汉滩病毒膜蛋白重组腺病毒的构建表达及免疫效果研究

探讨利用腺病毒载体作为汉滩病毒基因工程疫苗载体的可行性。通过PCR扩增,得到完整的汉滩病毒76-118株M片段编码区,将该片段克隆入质粒pAdTrackCMV的CMV启动子下游,得到阳性克隆pAdTrackCMV—M。Pmel线性化的阳性克隆与腺病毒骨架载体pAdEasy—1共转化大肠杆菌BJ5183,经同源重组后得到重组病毒pAdEasy—M。pAdEasy—M经PacI线性化后,脂质体介导转染293细胞,经Western—blot检测表明,G1、G2基因在293细胞中得到表达。重组病毒免疫BALB／c小鼠,产生了具有一定中和活性的抗体。该研究为进一步研制以腺病毒为活载体的工程疫苗奠定了基础。     

不同生境条件下黄芩光合日变化与环境因子的关系

在黄芩盛花期,测临江、长春、洮南3个不同生境条件下黄芩Pn及环境因子的日变化,对测得数据进行统计分析,探讨黄芩Pn与环境因子的关系,为吉林省黄芩规范化种植提供理论依据.结果表明,3个不同生境黄芩Pn日变化均呈不明显双峰曲线,有轻微光合"午休"现象,黄芩Pn中午降低均为气孔限制;三地黄芩Pn与PAR均呈极显著正相关(p<0.01),长春黄芩Pn与Ca呈极显著正相关(p<0.01),洮南黄芩Pn与RH呈显著正相关(p<0.05);3个不同生境环境因子对Pn的直接作用由大到小分别为临江PAR＞Ca＞Ta＞RH＞TL,长春Ta＞RH＞PAR＞Ca＞TL,洮南PAR＞RH＞TL＞Ca＞Ta;低的空气湿度是产生光合"午休"现象的重要生态因子;临江高温高湿、长春大气CO2浓度低、洮南相对湿度低是影响各生境黄芩Pn的主要环境因子;对黄芩Pn影响是PAR、Ta、RH、Ca相互影响综合作用的结果,在不同生境下,发挥主导作用的环境因子不同.     

Clinical analysis of the treatment of spinocerebellar ataxia and multiple system atrophy-cerebellar type with umbilical cord mesenchymal stromal cells

Background aimsThe aims of this study were to observe the safety and effectiveness of umbilical cord mesenchymal stromal cells (UC-MSC) in the treatment of spinocerebellar ataxia (SCA) and multiple system atrophy-cerebellar type (MSA-C).MethodsFrom October 2009 to September 2010, 14 cases of SCA and 10 cases of MSA-C were given UC-MSC by weekly intrathecal injection, at a dose of 1 × 10⁶/kg four times as one course. All the patients received one course of treatment, except three patients who received two courses. The movement ability and quality of daily life were evaluated with the International Cooperative Ataxia Rating Scale (ICARS) and Activity of Daily Living Scale (ADL) and the scores compared with those before cell therapy. A follow-up of 6–15 months was carried out for all of the patients.ResultsThe results showed that the ICARS and ADL scores were significantly decreased 1 month after treatment (P < 0.01). The symptoms, including unstable walking and standing, slow movement, fine motor disorders of the upper limbs, writing difficulties and dysarthria, were greatly improved except for one patient, who had no response. The observed side-effects included dizziness (four patients), back pain (two cases) and headache (one case), which disappeared within 1–3 days. During the follow-up, 10 cases remained stable for half a year or longer, while 14 cases had regressed to the status prior to the treatment within 1–14 months (an average of 3 months).ConclusionsIntrathecal injection of UC-MSC is safe and can delay the progression of neurologic deficits for SCA and MSA-C patients.     

Vimentin is important in the neural differentiation of PC12 cells promoted by sialylation

Sialic acid modification is a kind of post-translational modification. To investigate the regulation effect of sialic acid on neural differentiation, we used CycloManN propanyl perac (CycloManN pro), a metabolic precursor of sialic acid, to treat PC12 cells. We noted that CycloManN pro indeed robustly promoted global sialylation detected by MAL II lectin blot in PC12 cells. Simultaneously, we interestingly found that the neurite outgrowth of PC12 cells was significantly promoted by the CycloManN pro treatment. The profile analysis of sialylated proteins showed that a protein band at 55KD was greatly enhanced especially in PC12L cells after CycloManN pro treatment. After enrichment with lectin MAL II, the proteins in this band were analyzed by mass spectrometry. The results showed that 23 proteins were in the band, but the score of vimentin was the highest among them. To investigate further the role of vimentin in the process of neurite differentiation, vimentin construct was transfected into PC12 cells. We interestingly observed that ectopic expression of vimentin significantly enhanced the neurite outgrowth induced by CycloManN pro. However, after three potential glycosylation sites (Ser-7, Thr-33, Ser-34:) of vimentin were mutated to alanine, overexpression of the mutated vimentin completely lost the enhancement activity for the neural differentiation even in the presence of CycloManN pro. Taken together, our study demonstrated that vimentin was important in the induction of neural differentiation by CycloManN pro.     

