Abeta Protein Research Articles

Differential patterns of lysosomal dysfunction are seen in the clinicopathological forms of primary progressive aphasia.

Increasing evidence implicates endo-lysosomal dysfunction in frontotemporal dementia (FTD). 18 proteins were quantified using a mass spectrometry assay panel in the cerebrospinal fluid of 36 people with the language variant of FTD, primary progressive aphasia (PPA) (including 13 with non-fluent variant (nfvPPA), 11 with semantic variant (svPPA), and 12 with logopenic variant (lvPPA)) and 19 healthy controls. The concentrations of the cathepsins (B, D, F, L1, and Z) as well as AP-2 complex subunit beta, ganglioside GM2 activator, beta-hexosaminidase subunit beta, tissue alpha L-fucosidase, and ubiquitin were decreased in nfvPPA compared with controls. In contrast, the concentrations of amyloid beta A4 protein, cathepsin Z, and dipeptidyl peptidase 2 were decreased in svPPA compared with controls. No proteins were abnormal in lvPPA. These results indicate a differential alteration of lysosomal proteins in the PPA variants, suggesting those with non-Alzheimer's pathologies are more likely to show abnormal lysosomal function.

Increased Angiogenesis by Exosomes Secreted by Adipose-Derived Stem Cells upon Lipopolysaccharide Stimulation.

Exosomes secreted by adipose-derived stem cells (ADSCs) enhance angiogenesis and wound healing. However, in clinical settings, wounds may be infected by various bacteria or pathogens. We investigated whether human ADSCs stimulated with lipopolysaccharide (LPS) secrete exosomes (ADSC-LPS-exo) that augment the angiogenesis of human umbilical vein endothelial cells (HUVECs). ExoQuick-TC exosome precipitation solution was used to purify exosomes from human ADSC culture media in the presence or absence of 1 µg/mL LPS treatment for 24 h. The uptake of ADSC-LPS-exo significantly induced the activation of cAMP response element binding protein (CREB), activating protein 1 (AP-1), and nuclear factor-κB (NF-κB) signaling pathways and increased the migration of and tube formation in HUVECs. RNA interference with CREB, AP-1, or NF-κB1 significantly reduced the migration of and tube formation in HUVECs treated with ADSC-LPS-exo. An experiment with an antibody array for 25 angiogenesis-related proteins revealed that only interleukin-8 expression was significantly upregulated in HUVECs treated with ADSC-LPS-exo. In addition, proteomic analysis revealed that eukaryotic translation initiation factor 4E, amyloid beta A4 protein, integrin beta-1, and ras-related C3 botulinum toxin substrate 1 may be potential candidates involved in ADSC-LPS-exo-mediated enhanced angiogenesis.

Novel circulating protein biomarkers for thyroid cancer determined through data-independent acquisition mass spectrometry.

BackgroundDistinguishing between different types of thyroid cancers (TC) remains challenging in clinical laboratories. As different tumor types require different clinical interventions, it is necessary to establish new methods for accurate diagnosis of TC.MethodsProteomic analysis of the human serum was performed through data-independent acquisition mass spectrometry for 29 patients with TC (stages I–IV): 13 cases of papillary TC (PTC), 10 cases of medullary TC (MTC), and six cases follicular TC (FTC). In addition, 15 patients with benign thyroid nodules (TNs) and 10 healthy controls (HCs) were included in this study. Subsequently, 17 differentially expressed proteins were identified in 291 patients with TC, including 247 with PTC, 38 with MTC, and six with FTC, and 69 patients with benign TNs and 176 with HC, using enzyme-linked immunosorbent assays.ResultsIn total, 517 proteins were detected in the serum samples using an Orbitrap Q-Exactive-plus mass spectrometer. The amyloid beta A4 protein, apolipoprotein A-IV, gelsolin, contactin-1, gamma-glutamyl hydrolase, and complement factor H-related protein 1 (CFHR1) were selected for further analysis. The median serum CFHR1 levels were significantly higher in the MTC and FTC groups than in the PTC and control groups (P < 0.001). CFHR1 exhibited higher diagnostic performance in distinguishing patients with MTC from those with PTC (P < 0.001), with a sensitivity of 100.0%, specificity of 85.08%, area under the curve of 0.93, and detection cut-off of 0.92 ng/mL.ConclusionCFHR1 may serve as a novel biomarker to distinguish PTC from MTC with high sensitivity and specificity.

