High throughput screening for SARS-CoV-2 helicase inhibitors.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for nearly 7 million deaths worldwide since its outbreak in late 2019. Even with the rapid development and production of vaccines and intensive research, there is still a huge need for specific anti-viral drugs that address the rapidly arising new variants. To address this concern, the National Institute of Allergy and Infectious Diseases (NIAID) established nine Antiviral Drug Discovery (AViDD) Centers, tasked with exploring approaches to target pathogens with pandemic potential, including SARS-CoV-2.

SARS-CoV-2 M inhibitor identification using a cellular gain-of-signal assay for high-throughput screening.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2, SARS2) is responsible for the COVID-19 pandemic and infections that continue to affect the lives of millions of people worldwide, especially those who are older and/or immunocompromised. The SARS2 main protease enzyme, M (also called 3C-like protease, 3CL), is a bona fide drug target as evidenced by potent inhibition with nirmatrelvir and ensitrelvir, the active components of the drugs Paxlovid and Xocova, respectively. However, the existence of nirmatrelvir and ensitrelvir-resistant isolates underscores the need to develop next-generation drugs with different resistance profiles and/or distinct mechanisms of action.

Optimization of Electronic Health Record Usability Through a Department-Led Quality Improvement Process.

Background: Electronic health records (EHR) have become commonplace in medicine. A disconnect between developers and users while creating the interface often fails to create a product that captures clinical workflow, and issues become apparent with implementation. Optimization allows collaboration of clinicians and informaticists after implementation, but documentation of success has only been at the institutional level.

An ADAM10 Exosite Inhibitor Is Efficacious in an In Vivo Collagen-Induced Arthritis Model.

Rheumatoid arthritis is a systemic autoimmune inflammatory disease that affects millions of people worldwide. There are multiple disease-modifying anti-rheumatic drugs available; however, many patients do not respond to any treatment. A disintegrin and metalloproteinase 10 has been suggested as a potential new target for RA due to its role in the release of multiple pro- and anti-inflammatory factors from cell surfaces.

1,3-Diphenylureido hydroxamate as a promising scaffold for generation of potent antimalarial histone deacetylase inhibitors.

We report a series of 1,3-diphenylureido hydroxamate HDAC inhibitors evaluated against sensitive and drug-resistant P. falciparum strains. Compounds 8a-d show potent antiplasmodial activity, indicating that a phenyl spacer allows improved potency relative to cinnamyl and di-hydrocinnamyl linkers.

HDAC specificity and kinase off-targeting by purine-benzohydroxamate anti-hematological tumor agents.

A series of hybrid inhibitors, combining pharmacophores of known kinase inhibitors bearing anilino-purines (ruxolitinib, ibrutinib) and benzohydroxamate HDAC inhibitors (nexturastat A), were generated in the present study. The compounds have been synthesized and tested against solid and hematological tumor cell lines. Compounds 4d-f were the most promising in cytotoxicity assays (IC ≤ 50 nM) vs.

Neutral ceramidase-active site inhibitor chemotypes and binding modes.

Ceramides impact a diverse array of biological functions and have been implicated in disease pathogenesis. The enzyme neutral ceramidase (nCDase) is a zinc-containing hydrolase and mediates the metabolism of ceramide to sphingosine (Sph), both in cells and in the intestinal lumen. nCDase inhibitors based on substrate mimetics, for example C6-urea ceramide, have limited potency, aqueous solubility, and micelle-free fraction.

Hyperactivity in Mice Induced by Opioid Agonists with Partial Intrinsic Efficacy and Biased Agonism Administered Alone and in Combination with Morphine.

Opioid analgesics such as morphine and fentanyl induce mu-opioid receptor (MOR)-mediated hyperactivity in mice. Herein, we show that morphine, fentanyl, SR-17018, and oliceridine have submaximal intrinsic efficacy in the mouse striatum using S-GTPγS binding assays. While all of the agonists act as partial agonists for stimulating G protein coupling in striatum, morphine, fentanyl, and oliceridine are fully efficacious in stimulating locomotor activity; meanwhile, the noncompetitive biased agonists SR-17018 and SR-15099 produce submaximal hyperactivity.