Enzymatic activity and substrate specificity of mitogen-activated protein kinase p38alpha in different phosphorylation states

The mitogen-activated protein (MAP) kinases are essential signaling molecules that mediate many cellular effects of growth factors, cytokines, and stress stimuli. Full activation of the MAP kinases requires dual phosphorylation of the Thr and Tyr residues in the TXY motif of the activation loop by MAP kinase kinases. Down-regulation of MAP kinase activity can be initiated by multiple serine/threonine phosphatases, tyrosine-specific phosphatases, and dual specificity phosphatases (MAP kinase phosphatases). This would inevitably lead to the formation of monophosphorylated MAP kinases. However, the biological functions of these monophosphorylated MAP kinases are currently not clear. In this study, we have prepared MAP kinase p38alpha, a member of the MAP kinase family, in all phosphorylated forms and characterized their biochemical properties. Our results indicated the following: (i) p38alpha phosphorylated at both Thr-180 and Tyr-182 was 10-20-fold more active than p38alpha phosphorylated at Thr-180 only, whereas p38alpha phosphorylated at Tyr-182 alone was inactive; (ii) the dual-specific MKP5, the tyrosine-specific hematopoietic protein-tyrosine phosphatase, and the serine/threonine-specific PP2Calpha are all highly specific for the dephosphorylation of p38alpha, and the dephosphorylation rates were significantly affected by different phosphorylated states of p38alpha; (iii) the N-terminal domain of MPK5 has no effect on enzyme catalysis, whereas deletion of the MAP kinase-binding domain in MKP5 leads to a 370-fold decrease in k(cat)/K(m) for the dephosphorylation of p38alpha. This study has thus revealed the quantitative contributions of phosphorylation of Thr, Tyr, or both to the activation of p38alpha and to the substrate specificity for various phosphatases.     

分子标记在油菜杂种优势利用中的研究进展

杂种优势是一种普遍存在的生物学现象, 是提高作物产量的重要途径, 因而受到越来越广泛的重视。分子标记是近年兴起的一种新型的生物技术, 国内外已利用RFLP、RAPD、AFLP、SSR、ISSR和SRAP等多种分子标记技术对油菜的杂种 优势进行了广泛的研究, 取得了很多有价值的研究成果。本文综述了分子标记在油菜授粉控制系统中关键基因标记、亲本遗传多样性分析、杂种优势群划分、杂种纯度鉴定和杂种优势预测中的研究进展。通过对不同作物间的比较, 探讨了分子标记在油菜杂种优势利用中的研究深度, 并对分子标记在油菜杂种优势预测中应注意的问题进行了讨论。     

Ribosomal proteins S13 and L23 promote multidrug resistance in gastric cancer cells by suppressing drug-induced apoptosis

Ribosomal proteins (RP) S13 and RPL23 were previously identified as two upregulated genes in a multidrug-resistant gastric cancer cell line SGC7901/VCR compared to its parental cell SGC7901 by differential display PCR. The aim of this study was to explore the roles of RPS13 and RPL23 in multidrug resistance (MDR) in gastric cancer cells. RPS13 and RPL23 were genetically overexpressed in SGC7901 cells, respectively. Either RPS13 or RPL23 enhanced resistance of SGC7901 cells to vincristine, adriamycin, and 5-fludrouracil. RPL23 also enhanced resistance of SGC7901 cells to cisplatin. Overexpression of either RPS13 or RPL23 did not alter the population doubling time, [³H]leucine incorporation, and intracellular adriamycin accumulation of SGC7901 cells. However, either RPS13 or RPL23 could protect SGC7901 cells from undergoing vincristine-induced apoptosis. Western blot analysis revealed that both RPS13 and RPL23 significantly increased the expression level of Bcl-2 and Bcl-2/Bax ratio in SGC7901 cells. In addition, overexpression of RPL23 enhanced glutathione S-transferase (GST) activity and intracellular glutathione content in SGC7901 cells. Together, this work demonstrates that either RPS13 or RPL23 can promote MDR in gastric cancer cells by suppressing drug-induced apoptosis, and that RPL23 may also promote MDR in gastric cancer cells through regulation of glutathione S-transferase-mediated drug-detoxifying system.     

无瓣海桑模拟湿地系统对污水的争化效应

在温室中建立红树林植物无瓣海桑(Sonneratia apetala Buch-Ham)模拟湿地系统,分别用正常浓度(SW)、5倍浓度(FW)和10倍浓度(TW)3种人工配制的生活污水定时定量对模拟系统污灌4个月,无瓣海桑模拟湿地系统对人工合成污水中污染物总净化率平均为N 84.6%,P 91.2%,Cd 91.2%,Pb 94.8%,Zn 84.9%,Cu 87.1%,其中土壤子系统在总净化率中所占比例平均为N 54.5%,P 76.5%,Cd 99.1%,Pb 99.6%,Zn 99.3%,Cu 99.2%.重金属有99%以上是积累在土壤中,表明土壤子系统是本模拟湿地系统净化的主体,这也是植物借以避免污染物伤害的原因之一.与不栽种植物的比较,栽种无瓣海桑的系统中土壤子系统的重金属净化率高,说明红树植物在模拟湿地净化系统中起了重要作用.由于土壤中N、P被无瓣海桑吸收用于生长,栽种了无瓣海桑的土壤子系统的积累量比不栽种的子系统少.     

细胞色素P450介导抗性的进化可塑性

细胞色素P450是超基因家族,由其介导的杀虫剂代谢解毒的增强是昆虫产生抗药性的普遍而主要的机制。近年的研究表明,细胞色素P450介导的代谢抗性表现出一定程度的进化可塑性:即使是同种昆虫的不同种群在相同种类杀虫剂的胁迫下,进化选择出的抗性相关的细胞色素P450也有所不同,抗性的产生也可以是几种不同细胞色素P450协同作用或控制P450表达的调控因子的不同。