Scorpion Venom Heat-Resistant Peptide (SVHRP) Enhances Neurogenesis and Neurite Outgrowth of Immature Neurons in Adult Mice by Up-Regulating Brain-Derived Neurotrophic Factor (BDNF)

Scorpion venom heat-resistant peptide (SVHRP) is a component purified from Buthus martensii Karsch scorpion venom. Although scorpions and their venom have been used in Traditional Chinese Medicine (TCM) to treat chronic neurological disorders, the underlying mechanisms of these treatments remain unknown. We applied SVHRP in vitro and in vivo to understand its effects on the neurogenesis and maturation of adult immature neurons and explore associated molecular mechanisms. SVHRP administration increased the number of 5-bromo-2’-dexoxyuridine (BrdU)-positive cells, BrdU- positive/neuron-specific nuclear protein (NeuN)-positive neurons, and polysialylated-neural cell adhesion molecule (PSA-NCAM)-positive immature neurons in the subventricular zone (SVZ) and subgranular zone (SGZ) of hippocampus. Furthermore immature neurons incubated with SVHRP-pretreated astrocyte-conditioned medium exhibited significantly increased neurite length compared with those incubated with normal astrocyte-conditioned medium. This neurotrophic effect was further confirmed in vivo by detecting an increased average single area and whole area of immature neurons in the SGZ, SVZ and olfactory bulb (OB) in the adult mouse brain. In contrast to normal astrocyte-conditioned medium, higher concentrations of brain-derived neurotrophic factor (BDNF) but not nerve growth factor (NGF) or glial cell line-derived neurotrophic factor (GDNF) was detected in the conditioned medium of SVHRP-pretreated astrocytes, and blocking BDNF using anti-BDNF antibodies eliminated these SVHRP-dependent neurotrophic effects. In SVHRP treated mouse brain, more glial fibrillary acidic protein (GFAP)-positive cells were detected. Furthermore, immunohistochemistry revealed increased numbers of GFAP/BDNF double-positive cells, which agrees with the observed changes in the culture system. This paper describes novel effects of scorpion venom-originated peptide on the stem cells and suggests the potential therapeutic values of SVHRP.     

Numerical simulation of pulsatile flow in a compliant curved tube model of a coronary artery

The endothelial cells (ECs) lining a blood vessel wall are exposed to both the wall shear stress (WSS) of blood flow and the circumferential strain (CS) of pulsing artery wall motion. These two forces and their interaction are believed to play a role in determining remodeling of the vessel wall and development of arterial disease (atherosclerosis). This study focused on the WSS and CS dynamic behavior in a compliant model of a coronary artery taking into account the curvature of the bending artery and physiological radial wall motion. A three-dimensional finite element model with transient flow and moving boundaries was set up to simulate pulsatile flow with physiological pressure and flow wave forms characteristic of the coronary arteries. The characteristic coronary artery curvature and flow conditions applied to the simulation were: aspect ratio (lambda) = 10, diameter variation (DV) = 6 percent, mean Reynolds number (Re) = 150, and unsteadiness parameter (alpha) = 3. The results show that mean WSS is about 50 percent lower on the inside wall than the outside wall while WSS oscillation is stronger on the inside wall. The stress phase angle (SPA) between CS and WSS, which characterizes the dynamics of the mechanical force pattern applied to the endothelial cell layer, shows that CS and WSS are more out of phase in the coronaries than in any other region of the circulation (-220 deg on the outside wall, -250 deg on the inside wall). This suggests that in addition to WSS, SPA may play a role in localization of coronary atherosclerosis.     

