失血性休克大鼠肝脏蛋白质的差异分析

 应用蛋白质双向凝胶电泳 (two-dimensional polyacrylamide gel electrophoresis, 2-DE) 技术,分析在急性重度失血性休克 (refractory hemorrhagic shock, RHS) 条件下,大鼠肝脏蛋白质组表达的差异.16 只雄性 Wistar 大鼠随机分成正常对照组 (sham hemorrhage shock, SHS) 和 RHS 模型组,每组 8 只.采用股动脉放血的方法制备模型,在规定时间内处死大鼠并分离肝脏,提取肝脏总蛋白质后进行 2-DE.运用 Image Master 2D Platinum v 5.0 凝胶图像分析软件对 2-DE 凝胶图像进行差异表达分析.有意义的差异蛋白质点用基质辅助激光解析电离飞行时间质谱进行肽质量指纹图谱分析,借助 Swiss-prot 数据库进行蛋白质搜索和鉴定.SHS 组和 RHS 组肝脏的 2-DE 图谱,分别平均识别到 698±11 和 700±13 个蛋白质点,SHS 组和 RHS 组肝脏间平均匹配率达88%～92 %.共发现 10 个差异有意义的蛋白质点,鉴定出了肿瘤抑制性抗原gp96、葡萄糖调节蛋白58、过氧还蛋白Ⅰ、细胞色素b5、谷胱甘肽转移酶、ATP合酶β亚单位、二磷酸果糖酶 B、三磷酸甘油醛脱氢酶等8种蛋白质.结果表明,以 2-DE 技术得到重复性和分辨率都较好的 2-DE图谱,并初步鉴定急性重度失血性休克后大鼠肝脏的差异表达蛋白质,为深入研究失血性休克的生理病理机制及寻找失血性休克预防和治疗的生物标志物提供了依据.     

慢性应激大鼠海马的比较蛋白质组学研究

慢性应激可造成海马神经细胞丢失、树突萎缩等损伤,但有关其损伤机制仍有很多问题不甚明了.为了寻找应激致海马损伤相关的重要蛋白质、从蛋白质水平揭示应激致海马损伤的分子机制,应用双向凝胶电泳(2-DE)技术分离对照组和束缚应激组大鼠海马组织总蛋白质,图像分析检测差异表达的蛋白质点,基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MSS)和数据库检索对差异表达的蛋白质点进行鉴定,并采用半定量的RT-PCR在mRNA水平验证2-DE结果.得到了分辨率较高、重复性较好的对照和束缚应激大鼠海马2-DE图谱,质谱分析和数据库检索鉴定了14个差异表达蛋白质点中的11个蛋白质,大多数差异蛋白的功能涉及能量代谢、信号传递等过程.研究结果为揭示应激致海马损伤的机制、提高机体的应激适应能力提供了理论依据.     

高畸形率水牛精子与正常水牛精子差异表达蛋白的分离和鉴定

旨在分析高畸形率和正常水牛精子的差异表达蛋白.运用双向凝胶电泳以及基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS/MS)分析鉴定出高畸形率和正常的水牛精子的差异表达蛋白,并对部分蛋白进行生物信息学分析.结果显示,高畸形率和正常水牛精子之间存在16个表达差异明显的蛋白点,与正常水牛精子相比,5个蛋白斑点表达量上调,6个蛋白斑点下调,3个蛋白斑点缺失,2个蛋白斑点在畸形率高的水牛精子特有.质谱鉴定16个差异蛋白,成功鉴定出6个差异蛋白斑点,对应4种蛋白:左旋天冬酰胺酶、热应激蛋白β-9、半乳糖激酶、β-微管蛋白-2C.研究表明,高畸形率和正常水牛精子蛋白质表达存在一定的差异.     

应激心肌损伤的蛋白质组学研究

目的:寻找应激心肌损伤相关蛋白.方法:建立束缚应激心肌损伤模型,制备心室肌2DE蛋白样品和心肌2DE图谱,图像分析软件分析应激后蛋白表达差异点,MALDI-TOF-MS-数据库搜索鉴定蛋白质.结果:应激前后10个蛋白表达量发生改变,其中8个应激后表达显著升高,经质谱鉴定为心肌肌球蛋白、白蛋白、脂蛋白A-I前体等;2个显著降低,经质谱鉴定为线粒体能量代谢酶类和UCP3.结论:这些差异蛋白可能参与应激机体心肌损伤的发生.     

