Molecular Cloning and Bioinformatics Analysis of TypeⅢSecretion System Effector Protein Va1686 Gene of Vibrio alginolyticus

In this study, Va 1686 gene was cloned from Vibrio alginolyticus . The total length of the gene is 1 164 bp, and it could encode 387 amino acids. The physicochemical properties, protein structure, genetic evolutionary relationship and antigenic characteristics of the effect protein Va1686 of V. alginolyticus HY9901 type Ⅲ secretion system were studied and analyzed by bioinformatics methods and tools. The results showed that Va1686 is a stable hydrophilic and acidic protein without a transmembrane region and a signal peptide, and secondary structure to α-helix. The evolutionary analysis showed that V. alginolyticus HY9901 and V. harveyi were clustered together, which indicated that the genetic relationship between the two species was the closest. Va1686 contains a Fic superfamily conserved domain associated with cell division. Bioinformatics analysis showed that the B-cell preponderant epitopes of Va1686 might be localized in the regions of 48-49, 82-85, 125-126, 150-153, 185-186, 236-237 and so on. The 3D structure model of Va1686 subunit was simulated by SWISS-MODEL software and it was found that the vopS of V. parahaemolyticus was similar and the similarity was 89.46%. In this study, the feasibility of Va1686 as a common antigen of Vibrio was verified from the perspective of bioinformatics, which laid the foundation for the next step in vaccine development.

Molecular Cloning and Bioinformatics Analysis of TypeⅢSecretion System Effector Protein HY 322 Gene of Vibrio alginolyticus

In this study,Hy322 gene was cloned from Vibrio alginolyticus.The total length of its gene was 969 bp,and it could encode 322 amino acids.The physicochemical properties,protein structure,genetic evolutionary relationship and antigenic characteristics of the effector protein Hy322 of V.alginolyticus HY9901 type Ⅲ secretion system were studied and analyzed by bioinformatics methods and tools.The results showed that Hy322 is an unstable hydrophilic and acidic protein without a transmembrane region and a signal peptide,and secondary structure to α-helix.The evolutionary analysis showed that V.alginolyticus HY9901 and V.harveyi were clustered together,which indicated that the genetic relationship between the two species was closest.HY322 contains a FliN super family conserved domain associated with Flagellar motor switch.Bioinformatics analysis showed that the B-cell preponderant epitopes of Hy322 might be localized in the regions of 32-33,100-102,138-140,215-216,235-238 and 246-249.The 3D structure model of Hy322 subunit was simulated by SWISS-MODEL software and itwas found that the yscQ of Yersinia were similar and the similarity was 42.25%.In this study,the feasibility of Hy322 as a common antigen of Vibrio was verified from the perspective of bioinformatics,which laid the foundation for the next step in vaccine development.

An enriched environment increases the expression of fibronectin type Ⅲ domain-containing protein 5 and brain-derived neurotrophic factor in the cerebral cortex of the ischemic mouse brain

Many studies have shown that fibronectin type III domain-containing protein 5(FDNC5) and brain-derived neurotrophic factor(BDNF) play vital roles in plasticity after brain injury. An enriched environment refers to an environment that provides animals with multi-sensory stimulation and movement opportunities. An enriched environment has been shown to promote the regeneration of nerve cells, synapses, and blood vessels in the animal brain after cerebral ischemia;however, the exact mechanisms have not been clarified. This study aimed to determine whether an enriched environment could improve neurobehavioral functions after the experimental inducement of cerebral ischemia and whether neurobehavioral outcomes were associated with the expression of FDNC5 and BDNF. This study established ischemic mouse models using permanent middle cerebral artery occlusion(pMCAO) on the left side. On postoperative day 1, the mice were randomly assigned to either enriched environment or standard housing condition groups. Mice in the standard housing condition group were housed and fed under standard conditions. Mice in the enriched environment group were housed in a large cage, containing various toys, and fed with a standard diet. Sham-operated mice received the same procedure, but without artery occlusion, and were housed and fed under standard conditions. On postoperative days 7 and 14, a beam-walking test was used to assess coordination, balance, and spatial learning. On postoperative days 16–20, a Morris water maze test was used to assess spatial learning and memory. On postoperative day 15, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex were analyzed by western blot assay. The results showed that compared with the standard housing condition group, the motor balance and coordination functions(based on beam-walking test scores 7 and 14 days after operation), spatial learning abilities(based on the spatial learning scores from the Morris water maze test 16–19 days after operation), and memory abilities(based on the memory scores of the Morris water maze test 20 days after operation) of the enriched environment group improved significantly. In addition, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex increased in the enriched environment group compared with those in the standard housing condition group. Furthermore, the Pearson correlation coefficient showed that neurobehavioral functions were positively associated with the expression levels of FDNC5 and BDNF(r = 0.587 and r = 0.840, respectively). These findings suggest that an enriched environment upregulates FDNC5 protein expression in the ipsilateral cerebral cortex after cerebral ischemia, which then activates BDNF protein expression, improving neurological function. BDNF protein expression was positively correlated with improved neurological function. The experimental protocols were approved by the Institutional Animal Care and Use Committee of Fudan University, China(approval Nos. 20160858 A232, 20160860 A234) on February 24, 2016.

