共查询到11条相似文献,搜索用时 0 毫秒
1.
大鼠2/3肝切除模型为研究肝细胞增殖和生理性血管生成提供了一个很好的活体内模型.为了揭示肝再生过程中与肝细胞增殖终止相关及与血管生成启动相关的质膜蛋白质,本研究对大鼠肝2/3部分切除72 h后的肝脏质膜进行了研究:利用两步蔗糖密度梯度离心法对切除组和假手术组的肝脏质膜进行纯化;然后通过双向电泳和质谱技术对肝切除样品进行了比较分析并对几个关键蛋白程序性凋亡相关蛋白-6和丝蛋白-A进行了免疫印迹验证.相对于假手术对照组(Sham组),21种蛋白质在切除后72 h的肝脏中上调,15种蛋白质下调.所鉴定的差异表达蛋白参与了血管生成、细胞分裂增殖和凋亡、细胞分化调控、肝脏组织重新构建、代谢及应急反应.本研究为肝脏再生及其血管生成的研究提供了理论依据. 相似文献
2.
Proteomic analysis of parkin knockout mice: alterations in energy metabolism, protein handling and synaptic function 总被引:8,自引:0,他引:8
Parkin knockout (KO) mice show behavioural and biochemical changes that reproduce some of the presymptomatic aspects of Parkinson's disease, in the absence of neuronal degeneration. To provide insight into the pathogenic mechanisms underlying the preclinical stages of parkin-related parkinsonism, we searched for possible changes in the brain proteome of parkin KO mice by means of fluorescence two-dimensional difference gel electrophoresis and mass spectrometry. We identified 87 proteins that differed in abundance between wild-type and parkin KO mice by at least 45%. A high proportion of these proteins were related to energy metabolism. The levels of several proteins involved in detoxification, stress-related chaperones and components of the ubiquitin-proteasome pathway were also altered. These differences might reflect adaptive mechanisms aimed at compensating for the presence of reactive oxygen species and the accumulation of damaged proteins in parkin KO mice. Furthermore, the up-regulation of several members of the membrane-associated guanylate kinase family of synaptic scaffold proteins and several septins, including the Parkin substrate cell division control related protein 1 (CDCRel-1), may contribute to the abnormalities in neurotransmitter release previously observed in parkin KO mice. This study provides clues into possible compensatory mechanisms that protect dopaminergic neurones from death in parkin KO mice and may help us understand the preclinical deficits observed in parkin-related parkinsonism. 相似文献
3.
《Marine and Freshwater Behaviour and Physiology》2007,40(3):189-194
Chemical communication may play a major role in aquatic environments because of visibility limitations, but when turbidity is reduced do chemical and visual stimuli interact to elicit food-search behaviour by Procambarus clarkii? Does P. clarkii use visual cues to detect its prey? We conducted behavioural experiments in a Y maze, under non-turbid conditions. In the experiments P. clarkii was exposed to chemical plus visual (CV) and visual only (V) stimuli transmitted by Chironomus riparius. The results revealed that P. clarkii detected CV and V cues associated with the presence of C. riparius. In controls, with no prey, crayfish displayed only searching behaviour, whereas in treatments they exhibited searching, detection and attack behaviours. Further, there were no significant differences between CV and V stimuli in the mean number of attacks performed by crayfish. Thus, our findings indicate that under low turbidity, visual cues are sufficient to mediate prey detection by P. clarkii. 相似文献
4.
The bean bug, Riptortus pedestris (Hemiptera: Alydidae) is a polyphagous insect pest and has a wide range of hosts including leguminous plants and tree fruits. Currently, the management of R. pedestris mainly relies on the use of insecticides, and most studies have focused on the lethal effects of insecticides. However, insecticides can not only kill insects directly, but can also affect behavioral changes of survivors when exposed to sub-lethal doses. In this study, we investigated locomotory behaviors (vertical movement, horizontal movement, and flight ability) and feeding behaviors (frequency of insects approaching dried soybean seeds and number of stylet sheaths left on the dried soybean seeds by insects) of surviving R. pedestris pre-exposed to five insecticide residues for 4 h. None of the three insecticides (bifenthrin, etofenprox, and acetamiprid) tested had significant effects on the locomotory behaviors of R. pedestris adults compared to the water-treated control group. Fenitrothion- and dinotefuran-treated groups showed a significant decrease in the vertical movement compared to the water-treated control, but the insects recovered mobility 24 h after the initial exposure. The frequency of R. pedestris approaching to dried soybean seeds was affected by four insecticides (fenitrothion, etofenprox, bifenthrin, and dinotefuran), but the actual feeding activity of R. pedestris determined by the stylet sheaths remaining on the dried soybean seed was only affected by fenitrothion treatment. Given the relatively low toxic effects of five insecticides tested, a better understanding of the impact of insecticides on the behavior of target species is needed for a more robust pest control strategy and a more effective use of insecticides in IPM programs. 相似文献
5.