胆管癌患者与健康志愿者血清样品蛋白质表达差异分析

胆管癌（cholangiocarcinoma,CCA）是一种难于早期诊断和治疗的恶性肿瘤.利用蛋白质组学技术以期筛选出人血清中具有医学价值的胆管癌癌变的标志物.利用白蛋白/IgG去除试剂盒去除血清中高丰度的白蛋白和IgG,再经丙酮沉淀得到高质量的血清样品.样品经双向电泳（2-DE）得到了分辨率较好的胆管癌血清的蛋白点图谱.利用Image Master 2D软件对比分析了胆管癌病人和正常健康对照组的2-DE图谱.其中,表达上调蛋白有8个,表达下调蛋白有6个.用质谱获得上述差异蛋白的肽质量指纹图谱,并经数据库检索共鉴定出了11种差 异蛋白质,其中8种蛋白质的表达与胆管癌密切相关.本研究为阐明胆管癌的机理提供了一条新途径.     

肾阳虚证候的人血清比较蛋白质组学分析

利用双向电泳（2-DE）优化分离了除去高丰度蛋白（白蛋白和IgG）的老年体虚肾阳虚患者（以健康组为参照）的血清样本,对比分析pH 4～7范围的2-DE谱图,肾阳虚患者和参照组的平均蛋白点分别为(393±32)和(455±19)个. 其中肾阳虚证候表达量上调2倍（P<0.05）以上的蛋白点有26个,下调2倍以上的有33个. 用质谱获得上述差异蛋白的肽质量指纹图谱,并经数据库检索共鉴定出了49种差异蛋白质,其中有10种在肾阳虚血清中特异表达,有6种在健康组血清中特异表达. 蛋白功能分析发现,其中33种蛋白质的差异表达与肾阳虚证密切相关. 蛋白质TCRβ及transthyretin的蛋白印迹实验验证了2-DE 的结果. 该研究结果为阐明中医肾阳虚证的机理提供了一条新途径.     

番茄幼苗盐胁迫响应蛋白质组分析

采用营养液栽培,以盐敏感型番茄品种M82为试材,利用双向电泳(2-DE)研究盐胁迫处理下幼苗叶片蛋白质的表达谱,并采用基质辅助激光解析飞行时间串联质谱(MALDI-TOF/TOF-MS)技术进行差异蛋白质的分离及质谱鉴定。结果表明:(1)盐胁迫处理下,利用2-DE获得差异显著蛋白点20个,其中17个蛋白质点丰度上调表达,3个蛋白质点丰度下调表达。(2)通过质谱分析和蛋白质NCBInr数据库检索,共鉴定出19个差异蛋白,分别为果糖-二磷酸醛缩酶、S-腺苷甲硫氨酸合成酶、甘油醛-3-磷酸脱氢酶等及3个功能未知蛋白;这些鉴定出的差异蛋白质与能量代谢、光合作用、蛋白合成、氧化还原平衡等过程相关,暗示所分离鉴定的蛋白可能参与了番茄的盐胁迫响应,为进一步研究番茄抗逆机制奠定基础。     

脊髓蛋白激酶Cα和γ亚型在吗啡依赖和戒断反应中的不同作用

在大鼠吗啡依赖和戒断模型上,采用行为学、免疫组织化学和Western blot方法观察鞘内应用蛋白激酶C(protien kinase C,PKC)抑制剂chelerythrine chloride(CHE)对吗啡依赖大鼠纳洛酮催促成断反应、脊髓Fos蛋白表达和脊髓神经元胞膜和胞浆PKCα、γ表达的影响,以探讨不同亚型PKC在吗啡依赖和戒断反应中的作用。结果表明,鞘内注射CHE能明显减轻吗啡成断症状的评分和吗啡戒断引起的痛觉异常,抑制吗啡成断期间脊髓Fos蛋白表达的增加;吗啡依赖可引起脊髓神经元PKCα和γ表达的上调和转位：吗啡戒断期间存在明显的且可被鞘内注射CHE抑制的PKCα转位,但未观察到明显的PKCγ转位。上述结果表明,脊髓PKC表达上调和转何可能参与吗啡依赖的形成和戒断反应的表达,且PKCα和γ亚型在吗啡依赖和戒断反应中的作用存在差异。     

