Amyloidogenic proteins in Alzheimer's and Parkinson's disease. Interaction with chaperones and inflammation

Contains fulltext : 90826.pdf (publisher's version ) (Open Access)Radboud Universiteit Nijmegen, 21 september 2011Promotores : Padberg, G.W.A.M., Wevers, R.A. Co-promotores : Verbeek, M.M., Waal, R.M.W. de176 p

Effects of R-baclofen on the delta frequency band during active and passive behavior in rats

Contains fulltext : 64255.pdf (publisher's version ) (Open Access

MicroRNAs in Cerebrospinal Fluid as Potential Biomarkers for Parkinson's Disease and Multiple System Atrophy

Contains fulltext : 179586.pdf (publisher's version ) (Open Access

Small heat shock proteins induce a cerebral inflammatory reaction

Contains fulltext : 96353.pdf (publisher's version ) (Open Access)9 p

MicroRNA-29a Is a Candidate Biomarker for Alzheimer's Disease in Cell-Free Cerebrospinal Fluid

The identification of reliable biomarkers for Alzheimer's disease (AD) remains challenging. Recently, abnormal levels of microRNAs (miRNAs) miR-27a, miR-29a, miR-29b, and miR-125b in cerebrospinal fluid (CSF) of AD patients were reported. We aimed to confirm the biomarker potential of these miRNAs for AD diagnosis. Additionally, we examined the influence of blood contamination on CSF miRNA levels as potential confounding factor. We studied expression levels of the four miRNAs by quantitative PCR in CSF samples of AD patients and non-demented controls, and in blood-spiked CSF. Levels of miR-29a, but not of the other three miRNAs, were increased by a factor of 2.2 in CSF of AD patients. Spiking of small amounts of blood into CSF revealed that miR-27a and miR-29a, but not miR-125b levels were strongly influenced by the number of blood cells in the sample. In conclusion, miR-29a may be a candidate biomarker for AD, but only when used in cell-free CSF

Apolipoprotein E protects cultured pericytes and astrocytes from D-A beta(1-40)-mediated cell death

Item does not contain fulltextCerebral amyloid angiopathy (CAA) is a common pathological finding in Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis of the Dutch type; in this latter condition it is caused by deposition of mutated amyloid beta protein (Abeta Glu22Gln; D-Abeta(1-40)). Previously, we found a dependence of the Abeta-mediated toxicity and apolipoprotein E (apoE) production by cultured pericytes on apoE genotype. Given their close association with the cerebrovascular wall both astrocytes and pericytes may be involved in CAA development, a process that includes Abeta deposition and clearance and that may be affected by interaction with locally produced apolipoprotein E (apoE). Although astrocytes are regarded as the major source of apolipoprotein E (apoE) in the brain, also pericytes produce apoE. In this study we compared the apoE production capacity, the effects of apoE on D-Abeta(1-40) internalization, D-Abeta(1-40) cell surface accumulation and the vulnerability for D-Abeta(1-40)-induced toxicity of either cell type in order to quantify the relative contributions of astrocytes and pericytes in the various processes that contribute to CAA formation. Strikingly, cultured astrocytes produced only 3-10% of the apoE amounts produced by pericytes. Furthermore, pericytes with the apoE epsilon4 allele produced three times less apoE and were more vulnerable to D-Abeta(1-40) treatment than pericytes without an epsilon4 allele. Such relations were not observed with astrocytes in vitro. Both pericytes and astrocytes, however, were protected from Abeta-induced cytotoxicity by high levels of pericyte-derived apoE, but not recombinant apoE. In addition, pericyte-derived apoE dose-dependently decreased both internalization of Abeta and Abeta accumulation at the cell surface in either cell type. The present data suggest that apoE produced by pericytes, rather than astrocyte-produced apoE, modulates Abeta cytotoxicity and Abeta removal near the vasculature in the brain. Furthermore, since apoE production in pericytes is genotype dependent, this may contribute to the apoE genotype-dependent development of CAA in vivo

Effects of GABAergic drugs on the theta peak frequency during active behavior in rats

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Aggregation and cytotoxic properties towards cultured cerebrovascular cells of Dutch-mutated Abeta40 (DAbeta(1-40)) are modulated by sulfate moieties of heparin.

Contains fulltext : 88015.pdf (publisher's version ) (Closed access)Glycosaminoglycans (GAGs), in particular as part of heparan sulfate proteoglycans, are associated with cerebral amyloid angiopathy (CAA). Similarly, GAGs are also associated with the severe CAA found in patients suffering from hereditary cerebral hemorrhage with amyloidosis of the Dutch type (HCHWA-D), where the amyloid beta (Abeta) peptide contains the Dutch mutation (DAbeta(1-40)). This suggests a role for GAGs in vascular Abeta aggregation. It was the aim of this study to investigate the effect of different GAGs (heparin, chondroitin sulfate, heparan sulfate), the macromolecule dextran sulfate and, using desulfated heparins, the role of GAG sulfate moieties on the in vitro aggregation of CAA-associated DAbeta(1-40) and on DAbeta(1-40)-induced toxicity of cultured cerebrovascular cells. We also aimed to study the in vivo distribution of various sulfated heparan sulfate GAG epitopes in CAA. Of all GAGs tested, heparin was the strongest inducer of aggregation of DAbeta(1-40) in the different aggregation assays, with both heparin and heparan sulfate reducing Abeta-induced cellular toxicity. Furthermore, (partial) removal of the sulfate moieties of heparin partially abolished the effects of heparin on aggregation and cellular toxicity, suggesting an essential role for the sulfate moieties in heparin. Finally, we demonstrated the in vivo association of sulfated heparan sulfate (HS) GAGs with CAA. We conclude that sulfate moieties within GAGs, like heparin and HS, have an important role in Abeta aggregation in CAA and in Abeta-mediated toxicity of cerebrovascular cells.1 april 201