DYRK1A promotes viral entry of highly pathogenic human coronaviruses in a kinase-independent manner.

Identifying host genes essential for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has the potential to reveal novel drug targets and further our understanding of Coronavirus Disease 2019 (COVID-19). We previously performed a genome-wide CRISPR/Cas9 screen to identify proviral host factors for highly pathogenic human coronaviruses. Few host factors were required by diverse coronaviruses across multiple cell types, but DYRK1A was one such exception. Although its role in coronavirus infection was previously undescribed, DYRK1A encodes Dual Specificity Tyrosine Phosphorylation Regulated Kinase 1A and is known to regulate cell proliferation and neuronal development. Here, we demonstrate that DYRK1A regulates ACE2 and DPP4 transcription independent of its catalytic kinase function to support SARS-CoV, SARS-CoV-2, and Middle East Respiratory Syndrome Coronavirus (MERS-CoV) entry. We show that DYRK1A promotes DNA accessibility at the ACE2 promoter and a putative distal enhancer, facilitating transcription and gene expression. Finally, we validate that the proviral activity of DYRK1A is conserved across species using cells of nonhuman primate and human origin. In summary, we report that DYRK1A is a novel regulator of ACE2 and DPP4 expression that may dictate susceptibility to multiple highly pathogenic human coronaviruses.

The full spectrum tuning of fluorescent molecules via a one-pot multicomponent reaction.

Fluorogenic probes for imaging enable visualization and analysis of difficult-to-reach cells and organelles. However, there are limited efficient examples of tuning these fluorescent molecules to higher wavelengths. This is vital since different tissues are sensitive to varying wavelength emissions. To address this need, we report the discovery, tuning, structure-photophysical property relationships (SPPR), and time-dependent DFT (TD-DFT) computations of 400-700+ nm fluorescent pyrido[2',1':2,3]imidazo[4,5-c]isoquinolines and substituted imidazo[1,2-a]pyridin-3-amines. The syntheses involve the trimethylsilylcyanide (TMSCN) modified Groebke-Blackburn-Bienaymé (GBB) multicomponent reaction as well as the TMSCN modified GBB combined with subsequent condensation of an aldehyde, and Aza-Friedel-Crafts-Intramolecular Cyclization-Oxidation all in one pot. The SPPR reveals that electron-withdrawing strength in the para-position of the aminopyridine starting material has direct control over the absorption and fluorescence emission wavelengths of these molecules. The TD-DFT computations show the changes in the natural transition orbitals (NTOs) with differing substitutions to the parent molecule that dictate the observed excitations, emissions, and fluorescence intensities. These findings give insights and directions for tuning the fluorescent properties of these motifs for various uses as probes and imaging agents.

DYRK1A antagonists rescue degeneration and behavioural deficits of in vivo models based on amyloid-ß, Tau and DYRK1A neurotoxicity.

Alzheimer's disease (AD) involves pathological processing of amyloid precursor protein (APP) into amyloid-ß and microtubule associated protein Tau (MAPT) into hyperphosphorylated Tau tangles leading to neurodegeneration. Only 5% of AD cases are familial making it difficult to predict who will develop the disease thereby hindering our ability to treat the causes of the disease. A large population who almost certainly will, are those with Down syndrome (DS), who have a 90% lifetime incidence of AD. DS is caused by trisomy of chromosome 21 resulting in three copies of APP and other AD-associated genes, like dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A) overexpression. This implies that DYRK1a inhibitors may have therapeutic potential for DS and AD, however It is not clear how overexpression of each of these genes contributes to the pathology of each disease as well as how effective a DYRK1A inhibitor would be at suppressing any of these. To address this knowledge gap, we used Drosophila models with human Tau, human amyloid-ß or fly DYRK1A (minibrain (mnb)) neuronal overexpression resulting in photoreceptor neuron degeneration, premature death, decreased locomotion, sleep and memory loss. DYRK1A small molecule Type 1 kinase inhibitors (DYR219 and DYR533) were effective at suppressing these disease relevant phenotypes confirming their therapeutic potential.

The Omnipresence of DYRK1A in Human Diseases.

The increasing population will challenge healthcare, particularly because the worldwide population has never been older. Therapeutic solutions to age-related disease will be increasingly critical. Kinases are key regulators of human health and represent promising therapeutic targets for novel drug candidates. The dual-specificity tyrosine-regulated kinase (DYRKs) family is of particular interest and, among them, DYRK1A has been implicated ubiquitously in varied human diseases. Herein, we focus on the characteristics of DYRK1A, its regulation and functional role in different human diseases, which leads us to an overview of future research on this protein of promising therapeutic potential.