青年和老年人结肠上皮的比较蛋白质组学研究

衰老的大肠上皮不仅多种生理功能下降,而且对大肠癌在内的多种衰老相关的肠道疾病易感性显著增加,但结肠上皮衰老及衰老的结肠上皮对癌症易感的分子机制仍然不清楚.为此,应用双向凝胶电泳(2-DE)技术分离青年人及老年人的正常结肠上皮的总蛋白质,图像分析识别差异表达的蛋白质点,基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)对差异表达的蛋白质点进行鉴定,免疫组化和实时定量(real-timequantitative)PCR检测部分差异蛋白,在青年人和老年人结肠上皮中的表达水平.得到了分辨率较高、重复性较好的青年人和老年人结肠上皮的2-DE图谱,质谱分析鉴定了17个结肠上皮衰老相关的蛋白质,免疫组化和real-timequantitativeRT-PCR证实了部分差异蛋白质的表达水平.研究结果提示,线粒体功能受伤、抗氧化能力下降是结肠上皮衰老的重要原因,4个差异蛋白质即guaninenucleotide-bindingproteinbetasubunit-likeprotein(Rack1)、stress-70protein、40SribosomalproteinSA和chlorideintracellularchannelprotein1可能与衰老的结肠上皮对癌症易感有关.     

同时放化疗敏感性不同宫颈癌组织的二维电泳图谱建立及质谱分析

目的:分析同时放化疗后高敏感和低敏感中晚期宫颈癌组织之间蛋白质组的差异,为确定宫颈癌同时放化疗敏感性相关蛋白提供依据。方法:收集治疗前的中晚期宫颈癌活检组织标本,均为中分化鳞癌,置于—80℃超低温冰箱保存。同时放化疗后,根据WHO实体瘤疗效判断标准,将收集的10例宫颈癌组织标本分为高敏感组(5例)和低敏感组(5例);提取组织总蛋白,进行双向凝胶电泳(two-dimensional gel electrophoresis,2-DE)得到凝胶图谱,采用PD-quest 7.0软件进行匹配和差异分析,识别两组之间表达差异蛋白点。将部分差异蛋白点进行胶内原位酶解后进行MALDI-TOF-MS分析,获取肽质量指纹图,数据库搜索鉴定蛋白质。结果:建立了分辨率高,重复性好的同时放化疗后宫颈癌组织高敏感组和低敏感组的双向凝胶电泳图谱。高敏感组蛋白点数为781±74个,低敏感组蛋白点数为766±52个,组间平均匹配率为87.6%。质谱分析成功鉴定15个差异表达蛋白,其中7个蛋白质在高敏感组高表达,8个蛋白质在高敏感组低表达。结论:蛋白质2-DE图谱和质谱鉴定结果说明同时放化疗后高敏感组和低敏感组宫颈癌组织间存在蛋白质表达的差异,这些蛋白质可能与同时放化疗敏感性有关。     

Redox Regulation of Arabidopsis Mitochondrial Citrate Synthase

Citrate synthase has a key role in the tricarboxylic （TCA） cycle of mitochondria of all organisms, as it cata- lyzes the first committed step which is the fusion of a carbon-carbon bond between oxaloacetate and acetyl CoA. The regulation of TCA cycle function is especially important in plants, since mitochondrial activities have to be coordinated with photosynthesis. The posttranslational regulation of TCA cycle activity in plants is thus far almost entirely unexplored. Although several TCA cycle enzymes have been identified as thioredoxin targets in vitro, the existence of any thioredoxin-dependent regulation as known for the Calvin cycle, yet remains to be demonstrated. Here we have investigated the redox regulation of the Arabidopsis citrate synthase enzyme by site-directed mutagenesis of its six cysteine residues. Our results indicate that oxidation inhibits the enzyme activity by the formation of mixed disulfides, as the partially oxidized citrate synthase enzyme forms large redox-dependent aggregates. Furthermore, we were able to demonstrate that thioredoxin can cleave diverse intraas well as intermolecular disulfide bridges, which strongly enhances the activity of the enzyme. Activity measurements with the cysteine variants of the enzyme revealed important cysteine residues affecting total enzyme activity as well as the redox sensitivity of the enzyme.     

