固相合成法合成多肽HF01,通过比较氨基酸连接的反应体系以及氨基酸脱保护的反应体系,从中确定最优体系。利用乙酰化基团进行肽链末端保护,经肽链剪切制备干燥的粗肽,最后采用高效液相色谱仪与高分辨质谱仪联用对粗肽进行纯化。结果: 确定多肽合成的连接和脱保护反应体系,并获得纯度高达98.3%的线性多肽。结论: 建立了一种高效、便捷的多肽合成及纯化方法,提高了实验室合成多肽的效率,为多肽类药物的研发提供技术支撑。