High throughput screening for drugs that inhibit 3C-like protease in SARS-CoV-2.

The SARS coronavirus 2 (SARS-CoV-2) pandemic remains a major problem in many parts of the world and infection rates remain at extremely high levels. This high prevalence drives the continued emergence of new variants, and possibly ones that are more vaccine-resistant and that can drive infections even in highly vaccinated populations. The high rate of variant evolution makes clear the need for new therapeutics that can be clinically applied to minimize or eliminate the effects of COVID-19.

Identification of potent small molecule inhibitors of SARS-CoV-2 entry.

The severe acute respiratory syndrome coronavirus 2 responsible for COVID-19 remains a persistent threat to mankind, especially for the immunocompromised and elderly for which the vaccine may have limited effectiveness. Entry of SARS-CoV-2 requires a high affinity interaction of the viral spike protein with the cellular receptor angiotensin-converting enzyme 2. Novel mutations on the spike protein correlate with the high transmissibility of new variants of SARS-CoV-2, highlighting the need for small molecule inhibitors of virus entry into target cells.

G protein signaling-biased mu opioid receptor agonists that produce sustained G protein activation are noncompetitive agonists.

The ability of a ligand to preferentially promote engagement of one signaling pathway over another downstream of GPCR activation has been referred to as signaling bias, functional selectivity, and biased agonism. The presentation of ligand bias reflects selectivity between active states of the receptor, which may result in the display of preferential engagement with one signaling pathway over another. In this study, we provide evidence that the G protein-biased mu opioid receptor (MOR) agonists SR-17018 and SR-14968 stabilize the MOR in a wash-resistant yet antagonist-reversible G protein-signaling state.

Identification of Potential Modulators of the RGS7/Gβ5/R7BP Complex.

Regulators of G protein signaling (RGS) proteins serve as critical regulatory nodes to limit the lifetime and extent of signaling via G protein-coupled receptors (GPCRs). Previously, approaches to pharmacologically inhibit RGS activity have mostly focused on the inhibition of GTPase activity by interrupting the interaction of RGS proteins with the G proteins they regulate. However, several RGS proteins are also regulated by association with binding partners.

Atmospheric modelling of grass pollen rupturing mechanisms for thunderstorm asthma prediction.

The world's most severe thunderstorm asthma event occurred in Melbourne, Australia on 21 November 2016, coinciding with the peak of the grass pollen season. The aetiological role of thunderstorms in these events is thought to cause pollen to rupture in high humidity conditions, releasing large numbers of sub-pollen particles (SPPs) with sizes very easily inhaled deep into the lungs. The humidity hypothesis was implemented into a three-dimensional atmospheric model and driven by inputs from three meteorological models.

Does Sleep Position Influence Sleep-Disordered Breathing in Infants With Cleft Palate: A Feasibility Study?

Objective: Cleft palate (CP) can affect breathing, leading to sleep-disordered breathing (SDB). Sleep position can affect SDB, but the optimum sleep position for infants with CP is unknown. We aimed to determine the design of a pragmatic study to investigate the effect of the 2 routinely advised sleep positions in infants with CP on oxygen saturations.

Discovery and Optimization of Selective Inhibitors of Meprin α (Part II).

Meprin α is a zinc metalloproteinase (metzincin) that has been implicated in multiple diseases, including fibrosis and cancers. It has proven difficult to find small molecules that are capable of selectively inhibiting meprin a, or its close relative meprin b, over numerous other metzincins which, if inhibited, would elicit unwanted effects. We recently identified possible molecular starting points for meprin a-specific inhibition through an HTS effort (see part I, preceding paper).

Discovery and Optimization of Selective Inhibitors of Meprin α (Part I).

Meprin α and β are zinc-dependent proteinases implicated in multiple diseases including cancers, fibrosis, and Alzheimer's. However, until recently, only a few inhibitors of either meprin were reported and no inhibitors are in preclinical development. Moreover, inhibitors of other metzincins developed in previous years are not effective in inhibiting meprins suggesting the need for de novo discovery effort.

KLF5 Is Induced by FOXO1 and Causes Oxidative Stress and Diabetic Cardiomyopathy.