Role of Cholesterol on Binding of Amyloid Fibrils with Lipid Bilayers

The aggregation of amyloid-beta proteins into soluble oligomers and fibril deposits is believed to trigger the molecular processes accounting for Alzheimer's disease. In addition, levels of cholesterol, which is an important component of the neuron plasma membrane, are elevated in the brain of Alzheimer's patients and they correlate with the development of the disease in mid-life individuals. A possible explanations for this correlation is that cholesterol affects binding of Abeta proteins to lipid bilayer as this process was shown to have a deleterious effect on neurons. Accordingly, experimental studies have shown that amyloid-beta fibrils bind more strongly to lipid bilayers containing higher cholesterol levels. The molecular mechanism of the process is, however, not well understood. Here, we perform extensive molecular dynamics simulations to investigate the role of cholesterol on fibril-bilayer binding. In particular, we compute the number of binding events as a function of cholesterol level. We find that binding events are driven by electrostatic interactions, they have a longer life-time and occur more frequently with increased cholesterol level. An explanation of these results at the molecular level is provided based on the distribution of residues on the fibril surface.

Common Neurodegeneration-Associated Proteins Are Physiologically Expressed by Human B Lymphocytes and Are Interconnected via the Inflammation/Autophagy-Related Proteins TRAF6 and SQSTM1.

There is circumstantial evidence that, under neurodegenerative conditions, peptides deriving from aggregated or misfolded specific proteins elicit adaptive immune responses. On another hand, several genes involved in familial forms of neurodegenerative diseases exert key innate immune functions. However, whether or not such observations are causally linked remains unknown. To start addressing this issue, we followed a systems biology strategy based on the mining of large proteomics and immunopeptidomics databases. First, we retrieved the expression patterns of common neurodegeneration-associated proteins in two professional antigen-presenting cells, namely B lymphocytes and dendritic cells. Surprisingly, we found that under physiological conditions, numerous neurodegeneration-associated proteins are abundantly expressed by human B lymphocytes. A survey of the human proteome allowed us to map a unique protein-protein interaction network linking common neurodegeneration-associated proteins and their first shell interactors in human B lymphocytes. Interestingly, network connectivity analysis identified two major hubs that both relate with inflammation and autophagy, namely TRAF6 (TNF Receptor Associated Factor 6) and SQSTM1 (Sequestosome-1). Moreover, the mapped network in B lymphocytes comprised two additional hub proteins involved in both inflammation and autoimmunity: HSPA8 (Heat Shock Protein Family A Member 8 also known as HSC70) and HSP90AA1 (Heat Shock Protein 90 Alpha Family Class A Member 1). Based on these results, we then explored the Immune Epitope Database “IEDB-AR” and actually found that a large share of neurodegeneration-associated proteins were previously reported to provide endogenous MHC class II-binding peptides in human B lymphocytes. Of note, peptides deriving from amyloid beta A4 protein, sequestosome-1 or profilin-1 were reported to bind multiple allele-specific MHC class II molecules. In contrast, peptides deriving from microtubule-associated protein tau, presenilin 2 and serine/threonine-protein kinase TBK1 were exclusively reported to bind MHC molecules encoded by the HLA-DRB1 1501 allele, a recently-identified susceptibility gene for late onset Alzheimer's disease. Finally, we observed that the whole list of proteins reported to provide endogenous MHC class II-binding peptides in human B lymphocytes is specifically enriched in neurodegeneration-associated proteins. Overall, our work indicates that immunization against neurodegeneration-associated proteins might be a physiological process which is shaped, at least in part, by B lymphocytes.

Modulation of Proteome Profile in AβPP/PS1 Mice Hippocampus, Medial Prefrontal Cortex, and Striatum by Palm Oil Derived Tocotrienol-Rich Fraction.

Tocotrienol-rich fraction (TRF) is a mixture of vitamin E analogs derived from palm oil. We previously demonstrated that supplementation with TRF improved cognitive function and modulated amyloid pathology in AβPP/PS1 mice brains. The current study was designed to examine proteomic profiles underlying the therapeutic effect of TRF in the brain. Proteomic analyses were performed on samples of hippocampus, medial prefrontal cortex (mPFC), and striatum using liquid chromatography coupled to Q Exactive HF Orbitrap mass spectrometry. From these analyses, we profiled a total of 5,847 proteins of which 155 proteins were differentially expressed between AβPP/PS1 and wild-type mice. TRF supplementation of these mice altered the expression of 255 proteins in the hippocampus, mPFC, and striatum. TRF also negatively modulated the expression of amyloid beta A4 protein and receptor-type tyrosine-protein phosphatase alpha protein in the hippocampus. The expression of proteins in metabolic pathways, oxidative phosphorylation, and those involved in Alzheimer’s disease were altered in the brains of AβPP/PS1 mice that received TRF supplementation.

