Th17/Treg 细胞在银屑病的发病机制研究进展

Th17细胞和Treg细胞是CD4+T细胞在不同细胞因子环境中分化出的新亚群,发挥不同的生物学效应,使机体的免疫系统处于平衡状态.Th17/Treg细胞失衡可引起一系列自身免疫性疾病.银屑病是与遗传、免疫异常有关的皮肤炎症性疾病,其发病机制尚不清楚.越来越多的研究发现,Th17细胞增多和Treg细胞减少及其分泌的细胞因子在银屑病的发病中有着重要作用.本文围绕这一机制综述了近年来有关Th17细胞、Treg细胞在银屑病发病机制中作用的研究,帮助我们更深入地了解银屑病的发病机制并为今后临床诊断和治疗提供依据.     

Differential accumulation of mRNAs in drought-tolerant and susceptible common bean cultivars in response to water deficit

The physiological response to drought was measured in two common bean varieties with contrastive susceptibility to drought stress. A subtractive cDNA library was constructed from the two cultivars, Phaseolus vulgaris'Pinto Villa' (tolerant) and 'Carioca' (susceptible). 18 cDNAs displayed protein-coding genes associated with drought, cold and oxidative stress, signal transduction, plant defense, chloroplast function and unknown function. A cDNA coding for an aquaporin (AQP) was selected for further analyses. The open reading frames (ORFs) of AQPs from 'Pinto Villa' and 'Carioca' were compared and despite their similarity, accumulated differentially in the plant organs, as demonstrated by Northern blot and in situ hybridization. A phylogenetic analysis of the deduced amino acid sequence with other AQPs suggested a tonoplast-located protein. Under drought conditions, the levels of AQP mRNA from the susceptible cultivar decreased to undetectable levels; by contrast, 'Pinto Villa' mRNA was present and restricted the phloem tissue. This would allow 'Pinto Villa' to maintain vascular tissue functions under drought stress.     

Metabolic activity of plant mitochondria in hypertonic sucrose solutions

This study deals with effects of hypertonic sucrose solutions on respiration and oxidative phosphorylation of intact mitochondria isolated from sugar beet (Beta vulgaris L.) taproots and etiolated pea (Pisum sativum L.) seedlings. Mitochondria from plants, like those of animals, showed a trend to inhibition of oxidative phosphorylation in hypertonic sucrose solutions. The increase in sucrose concentration from 0.5 to 1.0 M suppressed malate oxidation in the presence of glutamate in state 3 by a factor of 2.5–3.5 and diminished the respiratory control ratio by a factor of 1.5–2.0. Plant mitochondria turned out remarkably resistant to osmotic stress; they retained significant respiratory control and high ADP/O ratios in a hypertonic 1 M sucrose solution. Although the origin of the observed phenomenon remains unresolved and warrants further studies, it is evident that elevated resistance of plant mitochondria to osmotic stress might be significant for energy supply under extreme environmental conditions (upon drought and salinity) when the plant organism experiences dehydration with a concomitant increase in the cytoplasmic osmolarity.     

RT-PCR克隆甜菜硝酸还原酶cDNA全长序列及分析

根据GenBank中已公布的甜菜（Beta vulgaris）硝酸还原酶（nitrate reductase）基因序列（gb∣ABW05098.1∣）,设计引物,以50 mmol·L^-1 KNO₃溶液处理的甜菜幼苗为材料,从总RNA中通过RT-PCR分离得到一个硝酸还原酶基因,其cDNA长2 760 bp,包含了完整的基因编码序列,与已公布的硝酸还原酶基因序列相似性达99%。Southern杂交分析表明,硝酸还原酶基因在甜菜基因组中可能以两个拷贝或低拷贝形式存在。根据其编码的氨基酸序列,利用生物信息学预测了其亚细胞定位和蛋白质的三级结构。     

欧报春（Primula vulgaris）不同花色与色素关系及花色遗传初步分析

为了掌握欧报春各花色遗传规律服务于良种生产,通过对欧报春各色花进行色素吸收光谱和薄层层析分析,进行不同花色杂交研究,分析了欧报春各色花所含色素类型及各花色遗传规律。结果显示欧报春群体含多种花色素,单株也可含有多种花色素,形成多变的粉色、红色及蓝色花。黄色深浅主要由类胡萝卜素含量决定。白色对粉色及黄色为隐性遗传,黄色、粉色为显性遗传并有数量遗传特征,黄色与粉色独立遗传。蓝色为多基因控制的隐性遗传,并具有数量遗传特征。     

Molecular cloning, characterization and regulation of two different NADH-glutamate synthase cDNAs in bean nodules

