Current state and perspectives on erythropoietin production

Erythropoietin is a major regulator of erythropoiesis which maintains the body's red blood cell mass and tissue oxygenation at an optimum level. Recombinant human erythropoietin (rhEPO), which is a widely used therapeutic agent for the treatment of anemia and which represents one of the largest biopharmaceuticals markets, is produced from recombinant Chinese hamster ovary cells. rhEPO is a glycoprotein with complex glycan structure, which is responsible for its therapeutic efficacy, including the in vivo activity and half-life. In order to obtain an optimal and consistent glycoform profile of rhEPO and concurrently maintain a high production yield, various approaches in drug development and cell culture technology have been attempted. Recent advances in rhEPO production are classified into three types: the development of improved rhEPO molecules by protein engineering; improvement of production host cells by genetic engineering; and culture condition optimization by fine control of the production mode/system, process parameters, and culture media. In this review, we focus on rhEPO production strategies as they have progressed thus far. Furthermore, the current status of the market and outlook on rhEPO and its derivatives are discussed.     

A preliminary X-ray study of a refolded PTS EIIBfruc protein from Escherichia coli

The phosphoenolpyruvate-carbohydrate phosphotransferase system (PTS) catalyzes the phosphorylation and transportation of its sugar substrates. A sugar-specific enzyme II complex involved in the PTS finally functions to translocate substrates across the membrane. A PTS EIIB(fruc) protein, a fructose specific EIIB subunit, from Escherichia coli has been cloned, expressed, refolded, purified, and crystallized. The synchrotron data were collected to 2.6 A from the crystal of a selenomethionine substitute PTS EIIB(fruc) protein. The crystal belongs to the primitive trigonal space group P3(1)21, with unit-cell parameters of a = 33.4 A, b = 33.4 A, c = 154.0 A, and beta = 120.0 degrees . A full structure determination is under way to provide insights into the structure-function relationships of this protein.     

磺酰脲类除草剂残留的微生物降解研究进展

磺酰脲类除草剂是一类高效、低毒和高选择性的除草剂, 此类除草剂能有效地防除阔叶杂草, 其中有些品种对禾本科杂草也有抑制作用。由于该类除草剂易残留药害及容易对地表水造成污染, 因而其在环境中的持久性和环境安全性备受人们关注。本文综述了磺酰脲类除草剂的应用概况及其作用机理、降解磺酰脲类除草剂的常见微生物种类及影响微生物降解效率的因素, 最后展望了微生物修复技术与抗除草剂的转基因作物是解决除草剂残留药害的最佳途径。     

副溶血性弧菌免疫逃逸及其可能机制的研究进展

副溶血性弧菌是全球范围内威胁人体健康和食品安全的食源性致病菌。在感染人体的过程中,副溶血性弧菌通过将其效应蛋白直接注射至宿主细胞中操纵宿主,介导毒力的发挥,并进化出了一套完美的免疫逃逸策略,成功躲避免疫系统的攻击,引起急性肠胃炎、败血症和坏死性筋膜炎等疾病。副溶血性弧菌入侵上皮细胞,使胞内囊泡酸化,在与溶酶体融合之前逃逸到细胞质中,并且限制活性氧的产生,促进其在胞内生存。副溶血性弧菌可以诱导自噬,抑制NLRC4炎症小体介导的caspase-1的激活,还可以通过抑制TAK1激酶,阻止MAPK和NF-κB信号通路的激活,干扰免疫系统激活,借助多种手段共同协作从而达到免疫逃逸。本文系统总结了副溶血性弧菌现已研究的免疫逃逸机制,并对其可能存在的免疫逃逸机制提供了新的见解和方向,对深入了解副溶血性弧菌的致病机理和防控药物靶向位点的选择及研发具有重要意义。     

FoxO转录因子

FoxO家族是转录调节因子 ,也是INS IGF 1信号通路中的关键分子。FoxO基因在进化上高度保守 ,其氨基酸序列中含有 3个高度保守PKB磷酸化基序。FoxO受PI3K PKB磷酸化级联通路的调节 ,其活性与磷酸化状态直接相关。FoxO对细胞增殖、细胞凋亡等生理过程有重要调节作用 ,并可能在免疫系统发育中对免疫细胞的凋亡及亚群间的平衡起一定调节作用。     

