197 research outputs found
Avermectins differentially affect ethanol intake and receptor function: implications for developing new therapeutics for alcohol use disorders
Abstract Our laboratory is investigating ivermectin (IVM) and other members of the avermectin family as new pharmacotherapeutics to prevent and/or treat alcohol use disorders (AUDs). Earlier work found that IVM significantly reduced ethanol intake in mice and that this effect likely reflects IVM's ability to modulate ligand-gated ion channels. We hypothesized that structural modifications that enhance IVM's effects on key receptors and/or increase its brain concentration should improve its anti-alcohol efficacy. We tested this hypothesis by comparing the abilities of IVM and two other avermectins, abamectin (ABM) and selamectin (SEL), to reduce ethanol intake in mice, to alter modulation of GABA A Rs and P2X 4 Rs expressed in Xenopus oocytes and to increase their ability to penetrate the brain. IVM and ABM significantly reduced ethanol intake and antagonized the inhibitory effects of ethanol on P2X 4 R function. In contrast, SEL did not affect either measure, despite achieving higher brain concentrations than IVM and ABM. All three potentiated GABA A R function. These findings suggest that chemical structure and effects on receptor function play key roles in the ability of avermectins to reduce ethanol intake and that these factors are more important than brain penetration alone. The direct relationship between the effect of these avermectins on P2X 4 R function and ethanol intake suggest that the ability to antagonize ethanol-mediated inhibition of P2X 4 R function may be a good predictor of the potential of an avermectin to reduce ethanol intake and support the use of avermectins as a platform for developing novel drugs to prevent and/or treat AUDs
Expanding Stereochemical and Skeletal Diversity Using Petasis Reactions and 1,3-Dipolar Cycloadditions
A short and modular synthetic pathway using intramolecular 1,3-dipolar cycloaddition reactions and yielding functionalized isoxazoles, isoxazolines, and isoxazolidines is described. The change in shape of previous compounds and those in this study is quantified and compared using principal moment-of-inertia shape analysis.Chemistry and Chemical Biolog
Petasis Three-Component Coupling Reactions of Hydrazides for the Synthesis of Oxadiazolones and Oxazolidinones
Requirements Analysis for an Open Research Knowledge Graph
Current science communication has a number of drawbacks and bottlenecks which
have been subject of discussion lately: Among others, the rising number of
published articles makes it nearly impossible to get an overview of the state
of the art in a certain field, or reproducibility is hampered by fixed-length,
document-based publications which normally cannot cover all details of a
research work. Recently, several initiatives have proposed knowledge graphs
(KGs) for organising scientific information as a solution to many of the
current issues. The focus of these proposals is, however, usually restricted to
very specific use cases. In this paper, we aim to transcend this limited
perspective by presenting a comprehensive analysis of requirements for an Open
Research Knowledge Graph (ORKG) by (a) collecting daily core tasks of a
scientist, (b) establishing their consequential requirements for a KG-based
system, (c) identifying overlaps and specificities, and their coverage in
current solutions. As a result, we map necessary and desirable requirements for
successful KG-based science communication, derive implications and outline
possible solutions.Comment: Accepted for publishing in 24th International Conference on Theory
and Practice of Digital Libraries, TPDL 202
Enantioselective Organocatalytic Three-Component Petasis Reaction among Salicylaldehydes, Amines, and Organoboronic Acids
Docosahexaenoic Acid-Derived Neuroprotectin D1 Induces Neuronal Survival via Secretase- and PPARγ-Mediated Mechanisms in Alzheimer's Disease Models
Neuroprotectin D1 (NPD1) is a stereoselective mediator derived from the omega-3 essential fatty acid docosahexaenoic acid (DHA) with potent inflammatory resolving and neuroprotective bioactivity. NPD1 reduces Aβ42 peptide release from aging human brain cells and is severely depleted in Alzheimer's disease (AD) brain. Here we further characterize the mechanism of NPD1's neurogenic actions using 3xTg-AD mouse models and human neuronal-glial (HNG) cells in primary culture, either challenged with Aβ42 oligomeric peptide, or transfected with beta amyloid precursor protein (βAPP)sw (Swedish double mutation APP695sw, K595N-M596L). We also show that NPD1 downregulates Aβ42-triggered expression of the pro-inflammatory enzyme cyclooxygenase-2 (COX-2) and of B-94 (a TNF-α-inducible pro-inflammatory element) and apoptosis in HNG cells. Moreover, NPD1 suppresses Aβ42 peptide shedding by down-regulating β-secretase-1 (BACE1) while activating the α-secretase ADAM10 and up-regulating sAPPα, thus shifting the cleavage of βAPP holoenzyme from an amyloidogenic into the non-amyloidogenic pathway. Use of the thiazolidinedione peroxisome proliferator-activated receptor gamma (PPARγ) agonist rosiglitazone, the irreversible PPARγ antagonist GW9662, and overexpressing PPARγ suggests that the NPD1-mediated down-regulation of BACE1 and Aβ42 peptide release is PPARγ-dependent. In conclusion, NPD1 bioactivity potently down regulates inflammatory signaling, amyloidogenic APP cleavage and apoptosis, underscoring the potential of this lipid mediator to rescue human brain cells in early stages of neurodegenerations
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