A viral vector expressing hypoxia-inducible factor 1 alpha inhibits hippocampal neuronal apoptosis

Hypoxia-inducible factor 1 （HIF-1） attenuates amyloid-beta protein neurotoxicity and decreases apoptosis induced by oxidative stress or hypoxia in cortical neurons. In this study, we construct-ed a recombinant adeno-associated virus （rAAV） vector expressing the human HIF-1αgene （rAAV-HIF-1α）, and tested the assumption that rAAV-HIF-1αrepresses hippocampal neuronal apoptosis induced by amyloid-beta protein. Our results conifrmed that rAAV-HIF-1αsigniifcant-ly reduces apoptosis induced by amyloid-beta protein in primary cultured hippocampal neurons. Direct intracerebral rAAV-HIF-1αadministration also induced robust and prolonged HIF-1αproduction in rat hippocampus. Single rAAV-HIF-1αadministration resulted in decreased apoptosis of hippocampal neurons in an Alzheimer＇s disease rat model established by intrace-rebroventricular injection of aggregated amyloid-beta protein （25-35）. Our in vitro and in vivo ifndings demonstrate that HIF-1 has potential for attenuating hippocampal neuronal apoptosis induced by amyloid-beta protein, and provides experimental support for treatment of neurode-generative diseases using gene therapy.

Nucleoprotein-based indirect enzyme-linked immunosorbent assay(indirect ELISA) for detecting antibodies specific to Ebola virus and Marbug virus

Full-length nucleoproteins from Ebola and Marburg viruses were expressed as His-tagged recombinant proteins in Escherichia coli and nucleoprotein-based enzyme-linked immunosorbent assays(ELISAs) were established for the detection of antibodies specific to Ebola and Marburg viruses. The ELISAs were evaluated by testing antisera collected from rabbit immunized with Ebola and Marburg virus nucleoproteins. Although little cross-reactivity of antibodies was observed in antiEbola virus nucleoprotein rabbit antisera, the highest reactions to immunoglobulin G(Ig G) were uniformly detected against the nucleoprotein antigens of homologous viruses. We further evaluated the ELISA's ability to detect antibodies to Ebola and Marburg viruses using human sera samples collected from individuals passing through the Guangdong port of entry. With a threshold set at the mean plus three standard deviations of average optical densities of sera tested, the ELISA systems using these two recombinant nucleoproteins have good sensitivity and specificity. These results demonstrate the usefulness of ELISA for diagnostics as well as ecological and serosurvey studies of Ebola and Marburg virus infection.

Pharmacokinetics,distribution,and excretion of sodium oligomannate,a recently approved anti-Alzheimer's disease drug in China

The National Medical Products Administration has authorized sodium oligomannate for treating mild-to-moderate Alzheimer’s disease.In this study,an LC-MS/MS method was developed and validated to quantitate sodium oligomannate in different biomatrices.The plasma pharmacokinetics,tissue distribution,and excretion of sodium oligomannate in Sprague-Dawley rats and beagle dogs were systematically investigated.Despite its complicated structural composition,the absorption,distribution,metabolism,and excretion profiles of the oligosaccharides in sodium oligomannate of different sizes and terminal derivatives were indiscriminate.Sodium oligomannate mainly crossed the gastrointestinal epithelium through paracellular transport following oral administration,with very low oral bioavailability in rats(0.6%-1.6%)and dogs(4.5%-9.3%).Absorbed sodium oligomannate mainly resided in circulating body fluids in free form with minimal distribution into erythrocytes and major tissues.Sodium oligomannate could penetrate the blood-cerebrospinal fluid(CSF)barrier of rats,showing a constant area under the concentration-time curve ratio(CSF/plasma)of approximately 5%.The cumulative urinary excretion of sodium oligomannate was commensurate with its oral bioavailability,supporting that excretion was predominantly renal,whereas no obvious biliary secretion was observed following a single oral dose to bile duct-cannulated rats.Moreover,only 33.7%(male)and 26.3%(female)of the oral dose were recovered in the rat excreta within 96 h following a single oral administration,suggesting that the intestinal flora may have ingested a portion of unabsorbed sodium oligomannate as a nutrient.

N-glycans released from glycoproteins using a commercial kit and comprehensively analyzed with a hypothetical database

The glycosylation of proteins is responsible for their structural and functional roles in many cellular activities.This work describes a strategy that combines an efficient release, labeling and liquid chromatography–mass spectral analysis with the use of a comprehensive database to analyze N-glycans. The analytical method described relies on a recently commercialized kit in which quick deglycosylation is followed by rapid labeling and cleanup of labeled glycans. This greatly improves the separation, mass spectrometry（MS） analysis and fluorescence detection of N-glycans. A hypothetical database, constructed using Glyc Resoft, provides all compositional possibilities of N-glycans based on the common sugar residues found in N-glycans. In the initial version this database contains ＆gt; 8,700 N-glycans, and is compatible with MS instrument software and expandable. N-glycans from four different well-studied glycoproteins were analyzed by this strategy. The results provided much more accurate and comprehensive data than that had been previously reported. This strategy was then used to analyze the N-glycans present on the membrane glycoproteins of gastric carcinoma cells with different degrees of differentiation. Accurate and comprehensive N-glycan data from those cells was obtained efficiently and their differences were compared corresponding to their differentiation states. Thus, the novel strategy developed greatly improves accuracy, efficiency and comprehensiveness of N-glycan analysis.