Yersinia type Ⅲ effectors perturb host innate immune responses

The innate immune system is the first line of defense against invading pathogens. Innate immune cells recognize molecular patterns from the pathogen and mount a response to resolve the infection. The production of proinflammatory cytokines and reactive oxygen species, phagocytosis, and induced programmed cell death are processes initiated by innate immune cells in order to combat invading pathogens. However, pathogens have evolved various virulence mechanisms to subvert these responses. One strategy utilized by Gram-negative bacterial pathogens is the deployment of a complex machine termed the type Ⅲ secretion system(T3SS). The T3SS is composed of a syringe-like needle structure and the effector proteins that are injected directly into a target host cell to disrupt a cellular response. The three human pathogenic Yersinia spp.(Y. pestis, Y. enterocolitica, and Y. pseudotuberculosis) are Gramnegative bacteria that share in common a 70 kb virulence plasmid which encodes the T3 SS. Translocation of the Yersinia effector proteins(YopE, YopH, YopT, YopM, YpkA/YopO, and YopP/J) into the target host cell results in disruption of the actin cytoskeleton to inhibit phagocytosis, downregulation of proinflammatory cytokine/chemokine production, and induction of cellular apoptosis of the target cell. Over the past 25 years, studies on the Yersinia effector proteins have unveiled tremendous knowledge of how the effectors enhance Yersinia virulence. Recently, the long awaited crystal structure of YpkA has been solved providing further insights into the activation of the YpkA kinase domain. Multisite autophosphorylation by YpkA to activate its kinase domain was also shown and postulated to serve as a mechanism to bypass regulation by host phosphatases. In addition, novel Yersinia effector protein targets, such as caspase-1, and signaling pathways including activation of the inflammasome were identified. In this review, we summarize the recent discoveries made on Yersinia effector proteins and their contribution to Yersinia pathogenesis.

釉基质蛋白对人牙周膜细胞形成Ⅰ型胶原、Ⅲ型胶原的影响

目的 :观察釉基质蛋白对体外培养的人牙周膜细胞形成Ⅰ型胶原、Ⅲ型胶原的影响。方法 :改良组织块法培养人牙周膜细胞 ,免疫细胞化学方法和图像分析方法观察细胞形成Ⅰ型胶原、Ⅲ型胶原的能力。结果 :5 0、10 0、2 0 0mg/L的釉基质蛋白可以促进牙周膜细胞合成Ⅰ、Ⅲ型胶原 ,其中 ,以 10 0mg/L釉基质蛋白的促Ⅰ型胶原合成作用最明显 ,5 0mg/L釉基质蛋白的促Ⅲ型胶原合成作用最明显。但是 ,这种促进作用有一定的时间性。结论 :一定浓度的釉基质蛋白可以促进牙周膜细胞形成Ⅰ型胶原。

