Neuritin Attenuates Neuronal Apoptosis Mediated by Endoplasmic Reticulum Stress In Vitro

Neuritin is an extracellular glycophosphatidylinositol-linked protein that promotes neuronal survival, differentiation, function, and repair, but the exact mechanism of this neuroprotective effect remains unclear. Meanwhile, endoplasmic reticulum stress (ERS) induced apoptosis is attracting increased attention. In this work, we hypothesized that neuritin inhibited ERS to protect cortical neurons. To check this hypothesis, we exposed primary cultured cortical neurons to oxygen and glucose deprivation (OGD) for 45 min followed by reperfusion (R) to activate ERS. We then performed resuscitation for 6, 12, 24, and 48 h. ERS-related factors such as glucose-regulated protein 78 (GRP78), caspase-12 and CHOP were detected by Western blotting and quantitative real-time polymerase chain reaction assay. Apoptosis was assessed by Annexin V binding and propidium iodide staining. Ultrastructural changes of endoplasmic reticulum were observed under a transmission electron microscope. Results showed that GRP78 expression significantly increased at 12, 24, and 48 h and peaked at 24 h. Caspase-12 and CHOP expression significantly increased in a time-dependent manner at 12, 24, and 48 h. GRP78, caspase-12 and CHOP expression as well as apoptosis rate of primary cultured neurons and the ultrastructural changes of endoplasmic reticulum in the OGD/R?+?neuritin group significantly improved compared with the OGD/R group. In conclusion, the neuroprotection function of neuritin may be involved in ERS pathways.     

A bifunctional cellulase–xylanase of a new Chryseobacterium strain isolated from the dung of a straw‐fed cattle

A new cellulolytic strain of Chryseobacterium genus was screened from the dung of a cattle fed with cereal straw. A putative cellulase gene (cbGH5) belonging to glycoside hydrolase family 5 subfamily 46 (GH5_46) was identified and cloned by degenerate PCR plus genome walking. The CbGH5 protein was overexpressed in Pichia pastoris, purified and characterized. It is the first bifunctional cellulase–xylanase reported in GH5_46 as well as in Chryseobacterium genus. The enzyme showed an endoglucanase activity on carboxymethylcellulose of 3237 μmol min^?1 mg^?1 at pH 9, 90 °C and a xylanase activity on birchwood xylan of 1793 μmol min^?1 mg^?1 at pH 8, 90 °C. The activity level and thermophilicity are in the front rank of all the known cellulases and xylanases. Core hydrophobicity had a positive effect on the thermophilicity of this enzyme. When similar quantity of enzymatic activity units was applied on the straws of wheat, rice, corn and oilseed rape, CbGH5 could obtain 3.5–5.0× glucose and 1.2–1.8× xylose than a mixed commercial cellulase plus xylanase of Novozymes. When applied on spent mushroom substrates made from the four straws, CbGH5 could obtain 9.2–15.7× glucose and 3.5–4.3× xylose than the mixed Novozymes cellulase+xylanase. The results suggest that CbGH5 could be a promising candidate for industrial lignocellulosic biomass conversion.     

从水稻根部悬浮培养细胞分离原生质体及植株再生

以长香稻(Oryza sativa L．)(糯稻)的幼嫩种子根为材料,在Ms和N6培养基上诱导产生结构松软而分散的愈伤组织,经过AA液体培养基振荡悬浮培养,悬浮培养细胞经酶解后得到了活性较高的原生质体,试验结果表明这是分离原生质体较理想的材料。在附加2,4-D lmg／L(以下单位同)、KT(激动素)0．2、各氨酰胺876、天门冬酰胺266的Ms琼脂糖培养基中,诱导出了大量愈伤组织,在含KT2、NAA(α-萘乙酸)0．2、zT(玉米素)0．2、cH(水解酪蛋白)1000和4％椰子汁的N6培养基中成功地诱导出了由原生质体再生的植株。当代原生质体再生植株能正常开花、结实、产生种子;染色体数均为二倍性(2n＝24),最显著的特点是结实率低,穗粒数减步、生育期延迟。     

Endurance at intermediate swimming speeds of Atlantic mackerel, Scomber scombrus L., herring, Clupea harengus L., and saithe, Pollachius virens L.

Endurance and swimming speed were measured in mackerel, herring and saithe when they were induced by the optomotor response to swim at prolonged speeds along a 28-m circular track through still water in a 10-m diameter gantry tank. The maximum sustained swimming speed ( U _ms was measured as body lengths per second ( b.l.s ⁻¹) for each species and for saithe of different size groups. Herring with U _ms of 4.06 b.l.s ⁻¹ (25.3 cm, 13.5°C) were the fastest, mackerel U _ms was 3.5 b.l.s ¹ (33 cm, 11.7°C) and saithe (14.4°C) showed a size effect where U _ms at 25 cm was 3.5 b.l.s ¹ and at 50 cm 2.2 b.l.s ¹. When swimming at speeds higher that U _ms, all three species showed reduced endurance as speed increased. How the curved track reduces the swimming speed is discussed.     

