Different leaf carbon,nitrogen, and phosphorus stoichiometry and carbon and nitrogen isotopes among peatland plants in northeastern China

Plant and Soil - Plant carbon (C), nitrogen (N), phosphorus (P) levels and their stoichiometry and N uptake strategies are important aspects influencing vegetation composition and C dynamics in...     

线粒体移植增强人神经胶质瘤U87细胞的辐射敏感性

线粒体移植( mitochondrial transplantation)是从患者正常组织分离线粒体然后注入线粒体损伤或缺失的部位,使损伤细胞获得救治、器官功能得以恢复的全新干预技术。本研究重点探讨线粒体移植对人神经胶质瘤细胞(U87)辐射敏感性的影响。提取人星形胶质细胞(human astrocytes, HA)的线粒体,用荧光探针Mito-Tracker Red进行标记后再与U87细胞共培养,激光共聚焦显微镜观察发现,Mito-Tracker Red的红色荧光大量出现在U87细胞内;随后对进入细胞内的游离线粒体荧光强度进行定量分析,游离线粒体和U87细胞共培养12 h时,单细胞内荧光强度由本底值0.08上升至1.83,表明游离线粒体可以通过共培养方式进入U87细胞内。随后给予U87细胞X射线辐照,Western印迹结果显示,联合组与单独辐照组相比,Cyto-C和Bax的表达量分别由179.5%和198.5%升高至251.72%和256.10%,Bcl-2的表达量由57.17%降低至22.23%;使用Annexin V/PI双染法检测到联合组U87细胞凋亡量相比单独辐照组的3.1%和23.5%上升至19.2%和43.8%;RT-CES检测结果表明,96 h内联合组U87细胞生长曲线被抑制;联合组克隆形成率相对单独辐照组的53%下降至29.3%。鬼笔环肽染色发现,线粒体移植组细胞表面丝状伪足相比对照组明显减少。本研究提示,线粒体移植能够促进辐射诱导的肿瘤细胞凋亡,对U87细胞具有辐射增敏作用,其作用机制与重新激活线粒体凋亡通路、降低肿瘤恶性程度有关。     

Directing and Potentiating Stem Cell-Mediated Angiogenesis and Tissue Repair by Cell Surface E-Selectin Coating

Stem cell therapy has emerged as a promising approach for treatment of a number of diseases, including delayed and non-healing wounds. However, targeted systemic delivery of therapeutic cells to the dysfunctional tissues remains one formidable challenge. Herein, we present a targeted nanocarrier-mediated cell delivery method by coating the surface of the cell to be delivered with dendrimer nanocarriers modified with adhesion molecules. Infused nanocarrier-coated cells reach to destination via recognition and association with the counterpart adhesion molecules highly or selectively expressed on the activated endothelium in diseased tissues. Once anchored on the activated endothelium, nanocarriers-coated transporting cells undergo transendothelial migration, extravasation and homing to the targeted tissues to execute their therapeutic role. We now demonstrate feasibility, efficacy and safety of our targeted nanocarrier for delivery of bone marrow cells (BMC) to cutaneous wound tissues and grafted corneas and its advantages over conventional BMC transplantation in mouse models for wound healing and neovascularization. This versatile platform is suited for targeted systemic delivery of virtually any type of therapeutic cell.     

Effects of Electro-Acupuncture on IGF-I Expression in Spared Dorsal Root Ganglia and Associated Spinal Dorsal Horn in Cats Subjected to Adjacent Dorsal Root Ganglionectomies

The effects of electro-acupuncture (EA) on insulin-like growth factor-I (IGF-I) expression in the spared dorsal root ganglia (DRG) and associated spinal dorsal horns were explored in cats subjected to unilateral removal of L₁–L₅ and L₇–S₂ DRG, sparing the L₆ DRG. Immunohistochemistry revealed the presence of IGF-I immunoreactive products in the L₆ DRG neurons and some neurons and glial cells in the spinal cord. Western blot demonstrated that the level of IGF-I was significantly up-regulated both in the spared DRG and the dorsal horns of L₃ and L₆ cord segments at both 7 and 14 days post operation following EA. The present findings demonstrated the association between neuroplasticity and IGF-I expression, suggesting the possible role of IGF-I in EA promoted spinal cord plasticity.     