Behavioral and molecular markers of death in Drosophila melanogaster.

Fly movement was tracked through 3-dimensional (3D) space as the fly died, using either reflected visible light, reflected infrared (IR) light, or fly GFP fluorescence. Behaviors measured included centrophobism, negative geotaxis, velocity, and total activity. In addition, frequency of directional heading changes (FDHC) was calculated as a measure of erratic movement. Nine middle-aged flies were tracked as they died during normal aging, and fifteen young flies were tracked as they died from dehydration/starvation stress. Episodes of increased FDHC were observed 0-8 h prior to death for the majority of the flies. FDHC was also increased with age in flies with neuronal expression of a human Abeta42 protein fragment associated with Alzheimer's disease. Finally, green autofluorescence appeared in the eye and body immediately prior to and coincident with death, and fluorescence of GFP targeted to the retina increased immediately prior to and coincident with death. The results suggest the potential utility of FDHC, green autofluorescence, and retinal GFP as markers of neuronal malfunction and imminent death.

C-61 The Molecular Basis of Autism, Amyloid Precursor Protein, and its Relevance to Neuropsychology: Case Study and Neuropathology of Boy with Autism

Abstract Objective Andrew (pseudoname) a boy with severe autism, participated in autism research at Indiana University School of Medicine. Andrew suddenly died in his sleep and his family donated his brain for further study at our institution. This case sparks the proposed discussion of the latest molecular underpinnings of autism which have been localized to genetic abnormalities at the synapse and in gene expression (translation and transcription). These mechanisms contribute to macrocephaly and microcephaly which are overrepresented in autism. The broad objective of this discussion will be to associate the molecular underpinnings of autism to brain anatomy and neuropsychological function. The specific aim will be to report results of Andrew's available psychological testing, plasma amyloid precursor protein (APP) profile, MRI volumetry, and neuropathological findings. Our published reports of APP profiles in plasma and brain tissue also will be reviewed. Method Andrew was a 13 yr old boy with severe autism (CARS-60), medically refractory seizures, and intellectual deficiency (MSEL49). The patient showed significant regression in speech (400 words down to 2) from age 5 to 13. He died from a presumptive seizure. Results Andrew's MRI volumetry showed increased white matter, including the left temporal lobe; neuropathology was significant for enlarged brain with cortical dysplasia. APP profile showed increased sAPPalpha with low ABeta protein, similar to what we reported in plasma and brain tissue studies. Conclusions Andrew is among the 20% of children with autism with macrocephaly with white &gt;gray matter. Molecular underpinnings in relation to this finding and to the neuropsychology of autism will be discussed.

Frequent involvement of the amyloid pathway in prodromal dementia with Lewy bodies

Lewy body dementia (LBD) is the most frequent of the degenerative dementias, after Alzheimer's disease. To analyse the core biomarkers of Alzheimer's disease in the cerebrospinal fluid of exclusively Hispanic patients with prodromal LBD, in order to determine whether there is involvement of the amyloid pathway or the tau pathway. Between 2008 and 2017 we included 430 patients with mild cognitive impairment according to Petersen criteria, from three hospitals in the province of Alicante. They underwent clinical check-ups every 6-12 months to evaluate their clinical stability or their progression to dementia using current clinical criteria. Among other complementary tests, biomarkers for Alzheimer's disease in the cerebrospinal fluid were analysed. Of all the patients included, 26 developed LBD and 29 remained stable for at least five years, and were thus considered as a reference. In this group only five (17%) had Abeta(1-42) protein values below normal, whereas 16 (55%) of the patients with LBD had altered levels. No differences were found in the levels of tau protein. On comparing the LBD groups with and without amyloidosis, differences were only found in the levels of Abeta(1-42) protein. We highlight the frequent presence of amyloid pathology in prodromal LBD in our population, and the probable involvement of different metabolic pathways in the same clinically defined dementia.

