维生素E对体外培养的人脐静脉内皮细胞白介素-8表达的影响

目的探讨维生素E(α-生育酚)对人脐静脉内皮细胞(HUVEC)白介素-8(IL-8)表达的影响.方法体外培养HUVEC,将其随机分为正常对照组和实验组,实验组细胞在用激动剂脂多糖(LPS)刺激之前,分别给予0、10、20、30mg/Lα-生育酚,然后在6h、24h、48h三个时段,利用双抗体夹心酶联免疫吸附技术(ELISA)和原位杂交技术(ISH)检测各组细胞IL-8蛋白表达及mRNA表达水平.结果 (1)正常对照组IL-8有基础表达;(2)与正常对照组比较,ELISA和ISH的结果均显示LPS能够明显诱导IL-8高表达:蛋白表达增强约28倍(P<0.01),mRNA表达增强约4.3倍(P<0.01);(3)维生素E能够抑制LPS诱导的IL-8的表达:ELISA结果显示20mg/L-48hα-T处理组作用最强,IL-8蛋白表达减少72.7%(P<0.01);ISH结果显示20mg/L -24hα-T处理组作用最强,IL-8mRNA表达减少73.2%(P<0.01).结论维生素E可显著抑制LPS诱导的HUVEC高表达IL-8,表明维生素E可通过影响对动脉粥样硬化有重要作用的IL-8的表达来发挥其抗动脉粥样硬化作用.     

Genome-wide association study of heading and flowering dates and construction of its prediction equation in Chinese common wheat

Heading date is one of the most important traits in wheat breeding as it affects adaptation and yield potential. A genome-wide association study (GWAS) using the 90 K iSelect SNP genotyping assay indicated that a total of 306 loci were significantly associated with heading and flowering dates in 13 environments in Chinese common wheat from the Yellow and Huai wheat region. Of these, 105 loci were significantly correlated with both heading and flowering dates and were found in clusters on chromosomes 2, 5, 6, and 7. Based on differences in distribution of the vernalization and photoperiod genes among chromosomes, arms, or block regions, 13 novel, environmentally stable genetic loci were associated with heading and flowering dates, including RAC875_c41145_189 on 1DS, RAC875_c50422_299 on 2BL, and RAC875_c48703_148 on 2DS, that accounted for more than 20% phenotypic variance explained (PVE) of the heading/flowering date in at least four environments. GWAS and t test of a combination of SNPs and vernalization and photoperiod alleles indicated that the Vrn-B1, Vrn-D1, and Ppd-D1 genes significantly affect heading and flowering dates in Chinese common wheat. Based on the association of heading and flowering dates with the vernalization and photoperiod alleles at seven loci and three significant SNPs, optimal linear regression equations were established, which show that of the seven loci, the Ppd-D1 gene plays the most important role in modulating heading and flowering dates in Chinese wheat, followed by Vrn-B1 and Vrn-D1. Additionally, three novel genetic loci (RAC875_c41145_189, Excalibur_c60164_137, and RAC875_c50422_299) also show important effect on heading and flowering dates. Therefore, Ppd-D1, Vrn-B1, Vrn-D1, and the novel genetic loci should be further investigated in terms of improving heading and flowering dates in Chinese wheat. Further quantitative analysis of an F₁₀ recombinant inbred lines population identified a major QTL that controls heading and flowering dates within the Ppd-D1 locus with PVEs of 28.4% and 34.0%, respectively; this QTL was also significantly associated with spike length, peduncle length, fertile spikelets number, cold resistance, and tiller number.     