类鼻疽杆菌Ⅲ型分泌系统BPSS1395蛋白表达及其抗体制备与鉴定

目的重组表达类鼻疽杆菌Ⅲ型分泌系统蛋白BPSS1395,利用其抗体检测该蛋白在细菌中的分布。方法以pET-22b为表达系统,采用DNA重组技术在大肠杆菌中表达BPSS1395蛋白;用纯化重组蛋白免疫新西兰大白兔,Western blot及ELISA法鉴定其免疫学性质;以制备的抗血清Western blot分析该蛋白的亚细胞定位。结果从类鼻疽杆菌BPC006株基因组DNA中PCR得到了BPSS1395目的基因,并成功构建pET-22b-BPSS1395重组质粒,转化到E.coli宿主菌BL21(DE3)经IPTG诱导表达、纯化得到了相对分子质量为32×10~3的高纯度BPSS1395蛋白,制备的兔抗血清ELISA效价均高达1∶1 280 000,并能与目的蛋白发生特异性抗原抗体反应。亚细胞分离后BPSS1395在类鼻疽杆菌中主要定位于细胞质。结论重组表达了具有生物活性的BPSS1395蛋白,制备了其特异性多克隆抗体,证明了该蛋白定位于细胞质。

胶原蛋白Ⅰ、胶原蛋白Ⅲ在糖尿病大鼠血管病变中的表达及中药的干预

[目的]对中药干预下的糖尿病大鼠动脉损伤模型的胶原蛋白的表达进行研究,为糖尿病大鼠动脉损伤纤维病变学说和中药干预糖尿病血管并发症的可行性提供实验学依据。[方法]雄性SD大鼠48只,按随机数字表法随机分为A-正常对照组,B-糖尿病对照组,C-中药治疗组,D-二甲双胍治疗组,其中B、C、D 3组为糖尿病模型组,观察各组大鼠股动脉中胶原蛋白Ⅰ、Ⅲ的含量。[结果]糖尿病模型组与正常对照组比较,胶原蛋白Ⅰ、胶原蛋白Ⅲ均明显升高;各治疗组治疗后与糖尿病对照组比较,胶原蛋白Ⅰ、Ⅲ表达明显下降;中药治疗组与西药治疗组比较,胶原蛋白Ⅰ、Ⅲ表达下降(P<0.05)。[结论]胶原蛋白Ⅰ、Ⅲ在中、晚期糖尿病大鼠的大血管中显著增加,提示糖尿病大血管病变可能与胶原蛋白有关;中药组方加味桃核承气汤能有效降低致纤维化因子胶原蛋白在实验性糖尿病大血管病变中的表达,对糖尿病大血管病变有改善作用。

植物TFⅢA类型锌指蛋白的研究进展

锌指蛋白作为一种转录调控因子,在植物的生长发育中起着重要作用.近年来,在克隆植物锌指蛋白基因方面取得了很大进展,特别是对于植物TFⅢA类型锌指蛋白的研究.目前已经获得了近30个TFⅢA类型锌指蛋白的基因克隆.已发现的TFⅢA锌指蛋白参与了一些重要过程的调控,如:形态建成、雄配子产生、胚的发育、胁迫反应等.

恶性疟原虫组氨酸富集蛋白Ⅱ、Ⅲ的序列多态性分析

目的分析恶性疟原虫富组氨酸蛋白Ⅱ/Ⅲ（Pf HRPⅡ/Ⅲ）的序列多态性。方法采集云南疟疾流行区恶性疟患者血样20份,血涂片后镜检,并进行疟疾快速诊断试剂检测（RDTs）,同时提取各血样中恶性疟原虫基因组DNA,进行PCR扩增Pfhrp2和Pfhrp3核酸片段并测序。使用Bioedit软件对Pfhrp2和Pfhrp3基因序列进行比对,使用TRANSEQ软件推导出其编码的氨基酸序列。结果 20份血样经镜检和RDTs检测均为恶性疟原虫阳性。PCR扩增结果显示,各血样的Pfhrp2核酸片段约389～986 bp,Pfhrp3核酸片段大小约329～640 bp,应用测序获得的核酸序列推导出相应的氨基酸序列,Pf HRPⅡ氨基酸残基序列以1型（AHHAHHVAD）起始并最终以12型（AHHAAAHHEAATH）作为结尾,Pf HRPⅡ特征性氨基酸残基重复序列数量相对较多的分别有7型（AHHAAD）、2型（AHHAHHAAD）和6型（AHHATD）;Pf HRPⅢ含有重复较多的型别是16型（AHHAAN）和17型（AHHDG）;Pf HRPⅡ和Pf HRPⅢ均未发现11型（AHN）。结论 20份恶性疟患者血样中Pfhrp2和Pfhrp3存在诸多的核酸变异,Pf HRPⅡ和Pf HRPⅢ共享一些特征性重复序列。