L‐proline and betaine inhibit extracellular enzymes mediated abeta 1‐42 aggregation, oxidative stress, and toxicity

AbstractExtracellular amyloid plaques are characteristics of Alzheimer's disease (AD). The amyloid plaques mainly consist of amyloid‐β (abeta) fragments. Extracellular biomolecules play a key role in abeta aggregation and subsequent plaque formation during AD. Among them, extracellular enzymes are known to induce abeta aggregation by catalyzing the crosslinking of abeta proteins. Although several therapeutic strategies have been studied to combat AD, studies to treat extracellular enzymes mediated abeta aggregation and toxicity is not explored in detail yet. Here we study the potential of osmolyte molecules l‐proline and betaine to inhibit the abeta aggregation and toxicity promoted by extracellular enzymes transglutaminase and lysyl oxidase in vitro. Results reveal that l‐proline and betaine have the potential to inhibit extracellular matrix enzymes mediated abeta aggregation/fibril formation and toxicity and oxidative stress in brain endothelial cells. Hence osmolytes could have the potential to modulate the effects of extracellular molecules during AD.

Effects of Gardenia jasminoides extracts on cognition and innate immune response in an adult Drosophila model of Alzheimer's disease

Herbal extracts have been extensively used worldwide for their application on memory improvement, especially among aged and memory-deficit populations. In the present study, the memory loss induced by human Abeta protein over-expression in fruitfly Alzheimer's disease (AD) model was rescued by multiple extracts from Gardenia jasminoides. Three extracts that rich with gardenia yellow, geniposide, and gardenoside components showed distinct rescue effect on memory loss. Further investigation on adding gardenoside into a formula of Ganoderma lucidum, Panax notoginseng and Panax ginseng (GPP) also support its therapeutic effects on memory improvement. Interestingly, the application of GPP and gardenoside did not alter the accumulation of Abeta proteins but suppressed the expression of immune-related genes in the brain. These results revealed the importance and relevancy of anti-inflammation process and the underlying mechanisms on rescuing memory deficits, suggesting the potential therapeutic use of the improved GPP formulation in improving cognition in defined population in the future.

Label Free Quantitative Mass Spectrometry Identifies Processes Linked to Platelet Degranulation As Early Events during Platelet Storage

BackgroundPlatelet concentrates (PCs) are stored at room temperature to preserve their biological activity. To minimize the risk of bacterial outgrowth, storage time is limited to 7 days. It is well-established that prolonged storage of PCs results in modifications that result in a decreased hemostatic efficacy. This loss of platelet functionality during storage is commonly referred to as the platelet storage lesion (PSL). Typical events linked to development of the PSL are shape changes, platelet activation and loss of receptors crucial for platelet functionality. Two-dimensional (2D) differential gel electrophoresis (DIGE), isotope tagging and isotope-coded affinity tagging (ICAT) have been previously used to monitor changes in protein composition during storage. These studies have provided valuable insights into the changes associated with the PSL, however, these studies generally focused on a limited set of proteins.AimWe aimed to generate an overview of changes in the platelet proteome during storage using label free quantitative mass spectrometry. Furthermore, we employed Gene ontology (GO) enrichment analysis to identify pathways and biological processes that were linked to development of the PSL.MethodsThree independently pooled PCs were stored in plasma under standard blood bank conditions for 16 days. Tryptic peptides were separated by nanoscale C18 reverse phase chromatography coupled on line to an Orbitrap Fusion Tribrid mass spectrometer. The RAW mass spectrometry files were processed with the MaxQuant computational platform. The global changes in protein level during platelet storage were assessed employing the analysis-of-variance functions of PERSEUS. Gene ontology enrichment analysis of biological processes, molecular functions and cellular compartments of the significantly different proteins was performed using the Cytoscape plug-in BiNGO.ResultsA total number of 2501 proteins was detected in all 3 biological replicates in at least one of the time points analyzed. The analysis showed that 18 proteins were down-regulated over time, whereas the level of 3 proteins was found to increase. CytoScape BinGo analysis of these significantly downregulated proteins revealed that the majority of this set was linked to GO-terms platelet degranulation, secretion and regulated exocytosis. This set of proteins included von Willebrand factor (VWF), serglycin (SRGN), SPARC, amyloid beta A4 protein (APP), multimerin-1 (MMRN1) and platelet factor 4 (PF4). A significant decline in these protein levels was observed at day 5 of storage, suggesting that release of α-granules is a relatively early event during platelet storage. At day 5 also a marked decline in S100A9 was observed. S100A9 has been implicated in degranulation in neutrophils, and may therefore also be linked to platelet granule release. Levels of membrane surface platelet glycoproteins such as glycoprotein Ibα did not significantly change at day 5. Only one single protein, histone H2A, was found to be consistently decreased already at two days of storage, but the significance of this finding is not clear. Upon prolonged storage (13 and 16 days) an increase in the level of α-2-macroglobulin (A2M), immunoglobulin M (IGM) and glycogenin-1 (GYG1) was observed suggesting that platelets acquire an (increased) potential to bind and/or internalize proteins from their environment. Consistent with this notion we also detected significant levels of several serine protease inhibitors, although levels of these proteins did not change upon storage.ConclusionsOverall, our findings highlight dynamic changes in protein composition of platelets during storage. Our data provide evidence for sustained release of α-granules over time which becomes significant at day 5. Our data also suggest that during storage, platelets can bind or ingest proteins from their environment which may have impact on the hemostatic properties of stored platelets. DisclosuresLeebeek:CSL Behring: Membership on an entity's Board of Directors or advisory committees, Research Funding; Baxalta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Dutch Hemphilia Foundation: Research Funding.

