沙眼衣原体3种二硫键异构酶基因表达研究

目的研究3种二硫键(dsb)异构酶基因dsbB、dsbD、dsbG在沙眼衣原体(Chlamydia trachornatis,Ct)发育周期内的表达水平,探讨它们同Ct不同发育形式包括原体(EB)及始体(RB)的关系。方法以25 cm~2细胞培养瓶培养小鼠成纤维细胞L_2,待L_2细胞长成致密单层后,用Ct血清型F/IC-Cal-13感染,感染后每4 h收获一次细胞,提取总RNA,用基因特异性引物反转录后,RT-PCR分别扩增dsb基因转录的cDNA,将产物在DNA凝胶成像系统内检测,半定量分析cDNA产量,从而分析Ct发育周期内3种dzb基因的表达水平。结果在感染后12 h开始检测到dsbG表达,16 h开始检测到dsbB、dsbD表达。所不同的是dsbG在感染后12 h开始,表达一直上升,持续维持在较高水平直到整个发育周期完成,EB释放。dsbB表达水平较低,于28 h达到高峰,随后下降;dsbD表达水平介于dsbB和dsbG之间,与dsbB相似,dsbD的表达于2,4～28 h达峰值,随后下降。结论在Ct的发育周期中,同一时间点dsbB、dsbD、dsbG的表达水平存在差异;就每一种dsb而言,不同时间点的表达水平也不同。总体上,Ct发育的早期阶段(由EB到RB),Dsb蛋白参与的程度不高,dsbG的转录在感染后12 h开始,并稳定上升,直到完成整个发育周期;而dsbB、dsbD则在感染后16 h开始表达并于20～28 h出现峰值,然后下降直到感染后40 h。以上3种Dsb蛋白,有可能在Ct的感染及发育过程中起作用。     

二硫键异构酶在神经变性疾病中的调控机制

二硫键异构酶(protein-disulphide isomerase,PDI)作为巯基-二硫键交换反应的催化剂,可促进蛋白二硫键的生成和错配二硫键的重排;同时它具有分子伴侣活性,能抑制错误折叠蛋白的聚集。在神经变性疾病如帕金森症、阿尔兹海默症、肌萎缩侧索硬化症、多聚谷氨酰胺疾病中,PDI可通过抑制错误折叠蛋白的聚集以及遍在蛋白化,起到神经保护作用。但是PDI能被过量的一氧化氮亚硝基化,导致其蛋白质构象改变和功能障碍,影响神经元的连通性和可塑性,触发神经元的凋亡通路。本文就最新研究综述了PDI的结构功能、调控机制及在神经变性疾病的作用。     

MUC1粘蛋白—肿瘤生物治疗的新靶点

MUC1粘蛋白是一种高分子量糖蛋白 ,存在于正常腺细胞和多种癌细胞表面 ,由于它特有的免疫学特性 ,即在癌变细胞表面异常、高度表达 ,具有肿瘤特异性抗原 ,并可非MHC限制性活化CTL ,使之成为肿瘤生物治疗的一种理想靶分子。目前已有多项基于MUC1进行的有关研究 ,有些已用于临床 ,本文将近些年在MUC1肿瘤生物治疗方面的研究做一综述。     

不同人大肠癌细胞内质网合成的二硫键异构酶研究

目的 :探索 PDI与癌细胞生物学特性之间的关系。方法 :应用不同侵袭力的大肠癌细胞系 CCL -2 2 9(高侵袭 )和 CX- 1(低侵袭 ) ,通过流式细胞术分析两者 PDI含量的差别 ,以及经全反式维甲酸 (RA)诱导后PDI的变化 ;间接免疫荧光法观察细胞中 PDI的表达情况。结果 :CX- 1中 PDI的含量高于 CCL - 2 2 9;随诱导天数的增加 ,同一细胞系中 PDI含量增加。结论 :PDI与癌细胞的侵袭力呈负相关关系 ;PDI与分化呈正相关关系。     

家兔各组织蛋白二硫键异构酶的活性及含量研究

目的　探讨蛋白二硫键异构酶 (PDI)的生物学功能及与微粒体的关系。方法　应用改良的Hill son方法及酶联免疫技术 ,测定家兔不同组织细胞内PDI的活性及其含量。结果　家兔不同组织细胞内均有PDI分布 ,但酶活性及含量差异显著 ,在分泌功能旺盛的胰腺细胞、肝细胞其含量占细胞总蛋白的 2～ 6 % ,是肌细胞的 10 0倍 ,酶比活性为 4～ 2 4unit/g ,约为肌细胞的 80～ 40 0倍 ,不同细胞微粒体获得率明显不同 ,单位重量微粒体蛋白含量基本相同。结论　不同细胞内质网含量不同 ,而单位重量内质网的蛋白种类和含量具有一定保守性     