致病菌Ⅲ型分泌系统特有效应蛋白的预测及其特有模体分析

目的对病原菌Ⅲ型分泌系统(TTSS)效应蛋白在非致病菌中进行直系同源基因预测,以获得病原菌Ⅲ型分泌系统特有效应蛋白,并进一步对特有效应蛋白模体构成进行分析,旨在更深入地认识TTSS效应蛋白,为理论研究和生物学实验提供参考。方法利用彼此最佳blast方法对效应蛋白在构建的非致病性细菌蛋白质数据库中进行直系同源基因预测,并利用Inter Pro Scan对预测获得的特有效应蛋白序列进行模体搜索分析。结果在49个收集整理的致病菌Ⅲ型分泌系统效应蛋白序列中,有18个效应蛋白在非致病菌中存在直系同源基因,31个效应蛋白(即TTSS特有效应蛋白)在非致病菌中没有直系同源基因;对31个Ⅲ型分泌系统特有效应蛋白序列进行模体分析,获得了12个效应蛋白特有模体。结论 31个致病菌Ⅲ型分泌系统特有效应蛋白序列的获得,为更精确地在致病性细菌基因组内预测获得新的效应蛋白序列奠定了基础;12个效应蛋白特有模体的获得及其基因本体注释分析进一步理解了效应蛋白的作用机制。

六味地黄汤对5/6肾切除大鼠NF-κB、MCP-1、Col-Ⅲ表达的影响

目的观察六味地黄汤对5/6肾切除大鼠残肾转录因子-核因子κB(NF-κB)、单核细胞趋化因子(MCP-1)及Ⅲ型胶原(Col-Ⅲ)表达的影响,探讨六味地黄汤抑制肾间质纤维化进展的作用机制。方法按照随机数字表法将60只SD雄性大鼠分为5组:空白组、假手术组、模型组、依那普利组、六味地黄汤组,每组12只,后三组行5/6肾切除术诱导大鼠肾衰模型,假手术组同期手术,但不损及肾脏。造模术后3 d进行灌胃干预。灌胃8周后处死各组大鼠,观察各组大鼠残肾组织形态学变化并用免疫组化法检测大鼠残肾NF-κB、MCP-1、Col-Ⅲ的表达。结果 (1)观察5/6肾切除大鼠残肾组织细胞形态学,与模型组相比六味地黄汤、依那普利组可减轻大鼠肾间质损害及纤维化程度;(2)免疫组化半定量分析显示六味地黄汤组肾皮质的NF-κB、MCP-1及Col-Ⅲ表达均明显低于模型组(P<0.05),与依那普利组差异无统计学意义(P>0.05)。结论六味地黄汤可能通过下调NF-κB、MCP-1及Col-Ⅲ的表达,减少细胞外基质的积聚,减轻炎症反应和纤维化程度,抑制5/6肾切除大鼠肾间质纤维化进展,可作为慢性肾衰竭的辅助用药。

黄单胞菌Ⅲ型分泌系统效应蛋白的研究进展

黄单胞菌借助保守的III型分泌系统,将多个效应蛋白注入植物细胞,克服宿主的防卫,利于黄单胞菌在植物体内发挥毒性功能。最近对III型效应蛋白致病机理开展了大量研究,结果发现具有酶功能的效应蛋白在黄单胞菌及其宿主间的相互作用中发挥非常重要的作用。此外,黄单胞菌存在一类独特的III型效应蛋白(Avr Bs3家族)。迄今为止,仅在黄单胞菌和雷尔氏菌(Ralstonia solanacearum)中发现Avr Bs3家族效应蛋白,Avr Bs3家族通过模拟转录激活子来操纵寄主植物易感基因的表达。

