Role of miR-1 and miR-133a in myocardial ischemic postconditioning

Background  

Ischemic postconditioning (IPost) has aroused much attention since 2003 when it was firstly reported. The role of microRNAs (miRNAs or miRs) in IPost has rarely been reported. The present study was undertaken to investigate whether miRNAs were involved in the protective effect of IPost against myocardial ischemia-reperfusion (IR) injury and the probable mechanisms involved.     

Knockdown of SPARC leads to decreased cell-cell adhesion and lens cataracts during post-gastrula development in Xenopus laevis

SPARC is a multifunctional matricellular glycoprotein with complex, transient tissue distribution during embryonic development. In Xenopus laevis embryos, zygotic activation of SPARC is first detected during late gastrulation, undergoing rapid changes in its spatiotemporal distribution throughout organogenesis. Injections of anti-sense Xenopus SPARC morpholinos (XSMOs) into 2- and 4-cell embryos led to a dose-dependent dissociation of embryos during neurula and tailbud stages of development. Animal cap explants derived from XSMO-injected embryos also dissociated, resulting in the formation of amorphous ciliated microspheres. At low doses of XSMOs, lens cataracts were formed, phenocopying that observed in Sparc-null mice. At XSMOs concentrations that did not result in a loss of axial tissue integrity, adhesion between myotomes at intersomitic borders was compromised with a reduction in SPARC concentration. The combined data suggest a critical requirement for SPARC during post-gastrula development in Xenopus embryos and that SPARC, directly or indirectly, promotes cell?Ccell adhesion in vivo.     

Molecular identification of endophytic fungi from medicinal plant <Emphasis Type="Italic">Huperzia serrata</Emphasis> based on rDNA ITS analysis

Fifty-two endophytic fungi strains with different colony morphologies were isolated from stems, leaves and roots of Huperzia serrata (Thunb. ex Murray) Trevis. collected from Bawangling Reserve of Hainan Province in southern China. They were identified mainly based on rDNA ITS sequences and phylogenetic analysis. The results showed that all strains belonged to four classes, i.e. Sordariomycetes (92.31%), Dothideomycetes (3.85%), Pezizomycetes (1.92%) and Agaricomycetes (1.92%). Forty-seven strains were identified at the genus level, including Glomerella (Colletotrichum), Hypocrea (Trichoderma), Pleurostoma, Chaetomium, Coniochaeta (Lecythophora), Daldinia, Xylaria, Hypoxylon, Nodulisporium, Cazia and Phellinus. As to the other five strains, three were identified at the order level and two at the family level, indicating that a great diversity of fungi taxa exists in H. serrata. Most isolated strains belonged to the genus of Glomerella (Colletotrichum) and Hypoxylon, twenty-one from Glomerella and its anamorph Colletotrichum (42.3% of total isolated strains) and ten from Hypoxylon (19.2% of total isolated strains). Pleurostoma, Chaetomium, Coniochaeta (Lecythophora), Daldinia, Xylaria, Hypoxylon, Nodulisporium, Cazia and Phellinus were reported as endophytic fungi isolated from H. serrata for the first time.     

Roles of Bcl-2 family members,PI3K and NF-κB pathways in <Emphasis Type="Italic">Escherichia coli</Emphasis>-induced apoptosis in human monocytic U937 cells

We previously showed that infection of human monocytic U937 cells with nonpathogenic Escherichia coli (E. coli) induced rapid apoptosis in a dose- and time-dependent manner. We also found that E. coli increase p38 mitogen-activated protein Kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK), and decrease extracellular-Regulated Kinase1/2 (ERK1/2) phosphorylation and increase caspase-3 and -9 activity in U937 cells. The current study determines if Bcl-2, Bax, the phosphatidylinositol 3-kinase (PI3K)/Akt and nuclear factor kappa B (NF-κB) regulates E. coli–induced U937 cell apoptosis. Studying the underlying mechanisms we found that the E. coli-induced apoptosis in U937 cells was associated with a more prominent reduction in expression of Bcl-2, levels of P-Akt and NF-κB. Because levels of inhibition of apoptosis protein (cIAP), and X-chromosomelinked inhibitor of apoptosis protein (XIAP) are regulated by NF-κB, E. coli decreased the levels of these proteins in U937 cells through inhibition of NF-κB. Moreover, E. coli markedly elevated Bax expression and cytochrome c redistribution. LY294002, PDTC and Embelin, specific inhibitors of PI3K, NF-κB and XIAP, induced U937 cell apoptosis and the apoptosis is dependent on activity of caspase-3 and -9 in E. coli-treated U937 cells. Through using LY294002 and western blotting, we identified NF-κB was the downstream Akt target regulated by E. coli. Taken together, these results clearly indicate reduced activation of NF-κB via impaired PI3K/Akt activation could result in increased apoptosis of U937 cells infected by E. coli. Moreover, E. coli can induce apoptosis with an increased expression of Bax and a reduced expression of Bcl-2, which resulted in increased levels of cytochrome c release and increase caspase-3 and -9 in U937 cells.     