Rationale: Diabetic cardiomyopathy (DbCM) is a major complication in type-1 diabetes, accompanied by altered cardiac energetics, impaired mitochondrial function, and oxidative stress. Previous studies indicate that type-1 diabetes is associated with increased cardiac expression of KLF5 (Krüppel-like factor-5) and PPARα (peroxisome proliferator-activated receptor) that regulate cardiac lipid metabolism.

Objective: In this study, we investigated the involvement of KLF5 in DbCM and its transcriptional regulation.

Cardiomyocyte Krüppel-Like Factor 5 Promotes De Novo Ceramide Biosynthesis and Contributes to Eccentric Remodeling in Ischemic Cardiomyopathy.

Background: We previously showed that cardiomyocyte Krϋppel-like factor (KLF) 5 regulates cardiac fatty acid oxidation. As heart failure has been associated with altered fatty acid oxidation, we investigated the role of cardiomyocyte KLF5 in lipid metabolism and pathophysiology of ischemic heart failure.

Methods: Using real-time polymerase chain reaction and Western blot, we investigated the KLF5 expression changes in a myocardial infarction (MI) mouse model and heart tissue from patients with ischemic heart failure.

Comparison of morphine, oxycodone and the biased MOR agonist SR-17018 for tolerance and efficacy in mouse models of pain.

The mu opioid receptor-selective agonist, SR-17018, preferentially activates GTPγS binding over βarrestin2 recruitment in cellular assays, thereby demonstrating signaling bias. In mice, SR-17018 stimulates GTPγS binding in brainstem and produces antinociception with potencies similar to morphine. However, it produces much less respiratory suppression and mice do not develop antinociceptive tolerance in the hot plate assay upon repeated dosing.

Are convergence lines associated with high asthma presentation days? A case-control study in Melbourne, Australia.

Background: In epidemic thunderstorm asthma (ETSA) events a large number of people develop asthma symptoms over a short period of time. This is thought to occur because of a unique combination of high amounts of pollen and certain meteorological conditions. However, the exact cause and mechanism of epidemic thunderstorm asthma remains unclear.

Identification of Small-Molecule Inhibitors of Neutral Ceramidase (nCDase) via Target-Based High-Throughput Screening.

There is interest in developing inhibitors of human neutral ceramidase (nCDase) because this enzyme plays a critical role in colon cancer. There are currently no potent or clinically effective inhibitors for nCDase reported to date, so we adapted a fluorescence-based enzyme activity method to a high-throughput screening format. We opted to use an assay whereby nCDase hydrolyzes the substrate RBM 14-16, and the addition of NaIO4 acts as an oxidant that releases umbelliferone, resulting in a fluorescent signal.

Rescue of mutant gonadotropin-releasing hormone receptor function independent of cognate receptor activity.

Molecules that correct the folding of protein mutants, restoring their functional trafficking, are called pharmacoperones. Most are clinically irrelevant and possess intrinsic antagonist or agonist activity. Here, we identify compounds capable of rescuing the activity of mutant gonadotropin-releasing hormone receptor or GnRHR which, is sequestered within the cell and if dysfunctional leads to Hypogonadotropic Hypogonadism.

Oregano Oil and Its Principal Component, Carvacrol, Inhibit HIV-1 Fusion into Target Cells.

Oregano essential oil has long been known for its health-promoting benefits. Here, we report its activity against viral replication. Oregano oil was found to specifically inhibit lentiviruses, such as human and simian immunodeficiency viruses (HIV and SIV), irrespective of virus tropism, but not hepatitis C virus, adenovirus 5 (ADV5), Zika virus, and influenza (H1N1) virus.

A G protein signaling-biased agonist at the μ-opioid receptor reverses morphine tolerance while preventing morphine withdrawal.

It has been demonstrated that opioid agonists that preferentially act at μ-opioid receptors to activate G protein signaling over βarrestin2 recruitment produce antinociception with less respiratory suppression. However, most of the adverse effects associated with opioid therapeutics are realized after extended dosing. Therefore, we tested the onset of tolerance and dependence, and assessed for neurochemical changes associated with prolonged treatment with the biased agonist SR-17018.