用显微分光光度术测定不同发育时期蚕豆子叶淀粉质体DNA含量

叙述了用显微光度术在亚细胞水平上测量蚕豆子叶细胞中淀粉质体Ｆｅｕｌｇｅｎ－ＤＮＡ含量,显示了在不同发育时期蚕豆子叶细胞中的淀粉体ＤＮＡ含量的动态变化。随着发育时期的递增,淀粉体ＤＮＡ拷贝数不断地增长。生长中期的淀粉体ＤＮＡ含量平均数为２．１４（任意单位）,到了成熟期淀粉体ＤＮＡ平均含量增长到１０．１２（任意单位）。在成熟期,子叶细胞中的淀粉体ＤＮＡ含量比生长中期增长了９．６倍。通过生物统计分析,在     

Epitope Mapping and Identification of Amino Acids Critical for Rabbits IgG-Binding to Linear Epitopes on Buffalo beta-lactoglobulin

Buffalo milk safety was highlighted with the increase in dietary consumption, and a little information is available on buffalo milk allergy except for cross-reactivity between buffalo and cow milk. In this work, linear epitopes and critical amino acids of buffalo β-lactoglobulin were defined by 4 rabbit's sera using SPOTTM peptide arrays approach based on the defined mimotopes. The eight epitopes on buffalo β-lactoglobulin were located in the position of A6(21-30), A7(25-34), A8 (29-38), B4 (73-82), B5(77-86), C(87-96), F4(134-143) and F8(150-159), respectively. Among them, four epitopes (A7, A8, F4 and F8) were described as the most major epitopes and peptide (A6, B4, B5 and C) as the second major epitopes. Following single AA substitutions (Alanine or Glycine) at each position of the major epitopes, 2,3,2,3,5 and 3 of critical amino acids were identified on epitopes of A6, A8, B5, C , F4 and F8, respectively, which vary in distribution among the epitopes, such as in C terminal or N terminal and in continuous or discontinuous forms, characteristics including hydrophobicity, polar and charge, and existed frequency.     

Study on Chromium (VI) Reduction Kinetics by Pseudomonas aeruginosa Using a Combined System of Acoustic Wave Impedance Analyzer and UV-Vis Spectrophotometer

A novel system combining acoustic wave impedance (AWI) analyzer with UV-vis spectrophotometer was developed for the study of chromium (VI) reduction kinetics by Pseudomonas aeruginosa. AWI gave information about the growth of Pseudomonas aeruginosa, and UV-vis spectrophotometer gave information about the concentration of chromium (VI) simultaneously. A combined system response model, for chromium (VI) reduction kinetics at lower initial chromium (VI) concentrations, was derived and proved based on the novel system. Taking into account the effect of bacterial growth on chromium (VI) reduction, the new model successfully simulated chromium (VI) bioremediation process. By fitting chromium (VI) reduction data toward the derived model, the kinetic parameters related to the process were obtained. When the concentration of peptone was 10 g L⁻¹, the half-velocity reduction rate constant K _C and the maximum specific chromium (VI) reduction rate constant ν_max were 0.7682 mg chromium (VI) L⁻¹ and 2.5814 × 10⁻¹² mg chromium (VI) cells⁻¹ h⁻¹, respectively. It was found that the combined system can provide real-time, reliable, and two-dimensional kinetic information, and can be applied to study other biological processes.     

A normal mucin-binding lectin from the sponge Craniella australiensis

A lectin, Craniella australiensis (CAL), was isolated from sponge C. australiensis by ion-exchange on DEAE-Sephacel and purified by gel filtration on Sephadex G-150 and HPLC on DEAE-5PW. The purified lectin was a trimeric protein as revealed by SDS-PAGE and MALDI-TOF analysis. SDS-PAGE showed that the CAL protein had a molecular mass of 54 kDa, and consisted of three 18 kDa subunits. Gel filtration of purified lectin on Sephadex G-200 indicates that it exists as a 54 kDa protein in its native state. The amino acid composition was rich in Thr and Glx. CAL was found to agglutinate native and trypsinized human A, B erythrocytes, and agglutinate native erythrocytes of mouse, sheep, rabbit and chicken, and trypsinized erythrocytes of sheep and rabbit. The hemagglutination activity was inhibited by glycoproteins such as PSM and asialo-PSM, but not by any of the monosaccharides tested. The activity was stable between 20 and 70 degrees C. Significant CAL activity was observed between pH 5 and 8. The lectin reaction is independent of the presence of divalent cations Ca2+ and Mg2+. The sequence of N-terminal residues of CAL was determined as TSSCQSIVVE. The lectin showed a potent mitogenic response towards BALB/c splenocytes.     