T. Kashiwagi V. B. Meyer-Rochow K. Nishimura E. Eguchi 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1997,167(1):1-8
The ultrastructural state of the crayfish visual membrane is correlated with its fatty acid composition during times of photic
and thermal stress and the period over which the dynamic events occur is investigated. Crayfish kept at 4 °C under constant
darkness contain in their rhabdoms significantly increased amounts of unsaturated fatty acids such as 16:1, 18:1, 20:5, and
22:6 compared with individuals kept at 25 °C. The ratio of unsaturated/saturated fatty acids (UFA/SFA-ratio) amounts to 2.17
in the cold-water- and 1.46 in the warm water-acclimated animals. The visual membranes of crayfish suddenly transferred from
4 °C to 25 °C exhibited ultrastructural modifications such as membrane collapse and disappearance of microvillar dense␣core-filaments
most clearly 3 h post-transfer. Parallel to the structural changes a significant increase in fatty acid 18:0 was observed,
while the amounts of 16:1 and 20:1 decreased. When 4 °C, dark-adapted crayfish were exposed to light alone and not a temperature
increase, only fatty acid 22:6 showed a significant reduction to 10% of its pre-experimental level within 2 h of exposure.
Thereafter, it slowly increased again. In cold water-acclimated crayfish that had been exposed to light of 5000 lx for 3␣weeks
no significant change of the UFA/SFA ratio was observed, although fatty acid species 18:0, 20:4, and 20:5 had increased at
the expense of fatty acids 14:0, 16:0, 16:1, 18:1, 20:1, and 22:6. The total amount of fatty acids, however, had become significantly
smaller (from 0.058 ng g−1 body weight in the dark-adapted to 0.048 ng g−1 in the light-adapted crayfish). Morphologically the rhabdom volume had decreased by approx. 20%, but ultrastructurally rhabdom
microvilli remained almost unchanged. The amount of peroxidized lipids in the retina following irradiation with bright white
light in the cold-adapted crayfish fell during the first 2 h of exposure from 0.4 nmol g−1 to 0.32 nmol g−1, but after 12 h of exposure had reached a level of 0.48 nmol g−1. Greatest structural abnormalities to the visual membranes occurred when dark-adapted, cold-acclimated crayfish were suddenly
subjected to bright light and an increase in water temperature. Under such conditions the microvillar arrangement was disrupted
and membrane collapse and disappearance of core-filaments were apparent. Our results provide evidence that the fatty acid
composition of the membranes determines to a considerable extent the structural integrity of the photoreceptor, but that it
is too simplistic a model to think that peroxidation of membrane lipids alone is responsible for the disintegration of the
photoreceptive membranes in the crayfish eye following exposure to bright light.
Accepted: 4 July 1996 相似文献
6.
Nonomuraea sp. ATCC 39727 is an aerobic actinomycete, industrially important as a producer of the glycopeptide A40926, which is used as a precursor of the semi-synthetic antibiotic dalbavancin. Previous studies showed that the production of A40926 is depressed by calcium, but promoted by l-glutamine or l-asparagine. In this study, the protein expression changes of Nonomuraea sp. ATCC 39727 in these two different growth and antibiotic-production conditions have been investigated by two-dimensional electrophoresis and mass spectrometry (MS) analysis. Few protein spots show statistically significant expression changes, and, among this group of proteins, malate dehydrogenase (MDH) shows a significant decrease in the overproduction condition. The decrease of MDH is of particular interest because it is the first described significant change in the expression levels of enzymes of the central metabolism related with A40926 overproduction. 相似文献
7.
AbstractThe acute zebra fish embryo test (Danio rerio Hamilton–Buchanan, 1822) is an accepted bioassay to assess the toxicity of waste water that may be used for the replacement of testing with adult fish. It is also suggested for chemical hazard characterization and assessment, although only a few groups of substances have yet been studied. Specifically acting substances such as neurotoxic insecticides pose a potentially hazard for non-target fish. To establish whether the proposed zebra fish embryo test protocol and the inhibition of cholinesterases (acetylcholinesterase EC 3.1.1.7, propionylcholinesterase EC 3.1.1.8) and carboxylesterase (EC 3.1.1.1) enzymes can be used in a similar fashion for hazard characterization and risk assessment of chemicals and environmental samples, two types of experiments were conducted. Visual effects of exposure to the organophosphate metabolite paraoxon-methyl after 24 and 48 h in the zebra fish embryo test system were analysed with the use of an inverse microscope (rate of mortality, developmental disturbances, heart rate and others). The inhibition to cholinesterases and carboxylesterase was also measured. Enzyme inhibition as a biomarker of exposure was about 70 times more sensitive than the effects in the zebra fish embryo test with an IC50 below 1.2?µmol compared with an EC50 of 91?µmol. The dose–response relationships showed different curve characteristics with a linear increase of enzyme inhibition compared with a sigmoidal curve for the overt effects. Significant overt effects could only be seen at concentrations at which already 80% of the activities of the different esterases were inhibited. 相似文献
8.