Spinal Cord Stimulation Alters Protein Levels in the Cerebrospinal Fluid of Neuropathic Pain Patients: A Proteomic Mass Spectrometric Analysis

Electrical neuromodulation by spinal cord stimulation (SCS) is a well-established method for treatment of neuropathic pain. However, the mechanism behind the pain relieving effect in patients remains largely unknown. In this study, we target the human cerebrospinal fluid (CSF) proteome, a little investigated aspect of SCS mechanism of action. Two different proteomic mass spectrometry protocols were used to analyze the CSF of 14 SCS responsive neuropathic pain patients. Each patient acted as his or her own control and protein content was compared when the stimulator was turned off for 48 hours, and after the stimulator had been used as normal for three weeks. Eighty-six proteins were statistically significantly altered in the CSF of neuropathic pain patients using SCS, when comparing the stimulator off condition to the stimulator on condition. The top 12 of the altered proteins are involved in neuroprotection (clusterin, gelsolin, mimecan, angiotensinogen, secretogranin-1, amyloid beta A4 protein), synaptic plasticity/learning/memory (gelsolin, apolipoprotein C1, apolipoprotein E, contactin-1, neural cell adhesion molecule L1-like protein), nociceptive signaling (neurosecretory protein VGF), and immune regulation (dickkopf-related protein 3). Previously unknown effects of SCS on levels of proteins involved in neuroprotection, nociceptive signaling, immune regulation, and synaptic plasticity are demonstrated. These findings, in the CSF of neuropathic pain patients, expand the picture of SCS effects on the neurochemical environment of the human spinal cord. An improved understanding of SCS mechanism may lead to new tracks of investigation and improved treatment strategies for neuropathic pain.

Developmental alcohol exposure leads to a persistent change on astrocyte secretome.

Fetal alcohol spectrum disorder is the most common cause of mental disabilities in the western world. It has been quite established that acute alcohol exposure can dramatically affect astrocyte function. Because the effects of early alcohol exposure on cell physiology can persist into adulthood, we tested the hypothesis that ethanol exposure in ferrets during a period equivalent to the last months of human gestation leads to persistent changes in astrocyte secretome invitro. Animals were treated with ethanol (3.5g/kg) or saline between postnatal day (P)10-30. At P31, astrocyte cultures were made and cells were submitted to stable isotope labeling by amino acids. Twenty-four hour conditioned media of cells obtained from ethanol- or saline-treated animals (ET-CM or SAL-CM) were collected and analyzed by quantitative mass spectrometry in tandem with liquid chromatography. Here, we show that 65 out of 280 quantifiable proteins displayed significant differences comparing ET-CM to SAL-CM. Among the 59 proteins that were found to be reduced in ET-CM we observed components of the extracellular matrix such as laminin subunits α2, α4, β1, β2, and γ1 and the proteoglycans biglycan, heparan sulfate proteoglycan 2, and lumican. Proteins with trophic function such as insulin-like growth factor binding protein 4, pigment epithelium-derived factor, and clusterin as well as proteins involved on modulation of proteolysis such as metalloproteinase inhibitor 1 and plasminogen activator inhibitor-1 were also reduced. In contrast, pro-synaptogeneic proteins like thrombospondin-1, hevin as well as the modulator of extracelular matrix expression, angiotensinogen, were found increased in ET-CM. The analysis of interactome maps through ingenuity pathway analysis demonstrated that the amyloid beta A4 protein precursor, which was found reduced in ET-CM, was previously shown to interact with ten other proteins that exhibited significant changes in the ET-CM. Taken together our results strongly suggest that early exposure to teratogens such as alcohol may lead to an enduring change in astrocyte secretome. Despite efforts in prevention, fetal alcohol spectrum disorders are a major cause of mental disabilities. Here, we show that developmental exposure to alcohol lead to a persistent change in the pattern of proteins secreted (secretome) by astrocytes. This study is also the first mass spectrometry-based assessment of the astrocyte secretome in a gyrencephalic animal. Cover Image for this issue: doi: 10.1111/jnc.13320.