高原鼠兔氧比传导特征的实验研究

本实验采用国外新近提出的一项能综合评价机体气体交换系统中各氧降阶差时运氧能力的适应水平高低的重要指标──氧比传导（ＭＯ２－ＳＣ）,研究了高原鼠兔气体交换系统运氧能力的低氧适应特征及规律。结果表明,对照条件下,在吸入气（Ｉ）至肺泡气（Ａ）（Ｉ→Ａ）、Ａ至动脉血（ａ）（Ａ→ａ）、ａ至混合静脉血（ｖ）（ａ→ｖ）及Ｉ→ｖ各阶差中,以Ａ→ａ的ＭＯ２－ＳＣ运氧能力最大。低氧１５ｍｍ后,Ｉ→Ａ及ａ→ｖ的ＭＯ２－ＳＣ均显著升高,并以Ｉ→Ａ增加最为显著,该水平运氧能力是对照的２倍,增长１２０．９％;而Ａ→ａ及Ｉ→ｖＭＯ２－ＳＣ变化无显著性差异。低氧３０ｍｉｎ时,Ｉ→Ａ的ＭＯ２－ＳＣ继续显著增长,运氧能力是对照的２．７倍,增长１７０．７％,其余３个氧降阶差的ＭＯ２－ＳＣ无显著性改变。以上结果表明,高原鼠兔低氧代偿贮备较大,尤以肺泡气至动脉血阶差最为重要,而通气氧传导能力的增强也是高原鼠兔低氧适应的主要原因。     

Discovery of 4′-OH-flurbiprofen Mannich base derivatives as potential Alzheimer’s disease treatment with multiple inhibitory activities

A series of 4′-OH flurbiprofen Mannich base derivatives were designed, synthesized and evaluated as potential multifunctional agents for the treatment of Alzheimer’s disease. The biological screening results indicated that most of these derivatives exhibited good multifunctional activities. Among them, compound 8n demonstrated the best inhibitory effects on self-induced Aβ_1-42 aggregation (65.03% at 25.0?μM). Moreover, this representative compound also exhibited good antioxidant activity, biometal chelating ability and anti-neuroinflammatory activity in vitro. Furthermore, compound 8n displayed appropriate blood-brain barrier permeability. These multifunctional properties highlight compound 8n as promising candidate for further development of multi-functional drugs against AD.     

嗜盐噬菌弧菌BALOs10菌株的分离、鉴定及其裂解谱

【目的】从海水中分离得到蛭弧菌类群(Bdellovibrio-and-likeorganisms,BALOs)新型菌株,丰富BALOs的种质资源。【方法】从中国深圳大亚湾取回海水样品后,使用本实验室分离得到的Vibrio alginolyticus LF TCBS 15作为宿主,通过海水双层平板法分离得到BALOs菌株,通过光学显微镜及透射电镜观察菌体形态,对16S rDNA序列进行系统发育分析,完成分子鉴定。采用双层平板滤纸片法分析NaCl浓度、pH及温度对菌株BALOs10生长的影响并测定菌株BALOs10对16株细菌的裂解效果。【结果】成功分离出一株以Vibrio alginolyticus LF TCBS 15为宿主的BALOs菌株BALOs10。噬菌斑呈圆形、透明且边缘光滑整齐,菌体为弧状,极生单鞭毛,菌体大小(0.21–0.44)μm×(1.25–1.87)μm。菌株最佳生长温度、NaCl浓度和pH范围分别为35–37°C、2%–3%(W/V)和7–8。菌株BALOs10可以裂解9株不同种的受试菌,占总试验菌株数(16株)的56.3%,主要是海杆菌属和弧菌属;菌株BALOs10的16S rDNA与最相近的典型菌株Halobacteriovorax marinus SJ的相似性只有92.14%,可能是一个全新的物种,将其命名为Halobacteriovorax sp. BALOs10。【结论】本文研究发现了Halobacteriovorax属(嗜盐噬菌弧菌属)的一个新型菌株,丰富了BALOs种质资源,为后续的应用及理论研究奠定物质基础。     

艾比湖湿地芦苇根际土壤氨氧化古菌的多样性和群落结构

【目的】旨在揭示耐盐植物芦苇根际与非根际土壤AOA群落结构间的差异,为深入研究盐生植物根际土壤微生物与耐盐性之间的关系提供理论基础。【方法】应用高通量测序技术以氨单加氧酶基因(amoA)为分子标记,对新疆艾比湖湿地荒漠生态系统不同季节(春、夏、秋)芦苇根际与非根际土壤氨氧化古菌(AOA)的多样性和群落结构进行研究。【结果】结果表明,不同季节芦苇根际土壤AOA多样性和丰富度存在差异,相比非根际土壤,夏季和秋季芦苇根际土壤AOA多样性较低丰富度较高,春季多样性较高丰富度较低。芦苇根际土壤中AOA的多样性为春季夏季秋季。AOA群落组成分析表明,土壤样品中AOA群落主要集中在泉古菌门(Crenarchaeota)和奇古菌门(Thaumarchaeota),其中泉古菌门为主要优势菌门。RDA分析表明,含水量(SM)、有机质(SOM)、总氮(TN)和pH是影响芦苇根际土壤AOA群落多样性和丰富度的主要环境因子。【结论】不同季节芦苇根际土壤AOA多样性及丰富度存在差异,相比非根际土壤,芦苇根际土壤AOA更丰富。