The acute zebra fish embryo test (Danio rerio Hamilton-Buchanan, 1822) is an accepted bioassay to assess the toxicity of waste water that may be used for the replacement of testing with adult fish. It is also suggested for chemical hazard characterization and assessment, although only a few groups of substances have yet been studied. Specifically acting substances such as neurotoxic insecticides pose a potentially hazard for non-target fish. To establish whether the proposed zebra fish embryo test protocol and the inhibition of cholinesterases (acetylcholinesterase EC 3.1.1.7, propionylcholinesterase EC 3.1.1.8) and carboxylesterase (EC 3.1.1.1) enzymes can be used in a similar fashion for hazard characterization and risk assessment of chemicals and environmental samples, two types of experiments were conducted. Visual effects of exposure to the organophosphate metabolite paraoxon-methyl after 24 and 48 h in the zebra fish embryo test system were analysed with the use of an inverse microscope (rate of mortality, developmental disturbances, heart rate and others). The inhibition to cholinesterases and carboxylesterase was also measured. Enzyme inhibition as a biomarker of exposure was about 70 times more sensitive than the effects in the zebra fish embryo test with an IC50 below 1.2 µmol compared with an EC50 of 91 µmol. The dose-response relationships showed different curve characteristics with a linear increase of enzyme inhibition compared with a sigmoidal curve for the overt effects. Significant overt effects could only be seen at concentrations at which already 80% of the activities of the different esterases were inhibited. 相似文献
9.
J.R. Brock G.K. Bielmyer 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2013,158(3):150-158
The marine environment is subjected to contamination by a complex mixture of metals from various anthropogenic sources. Measuring the biological responses of organisms to a complex mixture of metals allows for examination of metal-specific responses in an environmentally realistic exposure scenario. To address this issue, the sea anemone, Aiptasia pallida was exposed to a control and a metal mixture (copper, zinc, nickel, and cadmium) at three exposure levels (10, 50, and 100 μg/L) for 7 days. Anemones were then transferred to metal-free seawater for an additional 7 days after the metal exposure to assess metal depuration and recovery. Metal accumulation, activity of the enzymes catalase, glutathione reductase, and carbonic anhydrase, as well as, cell density of the symbiotic zooxanthellae were measured over 14 days. Metal accumulation in A. pallida occurred in a concentration dependent manner over the 7-day exposure period. Altered enzyme activity and tentacle retraction of the host, as well as decreased zooxanthellae cell density were observed responses over the 7 days, after exposure to a metal concentration as low as 10 μg/L. Metal depuration and physiological recovery were dependent on both the metal and the exposure concentration. Understanding how A. pallida and their symbionts are affected by metal exposures in the laboratory may allow better understanding about the responses of symbiotic cnidarians in metal polluted aquatic environments. 相似文献
10.
A proteomic approach was used to identify proteins involved in post-flooding recovery in soybean roots. Two-day-old soybean seedlings were flooded with water for up to 3 days. After the flooding treatment, seedlings were grown until 7 days after sowing and root proteins were then extracted and separated using two-dimensional polyacrylamide gel electrophoresis (2-DE). Comparative analysis of 2-D gels of control and 3 day flooding-experienced soybean root samples revealed 70 differentially expressed protein spots, from which 80 proteins were identified. Many of the differentially expressed proteins are involved in protein destination/storage and metabolic processes. Clustering analysis based on the expression profiles of the 70 differentially expressed protein spots revealed that 3 days of flooding causes significant changes in protein expression, even during post-flooding recovery. Three days of flooding resulted in downregulation of ion transport-related proteins and upregulation of proteins involved in cytoskeletal reorganization, cell expansion, and programmed cell death. Furthermore, 7 proteins involved in cell wall modification and S-adenosylmethionine synthesis were identified in roots from seedlings recovering from 1 day of flooding. These results suggest that alteration of cell structure through changes in cell wall metabolism and cytoskeletal organization may be involved in post-flooding recovery processes in soybean seedlings. 相似文献
11.
James A. Langston Kimberly Brown Feng Xu Kim Borch Ashley Garner Matt D. Sweeney 《Biochimica et Biophysica Acta - Proteins and Proteomics》2012,1824(6):802-812
The enzyme cellobiose dehydrogenase (CDH) is of considerable interest, not only for its biotechnological applications, but also its potential biological role in lignocellulosic biomass breakdown. The enzyme catalyzes the oxidation of cellobiose and other cellodextrins, utilizing a variety of one- and two-electron acceptors, although the electron acceptor employed in nature is still unknown. In this study we show that a CDH is present in the secretome of the thermophilic ascomycete Thielavia terrestris when grown with cellulose, along with a mixture of cellulases and hemicellulases capable of breaking down lignocellulosic biomass. We report the cloning of this T. terrestris CDH gene (cbdA), its recombinant expression in Aspergillus oryzae, and purification and characterization of the T. terrestris CDH protein (TtCDH). The TtCDH shows spectral properties and enzyme activity similar to other characterized CDH enzymes. Substrate specificity was determined for a number of carbohydrate electron donors in the presence of the two-electron acceptor 2,6-dichlorophenol-indophenol. The TtCDH also shows dramatic synergy with Thermoascus aurantiacus glycoside hydrolase family 61A protein in the presence of a β-glucosidase for the cleavage of cellulose. 相似文献