Effect of Xinjiang Uyghur Vernonia anthelmintica Willd Injection Treatment with Silicosis Fibrosis.

Objective. To observe the curative effect of VAWI on Xinjiang Uygur patients with silicosis fibrosis. Methods. After we diagnosed the 40 patients with the first phase of silicosis, we randomly divided them into two groups: the basic treatment group (group A, n = 20) and the VAWI group (group B, n = 20). At the same time, we selected the age-matched healthy patients (n = 20). We applied the combined protein chip with SELDI-TOF-MS to carry out the serum analysis. The data were analyzed throughout data preprocessing, difference in PEAK screening, hierarchical cluster analysis, and Principal Component Analysis (PCA). We built decision tree model and predict the difference between the PEAK corresponding proteins. Results. The proteins peaks corresponding to name, predicted protein, and gene name were as follows: M2001_69, amyloid beta a4 protein, APP, and M2017_02, amyloid beta a4 protein, APP. The different expression of proteins in patients with silicosis was found before and after with VAWI treatment. The predicted proteins were as follows: M1982_50, amyloid beta a4 protein, APP; M3164_50, fibrinogen alpha chain frag, FGA; M3379_28, fibrinogen alpha chain frag, FGA; and so on. Conclusion. VAWI presented curative effect on patients with silicosis fibrosis via the alternation of proteins expression in serum.

Protein expression in dairy cows with and without subclinical hypocalcaemia

AIM: To determine differences in plasma proteomic profiles between healthy cows and those with subclinical hypocalcaemia within 12 hours after calving, and thereby explore the underlying biological mechanism of subclinical hypocalcaemia in dairy cows.METHODS: Plasma samples were collected within 6 hours of calving from Holstein cows on a farm in Heilongjiang, China; 32 with subclinical hypocalcaemia (plasma calcium concentration 1.38–2.00 mmol/L and no clinical signs) and 59 control cows (plasma calcium concentration 2.10–2.8 mmol/L). Plasma samples were applied to weak cationic exchange protein chips for protein profiling by surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF-MS), and the data were analysed using the PBS-IIC system. The amplitude of peaks for the two groups were compared using the Wilcoxon sum-rank test, and the mass-to-charge ratio of the peaks that differed was used to identify peptide fragments using the Swiss-Prot protein database.RESULTS: Seven peaks were identified in the subclinical hypocalcaemia group that differed from those of the control group (p<0.001), that represented six unique proteins. Expression of serum albumin, fibrinogen alpha chain, amyloid beta A4 proteins and neurosecretory protein VGF were increased, and expression of apolipoprotein A-II and serum amyloid A proteins were decreased in the subclinical hypocalcaemic cows compared with control cows.CONCLUSION: Use of SELDI-TOF-MS technology can effectively identify differences in plasma protein expression patterns in cows with subclinical hypocalcaemia. Neurosecretory protein VGF and amyloid beta A4 protein might represent useful biomarkers for diagnosis of subclinical hypocalcaemia.

Proteomic research of high-glucose-activated endothelial microparticles and related proteins to Alzheimer's disease.