Genetic animal models for evaluating the role of autophagy in etiopathogenesis of Parkinson disease

Parkinson disease (PD) is the most common neurodegenerative movement disorder and is characterized pathologically by the formation of ubiquitin and SNCA/α-synuclein-containing inclusions (Lewy bodies), dystrophic midbrain dopaminergic (DAergic) terminals, and degeneration of midbrain DAergic neurons. The vast majority of PD occurs sporadically, while approximately 5% of all PD cases are inherited. Genetic mutations of a few genes have been identified as causes of familiar PD, i.e., mutations in SNCA, PARK2/parkin, UCHL1, PARK7/DJ1, PINK1 and LRRK2, leading to DAergic cell death, but variable pathological changes. The evidence supports the hypothesis that several pathogenic mechanisms are likely involved at initial stages of the disease, and eventually they merge to cause parkinsonism. The current challenge facing PD research is to unravel the components in these pathways that contribute to the pathogenesis of PD. Accumulating evidence has implicated dysfunctional autophagy, a regulated lysosomal pathway with a capacity for clearing protein aggregates and cellular organelles, as one of the pathogenic systems contributing to the development of idiopathic PD.     

Magnesium Deficiency Enhances Hydrogen Peroxide Production and Oxidative Damage in Chick Embryo Hepatocyte In Vitro

Magnesium deficiency and oxidative stress have been identified as correlative factors in many diseases. The origin of free radicals correlated with oxidative damage resulting from Mg-deficiency is unclear at the cellular level. To investigate whether hydrogen peroxide (H₂O₂) is associated in the oxidative stress induced by Mg-deficiency, the effect of Mg²⁺ deficiency (0, 0.4, 0.7 mM) on the metabolism of H₂O₂ was investigated in cultured chick embryo hepatocytes. After being cultured in the media with various concentrations of Mg²⁺ for 1, 2, 4, 6 and 10 days, parameters of H₂O₂ production, catalase activity, lipid peroxidation, intracellular total Mg and cell viability were analyzed. Results demonstrated that long-term incubation of chick embryo hepatocyte in extracellular Mg²⁺-deprivative and Mg²⁺-deficient (0.4 mM) states significantly enhanced the production of H₂O₂ (approximately twofold, respectively) and lipid peroxidation in the cell cultures, while decreasing the cell viability. Additionally, the reversing action of Mg²⁺ re-added to 1.0 mM and the partial reversing action of dimethylthiourea suggested that (i) [Mg²⁺]_e deficiency induced the increase of H₂O₂ production, (ii) [Mg²⁺]_e deficiency decreased catalase activity in chick embryo hepatocyte in vitro, subsequently causing oxidative stress and cell peroxidative damage.     

不同转移潜能肿瘤细胞肝素酶的表达

目的研究肝素酶(Heparanase,Hpa)表达水平与人类肿瘤转移的相关性。方法利用半定量RT-PCR、免疫组织化学(S-P法)和Westernblot检测2组4种不同转移潜能的人类肿瘤细胞系中HpamRNA和蛋白的表达水平。结果HpamRNA和蛋白相对表达量在高转移潜能人类肺癌细胞(0·757±0·033,0·670±0·020)、乳腺癌细胞(0·617±0·024,0·661±0·013)中明显高于相应的低转移潜能肺癌细胞(0·518±0·012,0·406±0·012)、乳腺癌细胞(0·170±0·016,0·227±0·011)。结论在所研究的人类肿瘤中,HpamRNA和蛋白的表达水平与肿瘤的转移能力呈正相关。     

中国三江平原产新鞭毛藻

本文论述了采自中国三江平原(黑龙江省宝清县)的新鞭毛藻,共1新属6新种1新变种.新属为Cercobodoides gen. nov.; 6新种为Tranguillus pyriformis sp. nov., Cercobodo obliqua. sp. nov., Cercobodoides heilongjianica sp. nov.; Oicomonas ovata Sp. nov., Rhizomastix borealis sp. nov., Trigonomonas papillata sp. nov.; 1新变种为Tranguillus pyriformis var, obovata var. nov.     

