Upregulation of Protein Phosphatase 2A and NR3A-Pleiotropic Effect of Simvastatin on Ischemic Stroke Rats

Ca²⁺ influxes are regulated by the functional state of N-methyl-D-aspartate receptors (NMDARs). Dephosphorylation of NMDARs subunits decreases Ca²⁺ influxes. NR3, a novel subunit of NMDARs, also decreases Ca²⁺ influxes by forming new NMDARs with NR1 and NR2. It is meaningful to uncover whether protein phosphatase 2A (PP2A) and NR3A play a role in the protective effect of Simvastatin on ischemic stroke. In the present study, the Sprague-Dawley rats were pretreated with Simvastatin for 7 days before middle cerebral artery occlusion was performed to mimic ischemic stroke. The results showed that Simvastatin decreased brain ischemic infarct area significantly while increasing the expression levels of PP2A and NR3A, thus dephosphorylating the serine sites of NR1 (ser896 and ser897) along with increased enzymatic activities of PP2A. The protein levels of NR3A decreased as the enzymatic activities of PP2A were inhibited by okadaic acid. The results indicated that Simvastatin could protect the cerebrum from ischemic injury through a signaling mechanism involving elevated levels of PP2A and NR3A, and that PP2A might involve in the regulatory mechanism of NR3A expression.     

In vitro selection of glyphosate-tolerant variants from long-term callus cultures of Zoysia matrella [L.] Merr

A complete protocol of in vitro selection and greenhouse screening for glyphosate-tolerant variants in manilagrass (Zoysia matrella [L.] Merr) was established in this study. Newly subcultured calli of more than 5?years?? old were transferred to selection medium containing 2?mM glyphosate. After two rounds of selection, 220 calli survived out of 840 and were transferred to regeneration medium without glyphosate. Regenerated plantlets were then transferred to regeneration medium containing 0.5?mM glyphosate to select tolerant plantlets. After 1-month growth, there were plantlets remained green and new shoots formed beside or on discolored explants. These surviving organisms were then transferred to fresh regeneration medium for further growth. Fully developed plantlets were transferred to a green house and then subjected to greenhouse screening by foliar spraying with 0.05?% glyphosate solution. Six glyphosate-tolerant plantlets, TP1-TP6, were obtained and proliferated for determination of sod-tolerance using morphological and physiological measurements. Fourteen days after foliar application with 0.1?% glyphosate, only TP5 showed enhanced sod-tolerance. The dark green color index value of TP5 was significantly higher than CK2, demonstrating that TP5 suffered less injury from glyphosate than CK2. Different physiological characters were also observed in CK1, CK2 and TP5. Significantly higher chlorophyll a content and catalase activity were observed in TP5 than in CK1. Fourteen days after treatment (DAT), the ion leakage, proline content and ascorbate peroxidase activity of CK2 and TP5 increased significantly, but the ion leakage of TP5 was significantly lower than that of CK2. The guaiacol peroxidase activity of TP5 increased significantly 14 DAT, and was significantly higher than that of CK1 and CK2. No change in shikimate content was observed in CK2 or TP5 14 DAT.     

拟南芥冷诱导CBF/DREB类结合因子的克隆及其生物信息学分析

CBF/DREB结合因子广泛存在于植物中,主要参与诸如干旱、高盐以及冷胁迫等相关基因的表达调控.以拟南芥DNA为模板,PCR扩增出3个冷诱导的CBF/DREB结合因子,即CBF1、CBF2及CBF3,利用生物信息学手段对三者的cDNA序列、氨基酸序列的相似性、组成成分、理化性质、疏水性/亲水性、功能域、进化树、二级结构及DNA保守域的三级结构等进行了较为全面的分析.结果显示,CBF1、CBF2和CBF3的氨基酸序列同源性很高,达到91.4%,且都属于亲水性蛋白,三者在理化性质以及蛋白质二级结构乃至三级结构上也极为相似.另外, CBF1和CBF2都不具跨膜结构,CBF3含有1个跨膜螺旋.     