Cell Wall,Cytoskeleton, and Cell Expansion in Higher Plants

To accommodate two seemingly contradictory biological roles in plant physiology, providing both the rigid structural support of plant cells and the adjustable elasticity needed for cell expansion, the composition of the plant cell wall has evolved to become an intricate network of cellulosic, hemicellulosic, and pectic polysaccharides and protein. Due to its complexity, many aspects of the cell wall influence plant cell expansion, and many new and insightful observations and technologies are forthcoming. The biosynthesis of cell wall polymers and the roles of the variety of proteins involved in polysaccharide synthesis continue to be characterized. The interactions within the cell wall polymer network and the modification of these interactions provide insight into how the plant cell wall provides its dual function. The complex cell wall architecture is controlled and organized in part by the dynamic intracellular cytoskeleton and by diverse trafficking pathways of the cell wall polymers and cell wall-related machinery. Meanwhile, the cell wall is continually influenced by hormonal and integrity sensing stimuli that are perceived by the cell. These many processes cooperate to construct, maintain, and manipulate the intricate plant cell wall--an essential structure for the sustaining of the plant stature, growth, and life.     

Organelle pH in the Arabidopsis Endomembrane System

The pH of intracellular compartments is essential for the viability of cells. Despite its relevance, little is known about the pH of these compartments. To measure pH in vivo, we have first generated two pH sensors by combining the improved-solubility feature of solubility-modified green fluorescent protein （GFP） （smGFP） with the pH-sensing capabil- ity of the pHluorins and codon optimized for expression in Arabidopsis. PEpHluorin （plant-solubility-modified ecliptic pHluorin） gradually loses fluorescence as pH is lowered with fluorescence vanishing at pH 6.2 and PRpHluorin （plant- solubility-modified ratiomatric pHluorin）, a dual-excitation sensor, allowing for precise measurements. Compartment- specific sensors were generated by further fusing specific sorting signals to PEpHluorin and PRpHluorin. Our results show that the pH of cytosol and nucleus is similar （pH 7.3 and 7.2）, while peroxisomes, mitochondrial matrix, and plastidial stroma have alkaline pH. Compartments of the secretory pathway reveal a gradual acidification, spanning from pH 7.1 in the endoplasmic reticulum （ER） to pH 5.2 in the vacuole. Surprisingly, pH in the trans-Golgi network （TGN） and mul- tivesicular body （MVB） is, with pH 6.3 and 6.2, quite similar. The inhibition of vacuolar-type H＋-ATPase （V-ATPase） with concanamycin A （ConcA） caused drastic increase in pH in TGN and vacuole. Overall, the PEpHluorin and PRpHluorin are excellent pH sensors for visualization and quantification of pH in vivo, respectively.     

How does the host-specialized aphid deal with food deficiency？

Aphis gossypii Glover shows obvious host specialization, with cucurbit- and cotton-specialized biotypes or host races in many regions. Because its annual natal hostcrops senesce earlier the cucurbit-specialized biotype may suffer food deficiency. The method this biotype uses to overcome this challenge is still poorly understood. In orderto understand the potential of the cucurbit-specialized biotype aphids in host shift and usage, the performance of this biotype on cotton （Gossypium hirsutum）, a common butpoor quality host plant, was explored in this study. The cucurbit-specialized aphids could establish populations on cotton only when these plants had at least nine leaves, and subsequent populations developed rather slowly. The presence of whitefly populations on cotton improved the success rate of cucurbit-specialized aphids. The cucurbit-specialized aphidswere mainly distributed on the older leaves of cotton, with only a few settling on the upper leaves. The cucurbit-specialized aphids reared on cotton for 40, 54 and 61 days stillmaintained strong preference for their natal host plant, cucumber （Cucumis sativus）, rather than cotton, and their net reproductive rates and intrinsic rates of natural increase weredramatically lower when they were transferred onto new six-leaf cotton plants or detached leaves. Therefore, we concluded that the cucurbit-specialized aphids have the potentialto utilize mature or whitefly-stressed cotton plants, but that this feeding experience on cotton did not alter their specialization for cucurbits. Some cotton plants could act as atemporary host for the cucurbit-specialized aphids to overcome food deficiency arising from senescing cucurbits.     