NADH-dependent glutamate synthase (NADH-GOGAT) is a key enzyme in primary ammonia assimilation in Phaseolus vulgaris nodules. Two different types of cDNA clones of PvNADH-GOGAT were isolated from the nodule cDNA libraries. The full-length cDNA clones of PvNADH-GOGAT-I (7.4 kb) and PvNADH-GOGAT-II (7.0 kb), which displayed an 83% homology between them, were isolated using cDNA library screening, 'cDNA library walking' and RT-PCR amplification. Southern analysis employing specific 5' cDNA probes derived from PvNADH-GOGAT-I and PvNADH-GOGAT-II indicated the existence of a single copy of each gene in the bean genome. Both these proteins contain ∼100 amino acid sequences theoretically addressing each isoenzyme to different subcellular compartments. RT-PCR analysis indicated that PvNADH-GOGAT-II expression is higher than PvNADH-GOGAT-I during nodule development. Expression analysis by RT-PCR also revealed that both of these genes are differentially regulated by sucrose. On the other hand, the expression of PvNADH-GOGAT-I , but not PvNADH-GOGAT-II, was inhibited with nitrogen compounds. In situ hybridization and promoter expression analyses demonstrated that the NADH-GOGAT-I and -II genes are differentially expressed in bean root and nodule tissues. In silico analyses of the NADH-GOGAT promoters revealed the presence of potential cis elements in them that could mediate differential tissue-specific, and sugar and amino acid responsive expression of these genes.     

The multicomponent phytopharmaceutical SKI306X inhibits in vitro cartilage degradation and the production of inflammatory mediators

Clinical studies have demonstrated that SKI306X, a purified preparation of three medicinal plants, relieves joint pain and improves functionality in osteoarthritis patients. To study the biological action of SKI306X, bovine cartilage explants and human peripheral blood mononuclear cells (PBMC) were stimulated with IL-1β and lipopolysaccharide (LPS) respectively, in the presence or absence of SKI306X and its individual composites. All tested compounds inhibited dose-dependently IL-1β-induced proteoglycan release and nitric oxide production by cartilage, indicating cartilage protective activity. SKI306X and two of its compounds inhibited PGE₂, TNF- and IL-1β production by LPS-stimulated PBMC, indicating anti-inflammatory activity. These results demonstrate that the biological effect of SKI306X is at least bipartite: (1) cartilage protective and (2) anti-inflammatory. The observed anti-inflammatory effects may provide an explanation for the outcome of the clinical studies. Long-term clinical trails are necessary to elucidate whether the in vitro cartilage protective activity results in disease-modifying effects.     

Growth,photosynthesis, and metabolism of sugar beet at an early stage of exposure to elevated CO<Subscript>2</Subscript>

The effects of CO₂ concentration (C _a) on growth, photosynthesis, and the activity of enzymes associated with the translocation and assimilation of CO₂ were studied in sugar beet (Beta vulgaris L. subsp. saccharifera, cv. Ramonskaya) plants. The plants were grown in controlled-climate chamber to the stage of 3–4 leaves and then used in experiments. Experimental plants were exposed in boxes to doubled C _a (700 µl/l, 2C plants), whereas control plants were kept in a chamber with ambient atmosphere (350 µl/l, 1C plants). As compared with 1C plants, in 3 and 8 days, the leaf area of 2C plants increased by 14 and 26%, respectively. The rate of their photosynthesis (P _n) measured in 3, 6, and 8 days increased by 85, 47, and 52%, respectively, whereas in normal air, the values of P _n in 2C plants were by 12, 19, and 15% lower than in 1C plants. After 8-day growth, the content of soluble carbohydrates in the leaves of 2C plants attained 7.2%, being by 80% greater than in 1C plants; the content of starch did not exceed 3%. The total content of chlorophylls a and b in the leaves of 2C plants was by 14% greater than in 1C plants, but their ratio was essentially the same. The level of protein in 2C plants was by 13.4% lower than in 1C plants. The activity and content of Rubisco in 1C and 2C plants were similar. As compared with 1C plants, in 2C plants the activity of soluble carbonic anhydrase (sCA) was lower by 34% in 3 days and by 18% in 8 days; the activity of carbonic anhydrase of membrane preparations (mCA), was lower by 24 and 77%, respectively. Catalase activity in 2C plants became by 8% lower than in 1C plants only after 8 days. A reduction in the photosynthetic ability of 2C plants in ambient atmosphere, a decrease in activity of sCA and, especially, of mCA observed together with invariable activity and content of Rubisco in the leaf extracts are interpreted as early symptoms of acclimation of young plants of sugar beet to elevated CO₂.Translated from Fiziologiya Rastenii, Vol. 52, No. 2, 2005, pp. 184–190.Original Russian Text Copyright © 2005 by Ignatova, Novichkova, Mudrik, Lyubimov, Ivanov, Romanova.This revised version was published online in April 2005 with a corrected cover date.     

AFLP指纹图谱试验体系在甜菜无融合生殖系中的应用

目的：比较甜菜无融合生殖品系M14子代之间的同一性及亲缘关系,从而验证AFLP试验体系在甜菜无融合生殖系中的适用性。方法：利用已建立的AFLP试验体系,通过琼脂糖凝胶电泳和聚丙烯酰胺凝胶电泳检测以及遗传距离的比较来验证这一试验体系。结果：M14子代之间及二倍体甜菜之间的同一性较好,其亲缘关系也较近。结论：验证了所建立的AFLP试验体系的适用性,同时也确证了AFLP技术在构建DNA指纹图谱中的优越性,为无融合生殖的进一步研究奠定了基础。