HIV—1整合酶：艾滋病治疗的新靶点

目前,抗逆转录病毒的治疗虽然已经有了显著进展,但寻找价格低廉, 活性更强的抗HIV药物仍在继续,以HIV pol基因的两个产物逆转录酶和蛋白酶为靶点,美国食品与药品管理局（FDA）批准了9种逆转录酶抑制剂和5种蛋白酶抑制剂作为临床抗艾滋病药物,目前对HIV的防要是采取转录酶抑制剂和蛋白酶抑制合用的联合疗法,但此种方法不能完全清除病毒,停药后产生反跳,病情反复,HIV复制过程中还有另一个重要的酶一整合酶,使病毒基因组整合于宿主细胞染色体,病毒在体内长期潜伏,整合酶是HIV自身特有的酶,也是一个抗HIV药物设计的理想靶点,本文主要介绍HIV－1整合酶的结构,在病毒复制过程中的功能,以及整合酶抑制剂为抗HIV药物设计靶点的研究进展。     

人类一条新的类蛋白质二硫键异构酶cDNA的克隆和表达

利用SMART技术构建了人胎脑cDNA文库，通过大规模测序筛选出一条1645bp的人类cDNA。此cDNA含有一个888bp的开放阅读框（ORF），编码一个296个氨基酸的蛋白质，预测分子量34．0KD。与目前数据库中序列比较，该cDNA编码的蛋白质与蛋白质二硫键异构酶的同源性达36％，命名为类蛋白质二硫键异构酶（PDI－L）基因，多组织Northern blot分析显示PDI－L cDNA在心、脑、肝肾等组织中均有表达，该cDNA的读框片段正确插入到改造后的pBV220表达载体中，获得了预期的表达蛋白。     

腺苷受体A3:新的抗肿瘤靶点

腺苷在一定浓度下对血管形成、免疫逃避、肿瘤生长有很大的影响。腺苷由细胞释放后通过与细胞表面特异性腺苷受体结合对细胞的功能起调节作用。腺苷受体A3（A3 adenosine receptor, A3AR）在腺苷调节细胞活力和生长中起关键作用，并且在很多肿瘤中表达增高，A3AR可能成为肿瘤诊断标志物和治疗靶点。     

B7-H4——免疫调控以及肿瘤治疗的新靶点

B7-H4又称B7sl或B7x,是B7家族中的最新发现的一个新成员,它能通过抑制T细胞的增殖、细胞因子的产生和细胞周期的进程来负性调控T细胞的免疫应答,同时大量表达B7-H4还可以促进上皮细胞的恶性转化,保护表皮细胞免于失巢凋亡,在肿瘤的发生,进展和转归中发挥重要作用.对B7-H4信号通路的进一步的研究必将为自身免疫性疾病、病毒感染性疾病和器官移植后排斥反应中T细胞介导的免疫应答调控提供了新的途径,同时也为肿瘤的诊断、治疗提供崭新的策略.     

NLRP3: A promising therapeutic target for autoimmune diseases

NLRP3, a member of nucleotide-binding domain-(NOD) like receptor family, can be found in large varieties of immune and non-immune cells. Upon activation, the NLRP3, apoptosis-associated speck-like protein (ASC) and pro-caspase-1 would assemble into a multimeric protein, called the NLRP3 inflammasome. Then the inflammasome promotes inflammation (through specific cleavage and production of bioactive IL-1β and IL-18) and pyroptotic cell death. Previous studies have indicated the importance of NLRP3 in regulating innate immunity. Recently, numerous studies have revealed their significance in autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc) and inflammatory bowel disease (IBD). In this review, we will briefly discuss the biological features of NLRP3 and summarize the recent progression of the involvement of NLRP3 in the development and pathogenesis of autoimmune diseases, as well as its clinical implications and therapeutic potential.     

Pentraxin 3: A promising therapeutic target for autoimmune diseases

Pentraxin 3 (PTX3) is a prototypic humoral soluble pattern recognition molecule that exerts a pivotal role in innate immune response and inflammation, as well as in tissue damage and remodeling. Recently, emerging evidence has revealed that PTX3 is involved in the occurrence and development of various autoimmune diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), ankylosing spondylitis (AS), systemic sclerosis (SSc), inflammatory bowel disease (IBD), multiple sclerosis (MS) and psoriasis, etc. In this review, we have succinctly summarized the complex immunological functions of PTX3 and mostly focused on recent findings of the pleiotropic activities played by PTX3 in the pathogenesis of autoimmune diseases, aiming at hopefully offering possible future therapeutic alternatives.     

Ryanodine receptor: a new therapeutic target to control diabetic cardiomyopathy

Diabetes mellitus is a major risk factor for cardiovascular complications. Intracellular Ca(2+) release plays an important role in the regulation of muscle contraction. Sarcoplasmic reticulum Ca(2+) release is controlled by dedicated molecular machinery, composed of a complex of cardiac ryanodine receptors (RyR2s). Acquired and genetic defects in this complex result in a spectrum of abnormal Ca(2+) release phenotypes in heart. Cardiovascular dysfunction is a leading cause for mortality of diabetic individuals due, in part, to a specific cardiomyopathy, and to altered vascular reactivity. Cardiovascular complications result from multiple parameters, including glucotoxicity, lipotoxicity, fibrosis, and mitochondrial uncoupling. In diabetic subjects, oxidative stress arises from an imbalance between production of reactive oxygen and nitrogen species and capability of the system to readily detoxify reactive intermediates. To date, the etiology underlying diabetes-induced reductions in myocyte and cardiac contractility remains incompletely understood. However, numerous studies, including work from our laboratory, suggest that these defects stem in part from perturbation in intracellular Ca(2+) cycling. Since the RyR2s are one of the well-characterized redox-sensitive ion channels in heart, this article summarizes recent findings on redox regulation of cardiac Ca(2+) transport systems and discusses contributions of redox regulation to pathological cardiac function in diabetes.     