Dissecting the Heat Stress Response in Chlamydomonas by Pharmaceutical and RNAi Approaches Reveals Conserved and Novel Aspects

To study how conserved fundamental concepts of the heat stress response （HSR） are in photosynthetic eukaryotes, we applied pharmaceutical and antisense/amiRNA approaches to the unicellular green alga Chlamydomonas reinhardtii. The Chlamydomonas HSR appears to be triggered by the accumulation of unfolded proteins, as it was induced at ambient temperatures by feeding cells with the arginine analog canavanine. The protein kinase inhibitor staurosporine strongly retarded the HSR, demonstrating the importance of phosphorylation during activation of the HSR also in Chlamydomonas. While the removal of extracellular calcium by the application of EGTA and BAPTA inhibited the HSR in moss and higher plants, only the addition of BAPTA, but not of EGTA, retarded the HSR and impaired thermotoler- ance in Chlamydomonas. The addition of cycloheximide, an inhibitor of cytosolic protein synthesis, abolished the attenu- ation of the HSR, indicating that protein synthesis is necessary to restore proteostasis. HSP90 inhibitors induced a stress response when added at ambient conditions and retarded attenuation of the HSR at elevated temperatures. In addition, we detected a direct physical interaction between cytosolic HSP90A/HSP70A and heat shock factor 1, but surprisingly this interaction persisted after the onset of stress. Finally, the expression of antisense constructs targeting chloroplast HSP70B resulted in a delay of the cell＇s entire HSR, thus suggesting the existence of a retrograde stress signaling cascade that is desensitized in HSP7OB-antisense strains.     

Plastid Signals and the Bundle Sheath： Mesophyll Development in Reticulate Mutants

The development of a plant leaf is a meticulously orchestrated sequence of events producing a complex organ comprising diverse cell types. The reticulate class of leaf variegation mutants displays contrasting pigmentation between veins and interveinal regions due to specific aberrations in the development of mesophyll cells. Thus, the reticulate mutants offer a potent tool to investigate cell-type-specific developmental processes. The discovery that most mutants are affected in plastid-localized, metabolic pathways that are strongly expressed in vasculature-associated tis- sues implicates a crucial role for the bundle sheath and their chloroplasts in proper development of the mesophyll cells. Here, we review the reticulate mutants and their phenotypic characteristics, with a focus on those in Arabidopsis thali- ana. Two alternative models have been put forward to explain the relationship between plastid metabolism and meso- phyll cell development, which we call here the supply and the signaling hypotheses. We critically assess these proposed models and discuss their implications for leaf development and bundle sheath function in C3 species. The characteriza- tion of the reticulate mutants supports the significance of plastid retrograde signaling in cell development and highlights the significance of the bundle sheath in C3 photosynthesis.     

Aphis （Hemiptera： Aphididae） species groups found in the Midwestern United States and their contribution to the phylogenetic knowledge of the genus

A phylogeny of the genus Aphis Linnaeus, 1 758 was built primarily from specimens collected in the Midwest of the United States. A data matrix was constructedwith 68 species and 41 morphological characters with respective character states of alate and apterous viviparous females. Dendrogram topologies of analyses performed usingUPGMA （Unweighted Pair Group Method with Arithmetic Mean）, Maximum Parsimony and Bayesian analysis of Cytochrome Oxidase I, Elongation Factor 1-α and primary endosymbiont Buchnera aphidicola 16S sequences were not congruent. Bayesian analysis strongly supported most terminal nodes of the phylogenetic trees. The phylogeny wasstrongly supported by EFI-α, and analysis of COl and EFI-α molecular data combined with morphological characters. It was not supported by single analysis of COI or Buch-hera aphidicola 16S. Results from the Bayesian phylogeny show 4 main species groups： asclepiadis,fabae, gossypii, and middletonii. Results place Aphis and species of the generaProtaphis Bōrner, 1952, Toxoptera Koch, 1856 and Xerobion Nevsky, 1928 in a monophyletic clade. Morphological characters support this monophyly as well. The phylogenyshows that the monophyletic clade of the North American middletonii species group belong to the genus Protaphis： P. debilicornis （Gillette ＆ Palmer, 1929）, comb. nov., P. echinaceae（Lagos and Voegtlin, 2009）, comb. nov., and P. middletonii （Thomas, 1879）. The genus Toxoptera should be considered a subgenus of Aphis （stat. nov.）. The analysis also indicatesthat the current genus Iowana Frison, 1954 should be considered a subgenus of Aphis （stat. nov.）.     