Soil Tillage Management Affects Maize Grain Yield by Regulating Spatial Distribution Coordination of Roots,Soil Moisture and Nitrogen Status

The spatial distribution of the root system through the soil profile has an impact on moisture and nutrient uptake by plants, affecting growth and productivity. The spatial distribution of the roots, soil moisture, and fertility are affected by tillage practices. The combination of high soil density and the presence of a soil plow pan typically impede the growth of maize (Zea mays L.).We investigated the spatial distribution coordination of the root system, soil moisture, and N status in response to different soil tillage treatments (NT: no-tillage, RT: rotary-tillage, SS: subsoiling) and the subsequent impact on maize yield, and identify yield-increasing mechanisms and optimal soil tillage management practices. Field experiments were conducted on the Huang-Huai-Hai plain in China during 2011 and 2012. The SS and RT treatments significantly reduced soil bulk density in the top 0–20 cm layer of the soil profile, while SS significantly decreased soil bulk density in the 20–30 cm layer. Soil moisture in the 20–50 cm profile layer was significantly higher for the SS treatment compared to the RT and NT treatment. In the 0-20 cm topsoil layer, the NT treatment had higher soil moisture than the SS and RT treatments. Root length density of the SS treatment was significantly greater than density of the RT and NT treatments, as soil depth increased. Soil moisture was reduced in the soil profile where root concentration was high. SS had greater soil moisture depletion and a more concentration root system than RT and NT in deep soil. Our results suggest that the SS treatment improved the spatial distribution of root density, soil moisture and N states, thereby promoting the absorption of soil moisture and reducing N leaching via the root system in the 20–50 cm layer of the profile. Within the context of the SS treatment, a root architecture densely distributed deep into the soil profile, played a pivotal role in plants’ ability to access nutrients and water. An optimal combination of deeper deployment of roots and resource (water and N) availability was realized where the soil was prone to leaching. The correlation between the depletion of resources and distribution of patchy roots endorsed the SS tillage practice. It resulted in significantly greater post-silking biomass and grain yield compared to the RT and NT treatments, for summer maize on the Huang-Huai-Hai plain.     

Serine Carboxypeptidase SCPEP1 and Cathepsin A Play Complementary Roles in Regulation of Vasoconstriction via Inactivation of Endothelin-1

The potent vasoconstrictor peptides, endothelin 1 (ET-1) and angiotensin II control adaptation of blood vessels to fluctuations of blood pressure. Previously we have shown that the circulating level of ET-1 is regulated through its proteolytic cleavage by secreted serine carboxypeptidase, cathepsin A (CathA). However, genetically-modified mouse expressing catalytically inactive CathA S190A mutant retained about 10–15% of the carboxypeptidase activity against ET-1 in its tissues suggesting a presence of parallel/redundant catabolic pathway(s). In the current work we provide direct evidence that the enzyme, which complements CathA action towards ET-1 is a retinoid-inducible lysosomal serine carboxypeptidase 1 (Scpep1), a CathA homolog with previously unknown biological function. We generated a mouse strain devoid of both CathA and Scpep1 activities (DD mice) and found that in response to high-salt diet and systemic injections of ET-1 these animals showed significantly increased blood pressure as compared to wild type mice or those with single deficiencies of CathA or Scpep1. We also found that the reactivity of mesenteric arteries from DD mice towards ET-1 was significantly higher than that for all other groups of mice. The DD mice had a reduced degradation rate of ET-1 in the blood whereas their cultured arterial vascular smooth muscle cells showed increased ET-1-dependent phosphorylation of myosin light chain 2. Together, our results define the biological role of mammalian serine carboxypeptidase Scpep1 and suggest that Scpep1 and CathA together participate in the control of ET-1 regulation of vascular tone and hemodynamics.