Autophagy in brain tumors: a new target for therapeutic intervention

The role of autophagy, traditionally considered a cellular homeostatic and recycling mechanism, has expanded dramatically to include an involvement in discrete stages of tumor initiation and development. Gliomas are the most aggressive and also the most common brain malignancies. Current treatment modalities have only a modest effect on patient outcomes. Resistance to apoptosis, a hallmark of most cancers, has driven the search for novel targets in cancer therapy. The autophagy lysosomal pathway is one such target that is being explored in multiple cancers including gliomas and is a promising avenue for further therapeutic development. This review summarizes our current understanding of the autophagic process and its potential utility as a target for glioma therapy.     

MicroRNA-22-3p as a novel regulator and therapeutic target for autoimmune diseases

MicroRNAs (miRNAs) are a class of noncoding RNAs and have emerged as critical regulators of gene expression. Some miRNAs play important roles in regulating the function of the immune system and are involved in the pathogenesis of autoimmune diseases. Recent studies suggested that microRNA-22-3p (miR-22-3p) was able to regulate the function of several types of immune cells and may be involved in the development of autoimmune diseases. We systematically reviewed relevant literatures to provide a comprehensive review of the possible roles of miR-22-3p in autoimmune diseases. Published studies suggest that miR-22-3p can act as a novel regulator of autoimmune diseases via several pathways. More studies are needed to further elucidate the exact roles of miR-22-3p in autoimmune diseases. Treatment strategy targeting miR-22-3p is also a promising therapy for autoimmune diseases.     

The NLRP3 inflammasome: a therapeutic target for inflammation-associated cancers

ABSTRACT

Introduction: Inflammasomes are large multimeric intracellular complexes that are capable of maturation and secretion of pro-inflammatory cytokines, IL-1β and IL-18, in response to danger signal molecules. As a member of the inflammasome family, the NLRP3 inflammasome has recently been under intense investigation revealing its possible role in several human diseases especially cancers.

Areas covered: In this review, we will discuss the biology and mechanism of NLRP3 inflammasome activation, its role in specific types of tumors and the novel therapeutic modalities targeting this complex.

Expert opinion: The NLRP3 inflammasome and its components including the adapter apoptosis-associated speck-like (ASC) protein and caspase-1 impose different and sometimes contrasting effects in tumorigenesis depending on various contexts. Considering the novel role of this complex in the initiation and progression of neoplasia, the NLRP3 inflammasome and its pathways provide desirable therapeutic targets for prevention, treatment, and prognosis of certain types of cancer. To date, several agents have been introduced for this purpose, some of which have shown promising results in the clinic.     

Rituximab's new therapeutic target: the podocyte actin cytoskeleton

Therapeutic off-target activities are well recognized for small-molecule drugs. In contrast, monoclonal antibodies (mAbs) traditionally are believed to act specifically and lack off-target therapeutic effects. In this issue of Science Translational Medicine, Fornoni et al. show therapeutic benefit, through an off-target-mediated mechanism, of the mAb drug rituximab in recurrent focal segmental glomerulosclerosis (FSGS) after kidney transplantation. These data shed new light on FSGS pathogenesis and suggest new therapeutic interventions for proteinuric diseases.     

Carbonic anhydrase III: a new target for autoantibodies in autoimmune diseases

The objective of this study was to identify new autoantibodies that could be useful for the diagnosis of rheumatoid arthritis (RA) using immunoblotting on synovial membrane proteins which represent the best source of candidate RA autoantigens. A new target protein with a molecular weight of 26 kDa was found to be recognized by autoantibodies in RA sera and was identified using MALDI-TOF mass spectrometry and second-dimension electrophoresis as carbonic anhydrase III (CAIII). Three similar protein spots at 26 kDa were recognized by both human sera and monoclonal antibody (mAb) directed against CAIII on immunoblotting using the human recombinant CAIII. Interestingly, CAIII expression within the synovial membrane was not observed in non-RA patients and was differentially expressed among RA patients. The sensitivity of these new autoantibodies for RA, using an immunoenzymatic technique, was 17%. Specificity was high when comparing non-autoimmune diseases (100%), while it was found to be weak (67%) when comparing some other autoimmune diseases, and particularly systemic lupus erythematosus (SLE). In conclusion, this study demonstrates that these new autoantibodies against CAIII are not restricted to RA. However the expression of CAIII in the synovial membrane of RA warrants further investigation of the pathophysiological relevance of this finding.