Sequential Knoevenagel [4+1] Cycloaddition-Condensation-Aza-Friedel-Crafts Intramolecular Cyclization: A 4-Center-3-Component Reaction Toward Tunable Fluorescent Indolizine Tetracycles.

A two-step multicomponent reaction oxidation protocol is reported herein, which affords novel tunable fluorescent tetracyclic indolizines. The procedure involves a novel 4-center-3-component reaction, which proceeds via a sequential Knoevenagel condensation, [4+1] cycloaddition, and imine condensation to afford imino-indolizines. Products then undergo cyclization and are oxidized in situ to afford fluorescent tetracycles, which are readily tunable through modification of diversity elements.

Oxidations of pyrrolidines and piperidines to afford CH-functionalized isopropyl-1-carboxylate congeners.

This article describes the action of iodine(III) reagents [diacetoxyiodobenzene, PhI(OAc)2, and iodosobenzene, (PhIO)n] in conjunction with TMSBr which act as functional bromine equivalents in unique oxidations of saturated, carbamate protected N-heterocycles. Interestingly, during this work, treatment of the same carbamates with molecular bromine alone afforded similar products, which were sequestered by the solvent methanol.

Suzuki Coupling of Protected Aryl Diazonium Ions: Expanding the Knowledge of Triazabutadiene Compatible Reactions.

Aryl diazonium ions are important in synthesis and chemical biology, and the acid-labile triazabutadiene can protect this handle for future use. We report a Suzuki coupling strategy that is compatible with the triazabutadiene scaffold, expanding the scope of synthetically available triazabutadienes. Shown herein, the triazabutadiene scaffold remains intact and reactive after coupling, as demonstrated by releasing the aryl diazonium ion to label a tyrosine-rich model protein.

5-Endo Trig Oxidative Radical Cyclizations of Ugi-3CR Products toward 1,4-Imidazolidinones.

A 5-endo trig oxidative radical cyclization of benzylamine-derived Ugi three-component reaction products rapidly affords imidazolidinones with three diversity elements. This adaptation of our previously described multicomponent reaction-oxidation methodology further showcases manipulation of the diversity elements in multicomponent reaction products via oxidative radical cyclizations, which generates highly decorated privileged heterocycles.

Breakthroughs in Medicinal Chemistry: New Targets and Mechanisms, New Drugs, New Hopes-5.

Breakthroughs in Medicinal Chemistry: New Targets and Mechanisms, New Drugs, New Hopes is a series of Editorials which is published on a biannual basis by the Editorial Board of the Medicinal Chemistry section of the journal Molecules [...].

Breakthroughs in Medicinal Chemistry: New Targets and Mechanisms, New Drugs, New Hopes-6.

Breakthroughs in Medicinal Chemistry: New Targets and Mechanisms, New Drugs, New Hopes is a series of Editorials that is published on a biannual basis by the Editorial Board of the Medicinal Chemistry section of the journal Molecules [...].

Exploring Ugi-Azide Four-Component Reaction Products for Broad-Spectrum Influenza Antivirals with a High Genetic Barrier to Drug Resistance.

Influenza viruses are respiratory pathogens that are responsible for seasonal influenza and sporadic influenza pandemic. The therapeutic efficacy of current influenza vaccines and small molecule antiviral drugs is limited due to the emergence of multidrug-resistant influenza viruses. In response to the urgent need for the next generation of influenza antivirals, we utilized a fast-track drug discovery platform by exploring multi-component reaction products for antiviral drug candidates. Specifically, molecular docking was applied to screen a small molecule library derived from the Ugi-azide four-component reaction methodology for inhibitors that target the influenza polymerase PAC-PB1N interactions. One hit compound 5 was confirmed to inhibit PAC-PB1N interactions in an ELISA assay and had potent antiviral activity in an antiviral plaque assay. Subsequent structure-activity relationship studies led to the discovery of compound 12a, which had broad-spectrum antiviral activity and a higher in vitro genetic barrier to drug resistance than oseltamivir. Overall, the discovery of compound 12a as a broad-spectrum influenza antiviral with a high in vitro genetic barrier to drug resistance is significant, as it offers a second line of defense to combat the next influenza epidemics and pandemics if vaccines and oseltamivir fail to confine the disease outbreak.

Aza-Riley Oxidation of Ugi-Azide and Ugi-3CR Products toward Vicinal Tricarbonyl Amides: Two-Step MCR-Oxidation Methodology Accessing Functionalized α,ß-Diketoamides and α,ß-Diketotetrazoles.