Efficient salt removal in a continuously operated upflow microbial desalination cell with an air cathode

Microbial desalination cells (MDCs) hold great promise for drinking water production because of potential energy savings during the desalination process. In this study, we developed a continuously operated MDC - upflow microbial desalination cell (UMDC) for the purpose of salt removal. During the 4-month operation, the UMDC constantly removed salts and generated bio-electricity. At a hydraulic retention time (HRT) of 4 days (salt solution) and current production of ∼62 mA, the UMDC was able to remove more than 99% of NaCl from the salt solution that had an initial salt concentration of 30 g total dissolved solids (TDS)/L. In addition, the TDS removal rate was 7.50 g TDS L⁻¹ d⁻¹ (salt solution volume) or 5.25 g TDS L⁻¹ d⁻¹ (wastewater volume), and the desalinated water met the drinking water standard, in terms of TDS concentration. A high charge transfer efficiency of 98.6% or 81% was achieved at HRT 1 or 4 d. The UMDC produced a maximum power density of 30.8 W/m³. The phenomena of bipolar electrodialysis and proton transport in the UMDC were discussed. These results demonstrated the potential of the UMDC as either a sole desalination process or a pre-desalination reactor for downstream desalination processes.     

乳糖酶研究进展

乳糖酶作为乳品添加剂,应用相当广泛,通过来源及其性质、基础研究和应用等方面对乳糖酶进行综述,重点介绍乳糖酶研究上的新进展和应用的新领域,由于近年来低温乳糖酶成为研究热点,特别对低温乳糖酶的研究进行介绍.     

杜鹃花属植物扦插繁殖研究进展

我国有着丰富的杜鹃花资源,但有关其繁殖应用的研究还具有一定的局限。种子育苗耗时长,组培育苗成本和技术要求高,都不适于杜鹃花属植物的大面积生产。扦插繁殖快,还可保持母本的优良性状。从插条的选择,准备,插条的生根激素处理,扦插基质的选择,外界环境条件对扦插成活率的影响及扦插后的养护管理等六个方面对杜鹃的扦插繁殖技术的研究进行综述,以期推进杜鹃花属植物,尤其是中国野生杜鹃的引种驯化和大面积的推广应用。     

紫花地丁HPLC指纹图谱研究

目的:建立紫花地丁药材HPLC指纹图谱,提供药材质量控制的可靠方法。方法:采用HPLC方法,以Agi-lent C18(4.6 mm×250 mm,5μm)为色谱柱,甲醇-0.5%醋酸水溶液进行梯度洗脱;检测波长353 nm,流速1.0mL/min。结果:检测了12批不同来源的紫花地丁药材,确立了18个共有峰,建立了紫花地丁对照指纹图谱,计算各被测样品的HPLC指纹图谱的整体相似度,并指认了菊苣苷、七叶内酯、东莨菪素、早开堇菜苷4个特征峰,比较了上述成分在不同药材中的含量。结论:所建立的指纹图谱具有良好的精密度、重现性和稳定性,可作为紫花地丁药材质量控制标准。     

NF-κB介导非对称性二甲基精氨酸上调大鼠主动脉诱导型一氧化氮合酶的表达

目的探讨非对称性二甲基精氨酸(ADMA)上调大鼠主动脉诱导型一氧化氮合酶(iNOS)的表达是否是通过激活NF-κB实现的。方法 Wistar大鼠50只随机分为四组:①对照组(n=10):标准饲料喂养。②H组(n=12):高脂饲料喂养。③A+H组(n=14):予ADMA[0.2mg/kgd]灌胃,高脂饲料喂养。④P+A+H组(n=14):予吡咯烷二硫代氨基甲酸盐(pyrrolidine dithiocarbamate,PDTC)[40mg/kgd]腹腔注射、ADMA[0.2mg/kgd]灌胃、高脂饲料喂养。对照组、H组予等体积的生理盐水灌胃及腹腔注射、A+H组给予等体积的生理盐水腹腔注射。18周后麻醉大鼠、取主动脉。以实时荧光定量PCR和Westen blotting分别检测iNOS mRNA和蛋白表达,以电泳迁移率变动分析(EMSA)和增强化学发光法(ECL)检测NF-κB活性。结果①A+H组iNOS mRNA和蛋白表达量较对照组和H组增加(P<0.05),P+A+H组较A+H组iNOSmRNA和蛋白表达量降低(P<0.05)。②A+H组NF-κB活性较对照组和H组显著升高(P<0.05),P+A+H组NF-κB活性较A+H组明显降低(P<0.05)③相关分析:NF-κB活性与iNOS mRNA和蛋白表达量呈正相关(相关系数r分别为0.854、0.876,P<0.05)。结论 ADMA可能通过激活NF-κB途径上调iNOS表达,从而促进动脉粥样硬化的发生发展。