Development and evaluation of a trehalose-contained solution formula to preserve hUC-MSCs at 4°C

Human mesenchymal stem cells (hMSCs) hold great promise in cell therapy and regenerative medicine. Various preclinical and clinical trials have been carried out to illustrate the therapeutic potential of these cells. However, one major challenge for manufacturing clinical grade hMSCs is the requisition of current good manufacturing practice (cGMP) grade practices in cell isolation, processing, storage, and distribution. Development of non-toxic and animal serum-free preservation medium is critical for storage and distribution of mesenchymal stem cells (MSCs). In this study, we developed a solution formula that could preserve MSCs at 4°C for up to 3 weeks. In the solution, trehalose is a key ingredient for maintaining survival of MSCs. Among the concentrations investigated, 40 mM trehalose showed the best outcome with the viability maintained more than 92.7 ± 1.5% for 7 days. Cells preserved in the solution formula for 3 weeks still remained about 70% viability, and produced results similar to those of freshly harvested hMSCs in terms of growth kinetics, expression profile of cell surface antigens, and differentiation potential. In summary, storage of MSCs in the medium makes it far easier for transporting the cells from processing units to clinical sites.     

小麦eIF3c基因片段的克隆及序列分析

根据真核翻译起始因子eIF3c的保守序列,搜索小麦EST,由拼接的序列设计引物,从普通小麦‘川麦107'幼苗总RNA中克隆出1102bp的小麦eIF3c1基因片段命名为WeIF3c1.序列分析表明,该片段推断的氨基酸序列与两个拟南芥、水稻、甜樱桃、人类、线虫、老鼠等物种的真核翻译起始因子eIF3c相比较同源性分别为69、61%、85%、72%、38%、36%和38%.     

A nodule endophytic plant growth-promoting <Emphasis Type="Italic">Pseudomonas</Emphasis> and its effects on growth,nodulation and metal uptake in <Emphasis Type="Italic">Medicago lupulina</Emphasis> under copper stress

The aim of this study was to determine the plant growth-promoting potential of the nodule endophytic Pseudomonas brassicacearum strain Zy-2-1 when used as a co-inoculant of Medicago lupulina with Sinorhizobium meliloti under copper (Cu) stress conditions. Strain Zy-2-1 was capable of producing ACC deaminase activity, IAA and siderophores, and was able to grow in the presence of Cu²⁺ up to 2.0 mmol/L. Co-inoculation of S. meliloti with Zy-2-1 enhanced M. lupulina root fresh weight, total plant dry weight, number of nodules, nodule fresh weight and nitrogen content in the presence of 100 or 300 mg/kg Cu²⁺. In the presence of 500 mg/kg Cu²⁺, co-inoculation with S. meliloti and strain Zy-2-1 increased plant height, number of nodules, nodule fresh weight and nitrogen content in comparison to S. meliloti inoculation alone. Furthermore, a higher amount of Cu accumulation in both shoots and roots and a higher level of Cu translocation to shoots were observed in co-inoculated plants. These results demonstrate that co-inoculation of M. lupulina with S. meliloti and P. brassicacearum Zy-2-1 improves plant growth, nitrogen nutrition and metal extraction potential. This can be of practical importance in the remediation of heavy metal-contaminated soils.     

亚高寒草甸不同坡向植物光合生理和叶片形态差异

绿色植物叶片的功能性状能用来解释不同层次复杂的生态学过程,被认为对植物的生存、生长和繁殖具有重要的影响。该研究对甘南亚高寒草甸坡向梯度代表物种的叶片形态和光合特性进行测定,分析了各坡向的土壤因子,比较不同物种(矮嵩草、米口袋、蒲公英和金露梅)之间的性状差异,研究叶片光合及形态特征与土壤因子之间的相关性。结果表明:1)不同坡向的土壤因子有着显著差异,土壤含水量、土壤全磷、土壤全氮及有机碳含量总体表现为北坡南坡,而土壤温度及光照度则是南坡北坡。2)坡向上不同物种在比叶面积、净光合速率和叶δ~(13)C值等方面有着显著的差异,比如物种在北坡具有较高的比叶面积和叶片含水量,而物种在南坡具有较高的净光合速率、相对叶绿素、叶干物质量及δ~(13)C值。3)冗余分析结果显示,物种的叶片形态及光合特性与土壤因子之间都具有显著的相关关系,其中土壤含水量变化的响应最为敏感。该研究揭示了亚高寒草甸坡向梯度上植物物种在叶片功能性状上的显著分化,使得这些物种能在同一个草地群落中共存。