Microglial activation is a key feature in Alzheimer’s disease and is considered to contribute to progressive neuronal injury by release of neurotoxic products. The innate immune receptor Toll-like-receptor 4 (TLR4), localized on the surface of microglia, is a first-line host defense receptor against invading microorganisms. Here, we show that a spontaneous loss-of-function mutation in the Tlr4 gene strongly inhibits microglial and monocytic activation by aggregated Alzheimer amyloid peptide resulting in a significantly lower release of the inflammatory products IL-6, TNFα and nitric oxide. Treatment of primary murine neuronal cells with supernatant of amyloid peptide-stimulated microglia demonstrates that Tlr4 contributes to amyloid peptide-induced microglial neurotoxicity. In addition, stimulation experiments in transfected HEK293 cells allowed to define a tri-molecular receptor complex consisting of TLR4, MD-2 and CD14 necessary for full cellular activation by aggregated amyloid peptide. A clinical relevance of these findings is supported by a marked upregulation of Tlr4 mRNA in APP transgenic mice and by an increased expression of TLR4 in Alzheimer’s disease brain tissue associated with amyloid plaque deposition. Together, these observations provide the first evidence for a role of the key innate immune receptor, TLR4, in neuroinflammation in Alzheimer’s disease.

Background and Purpose-Considerable locoregional differences in stroke incidence exist even within countries. Based on data from a statewide stroke care quality monitoring project, we hypothesized a high stroke incidence mainly among younger age groups in the industrial city of Ludwigshafen am Rhein, Germany. To test this hypothesis and to provide data on stroke incidence and case-fatality rates, a population-based stroke register was initiated. were identified. The crude annual incidence rate per 1000 for first-ever stroke was 2.16 (95% CI 2.10 to 2.32). After age adjustment to the European population, incidence for first-ever stroke was 1.46 (95% CI 1.35 to 1.57; men: 1.63; 95% CI 1.46 to 1.81; women: 1.29; 95% CI 1.15 to 1.43). Crude annual incidence rates per 1000 were 1.86 for ischemic stroke, 0.19 for intracerebral hemorrhage, 0.05 for subarachnoid hemorrhage, and 0.05 for undetermined stroke. Case-fatality rates for first-ever stroke were 13.6%, 16.4%, and 23.2% at Days 28, 90, and 365, respectively. Conclusions-High crude incidence rates in our study reflect the rising burden of stroke in our aging population. Methods-TheAge-adjusted incidence rates were somewhat higher than those reported by recent studies from Western Europe, mainly due to higher incidence in subjects Ͻ65 years. (Stroke.

Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Conzelmann, S., Levai, O., Bode, B., Eisel, U., Raming, K., Breer, H., & Strotmann, J. (2000). A novel brain receptor is expressed in a distinct population of olfactory sensory neurons. European Journal of Neuroscience, 12(11), 3926-3934. https://doi.org/10.1046Neuroscience, 12(11), 3926-3934. https://doi.org/10. /j.1460Neuroscience, 12(11), 3926-3934. https://doi.org/10. -9568.2000 Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. AbstractThree novel G-protein-coupled receptor genes related to the previously described RA1c gene have been isolated from the mouse genome. Expression of these genes has been detected in distinct areas of the brain and also in the olfactory epithelium of the nose. Developmental studies revealed a differential onset of expression: in the brain at embryonic stage 17, in the olfactory system at stage E12. In order to determine which cell type in the olfactory epithelium expresses this unique receptor type, a transgenic approach was employed which allowed a coexpression of histological markers together with the receptor and thus visualization of the appropriate cell population. It was found that the receptor-expressing cells were located very close to the basal membrane of the epithelium; however, the cells extended a dendritic process to the epithelial surface and their axons projected into the main olfactory bulb where they converged onto two or three glomeruli in the dorsal and posterior region of the bulb. Thus, these data provide evidence that this unique type of receptor is expressed in mature olfactory neurons and suggests that it may be involved in the detection of special odour molecules. IntroductionG-protein-coupled receptors (GPCRs) are integral membrane proteins which mediate signals to the interior of cells via activation of heterotrimeric G-proteins, which subsequently interact with and activate various effector proteins, ultimately resulting in the physiological response. GPCRs are involved in the transduction of a large variety of extracellular signals as diverse as inorganic ions, peptides and lipids or sensory stimuli like photons or odourants. More and more orphan G-protein-coupled receptors have been made available by various cloning procedures such as PCR ampli®cation or systematic sequencing of cDNA libraries (Marchese et al., 1999).We have recently isolated a cDNA...

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