Direct oxidative deamination of glyoxal-derived Ugi-azide and Ugi three-component reaction products readily affords vicinal tricarbonyls (α,ß-diketoamides) and α,ß-diketotetrazoles with two diversity elements. This significant extension of our previously described multicomponent reaction-oxidative deamination methodology is proposed to proceed through a mechanistically distinct SeO2-mediated C-N oxidation derived from an active enol of α-amino-ß-ketone systems, effectively an aza-Riley oxidation. This methodology accesses diverse VTC systems from prototypical amines, glyoxaldehydes, and isocyanide building blocks in a mere two steps.

Breakthroughs in Medicinal Chemistry: New Targets and Mechanisms, New Drugs, New Hopes⁻4.

Breakthroughs in Medicinal Chemistry: New Targets and Mechanisms, New Drugs, New Hopes is a series of Editorials, which is published on a biannual basis by the Editorial Board of the Medicinal Chemistry section of the journal Molecules. [...].

Breakthroughs in Medicinal Chemistry: New Targets and Mechanisms, New Drugs, New Hopes-2.

Breakthroughs in Medicinal Chemistry: New Targets and Mechanisms, New Drugs, New Hopes is a series of Editorials, which are published on a biannual basis by the Editorial Board of the Medicinal Chemistry section of the journal Molecules [...].

Dyrk1 inhibition improves Alzheimer's disease-like pathology.

There is an urgent need for the development of new therapeutic strategies for Alzheimer's disease (AD). The dual-specificity tyrosine phosphorylation-regulated kinase-1A (Dyrk1a) is a protein kinase that phosphorylates the amyloid precursor protein (APP) and tau and thus represents a link between two key proteins involved in AD pathogenesis. Furthermore, Dyrk1a is upregulated in postmortem human brains, and high levels of Dyrk1a are associated with mental retardation. Here, we sought to determine the effects of Dyrk1 inhibition on AD-like pathology developed by 3xTg-AD mice, a widely used animal model of AD. We dosed 10-month-old 3xTg-AD and nontransgenic (NonTg) mice with a Dyrk1 inhibitor (Dyrk1-inh) or vehicle for eight weeks. During the last three weeks of treatment, we tested the mice in a battery of behavioral tests. The brains were then analyzed for the pathological markers of AD. We found that chronic Dyrk1 inhibition reversed cognitive deficits in 3xTg-AD mice. These effects were associated with a reduction in amyloid-ß (Aß) and tau pathology. Mechanistically, Dyrk1 inhibition reduced APP and insoluble tau phosphorylation. The reduction in APP phosphorylation increased its turnover and decreased Aß levels. These results suggest that targeting Dyrk1 could represent a new viable therapeutic approach for AD.

Synthesis of fluorescent heterocycles via a Knoevenagel/[4 + 1]-cycloaddition cascade using acetyl cyanide.

A concise one-pot three-component reaction that affords fluorescent indolizines, benzo[d]pyrrolo[2,1-b]thiazoles, and pyrrolo[1,2-a]pyrazines is reported. The methodology involves the formation of a heterocyclic 1-aza-1,3-diene derived from a Knoevenagel condensation between an aldehyde and 2-methyl-ene-cyano aza-heterocycles, followed by [4 + 1] cycloaddition of acetyl cyanide behaving as a non-classical isocyanide replacement.

Copper(i) catalyzed oxidative hydrolysis of Ugi 3-component and Ugi-azide reaction products towards 2° α-ketoamides and α-ketotetrazoles.

Herein, a two-step MCR-oxidation methodology accessing decorated 2° α-ketoamides and α-ketotetrazoles is described via a catalytic copper(i)-mediated C-N oxidation/acidic hydrolysis of Ugi-three-component and Ugi-azide reaction products. The ability to install diversity from aldehyde and isocyanide synthons allows rapid complexity generation. Of note, (1) 2° α-ketoamides are traditionally difficult to access and more so reminiscent of the endogenous peptide bonds. (2) The route to α-keto-tetrazoles is significantly shorter than that in previous reports.

Breakthroughs in Medicinal Chemistry: New Targets and Mechanisms, New Drugs, New Hopes.

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Oxidative Deaminations and Deisatinylations of Ugi-Azide and Ugi-3CR Products: A Two-Step MCR-Oxidation Protocol toward Functionalized α-Ketoamides and α-Ketotetrazoles.

A new postcondensation multicomponent reaction (MCR) methodology, comprising oxidative deaminations enabling access to multiple privileged carbonyl-containing scaffolds in two steps, is described. These protocols allow facile access to functionalized α-ketoamide and α-ketotetrazole small-molecule peptidomimetic-like building blocks from prototypical synthons with two points of diversity. Incorporation of chalcone and alkynyl moieties with further ring-forming reactions enables access to additional novel heterocyclic ring systems, including a unique and potentially highly pharmacologically relevant scaffold, a 1,2-selenazol-3(2H)-one.