妇炎净合剂对NIH3T3成纤维细胞体外培养及Ⅲ型胶原蛋白mRNA表达的影响

目的 探讨妇炎净合剂对NIH3T3成纤维细胞增殖及Ⅲ型胶原蛋白mRNA表达的影响。方法 体外培养NIH3T3成纤维细胞 ,采用MTT法测定细胞增殖、RT PCR法测定Ⅲ型胶原蛋白mRNA的表达。结果 妇炎净合剂有抑制体外培养的成纤维细胞增殖及Ⅲ型胶原蛋白mRNA表达的作用 ,且妇炎净合剂各浓度组呈现浓度依赖性 ,随浓度增高抑制作用增强。结论 妇炎净合剂有抑制成纤维细胞增殖及在逆转录水平抑制胶原蛋白表达的作用 。

人表皮生长因子受体Ⅲ型突变体胞外区的克隆表达和鉴定

目的构建含表皮生长因子(EGF)受体Ⅲ型突变体胞外区基因(vⅢECD)的重组质粒并进行表达和鉴定。方法应用PCR方法扩增EGFRvⅢ ECD片段,将其T-A克隆和测序,再将目的基因插入GST融合表达载体pGEX-4T-1中进行表达。采用双酶切鉴定插入序列的正确性,用SDS-PAGE及Western blotting分析融合蛋白的表达。结果测序结果证实插入DNA序列与EGFR胞外区序列完全一致;双酶切鉴定表明,EGFRvⅢ ECD序列已经正确克隆到GST融合表达载体中。SDS-PAGE电泳显示融合蛋白在E.coli BL21(DE3)中以包涵体形式表达,重组融合蛋白GST-vⅢECD的表达量占菌体总蛋白的15%以上。Western blotting分析证实重组融合蛋白可以被EGFR特异性抗体所识别。结论成功构建了融合表达载体(pGEX-4T-1/vⅢECD),并进行了融合蛋白的诱导表达和鉴定,可进一步用于EGFRvⅢ功能及免疫学研究。

维甲酸对转化生长因子β1诱导的HFL-I细胞Ⅲ型胶原、STAT3和PIAS3表达的影响

目的:研究全反式维甲酸(ATRA)对转化生长因子β1(TGF-β1)诱导的人胚肺成纤维细胞(HFL-I)中Ⅲ型胶原(collagenⅢ)、信号转导子和转录激活子3(STAT3)和活化STAT3蛋白抑制剂(PIAS3)表达的影响。方法:体外培养HFL-I细胞,5μg/L TGF-β1诱导0 h、6 h、12 h、24 h、48 h和72 h后,RT-PCR法检测colla-genⅢ、STAT3和PIAS3 mRNA表达,诱导0 d、1 d、3 d和5 d后,Western blotting法检测STAT3和p-STAT3蛋白表达。不同浓度维甲酸干预,24 h后用RT-PCR法检测collagenⅢ、STAT3和PIAS3 mRNA表达,3 d后用Westernblotting法检测STAT3和p-STAT3蛋白表达。结果:TGF-β1诱导后,HFL-I细胞中collagenⅢ和STAT3 mRNA表达明显上调,PIAS3 mRNA表达明显下调,STAT3和p-STAT3蛋白表达明显上调(P<0.05)。各浓度ATRA都下调TGF-β1诱导的HFL-I细胞中collagenⅢ、STAT3 mRNA和STAT3、p-STAT3蛋白的表达,上调PIAS3 mR-NA表达(P<0.05)。结论:ATRA可通过抑制TGF-β1诱导的HFL-I细胞collagenⅢ和STAT3表达、上调PIAS3表达而起到抗肺纤维化作用。

肠出血性大肠杆菌Ⅲ型分泌系统效应因子与宿主细胞相互作用研究进展

肠出血性大肠杆菌(Enterohemorrhagic Escherichia coli,EHEC)通过其Ⅲ型分泌系统将效应因子注入到宿主细胞内,破坏宿主细胞内的多种信号通路从而有利于细菌的感染及定植。近年来对于EHEC Ⅲ型分泌系统效应因子与宿主细胞相互作用研究成为EHEC致病机制研究新的热点,研究表明,除了经典的效应因子外,一些新发现的效应因子在细菌的致病过程中也发挥着重要作用,有些效应因子能够抑制宿主细胞内正常的信号通路,有些效应因子还具有抑制细胞凋亡,干扰炎症信号通路和抑制吞噬的作用。这些发现揭示了EHEC效应因子具有多种功能,它们通过与宿主细胞间的相互作用,在细菌的感染过程中发挥着重要作用。