A New Set of Reversibly Photoswitchable Fluorescent Proteins for Use in Transgenic Plants

Fluorescent reporter proteins that allow repeated switching between a fluorescent and a non-fluorescent state in response to specific wavelengths of light are novel tools for monitoring of protein trafficking and super-resolu- tion fluorescence microscopy in living organisms. Here, we describe variants of the reversibly photoswitchable fluores- cent proteins rsFastLime, bsDronpa, and Padron that have been codon-optimized for the use in transgenic Arabidopsis plants. The synthetic proteins, designated rsFastLIME-s, bsDRONPA-s, and PADRON C-s, showed photophysical properties and switching behavior comparable to those reported for the original proteins. By combining the ＇positively switchable＇ PADRON C-s with the ＇negatively switchable＇ rsFastLIME-s or bsDRONPA-s, two different fluorescent reporter proteins could be imaged at the same wavelength upon transient expression in Nicotiana benthamiana cells. Thus, co-localiza- tion analysis can be performed using only a single detection channel. Furthermore, the proteins were used to tag the RNA-binding protein AtGRP7 （Arabidopsis thaliana glycine-rich RNA-binding protein 7） in transgenic Arabidopsis plants. Because the new reversibly photoswitchable fluorescent proteins show an increase in signal strength during each pho- toactivation cycle, we were able to generate a large number of scans of the same region and reconstruct 3-D images of AtGRP7 expression in the root tip. Upon photoactivation of the AtGRP7：rsFastLIME-s fusion protein in a defined region of a transgenic Arabidopsis root, spreading of the fluorescence signal into adjacent regions was observed, indicating that movement from cell to cell can be monitored. Our results demonstrate that rsFastLIME-s, bsDRONPA-s, and PADRON C-s are versatile fluorescent markers in plants, Furthermore, the proteins also show strong fluorescence in mammalian cells including COS-7 and HeLa cells.     

Heteromeric and Homomeric Geranyl Diphosphate Synthases from Catharanthus roseus and Their Role in Monoterpene Indole Alkaloid Biosynthesis

Catharanthus roseus is the sole source of two most important monoterpene indole alkaloid （MIA） anti- cancer agents： vinblastine and vincristine. MIAs possess a terpene and an indole moiety derived from terpenoid and shikimate pathways, respectively. Geranyl diphosphate （GPP）, the entry point to the formation of terpene moiety, is a product of the condensation of isopentenyl diphosphate （IPP） and dimethylallyl diphosphate （DMAPP） by GPP synthase （GPPS）. Here, we report three genes encoding proteins with sequence similarity to large subunit （CrGPPS.LSU） and small subunit （CrGPPS.SSU） of heteromeric GPPSs, and a homomeric GPPSs. CrGPPS.LSU is a bifunctional enzyme producing both GPP and geranyl geranyl diphosphate （GGPP）, CrGPPS.SSU is inactive, whereas CrGPPS is a homomeric enzyme forming GPP. Co-expression of both subunits in Escherichia coil resulted in heteromeric enzyme with enhanced activity producing only GPR While CrGPPS.LSU and CrGPPS showed higher expression in older and younger leaves, respectively, CrGPPS.SSU showed an increasing trend and decreased gradually. Methyl jasmonate （MelA） treatment of leaves sig- nificantly induced the expression of only CrGPPS.SSU. GFP localization indicated that CrGPPS.SSU is plastidial whereas CrGPPS is mitochondrial. Transient overexpression of AmGPPS.SSU in C. roseus leaves resulted in increased vindoline, immediate monomeric precursor of vinblastine and vincristine. Although C. roseus has both heteromeric and homomeric GPPS enzymes, our results implicate the involvement of only heteromeric GPPS with CrGPPS.SSU regulating the GPP flux for MIA biosynthesis.