The study was designed to discover the biological function of endotheliocyte-derived microparticles in diabetes condition. A quantitative shotgun proteomics methodology was performed to study the proteome of these high-glucose-activated endothelial microparticles. A total of 1428 proteins were identified, containing 1421 and 1423 proteins in control and high-glucose groups, respectively. According to the ExoCarta database, 669 proteins have previously been identified in microparticles. The proteins associated with disease were identified in this study, and notably, 30 proteins have been reported to be associated with Alzheimer's disease, including amyloid beta A4 protein. Besides, the peptide abundance of amyloid beta A4 protein from control group was much less than that from high-glucose group. In conclusion, this work revealed the proteome of endothelial microparticles in mimic diabetes condition and provided a new proteomic evidence for Alzheimer's disease to be counted as the type 3 diabetes.

Structural Studies of the Amyloid State of Proteins

Amyloid diseases, including Alzheimer's, Parkinson's, and the prion conditions, are each associated with a particular protein in fibrillar form. At the morphological level, these fibers appear similar and are termed "amyloid." We found that the adhesive segments of amyloid fibers are short protein sequences which form pairs of interdigitated, in-register beta sheets. These amyloid fibrils were long suspected to be the disease agents, but evidence suggests that in the neurodegenerative diseases, smaller, often transient and polymorphic oligomers are the toxic entities. We have identified a segment of the amyloid-forming protein, alphaB crystallin, which forms an oligomeric complex exhibiting properties of other amyloid oligomers: beta-sheet-rich structure, cytotoxicity, and recognition by an anti-oligomer antibody. The X-ray-derived atomic structure of the oligomer reveals a cylindrical barrel, formed from six anti-parallel, out-of-register protein strands, which we term a cylindrin. The cylindrin structure is compatible with sequence segments from the Abeta protein of Alzheimer's disease and from other amyloid proteins. Cylindrins offer models for the hitherto elusive structures of amyloid oligomers, and are distinct in structure from amyloid fibrils.

Hippocampal proteoglycans brevican and versican are linked to spatial memory of Sprague-Dawley rats in the morris water maze.

Proteoglycans (PGs) are major constituents of the extracellular matrix and have recently been proposed to contribute to synaptic plasticity. Hippocampal PGs have not yet been studied or linked to memory. The aim of the study, therefore, was to isolate and characterize rat hippocampal PGs and determine their possible role in spatial memory. PGs were extracted from rat hippocampi by anion-exchange chromatography and analyzed by nano LC-MS/MS. Twenty male Sprague-Dawley rats were tested in the morris water maze. PGs agrin, amyloid beta A4 protein, brevican, glypican-1, neurocan, phosphacan, syndecan-4, and versican were identified in the hippocampi. Brevican and versican levels in the membrane fraction were higher in the trained group, correlating with the time spent in the target quadrant. α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor GluR1 was co-precipitated with brevican and versican. Levels for a receptor complex containing GluR1 was higher in trained while GluR2 and GluR3-containing complex levels were higher in yoked rats. The findings provide information about the PGs present in the rat hippocampus, demonstrating that versican and brevican are linked to memory retrieval in the morris water maze and that PGs interact with α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor GluR1, which is linked to memory retrieval. Proteoglycans (PGs) are major constituents of the extracellular matrix of the brain and were proposed to contribute to synaptic plasticity. This report addressed PGs in rat hippocampus and suggests that PGs brevican and versican are linked to spatial memory, and form a complex with the GluR1 subunit of the AMPA receptor, a key signaling molecule in memory mechanisms.

Oxycodone‐induced neuronal degeneration (803.1)

Oxycodone (6‐deoxy‐7,8‐dehydro‐14‐hydroxy‐3‐O‐methyl‐6‐oxomorphine) is a semi synthetic opioid. It is most effective for treating patients with post‐surgical, cancer and chronic non‐malignant pain. Recently concern regarding effect of chronic opioid exposure on the development of neuronal degeneration has been emerged. We have investigated induction of biomarkers of brain pathology by chronic oxycodone exposure in rats. We observed significant mitochondrial dysfunction and increase in activated caspase 3 level in brain of rats treated with oxycodone. Recently, it was shown that opioid receptors may be involved in amyloid‐beta production that is one of the characteristics of Alzheimer disease. Thus, we monitored the level of amyloid beta A4 protein. We detected increased accumulation of amyloid beta A4 protein in both nucleus accumbens and cortex areas of oxycodone‐exposed rats. We also observed increase in a‐synuclein level in various brain areas after oxycodone treatment. These data indicates that chronic oxycodone exposure may contribute to premature development of neuronal degeneration in brain areas involved in motivational, memory and executive controls.