釉基质蛋白对大鼠骨髓基质细胞合成Ⅰ、Ⅲ型胶原的影响

目的:探讨釉基质蛋白(EMPs)对大鼠骨髓基质细胞(rMSCs)合成Ⅰ、Ⅲ型胶原的影响。方法:采用全骨髓法培养rMSCs,通过免疫细胞化学和图像分析方法观察EMPs对rMSCs合成Ⅰ、Ⅲ型胶原的影响。结果:实验组胶原合成明显强于对照组。其中,以100mg/LEMPs促Ⅰ、Ⅲ型胶原合成作用最明显,且这种促进作用有一定的时间性。结论:一定浓度的EMPs可以有效促进rMSCs合成Ⅰ、Ⅲ型胶原。

Therapeutic potential of exercise-hormone irisin in Alzheimer's disease

Irisin is a myokine that is generated by cleavage of the membrane protein fibronectin type Ⅲ domain-containing protein 5(FNDC5) in response to physical exercise. Studies reveal that irisin/FNDC5 has neuroprotective functions against Alzheimer's disease, the most common form of dementia in the elderly, by improving cognitive function and reducing amyloid-β and tau pathologies as well as neuroinflammation in cell culture or animal models of Alzheimer's disease. Although current and ongoing studies on irisin/FNDC5 show promising results, further mechanistic studies are required to clarify its potential as a meaningful therapeutic target for alleviating Alzheimer's disease. We recently found that irisin treatment reduces amyloid-β pathology by increasing the activity/levels of amyloid-β-degrading enzyme neprilysin secreted from astrocytes. Herein, we present an overview of irisin/FNDC5's protective roles and mechanisms against Alzheimer's disease.

Diverse interactions of five core type Ⅲ effectors from Ralstonia solanacearum with plants

Ralstonia solanacearum is a widespread plant bacterial pathogen that can launch a range of type Ⅲ effectors(T3Es)to cause disease.In this study,we isolate a pathogenic R.solanacearum strain named P380 from tomato rhizosphere.Five out of 12 core T3Es of strain P380 are introduced into Pseudomonas syringae DC3000D36E separately to determine their functions in interacting with plants.DC3000D36E that harbors each effector suppresses FliC-triggered Pti5 and ACRE31 expression,ROS burst,and callose deposition.RipAE,RipU,and RipW elicit cell death as well as upregulate the MAPK cascades in Nicotiana benthamiana.The derivatives RipC1^(△DDXDX(T/V))and RipW^(△DDKXXQ)but not RipAE^(K310R) fail to suppress ROS burst.Moreover,RipAE^(K310R) and RipW^(△DDKXXQ) retain the cell death elicitation ability.RipAE and RipW are associated with salicylic acid and jasmonic acid pathways,respectively.RipAE and RipAQ significantly promote the propagation of DC3000D36E in plants.The five core T3Es localize in diverse subcellular organelles of nucleus,plasma membrane,endoplasmic reticulum,and Golgi network.The suppressor of G2 allele of Skp1 is required for RipAE but not RipU-triggered cell death in N.benthamiana.These results indicate that the core T3Es in R.solanacearum play diverse roles in plantpathogen interactions.

黄单胞杆菌Ⅲ型效应子研究进展

许多黄单胞杆菌通过Ⅲ型分泌系统将效应子注入到寄主细胞中,引起寄主的免疫反应或感病。最近的研究提供了大量的关于Ⅲ型效应子作为致病因子或激发子同寄主互作的实验数据。笔者综述了黄单胞杆菌Ⅲ型效应子的分类及avrbs3、AvrRxv/YopJ、XopN、XopD家族的主要功能,重点介绍了Ⅲ型效应子的酶活性功能在同寄主互作过程中发挥的重要作用,如XopD的SUMO化作用;AvrBs3家族效应子在调节寄主基因转录方面的作用;XopN抑制PAMP介导的植物免疫反应的功能等。论文还对一些研究深入的Ⅲ型效应子及其与寄主的互作进行了比较详细的评述,讨论Ⅲ型效应子的研究对于植物抗病基因工程的影响及重要意义,并对Ⅲ型效应子的研究方向进行了展望。