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Glycosylation is one of the most common eukaryotic post-translational modifications, and aberrant glycosylation has been linked to many diseases. However, glycosylation and glycome analysis is a significantly challenging task. Although several lines of evidence have indicated that protein glycosylation is defective in Alzheimer's disease (AD), only a few studies have focused on AD glycomics. The etiology of AD is unclear and there are no effective disease-modifying treatments for AD. In this study, we found that the object recognition memory, passive avoidance, and spatial learning and memory of senescence-accelerated mouse prone 8 (SAMP8) strain, an AD animal model, were deficient, and LW-AFC, which was prepared from the traditional Chinese medicine prescription Liuwei Dihuang decoction, showed beneficial effects on the deterioration of cognitive capability in SAMP8 mice. Forty-three and 56 N-glycan were identified in the cerebral cortex and serum of SAMP8 mice, respectively. The N-glycan profile in SAMP8 mice was significantly different from that of senescence accelerated mouse resistant 1 (SAMR1) strains, the control of SAMP8 mice. Treatment with LW-AFC modulated the abundance of 21 and 6 N-glycan in the cerebral cortex and serum of SAMP8 mice, respectively. The abundance of (Hex)3(HexNAc)5(Fuc)1(Neu5Ac)1 and (Hex)2(HexNAc)4 decreased in the cerebral cortex and serum of SAMP8 mice compared with SAMR1 mice, decreases that were significantly correlated with learning and memory measures. The administration of LW-AFC could reverse or increase these levels in SAMP8 mice. These results indicated that the effects of LW-AFC on cognitive impairments in SAMP8 mice might be through modulation of N-glycan patterns, and LW-AFC may be a potential anti-AD agent. [ABSTRACT FROM AUTHOR]

Objective: Synaptic vesicles (SVs) are essential organelles that store and release neurotransmitters within presynaptic terminals. Isolated and purified SVs can be used to investigate their biochemical, structural, and functional characteristics, to elucidate the neurotransmission process. This paper describes a method for obtaining purified and functional SVs. Methods: SVs were isolated from the brains of Sprague--Dawley rats using differential and density-gradient centrifugation. Their morphology was observed with electron microscopy. The amount of protein in the SV fraction was determined by the Bradford assay. Specific SVs were purified using magnetic beads and immunoisolation, and immunoblot assays were used to measure levels of SV markers. SV glutamate uptake was assayed by radiotracer efflux assays. Results: A total of 10 mg SV protein was purified from 22 g of hippocampal and cerebral cortex tissue. The purified SVs were homogenous small spherical vesicles with a diameter of ~40 nm as assessed with electron microscopy, and they were rich in the protein SV protein 2 (SV2), vesicular glutamate transporter 1 (VGLUT1), and VGLUT2, but not VGLUT3. The SV2-specific SVs obtained by immunoadsorption with nearly 83% yield could uptake L- glutamate. Rose Bengal, a VGLUT inhibitor, prevented SV2-specific SVs from taking-up L- glutamate. Conclusions: This study describes a successful method for obtaining purified SVs that retained their structure and ability to perform their primary in vivo functions. These SVs can be used to understand SV composition and function, and the process of neurotransmitter release, and to evaluate therapeutic drugs for nervous system diseases. [ABSTRACT FROM AUTHOR]

The senescence-accelerated mouse prone 8 (SAMP8) strain is considered a robust experimental model for developing preventative and therapeutic treatments for Alzheimer's disease (AD), a neurodegenerative disease which cannot be effectively prevented, halted, or cured. Our previous studies showed that LW-AFC, a new formula derived from the classical traditional Chinese medicinal prescription Liuwei Dihuang decoction, ameliorates cognitive deterioration in PrP-hAβPPswe/PS1ΔE9 transgenic mice and SAMP8 mice. This study aims to investigate the mechanism that mediates how LW-AFC improves cognitive deficit on the basis of the transcriptome. We conducted a genome-wide survey of gene expression in the hippocampus in mice from the senescence accelerated mouse resistant 1 (SAMR1) strain, from SAMP8 and from LW-AFC treated SAMP8. The results showed that LW-AFC reversed the transcriptome in the hippocampus of SAMP8 mice. The specific investigation of altered gene expression in subtypes defined by cognitive profiles indicated that the systemic lupus erythematosus pathway, spliceosomes, amyotrophic lateral sclerosis, and the insulin signaling were involved in the improvement of cognitive ability by LW-AFC. The expression of genes Enpp2, Etnk1, Epdr1, and Gm5900 in the hippocampus were correlated with that of LW-AFC's ameliorating cognitive impairment in SAMP8 mice. Because LW-AFC is composed of polysaccharides, glycosides, and oligosaccharides, we infer that LW-AFC has direct or indirect effects on altering gene expressions and regulating pathways in the hippocampus of SAMP8 mice. These data are helpful for the enhanced identification of LW-AFC as new therapeutic modalities to AD. [ABSTRACT FROM AUTHOR]