Inhibiting the protein-protein interaction (PPI) between the transcription factor Nrf2 and its repressor protein Keap1 has emerged as a promising strategy to target oxidative stress in diseases, including CNS disorders. Numerous non-covalent small-molecule Keap1-Nrf2 PPI inhibitors have been reported to date, but many feature suboptimal physicochemical properties for permeating the blood-brain barrier, while others contain problematic structural moieties. Here, we present the first side-by-side assessment of all reported Keap1-Nrf2 PPI inhibitor classes using fluorescence polarization (FP), thermal shift assay (TSA), and surface plasmon resonance (SPR)-and further evaluate the compounds in an NQO1 induction cell assay and in counter tests for non-boronate ester building block 41 as the crucial carbon skeleton-building step. Synthesis of the enol triflate using the one-step NaHMDS-mediated enolization/PhNTf2-induced trapping procedure reported in the patent application 39 was not efficient in our hands, giving low yield (43% vs. 88% reported in literature 39) and significant byproduct formation. We found that using a freshly-made LiHMDS as an alternative base gave a cleaner reaction and excellent yield (quantitative). The converging SM reaction step between 38 and 41 gave several wellknown by-products, including the boronic acid, aryl boronate homo-coupling product and protodeboronation product, but could still afford the desired cross-coupling product 42 in good yield (69% vs. 33% reported in literature 39). Catalytic hydrogenation to deprotect the carboxylic acid and reduce the alkene double bond diastereoselectively furnished only the cis-cyclohexane 43 in accordance with literature; 39 this was revealed by nuclear Overhauser effect (NOE) NMR (Supporting Information Figure S1). This facial selectivity can be explained by a steric directing effect of the carboxybenzyl group. The cyclohexane carboxylic acid of 43 was finally coupled with 2-butylpyrrolidine and the pyrazole carboxylic acid deprotected to give 10 as a mixture of four stereoisomers. Attempted separation of the two diastereoisomers by preparative HPLC was unsuccessful. In the patent application, purification by HPLC is reported to give two different fractions, each containing all four stereoisomers in slightly different proportions, of which one was directly tested as a mixture. 39 Having this literature result as a reference point, we did not proceed with further purification of 10.
We present the Danish Disease Trajectory Browser (DTB), a tool for exploring almost 25 years of data from the Danish National Patient Register. In the dataset comprising 7.2 million patients and 122 million admissions, users can identify diagnosis pairs with statistically significant directionality and combine them to linear disease trajectories. Users can search for one or more disease codes (ICD-10 classification) and explore disease progression patterns via an array of functionalities. For example, a set of linear trajectories can be merged into a disease trajectory network displaying the entire multimorbidity spectrum of a disease in a single connected graph. Using data from the Danish Register for Causes of Death mortality is also included. The tool is disease-agnostic across both rare and common diseases and is showcased by exploring multimorbidity in Down syndrome (ICD-10 code Q90) and hypertension (ICD-10 code I10). Finally, we show how search results can be customized and exported from the browser in a format of choice (i.e. JSON, PNG, JPEG and CSV).
Drug-induced liver injury (DILI) cannot be accurately predicted by animal models. In addition, currently available in vitro methods do not allow for the estimation of hepatotoxic doses or the determination of an acceptable daily intake (ADI). To overcome this limitation, an in vitro/in silico method was established that predicts the risk of human DILI in relation to oral doses and blood concentrations. This method can be used to estimate DILI risk if the maximal blood concentration (C max) of the test compound is known. Moreover, an ADI can be estimated even for compounds without information on blood concentrations. To systematically optimize the in vitro system, two novel test performance metrics were introduced, the toxicity separation index (TSI) which quantifies how well a test differentiates between hepatotoxic and non-hepatotoxic compounds, and the toxicity estimation index (TEI) which measures how well hepatotoxic blood concentrations in vivo can be estimated. In vitro test performance was optimized for a training set of 28 compounds, based on TSI and TEI, demonstrating that (1) concentrations where cytotoxicity first becomes evident in vitro (EC 10) yielded better metrics than higher toxicity thresholds (EC 50); (2) compound incubation for 48 h was better than 24 h, with no further improvement of TSI after 7 days incubation; (3) metrics were moderately improved by adding gene expression to the test battery; (4) evaluation of pharmacokinetic parameters demonstrated that total blood compound concentrations and the 95%-population-based percentile of C max were best suited to estimate human toxicity. With a support vector machine-based classifier, using EC 10 and C max as variables, the cross-validated sensitivity, specificity and accuracy for hepatotoxicity prediction were 100, 88 and 93%, respectively. Concentrations in the culture medium allowed extrapolation to blood concentrations in vivo that are associated with a specific probability of hepatotoxicity and the corresponding oral doses were obtained by reverse modeling. Application of this in vitro/in silico method to the rat hepatotoxicant pulegone resulted in an ADI that was similar to values previously established based on animal experiments. In conclusion, the proposed method links oral doses and blood concentrations of test compounds to the probability of hepatotoxicity.
Introduction Similar symptoms, comorbidities and suboptimal diagnostic tests make the distinction between different types of dementia difficult, although this is essential for improved work‐up and treatment optimization. Methods We calculated temporal disease trajectories of earlier multi‐morbidities in Alzheimer's disease (AD) dementia and vascular dementia (VaD) patients using the Danish National Patient Registry covering all hospital encounters in Denmark (1994 to 2016). Subsequently, we reduced the comorbidity space dimensionality using a non‐linear technique, uniform manifold approximation and projection. Results We found 49,112 and 24,101 patients that were diagnosed with AD or VaD, respectively. Temporal disease trajectories showed very similar disease patterns before the dementia diagnosis. Stratifying patients by age and reducing the comorbidity space to two dimensions, showed better discrimination between AD and VaD patients in early‐onset dementia. Discussion Similar age‐associated comorbidities, the phenomenon of mixed dementia, and misdiagnosis create great challenges in discriminating between classical subtypes of dementia.
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