Comparative Transcriptome Analyses Reveal Genes Related to Spine Development in Cucumber (<i>Cucumis sativus</i>)

Fruit spine is an important quality trait of cucumber. To better understand the molecular basis of cucumber spine development and function, RNA-Seq was performed to identify differentially expressed genes (DEGs) in fruit spines of different development stages, namely, 8 days before anthesis (SpBA8), anthesis (SpA) and 8 days after anthesis (SpAA8). Stage-wise comparisons obtained 2,259 (SpBA8 vs. SpA), 4,551 (SpA vs. SpAA8), and 5,290 (SpBA8 vs. SpAA8) DEGs. All the DEGs were classified into eight expression clusters by trend analysis. Among these DEGs, in addition to the Mict, Tril, CsTTG1, CsMYB6, NS, and Tu genes that have been reported to regulate fruit spine formation, we found that the CsHDG11, CsSCL8, CsSPL8, CsZFP6 and CsZFP8 may also be involved in spine development in cucumber. Our study provides a theoretical basis for further research on molecular mechanisms of spine development in cucumber.     

中国生物多样性在线数据处理平台的构建

高质量的生物多样性数据能够为生物多样性的研究与保护提供数据支撑。目前研究人员开发了大量的生物多样性数据处理软件或工具, 包括工作流系统、R语言包、Python语言包和Excel工具等, 但是使用这些软件或工具需要用户安装相应的软件客户端, 并掌握一定的编程语言、软件开发和复杂的Excel公式等知识和技能。为降低用户的学习成本和使用门槛, 本文采用了Browser/Server模式设计技术、Web技术、可视化技术、响应式开发技术、网络爬虫技术、数据处理技术和Solr智能检索技术等, 针对不同维度的生物多样性数据设计和开发了相应的数据处理模块, 构建了中国生物多样性在线数据处理平台(http://dp.iflora.cn/)。该平台能够有效地帮助科研人员对物种名称、地理位置、时间日期和经纬度等数据进行处理, 并提供数据格式转换、数据质量评测和资源统计分析等辅助功能, 帮助科研人员实现零代码和低门槛地处理生物多样性数据, 提供便捷、高效和简单的数据清洗、校正、转换和整合等数据处理渠道, 为生物多样性研究和保护提供信息化技术支持与服务。     

基因重组与外源铁离子对大肠杆菌合成血红素的影响

【背景】大肠杆菌通过C5途径合成卟啉及血红素,5-氨基乙酰丙酸(5-aminolevulinic acid,5-ALA)是C5途径中关键的前体物质,血红素由原卟啉IX (protoporphyrin IX, PPIX)螯合一个铁离子所形成,目前5-ALA与PPIX的外泌对卟啉的积累和血红素合成的影响尚不清楚。【目的】构建5-ALA外泌蛋白基因rhtA和卟啉外泌蛋白基因tolC双缺失的大肠杆菌以积累卟啉,同时外源添加铁离子,并过表达亚铁螯合酶基因hemH及参与铁摄取的基因efeB,促进卟啉向血红素的转化。【方法】通过Red同源重组敲除大肠杆菌BL21(DE3)的rhtA和tolC,并外源添加不同浓度的FeSO₄及Fe₂(SO₄)₃,同时构建重组质粒pEHE过表达hemH和efeB,检测卟啉和血红素含量,分析卟啉向血红素的转化。【结果】敲除rhtA和tolC对菌体生长无显著影响,与野生菌WT相比,敲除菌株WT-RT的卟啉含量增加,血红素合成略有提升。外源添加100μmol/L Fe²⁺     

土壤酶计量揭示了武夷山黄山松林土壤微生物沿海拔梯度的碳磷限制变化

了解土壤胞外酶活性和酶计量的变化对评估山地生态系统土壤养分有效性和微生物的营养限制状况具有重要意义.然而,亚热带山地森林土壤微生物的营养限制状况对海拔梯度变化的响应及其驱动因素尚不清楚.本研究以武夷山不同海拔(1200～2000 m)黄山松林为对象,测定了土壤基本性质、微生物生物量以及与碳(C)、氮(N)、磷(P)循环...