Root-tip diameters of woody species in subalpine Abies forest

We clarified the differences in root-tip diameter (RTD) among tree and shrub species in an Abies forest. To evaluate the effects of sampling month and tree size on RTD, we measured the root-tip diameters of mature individuals of nine woody species and sapling individuals of two Abies species in a subalpine Abies forest on Mount Shimagare in central Japan. Species, sampling month, and their interaction affected RTD; however, the differences in RTD between some pairs of species were consistent across sampling months. The woody species fell into two groups, based on RTD size: tree species with larger RTDs (group 1) and shrub species with smaller RTDs (group 2). Seasonal changes in RTD were observed in three species and showed different patterns among species. Tree size did not affect RTD for either Abies species; however, there was an interaction between tree size and sampling month for Abies veitchii. The woody species category had the greatest effect on RTD, followed by sampling month and then tree size.     

Thermal response in murine L929 cells lacking αB-crystallin expression and αB-crystallin expressing L929 transfectants

We investigated the role of B-crystallin expression in the development of thermotolerance in murine L929 cells. An initial heat-shock of 10 min at 45°C induced thermotolerance in these cells to a heat challenge at 45°C administered 24 h later. The thermotolerance ratio at 10^–1 isosurvival was 1.7. Expression of B-crystallin gene was not detected during the 24 h incubation at 37°C following heat shock by either northern or western blots. In contrast, inducible HSP70 synthesis was observed during this time period. Thus, this cell line provided an unique system in which to examine the effects of transfected B-crystallin on thermoresistance and thermotolerance. Cells stably transfected with B-crystallin under the control of an inducible promoter did not show a significant increase in the ability to develop thermotolerance. However, a stably transfected L929 clone expressing high levels of constitutive B-crystallin exhibited an approximately 50% increase in thermal resistance over parental and control cells. Though expression of B-crystallin is not requisite for the development of thermotolerance in L929 cells, overexpression of transfected B-crystallin can contribute to increased thermoresistance.     

ESI-Q-TOF-MS直接进样法比较陕西五个不同地区丹参的化学成分差异（英文）

该研究采用ESI-Q-TOF-MS直接进样分析法对陕西商州、洛南、大荔、丹凤和铜川等五个地区丹参的化学成分进行了比较分析,通过丹参水溶性和脂溶性成分的质谱丰度差异评价了不同地区丹参化学成分含量的变化,对不同产地丹参的化学成分进行了鉴定,综合分析选出了最优的丹参种植产地。结果表明:五地丹参均含有丹参酮ⅡA、隐丹参酮、丹参酮Ⅰ、二氢丹参酮、丹参酚酮、次丹参醌、丹参醌Ⅱ等9种脂溶性化学成分和丹参素、咖啡酸、阿魏酸、迷迭香酸、原紫草酸、紫草酸、原儿茶醛、丹酚酸A、丹酚酸B等9种水溶性化学成分,其中丹参素钠、紫草酸、丹酚酸B和隐丹参酮的含量普遍较高,质谱丰度均大于30%。但是,随着种植环境不同,不同地区丹参的化学成分含量差异很大,如商州产丹参中含有较多具有生物活性的丹参酮类物质,其中丹参酮Ⅰ含量远远高于其他四个产地,质谱丰度达到72.6%,而其他地区丹参酮Ⅰ的质谱丰度为1.8%～11.3%。这表明丹参质量按照地区排序为商州>铜川>大荔>洛南>丹凤。该方法为中药药材质量评价提供了科学、可靠、便捷的途径,为药材规格等级的制定提供了新途径,为陕西丹参种植区域的选择提供了重要信息。     

果蝇求偶行为分子调控机制的研究进展

果蝇(Drosophila)的求偶行为受多个基因调控,例如fruitless(fru)、dissatisfaction(dsf)和retained(retn)等。它们通过不同的剪切方式产生特异性产物,利用这些产物来控制雌雄果蝇的求偶行为,它们的剪切方式是雌雄果蝇求偶行为和性别决定所必需的。主要阐述了这些基因在果蝇求偶行为方面的分子调控机制,为进一步研究果蝇的求偶行为和性别决定提供理论依据。