亚洲玉米螟神经肽羽化激素基因cDNA的克隆及组织表达

羽化激素对调节昆虫的蜕皮和发育起关键作用。亚洲玉米螟Ostrinia furnacalis是亚洲农业重要害虫之一,本实验研究了亚洲玉米螟羽化激素基因cDNA的分子结构和表达模式。利用兼并性引物RT-PCR技术,克隆了亚洲玉米螟羽化激素基因cDNA的中间片段,然后再用RACE方法,获得羽化激素基因的 cDNA全长序列。结果表明： 亚洲玉米螟羽化激素基因cDNA全长986 bp（GenBank登录号： DQ668369）,开放阅读框为267 bp,编码88个氨基酸的前体蛋白,其中包括前26个氨基酸组成的信号肽和62个氨基酸的成熟肽。亚洲玉米螟羽化激素基因与烟草天蛾、棉铃虫和家蚕已报道同源基因的同源性较高,分别为79.5%、77.3%和67.0%,与黑腹果蝇同源基因的同源性最低,仅45.5%。亚洲玉米螟羽化激素基因mRNA只在脑中表达,在咽下神经节、胸神经节、腹神经节等神经组织中检测不到,在非神经组织如中肠、脂肪体和表皮中也不表达。     

Characterization of the complete mitochondrial genome of the giant silkworm moth, Eriogyna pyretorum (Lepidoptera: Saturniidae)

The complete mitochondrial genome (mitogenome) of Eriogyna pyretorum (Lepidoptera: Saturniidae) was determined as being composed of 15,327 base pairs (bp), including 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and a control region. The arrangement of the PCGs is the same as that found in the other sequenced lepidopteran. The AT skewness for the E. pyretorum mitogenome is slightly negative (-0.031), indicating the occurrence of more Ts than As. The nucleotide composition of the E. pyretorum mitogenome is also biased toward A + T nucleotides (80.82%). All PCGs are initiated by ATN codons, except for cytochrome c oxidase subunit 1 and 2 (cox1 and cox2). Two of the 13 PCGs harbor the incomplete termination codon by T. All tRNA genes have a typical clover-leaf structure of mitochondrial tRNA, with the exception of trnS1(AGN) and trnS2(UCN). Phylogenetic analysis among the available lepidopteran species supports the current morphology-based hypothesis that Bombycoidea, Geometroidea, Notodontidea, Papilionoidea and Pyraloidea are monophyletic. As has been previously suggested, Bombycidae (Bombyx mori and Bombyx mandarina), Sphingoidae (Manduca sexta) and Saturniidae (Antheraea pernyi, Antheraea yamamai, E. pyretorum and Caligula boisduvalii) formed a group.     

Effects of water level and light intensity on capsule production dynamics of Sphagnum capillifolium

 选取尖叶泥炭藓(Sphagnum capillifolium)为试验材料, 在模拟水位与光强条件下, 对人工构建的苔藓植物群落进行室内培养, 每隔1-3天观察并记录植株高度、孢蒴变化过程及变化时间, 分析了不同水位与光强条件对孢蒴生产的植物功能属性动态的影响。水位上升促进了蒴柄伸长及植株高增长, 增加了孢蒴开裂率及遮蔽率。光强增加有助于孢蒴生长, 并提高了孢蒴开裂率。在孢蒴直径以及植株高增长性状上, 水位与光强存在交互作用。水位与光强对孢蒴增长率均没有影响。此外, 水位升高与光强增加使孢蒴成熟及蒴柄伸长时间提前, 总体上使孢子释放时间分别提前了4.0 d和4.8 d, 由此可能减小了孢子体因受夏季干旱影响而败育的风险。孢子释放后, 繁殖株高增长加速, 可为未来的再次繁殖奠定基础。     

Life sciences and biotechnology in China

Life science and biotechnology have become a top priority in research and development in many countries as the world marches into the new century. China as a developing country with a 1.3 billion population and booming economy is actively meeting the challenge of a new era in this area of research. Owing to support from the government and the scientific community, and reform to improve the infrastructure, recent years have witnessed a rapid progress in some important fields of life science and biotechnology in China, such as genomics and protein sciences, neuroscience, systematics, super-hybrid rice research, stem cell and cloning technology, gene therapy and drug/vaccine development. The planned expansion and development of innovation in related sectors and the area of bioethics are described and discussed.     

Design and synthesis of novel multivalent mannosides targeting the mannose receptor

According to the characteristics of C-type lectin-like domains in the mannose receptor (MR), a novel design of multivalent mannosides targeting the MR was accomplished. Beginning with a divalent mannoside as the sugar unit, a series of multivalent mannosides with variations in both valence and space were synthesized in a convergent approach. The synthetic multivalent mannosides are to be explored to study MR-sugar binding events.